WorldWideScience

Sample records for canal lock operations

  1. The impact of the New Panama Canal Locks on Texas ports and the Texas economy.

    Science.gov (United States)

    2017-10-01

    This report examines the first year transits through the new Panama Canal locks and its impact on Texas deep water ports. It finds that the canal is operating efficiently and can accommodate 14,000 TEU containerships and bulk vessels up to 125,000 to...

  2. 33 CFR 207.590 - Black Rock Canal and Lock at Buffalo, N.Y.; use, administration, and navigation.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Black Rock Canal and Lock at... Black Rock Canal and Lock at Buffalo, N.Y.; use, administration, and navigation. (a) The term “canal” when used in this section will mean all of the Black Rock Waterway, including Black Rock Lock, and all...

  3. Preliminary Hybrid Modeling of the Panama Canal: Operations and Salinity Diffusion

    Directory of Open Access Journals (Sweden)

    Luis Rabelo

    2012-01-01

    Full Text Available This paper deals with the initial modeling of water salinity and its diffusion into the lakes during lock operation on the Panama Canal. A hybrid operational model was implemented using the AnyLogic software simulation environment. This was accomplished by generating an operational discrete-event simulation model and a continuous simulation model based on differential equations, which modeled the salinity diffusion in the lakes. This paper presents that unique application and includes the effective integration of lock operations and its impact on the environment.

  4. Review of Ice-Control Methods at Lock 8, Welland Canal, Port Colborne, Ontario

    Science.gov (United States)

    2016-05-01

    to control ice and to reduce the possibility of ice causing a shipping vessel to get stuck or jammed in the lock chamber. The lock uses several... causing a shipping vessel to get stuck or jammed in the lock chamber. The lock uses several methods, including an air curtain to hold ice above the lock...4 2.2 Northbound traffic

  5. 33 CFR 207.170b - Apopka-Beauclair Navigation Lock in Apopka-Beauclair Canal in Lake County, Fla.; use...

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Apopka-Beauclair Navigation Lock in Apopka-Beauclair Canal in Lake County, Fla.; use, administration, and navigation. 207.170b Section... Lake County, Fla.; use, administration, and navigation. (a) The owner of or agency controlling the lock...

  6. SEGA mode locking, first experimental indications of operation

    NARCIS (Netherlands)

    Oldenbeuving, Ruud; Lee, Christopher James; Offerhaus, Herman L.; Boller, Klaus J.

    2012-01-01

    We present an alternative scheme for laser mode-locking and discuss its first experimental indications of operation. In this scheme, a large set of spatially separated gain (SEGA) media generate single-frequency continuous-wave (CW) light beams arranged as an approximately equidistant spectral

  7. Intra-operative augmented reality in distal locking.

    Science.gov (United States)

    Londei, Roberto; Esposito, Marco; Diotte, Benoit; Weidert, Simon; Euler, Ekkehard; Thaller, Peter; Navab, Nassir; Fallavollita, Pascal

    2015-09-01

    To design an augmented reality solution that assists surgeons during the distal locking of intramedullary nailing procedures. Traditionally, the procedure is performed under X-ray guidance and requires a significant amount of time and radiation exposure. To absolve these complications, we propose video guidance that allows surgeons to achieve both the down-the-beam position of the intramedullary nail and its subsequent locking. For the down-the-beam position, the IM nail pose in X-ray is calculated using a 2D/3D registration scheme and later related to the patient leg pose which is calculated using video-tracked AR markers. For the distal locking, surgeons use an augmented radiolucent drill in which its tip position is detected and tracked in real-time under video guidance. To evaluate the feasibility of our solution, we performed a preclinical study on dry bone phantom with the participation of four clinicians. Participants achieved 100 % success rate in the down-the beam positioning and 93 % success rate in distal locking using only two X-ray images in 100 s. We confirmed that intra-operative navigation using augmented reality provides an alternative way to perform distal locking in a safe and timely manner.

  8. IMPACT OF CANAL DESIGN LIMITATIONS ON WATER DELIVERY OPERATIONS AND AUTOMATION

    Science.gov (United States)

    Irrigation canals are often designed for water transmission. The design engineer simply ensures that the canal will pass the maximum design discharge. However, irrigation canals frequently operated far below design capacity. Because demands and the distribution of flow at bifurcations (branch points...

  9. 49 CFR 236.207 - Electric lock on hand-operated switch; control.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Electric lock on hand-operated switch; control... switch; control. Electric lock on hand-operated switch shall be controlled so that it cannot be unlocked until control circuits of signals governing movements over such switch have been opened. Approach or...

  10. 33 CFR 207.640 - Sacramento Deep Water Ship Channel Barge Lock and Approach Canals; use, administration, and...

    Science.gov (United States)

    2010-07-01

    ... lock. All boats, when in the lock, shall be moored to the fastenings provided for that purpose, by bow and stern lines and other spring lines as may be necessary, and the lines shall not be let go until...

  11. Versatile mode-locked fiber laser with switchable operation states of bound solitons.

    Science.gov (United States)

    Zou, Xin; Qiu, Jifang; Wang, Xiaodong; Ye, Zi; Shi, Jindan; Wu, Jian

    2016-06-01

    Bound states of two solitons are among the typical forms of bound states and can be observed in various operation states of mode-locked fiber lasers. We experimentally investigated bound solitons (BSs) in a passively mode-locked erbium-doped fiber laser based on a semiconductor saturable absorber mirror, whose operation states can be switched among multiple pulses, passively harmonic mode-locking, and "giant pulses" by simply adjusting the in-line polarization controller with the pump power fixed. Up to four pulses, fourth-order harmonic mode-locking (HML), and a "giant pulse" with four BSs were obtained with increasing pump power. Experimental results showed a correlative relationship among those operation states (N pulses/Nth-order HML/"giant pulses" of N bound solitons) at different pump power levels. The birefringence induced by the erbium-doped fiber inside the laser cavity played a vital role in the transitions of those operation states.

  12. Influence of root canal instrumentation and obturation techniques on intra-operative pain during endodontic therapy.

    Science.gov (United States)

    Martín-González, Jenifer; Echevarría-Pérez, Marta; Sánchez-Domínguez, Benito; Tarilonte-Delgado, Maria-Luisa; Castellanos-Cosano, Lizett; López-Frías, Francisco-Javier; Segura-Egea, Juan-Jose

    2012-09-01

    To analyse the influence of root canal instrumentation and obturation techniques on intra-operative pain experienced by patients during endodontic therapy. A descriptive cross-sectional study was carried out in Ponferrada and Sevilla, Spain, including 80 patients (46 men and 34 women), with ages ranged from 10 to 74 years, randomly recruited. Patient gender and age, affected tooth, pulpal diagnosis, periapical status, previous NSAID or antibiotic (AB) treatment, and root canal instrumentation and obturation techniques were recorded. After root canal treatment (RCT), patients completed a 10-cm visual analogue scale (VAS) that ranked the level of pain. Results were analysed statistically using the Chi-square and ANOVA tests and logistic regression analysis. The mean pain level during root canal treatment was 2.9±3.0 (median=2) in a VAS between 0 and 10. Forty percent of patients experienced no pain. Gender, age, arch, previous NSAIDs or AB treatment and anaesthetic type did not influence significantly the pain level (p>0.05). Pain during root canal treatment was significantly greater in molar teeth (OR=10.1; 95% C.I.=1.6-63.5; p=0.013). Root canal instrumentation and obturation techniques did not affect significantly patients' pain during root canal treatment (p>0.05). Patients feel more pain when RCT is carried out on molar teeth. The root canal instrumentation and obturation techniques do not affect significantly the patients' pain during RCT.

  13. 33 CFR 207.680 - Willamette River, Oreg.; use, administration, and navigation of canal and locks at Willamette...

    Science.gov (United States)

    2010-07-01

    ... district engineer. In case of emergency, however, the lockmaster shall have authority to take such steps as... the lockmaster's office. Notice to vessels desiring lockage will be given by red and green traffic lights. Vessels may enter locks on green lights, but must await green signal when lights are red...

  14. 77 FR 12514 - Drawbridge Operation Regulation; Hood Canal, WA

    Science.gov (United States)

    2012-03-01

    ... blue. In the ``Document Type'' drop down menu select ``Proposed Rules'' and insert ``USCG-2012-0074... standards are technical standards (e.g., specifications of materials, performance, design, or operation...

  15. Burst fractures of the thoracolumbar spine : changes of the spinal canal during operative treatment and follow-up

    NARCIS (Netherlands)

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

    Although multiple studies have concluded operative decompression of a traumatically narrowed spinal canal is not indicated because of spontaneous remodeling, instrumental decompression is frequently used as part of the operative treatment of spinal fractures. To investigate the process of

  16. McHale Operation in Patients with Neglected Hip Dislocations: The Importance of Locking Plates

    Directory of Open Access Journals (Sweden)

    Mark Eidelman

    2014-01-01

    Full Text Available Neglected hip dislocation in patients with cerebral palsy is a challenge for the pediatric orthopedic surgeon. Many patients experience pain, limitation of hip motion, and sitting and hygiene problems. Arthrodesis, proximal femoral head resection, and subtrochanteric valgus osteotomy are effective salvage procedures for patients with painful hip dislocation and restricted hip motion when reconstruction of the hip is not possible. Osteopenia is one of the problems that can complicate the postoperative course in these patients. Postoperative cast immobilization may further worsen the osteopenia and can predispose to fractures of the femur after cast removal. Standard plating of the proximal osteotomy may not always provide adequate stability of the fixation. In order to prevent postoperative osteoporotic fractures we use locking plates, without casting. Since 2003 until 2011, we operated on 9 patients (14 hips with painful neglected hip dislocations. The first three patients (five hips were operated on using standard nonlocking plates. All other patients (nine hips were operated on using locking plates. During the followup, the hardware failed in one of these cases. All patients treated with locking plates had not been casted postoperatively, and none had loss of fixation or fractures during the followup.

  17. Effect of adductor-canal-blockade on established, severe post-operative pain after total knee arthroplasty

    DEFF Research Database (Denmark)

    Jaeger, P; Grevstad, Ulrik; Henningsen, Maja

    2012-01-01

    In this proof-of-concept study, we investigated the effect of the predominantly sensory adductor-canal-blockade on established pain in the early post-operative period after total knee arthroplasty (TKA). We hypothesised that the adductor-canal-blockade would reduce pain during flexion of the knee...

  18. Influence of root canal instrumentation and obturation techniques on intra-operative pain during endodontic therapy

    OpenAIRE

    Martín González, Jenifer; Echevarría Pérez, Marta; Sánchez Domínguez, Benito; Tarilonte Delgado, María Luisa; Castellanos Cosano, Lizett; López Frias, Javier; Segura-Egea, Juan J.

    2012-01-01

    Objective: To analyse the influence of root canal instrumentation and obturation techniques on intra-operative pain experienced by patients during endodontic therapy. Method and Materials: A descriptive cross-sectional study was carried out in Ponferrada and Sevilla, Spain, including 80 patients (46 men and 34 women), with ages ranged from 10 to 74 years, randomly recruited. Patient gender and age, affected tooth, pulpal diagnosis, periapical status, previous NSAID or antibiotic (AB) treatmen...

  19. Influence of output power of a spin torque oscillator on phase locked loop operation

    Science.gov (United States)

    Tamaru, Shingo; Kubota, Hitoshi; Yakushiji, Kay; Fukushima, Akio; Yuasa, Shinji

    2016-09-01

    This work investigates the influence of the output power of a spin torque oscillator (STO) on the operation of a phase locked loop (PLL) circuit. Timing jitter and minimum output power for stable PLL operation determined by Johnson noise and shot noise are first theoretically calculated, and compared with experimental results. The theory and experiment show a reasonably good agreement, indicating that smaller than -50 dBm (10 nW), or -60 dBm (1 nW) when a low pass filter is used, of output power is sufficient for stable PLL operation if a large timing jitter is acceptable. However, it is also shown that a large output power is needed to suppress timing jitter down to the level comparable to state-of-the-art commercial PLL circuits. The estimate of minimum output power for stable PLL operation is verified by intentionally attenuating the STO output signal down to -55 dBm (3.2 nW) and demonstrating a stable phase locked oscillation.

  20. Continuous adductor-canal-blockade for adjuvant post-operative analgesia after major knee surgery: preliminary results

    DEFF Research Database (Denmark)

    Lund, J; Jenstrup, M T; Jæger, P

    2011-01-01

    Because both the saphenous nerve and in part the obturator nerve are traversing the adductor canal of the thigh, we hypothesised that repeated administration of a local anaesthetic (LA) into this aponeurotic space could be a useful option for post-operative analgesia after knee replacement surgery......-canal-blockade may be a valuable adjunct for post-operative analgesia after major knee surgery. These preliminary results should be confirmed in randomised, controlled trials....

  1. Reduced group delay dispersion in quantum dot passively mode-locked lasers operating at elevated temperature

    Science.gov (United States)

    Mee, J. K.; Raghunathan, R.; Murrell, D.; Braga, A.; Li, Y.; Lester, L. F.

    2014-09-01

    A detailed study of the pulse characteristics emitted from a monolithic Quantum Dot (QD) passively Mode-Locked Laser (MLL) has been performed using a state-of-the-art Frequency Resolved Optical Gating (FROG) pulse measurement system. While traditionally the time-domain pulse characteristics of semiconductor MLLs have been studied using digital sampling oscilloscope or intensity autocorrelation techniques, the FROG measurements allow for simultaneous characterization of time and frequency, which has been shown to be necessary and sufficient for true determination of mode-locked stability. In this paper, FROG pulse measurements are presented on a two-section QD MLL operating over wide temperature excursions. The FROG measurement allows for extraction of the temporal and spectral intensity and phase profiles from which the Group Delay Dispersion (GDD) can be determined. The magnitude of the GDD is found to decrease from 16.1 to 3.5 ps/nm when the temperature is increased from 20 to 50 oC, mirroring the trend of pulse width reduction at elevated temperature, which has been shown to correlate strongly with reduced unsaturated absorption. The possibility to further optimize pulse generation via intra-cavity dispersion compensation in a novel three-section MLL design is also examined, and shows strong potential toward providing valuable insight into the optimal cavity designs and operating parameters for QD MLLs.

  2. Multiple-Pulse Operation and Bound States of Solitons in Passive Mode-Locked Fiber Lasers

    Directory of Open Access Journals (Sweden)

    A. Komarov

    2012-01-01

    Full Text Available We present results of our research on a multiple-pulse operation of passive mode-locked fiber lasers. The research has been performed on basis of numerical simulation. Multihysteresis dependence of both an intracavity energy and peak intensities of intracavity ultrashort pulses on pump power is found. It is shown that the change of a number of ultrashort pulses in a laser cavity can be realized by hard as well as soft regimes of an excitation and an annihilation of new solitons. Bound steady states of interacting solitons are studied for various mechanisms of nonlinear losses shaping ultrashort pulses. Possibility of coding of information on basis of soliton trains with various bonds between neighboring pulses is discussed. The role of dispersive wave emitted by solitons because of lumped intracavity elements in a formation of powerful soliton wings is analyzed. It is found that such powerful wings result in large bounding energies of interacting solitons in steady states. Various problems of a soliton interaction in passive mode-locked fiber lasers are discussed.

  3. Panama Canal Watershed Experiment- Agua Salud Project

    Science.gov (United States)

    Stallard, Robert F.; Ogden, Fred L.; Elsenbeer, Helmut; Hall, Jefferson S.

    2010-01-01

    The Agua Salud Project utilizes the Panama Canal’s (Canal) central role in world commerce to focus global attention on the ecosystem services provided by tropical forests. The Canal was one of the great engineering projects in the world. Completed in 1914, after almost a decade of concerted effort, its 80 km length greatly shortened the voyage between the Atlantic and Pacific Oceans. An entire class of ships, the Panamax, has been constructed to maximize the amount of cargo that can be carried in a Canal passage. In today’s parlance, the Canal is a “green” operation, powered largely by water (Table 1). The locks, three pairs on each end with a net lift of 27 meters, are gravity fed. For each ton of cargo that is transferred from ocean to ocean, about 13 tons of water (m3) are used. Lake Gatún forms much of the waterway in the Canal transect. Hydroelectricity is generated at the Gatún dam, whenever there is surplus water, and at Madden Dam (completed in 1936) when water is transferred from Lake Alhajuela to Lake Gatún. The Canal watershed is the source of drinking water for Panama City and Colon City, at either end of the Canal, and numerous towns in between.

  4. Bismuth-doped all-fiber mode-locked laser operating at 1340  nm.

    Science.gov (United States)

    Thipparapu, N K; Guo, C; Umnikov, A A; Barua, P; Taranta, A; Sahu, J K

    2017-12-15

    We demonstrate a 1340 nm mode-locked Bismuth (Bi)-doped fiber laser without any saturable absorber. The effect of pump power on pulse width is studied, and a variation from 1.5 to 3 ns is reported. The output of the mode-locked Bi-doped fiber laser is further amplified using a master oscillator power amplifier configuration, and a peak power of 1.15 W is achieved. Soliton bunching is observed, and a true pulse width of 1.2 ps is reported from the measured autocorrelation trace. Stable operation of the mode-locked laser is verified from the radio-frequency spectrum with a fundamental repetition rate of 6.3 MHz, and SNR of 65 dB.

  5. Sub-100 fs single-walled carbon nanotube saturable absorber mode-locked Yb-laser operation near 1 microm.

    Science.gov (United States)

    Schmidt, Andreas; Rivier, Simon; Cho, Won Bae; Yim, Jong Hyuk; Choi, Sun Young; Lee, Soonil; Rotermund, Fabian; Rytz, Daniel; Steinmeyer, Günter; Petrov, Valentin; Griebner, Uwe

    2009-10-26

    Transmission- and reflection-type single-walled carbon nanotube saturable absorbers (SWCNT-SAs) were designed and fabricated for passive mode-locking of bulk lasers in the 1 microm spectral range. Mode-locked laser operation based on a diffusion-bonded Yb:KYW/KYW crystal was demonstrated, and pulses as short as 83 fs and 140 fs were achieved applying reflection-type and transmission-type SWCNT-SA, respectively. The nonlinear parameters of the absorbers were measured to be in close vicinity to those of a semiconductor saturable absorber mirror for the same wavelength range. Mode-locking performance with SWCNT-SAs and the SESAM was compared utilizing the same cavity, with the SESAM resulting in only slightly shorter pulses of 66 fs duration. The nearly identical performance indicates that well-optimized SWCNT-SAs can substitute SESAMs even in the 1 microm region.

  6. Graphene Q-switched mode-locked waveguide laser operating at 1535 nm

    OpenAIRE

    Choudhary, A.; Dhingra, B.D.; Pradeesh, K.; Shepherd, D. P.

    2014-01-01

    A diode-pumped Er,Yb:glass waveguide laser, Q-switched mode-locked using a graphene saturable absorber is presented. Mode-locked pulses at a repetition rate of 6.8 GHz are achieved at an output power of 27 mW and a wavelength of 1535 nm.

  7. Evaluation of hydraulic performance of downstream-controlled Maira-PHLC irrigation canals under crop-based irrigation operations

    NARCIS (Netherlands)

    Munir, S.; Schultz, B.; Suryadi, F.X.; Bharati, L.

    2012-01-01

    Demand-based irrigation systems are operated according to crop water requirements. As crop water requirements remain variable throughout the growing season, the discharges in the canal also vary to meet demands. The irrigation system under study is a demand-based semi-automatic irrigation system,

  8. Current-limiting and recovery characteristics of a flux-lock-type SFCL with two adjustable operational currents

    Science.gov (United States)

    Ko, Seok-Cheol; Han, Tae-Hee; Lim, Sung-Hun

    2014-07-01

    In this research, the current-limiting and recovery characteristics of a flux-lock-type superconducting fault current limiter (SFCL) with two adjustable operational currents were analyzed. The flux-lock-type SFCL with two adjustable operational currents, which consists of two magneticallycoupled coils, two high-TC superconducting (HTSC) modules connected in parallel, and an inserting resistance connected in series with one of the two HTSC modules, can limit the fault current with two operational currents by quench generation in either one HTSC module for a lower fault current or two HTSC modules for a higher fault current directly after the fault occurrence. To verify the current-limiting operation of this type SFCL, we constructed the simulated power distribution system protected by the SFCL, and we executed the short-circuit tests in the fault locations with both the lower and the higher fault currents. Through an analysis of the experimental results, effective current limiting operations of the flux-lock-type SFCL could be confirmed.

  9. 77 FR 57019 - Drawbridge Operation Regulation; Lake Washington Ship Canal, Seattle, WA

    Science.gov (United States)

    2012-09-17

    ... Engineering Hiram M. Chittenden lock immediately upstream or inland of the bridge on the Lake Washington Ship... continue to transit beneath the bridge during this closure period. Due to the nature of work being...

  10. 76 FR 69131 - Drawbridge Operation Regulation; Lake Washington Ship Canal, Seattle, WA

    Science.gov (United States)

    2011-11-08

    ... the closure of the Army Corps of Engineering Hiram M. Chittenden lock immediately upstream or inland... which do not require a bridge opening may continue to transit beneath the bridge during this closure...

  11. Mode-locked operation of Co:MgF(2) and Ni:MgF(2) lasers.

    Science.gov (United States)

    Johnson, B C; Moulton, P F; Mooradian, A

    1984-04-01

    Tunable, mode-locked operation of cw Co:MgF(2) and Ni:MgF(2) lasers has been demonstrated for the first reported time, and autocorrelation measurements of the pulse widths have been made. The Co:MgF(2) system has generated stable pulses over wavelengths from 1.65 to 2.01 microm and has produced pulses as short as 34 psec. The Ni:MgF(2) laser has operated over the 1.61-1.73-microm range, with pulses as short as 23 psec.

  12. Influence of Operator's Experience on the Shaping Ability of Protaper Universal and Waveone Systems: A Comparative Study on Simulated Root Canals.

    Science.gov (United States)

    Troiano, Giuseppe; Dioguardi, Mario; Cocco, Armando; Giannatempo, Giovanni; Laino, Luigi; Ciavarella, Domenico; Berutti, Elio; Lo Muzio, Lorenzo

    2016-01-01

    To assess the influence of operator experience on: shaping and centering ability, mean preparation time and presence of canal aberrations of ProTaper Universal and WaveOne systems on simulated root canals. Sixty S-shaped canals in resin blocks were assigned to four groups (n=15 for each group). Group1 (Experienced operator, ProTaper), Group2 (Experienced operator, WaveOne), Group3 (Inexperienced operator, ProTaper), Group4 (Inexperienced operator, WaveOne). Photographic method was used to record pre- and post-instrumentations images. After superimposition, it has been evaluated presence of canal aberrations and differences in shaping and centering ability between groups. WaveOne system produced a lower amount of canal aberrations both in the hand of expert than inexpert operators. However, a WaveOne instrument breakage occurred in the hands of an inexperienced operator. No differences have been found in the evaluation of shaping ability with both systematics. Operator's experience doesn't influence the shaping ability of ProTaper and WaveOne systems. Experience factor could influence the centering ability in the use of both the systematics. However, WaveOne Primary reduce the mean preparation time and the presence of canal aberrations.

  13. Influence of Operator's Experience on the Shaping Ability of Protaper Universal and Waveone Systems: A Comparative Study on Simulated Root Canals

    Science.gov (United States)

    Troiano, Giuseppe; Dioguardi, Mario; Cocco, Armando; Giannatempo, Giovanni; Laino, Luigi; Ciavarella, Domenico; Berutti, Elio; Lo Muzio, Lorenzo

    2016-01-01

    Objective: To assess the influence of operator experience on: shaping and centering ability, mean preparation time and presence of canal aberrations of ProTaper Universal and WaveOne systems on simulated root canals. Materials and Methods: Sixty S-shaped canals in resin blocks were assigned to four groups (n=15 for each group). Group1 (Experienced operator, ProTaper), Group2 (Experienced operator, WaveOne), Group3 (Inexperienced operator, ProTaper), Group4 (Inexperienced operator, WaveOne). Photographic method was used to record pre- and post-instrumentations images. After superimposition, it has been evaluated presence of canal aberrations and differences in shaping and centering ability between groups. Results: WaveOne system produced a lower amount of canal aberrations both in the hand of expert than inexpert operators. However, a WaveOne instrument breakage occurred in the hands of an inexperienced operator. No differences have been found in the evaluation of shaping ability with both systematics. Operator’s experience doesn't influence the shaping ability of ProTaper and WaveOne systems. Conclusion: Experience factor could influence the centering ability in the use of both the systematics. However, WaveOne Primary reduce the mean preparation time and the presence of canal aberrations. PMID:27843508

  14. Simulation of Ohio River Hydrodynamics to Support Emergency Maintenance Operations on Lock and Dam 52

    Science.gov (United States)

    2015-08-01

    ERDC/CHL CHETN-VII-14 August 2015 Approved for public release; distribution is unlimited. Simulation of Ohio River Hydrodynamics to Support...52 on the Ohio River . The assessment includes an evaluation of the downstream impact of four deflector designs on flow velocities. BACKGROUND: Lock...and Dam 52 is located on the Ohio River approximately 1.5 miles below Brookport, IL. The dam is approximately 2,998 ft in length, with approximately

  15. 75 FR 4693 - Drawbridge Operation Regulation; Inner Harbor Navigational Canal, New Orleans, LA

    Science.gov (United States)

    2010-01-29

    ... Canal, mile 4.6, at New Orleans, LA. The deviation is necessary to ensure the safety of pedestrians as they bike across the bridge for the Ochsner Ironman 70.3 New Orleans event. This deviation allows the... the bridge as part of the 56 mile bike course. Navigation on the waterway consists mainly of tugs with...

  16. 78 FR 45056 - Drawbridge Operation Regulation; Lake Washington Ship Canal, Seattle, WA

    Science.gov (United States)

    2013-07-26

    ... accommodate vehicular traffic attending football games at Husky Stadium at the University of Washington... for Husky Stadium have not yet been determined due to NCAA television scheduling. DATES: This... pre-game and post game football traffic. The Montlake Bridge crosses the Lake Washington Ship Canal at...

  17. Frequency of second mesiobuccal canal in permanent maxillary first molars using the operating microscope and selective dentin removal: A clinical study.

    Science.gov (United States)

    Das, Suroopa; Warhadpande, Manjusha M; Redij, Saurabh A; Jibhkate, N G; Sabir, Husain

    2015-01-01

    The aim of this study was to investigate whether the combination of operating microscope and selective dentin removal increased the frequency of second mesiobuccal (MB2) canal detection in permanent maxillary first molar teeth. One hundred fifty permanent maxillary first molars indicated for root canal treatment were randomly selected from patients belonging to the age group of 18-45 years irrespective of gender. After access cavity preparation and location of main canals, the MB2 canal orifice was sought in all teeth with an endodontic explorer under direct vision (Stage I), then under magnification with the aid of operating microscope (Stage II) and finally with the combined use of operating microscope and selective dentin removal (Stage III). MB2 canals were detected in 36%, 54% and 72% of the teeth in Stages I-III, respectively. This study demonstrated that dental operating microscope when used along with adjunctive aids such as selective dentin removal/troughing and good clinical knowledge will increase the ability of dental clinician to locate MB2 canals.

  18. Frequency of second mesiobuccal canal in permanent maxillary first molars using the operating microscope and selective dentin removal: A clinical study

    Directory of Open Access Journals (Sweden)

    Suroopa Das

    2015-01-01

    Full Text Available Purpose: The aim of this study was to investigate whether the combination of operating microscope and selective dentin removal increased the frequency of second mesiobuccal (MB2 canal detection in permanent maxillary first molar teeth. Materials and Methods: One hundred fifty permanent maxillary first molars indicated for root canal treatment were randomly selected from patients belonging to the age group of 18-45 years irrespective of gender. After access cavity preparation and location of main canals, the MB2 canal orifice was sought in all teeth with an endodontic explorer under direct vision (Stage I, then under magnification with the aid of operating microscope (Stage II and finally with the combined use of operating microscope and selective dentin removal (Stage III. Results: MB2 canals were detected in 36%, 54% and 72% of the teeth in Stages I-III, respectively. Conclusion: This study demonstrated that dental operating microscope when used along with adjunctive aids such as selective dentin removal/troughing and good clinical knowledge will increase the ability of dental clinician to locate MB2 canals.

  19. Frequency of second mesiobuccal canal in permanent maxillary first molars using the operating microscope and selective dentin removal: A clinical study

    Science.gov (United States)

    Das, Suroopa; Warhadpande, Manjusha M.; Redij, Saurabh A.; Jibhkate, N. G.; Sabir, Husain

    2015-01-01

    Purpose: The aim of this study was to investigate whether the combination of operating microscope and selective dentin removal increased the frequency of second mesiobuccal (MB2) canal detection in permanent maxillary first molar teeth. Materials and Methods: One hundred fifty permanent maxillary first molars indicated for root canal treatment were randomly selected from patients belonging to the age group of 18–45 years irrespective of gender. After access cavity preparation and location of main canals, the MB2 canal orifice was sought in all teeth with an endodontic explorer under direct vision (Stage I), then under magnification with the aid of operating microscope (Stage II) and finally with the combined use of operating microscope and selective dentin removal (Stage III). Results: MB2 canals were detected in 36%, 54% and 72% of the teeth in Stages I–III, respectively. Conclusion: This study demonstrated that dental operating microscope when used along with adjunctive aids such as selective dentin removal/troughing and good clinical knowledge will increase the ability of dental clinician to locate MB2 canals. PMID:25684916

  20. Operation of femtosecond Kerr-lens mode-locked Cr:ZnSe lasers with different dispersion compensation methods

    Science.gov (United States)

    Cizmeciyan, M. N.; Cankaya, H.; Kurt, A.; Sennaroglu, A.

    2012-03-01

    We employed various low-cost dispersion compensation methods to generate femtosecond pulses from a Kerr-lens mode-locked (KLM) Cr:ZnSe laser operating near 2400 nm. Prism pairs made of CaF2 and MgF2 and slabs of BK7 and YAG were tested. Pulses as short as 92 fs were obtained when a CaF2 prism pair was used in the resonator with a 1% output coupler. With a 6% output coupler and CaF2 prism pair, pulse energies as high as 1.8 nJ were obtained. The KLM operating point was further analyzed for different dispersion compensation scenarios by using the soliton area theorem to determine the nonlinear refractive index ( n 2) of Cr:ZnSe. Results gave an n 2 value of (1.2±0.2)×10-18 m2/W in agreement with previous reports.

  1. Bidirectional operation of 100 fs bound solitons in an ultra-compact mode-locked fiber laser.

    Science.gov (United States)

    Li, Lei; Ruan, Qiujun; Yang, Runhua; Zhao, Luming; Luo, Zhengqian

    2016-09-05

    We report on the experimental observation of bidirectional 100-fs bound solitons from a nanotube-mode-locked dispersion-managed Er-fiber laser with an ultra-simple linear cavity. Two mode-locked pulse trains in opposite directions are delivered simultaneously from the linear cavity. Under the pump power of <74 mW, both the bidirectional outputs of the laser work at the single-soliton state with pulse duration of 173 fs and 182 fs, respectively. Once the pump power is more than 74 mW, both the bidirectional outputs evolve into the two-soliton bound states with soliton separation of 1.53 ps. Interestingly, the bidirectional operations can show the different bound states, i.e. the forward bound solitons with phase difference of + π/2, and the backward ones with phase difference of -π/2. This is, to the best of our knowledge, the first demonstration of such compact bidirectional soliton fiber laser with the sub-200 fs pulses.

  2. Dual-wavelength synchronous operation of a mode-locked 2-μm Tm:CaYAlO4 laser.

    Science.gov (United States)

    Kong, L C; Qin, Z P; Xie, G Q; Xu, X D; Xu, J; Yuan, P; Qian, L J

    2015-02-01

    We experimentally demonstrated dual-wavelength synchronous operation of a high-power passively mode-locked 2-μm Tm:CaYAlO4 (Tm:CYA) disordered crystal laser with semiconductor saturable absorber mirror (SESAM) as mode locker. The mode-locked laser emitted an average output power as high as 830 mW with pulse duration of 35.3 ps and repetition rate of 145.4 MHz. The mode-locking dual wavelengths were centered at 1958.9 nm and 1960.6 nm, respectively. Autocorrelation trace clearly shows beating pulses with pulse width of 3.5 ps and repetition rate of 0.13 THz.

  3. Focused risk assessment: Mound Plant, Miami-Erie Canal Operable Unit 4

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, D.R.; Dunning, D.F.

    1994-09-29

    In 1969, an underground waste line at Mound Plant ruptured and released plutonium-238 in a dilute nitric acid solution to the surrounding soils. Most of the acid was neutralized by the native soils. The plutonium, which in a neutral solution is tightly sorbed onto clay particles, remained within the spill area. During remediation, a severe storm eroded some of the contaminated soil. Fine grained plutonium-contaminated clay particles were carried away through the natural drainage courses to the remnants of the Miami-Erie Canal adjacent to Mound Plant, and then into the Great Miami River. This focused risk assessment considers exposure pathways relevant to site conditions, including incidental ingestion of contaminated soils, ingestion of drinking water and fish, and inhalation of resuspended soils and sediments. For each potential exposure pathway, a simplified conceptual model and exposure scenarios have been used to develop conservative estimates of potential radiation dose equivalents and health risks. The conservatism of the dose and risk estimates provides a substantive margin of safety in assuring that the public health is protected.

  4. Analysis of C-shaped canal systems in mandibular second molars using surgical operating microscope and cone beam computed tomography: A clinical approach.

    Science.gov (United States)

    Chhabra, Sanjay; Yadav, Seema; Talwar, Sangeeta

    2014-05-01

    The study was aimed to acquire better understanding of C-shaped canal systems in mandibular second molar teeth through a clinical approach using sophisticated techniques such as surgical operating microscope and cone beam computed tomography (CBCT). A total of 42 extracted mandibular second molar teeth with fused roots and longitudinal grooves were collected randomly from native Indian population. Pulp chamber floors of all specimens were examined under surgical operating microscope and classified into four types (Min's method). Subsequently, samples were subjected to CBCT scan after insertion of K-files size #10 or 15 into each canal orifice and evaluated using the cross-sectional and 3-dimensional images in consultation with dental radiologist so as to obtain more accurate results. Minimum distance between the external root surface on the groove and initial file placed in the canal was also measured at different levels and statistically analyzed. Out of 42 teeth, maximum number of samples (15) belonged to Type-II category. A total of 100 files were inserted in 86 orifices of various types of specimens. Evaluation of the CBCT scan images of the teeth revealed that a total of 21 canals were missing completely or partially at different levels. The mean values for the minimum thickness were highest at coronal followed by middle and apical third levels in all the categories. Lowest values were obtained for teeth with Type-III category at all three levels. The present study revealed anatomical variations of C-shaped canal system in mandibular second molars. The prognosis of such complex canal anatomies can be improved by simultaneous employment of modern techniques such as surgical operating microscope and CBCT.

  5. Towards low timing phase noise operation in fiber lasers mode locked by graphene oxide and carbon nanotubes at 1.5 µm.

    Science.gov (United States)

    Wu, Kan; Li, Xiaohui; Wang, Yonggang; Wang, Qi Jie; Shum, Perry Ping; Chen, Jianping

    2015-01-12

    We investigate the timing phase noise of fiber lasers mode locked by graphene oxide (GO) and carbon nanotubes (CNTs), respectively, integrated in a linear cavity fiber laser in the reflecting operation. Due to the shorter decay time of the GO and CNTs, weaker slow saturable absorber effects are expected and mode-locked lasers based on these two saturable absorbers exhibit low excess timing phase noise coupled from the laser intensity noise. Compared with a reference laser mode locked by semiconductor saturable absorber mirror (SESAM), GO based laser obtains a timing phase noise reduction of 7 dB at 1 kHz and a timing jitter reduction of 45% experimentally whereas CNTs based laser obtains a timing phase noise reduction of 3 dB and a timing jitter reduction of 29%. This finding suggests that saturable absorbers with short decay time have the potential for achieving mode locking operation with low timing phase noise, which is important for applications including frequency metrology, high-precision optical sampling, clock distribution and optical sensing.

  6. Exploiting concave-convex linear resonators to design end-pumped solid-state lasers with flexible cavity lengths: Application for exploring the self-mode-locked operation.

    Science.gov (United States)

    Tuan, P H; Chang, C C; Lee, C Y; Cho, C Y; Liang, H C; Chen, Y F

    2016-11-14

    The characteristics of a convex-concave linear resonator under the thermal lensing effect are theoretically analyzed to find an analytical model for designing end-pumped solid-state lasers with flexible cavity lengths. By exploiting the design model, the power scaling for continuous-wave operation under strong thermal lensing can be easily achieved in the proposed resonator with different cavity lengths. Furthermore, the proposed resonator is applied to explore the exclusive influence of cavity length on the self-mode-locked (SML) operation. It is discovered that the lasing longitudinal modes will split into multiple groups in optical spectrum to lead to a multi-pulse mode-locked temporal state when the cavity length increases. Finally, a theoretical model is derived to reconstruct the experimental results of SML operation to deduce a simple relationship between the group number of lasing modes and the cavity length.

  7. 75 FR 29693 - Drawbridge Operation Regulation; Oakland Inner Harbor Tidal Canal, Oakland/Alameda, CA, Schedule...

    Science.gov (United States)

    2010-05-27

    ... ``Document Type'' drop down menu select ``Proposed Rules'' and insert ``USCG-2009-0803'' in the ``Keyword... are technical standards (e.g., specifications of materials, performance, design, or operation; test...

  8. Successful operative management of an upper lumbar spinal canal stenosis resulting in multilevel lower nerve root radiculopathy

    Science.gov (United States)

    McClelland, Shearwood; Kim, Stefan S.

    2015-01-01

    Lumbar stenosis is a common disorder, usually characterized clinically by neurogenic claudication with or without lumbar/sacral radiculopathy corresponding to the level of stenosis. We present a case of lumbar stenosis manifesting as a multilevel radiculopathy inferior to the nerve roots at the level of the stenosis. A 55-year-old gentleman presented with bilateral lower extremity pain with neurogenic claudication in an L5/S1 distribution (posterior thigh, calf, into the foot) concomitant with dorsiflexion and plantarflexion weakness. Imaging revealed grade I spondylolisthesis of L3 on L4 with severe spinal canal stenosis at L3-L4, mild left L4-L5 disc herniation, no stenosis at L5-S1, and no instability. EMG revealed active and chronic L5 and S1 radiculopathy. The patient underwent bilateral L3-L4 hemilaminotomy with left L4-L5 microdiscectomy for treatment of his L3-L4 stenosis. Postoperatively, he exhibited significant improvement in dorsiflexion and plantarflexion. The L5-S1 level was not involved in the operative decompression. Patients with radiculopathy and normal imaging at the level corresponding to the radiculopathy should not be ruled out for operative intervention should they have imaging evidence of lumbar stenosis superior to the expected affected level. PMID:25552866

  9. Successful operative management of an upper lumbar spinal canal stenosis resulting in multilevel lower nerve root radiculopathy

    Directory of Open Access Journals (Sweden)

    Shearwood McClelland

    2015-01-01

    Full Text Available Lumbar stenosis is a common disorder, usually characterized clinically by neurogenic claudication with or without lumbar/sacral radiculopathy corresponding to the level of stenosis. We present a case of lumbar stenosis manifesting as a multilevel radiculopathy inferior to the nerve roots at the level of the stenosis. A 55-year-old gentleman presented with bilateral lower extremity pain with neurogenic claudication in an L5/S1 distribution (posterior thigh, calf, into the foot concomitant with dorsiflexion and plantarflexion weakness. Imaging revealed grade I spondylolisthesis of L3 on L4 with severe spinal canal stenosis at L3-L4, mild left L4-L5 disc herniation, no stenosis at L5-S1, and no instability. EMG revealed active and chronic L5 and S1 radiculopathy. The patient underwent bilateral L3-L4 hemilaminotomy with left L4-L5 microdiscectomy for treatment of his L3-L4 stenosis. Postoperatively, he exhibited significant improvement in dorsiflexion and plantarflexion. The L5-S1 level was not involved in the operative decompression. Patients with radiculopathy and normal imaging at the level corresponding to the radiculopathy should not be ruled out for operative intervention should they have imaging evidence of lumbar stenosis superior to the expected affected level.

  10. 76 FR 14804 - Drawbridge Operation Regulations; Annisquam River and Blynman Canal, Gloucester, MA

    Science.gov (United States)

    2011-03-18

    ... necessary to facilitate a public event, the Yucan One- Mile Road Race, which will cross the SR127 Bridge... a temporary deviation from the regulations to facilitate the Yucan One-Mile Road Race which will... operating regulations is authorized under 33 CFR 117.35. Dated: March 8, 2011. Gary Kassof, Bridge Program...

  11. 76 FR 34145 - Safety Zone, Barrier Testing Operations, Chicago Sanitary and Ship Canal, Romeoville, IL

    Science.gov (United States)

    2011-06-13

    ... approximately 30 miles from Lake Michigan and creates an electric field in the water by pulsing low voltage DC... hazards associated with the U.S. Army Corps of Engineers' simultaneous operation of electric barriers IIA... sound method for preventing and reducing the dispersal of non-indigenous aquatic nuisance species...

  12. All-fiber passively mode-locked Tm-doped NOLM-based oscillator operating at 2-μm in both soliton and noisy-pulse regimes.

    Science.gov (United States)

    Li, Jianfeng; Zhang, Zuxing; Sun, Zhongyuan; Luo, Hongyu; Liu, Yong; Yan, Zhijun; Mou, Chengbo; Zhang, Lin; Turitsyn, Sergei K

    2014-04-07

    A self-starting all-fiber passively mode-locked Tm(3+)-doped fiber laser based on nonlinear loop mirror (NOLM) is demonstrated. Stable soliton pulses centered at 2017.33 nm with 1.56 nm FWHM were produced at a repetition rate of 1.514 MHz with pulse duration of 2.8 ps and pulse energy of 83.8 pJ. As increased pump power, the oscillator can also operate at noise-like (NL) regime. Stable NL pulses with coherence spike width of 341 fs and pulse energy of up to 249.32 nJ was achieved at a center wavelength of 2017.24 nm with 21.33 nm FWHM. To the best of our knowledge, this is the first 2 µm region NOLM-based mode-locked fiber laser operating at two regimes with the highest single pulse energy for NL pulses.

  13. Pre-operative assessment of relationship between inferior dental nerve canal and mandibular impacted third molar in Saudi population

    Directory of Open Access Journals (Sweden)

    S. Shujaat

    2014-07-01

    Conclusions: Our sample population most commonly exhibited horizontally angulated class I position B impactions of the mandible. The position of the ID canal significantly influenced the type of impaction and bone contact.

  14. Pressure locking test results

    Energy Technology Data Exchange (ETDEWEB)

    DeWall, K.G.; Watkins, J.C.; McKellar, M.G.; Bramwell, D. [Idaho National Engineering Lab., Idaho Falls, ID (United States)] [and others

    1996-12-01

    The U.S. Nuclear Regulatory Commission (NRC), Office of Nuclear Regulatory Research, is funding the Idaho National Engineering Laboratory (INEL) in performing research to provide technical input for their use in evaluating responses to Generic Letter 95-07, {open_quotes}Pressure Locking and Thermal Binding of Safety-Related Power-Operated Gate Valves.{close_quotes} Pressure locking and thermal binding are phenomena that make a closed gate valve difficult to open. This paper discusses only the pressure locking phenomenon in a flexible-wedge gate valve; the authors will publish the results of their thermal binding research at a later date. Pressure locking can occur when operating sequences or temperature changes cause the pressure of the fluid in the bonnet (and, in most valves, between the discs) to be higher than the pressure on the upstream and downstream sides of the disc assembly. This high fluid pressure presses the discs against both seats, making the disc assembly harder to unseat than anticipated by the typical design calculations, which generally consider friction at only one of the two disc/seat interfaces. The high pressure of the bonnet fluid also changes the pressure distribution around the disc in a way that can further contribute to the unseating load. If the combined loads associated with pressure locking are very high, the actuator might not have the capacity to open the valve. The results of the NRC/INEL research discussed in this paper show that the relationship between bonnet pressure and pressure locking stem loads appears linear. The results also show that for this valve, seat leakage affects the bonnet pressurization rate when the valve is subjected to thermally induced pressure locking conditions.

  15. Distributed control at Love canal

    Energy Technology Data Exchange (ETDEWEB)

    McPherson, G.; Rider, G.J.; Sadowski, B.; Moore, M.

    1994-09-01

    Love Canal is known worldwide as the site of one of the worst non-nuclear environmental disasters in modern history. For 12 years, a Niagara Falls, New York chemical company used the canal bed as a chemical dump. This article discusses the computerized control of equipment used to remove the toxic materials from the ground under Love Canal, and how the minimization of maintenance is reducing maintenance costs and increasing operator safety.

  16. Locked Out.

    Science.gov (United States)

    Johansson, Veronica; Soekadar, Surjo R; Clausen, Jens

    2017-10-01

    Brain-computer interfaces (BCIs) can enable communication for persons in severe paralysis including locked-in syndrome (LIS); that is, being unable to move or speak while aware. In cases of complete loss of muscle control, termed "complete locked-in syndrome," a BCI may be the only viable solution to restore communication. However, a widespread ignorance regarding quality of life in LIS, current BCIs, and their potential as an assistive technology for persons in LIS, needlessly causes a harmful situation for this cohort. In addition to their medical condition, these persons also face social barriers often perceived as more impairing than their physical condition. Through social exclusion, stigmatization, and frequently being underestimated in their abilities, these persons are being locked out in addition to being locked-in. In this article, we (1) show how persons in LIS are being locked out, including how key issues addressed in the existing literature on ethics, LIS, and BCIs for communication, such as autonomy, quality of life, and advance directives, may reinforce these confinements; (2) show how these practices violate the United Nations Convention on the Rights of Persons with Disabilities, and suggest that we have a moral responsibility to prevent and stop this exclusion; and (3) discuss the role of BCIs for communication as one means to this end and suggest that a novel approach to BCI research is necessary to acknowledge the moral responsibility toward the end users and avoid violating the human rights of persons in LIS.

  17. canal24

    Data.gov (United States)

    California Department of Resources — Canal system center lines in the Central Valley of California and adjacent areas captured from 1:24,000-scale USGS topographic maps. Updates and modifications made...

  18. Prospective case controlled clinical study of post-endodontic pain after rotary root canal preparation performed by a single operator.

    Science.gov (United States)

    Arias, Ana; de la Macorra, José C; Azabal, Magdalena; Hidalgo, Juan J; Peters, Ove A

    2015-03-01

    The aim of this study was to assess the influence of the shaping technique on incidence, intensity, duration and type of postoperative pain (PP). Root canal treatments were carried out with rotary instrumentation (n=80) during a single-visit, and data about pre-treatment conditions were collected. Patients were given a questionnaire to record the presence or absence of post-endodontic pain, its duration and level of discomfort. A matching patient (same pre-treatment conditions but manual instrumentation) was randomly selected from a pool (n = 374) and assigned to the control group. A total of 44 pairs of patients matched completely and were included in the study. Incidence (yes/no) of PP was assessed using Chi-square tests, intensity (mild, moderate, severe) with trend tests and duration (days) with Mann-Whitney U tests. A significantly greater proportion of the patients in the control group reported pain than did patients in the rotary shaping group (p < 0.05). However, pain duration was shorter (p = 0.008) in the control group. Differences in level of discomfort were not statistically significant. The results of this prospective in vivo study suggest that a higher incidence of PP should be expected after manual root canal preparation. However a second major finding of the study is that when present, PP after a rotary canal preparation is expected to last longer. There has been an increase in the use of rotary techniques among dentists in recent years. The present study analyses the differences in the incidence and characteristics of postoperative pain that should be expected after rotary canal preparation compared to traditional manual methods that had not been reported yet. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. A passively mode-locked sub-picosecond Ho3+,Pr3+-doped fluoride fiber laser operating at 2.86 µm(Conference Presentation)

    Science.gov (United States)

    Antipov, Sergei; Jackson, Stuart D.; Withford, Michael J.; Fürbach, Alexander

    2017-03-01

    We demonstrate a passively mode-locked holmium-praseodymium co-doped ring fiber laser that produces an estimated 950 fs pulsewidth and peak power of 4.3 kW at a pulse repetition rate of 74 MHz. The measured center wavelength was 2.86 µm which overlaps more strongly with liquid water whilst better avoiding atmospheric water vapor which overlaps more strongly with previously reported ultrafast Er3+ fiber lasers operating at 2.8. Thus the present system should display better long term stability compared to the Er3+-based system and at the same time, be a more practical tool for interaction with biological tissues. The laser was constructed using a 1.2 m long double-clad fluoride fiber doped with Ho3+ and Pr3+ ions and arranged into a unidirectional ring resonator that was resistant to instabilities associated with back reflections. Two semiconductor 1150 nm laser diodes with the maximum combined output of 7.5 W were used to pump the fiber. Mode-locking was achieved using the combination of two techniques: sub-picosecond pulses were produced by nonlinear polarization evolution after longer pulses were initially obtained using an in-cavity GaAs saturable absorber having a modulation depth of 90% and a relaxation time of 10 ps. A standard arrangement employing two waveplates and an optical isolator was introduced into the resonator to carry out nonlinear polarization rotation. The average power of the mode-locked laser reached 350 mW after the 50% outcoupling mirror. The RF signal-to-noise ratio reached 67 dB for the first peak at the resolution bandwidth of 10 kHz.

  20. The influence of the surgical operating microscope in locating the mesiolingual canal orifice: a laboratory analysis Influência do microscópio cirúrgico na localização do canal mesiopalatino: uma análise laboratorial

    Directory of Open Access Journals (Sweden)

    Tauby Coutinho Filho

    2006-03-01

    Full Text Available The aim of this study was to evaluate the influence of using the surgical operating microscope (SOM for detection of the mesiolingual (ML canal orifice in extracted first maxillary permanent molars. One hundred and eight human first maxillary permanent molars were randomly selected and mounted onto a dental chair mannequin. Conventional access cavity was prepared and an attempt was made to locate the mesiolingual canal orifice using only a sharp explorer, a mirror and a #10 K-file. A mesiolingual canal orifice was either located or not located. If not located, the teeth were then evaluated by using a surgical operating microscope (SOM. The mesiobuccal roots of all teeth where the ML canal orifice had not been located were sectioned in an axial plane and the sections were explored with an adjunctive use of the SOM at a 25 X magnification. ML canal orifices were detected in 58 teeth using only a sharp explorer, a mirror and #10 K-file. In the remaining 50 teeth, 37 ML canal orifices were located by using the SOM and 3 ML canal orifices were located after root sectioning. In 10 teeth, the ML canal orifices were not found. The results of this study showed a high incidence of a ML canal in the mesiobuccal roots of the first maxillary molars (90.7% and demonstrated that the adjunctive use of the SOM increased the ability of the dental clinician to locate the ML canal orifice.O objetivo deste estudo foi avaliar a influência do uso do microscópio cirúrgico na localização do canal mesiopalatino (MP em primeiros molares superiores humanos permanentes extraídos. Cento e oito primeiros molares superiores permanentes foram selecionados aleatoriamente e montados em um manequim dental. Uma cavidade de acesso convencional foi realizada e uma tentativa de se localizar o canal mesiopalatino foi feita, utilizando-se somente uma sonda exploradora afiada, um odontoscópio e uma lima tipo K tamanho 10. Quando não localizado o referido canal, os dentes foram

  1. The Effect of the Dental Operating Microscope on the Outcome of Nonsurgical Root Canal Treatment: A Retrospective Case-control Study.

    Science.gov (United States)

    Khalighinejad, Navid; Aminoshariae, Anita; Kulild, James C; Williams, Kristin A; Wang, Jeannie; Mickel, Andre

    2017-05-01

    The aim of the current investigation was to assess the effect of the use of a dental operating microscope on the outcome of nonsurgical root canal treatment (NS RCT) while treating the mesiobuccal (MB) root of the maxillary first molar. This retrospective investigation included endodontically treated maxillary first molars (ETMs) with apparent adequate previous NS RCT and restorations referred for endodontic retreatment at the endodontic graduate clinic. Inclusion criteria were ETMs that were diagnosed with irreversible pulpitis and normal periapical tissues before the initial NS RCT and ETMs that presented with a minimum of 1 identifiable periapical lesion (PAR) at 1 of the roots at the time of retreatment. One hundred ninety-five ETMs were included and divided into 2 groups: (1) the initial NS RCT had been performed using a microscope (n = 83) and (2) NS RCT had been performed without the use of a microscope (n = 112). Data extracted were whether the second MB (MB2) canal was located initially and the presence of an MB PAR at the time of retreatment. Data were statistically analyzed using binary logistic regression (α = 0.05). The MB root was 3 times more likely to present with a PAR at the time of retreatment if the initial NS RCT was performed without the use of a microscope (P microscope (P microscope, a missed MB2 canal was not associated with the presence of an MB PAR. With proper education, dentists can gain further insight into recognizing limitations in treating cases that require advanced training and advanced optics such as a microscope. Based on this strategy, it would appear that the outcome of NS RCT can be improved. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  2. Boolean Logic Tree of Label-Free Dual-Signal Electrochemical Aptasensor System for Biosensing, Three-State Logic Computation, and Keypad Lock Security Operation.

    Science.gov (United States)

    Lu, Jiao Yang; Zhang, Xin Xing; Huang, Wei Tao; Zhu, Qiu Yan; Ding, Xue Zhi; Xia, Li Qiu; Luo, Hong Qun; Li, Nian Bing

    2017-09-19

    The most serious and yet unsolved problems of molecular logic computing consist in how to connect molecular events in complex systems into a usable device with specific functions and how to selectively control branchy logic processes from the cascading logic systems. This report demonstrates that a Boolean logic tree is utilized to organize and connect "plug and play" chemical events DNA, nanomaterials, organic dye, biomolecule, and denaturant for developing the dual-signal electrochemical evolution aptasensor system with good resettability for amplification detection of thrombin, controllable and selectable three-state logic computation, and keypad lock security operation. The aptasensor system combines the merits of DNA-functionalized nanoamplification architecture and simple dual-signal electroactive dye brilliant cresyl blue for sensitive and selective detection of thrombin with a wide linear response range of 0.02-100 nM and a detection limit of 1.92 pM. By using these aforementioned chemical events as inputs and the differential pulse voltammetry current changes at different voltages as dual outputs, a resettable three-input biomolecular keypad lock based on sequential logic is established. Moreover, the first example of controllable and selectable three-state molecular logic computation with active-high and active-low logic functions can be implemented and allows the output ports to assume a high impediment or nothing (Z) state in addition to the 0 and 1 logic levels, effectively controlling subsequent branchy logic computation processes. Our approach is helpful in developing the advanced controllable and selectable logic computing and sensing system in large-scale integration circuits for application in biomedical engineering, intelligent sensing, and control.

  3. 49 CFR 236.775 - Movement, switch-and-lock.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Movement, switch-and-lock. 236.775 Section 236.775... Movement, switch-and-lock. A device, the complete operation of which performs the three functions of unlocking, operating and locking a switch, movable-point frog or derail. ...

  4. Single-frequency operation of a broad-area laser diode by injection locking of a complex spatial mode via a double phase conjugate mirror

    NARCIS (Netherlands)

    van Voorst, P.D.; Offerhaus, Herman L.; Boller, Klaus J.

    2006-01-01

    We demonstrate what is believed to be the first phase-coherent locking of a high-power broad-area diode to a single-frequency master laser. We use photorefractive double phase conjugation to lock the diode in a selfoptimized complex spatial mode while the photorefractive crystal diffracts that

  5. Lost Treasures: Locks

    Directory of Open Access Journals (Sweden)

    Semra SARAÇOĞLU ÇELİK

    2015-03-01

    Full Text Available Locks have been widely used in our daily life. In this paper an attempt is made to study the history of locks and to give the kinds of locks and samples from past to present: Ancient Egypt, Chinese, Iran, Roman, Turk-Islam Locks. Ancient locks relied on the pin tumbler principle that many of today's locks use. Many early Roman Keys were made to be worn as rings, because clothing of Romans did not have pockets. It is hoped that this article can simulate more research and publications regarding the development of ancient locks.

  6. Phase Locking of CO(2) Lasers.

    Science.gov (United States)

    Weingartner, W; Schröder, K; Schuöcker, D

    2001-05-20

    A method of phase locking two CO(2) lasers by radiation exchange is presented. This phase-locking was achieved by use of a copper prism as a beam folding device in the resonators and extraction of the output radiation by a common output coupler. Energy exchange led to a phase-locked state if several locking conditions were fulfilled. The amount of radiation injected from one resonator to the second cavity could be adjusted by movement of the prism. The influence of the strength of coupling on the locking range was studied. The beat signal between the two unlocked lasers could be measured, whereas in the case of phase-locked operation twice the intensity was detected. Despite the inclusion of several assumptions, a simplified mathematical model delivered good agreement between calculated and experimental results.

  7. Tunable single-longitudinal-mode operation of an injection-locked TEA CO2 laser. [ozone absorption spectroscopy

    Science.gov (United States)

    Megie, G.; Menzies, R. T.

    1979-01-01

    The tunable single-longitudinal-mode operation of a TEA CO2 laser by an injection technique using a CW waveguide laser as the master oscillator is reported. With the experimental arrangement described, in which the waveguide laser frequency is tuned to correspond to one of the oscillating longitudinal modes of the TEA laser, single-longitudinal-mode operation was achieved with no apparent reduction in the TEA output energy, on various CO2 lines with frequency offsets from the line center as large as 300 MHz. The capability of this technique for high-resolution spectroscopy or atmospheric lidar studies is demonstrated by the recording of the absorption spectrum of a strong ozone line.

  8. Highly efficient and robust operation of Kerr-lens mode-locked Cr:LiSAF lasers using gain-matched output couplers.

    Science.gov (United States)

    Canbaz, Ferda; Beyatli, Ersen; Chen, Li-Jin; Sennaroglu, Alphan; Kärtner, Franz X; Demirbas, Umit

    2014-01-15

    We present efficient and robust Kerr-lens mode locking (KLM) of a diode-pumped Cr:LiSAF laser using a gain-matched output coupler (GMOC). An inexpensive, battery-powered 660 nm single-spatial-mode diode was used as the pump source. GMOC enhances the effective self-amplitude modulation depth by reducing the gain-filtering effect in broadband KLM operation to provide significant improvement in efficiency and robustness. Pulsing can be initiated without careful cavity alignment and is sustained for hours. 13 fs pulses with an average power of 25 mW have been generated using only 120 mW of pump power. The corresponding pulse energy and peak power is 200 pJ and 15 kW for the 126 MHz repetition rate cavity. Optical-to-optical conversion efficiency of the system is 21%, which represents an order of magnitude improvement in reported efficiencies for such diode-pumped ultrashort-pulse KLM Cr:LiSAF lasers. The obtainable pulse width is currently limited by the dispersion bandwidth of the available optics and can be potentially reduced to below 7 fs.

  9. A Wide-Band CMOS Injection Locked Frequency Divider

    NARCIS (Netherlands)

    Acar, M.; Leenaerts, Domine; Nauta, Bram

    In this paper we propose a novel inductorless injection-locked frequency divider (ILFD) that can make divisions with ratios 2,4,6 and 8 with wide locking ranges. Fabricated in a digital 0.18 μm CMOS process the divider can operate up to 15 GHz. The measured locking ranges of the divider for division

  10. Lock-free dynamic hash tables with open addressing

    NARCIS (Netherlands)

    Gao, H.; Groote, J.F.; Hesselink, W.H.

    We present an efficient lock-free algorithm for parallel accessible hash tables with open addressing, which promises more robust performance and reliability than conventional lock-based implementations. “Lock-free” means that it is guaranteed that always at least one process completes its operation

  11. Mode-locking operation of synchronously-pumped KCl:Tl{sup 0}(1) laser; Operacao do laser de KCl:Tl{sub 0}(1) no regime de travamento de modos por bombeamento sincrono

    Energy Technology Data Exchange (ETDEWEB)

    Freitas, Anderson Zanardi de

    1997-07-01

    It is described the mode locking and c.w. operation of a Nd:YAG pumped KCl:Tl{sup 0}(1) color center laser operation. The operation conditions in both modes were studied and the main parameters could be determined. The Tl{sup 0}(1) color center production were optimized, by measuring the Tl{sup 0}(1) optical absorption during the photoconversion process. The Nd:YAG pump laser was optimized by designing the optical resonator considering the thermal lens and the mode filling of the rod; that provided 10 W of output power. In the active mode locking regime, pulses with 80 ps of duration and 6,5 W of output power were obtained. In the c.w. regime of operation, the KCl:Tl{sup 0}(1) color center laser produced 40 mW of output power, at 1,5 {mu}m. The laser main parameters (gain and losses) could be determined and were compared with the theoretical ones, showing good agreement. It was also verified the importance of the water vapor pressure in the atmospheric path inside the laser resonator, that introduces significant losses. In the made locking regime, 17 ps pulse duration were obtained and 6 mW of output power, and this limited result are mostly due to the low value of Tl{sup 0}(1) center concentration. (author)

  12. Locking mechanism for orthopedic braces

    Science.gov (United States)

    Chao, J. I.; Epps, C. H., Jr.

    1981-01-01

    An orthopedic brace locking mechanism is described which under standing or walking conditions cannot be unlocked, however under sitting conditions the mechanism can be simply unlocked so as to permit bending of the patient's knee. Other features of the device include: (1) the mechanism is rendered operable, and inoperable, dependent upon the relative inclination of the brace with respect to the ground; (2) the mechanism is automatically locked under standing or walking conditions and is manually unlocked under sitting conditions; and (3) the mechanism is light in weight and is relatively small in size.

  13. 33 CFR 117.438 - Company Canal.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Company Canal. 117.438 Section 117.438 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.438 Company Canal. (a) The draw of the...

  14. The role of stenosis ratio as a predictor of surgical satisfaction in patients with lumbar spinal canal stenosis: a receiver-operator characteristic (ROC) curve analysis.

    Science.gov (United States)

    Mohammadi, Hassanreza R; Azimi, Parisa; Benzel, Edward C; Shahzadi, Sohrab; Azhari, Shirzad

    2016-09-01

    The aim of this study was to elucidate independent factors that predict surgical satisfaction in lumbar spinal canal stenosis (LSCS) patients. Patients who underwent surgery were grouped based on the age, gender, duration of symptoms, walking distance, Neurogenic Claudication Outcome Score (NCOS) and the stenosis ratio (SR) described by Lurencin. We recorded on 2-year patient satisfaction using standardized measure. The optimal cut-off points in SR, NCOS and walking distance for predicting surgical satisfaction were estimated from sensitivity and specificity calculations and receiver operator characteristic (ROC) curves. One hundred fifty consecutive patients (51 male, 99 female, mean age 62.4±10.9 years) were followed up for 34±13 months (range 24-49). One, two, three and four level stenosis was observed in 10.7%, 39.3%, 36.0 % and 14.0% of patients, respectively. Post-surgical satisfaction was 78.5% at the 2 years follow up. In ROC curve analysis, the asymptotic significance is less than 0.05 in SR and the optimal cut-off value of SR to predict worsening surgical satisfaction was measured as more than 0.52, with 85.4% sensitivity and 77.4% specificity (AUC 0.798, 95% CI 0.73-0.90; Ppatients with degenerative lumbar stenosis considered for surgical treatment. Using a ROC curve analysis, a radiological feature, the SR, demonstrated superiority in predicting patient satisfaction, compared to functional and clinical characteristics such as walking distance and NCOS.

  15. Post-operative Pain Analysis between Single Visit and Two Visit Root Canal Treatments using Visual Analogue Scale: An In Vivo Study

    Directory of Open Access Journals (Sweden)

    Kavita Tarale

    2013-01-01

    Full Text Available The purpose of this clinical study was to evaluate post-operative pain, after root canal therapy, performed in one appointment versus two appointment using calcium hydroxide intracanal medicament. Study design: In this in-vivo study, 60 patients requiring root canal therapy on permanent 1st molars were included. Patients were randomly divided into two experimental and one control group. Group1: One visit therapy (n=20 Group2: Two visit therapy with 1 week of calcium hydroxide dressing (n=20 Group3(Control: Two visit therapy with 1 week of sterile dry cotton pellet dressing (n=20 Materials and method : The standard protocol for all the patients included local anaesthesia, isolation & access cavity preparation, chemomechanical preparation with Rotary Protaper NiTi instruments, and irrigation with 3% sodium hypochlorite, 17% EDTA, 0.9%saline and 2% chlorhexidine. Teeth in group1 (n=20 were obturated on the same appointment using single cone technique (6% gutta percha points and AH Plus sealer. Teeth in group 2(n=20 and group 3(n=20 were given a dressing of calcium hydroxide and dry cotton pellet respectively for a week followed by double seal with Cavit G and IRM. These teeth were obturated on the 2nd appointment using same material and techniques as in group 1. Teeth in all three groups were restored with dual cure composite resin. A modified Visual Analogue Scale was used to measure preoperative pain and postoperative pain after 6, 12, 24 & 48hrs interval. Statistical analysis was performed using an independent-sample t test. There was no statistically significant difference between groups at any of the four postoperative intervals. There was no significant difference among all the three groups studied after 12, 24hrs & 48hrs. Conclusion : Within the limitations of this in vivo study, it may be concluded that Single Visit Endodontics provides excellent results, if care in diagnosis and proper case selection is given importance. Calcium hydroxide

  16. Overview of locking systems

    Energy Technology Data Exchange (ETDEWEB)

    Gee, K.T.; Scott, S.H.; Wilde, M.G. [Sandia National Labs., Albuquerque, NM (United States); Highland, S.E. [Albuquerque Safe Co., Albuquerque, NM (United States)

    1993-12-01

    The purpose of this document is to present technical information that should be useful for understanding and applying locking systems for physical protection and control. There are major sections on hardware for locks, vaults, safes, and security containers. Other topics include management of lock systems and safety considerations. This document also contains notes on standards and specifications and a glossary.

  17. Orthogonally dual-polarization passively mode-locking operation of Nd:La0.25Gd0.75VO4 crystal

    Science.gov (United States)

    Xu, Honghao; Tang, Dingyuan; Yu, Haohai; Zhang, Huaijin; Wang, Jiyang

    2016-11-01

    We demonstrated in an a-cut Nd:La0.25Gd0.75VO4 mixed crystal the passively mode locking laser of two different wavelengths in orthogonal polarization states with a semiconductor saturable absorber mirror (SESAM). Due to the special anisotropic gain feature of the mixed crystal, through careful controlling on the cavity loss anisotropy, the simultaneous orthogonal polarization states laser were also achieved. In σ polarization states, the pulse width of 2.2 ps was close to the shortest pulse width obtained with Nd-doped vanadate crystal to my knowledge. What's more, dual-wavelength synchronized mode locking and bound-soliton-like pulse mode locking was also experimentally observed.

  18. 77 FR 22492 - Drawbridge Operation Regulations; Long Island, New York Inland Waterway from East Rockaway Inlet...

    Science.gov (United States)

    2012-04-16

    ..., shafts, couplings, bearings, lubrication lines, span lock motors, span lock reducers, span lock guides... standards are technical standards (e.g., specifications of materials, performance, design, or operation...

  19. Atrioventricular Canal Defect

    Science.gov (United States)

    ... tract infections. Atrioventricular canal defect can cause recurrent bouts of lung infections. Heart failure. Untreated, atrioventricular canal ... Leaky heart valves Narrowing of the heart valves Abnormal heart rhythm Breathing difficulties associated with lung damage ...

  20. El Canal del Atazar I

    Directory of Open Access Journals (Sweden)

    López de Berges y de los Santos, Emilio

    1967-03-01

    Full Text Available The Atazar Canal helps to supply Madrid with water, from the rivers Lozoya, Jarama and Sorbe. The section which operates at present starts at the Torrelaguna dam and finishes at the El Goloso reservoir. Later a further section will be added, from the Atazar dam, on the Lozoya river, to link up with the control dam at Torrelaguna. The canal capacity is 16 m3/sec, and it is 43.47 km long. It has a slope of 4/10.000. The cross section is similar to that of the Jarama canal, already built. There are interconnections between this canal and the Canal Alto, which previously supplied the high and medium part of Madrid. To overcome the ground unevenness 5 syphons have been built, the most important of which is the Colmenar Goloso syphon, which is 10.88 km in length. Construction commenced on December 10, 1962, and water reached Madrid on June 15th, 1966. The initial budget for this project was 1,500 million pesetas.El canal del Atazar refuerza considerablemente el abastecimiento de aguas a Madrid, procedentes de los ríos Lozoya, Jarama y, en un próximo futuro, del Sorbe. El tramo, actualmente en funcionamiento, empieza en el salto de Torrelaguna y finaliza en los depósitos de El Goloso. Más adelante se completará su trazado mediante un nuevo tramo que partirá del embalse de Atazar, en el Lozoya, para unirse al actual en el depósito regulador de Torrelaguna. Su capacidad es de 16 m3/s; su longitud, 43,471 km, y su pendiente, 4 diezmilésimas. La sección tipo es análoga a la del canal del Jarama, de construcción anterior. Mediante la oportuna obra de transvase se realizan intercambios entre este Canal y el Canal Alto que abastecía anteriormente la parte media y alta de la capital. Para salvar los desniveles del terreno se han construido 5 sifones, siendo el más importante el de Colmenar-Goloso, con una longitud de 10,8S4 km. El comienzo de las obras tuvo lugar el 10 de diciembre de 1962, y el agua llegó a Madrid el 15 de junio de 1966. Su

  1. Correlations between locked modes and impurity influxes

    Energy Technology Data Exchange (ETDEWEB)

    Fishpool, G.M. [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Lawson, K.D. [UKAEA Culham Lab., Abingdon (United Kingdom)

    1994-07-01

    An analysis of pulses that were disturbed by medium Z impurity influxes (Cl, Cr, Fe and Ni) recorded during the 91/92 JET operations, has demonstrated that such influxes can result in MHD modes which subsequently ``lock``. A correlation is found between the power radiated by the influx and the time difference between the start of the influx and the beginning of the locked mode. The growth in the amplitude of the locked mode itself can lead to further impurity influxes. A correlation is noted between intense influxes (superior to 10 MW) and the mode ``unlocking``. (authors). 4 refs., 4 figs.

  2. 1st-Stokes and 2nd-Stokes dual-wavelength operation and mode-locking modulation in diode-side-pumped Nd:YAG/BaWO4 Raman laser.

    Science.gov (United States)

    Shen, Hongbin; Wang, Qingpu; Zhang, Xingyu; Chen, Xiaohan; Cong, Zhenhua; Wu, Zhenguo; Bai, Fen; Lan, Weixia; Gao, Liang

    2012-07-30

    1st-Stokes and 2nd-Stokes dual-wavelength operation within a diode-side-pumped Q-switched Nd:YAG/BaWO(4) intracavity Raman laser was realized. Using an output coupler of transmission of 3.9% at 1180 nm and transmission of 60.08% at 1325 nm, the maximum output power of 8.30 W and 2.84 W at a pulse repetition rate of 15 kHz for the 1st Stokes and the 2nd Stokes laser were obtained, respectively. The corresponding optical conversion efficiency from diode laser to the 1st Stokes and 2nd Stokes laser are 5.0% and 1.4%, respectively. With the pump power of 209 W and a pulse repetition rate of 15 kHz, the 1st Stokes and the 2nd Stokes pulse widths were 20.5 ns and 5.8 ns, respectively. The stable simultaneous Q-switching and mode locking of the 2nd Stokes laser without mode locking component was obtained at the pump power of about 29~82 W. The estimated mode-locked pulse width was approximately 31 ps at the pump power of 50 W and a pulse repetition rate of 15 kHz.

  3. MAXILLARY FIRST PREMOLARS WITH THREE ROOT CANALS: TWO CASE REPORTS

    Directory of Open Access Journals (Sweden)

    Zeliha UĞUR

    2017-10-01

    Full Text Available It is very important that the dentists have sufficient information about possible variations in the expected root canal configurations in order to achieve success in endodontic treatment. In addition to having adequate knowledge on the variations of the root canal anatomy, periapical radiographs from different angles, careful examination of the pulp chamber floor, and use of dental operation microscope during the procedure are also important factors that contribute to the diagnosis of the additional roots and canals. The aims of this article are to present the diagnostic approach and root canal treatments of two maxillary first premolar teeth with three canals in two patients.

  4. Management of grossly destroyed endodontically treated teeth with lock and key custom modified cast post and core design: A case series

    Directory of Open Access Journals (Sweden)

    E Deenadayalan

    2015-01-01

    Full Text Available The purpose of this paper is to demonstrate a more retentive custom modified lock and key design of metal cast post and core for the restoration of grossly destroyed endodontically treated molar tooth. The lock and key metal cast post consists of two parts, one in the distal canal (primary post and the other one in mesio-lingual canal (secondary post. The primary post has a lock design, while the secondary post contains the key design, both of which interlock together. Lock and key cast post, mentioned in this report can be an effective design for the management of grossly destroyed molar teeth.

  5. Management of grossly destroyed endodontically treated teeth with lock and key custom modified cast post and core design: A case series.

    Science.gov (United States)

    Deenadayalan, E; Kumar, Ashok; Tewari, Rajendra Kumar; Mishra, Surendra Kumar; Alam, Sharique

    2015-01-01

    The purpose of this paper is to demonstrate a more retentive custom modified lock and key design of metal cast post and core for the restoration of grossly destroyed endodontically treated molar tooth. The lock and key metal cast post consists of two parts, one in the distal canal (primary post) and the other one in mesio-lingual canal (secondary post). The primary post has a lock design, while the secondary post contains the key design, both of which interlock together. Lock and key cast post, mentioned in this report can be an effective design for the management of grossly destroyed molar teeth.

  6. Locke (adversaires de)

    DEFF Research Database (Denmark)

    Schøsler, Jørn

    2017-01-01

    den apologetiske kritik af John Locke i den franske modoplysning centreret om 'medødte idéer' og den 'tænkende materie'.......den apologetiske kritik af John Locke i den franske modoplysning centreret om 'medødte idéer' og den 'tænkende materie'....

  7. Holberg, lecteur de Locke

    DEFF Research Database (Denmark)

    Schøsler, Jørn

    2009-01-01

      En undersøgelse af John Lockes modtagelse i dansk Oplysningsfilosofi med særligt henblik på Holberg......  En undersøgelse af John Lockes modtagelse i dansk Oplysningsfilosofi med særligt henblik på Holberg...

  8. Locke on measurement.

    Science.gov (United States)

    Anstey, Peter R

    2016-12-01

    Like many virtuosi in his day, the English philosopher John Locke maintained an active interest in metrology. Yet for Locke, this was no mere hobby: questions concerning measurement were also implicated in his ongoing philosophical project to develop an account of human understanding. This paper follows Locke's treatment of four problems of measurement from the early Drafts A and B of the Essay concerning Human Understanding to the publication of this famous book and its aftermath. It traces Locke's attempt to develop a natural or universal standard for the measure of length, his attempts to grapple with the measurement of duration, as well as the problems of determining comparative measures for secondary qualities, and the problem of discriminating small differences in the conventional measures of his day. It is argued that the salient context for Locke's treatment of these problems is the new experimental philosophy and its method of experimental natural history. Copyright © 2016. Published by Elsevier Ltd.

  9. Jaw locking after maxillofacial trauma

    Directory of Open Access Journals (Sweden)

    David B. Kamadjaja

    2007-09-01

    Full Text Available The purpose of this report is to present two cases of jaw locking with two different etiologies. In case #1, jaw locking occured 5.5 months after a surgical reduction and internal fixation on the fractured maxilla and mandible. Some plain radiographic x-ray were made but failed to give adequate information in establishing the cause of trismus. The three dimensional computed tomography (3D-CT was finally made and able to help guide the pre-operative diagnosis and treatment. Two-steps gap arthroplasty were done comprising a gap arthroplasty leading to acceptable outcome. An adult patient in case #2 with a history of trauma at his childhood and bird-like face apprearance clinically, was unable to open the mouth since the time of accident. The patient was diagnosed with bilateral ankylosis of temporomandibular joints. One side (right gap arthroplasty was done and resulted in normal mouth opening.

  10. Self-mode-locking semiconductor disk laser.

    Science.gov (United States)

    Gaafar, Mahmoud; Richter, Philipp; Keskin, Hakan; Möller, Christoph; Wichmann, Matthias; Stolz, Wolfgang; Rahimi-Iman, Arash; Koch, Martin

    2014-11-17

    The development of mode-locked semiconductor disk lasers received striking attention in the last 14 years and there is still a vast potential of such pulsed lasers to be explored and exploited. While for more than one decade pulsed operation was strongly linked to the employment of a saturable absorber, self-mode-locking emerged recently as an effective and novel technique in this field - giving prospect to a reduced complexity and improved cost-efficiency of such lasers. In this work, we highlight recent achievements regarding self-mode-locked semiconductor devices. It is worth to note, that although nonlinear effects in the active medium are expected to give rise to self-mode-locking, this has to be investigated with care in future experiments. However, there is a controversy whether results presented with respect to self-mode-locking truly show mode-locking. Such concerns are addressed in this work and we provide a clear evidence of mode-locking in a saturable-absorber-free device. By using a BBO crystal outside the cavity, green light originating from second-harmonic generation using the out-coupled laser beam is demonstrated. In addition, long-time-span pulse trains as well as radiofrequency-spectra measurements are presented for our sub-ps pulses at 500 MHz repetition rate which indicate the stable pulse operation of our device. Furthermore, a long-time-span autocorrelation trace is introduced which clearly shows absence of a pedestal or double pulses. Eventually, a beam-profile measurement reveals the excellent beam quality of our device with an M-square factor of less than 1.1 for both axes, showing that self-mode-locking can be achieved for the fundamental transverse mode.

  11. Bicycle Parking and Locking

    DEFF Research Database (Denmark)

    Larsen, Jonas

    2017-01-01

    Cars, trains, and bicycles are designed to be on the move. Mobilities studies have theorized and analyzed these modes of transport as powerful entities slicing through, and speeding-up, cities. Yet they also stand still, being parked and locked, immobilized and secured, until their next trip....... This article contributes with new insights into parking and locking - ‘moorings’ - to cycling literature. It presents an ethnography of ‘design moorings’ and practices associated with parking and locking bikes. The main case study is the very pro-cycling city of Copenhagen. Yet to explore what is unique about...

  12. Extended Lock Range Zero-Crossing Digital Phase-Locked Loop with Time Delay

    Directory of Open Access Journals (Sweden)

    Nasir Qassim

    2005-01-01

    Full Text Available The input frequency limit of the conventional zero-crossing digital phase-locked loop (ZCDPLL is due to the operating time of the digital circuitry inside the feedback loop. A solution that has been previously suggested is the introduction of a time delay in the feedback path of the loop to allow the digital circuits to complete their sample processing before the next sample is received. However, this added delay will limit the stable operation range and hence lock range of the loop. The objective of this work is to extend the lock range of ZCDPLL with time delay by using a chaos control. The tendency of the loop to diverge is measured and fed back as a form of linear stabilization. The lock range extension has been confirmed through the use of a bifurcation diagram, and Lyapunov exponent.

  13. LOCKS AND KEYS SERVICE

    CERN Multimedia

    Locks and Keys Service

    2002-01-01

    The Locks and Keys service (ST/FM) will move from building 55 to building 570 from the 2nd August to the 9th August 2002 included. During this period the service will be closed. Only in case of extreme urgency please call the 164550. Starting from Monday, 12th August, the Locks and Keys Service will continue to follow the activities related to office keys (keys and locks) and will provide the keys for furniture. The service is open from 8h30 to 12h00 and from 13h00 to 17h30. We remind you that your divisional correspondents can help you in the execution of the procedures. We thank you for your comprehension and we remain at your service to help you in solving all the matters related to keys for offices and furniture. Locks and Keys Service - ST Division - FM Group

  14. An efficient locking model for concurrency control in OODBS

    Directory of Open Access Journals (Sweden)

    G Arumugam

    2006-01-01

    Full Text Available When several transactions execute concurrently in a database, the isolation property may no longer be preserved. It is necessary for the system to control the interaction among the concurrent transactions. This paper presents a new locking model for concurrency control in object oriented database systems. This model is motivated by a desire to provide high concurrency and low locking overheads in accessing objects. The proposed model consists of a rich set of lock modes, hash table, lock-based signatures and B+ trees. The performance study result shows that the proposed model performs well for all possible operations on objects.

  15. The Real Performance Drivers behind XML Lock Protocols

    Science.gov (United States)

    Bächle, Sebastian; Härder, Theo

    Fine-grained lock protocols should allow for highly concurrent transaction processing on XML document trees, which is addressed by the taDOM lock protocol family enabling specific lock modes and lock granules adjusted to the various XML processing models. We have already proved its operational flexibility and performance superiority when compared to competitor protocols. Here, we outline our experiences gained during the implementation and optimization of these protocols. We figure out their performance drivers to maximize throughput while keeping the response times at an acceptable level and perfectly exploiting the advantages of our tailor-made lock protocols for XML trees. Because we have implemented all options and alternatives in our prototype system XTC, benchmark runs for all “drivers” allow for comparisons in identical environments and illustrate the benefit of all implementation decisions. Finally, they reveal that careful lock protocol optimization pays off.

  16. Experimental quantum data locking

    Science.gov (United States)

    Liu, Yang; Cao, Zhu; Wu, Cheng; Fukuda, Daiji; You, Lixing; Zhong, Jiaqiang; Numata, Takayuki; Chen, Sijing; Zhang, Weijun; Shi, Sheng-Cai; Lu, Chao-Yang; Wang, Zhen; Ma, Xiongfeng; Fan, Jingyun; Zhang, Qiang; Pan, Jian-Wei

    2016-08-01

    Classical correlation can be locked via quantum means: quantum data locking. With a short secret key, one can lock an exponentially large amount of information in order to make it inaccessible to unauthorized users without the key. Quantum data locking presents a resource-efficient alternative to one-time pad encryption which requires a key no shorter than the message. We report experimental demonstrations of a quantum data locking scheme originally proposed by D. P. DiVincenzo et al. [Phys. Rev. Lett. 92, 067902 (2004), 10.1103/PhysRevLett.92.067902] and a loss-tolerant scheme developed by O. Fawzi et al. [J. ACM 60, 44 (2013), 10.1145/2518131]. We observe that the unlocked amount of information is larger than the key size in both experiments, exhibiting strong violation of the incremental proportionality property of classical information theory. As an application example, we show the successful transmission of a photo over a lossy channel with quantum data (un)locking and error correction.

  17. Locke and botany.

    Science.gov (United States)

    Anstey, Peter R; Harris, Stephen A

    2006-06-01

    This paper argues that the English philosopher John Locke, who has normally been thought to have had only an amateurish interest in botany, was far more involved in the botanical science of his day than has previously been known. Through the presentation of new evidence deriving from Locke's own herbarium, his manuscript notes, journal and correspondence, it is established that Locke made a modest contribution to early modern botany. It is shown that Locke had close and ongoing relations with the Bobarts, keepers of the Oxford Botanic Garden, and that Locke distributed seeds and plant parts to other botanists, seeds of which the progeny almost certainly ended up in the most important herbaria of the period. Furthermore, it is claimed that the depth of Locke's interest in and practice of botany has a direct bearing on our understanding of his views on the correct method of natural philosophy and on the interpretation of his well known discussion of the nature of species in Book III of his Essay concerning human understanding.

  18. Single visit root canal treatment: A prospective study

    African Journals Online (AJOL)

    2013-08-31

    Aug 31, 2013 ... Post‑operative pain in multiple‑visit and single‑visit root canal treatment. J Endod 2010;36:36‑9. 13. Ferranti P. Treatment of the root canal of an infected tooth in one appointment: A report of 340 cases. Dent Dig 1959;65:49‑53. 14. Ufomata D. One‑visit root canal therapy: A preliminary clinical study in ...

  19. Three root canals in the maxillary second premolar

    Directory of Open Access Journals (Sweden)

    de Almeida-Gomes Fabio

    2009-01-01

    Full Text Available In this study, we report an endodontic treatment of the maxillary second premolar with three root canals and distinct foramens. The possibility of three root canals in this tooth is quite small; however, it must be taken into account in clinical and radiographic evaluation during endodontic treatment. Many times, their presence is noticed only after canal treatment due to continuing post-operative discomfort.

  20. Design and development of a password- based door lock security ...

    African Journals Online (AJOL)

    This work is a design and development of a micro-controller based, password enabled door lock for home security. The work involved building a working model of a security door lock that is password protected with an AT89C52 microcontroller which operates by sending control signals to a H-bridge that controls the ...

  1. Locking plate osteosynthesis of clavicle fractures

    DEFF Research Database (Denmark)

    Fridberg, Marie; Ban, Ilija; Issa, Zaid

    2013-01-01

    PURPOSE: Locking plate osteosynthesis has become the preferred method for operative treatment of clavicle fractures. The method offers stable fixation, and would theoretically be associated with a low rate of fracture-related complications and reoperations. However, this remains to be explored...... in a large cohort, and our purpose was to assess the overall rates of complications and reoperations following locking plate osteosynthesis of mid-shaft clavicle fractures. METHODS: We identified all locking plate osteosynthesis of mid-shaft clavicle fractures operated upon in our department from January...... 2008 to November 2010 (n = 114). Nine patients did not attend the follow-up at our institution. The study group of 105 fractures (104 patients, 86 males) had a median age of 36 years (14-75 years). Follow-up ranged from 0.5 to 3.5 years. No patients were allowed to load the upper extremity for six...

  2. Using river locks to teach hydrodynamic concepts

    CERN Document Server

    Carvalho-Santos, Vagson L; Silva, Enisvaldo C; Rios, Márcio L; Silva, Anderson A P

    2013-01-01

    In this work, the use of a river lock as a non-formal setting for teaching Q2 hydrodynamical concepts is proposed. In particular, we describe the operation of a river lock situated at the Sobradinho dam, on the S\\~ao Francisco River (Brazil). A model to represent and to analyse the dynamics of river lock operation is presented and we derive the dynamical equations for the rising of the water column as an example to understand the Euler equation. Furthermore, with this activity, we enable the integration of content initially introduced in the classroom with practical applications, thereby allowing the association of physical themes to content relevant in disciplines such as history and geography. In addition, experiences of this kind enable teachers to talk about the environmental and social impacts caused by the construction of a dam and, consequently, a crossover of concepts has been made possible, leading to more meaningful learning for the students.

  3. Design of canals

    CERN Document Server

    Swamee, P K

    2015-01-01

    The book presents firsthand material from the authors on design of hydraulic canals. The book discusses elements of design based on principles of hydraulic flow through canals. It covers optimization of design based on usage requirements and economic constraints. The book includes explicit design equations and design procedures along with design examples for varied cases. With its comprehensive coverage of the principles of hydraulic canal design, this book will prove useful to students, researchers, and practicing engineers. End-of-chapter pedagogical elements make it ideal for use in graduate courses on hydraulic structures offered by most civil engineering departments across the world.

  4. Diode array pumped, non-linear mirror Q-switched and mode-locked ...

    Indian Academy of Sciences (India)

    A non-linear mirror consisting of a lithium triborate crystal and a dichroic output coupler are used to mode-lock (passively) an Nd : YVO4 laser, pumped by a diode laser array. The laser can operate both in cw mode-locked and simultaneously Q-switched and mode-locked (QML) regime. The peak power of the laser while ...

  5. Lock-free parallel garbage collection

    NARCIS (Netherlands)

    Gao, H.; Groote, J.F.; Hesselink, W.H.; Pan, Y; Chen, D; Guo, M; Cao, JN; Dongarra, J

    2005-01-01

    This paper presents a lock-free parallel algorithm for garbage collection in a realistic model using synchronization primitives offered by machine architectures. Mutators and collectors can simultaneously operate on the data structure. In particular no strict alternation between usage and cleaning

  6. 33 CFR 117.769 - Black Rock Canal.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Black Rock Canal. 117.769 Section 117.769 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New York § 117.769 Black Rock Canal. The draws of the...

  7. 33 CFR 117.159 - Grant Line Canal.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Grant Line Canal. 117.159 Section 117.159 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements California § 117.159 Grant Line Canal. The draw of the...

  8. MIMO LPV State-Space Identification of Open-Flow Irrigation Canal Systems

    Directory of Open Access Journals (Sweden)

    Yolanda Bolea

    2012-01-01

    Full Text Available Canal systems are complex nonlinear, distributed parameter systems with changing parameters according to the operating point. In this paper, a linear parameter-varying (LPV state-space canal control model is obtained by identification in a local way using a multimodel approach. This LPV identification procedure is based on subspace methods for different operating points of an irrigation canal covering the full operation range. Different subspace algorithms have been used and compared. The model that best represents the canal behavior in a precise manner has been chosen, and it has been validated by error functions and analysis correlation of residuals in a laboratory multireach pilot canal providing satisfactory results.

  9. Reasoning about Java's Reentrant Locks

    NARCIS (Netherlands)

    Haack, C.; Huisman, Marieke; Hurlin, C.; Ramalingam, G.

    2008-01-01

    This paper presents a verification technique for a concurrent Java-like language with reentrant locks. The verification technique is based on permission-accounting separation logic. As usual, each lock is associated with a resource invariant, i.e. when acquiring the lock the resources are obtained

  10. Hydraulic Structures : Locks

    NARCIS (Netherlands)

    Molenaar, W.F.

    These lecture notes on locks are part of the study material belonging to the course 'Hydraulic Structures 1' (code CT3330), part of the Bachelor of Science and the Master of Science, the Hydraulic Engineering track, for civil engineering students at Delft University of Technology. Many of the

  11. Roller Locking Brake

    Science.gov (United States)

    Vranish, John M.

    1993-01-01

    Roller locking brake is normally braking rotary mechanism allowing free rotation when electromagnet in mechanism energized. Well suited to robots and other machinery which automatic braking upon removal of electrical power required. More compact and reliable. Requires little electrical power to maintain free rotation and exhibits minimal buildup of heat.

  12. Locked nucleic acid

    DEFF Research Database (Denmark)

    Jepsen, Jan Stenvang; Sørensen, Mads D; Wengel, Jesper

    2004-01-01

    Locked nucleic acid (LNA) is a class of nucleic acid analogs possessing very high affinity and excellent specificity toward complementary DNA and RNA, and LNA oligonucleotides have been applied as antisense molecules both in vitro and in vivo. In this review, we briefly describe the basic physioc...

  13. Locks and Keys Service

    CERN Multimedia

    Claude Ducastel

    The GS-LS-SEM section is pleased to inform you that as from Monday 30 November 2009, the opening hours of the Locks and Keys service will be the following: 08h30 - 12h30 / 13h30 - 16:30, Mondays to Fridays. GS-SEM-LS 73333

  14. The fluid mechanics of root canal irrigation.

    Science.gov (United States)

    Gulabivala, K; Ng, Y-L; Gilbertson, M; Eames, I

    2010-12-01

    Root canal treatment is a common dental operation aimed at removing the contents of the geometrically complex canal chambers within teeth; its purpose is to remove diseased or infected tissue. The complex chamber is first enlarged and shaped by instruments to a size sufficient to deliver antibacterial fluids. These irrigants help to dissolve dying tissue, disinfect the canal walls and space and flush out debris. The effectiveness of the procedure is limited by access to the canal terminus. Endodontic research is focused on finding the instruments and clinical procedures that might improve success rates by more effectively reaching the apical anatomy. The individual factors affecting treatment outcome have not been unequivocally deciphered, partly because of the difficulty in isolating them and in making the link between simplified, general experimental models and the complex biological objects that are teeth. Explicitly considering the physical processes within the root canal can contribute to the resolution of these problems. The central problem is one of fluid motion in a confined geometry, which makes the dispersion and mixing of irrigant more difficult because of the absence of turbulence over much of the canal volume. The effects of treatments can be understood through the use of scale models, mathematical modelling and numerical computations. A particular concern in treatment is that caustic irrigant may penetrate beyond the root canal, causing chemical damage to the jawbone. In fact, a stagnation plane exists beyond the needle tip, which the irrigant cannot penetrate. The goal is therefore to shift the stagnation plane apically to be coincident with the canal terminus without extending beyond it. Needle design may solve some of the problems but the best design for irrigant penetration conflicts with that for optimal removal of the bacterial biofilm from the canal wall. Both irrigant penetration and biofilm removal may be improved through canal fluid

  15. Extracting Environmental Benefits from a New Canal in Nicaragua: Lessons from Panama.

    Science.gov (United States)

    Condit, Richard

    2015-07-01

    Biologists have raised objections to a new canal in Nicaragua, but in this Essay I argue that dire predictions of environmental catastrophe are exaggerated. I present an alternative view based on my research experience in Panama, where Canal operations foster forest conservation. Currently in Nicaragua, the rate of forest loss is so rapid that the canal cannot make it worse. Rather, I contend, adoption of international standards in canal construction could lead to net environmental and social benefits for the country.

  16. Investigation on Locking and Pulling Modes in Analog Frequency Dividers

    Directory of Open Access Journals (Sweden)

    Antonio Buonomo

    2013-01-01

    Full Text Available We compare the main analytical results available to estimate the locking range, which is the key figure-of-merit of LC frequency dividers based on the injection locking phenomenon. Starting from the classical result by Adler concerning injection-locked oscillators, we elucidate the merits and the shortcomings of the different approaches to study injection-locked frequency dividers, with particular emphasis on divider-by-2. In particular, we show the potential of a perturbation approach which enables a more complete analysis of frequency dividers, making it possible to calculate not only the amplitude and the phase of the locked oscillation, but also the region where it exists and is stable, which defines the locking region. Finally, we analyze the dynamical behaviour of the dividers in the vicinity of the boundary of the locking region, showing that there exists a border region where the occurrence of the locking or the pulling operation mode is possible, depending on the initial conditions of the system.

  17. Innovation and Lock-in

    DEFF Research Database (Denmark)

    Cantner, Uwe; Vannuccini, Simone

    2016-01-01

    This study focuses on a well-known but yet elusive concept: (technological) lock-in. We summarize what is known about the nature of lock-in and offer a critical view on history-dependent processes based on recent contributions to the literature. We discuss if lock-ins are really inescapable......, especially when innovation is concerned. Also, we address the question if lock-in is a well-defined concept at all. To offer a fresh view on lock-in and to tackle the issues just raised, we employ the replicator dynamics model. By making a parallel between monopolization in the replicator dynamics...... and the occurrence of lock-ins, we show that the convergence of a system to a given outcome can be reversed, under certain conditions. We highlight the need for a more precise demarcation of the conceptual boundaries of lock-in and path dependence, both from the formal and the empirical side, and suggest...

  18. Functional outcome of surgical management of degenerative lumbar canal stenosis

    Directory of Open Access Journals (Sweden)

    Rajendra Nath

    2012-01-01

    Conclusion: Operative treatment in patients of degenerative lumbar canal stenosis yields excellent results as observed on the basis of JOA scoring system. No patient got recurrence of symptoms of nerve compression.

  19. Avoiding lock-in

    DEFF Research Database (Denmark)

    Henriksen, Ingrid

    1999-01-01

    The paper investigates the initial phase of the cooperative organisation of agricultural processing firms in Denmark. It argues that the variations observed can be explained within the framework of the theory of industrial organisation. The focus is on the success of cooperative creameries. In 19...... of gathering information and of preserving and transporting a perishable product, were ideally suited to overcome the problems of potential lock-in and of asymmetric information...

  20. Data port security lock

    Science.gov (United States)

    Quinby, Joseph D [Albuquerque, NM; Hall, Clarence S [Albuquerque, NM

    2008-06-24

    In a security apparatus for securing an electrical connector, a plug may be fitted for insertion into a connector receptacle compliant with a connector standard. The plug has at least one aperture adapted to engage at least one latch in the connector receptacle. An engagement member is adapted to partially extend through at least one aperture and lock to at least one structure within the connector receptacle.

  1. Mode-locked fiber laser based on chalcogenide microwires.

    Science.gov (United States)

    Al-Kadry, Alaa; El Amraoui, Mohammed; Messaddeq, Younès; Rochette, Martin

    2015-09-15

    We report the first mode-locked fiber laser using a chalcogenide microwire as the nonlinear medium. The laser is passively mode-locked with nonlinear polarization rotation and can be adjusted for the emission of solitons or noise-like pulses. The use of the microwire leads to a mode-locking threshold at the microwatt level and shortens the cavity length by 4 orders of magnitude with respect to other lasers of its kind. The controlled birefringence of the microwire, combined with a linear polarizer in the cavity, enables multiwavelength laser operation with tunable central wavelength, switchable wavelength separation, and a variable number of laser wavelengths.

  2. Multifrequency zero-jitter delay-locked loop

    Science.gov (United States)

    Efendovich, Avner; Afek, Yachin; Sella, Coby; Bikowsky, Zeev

    1994-01-01

    The approach of an all-digital phase locked loop is used in this delay-locked loop circuit. This design is designated to a system with two processing units, a master CPU and a slave system chip, that share the same bus. It allows maximum utilization of the bus, as the minimal skew between the clocks of the two components significantly reduces idle periods, and also set-up and hold times. Changes in the operating frequency are possible, without falling out of synchronization. Due to the special lead-lag phase detector, the jitter of the clock is zero, when the loop is locked, under any working conditions.

  3. Bilateral bifid mandibular canal

    Directory of Open Access Journals (Sweden)

    Mahnaz Sheikhi

    2012-01-01

    Full Text Available One of the normal interesting variations that we may encounter in the mandible is bifid mandibular canal. This condition can lead to difficulties when performing mandibular anesthesia or during extraction of lower third molar, placement of implants, and surgery in the mandible. Therefore diagnosis of this variation is sometimes very important and necessary.

  4. Pressure locking and thermal binding of gate valves

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, E.M.

    1996-12-01

    Pressure locking and thermal binding represent potential common mode failure mechanisms that can cause safety-related power-operated gate valves to fail in the closed position, thus rendering redundant safety-related systems incapable of performing their safety functions. Supplement 6 to Generic Letter 89-10, {open_quotes}Safety-Related Motor-Operated Gate Valve Testing and Surveillance,{close_quotes} provided an acceptable approach to addressing pressure locking and thermal binding of gate valves. More recently, the NRC has issued Generic Letter 95-07, {open_quotes}Pressure Locking and Thermal Binding of Safety-Related Power-Operated Gate Valves,{close_quotes} to request that licensees take certain actions to ensure that safety-related power-operated gate valves that are susceptible to pressure locking or thermal binding are capable of performing their safety functions within the current licensing bases. Over the past two years, several plants in Region I determined that valves in certain systems were potentially susceptible to pressure locking and thermal binding, and have taken various corrective actions. The NRC Region I Systems Engineering Branch has been actively involved in the inspection of licensee actions in response to the pressure locking and thermal binding issue. Region I continues to maintain an active involvement in this area, including participation with the Office of Nuclear Reactor Regulation in reviewing licensee responses to Generic Letter 95-07.

  5. 49 CFR 236.338 - Mechanical locking required in accordance with locking sheet and dog chart.

    Science.gov (United States)

    2010-10-01

    ... locking sheet and dog chart. 236.338 Section 236.338 Transportation Other Regulations Relating to... in accordance with locking sheet and dog chart. Mechanical locking shall be in accordance with locking sheet and dog chart currently in effect. ...

  6. VHDL Model of Electronic-Lock System

    Directory of Open Access Journals (Sweden)

    J. Noga

    2000-04-01

    Full Text Available The paper describes the design of an electronic-lock system which wascompleted as part of the Basic VHDL course in the Department of Controland Measurement Faculty of Electrical Engineering and Informatics,Technical University of Ostrava, Czech Republic in co-operation withthe Department if Electronic Engineering, University of Hull, GreatBritain in the frame of TEMPUS project no. S_JEP/09468-95.

  7. Multiprocessor Real-Time Locking Protocols for Replicated Resources

    Science.gov (United States)

    2016-07-01

    11. [3] G. Elliott. Real - Time Scheduling of GPUs , with Applications in Ad- vanced Automotive Systems. PhD thesis, University of North Car- olina... schedulability . In RTSS ’15. [16] M. Yang, H. Lei, Y. Liao, and F. Rabee. PK-OMLP: An OMLP based k-exclusion real - time locking protocol for multi- GPU ...B. Brandenburg. Scheduling and Locking in Multiprocessor Real - Time Operating Systems. PhD thesis, University of North Carolina, Chapel Hill, NC

  8. Nonsurgical Endodontic Retreatment of Maxillary Second Molar with Two Palatal Root Canals: A Case Report

    Directory of Open Access Journals (Sweden)

    Mahsa Eskandarinezhad

    2012-04-01

    Full Text Available Successful endodontic treatment requires thorough knowledge regarding each root canal system of any tooth and probability of extra canals should be considered. Second maxillary molar with two palatal root canals is not frequent and its incidence reported in literatures is about 0.4–2%. The present case report describes non-surgical retreatment of maxillary second molar with two palatal root canals. Radiographic interpretation is difficult in this region; so, very careful examination of pulpal space and using supportive devices such as loupe and operating microscope is recommended to discover any unusual anatomic features like extra canals.

  9. Second mesiobuccal canal detection in maxillary first molars using microscopy and ultrasonics.

    Science.gov (United States)

    Alaçam, Tayfun; Tinaz, Ali Cemal; Genç, Ozgür; Kayaoglu, Guven

    2008-12-01

    The aim of this study was to investigate whether the use of operating microscope in combination with ultrasonics increased the rate of second mesiobuccal (MB2) canal detection in permanent maxillary first molar teeth. A hundred extracted human maxillary first molars were assessed. After location of the main canals, the MB2 canal was sought in all teeth first without microscopy, then with the aid of the operating microscope and finally with the combined use of the operating microscope and ultrasonics. With these techniques, the MB2 canal was detected in 62%, 67% and 74% of the teeth, respectively. The combination of the operating microscope and ultrasonics detected significantly more MB2 canals than when no microscopy was utilized (P ultrasonics increased the detection of MB2 canals in maxillary first permanent molars.

  10. Anterior locking plate reduces trochanteric fracture migrations during hip extension.

    Science.gov (United States)

    Cloutier, Luc P; Laflamme, G Yves; Menard, Jeremie; Petit, Yvan

    2014-09-01

    Greater trochanter fractures or osteotomies fixed with lateral plates still present high rates of complications. Unblocked greater trochanter anterior movement during hip extension might be a possible cause of failure. This study aimed to determine, under stair climbing conditions, the biomechanical behaviour of a greater trochanter fragment and the impact of an anterior locking plate on its migration. Eighteen femurs paired from nine fresh frozen cadaveric specimens were tested on a quasi-dynamic stair climbing cycling test bench. Left and right sides with greater trochanter fractures were randomly fixed either with an antero-lateral locking plate or with a lateral locking plate. Migrations, defined as the remaining movements of the unloaded greater trochanter fragment, were measured for all 18 femurs. During hip extension, multi-directional greater trochanter fragment movements occurred and showed a back-and-forth anterior rotation. The lateral locking plate failed due to greater trochanter fragment rotation around the superior axis and anterior translation. The antero-lateral locking plate significantly reduced greater trochanter anterior migration (-0.9 mm ± 1.6) compared to the lateral locking plate (9.6 mm ± 9.5). Hip extension provides a plausible explanation for the high rate of post-operative failures of greater trochanter fixations. An antero-lateral locking plate represents an efficient surgical alternative counteracting the multi-directional greater trochanter movements occurring during hip extension. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. 49 CFR 236.330 - Locking dog of switch-and-lock movement.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Locking dog of switch-and-lock movement. 236.330 Section 236.330 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... Rules and Instructions § 236.330 Locking dog of switch-and-lock movement. Locking dog of switch-and-lock...

  12. Hydrology and environmental aspects of Erie Canal (1817-99)

    Science.gov (United States)

    Langbein, Walter Basil

    1976-01-01

    As the first major water project in the United States, the old Erie Canal provides an example of the hydrological and environmental consequences of water development. The available record shows that the project aroused environmental fears that the canal might be impaired by the adverse hydrologic effects of land development induced by the canal. Water requirements proved greater than anticipated, and problems of floods and hydraulic inefficiencies beset navigation throughout its history. The Erie Canal proved the practicality of major hydraulic works to the extent that operations and maintenance could cope with the burdens of deficiencies in design. The weight of prior experience that upland streams, such as the Potomac and Mohawk Rivers, had proved unsatisfactory for dependable navigation, led to a decision to build an independent canal which freed the location from the constraints of river channels and made possible a cross-country water route directly to Lake Erie. The decision on dimensioning the canal prism--chiefly width and depth-involved balance between a fear of building too small and thus not achieving the economic potentials, and a fear of building too expensively. The constraints proved effective, and for the first part of its history the revenues collected were sufficient to repay all costs. So great was the economic advantage of the canal that the rising trend in traffic soon induced an enlargement of the canal cross section, based upon a new but riskier objective-build as large as the projected trend in toll revenues would finance. The increased revenues did not materialize. Water supplies were a primary concern for both the planners and the operators of the canal. Water required for lockage, although the most obvious to the planners, proved to be a relatively minor item compared with the amounts of water that were required to compensate for leakage through the bed and banks of the canal. Leakage amounted to about 8 inches of depth per day. The total

  13. Managing curved canals

    Directory of Open Access Journals (Sweden)

    Iram Ansari

    2012-01-01

    Full Text Available Dilaceration is the result of a developmental anomaly in which there has been an abrupt change in the axial inclination between the crown and the root of a tooth. Dilaceration can be seen in both the permanent and deciduous dentitions, and is more commonly found in posterior teeth and in maxilla. Periapical radiographs are the most appropriate way to diagnose the presence of root dilacerations. The controlled regularly tapered preparation of the curved canals is the ultimate challenge in endodontics. Careful and meticulous technique will yield a safe and sufficient enlargement of the curved canals. This article gives a review of the literature and three interesting case reports of root dilacerations.

  14. Breaking Carbon Lock-in

    DEFF Research Database (Denmark)

    Driscoll, Patrick Arthur

    2014-01-01

    This central focus of this paper is to highlight the ways in which path dependencies and increasing returns (network effects) serve to reinforce carbon lock-in in large-scale road transportation infrastructure projects. Breaking carbon lock-in requires drastic changes in the way we plan future...

  15. Canal plane dynamic visual acuity in superior canal dehiscence.

    Science.gov (United States)

    Janky, Kristen L; Zuniga, M Geraldine; Ward, Bryan; Carey, John P; Schubert, Michael C

    2014-06-01

    1) To characterize normal, horizontal active dynamic visual acuity (DVA) and passive canal plane head thrust DVA (htDVA) across ages to establish appropriate control data and 2) to determine whether horizontal active DVA and passive canal plane htDVA are significantly different in individuals with superior canal dehiscence syndrome (SCDS) before and after surgical repair in the acute (within 10 d) and nonacute stage (>6 wk). Prospective study. Tertiary referral center Patients diagnosed with SCDS (n = 32) and healthy control subjects (n = 51). Surgical canal plugging on a subset of patients. Static visual acuity (SVA), active horizontal DVA, and canal plane htDVA. Visual acuity (SVA, active DVA, and htDVA) declines with age. In SCDS, SVA and active DVA are not significantly affected in individuals after surgical canal plugging; however, htDVA in the plane of the affected canal is significantly worse after canal plugging. Age-based normative data are necessary for DVA testing. In SCDS, htDVA in the plane of the affected canal is normal before surgery but permanently reduced afterward.

  16. The Nicaragua Canal:Security And Economic Boom Or Bust

    Science.gov (United States)

    2014-04-01

    but is the property of the United States government. Abstract Since the 1800s nations and entrepreneurs have sought a maritime route across...across Central America to compete with the Panama Canal and thus secure his future with Nicaragua. Since the 1800s nations and entrepreneurs have...for the environmental effects that construction and operation of a canal could have on the regional ecosystem . As a result, environmentalists have

  17. Analysis of sedimentation of canals

    Directory of Open Access Journals (Sweden)

    Agunwamba, J.C.,

    2013-03-01

    Full Text Available The dredged canals in the Niger Delta coastal flood plain are being threatened by siltation. This study is limited to those canals in Rivers State of Nigeria, which are under the influence of tidal waves. A total of eight canals were considered with four each from Ekulama and Cawthorne Channel. Different approaches were used to carry out this study, which includes field reconnaissance survey, hydrographic survey, soil sample analysis and collection of all available data and information. The typical bed materials size (D50 is approximately 0.01mm; which gives a settling velocity of 0.09mm/sec using stroke’s law. Hydrographic survey of the canals from 1992 to 1996 revealed an average siltation rate of 2.35m/yr. A regression equation was also derived which relates the cost of dredging to canal area, rate of siltation and average aggregation. A plot of canal centre profile; entrance, middle and end cross sections showing sediment distribution along the canal profile, shows that majority of the particles that form the sediment enter the canal from the rivers. The sedimentation is caused by the reduction in water current, which has average value of 0.0145m/sec. The bathyorographical check on the canals revealed that the sum of the two exterior angles of the canal with the river at the point of connection has to lie within 1800 + 50 for an effective flow that will minimize settlement of particles. In addition, the canals should be constructed to start and terminate on a moving water body, to avoid dead ends. A regression equation was determined which relates the cost of dredging to canal area, rate of siltation and average aggradations.

  18. Management of middle mesial canal in mandibular second molar

    Directory of Open Access Journals (Sweden)

    J V Karunakaran

    2012-01-01

    Full Text Available The primary objective of endodontic therapy is to achieve a three-dimensional obturation of the root canal space after adequate preparation of the canal space to remove the tissue debris, microorganisms, and their byproducts. Anatomical variations have frequently been encountered in endodontic practice and have to be adequately managed by the clinician. Missed roots and canals are a major reason for failure of therapy. Technological advances have given the clinician ample opportunity to identify and treat these aberrations successfully. The present report describes a left mandibular second permanent molar requiring root canal treatment, found to have three separate canals in the mesial root. This case demonstrates a rare anatomical configuration and emphasizes the need for the clinician to be aware of and look out for such variations and use adequate diagnostic methodologies prior to and during therapy to detect such variations. The possibility of additional canals, whenever in doubt, should be explored with the assistance of technologies such as those of magnification and illumination and various diagnostic aids. Operator experience has also shown to be a key factor in negotiation and management of these aberrant canal configurations.

  19. Modeling and measurement of root canal using stereo digital radiography

    Science.gov (United States)

    Analoui, Mostafa; Krisnamurthy, Satthya; Brown, Cecil

    2000-04-01

    Determining root canal length is a crucial step in success of root canal treatment. Root canal length is commonly estimated based on pre-operation intraoral radiography. 2D depiction of a 3D object is the primary source of error in this approach. Techniques based on impedance measurement are more accurate than radiographic approaches, but do not offer a method for depicting the shape of canal. In this study, we investigated a stererotactic approach for modeling and measurement of root canal of human dentition. A weakly perspective model approximated the projectional geometry. A series of computer-simulated objects was used to test accuracy of this model as the first step. The, to assess the clinical viability of such an approach, endodontic files inserted in the root canal phantoms were fixed on an adjustable platform between a radiographic cone and an image receptor. Parameters of projection matrix were computed based on the relative positions of image receptors, focal spot, and test objects. Rotating the specimen platform from 0 to 980 degrees at 5-degree intervals set relative angulations for stereo images. Root canal is defined as the intersection of two surfaces defined by each projection. Computation of error for length measurement indicates that for angulations greater than 40 degrees the error is within clinically acceptable ranges.

  20. Maxillary First Molars with Six Canals Diagnosed with the Aid of Cone Beam Computed Tomography: A Report of Two Cases

    Directory of Open Access Journals (Sweden)

    Mamta Kaushik

    2013-01-01

    Full Text Available The case reports present the endodontic management of two maxillary first molars with six canals. The diagnosis of morphology of multiple canal systems was identified under magnification of the dental operating microscope and was confirmed with the help of cone beam computed tomography. This paper discusses the variations in the canal morphology and the use of the latest adjuncts in successfully diagnosing and treating unusual canal anatomy.

  1. Radio Frequency and Terahertz Signals Generated by Passively Mode-Locked Semiconductor Lasers

    OpenAIRE

    Latkowski, Sylwester

    2010-01-01

    There are several different approaches to generating periodic signals using semiconductor lasers, for example: Q-switching, gain switching or mode-locking schemes. In general the active or passive mode-locking techniques require the use of a modulator or a saturable absorber in order to achieve the phase synchronisation. The laser diodes studied in this thesis, are demonstrated to operate in the mode-locked regime, while not requiring any direct or external modulation, nor the saturable absor...

  2. Widely tunable Tm-doped mode-locked all-fiber laser

    OpenAIRE

    Yan, Zhiyu; Sun, Biao; Li, Xiaohui; Luo, Jiaqi; Shum, Perry Ping; Yu, Xia; Zhang, Ying; Wang, Qi Jie

    2016-01-01

    We demonstrated a widely tunable Tm-doped mode-locked all-fiber laser, with the widest tunable range of 136?nm, from 1842 to 1978?nm. Nonlinear polarization evolution (NPE) technique is employed to enable mode-locking and the wavelength-tunable operation. The widely tunable range attributes to the NPE-induced transmission modulation and bidirectional pumping mechanism. Such kind of tunable mode-locked laser can find various applications in optical communications, spectroscopy, time-resolved m...

  3. Lumbar canal stenosis.

    Science.gov (United States)

    Mazanec, D J; Drucker, Y; Segal, A M

    1997-04-01

    Lumbar canal stenosis is an increasingly recognized condition in patients more than 65 years of age. The clinical syndrome is dominated by neurogenic claudication. The natural history of the Condition is not yet well described. Long-term results of surgical therapy are frequently disappointing, and reoperation is required in more than 10% of patients. Nonoperative treatment options include physical therapy exercise programs, calcitonin, analgesics, and epidural steroid injections. A clinical pathway for management of symptomatic stenosis, emphasizing an initial nonoperative approach, is suggested.

  4. Is John Locke a democrat?

    DEFF Research Database (Denmark)

    Svensson, Palle

      Over recent years there has been a tendency to present John Locke as an equalitarian democrat (Ashcraft) and being close to the political views of the levellers (Waldron). This is not a completely new interpretation (Kendall, 1941), but contrasts with the prevalent view presented in textbooks...... (Holden, Held, Ball and Dagger) and monographs on Locke (Dunn, Parry, Marshall). In this paper a new approach to the democratic character of John Locke's political theory is suggested, as his Second Treatise is analysed with Robert A. Dahl's conceptual framework on assumptions for a democratic order...

  5. First harmonic injection locking of 24-GHz-oscillators

    Directory of Open Access Journals (Sweden)

    M. R. Kühn

    2003-01-01

    Full Text Available An increasing number of applications is proposed for the 24 GHz ISM-band, like automotive radar systems and short-range communication links. These applications demand for oscillators providing moderate output power of a few mW and moderate frequency stability of about 0.5%. The maximum oscillation frequency of low-cost off-theshelf transistors is too low for stable operation of a fundamental 24GHz oscillator. Thus, we designed a 24 GHz first harmonic oscillator, where the power generated at the fundamental frequency (12 GHz is reflected resulting in effective generation of output power at the first harmonic. We measured a radiated power from an integrated planar antenna of more than 1mW. Though this oscillator provides superior frequency stability compared to fundamental oscillators, for some applications additional stabilization is required. As a low-cost measure, injection locking can be used to phase lock oscillators that provide sufficient stability in free running mode. Due to our harmonic oscillator concept injection locking has to be achieved at the first harmonic, since only the antenna is accessible for signal injection. We designed, fabricated and characterized a harmonic oscillator using the antenna as a port for injection locking. The locking range was measured versus various parameters. In addition, phase-noise improvement was investigated. A theoretical approach for the mechanism of first harmonic injection locking is presented.

  6. Spinal canal stenosis; Spinalkanalstenose

    Energy Technology Data Exchange (ETDEWEB)

    Papanagiotou, P.; Boutchakova, M. [Klinikum Bremen-Mitte/Bremen-Ost, Klinik fuer Diagnostische und Interventionelle Neuroradiologie, Bremen (Germany)

    2014-11-15

    Spinal stenosis is a narrowing of the spinal canal by a combination of bone and soft tissues, which can lead to mechanical compression of spinal nerve roots or the dural sac. The lumbal spinal compression of these nerve roots can be symptomatic, resulting in weakness, reflex alterations, gait disturbances, bowel or bladder dysfunction, motor and sensory changes, radicular pain or atypical leg pain and neurogenic claudication. The anatomical presence of spinal canal stenosis is confirmed radiologically with computerized tomography, myelography or magnetic resonance imaging and play a decisive role in optimal patient-oriented therapy decision-making. (orig.) [German] Die Spinalkanalstenose ist eine umschriebene, knoechern-ligamentaer bedingte Einengung des Spinalkanals, die zur Kompression der Nervenwurzeln oder des Duralsacks fuehren kann. Die lumbale Spinalkanalstenose manifestiert sich klinisch als Komplex aus Rueckenschmerzen sowie sensiblen und motorischen neurologischen Ausfaellen, die in der Regel belastungsabhaengig sind (Claudicatio spinalis). Die bildgebende Diagnostik mittels Magnetresonanztomographie, Computertomographie und Myelographie spielt eine entscheidende Rolle bei der optimalen patientenbezogenen Therapieentscheidung. (orig.)

  7. Complete atrioventricular canal

    Directory of Open Access Journals (Sweden)

    Limongelli Giuseppe

    2006-04-01

    Full Text Available Abstract Complete atrioventricular canal (CAVC, also referred to as complete atrioventricular septal defect, is characterised by an ostium primum atrial septal defect, a common atrioventricular valve and a variable deficiency of the ventricular septum inflow. CAVC is an uncommon congenital heart disease, accounting for about 3% of cardiac malformations. Atrioventricular canal occurs in two out of every 10,000 live births. Both sexes are equally affected and a striking association with Down syndrome was found. Depending on the morphology of the superior leaflet of the common atrioventricular valve, 3 types of CAVC have been delineated (type A, B and C, according to Rastelli's classification. CAVC results in a significant interatrial and interventricular systemic-to-pulmonary shunt, thus inducing right ventricular pressure and volume overload and pulmonary hypertension. It becomes symptomatic in infancy due to congestive heart failure and failure to thrive. Diagnosis of CAVC might be suspected from electrocardiographic and chest X-ray findings. Echocardiography confirms it and gives anatomical details. Over time, pulmonary hypertension becomes irreversible, thus precluding the surgical therapy. This is the reason why cardiac catheterisation is not mandatory in infants (less than 6 months but is indicated in older patients if irreversible pulmonary hypertension is suspected. Medical treatment (digitalis, diuretics, vasodilators plays a role only as a bridge toward surgery, usually performed between the 3rd and 6th month of life.

  8. 49 CFR 236.765 - Locking, mechanical.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Locking, mechanical. 236.765 Section 236.765 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Locking, mechanical. An arrangement of locking bars, dogs, tappets, cross locking and other apparatus by...

  9. 49 CFR 236.336 - Locking bed.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Locking bed. 236.336 Section 236.336 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Instructions § 236.336 Locking bed. The various parts of the locking bed, locking bed supports, and tappet stop...

  10. Dually-mode-locked ND: YAG laser

    Science.gov (United States)

    Osmundson, J.; Rowe, E.; Santarpia, D.

    1974-01-01

    Mode-locking is stabilized effectively by conventional loss-modulator and phase-modulator, mode-locking elements placed in laser cavity in optical series with one another. Resulting dually-mode-locked system provides pulses with constant phase relative to mode-lock drive signal without presence of relaxation oscillation noise.

  11. John locke on personal identity.

    Science.gov (United States)

    Nimbalkar, Namita

    2011-01-01

    John Locke speaks of personal identity and survival of consciousness after death. A criterion of personal identity through time is given. Such a criterion specifies, insofar as that is possible, the necessary and sufficient conditions for the survival of persons. John Locke holds that personal identity is a matter of psychological continuity. He considered personal identity (or the self) to be founded on consciousness (viz. memory), and not on the substance of either the soul or the body.

  12. Microscope magnification and ultrasonic precision guidance for location and negotiation of second mesiobuccal canal: An in vivo study.

    Science.gov (United States)

    Sujith, Ramachandra; Dhananjaya, Kiranmurthy; Chaurasia, Vishwajit Rampratap; Kasigari, Deepa; Veerabhadrappa, Anusha Channabasappa; Naik, Sachin

    2014-12-01

    The aim of this study was to evaluate the influence of using the dental operating microscope (DOM) and ultrasonics for the detection of second mesiobuccal (MB2) canal orifice in maxillary first molars. Sixty subjects seeking root canal therapy for maxillary first molar were assessed for the presence of MB2 canal using endodontic explorer without magnification. Teeth in which the MB2 canal orifice could not be located were examined under magnification using DOM. If the MB2 canal orifice could not be found even after using DOM, ultrasonic tips were used to prepare 3-mm-long trough from the mesiobuccal canal orifice toward the palatal canal and examined under DOM for location of the canal. With naked eye, the MB2 canal was located in 12 teeth; with the use of the DOM, the MB2 canal was located in 21 additional teeth; and with the combined use of ultrasonic tip and DOM, the MB2 canal was located in 9 more teeth. Statistical comparisons between the tested techniques were done by analyzing the Receiver Operating Characteristic (ROC) curves; a statistically significant difference was found (P < 0.001). The results of this study indicate that the DOM and ultrasonics provide increased opportunity for the dentist to detect canal orifices.

  13. Marmet Locks and Dam, Kanawha River, West Virginia

    Science.gov (United States)

    2015-07-01

    lapse video systems and an underwater remotely operated vehicle . The purpose of this monitoring study was to determine if the project is...longitudinal culvert system, and Stoney gate valves. The lock was monitored using time-lapse video systems and an underwater remotely operated vehicle . The...culvert system experienced peak average velocities of 18 feet per second, although no adverse pressures were found. A remotely operated vehicle

  14. Seepage study of six canals in Salt Lake County, Utah, 1982-1983

    Science.gov (United States)

    Herbert, L.R.; Cruff, R.W.; Waddell, K.M.

    1985-01-01

    A study of selected reaches of the Utah and Salt Lake, Utah Lake Distributing, Provo Reservoir, Draper Irrigation, East Jordan, and Jordan and Salt Lake City Canals in Salt Lake County, Utah, was made to determine gains or losses of flow in those reaches. Three to five sets of seepage measurements were made on each canal during 1982 or 1983. Adjustments for fluctuations in flow were made from information obtained from water-stage recorders operated at selected locations during the time of each seepage run.The study showed an overall net loss of about 9.5 cubic feet per second in the Utah and Salt Lake Canal, 11.0 cubic feet per second in the Utah Lake Distributing canal, 20.5 cubic feet per second in the Provo Reservoir canal, 1.5 cubic feet per second in the Draper Irrigation Canal, and 4.0 cubic feet per second in the East Jordan canal. It also showed a net gain of about 6.0 cubic feet per second in the Jordan and Salt Lake City Canal. The gains and losses are attributed primarily to the relation of the canals to the depth of the water table near the canals.

  15. Identification of possible factors impacting dental students' ability to locate MB2 canals in maxillary molars.

    Science.gov (United States)

    Park, Ellen; Chehroudi, Babak; Coil, Jeffrey M

    2014-05-01

    This study examined the effect of the access size and straight-line path of access on third-year dental students' ability to locate a second mesiobuccal (MB2) canal in maxillary first and second molars. One hundred and six third-year dental students at one Faculty of Dentistry performed simulated root canal treatment with the aid of 2x magnification loupes on extracted teeth. A postgraduate endodontic student subsequently made a reasonable search for an untreated MB2 canal with the aid of a dental operating microscope. The mesiobuccal roots were then sectioned horizontally for determination of the canal configuration. The dental students were able to treat an MB2 canal in 15.8 percent of the teeth, but this was not associated with satisfactory access criteria. The postgraduate endodontic student identified an MB2 canal in 54.7 percent of the remaining tooth samples excluding those where the MB2 canal was found by the dental students; this represented 94.3 percent of those teeth confirmed by horizontal sectioning of the root to have an MB2 canal. The postgraduate student troughed, on average, 2.6 mm before negotiating the MB2 canal. As satisfactory access criteria and straight-line path of access did not correlate with the dental students' ability to find a second mesiobuccal canal, this result has important implications for educational goals with respect to endodontic treatment of maxillary molar teeth.

  16. Hood Canal Steelhead - Hood Canal Steelhead Supplementation Experiment

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Hood Canal Steelhead Project is a 17-year before-after-control-impact experiment that tests the effects of supplementation on natural steelhead populations in...

  17. CT findings of the osteoma of the external auditory canal

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ha Young; Song, Chang Joon; Yoon, Chung Dae; Park, Mi Hyun; Shin, Byung Seok [Chungnam National University, School of Medicine, Daejeon (Korea, Republic of)

    2006-07-15

    We wanted to report the CT image findings of the osteoma of the external auditory canal. Temporal bone CT scanning was performed on eight patients (4 males and 4 females aged between 8 and 41 years) with pathologically proven osteoma of the external auditory canal after operation, and the findings of the CT scanning were retrospectively reviewed. Not only did we analyze the size, shape, distribution and location of the osteomas, we also analyzed the relationship between the lesion and the tympanosqumaous or tympanomastoid suture line, and the changes seen on the CT scan images for the patients who were able to undergo follow-up. All the lesions of the osteoma of the external auditory canal were unilateral, solitary, pedunculated bony masses. In five patients, the osteomas occurred on the left side and for the other three patients, the osteomas occurred on the right side. The average size of the osteoma was 0.6 cm with the smallest being 0.5 cm and the largest being 1.2 cm. Each of the lesions was located at the osteochondral junction in the terminal part of the osseous external ear canal. The stalk of the osteoma of the external auditory canal was found to have occurred in the anteroinferior wall in five cases (63%), in the anterosuperior wall (the tympanosqumaous suture line) in two cases (25%), and in the anterior wall in one case. The osteoma of the external auditory canal was a compact form in five cases and it was a cancellous form in three cases. One case of the cancellous form was changed into a compact form 35 months later due to the advanced ossification. Osteoma of the external auditory canal developed in a unilateral and solitary fashion. The characteristic image findings show that it is attached to the external auditory canal by its stalk. Unlike our common knowledge about its occurrence, osteoma mostly occurred in the tympanic wall, and this is regardless of the tympanosquamous or tympanomastoid suture line.

  18. Method for Constructing Standardized Simulated Root Canals.

    Science.gov (United States)

    Schulz-Bongert, Udo; Weine, Franklin S.

    1990-01-01

    The construction of visual and manipulative aids, clear resin blocks with root-canal-like spaces, for simulation of root canals is explained. Time, materials, and techniques are discussed. The method allows for comparison of canals, creation of any configuration of canals, and easy presentation during instruction. (MSE)

  19. Medicine in John Locke's philosophy.

    Science.gov (United States)

    Sanchez-Gonzalez, M A

    1990-12-01

    John Locke's philosophy was deeply affected by medicine of his times. It was specially influenced by the medical thought and practice of Thomas Sydenham. Locke was a personal friend of Sydenham, expressed an avid interest in his work and shared his views and methods. The influence of Sydenham's medicine can be seen in the following areas of Locke's philosophy: his "plain historical method"; the emphasis on observation and sensory experience instead of seeking the essence of things; the rejection of hypotheses and principles; the refusal of research into final causes and inner mechanisms; the ideal of irrefutable evidence and skepticism on the possibilities of certainty in science. The science which for Locke held the highest paradigmatic value in his theory of knowledge was precisely medicine. To a great extent, Locke's Essay on Human Understanding can be understood as an attempt to justify, substantiate, and promote Sydenham's medical method. This method, generalized, was then proposed as an instrument for the elaboration of all natural sciences.

  20. Ship Lock as General Queuing System with Batch Arrivals and Batch Service

    Directory of Open Access Journals (Sweden)

    Zoran Radmilović

    2007-11-01

    Full Text Available The real lock operations with ships and barge convoys areconsidered dependent on the transport technologies applied, ormore precisely, the kinds of ships/convoys requiring thelockage. The fleet can be divided as follows: (1 groups of singleships, (2 pushed and pulled tows of barges and (3 differentcombinations of previous systems (1 and (2. The groups ofships and tows passing through the lock have extremely stochasticcharacteristics thus forming various arrivals and setvicetime patterns. It means that uniform navigation or strongscheduling between locks and lock operations are not possibleeven though highly sophisticated equipment is at disposal.Therefore, in this paper an analytical method was developedusing bulk queuing systems for the analysis and planning oflock requirements supporting it with numerical example. Thedeveloped methodology can be applied to determine the meanqueue length of ships - convoys at lock anchorage, withoutblocking behaviour between upstream and downstream navigationfor single-lane traffic.

  1. The healing philosopher: John Locke's medical ethics.

    Science.gov (United States)

    Short, Bradford William

    2004-01-01

    This article examines a heretofore unexplored facet of John Locke's philosophy. Locke was a medical doctor and he also wrote about medical issues that are controversial today. Despite this, Locke's medical ethics has yet to be studied. An analysis of Locke's education and his teachers and colleagues in the medical profession, of the 17th century Hippocratic Oath, and of the reaction to the last recorded outbreak of the bubonic plague in London, shines some light on the subject of Locke's medical ethics. The study of Locke's medical ethics confirms that he was a deontologist who opposed all suicide and abortion through much of pregnancy.

  2. A FUNCTIONAL EVALUATION STUDY OF DISTAL FEMORAL FRACTURES FIXED WITH DISTAL FEMORAL LOCKING PLATE

    Directory of Open Access Journals (Sweden)

    Manikumar C. J

    2017-04-01

    were with fracture on right side and 8 on left side. 3 patients had associated injuries. Of them, 2 patients had comminuted fracture of patella on same side and 1 had ipsilateral tibial fracture. All patients were treated with open reduction and internal fixation. All patients were operated within 8 days. Average time duration of surgery was 101 minutes with shortest duration being 80 mins. and longest being 120 mins. The size of plate was selected based on the type of fracture. Of 20 patients, 14 patients (70% showed radiological union within 18 weeks. No patients had implant failure. Average flexion achieved in this study was 105 degrees with more than 45% patients having knee range of motion more than 110 degrees. Average knee extensor lag in this study was 5.8 degrees. Out of 20 patients, 3 had shortening, 2 patients with shortening of 15 mm and 1 shortening of 10 mm. In this study, 3 patients had significant virus and 3 patients had valgus malalignment with 2 patients had deep infection, which was treated with debridement and antibiotics. The duration of follow-up ranged from 3 months to 18 months. CONCLUSION Locking compression plate is the optimal tool for many fractures in distal femur. It provided rigid fixation in that region of the femur, where a widening canal, thin cortices and frequently poor bone stock, which make fixation difficult. Minimally-invasive surgical exposure for plate placement requires significantly less periosteal stripping and soft tissue exposure than that of other techniques. Early mobilisation postoperatively achieves a greater range of motion of knee, which is of paramount importance.

  3. Model-Based Design and Formal Verification Processes for Automated Waterway System Operations

    Directory of Open Access Journals (Sweden)

    Leonard Petnga

    2016-06-01

    Full Text Available Waterway and canal systems are particularly cost effective in the transport of bulk and containerized goods to support global trade. Yet, despite these benefits, they are among the most under-appreciated forms of transportation engineering systems. Looking ahead, the long-term view is not rosy. Failures, delays, incidents and accidents in aging waterway systems are doing little to attract the technical and economic assistance required for modernization and sustainability. In a step toward overcoming these challenges, this paper argues that programs for waterway and canal modernization and sustainability can benefit significantly from system thinking, supported by systems engineering techniques. We propose a multi-level multi-stage methodology for the model-based design, simulation and formal verification of automated waterway system operations. At the front-end of development, semi-formal modeling techniques are employed for the representation of project goals and scenarios, requirements and high-level models of behavior and structure. To assure the accuracy of engineering predictions and the correctness of operations, formal modeling techniques are used for the performance assessment and the formal verification of the correctness of functionality. The essential features of this methodology are highlighted in a case study examination of ship and lock-system behaviors in a two-stage lock system.

  4. A RARE CASE OF HYDROCOELE OF CANAL OF NUCK

    Directory of Open Access Journals (Sweden)

    Abhishek Kumar

    2016-02-01

    Full Text Available INTRODUCTION Hydrocele of canal of Nuck of female is a rare developmental disorder corresponding to the hydrocele of the spermatic cord of males It results from the failure of obliteration of the distal portion of evaginated parietal peritoneum within the inguinal canal which forms a sac containing fluid. It can be diagnosed on the operating table at the time of operation of suspected incarcerated inguinal hernia. We present a rare case of a 15 year old girl with right-sided groin swelling over 4 years, diagnosed as hydrocele of canal of Nuck. Patient underwent surgical exploration and excision of hydrocele. This entity should be considered in young females presenting with an inguinal swelling.

  5. Looking back at Love Canal

    Energy Technology Data Exchange (ETDEWEB)

    Deegan, J. Jr.

    1987-05-01

    In the first part of this series (ES and T, April 1987, pp. 328-31) it was pointed out that the methods and conclusions of EPA's Love Canal Study were the subject of some controversy in the environmental community. Others defended the agency's approaches and methods. Part 2 makes no attempt to resolve the controversy; its purpose is to present the results and conclusions of the Love Canal.

  6. Coupled optical resonance laser locking.

    Science.gov (United States)

    Burd, S C; du Toit, P J W; Uys, H

    2014-10-20

    We have demonstrated simultaneous laser frequency stabilization of a UV and IR laser, to coupled transitions of ions in the same spectroscopic sample, by detecting only the absorption of the UV laser. Separate signals for locking the different lasers are obtained by modulating each laser at a different frequency and using lock-in detection of a single photodiode signal. Experimentally, we simultaneously lock a 369 nm and a 935 nm laser to the (2)S(1/2) → (2)(P(1/2) and (2)D(3/2) → (3)D([3/2]1/2) transitions, respectively, of Yb(+) ions generated in a hollow cathode discharge lamp. Stabilized lasers at these frequencies are required for cooling and trapping Yb(+) ions, used in quantum information and in high precision metrology experiments. This technique should be readily applicable to other ion and neutral atom systems requiring multiple stabilized lasers.

  7. Single-SectionFabry-Perot Mode-Locked Semiconductor Lasers

    Directory of Open Access Journals (Sweden)

    Weiguo Yang

    2011-01-01

    Full Text Available We present a review of the theoretical models and experimental verification of the single-section Fabry-Perot mode-locked semiconductor lasers based on multiple-spatial-mode (MSM coupling. The mode-locked operation at the repetition rates of 40 GHz and higher and the pulse width of a few picoseconds are confirmed by the intensity autocorrelation, the fast photo detection and RF spectrum, and the optical spectral interference measurement of ultrafast pulse. The spatial mode coupling theory of single-section Fabry-Perot mode-locked semiconductor lasers is also reviewed, and the results are compared with the experimental observations. The small signal modulation response of these lasers, which exhibits high-frequency responses well beyond the relaxation oscillation resonance limit, is also modeled theoretically, and the simulation is verified by the experimental measurements.

  8. Line locking and SS 433

    Science.gov (United States)

    Pekarevich, M.; Piran, T.; Shaham, J.

    1984-01-01

    The general problem of acceleration by line locking in an optically thin medium is considered. Analytic solutions to the coupled equations of radiation transfer and matter motion are presented. Using these solutions, restrictions on the physical conditions of the accelerated matter are derived. By applying these conditions to SS 433, it is found that if the absorbing ion is light (hydrogen or helium), the matter must be highly clumped, and the acceleration has to begin at approximately 10 to the 12th cm. Line-locking acceleration with a hydrogen-like heavy ion such as iron demands higher than solar ion abundance.

  9. Effect of a locking triple pelvic osteotomy plate on screw loosening in 26 dogs.

    Science.gov (United States)

    Rose, Scott A; Peck, Jeffrey N; Tano, Cheryl A; Uddin, Nizam; de Haan, Jacek J

    2012-01-01

    To evaluate the complication rate of the double (DPO) and triple pelvic osteotomy (TPO) procedure (unilateral and bilateral) with a locking purpose-specific plate. Retrospective case series Dogs (n = 26; 38 hips) Medical records (January 2007-January 2011) of dogs that had unilateral or bilateral DPO or TPO were evaluated. Signalment, age, body weight, estimated preoperative subluxation and reduction angles, lameness, and complications were evaluated. Follow-up radiographs were evaluated for implant loosening or failure, femoral head coverage (FCH), pelvic dimensions, and radiographic evidence of healing. Screw loosening occurred in 1 of 266 (0.4%) screws placed and in 1 of 38 hips (2.6%). The rate of screw loosening was significantly lower than previously reported. Only 1 hip (2.6%) developed a major complication. Minor complications involving implants occurred in 2 hips (5.3%). Three to 5 locking screws were used per plate. There was a significant increase in FCH and Norberg angle (NA) compared with preoperative values. No clinically significant change in pelvic canal dimensions measured at 3 locations was identified. Locking 7-hole TPO plates with 3-5 locking screws resulted in a lower rate of major and minor implant associated complications than the reported complication rate for conventional 6-hole plates. En bloc pullout of the caudal aspect of the plate is an infrequent but repeatable complication associated with the locking TPO implant. © Copyright 2011 by The American College of Veterinary Surgeons.

  10. Traumatic L4-5 bilateral locked facet joints.

    Science.gov (United States)

    Zenonos, Georgios A; Agarwal, Nitin; Monaco, Edward A; Okonkwo, David O; Kanter, Adam S

    2016-05-01

    Traumatic bilateral locked facet joints occur with extreme rarity in the lumbar spine. A careful review of the literature revealed only three case reports. We present the case of a 36 year-old male who suffered bilateral L4-5 facet fracture dislocations following a motor vehicle collision. The dislocation was associated with disruption of the posterior elements and a Grade II anterolisthesis of L4 on L5 as well as an epidural hematoma resulting in severe canal narrowing, with the patient remaining neurologically intact on presentation. The patient underwent open reduction with L3 to S1 pedicle screw fixation and arthrodesis to treat this highly unstable injury. The existing literature and a biomechanics review of the lumbar spine are described in the context of the presented case in addition to a proposed mechanism for such dislocations.

  11. In-Chamber Longitudinal Culvert Design for Lock Filling and Emptying System

    National Research Council Canada - National Science Library

    Hite, John

    2003-01-01

    .... Some of these improvements include the addition or replacement of the navigation lock. Innovative design and construction techniques are being investigated for reducing construction costs, as well as operation and maintenance costs...

  12. [The effect of left bacteria in the root canal on prognosis of the root canal therapy].

    Science.gov (United States)

    He, Jin-mei; Bian, Zhuan; Fan, Ming-wen; Fan, Bing

    2004-06-01

    To study the effect of the left bacteria on the root canal therapy. 50 single-rooted teeth with chronic apical periodontitis were divided into two groups, one was instrumented with step-back technique and 2.5%NaOCl ultrasonic irrigation for 3 min, then filled with Thermafil. Samples were taken after instrumentation to culture. The other was treated with traditional RCT at three visits. In 24 months the apical radiolucency were greatly reduced in all cases. There weren't significant relationship among the postoperative pain and the left bacteria, the degree of the obturation or the pre-operative symptoms (P > 0.05). The effect of left bacteria in root canal filled with Thermafil wasn't observed.

  13. Project Integration Architecture: Distributed Lock Management, Deadlock Detection, and Set Iteration

    Science.gov (United States)

    Jones, William Henry

    2005-01-01

    The migration of the Project Integration Architecture (PIA) to the distributed object environment of the Common Object Request Broker Architecture (CORBA) brings with it the nearly unavoidable requirements of multiaccessor, asynchronous operations. In order to maintain the integrity of data structures in such an environment, it is necessary to provide a locking mechanism capable of protecting the complex operations typical of the PIA architecture. This paper reports on the implementation of a locking mechanism to treat that need. Additionally, the ancillary features necessary to make the distributed lock mechanism work are discussed.

  14. Operative treatment of 2-part surgical neck fractures of the proximal humerus (AO 11-A3) in the elderly: Cement augmented locking plate Philos™ vs. proximal humerus nail MultiLoc®.

    Science.gov (United States)

    Helfen, Tobias; Siebenbürger, Georg; Mayer, Marcel; Böcker, Wolfgang; Ockert, Ben; Haasters, Florian

    2016-10-28

    Proximal humeral fractures are with an incidence of 4-5 % the third most common fractures in the elderly. In 20 % of humeral fractures there is an indication for surgical treatment according to the modified Neer-Criteria. A secondary varus dislocation of the head fragment and cutting-out are the most common complications of angle stable locking plates in AO11-A3 fractures of the elderly. One possibility to increase the stability of the screw-bone-interface is the cement augmentation of the screw tips. A second is the use of a multiplanar angle stablentramedullary nail that might provide better biomechanical properties after fixation of 2-part-fractures. A comparison of these two treatment options augmented locking plate versus multiplanar angle stable locking nail in 2-part surgical neck fractures of the proximal humerus has not been carried out up to now. Forty patients (female/male, ≥60 years or female postmenopausal) with a 2-part-fracture of the proximal humerus (AO type 11-A3) will be randomized to either to augmented plate fixation group (PhilosAugment) or to multiplanar intramedullary nail group (MultiLoc). Outcome parameters are Disabilities of the Shoulder, Arm and Hand-Score (DASH) Constant Score (CS), American Shoulder and Elbow Score (ASES), Oxford Shoulder Score (OSS), Range of motion (ROM) and Short Form 36 (SF-36) after 3 weeks, 6 weeks, 3 months, 6 months, 12 and 24 months. Because of the lack of clinical studies that compare cement augmented locking plates with multiplanar humeral nail systems after 2-part surgical neck fractures of the proximal humerus, the decision of surgical method currently depends only on surgeons preference. Because only a randomized clinical trial (RCT) can sufficiently answer the question if one treatment option provides advantages compared to the other method we are planning to perform a RCT. Clinical Trial ( NCT02609906 ), November 18, 2015, registered retrospectively.

  15. Mejoras en el canal de Panamá

    Directory of Open Access Journals (Sweden)

    Brandl, Charles McG.

    1963-07-01

    Full Text Available The Panama Canal, together with the Suez Canal, is an engineering accomplishment which is now regarded as a master work marking the initiation of modern civil engineering. Other projects, also of great magnitude, do not seem to maintain the reputation of the above two, because they cannot continue to serve their function with sustained usefulness in the new circumstances of today. The Panama Canal, with its limited dock capacity, and the narrow, so called Serpent, canal, has had to cope with a continuously increasing volume of shipping traffic; a natural consequence of commercial evolution. In order to keep up with these increasing demands, it has been necessary to carry out an almost uninterrupted series of modifications and improvements, affecting both the method of operation and organisation, and the actual nature of the canal. Thanks to these alterations the Panama Canal has continued to maintain, at least nominally, an adequate standard of functional efficiency. At present the canal is being widened over certain sections to enable the easy passage of ships of great displacement. The work is being done very rapidly, and in order to gain time, it has been distributed to various contractors simultaneously.El canal a través del ismo de Panamá es una obra de ingeniería civil que, junto con el de Suez, empiezan ya a clasificarse como obras maestras que señalan el primer jalón del desarrollo de la ingeniería moderna. Otras obras, también importantes, no conservan, sin embargo, la misma reputación que aquéllas, por no seguir un paralelismo con las exigencias en cada época. El canal de Panamá, con sus exclusas, y angosto paso llamado de la. Culebra, ha tenido que afrontar un tráfico creciente de navíos que siguen la evolución del tiempo. Para conseguir este paralelismo, tanto el material de explotación como la organización, dragados y mejoras, han tenido que conocer una sucesión ininterrumpida de modificaciones que han permitido

  16. 49 CFR 236.768 - Locking, time.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Locking, time. 236.768 Section 236.768... Locking, time. A method of locking, either mechanical or electrical, which, after a signal has been caused to display an aspect to proceed, prevents, until after the expiration of a predetermined time...

  17. 49 CFR 236.105 - Electric lock.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Electric lock. 236.105 Section 236.105 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION...: All Systems Inspections and Tests; All Systems § 236.105 Electric lock. Electric lock, except forced...

  18. 49 CFR 236.761 - Locking, electric.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Locking, electric. 236.761 Section 236.761 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Locking, electric. The combination of one or more electric locks and controlling circuits by means of...

  19. 49 CFR 236.757 - Lock, electric.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Lock, electric. 236.757 Section 236.757... Lock, electric. A device to prevent or restrict the movement of a lever, a switch or a movable bridge, unless the locking member is withdrawn by an electrical device, such as an electromagnet, solenoid or...

  20. 46 CFR 154.345 - Air locks.

    Science.gov (United States)

    2010-10-01

    ... mechanically ventilated to make the pressure in the space greater than that in the air lock; and (2) Has a... when the pressure in the space falls to or below the pressure in the air lock. ... a gas-safe space. (b) Each air lock must: (1) Consist of two steel doors, at least 1.5 m (4.9 ft...

  1. Bilateral locked facets in the thoracic spine

    NARCIS (Netherlands)

    M.H.A. Willems; Braakman, R. (Reinder); B. van Linge (Bert)

    1984-01-01

    textabstractTwo cases of traumatic bilateral locked facets in the thoracic spine are reported. Both patients had only minor neurological signs. They both made a full neurological recovery after surgical reduction of the locked facets. Bilateral locked facets are very uncommon in the thoracic spine.

  2. 46 CFR 108.157 - Locked doors.

    Science.gov (United States)

    2010-10-01

    ... may be designed to lock except— (a) A crash door or a door that has a locking device that can be... GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT... has control of the key to the door's lock. ...

  3. Locked jaw in polymyalgia rheumatica.

    Science.gov (United States)

    Lim, S H; McLeay, G

    1988-02-01

    Polymyalgia rheumatica is a common disease affecting the elderly population. Symptoms and signs are often nonspecific, including pain and stiffness in the proximal muscles, anorexia, fatigue, depression, weight loss, fever and temporal headaches. We would like to report a case of polymyalgia rheumatica with locked jaw, a feature yet unrecorded.

  4. Advances phase-lock techniques

    CERN Document Server

    Crawford, James A

    2008-01-01

    From cellphones to micrprocessors, to GPS navigation, phase-lock techniques are utilized in most all modern electronic devices. This high-level book takes a systems-level perspective, rather than circuit-level, which differentiates it from other books in the field.

  5. Short pulse generation in a passively mode-locked photonic crystal semiconductor laser

    DEFF Research Database (Denmark)

    Heuck, Mikkel; Blaaberg, Søren; Mørk, Jesper

    2010-01-01

    We present a new type of passively mode-locked laser with quantum wells embedded in photonic crystal waveguides operating in the slow light regime, which is capable of emitting sub picosecond pulses with widely controllable properties......We present a new type of passively mode-locked laser with quantum wells embedded in photonic crystal waveguides operating in the slow light regime, which is capable of emitting sub picosecond pulses with widely controllable properties...

  6. 49 CFR 236.766 - Locking, movable bridge.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Locking, movable bridge. 236.766 Section 236.766... Locking, movable bridge. The rail locks, bridge locks, bolt locks, circuit controllers, and electric locks used in providing interlocking protection at a movable bridge. ...

  7. Tidal locking of habitable exoplanets

    Science.gov (United States)

    Barnes, Rory

    2017-10-01

    Potentially habitable planets can orbit close enough to their host star that the differential gravity across their diameters can produce an elongated shape. Frictional forces inside the planet prevent the bulges from aligning perfectly with the host star and result in torques that alter the planet's rotational angular momentum. Eventually the tidal torques fix the rotation rate at a specific frequency, a process called tidal locking. Tidally locked planets on circular orbits will rotate synchronously, but those on eccentric orbits will either librate or rotate super-synchronously. Although these features of tidal theory are well known, a systematic survey of the rotational evolution of potentially habitable exoplanets using classic equilibrium tide theories has not been undertaken. I calculate how habitable planets evolve under two commonly used models and find, for example, that one model predicts that the Earth's rotation rate would have synchronized after 4.5 Gyr if its initial rotation period was 3 days, it had no satellites, and it always maintained the modern Earth's tidal properties. Lower mass stellar hosts will induce stronger tidal effects on potentially habitable planets, and tidal locking is possible for most planets in the habitable zones of GKM dwarf stars. For fast-rotating planets, both models predict eccentricity growth and that circularization can only occur once the rotational frequency is similar to the orbital frequency. The orbits of potentially habitable planets of very late M dwarfs ([InlineEquation not available: see fulltext.]) are very likely to be circularized within 1 Gyr, and hence, those planets will be synchronous rotators. Proxima b is almost assuredly tidally locked, but its orbit may not have circularized yet, so the planet could be rotating super-synchronously today. The evolution of the isolated and potentially habitable Kepler planet candidates is computed and about half could be tidally locked. Finally, projected TESS planets

  8. Tidal locking of habitable exoplanets

    Science.gov (United States)

    Barnes, Rory

    2017-12-01

    Potentially habitable planets can orbit close enough to their host star that the differential gravity across their diameters can produce an elongated shape. Frictional forces inside the planet prevent the bulges from aligning perfectly with the host star and result in torques that alter the planet's rotational angular momentum. Eventually the tidal torques fix the rotation rate at a specific frequency, a process called tidal locking. Tidally locked planets on circular orbits will rotate synchronously, but those on eccentric orbits will either librate or rotate super-synchronously. Although these features of tidal theory are well known, a systematic survey of the rotational evolution of potentially habitable exoplanets using classic equilibrium tide theories has not been undertaken. I calculate how habitable planets evolve under two commonly used models and find, for example, that one model predicts that the Earth's rotation rate would have synchronized after 4.5 Gyr if its initial rotation period was 3 days, it had no satellites, and it always maintained the modern Earth's tidal properties. Lower mass stellar hosts will induce stronger tidal effects on potentially habitable planets, and tidal locking is possible for most planets in the habitable zones of GKM dwarf stars. For fast-rotating planets, both models predict eccentricity growth and that circularization can only occur once the rotational frequency is similar to the orbital frequency. The orbits of potentially habitable planets of very late M dwarfs ([InlineEquation not available: see fulltext.]) are very likely to be circularized within 1 Gyr, and hence, those planets will be synchronous rotators. Proxima b is almost assuredly tidally locked, but its orbit may not have circularized yet, so the planet could be rotating super-synchronously today. The evolution of the isolated and potentially habitable Kepler planet candidates is computed and about half could be tidally locked. Finally, projected TESS planets

  9. Frequency of middle mesial canals in mandibular first molars in North Indian population - An in vivo study

    Directory of Open Access Journals (Sweden)

    Osama Adeel Khan Sherwani

    2016-01-01

    Full Text Available Objectives: The primary aim of the study was to determine the frequency of middle mesial (MM canals in mandibular first molars in North Indian population. The secondary aim was to analyze whether an association exists between the detection rate of MM canals and age, gender, and number of distal canals. Materials and Methods: All mature mandibular first molars endodontically treated between March 2013 and March 2015 were included in the study. After instrumenting the main canals, the clinician inspected the mesial developmental groove under dental operating microscope (DOM using ultrasonic tips and endodontic explorer to detect accessory mesial canals. The canal, if found, was negotiated, cleaned, shaped, and recorded. Results were analyzed using Chi-square test. Results: A total of 258 first molars from 243 patients were treated during the specified period, of which 28.3% had negotiable MM canals. The frequency of MM canals was 36.6% in patients 11-30 years old, 22.6% in patients 31-50 years old, and 18.4% in patients >50 years. Statistical analysis revealed a significant relationship of different age groups with the incidence of MM canals (P < 0.05. A significant relationship was also found between the detection rate of two canals in distal root and the presence of MM canals (P < 0.05 with gender having no influence. Conclusion: The presence of MM canals is quite high in North Indian population. Younger patients had a higher incidence of MM canals. Mandibular first molars with two separate distal canals showed a tendency to have MM canals.

  10. Reconfigurable Braille display with phase change locking

    Science.gov (United States)

    Soule, Cody W.; Lazarus, Nathan

    2016-07-01

    Automatically updated signs and displays for sighted people are common in today’s world. However, there is no cheap, low power equivalent available for the blind. This work demonstrates a reconfigurable Braille cell using the solid-to-liquid phase change of a low melting point alloy as a zero holding power locking mechanism. The device is actuated with the alloy in the liquid state, and is then allowed to solidify to lock the Braille dot in the actuated position. A low-cost manufacturing process is developed that includes molding of a rigid silicone to create pneumatic channels, and bonding of a thin membrane of a softer silicone on the surface for actuation. A plug of Field’s metal (melting point 62 °C) is placed in the pneumatic channels below each Braille dot to create the final device. The device is well suited for low duty cycle operation in applications such as signs, and is able to maintain its state indefinitely without additional power input. The display requires a pneumatic pressure of only 24 kPa for actuation, and reconfiguration has been demonstrated in less than a minute and a half.

  11. Pulse-spacing manipulation in a passively mode-locked multipulse fiber laser.

    Science.gov (United States)

    Yu, Ying; Wei, Xiaoming; Kang, Jiqiang; Li, Bowen; Wong, Kenneth K Y

    2017-06-12

    Passively mode-locked fiber lasers have been intensively applied in various research fields. However, the passive mode-locking typically operates in free-running regime, which easily produces messy multiple pulses due to the fruitful nonlinear effects involved in optical fibers. Actively controlling those disordered pulses in a passively mode-locked laser is of great interest but rarely studied. In this work, we experimentally investigate a flexible pulse-spacing manipulation in the passively mode-locked multipulse fiber laser by both intracavity and extracavity methods. A tuning range of pulse spacing up to 1.5 ns is achieved. More importantly, continuous pulse-spacing modulation is successfully demonstrated through external optical injection. It is anticipated that the results can contribute to the understanding of laser nonlinear dynamics and pursuing the optimal performance of passively mode-locked fiber lasers for practical applications.

  12. Phase locking of a semiconductor double-quantum-dot single-atom maser

    Science.gov (United States)

    Liu, Y.-Y.; Hartke, T. R.; Stehlik, J.; Petta, J. R.

    2017-11-01

    We experimentally study the phase stabilization of a semiconductor double-quantum-dot (DQD) single-atom maser by injection locking. A voltage-biased DQD serves as an electrically tunable microwave frequency gain medium. The statistics of the maser output field demonstrate that the maser can be phase locked to an external cavity drive, with a resulting phase noise L =-99 dBc/Hz at a frequency offset of 1.3 MHz. The injection locking range, and the phase of the maser output relative to the injection locking input tone are in good agreement with Adler's theory. Furthermore, the electrically tunable DQD energy level structure allows us to rapidly switch the gain medium on and off, resulting in an emission spectrum that resembles a frequency comb. The free running frequency comb linewidth is ≈8 kHz and can be improved to less than 1 Hz by operating the comb in the injection locked regime.

  13. Use of locking plate and screws for triple pelvic osteotomy.

    Science.gov (United States)

    Rose, Scott A; Bruecker, Ken A; Petersen, Steve W; Uddin, Nizam

    2012-01-01

    To evaluate the efficacy and complication rate associated with use of a purpose-specific locking triple pelvic osteotomy (LTPO) plate. Prospective study. Dogs (n = 9; 15 hips). Physical examination, plain film radiography, computed tomography (CT) of the pelvis, and coxofemoral arthroscopy were performed before unilateral triple pelvic osteotomy (TPO) or staged bilateral TPO. Radiographs were taken after each procedure and 3-5, 6-8, and ≥12 weeks postoperatively. Pelvic width was measured at 3 locations to evaluate pelvic canal narrowing. No screw loosening occurred. Complications occurred in only 1 hip (7%) where pullout of the locking plate-screw construct from the caudal iliac segment occurred because of a fracture of the cis-cortex; the dog made a full recovery after a salvage procedure. There was no significant reduction in the cranial pelvic width but a small reduction at the level of the acetabuli and ischiatic tuberosities was noted 3-5 weeks after the 2nd TPO. The LTPO plate was associated with a lower complication rate than previously reported for TPOs using Slocum canine pelvic osteotomy plates (CPOP) and warrants further investigation. Pullout of the caudal plate-screw construct is a complication specific to LTPO implants. Bicortical screw purchase is recommended to prevent fracture of the cis-cortex and implant pullout. © Copyright 2011 by The American College of Veterinary Surgeons.

  14. Workshop on gate valve pressure locking and thermal binding

    Energy Technology Data Exchange (ETDEWEB)

    Brown, E.J.

    1995-07-01

    The purpose of the Workshop on Gate Valve Pressure Locking and Thermal Binding was to discuss pressure locking and thermal binding issues that could lead to inoperable gate valves in both boiling water and pressurized water reactors. The goal was to foster exchange of information to develop the technical bases to understand the phenomena, identify the components that are susceptible, discuss actual events, discuss the safety significance, and illustrate known corrective actions that can prevent or limit the occurrence of pressure locking or thermal binding. The presentations were structured to cover U.S. Nuclear Regulatory Commission staff evaluation of operating experience and planned regulatory activity; industry discussions of specific events, including foreign experience, and efforts to determine causes and alleviate the affects; and valve vendor experience and recommended corrective action. The discussions indicated that identifying valves susceptible to pressure locking and thermal binding was a complex process involving knowledge of components, systems, and plant operations. The corrective action options are varied and straightforward.

  15. Water losses from irrigation canals evaluation: comparison among different methodologies

    Science.gov (United States)

    Clemente, Paolo; De Luca, Domenico Antonio; Antonella Dino, Giovanna; Lasagna, Manuela

    2013-04-01

    , especially for low canal discharge, because of the high instrumental error. A more rigorous method, based on the quantification of artificial tracers mass losses through exfiltration, was tested. This methodology is based on QUEST method (Rieckermann J. & Guier W., 2002; De Luca et alii, 2012). The used tracers were sodium chloride (NaCl), uranine and rhodamine WT. Uranine and rhodamine were detected by means of a fluorometer and NaCl thanks to a conductivimeter. In order to reduce the error of the NaCl detection, a multistage sampling in different parts of the cross section was applied, guaranteeing the contemporary water picking up. The results of these last tests were more accurate and in accordance with the aim of the research. References De Luca D. A., Comina C., Destefanis E., Marzano F., Carbotta G., Dino G., Passarella I., Masciocco L., Sambuelli L., Perotti L., Lasagna M., Clemente P., Bonetto S. (2012). Definizione di linee guida per la valutazione delle perdite dei canali irrigui. Convenzione scientifica tra Dipartimento di Scienze della Terra e Regione Piemonte - Direzione Agricoltura. Final Report. Rieckermann J., Gujer W. (2002) - Quantifying Exfiltration from Leaky Sewers with Artificial Tracers - Proceedings of the International Conference on "Sewer Operation and Maintenance. 2002", Bradford, UK.

  16. Widely tunable all-fiber SESAM mode-locked Ytterbium laser with a linear cavity

    Science.gov (United States)

    Zou, Feng; Wang, Zhaokun; Wang, Ziwei; Bai, Yang; Li, Qiurui; Zhou, Jun

    2017-07-01

    We present a widely tunable all-fiber mode-locked laser based on semiconductor saturable absorber mirror (SESAM) with a linear cavity design. An easy-to-use tunable bandpass filter based on thin film cavity technology is employed to tune the wavelength. By tuning the filter and adjusting the polarization controller, mode-locked operation can be achieved over the range of 1023 nm-1060 nm. With the polarization controller settled, mode-locked operation can be preserved and the wavelength can be continuously tuned from 1030 nm to 1053 nm. At 1030 nm, the laser delivers 9.6 mw average output power with 15.4 ps 10.96 MHz pulses at fundamental mode-locked operation.

  17. Dissipative soliton and synchronously dual-wavelength mode-locking Yb:YSO lasers.

    Science.gov (United States)

    Tian, Wenlong; Wang, Zhaohua; Liu, Jiaxing; Zhu, Jiangfeng; Zheng, Lihe; Xu, Xiaodong; Xu, Jun; Wei, Zhiyi

    2015-04-06

    We experimentally demonstrate the dissipative soliton mode-locking operation of a Yb:YSO laser by using an all-normal dispersion cavity. Strongly chirped pulses are obtained with pulse duration of 9.3 ps at a repetition rate of 113.4 MHz. The central wavelength is 1082 nm with 3.1 nm FWHM bandwidth. A dual-wavelength synchronously mode-locking operation at central wavelengths of 1059.2 nm and 1082.2 nm is also reported. Stable mode-locked pulses are achieved with pulse duration of 10 ps and total average output power of 164 mW. Periodic ultrashort beat pulses with pulse duration of 169 fs at an ultrahigh repetition rate of 1.4 THz can be distinctly observed from the measured autocorrelation trace. To our knowledge, this is the first demonstration of dual-wavelength synchronously mode-locking operation from a Yb:YSO laser.

  18. Optical Injection Locking of a VCSEL in an OEO

    Science.gov (United States)

    Strekalov, Dmitry; Matsko, Andrey; Savchenkov, Anatoliy; Yu, Nan; Maleki, Lute

    2009-01-01

    Optical injection locking has been demonstrated to be effective as a means of stabilizing the wavelength of light emitted by a vertical-cavity surface- emitting laser (VCSEL) that is an active element in the frequency-control loop of an opto-electronic oscillator (OEO) designed to implement an atomic clock based on an electromagnetically- induced-transparency resonance. This particular optical-injection- locking scheme is expected to enable the development of small, low-power, high-stability atomic clocks that would be suitable for use in applications involving precise navigation and/or communication. In one essential aspect of operation of an OEO of the type described above, a microwave modulation signal is coupled into the VCSEL. Heretofore, it has been well known that the wavelength of light emitted by a VCSEL depends on its temperature and drive current, necessitating thorough stabilization of these operational parameters. Recently, it was discovered that the wavelength also depends on the microwave power coupled into the VCSEL. Inasmuch as the microwave power circulating in the frequency-control loop is a dynamic frequency-control variable (and, hence, cannot be stabilized), there arises a need for another means of stabilizing the wavelength. The present optical-injection-locking scheme satisfies the need for a means to stabilize the wavelength against microwave- power fluctuations. It is also expected to afford stabilization against temperature and current fluctuations. In an experiment performed to demonstrate this scheme, wavelength locking was observed when about 200 W of the output power of a commercial tunable diode laser was injected into a commercial VCSEL, designed to operate in the wavelength range of 795+/-3 nm, that was generating about 200 microW of optical power. (The use of relatively high injection power levels is a usual practice in injection locking of VCSELs.)

  19. Ab interno Schlemm's Canal Surgery.

    Science.gov (United States)

    Francis, Brian A; Akil, Handan; Bert, Benjamin B

    2017-01-01

    In primary open-angle glaucoma, the site of greatest resistance to aqueous outflow is thought to be the trabecular meshwork (TM) and inner wall of Schlemm's canal. Augmentation of the conventional (trabecular) outflow pathway can facilitate physiologic outflow and subsequently lower intraocular pressure. The most recent approach to enhancing the conventional outflow pathway is via an internal approach to the TM and Schlemm's canal. Ab interno Schlemm's canal surgery includes 4 novel surgical approaches: (1) removal of the TM and inner wall of Schlemm's canal by an internal approach (ab interno trabeculectomy), (2) implantation of a microstent to bypass the TM, (3) disruption of the TM and inner wall of Schlemm's canal via an internal approach (ab interno trabeculotomy), and (4) dilation of Schlemm's canal via an internal approach (ab interno canaloplasty). The first category includes the Trabectome (Neomedix, Tustin, CA, USA), and Kahook Dual Blade (New World Medical, Rancho Cucamonga, CA, USA). The second category includes the iStent (Glaukos, Laguna Hills, CA, USA), as well as the investigational Hydrus Microstent implant (Ivantis, Irvine, CA, USA). The third category includes gonioscopic-assisted transluminal trabeculotomy (iSciences catheter; Ellex, Adelaide, Australia), and 360° suture trabeculotomy (TRAB360, Sight Sciences, Menlo Park, CA, USA). The fourth category includes ab interno canaloplasty or AbiC (Ellex), and Visco360 (Sight Sciences). In contrast to external filtration surgeries, such as trabeculectomy and aqueous tube shunt, these procedures are categorized as internal filtration surgeries and are performed from an internal approach via gonioscopic guidance. Published results suggest that these surgical procedures are both safe and efficacious for the treatment of open-angle glaucoma. © 2017 S. Karger AG, Basel.

  20. Locking devise for oil platforms

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, P.-A.; Naudin, J.-C.

    1987-10-20

    A self-raising oil well platform comprises a shell mounted to be movable along legs by means of raising mechanisms comprising output gear pinions cooperative with racks mounted on at least a part of the length of the legs. The locking device for such a platform comprises a toothed member forming a counter-rack mounted on the shell of the platform, means for shifting the toothed member transversely of the direction of the rack with which the device is associated for engaging or disengaging the teeth of the toothed member in the teeth of the rack, clamping plates connected to the toothed member and clamping counter-plates connected to the platform, and means for clamping the plates and counter-plates together so as to lock the toothed member in position in the rack. 4 figs.

  1. 10-GHz 1.59-μm quantum dash passively mode-locked two-section lasers

    DEFF Research Database (Denmark)

    Dontabactouny, Madhoussoudhana; Rosenberg, C.; Semenova, Elizaveta

    2010-01-01

    This paper reports the fabrication and the characterisation of a 10 GHz two-section passively mode-locked quantum dash laser emitting at 1.59 μm. The potential of the device's mode-locking is investigated through an analytical model taking into account both the material parameters and the laser...... geometry. Results show that the combination of a small absorbing section coupled to a high absorption coefficient can lead to an efficient mode-locking. Characterisation shows mode-locking operation though output pulses are found to be strongly chirped. Noise measurements demonstrate that the single side...

  2. Developmental spinal canal stenosis and somatotype.

    OpenAIRE

    Nightingale, S.

    1989-01-01

    The hypothesis that somatotype and cervical spine developmental canal stenosis may be associated has been investigated by anthropometry and measurement of lateral projection cervical spine radiographs. A significant association of canal size with somatotype has been found such that those with developmentally narrow canals are more likely to have relatively shorter long-bones, particularly in the upper arm, and longer trunks.

  3. Spectroscopic characteristics, continuous-wave and mode-locking laser performances of Tm,Y:CaF2 disordered crystal.

    Science.gov (United States)

    Kong, Lingchen; Qiao, Zhen; Xie, Guoqiang; Qin, Zhipeng; Zhao, Beibei; Yu, Hao; Su, Liangbi; Ma, Jingui; Yuan, Peng; Qian, Liejia

    2017-09-04

    The spectroscopic characteristics, continuous-wave (CW) and mode-locking laser performances of Tm,Y:CaF2 disordered crystal were studied. A maximum CW output power of 586 mW was obtained with a slope efficiency of 26%. The Tm,Y:CaF2 mode-locked laser could operate in two states: single-wavelength mode locking or dual-wavelength synchronous mode locking. The single-wavelength mode-locked laser generated pulses with pulse duration of 22 ps, repetition rate of 99 MHz, and pulse energy of 1.15 nJ at 1887 nm. Alternatively, the laser could also be mode-locked simultaneously at 1880.7 nm and 1889.0 nm wavelengths. The beating modulation in autocorrelation trace shows that the dual-wavelength pulses were temporally synchronous.

  4. Maxillary first molar with seven root canals diagnosed with cone-beam computed tomography scanning

    Directory of Open Access Journals (Sweden)

    Anil Munavalli

    2015-01-01

    Full Text Available Nonsurgical endodontic therapy of a right maxillary first molar with three roots and seven root canals. This unusual morphology was diagnosed using a dental operating microscope (DOM and confirmed with the help of cone-beam computed tomography (CBCT images. CBCT axial images showed that both the palatal and distobuccal root have a Vertucci type II canal pattern, whereas the mesiobuccal root showed a Sert and Bayirli type XVIII canal configuration. The use of a DOM and CBCT imaging in endodontically challenging cases can facilitate a better understanding of the complex root canal anatomy, which ultimately enables the clinician to explore the root canal system and clean, shape, and obturate it more efficiently.

  5. Erie Canal Technology: Stump Pullers

    Science.gov (United States)

    Greenslade, Thomas B., Jr.

    2013-01-01

    Many years ago I saw a picture of a huge set of wheels that was used to remove tree stumps during the construction of the Erie Canal (1817-1825) and was intrigued by its use of leverage, mechanical advantage, and torque. Figure 1 is a scale model of the device based on my memory of the (lost) picture and published accounts.

  6. Contemporary root canal filling strategies

    NARCIS (Netherlands)

    Moinzadeh, A.T.

    2016-01-01

    Currently, clinicians can choose from a wide range of root canal filling materials and techniques, some of which have been evaluated in this thesis. Methacrylate resin-based sealers suffer from polymerization shrinkage stresses. This limitation may partly be overcome by a two-step cementation

  7. Retention of Root Canal Posts

    DEFF Research Database (Denmark)

    Sahafi, A; Benetti, Ana Raquel; Flury, S

    2015-01-01

    ] and a self-etch adhesive resin cement [Panavia F2.0]) were used. After removal of the crowns of 360 extracted premolars, canines, or incisors, the root canals were prepared with a parallel-sided drill system to three different final diameters. Half the posts did not receive any pretreatment. The other half...

  8. Widely tunable Tm-doped mode-locked all-fiber laser.

    Science.gov (United States)

    Yan, Zhiyu; Sun, Biao; Li, Xiaohui; Luo, Jiaqi; Shum, Perry Ping; Yu, Xia; Zhang, Ying; Wang, Qi Jie

    2016-06-06

    We demonstrated a widely tunable Tm-doped mode-locked all-fiber laser, with the widest tunable range of 136 nm, from 1842 to 1978 nm. Nonlinear polarization evolution (NPE) technique is employed to enable mode-locking and the wavelength-tunable operation. The widely tunable range attributes to the NPE-induced transmission modulation and bidirectional pumping mechanism. Such kind of tunable mode-locked laser can find various applications in optical communications, spectroscopy, time-resolved measurement, and among others.

  9. Widely tunable Tm-doped mode-locked all-fiber laser

    Science.gov (United States)

    Yan, Zhiyu; Sun, Biao; Li, Xiaohui; Luo, Jiaqi; Shum, Perry Ping; Yu, Xia; Zhang, Ying; Wang, Qi Jie

    2016-01-01

    We demonstrated a widely tunable Tm-doped mode-locked all-fiber laser, with the widest tunable range of 136 nm, from 1842 to 1978 nm. Nonlinear polarization evolution (NPE) technique is employed to enable mode-locking and the wavelength-tunable operation. The widely tunable range attributes to the NPE-induced transmission modulation and bidirectional pumping mechanism. Such kind of tunable mode-locked laser can find various applications in optical communications, spectroscopy, time-resolved measurement, and among others. PMID:27263655

  10. Geology of the Chesapeake and Ohio Canal National Historical Park and Potomac River Corridor, District of Columbia, Maryland, West Virginia, and Virginia

    Science.gov (United States)

    Southworth, Scott; Brezinski, David K.; Orndorff, Randall C.; Repetski, John E.; Denenny, Danielle M.

    2008-01-01

    The Chesapeake and Ohio Canal National Historical Park is 184.5 mi long and extends from Washington, D.C., to Cumberland, Md. The canal passes through three physiographic provinces including the Piedmont, Valley and Ridge, and the Blue Ridge; the map area also includes rocks of the Coastal Plain and Appalachian Plateaus provinces. Each province contains unique packages of rocks that influenced the character of the canal and towpath. The ages of the bedrock encountered along the length of the park range from Mesoproterozoic to Jurassic and represent a variety of tectonic and depositional environments. The different rock types and surficial deposits dictated the various construction methods for the canal, which was excavated in Quaternary flood-plain deposits as well as through bedrock. The ancient course of the Potomac River and the deposits it left behind also influenced the location of the canal and towpath. The engineers made good use of the many rock types to construct the locks, dams, aqueducts, and culverts that guided water from the Potomac River into the canal and maintained the water level as canal boats traveled between higher elevations in western Maryland to sea level in Washington, D.C. The canal and towpath provide a unique transect across the central Appalachian region for examining the rich geologic diversity and history.

  11. Effect of magnification on locating the MB2 canal in maxillary molars.

    Science.gov (United States)

    Buhrley, Louis J; Barrows, Michael J; BeGole, Ellen A; Wenckus, Christopher S

    2002-04-01

    The purpose of this study was to determine if the surgical operating microscope and/or dental loupes could enhance the practitioner's ability to locate the second mesiobuccal canal (MB2) canal of maxillary molars in an in vivo, clinical setting. The participating endodontists documented 312 cases of root canal therapy on maxillary first and second molars. Participants that used the microscope or dental loupes located the MB2 canal with a frequency of 57.4% and 55.3%, respectively. Those using no magnification located the MB2 canal with a frequency of 18.2%. When no magnification was used, significantly fewer MB2 canals were located based by Chi-square analysis at p magnification groups was 71.1%, 62.5%, and 17.2%, respectively. The results of this study show that the use of magnification in combined groups leads to a MB2 detection rate approximately three times that of the nonmagnification group and that the use of no magnification results in the location of significantly fewer MB2 canals. Based on these results, more emphasis should be placed on the importance of using magnification for locating the MB2 canal.

  12. Optically-induced switching between mode-locked and unmode-locked continuous wave regimes of a femtosecond Cr4+:forsterite laser

    Science.gov (United States)

    Walsh, D. A.; Crombie, C. E.; Sibbett, W.; Brown, C. T. A.; Savitski, V. G.; Burns, D.; Calvez, S.

    2012-06-01

    The ability to control the temporal output from a femtosecond laser can enable the same laser to be used for multiple functions, for example, the laser used in an optical tweezers system could be used as a constant-intensity source to trap a biological cell and then be temporarily switched to mode-locked operation to effect photoporation. Here, we report the rapid switching of a Cr4+:forsterite laser between mode-locked and unmode-locked continuous wave (CW) regimes via the optical pumping of an intracavity SESAM element. Mode-locking of the laser was initiated by an intracavity quantum well (GaInAsN) SESAM having an anti-resonant design (ΔR~0.3%, λPL~1310nm) that yielded transform-limited 89fs pulses centered around 1296nm with a repetition rate of 162MHz at an average power of 64mW. Upon excitation of the SESAM with 600mW of extra-cavity power from an 808nm semiconductor diode laser, switching could be induced between the unmode-locked and mode-locked regimes. Transitions free of Q-switching or relaxation oscillations were observed with switching times for both for the initiation and cessation of mode-locking. Periods of mode-locked operation of custom duration could be produced by appropriate control of the SESAM pump diode enabling the generation of bursts of pulses as short as 400μs. Switching was confirmed to originate from local pump-induced heating of the SESAM by observing the laser going through identical regime switching when the chip temperature of the 'unpumped' SESAM was raised by ~20°C.

  13. High power L-band mode-locked fiber laser based on topological insulator saturable absorber.

    Science.gov (United States)

    Meng, Yichang; Semaan, Georges; Salhi, Mohamed; Niang, Alioune; Guesmi, Khmaies; Luo, Zhi-Chao; Sanchez, Francois

    2015-09-07

    We demonstrate a passive mode-locked Er:Yb doped double-clad fiber laser using a microfiber-based topological insulator (Bi(2)Se(3)) saturable absorber (TISA). By optimizing the cavity loss and output coupling ratio, the mode-locked fiber laser can operate in L-band with high average output power. With the highest pump power of 5 W, 91st harmonic mode locking of soliton bunches with average output power of 308 mW was obtained. This is the first report that the TISA based erbium-doped fiber laser operating above 1.6 μm and is also the highest output power yet reported in TISA based passive mode-locked fiber laser.

  14. Mandibular Second Premolar with Four Canals

    Directory of Open Access Journals (Sweden)

    Javad Ghiasi

    2015-09-01

    Full Text Available A mandibular second premolar with four canals is an interesting example of anatomic variations. This report describes a case of a mandibular second premolar with three roots and four canals (one mesiobuccal, two distobuccal and one lingual. The canals were prepared using K-files and irrigated with NaOCl (5.25% and normal saline as the final irrigant. The canals were filled laterally with gutta percha and AH26 sealer (De Trey, Dentsply, Switzerland. This case shows a rare anatomic configuration and points out the importance of looking for additional canals.

  15. Linear coherent receiver based on a broadband and sampling optical phase-locked loop

    DEFF Research Database (Denmark)

    Bowers, J.E.; Ramaswamy, A.; Johansson, L.A.

    2007-01-01

    A novel coherent receiver for linear optical phase demodulation is proposed and experimentally demonstrated. The receiver, based on a broadband optical phase-lock loop has a bandwidth of 1.45 GHz. Using the receiver in an analog link experiment, a spurious free dynamic range of 125 dBHz2....../3 is measured at 300 MHz. Further, theoretical investigations are presented demonstrating receiver operation at high frequencies (>2 GHz) using a sampling phase-locked loop....

  16. Phase-locked Josephson soliton oscillators

    DEFF Research Database (Denmark)

    Holst, T.; Hansen, Jørn Bindslev; Grønbech-Jensen, N.

    1991-01-01

    Detailed experimental characterization of the phase-locking at both DC and at microwave frequencies is presented for two closely spaced Josephson soliton (fluxon) oscillators. In the phase-locked state, the radiated microwave power exhibited an effective gain. With one common bias source......, a frequency tunability of the phase-locked oscillators up to 7% at 10 GHz was observed. The interacting soliton oscillators were modeled by two inductively coupled nonlinear transmission lines...

  17. Mode-locked deep ultraviolet Ce:LiCAF laser.

    Science.gov (United States)

    Granados, Eduardo; Coutts, David W; Spence, David J

    2009-06-01

    We report mode-locked operation of a synchronously pumped Ce:LiCAF oscillator. The laser operated in the deep UV with output radiation centered at 291 nm and a pulse duration of 6 ps. The maximum output power measured was 52 mW, with 13% slope efficiency. The Ce:LiCAF crystal has a gain bandwidth capable of supporting few-femtosecond pulses, and so our results demonstrate the potential to form a new class of ultrafast lasers operating directly at deep UV wavelengths.

  18. Phase locking between Josephson soliton oscillators

    DEFF Research Database (Denmark)

    Holst, T.; Hansen, Jørn Bindslev; Grønbech-Jensen, N.

    1990-01-01

    We report observations of phase-locking phenomena between two Josephson soliton (fluxon) oscillators biased in self-resonant modes. The locking strength was measured as a function of bias conditions. A frequency tunability of the phase-locked oscillators up to 7% at 10 GHz was observed. Two coupled...... perturbed sine-Gordon equations were derived from an equivalent circuit consisting of inductively coupled, nonlinear, lossy transmission lines. These equations were solved numerically to find the locking regions. Good qualitative agreement was found between the experimental results and the calculations...

  19. Microcontroller-based locking in optics experiments.

    Science.gov (United States)

    Huang, K; Le Jeannic, H; Ruaudel, J; Morin, O; Laurat, J

    2014-12-01

    Optics experiments critically require the stable and accurate locking of relative phases between light beams or the stabilization of Fabry-Perot cavity lengths. Here, we present a simple and inexpensive technique based on a stand-alone microcontroller unit to perform such tasks. Easily programmed in C language, this reconfigurable digital locking system also enables automatic relocking and sequential functioning. Different algorithms are detailed and applied to fringe locking and to low- and high-finesse optical cavity stabilization, without the need of external modulations or error signals. This technique can readily replace a number of analog locking systems advantageously in a variety of optical experiments.

  20. Field Experience with Lock Culvert Valves

    Science.gov (United States)

    2013-12-01

    interesting accounts regarding their lock culvert valves. ST. LAWRENCE SEAWAY Eisenhower and Snell Locks. The valves on the Eisenhower and Snell Locks...Tainter Valve Design Lift, ft Eisenhower St. Lawrence Seaway 80 x 860 12 x 14 21.0 DSP 43 Snell St. Lawrence Seaway 80 x 860 12 x 14 21.0 3 DSP, 1 VF 49...vertical-frame valves were furnished to the SLSDC in January 2011, and one was installed in the south filling-valve location at Snell Lock. An option

  1. 75 FR 39632 - Regulated Navigation Area; Gulf Intracoastal Waterway, Inner Harbor Navigation Canal, Harvey...

    Science.gov (United States)

    2010-07-12

    ..., Inner Harbor Navigation Canal, Harvey Canal, Algiers Canal, New Orleans, LA; Correction ACTION: Interim... Navigation Canal, Harvey Canal, Algiers Canal, New Orleans, LA into the Code of Federal Regulations. That...

  2. Self-mode-locked AlGaInP-VECSEL

    Science.gov (United States)

    Bek, R.; Großmann, M.; Kahle, H.; Koch, M.; Rahimi-Iman, A.; Jetter, M.; Michler, P.

    2017-10-01

    We report the mode-locked operation of an AlGaInP-based semiconductor disk laser without a saturable absorber. The active region containing 20 GaInP quantum wells is used in a linear cavity with a curved outcoupling mirror. The gain chip is optically pumped by a 532 nm laser, and mode-locking is achieved by carefully adjusting the pump spot size. For a pump power of 6.8 W, an average output power of up to 30 mW is reached at a laser wavelength of 666 nm. The pulsed emission is characterized using a fast oscilloscope and a spectrum analyzer, demonstrating stable single-pulse operation at a repetition rate of 3.5 GHz. Intensity autocorrelation measurements reveal a FWHM pulse duration of 22 ps with an additional coherence peak on top, indicating noise-like pulses. The frequency spectrum, as well as the Gaussian beam profile and the measured beam propagation factor below 1.1, shows no influence of higher order transverse modes contributing to the mode-locked operation.

  3. Prevalence of middle mesial canals in mandibular molars after guided troughing under high magnification: an in vivo investigation.

    Science.gov (United States)

    Azim, Adham A; Deutsch, Allan S; Solomon, Charles S

    2015-02-01

    A limited number of in vivo studies have discussed the prevalence of middle mesial canals in root canal systems of mandibular molars. The reported results have varied between 1% and 25%, with no detailed description of the depth and direction of troughing needed to identify such small canal orifices. The objective of the present study was to determine (1) the prevalence of a middle mesial canal before and after troughing by using a standardized troughing technique, (2) the pathway of the middle mesial canal in relation to the mesiobuccal (MB) and mesiolingual (ML) canals, and (3) its correlation with the patient's age. Ninety-one mandibular molars from 87 patients were included in this study. The patient's age and tooth number were recorded. After access cavity preparation, a standardized troughing technique was performed between MB and ML canals to search for a middle mesial canal by using a dental operating microscope. If a middle mesial canal was located, it was recorded as separate or as joining the MB or the ML canals. Results were statistically analyzed by using Z test and logistic regression. A middle mesial canal was found in 42 of 91 mandibular molars (46.2%). Six middle mesial canals were located after conventional access preparation (6.6%). The other 36 were located after standardized troughing (39.6%). The results were statistically significant (P magnification, troughing, and patient's age appeared to be determining factors in accessing the middle mesial canal. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  4. A Type System for Unstructured Locking that Guarantees Deadlock Freedom without Imposing a Lock Ordering

    Directory of Open Access Journals (Sweden)

    Prodromos Gerakios

    2011-10-01

    Full Text Available Deadlocks occur in concurrent programs as a consequence of cyclic resource acquisition between threads. In this paper we present a novel type system that guarantees deadlock freedom for a language with references, unstructured locking primitives, and locks which are implicitly associated with references. The proposed type system does not impose a strict lock acquisition order and thus increases programming language expressiveness.

  5. «Réception de Locke au Danemark: Holberg, lecteur de Locke»

    DEFF Research Database (Denmark)

    Schøsler, Jørn

    Der gives en analyse af Holbergs læsning af Locke i Moralske Tanker og Epistler. Der fokuseres på hans holdning til Locke's Essay, hvor han synes fascineret af 'hypotesen om den tænkende materie' og problemet om de 'medfødte ideer'. Han tilslutter sig Locke's empirisme, men forsvarer dog en medfødt...

  6. Unusual Cause of Knee Locking

    OpenAIRE

    Huri, Gazi; Bi?er, Omer Sunkar

    2013-01-01

    We report a case of partial intrasubstance tear of popliteus tendon as an unusual cause of pseudolocking of the knee. A 13-year-old semiprofessional soccer player applied to our clinic with a locked right knee in spite of the therapy applied (cold pack, NSAID, and immobilization) in another institution 20 days after the injury. Significant extension loss was observed in his right knee with 30∘–90∘ ROM. Magnetic resonance imaging (MRI) and arthroscopy confirmed the intrasubstance tear of popli...

  7. Coupled optical resonance laser locking

    CSIR Research Space (South Africa)

    Burd, CC

    2014-10-01

    Full Text Available . The coupled resonance technique discussed here overcomes this obstacle, and works as follows. If the 2S1/2 → 2P1/2 transition is driven at resonance, there will be a net increase of ions in the 2D3/2 state and a decrease in the population of ions in the ground... stream_source_info Burd_2014.pdf.txt stream_content_type text/plain stream_size 31258 Content-Encoding UTF-8 stream_name Burd_2014.pdf.txt Content-Type text/plain; charset=UTF-8 Coupled optical resonance laser locking S...

  8. Development and evaluation of a tutorial to improve students’ understanding of a lock-in amplifier

    Directory of Open Access Journals (Sweden)

    Seth DeVore

    2016-09-01

    Full Text Available A lock-in amplifier is a versatile instrument frequently used in physics research. However, many students struggle with the basic operating principles of a lock-in amplifier which can lead to a variety of difficulties. To improve students’ understanding, we have been developing and evaluating a research-based tutorial which makes use of a computer simulation of a lock-in amplifier. The tutorial is based on a field-tested approach in which students realize their difficulties after predicting the outcome of simulated experiments involving a lock-in amplifier and check their predictions using the simulated lock-in amplifier. Then, the tutorial provides guidance and strives to help students develop a coherent understanding of the basics of a lock-in amplifier. The tutorial development involved interviews with physics faculty members and graduate students and iteration of many versions of the tutorial with professors and graduate students. The student difficulties with lock-in amplifiers and the development and evaluation of the research-based tutorial to help students develop a functional understanding of this device are discussed.

  9. Intermode beating mode-locking technique for a rare-earth-doped fiber pulsed laser.

    Science.gov (United States)

    Luo, Zhengqian; Yang, Runhua; Du, Tuanjie; Ruan, Qiujun; Li, Weiwei; Chen, Nan

    2017-08-01

    In this paper, we report the intermode beating mode-locking of a 2  μm Tm 3+ -doped fiber laser (TDFL) pumped by a 1565 nm continuous-wave multi-longitudinal-mode laser. Because strong intermode beating of the 1565 nm pump source induces the periodic modulation of 2 μm intracavity power, stable mode-locking of the TDFL is successfully established by precisely matching the 2 μm cavity frequency with the intermode-beating frequency of the 1565 nm pump source. The mode-locked laser, without requiring any specific mode-locking element, can stably emit the rectangular nanosecond pulses. The mode-locking operation at the center wavelength of 1980.35 nm has a >61  dB signal-to-noise ratio and a 34.496 MHz repetition rate. Although the preliminary results are not better than those of conventional mode-locking, intermode beating mode-locking in combination with rare-earth-doped fiber lasers could provide a promising and alternative solution for compact, low-cost, and high-performance pulsed laser sources.

  10. [Tomography of the pterygoid canals].

    Science.gov (United States)

    Riazantsev, S V; Kalenov, V E; Russkikh, N A

    1990-01-01

    This paper presents an X-ray scheme for calculating the depth of pterygoid canals required for accurate tomography. The scheme includes three lines: line A corresponds to the physiological horizontal line, line B is drawn, normally to line A through the tip of the nose, and line C is the perpendicular from line B to the upper third of the posterior wall of the pterygopalatine fossa. The length of line B plus 1 cm (thickness of external nose soft tissues) is the value to be determined. Twenty-six patients underwent X-ray examinations by an EDK-750B unit (70 kV, 150 mA, 1.65 s). In all cases 1-3 images were sufficient to obtain good visualization of the pterygoid canals.

  11. [Latest treatment of lumbar canal stenosis].

    Science.gov (United States)

    Kim, Kyongsong; Isu, Toyohiko

    2009-06-01

    Lumbar canal stenosis (LCS) is a degenerative disease involving the lumbar vertebrae, discs, and ligamentum flavum that result in neurological deficit to some extent. The natural history of symptoms of LCS is highly important because they do not necessarily worsen with progressive degeneration. Therefore, a observation therapy is adopted for the treatment of this condition. Although invasive treatment is required for some patients, surgery cannot be performed solely on the basis of radiological findings and careful evaluation of neurological symptoms is necessary. In the event that spinal surgery is required, it is important to minimize degree of invasiveness; various devices and operative approaches and methods have been developed to this end. Our strategy for the surgical treatment of LCS involves microscopic decompression via a posterior approach. In our method, modified bilateral decompression via the splitting of the spinous process using an ultrasonic bone curette (SONOPET), and the results of this approach have been excellent. Our method is less invasive, facilitates the preservation of the paraspinal muscle, and represents a useful approach to posterior spinal elements. Our findings indicate that this method involves less muscle damage as compared to other methods. LCS should be differentiated from conditions other than those involving the spinal canal such as foraminal stenosis and far-out syndrome, piriformis syndrome, and tarsal tunnel syndrome. The incidence of these conditions is higher than appreciated and they present with neurological deficits similar to observed in LCS. Here, we report our criteria of operative indications for surger and the procedures that we developed for the treatment of LCS, based on a review of the available literature.

  12. Scalloping at the lumbosacral canal

    Energy Technology Data Exchange (ETDEWEB)

    Reinhardt, R.

    1987-07-01

    Scalloping is an indentation of the dorsal side of the vertebral body (anterior wall of the lumbosacral or sacral canal) which typically involves several adjacent lumbal vertebral body segments and the anterior wall of the canalis sacralis. Occurrence without underlying disease is rare; it occurs most frequently with chondrodystrophy, neurofibromatosis, Morquio's syndrome, Hurler's syndrome, acromegaly, Ehlers-Danlos syndrome, Marfan's syndrome, cysts, tumors and in peridural lipomas.

  13. Endometriosis en el canal inguinal

    OpenAIRE

    Quirós, José Luis; Corrales, Daniela

    2013-01-01

    Resumen: Endometriosis se define como la presencia de tejido glandular y estromal endometrial fuera de la cavidad uterina y este tejido ectópico es dependiente de la estimulación estrogénica. Usualmente se presenta en ovarios, fondos de saco, ligamento ancho, ligamento uterosacro, útero, trompas de Falopio, tracto gastrointestinal y geniturinario. Sin embargo, puede presentarse en otras localizaciones, como en el canal inguinal. Prevalece en 10% de las mujeres en edad reproductiva. Existen mu...

  14. Microbiology of normal external auditory canal.

    Science.gov (United States)

    Stroman, D W; Roland, P S; Dohar, J; Burt, W

    2001-11-01

    To isolate and characterize bacteria and fungi from the healthy ear and to obtain susceptibility profiles on each bacterial isolate. Prospective. Specimens were collected from the external canals and cerumen of healthy subjects. Species-level identification was obtained by combining phenotypic and genotypic data. End-point minimal inhibitory concentration testing was performed using National Committee for Clinical Laboratory Standards recommended methods. One hundred sixty-four subjects were cultured. Seventeen canal and 16 cerumen specimens showed no growth. One hundred forty-eight cerumen specimens yielded 314 organisms, including 23 fungi. One hundred forty-seven canal specimens yielded 310 organisms, including 7 fungi. Of 291 bacteria isolated from cerumen, 99% were Gram-positive. Of 302 bacteria isolated from the canal, 96% were Gram-positive. Staphylococci were 63% of both the cerumen bacteria and the canal bacteria. Coryneforms represented 22% of the bacteria in cerumen and 19% in the canal. Turicellaotitidis was the primary coryneform isolated from both the canal and the cerumen. Streptococci-like bacteria were 10% from the cerumen, 7% from the canal. In both cerumen and canal, Alloiococcusotitis was more than 95% of the streptococci-like bacteria. Fifteen gram-negative organisms were isolated from the canal and cerumen, including four Pseudomonas aeruginosa strains. The percentages of Staphylococcus epidermidis isolates that had high-level resistance (> or =8 microg/mL) were as follows: to neomycin, 28% from cerumen and 11% from the canal; to oxacillin, 28% from cerumen and 25% from the canal; and to ofloxacin, 15% from cerumen and 19% from the canal. Turcellaotitidis and A. otitidis were present with a much higher frequency than previously described, lending evidence that they be considered normal otic flora. Corynebacterium auris, previously reported only in children, was isolated from normal adults.

  15. Multivariate analysis of the cleaning efficacy of different final irrigation techniques in the canal and isthmus of mandibular posterior teeth

    Directory of Open Access Journals (Sweden)

    Yeon-Jee Yoo

    2013-08-01

    Full Text Available Objectives The aim of this study was to compare the cleaning efficacy of different final irrigation regimens in canal and isthmus of mandibular molars, and to evaluate the influence of related variables on cleaning efficacy of the irrigation systems. Materials and Methods Mesial root canals from 60 mandibular molars were prepared and divided into 4 experimental groups according to the final irrigation technique: Group C, syringe irrigation; Group U, ultrasonics activation; Group SC, VPro StreamClean irrigation; Group EV, EndoVac irrigation. Cross-sections at 1, 3 and 5 mm levels from the apex were examined to calculate remaining debris area in the canal and isthmus spaces. Statistical analysis was completed by using Kruskal-Wallis test and Mann-Whitney U test for comparison among groups, and multivariate linear analysis to identify the significant variables (regular replenishment of irrigant, vapor lock management, and ultrasonic activation of irrigant affecting the cleaning efficacy of the experimental groups. Results Group SC and EV showed significantly higher canal cleanliness values than group C and U at 1 mm level (p < 0.05, and higher isthmus cleanliness values than group U at 3 mm and all levels of group C (p < 0.05. Multivariate linear regression analysis demonstrated that all variables had independent positive correlation at 1 mm level of canal and at all levels of isthmus with statistical significances. Conclusions Both VPro StreamClean and EndoVac system showed favorable result as final irrigation regimens for cleaning debris in the complicated root canal system having curved canal and/or isthmus. The debridement of the isthmi significantly depends on the variables rather than the canals.

  16. Construct Choice for the Treatment of Displaced, Comminuted Olecranon Fractures: are Locked Plates Cost Effective?

    Science.gov (United States)

    DelSole, Edward M; Egol, Kenneth A; Tejwani, Nirmal C

    2016-01-01

    Cost effective implant selection in orthopedic trauma is essential in the current era of managed healthcare delivery. Both locking and non-locking plates have been utilized in the treatment of displaced fractures of the olecranon. However, locking plates are often more costly and may not provide superior clinical outcomes. The primary aim of the present study is to assess the clinical and functional outcomes of olecranon fractures treated with locked and non-locking plate and screw constructs while providing insight into the cost of various implants. We performed a retrospective chart review of a single institution database identifying Mayo IIB type olecranon fractures treated surgically from 2003 to 2012. All fractures were treated with either a locked plate or a one-third tubular hook plate construct. Clinical and radiographic outcomes were evaluated. Minimum 6-month follow-up was required. Outcomes were compared between fixation constructs, including rate of union, early failure, postoperative range of motion, and complication rates. Statistical analysis included Pearson's Chi-squared and Fisher's exact test for categorical variables, and the Student's ttest for continuous variables. The one-third tubular construct was equivalent to locking plate constructs with respect to union, post-operative range of motion, and rates of complications. There were no early or late failures. Locking plates were associated with a relative cost increase of $1,263.50 compared to the one-third tubular hook plate per case. Surgeons should consider the cost of implants when treating Mayo IIB olecranon fracture. In this cohort, one-third tubular plates provided equivalent outcomes to locked plates with a notable decrease in cost.

  17. Lumbar spinal canal MRI diameter is smaller in herniated disc cauda equina syndrome patients

    OpenAIRE

    Korse, Nina S.; Kruit, Mark C.; Peul, Wilco C.; Vleggeert-Lankamp, Carmen L. A.

    2017-01-01

    Introduction Correlation between magnetic resonance imaging (MRI) and clinical features in cauda equina syndrome (CES) is unknown; nor is known whether there are differences in MRI spinal canal size between lumbar herniated disc patients with CES versus lumbar herniated discs patients without CES, operated for sciatica. The aims of this study are 1) evaluating the association of MRI features with clinical presentation and outcome of CES and 2) comparing lumbar spinal canal diameters of lumbar...

  18. Hydrological effects of tropical land use management incentives: Panama Canal Watershed

    Science.gov (United States)

    Fred Ogden; Jefferson S. Hall; Holly Barnard; Robert F. Stallard; Ell Fenichel; Vic Adamowicz; Brent Ewers; Ed Kempema; Julian Zhu

    2016-01-01

    Panama lies in the seasonal tropics and over 85 percent of annual precipitation falls during the May-December wet season. Extreme rainfall events near the end of the wet season can produce flooding that impact Panama Canal operations. During the December-April dry season, occasional water shortages limit the draft of ships passing through the Panama Canal, as well as...

  19. MEASUREMENT OF ROOT CANAL LENGTH – USE OF AN ELECTROMETRIC DEVICE

    OpenAIRE

    ANAND, SC; KHATTAK, BP; SACHDEVA, VP; CHETAL, BR

    1994-01-01

    The measurement of root canal length is a pre-requisite for successful pulpectomy. The conventional manual and radiographic methods are not very accurate. In the present study, odontometer was used [Group B) to assess its efficacy over the conventional methods (Group A) for recording root canal length. In group A, 36 teeth were treated with pulpectomy while in group B, 51 teeth were managed by the same treatment. It was observed that post operative complications in group B were significantly ...

  20. Express consent and full membership in Locke

    NARCIS (Netherlands)

    den Hartogh, G.A.

    1990-01-01

    It seems mysterious why Locke required express consent as a condition of full membership of civil society. It is suggested this requirement be interpreted as a political programme. In a draft of a pamphlet of 1690 Locke criticizes the oath of allegiance required after the Glorious Revolution for not

  1. Past, Present, Future Erosion at Locke Island

    Energy Technology Data Exchange (ETDEWEB)

    Bjornstad, Bruce N.

    2006-08-08

    This report describes and documents the erosion that has occurred along the northeast side of Locke Island over the last 10 to 20 years. The principal cause of this erosion is the massive Locke Island landslide complex opposite the Columbia River along the White Bluffs, which constricts the flow of the river and deflects the river's thalweg southward against the island.

  2. Phase-locking transition in Raman combs generated with whispering gallery mode resonators.

    Science.gov (United States)

    Lin, Guoping; Chembo, Yanne K

    2016-08-15

    We investigate the mechanisms leading to phase locking in Raman optical frequency combs generated with ultrahigh Q crystalline whispering gallery mode disk resonators. We show that several regimes can be triggered depending on the pumping conditions, such as single-frequency Raman lasing, multimode operation involving more than one family of cavity eigenmodes, and Kerr-assisted Raman frequency comb generation. The phase locking and coherence of the combs are experimentally monitored through the measurement of beat signal spectra. These phase-locked combs, which feature high coherence and wide spectral spans, are obtained with pump powers in the range of a few tens of mW. In particular, Raman frequency combs with multiple free-spectral range spacings are reported, and the measured beat signal in the microwave domain features a 3 dB linewidth smaller than 50 Hz, thereby indicating phase locking.

  3. Subharmonic anti-phase dynamics in coupled mode-locked semiconductor lasers.

    Science.gov (United States)

    Sivaramakrishnan, Sudarshan; Winful, Herbert G

    2017-12-01

    We show that coupled mode-locked semiconductor lasers can operate in a subharmonic regime in which the two lasers pulsate in an anti-phase manner at one-half the fundamental mode-locking frequency of the solitary lasers. In the subharmonic mode, each pulse has almost twice the energy carried by the isolated lasers in the fundamental mode-locked regime and is also significantly shorter in duration. Depending on the unsaturated gain and coupling strength, the lasers can also exhibit bistability, perfect synchronization, and delayed synchronization, as well as three-halves and five-halves harmonic mode locking. The observed behaviors are robust and persist in the presence of noise.

  4. Pulse dynamics in carbon nanotube mode-locked fiber lasers near zero cavity dispersion.

    Science.gov (United States)

    Wang, Jinzhang; Cai, Zhiping; Xu, Ping; Du, Geguo; Wang, Fengqiu; Ruan, Shuangchen; Sun, Zhipei; Hasan, Tawfique

    2015-04-20

    We numerically and experimentally analyze the output characteristics and pulse dynamics of carbon nanotube mode-locked fiber lasers near zero cavity dispersion (from 0.02 to ~-0.02 ps(2)). We focus on such near zero dispersion cavities to reveal the dispersion related transition between different mode-locking regimes (such as soliton-like, stretched-pulse and self-similar regimes). Using our proposed model, we develop a nanotube-mode-locked fiber laser setup generating ~97 fs pulse which operates in the stretched-pulse regime. The corresponding experimental results and pulse dynamics are in good agreement with the numerical results. Also, the experimental results from soliton-like and self-similar regimes exhibit the same trends with simulations. Our study will aid design of different mode-locking regimes based on other new saturable absorber materials to achieve ultra-short pulse duration.

  5. Commonwealth Edison Company pressure locking test report

    Energy Technology Data Exchange (ETDEWEB)

    Bunte, B.D.; Kelly, J.F.

    1996-12-01

    Pressure Locking is a phenomena which can cause the unseating thrust for a gate valve to increase dramatically from its typical static unseating thrust. This can result in the valve actuator having insufficient capability to open the valve. In addition, this can result in valve damage in cases where the actuator capability exceeds the valve structural limits. For these reasons, a proper understanding of the conditions which may cause pressure locking and thermal binding, as well as a methodology for predicting the unseating thrust for a pressure locked or thermally bound valve, are necessary. This report discusses the primary mechanisms which cause pressure locking. These include sudden depressurization of piping adjacent to the valve and pressurization of fluid trapped in the valve bonnet due to heat transfer. This report provides a methodology for calculating the unseating thrust for a valve which is pressure locked. This report provides test data which demonstrates the accuracy of the calculation methodology.

  6. Towards self-mode locking of AlGaInP-VECSELs (Conference Presentation)

    Science.gov (United States)

    Bek, Roman; Duong-Ederer, Quynh; Vaupel, Max; Kahle, Hermann; Schwarzbäck, Thomas; Rahimi-Iman, Arash; Jetter, Michael; Koch, Martin; Michler, Peter

    2017-03-01

    Since 2000, semiconductor saturable absorber mirrors (SESAMs) have been used to realize mode locking of vertical external-cavity surface-emitting lasers (VECSELs), achieving femtosecond pulse durations, GHZ repetition rates and several Watts of average output power. Despite these excellent results, SESAMs which have to be carefully adjusted to the gain structure can be a limiting factor for the development of a cost-effective pulsed laser system. In recent years, a new concept of VECSEL mode locking, the self-mode locking technique, has been demonstrated. While the mechanism behind this kind of mode locking is not yet fully explained, most publications focus on the effect of Kerr lensing. We present first experiments on SESAM-free mode locking of red-emitting AlGaInP-VECSELs with different cavity geometries based on the assumption of Kerr lensing in the active region. Our semiconductor samples are grown by metal-organic vapor-phase epitaxy with an active region containing GaInP quantum wells embedded in AlGaInP barriers and cladding layers. In order to exploit the effect of Kerr lensing, a slit is placed inside the cavity acting as a hard aperture. When the beam width is confined, pulsed operation is observed by oscilloscope and autocorrelation measurements. Ongoing research is focusing on a detailed characterization of the pulsed laser to improve one's understanding of the obtained SESAM-free mode-locked operation.

  7. Semiconductor Mode-Locked Lasers for Optical Communication Systems

    DEFF Research Database (Denmark)

    Yvind, Kresten

    2003-01-01

    The thesis deals with the design and fabrication of semiconductor mode-locked lasers for use in optical communication systems. The properties of pulse sources and characterization methods are described as well as requirements for application in communication systems. Especially, the importance of...... as the first 10 GHz all-active monolithic laser with both short pulses and low jitter.Results from external cavity mode-locked lasers are also reported along with an investigation of the influence of the operating conditions on the performance of the device. Antireflection coatings are a critical limiting...... factor for external cavity devices and a chapter is devoted to calculations on coating design.The fabrication process for the lasers is outlined and solutions to the challenges encountered in realizing the proposed structures are reported....

  8. Freshwater Mussels in the Lower Ohio River in Relation to the Olmsted Locks and Dam Project: Update Through 2001 Studies

    National Research Council Canada - National Science Library

    Payne, Barry

    2002-01-01

    ... of nonindigenous populations of freshwater bivalves in the lower Ohio River. Data will be used to analyze ecological effects of construction and operation of a new lock and dam at River Mile (RM) 964.4...

  9. Status of Freshwater Mussels in the Lower Ohio River in Relation to the Olmsted Locks and Dam Project: 1999 Studies

    National Research Council Canada - National Science Library

    Payne, Barry

    2001-01-01

    ... of nonindigenous populations of freshwater bivalves in the lower Ohio River (LOR). Data will be used to analyze ecological effects of construction and operation of a new lock and dam at River Mile (RM) 964.4...

  10. 76 FR 67167 - Riverbank Hydro No. 1 LLC; Qualified Hydro 20 LLC; Lock Hydro Friends Fund XXXVII; Notice of...

    Science.gov (United States)

    2011-10-31

    ...-000 would consist of: (1) One lock frame module, the frame module will be 44-feet long, 40-feet-high... distribution line. The proposed project would have an average annual generation of 43.830 GWh and operate run...

  11. Endodontic treatment of a C-shaped mandibular second premolar with four root canals and three apical foramina: a case report

    Directory of Open Access Journals (Sweden)

    Thikamphaa Bertrand

    2016-02-01

    Full Text Available This case report describes a unique C-shaped mandibular second premolar with four canals and three apical foramina and its endodontic management with the aid of cone-beam computer tomography (CBCT. C-shaped root canal morphology with four canals was identified under a dental operating microscope. A CBCT scan was taken to evaluate the aberrant root canal anatomy and devise a better instrumentation strategy based on the anatomy. All canals were instrumented to have a 0.05 taper using 1.0 mm step-back filing with appropriate apical sizes determined from the CBCT scan images and filled using a warm vertical compaction technique. A C-shaped mandibular second premolar with multiple canals is an anatomically rare case for clinicians, yet its endodontic treatment may require a careful instrumentation strategy due to the difficulty in disinfecting the canals in the thin root area without compromising the root structure.

  12. Developmental spinal canal stenosis and somatotype.

    Science.gov (United States)

    Nightingale, S

    1989-01-01

    The hypothesis that somatotype and cervical spine developmental canal stenosis may be associated has been investigated by anthropometry and measurement of lateral projection cervical spine radiographs. A significant association of canal size with somatotype has been found such that those with developmentally narrow canals are more likely to have relatively shorter long-bones, particularly in the upper arm, and longer trunks. Images PMID:2769282

  13. 33 CFR 207.441 - St. Marys Falls Canal and Locks, Mich.; security.

    Science.gov (United States)

    2010-07-01

    ..., gasoline, crude oil or other flammable liquids in bulk, including vessels that are not certified gas free...) Restrictions on transit of vessels. The following classes of vessels will not be permitted to transit the U.S... material. Cleaning and gas freeing of tanks on all hazardous material cargo vessels (as defined in 49 CFR...

  14. 33 CFR 207.440 - St. Marys Falls Canal and Locks, Mich.; use, administration, and navigation.

    Science.gov (United States)

    2010-07-01

    ...) Vessels with non-friction winches or lack of both bow and stern thrusters. Four vessel-supplied line... bow/stern thrusters. Bow and/or stern thruster use shall be kept to a minimum while transiting the Soo... with bow or stern thrusters, may cause control difficulties for certain classes of vessels. Therefore...

  15. Water Quality And Sediment Evaluation for Inner Harbor Navigation Canal Lock Replacement Project, New Orleans, Louisiana

    Science.gov (United States)

    2011-08-01

    Leptocheirus plumulosus 10-day solid phase toxicity tests. .............................................. 127 Table 44. Corbicula fluminea 28-day freshwater...solid phase bioaccumulation tests. ................... 131 Table 45. Corbicula fluminea 28-day freshwater solid phase bioaccumulation tests...132 Table 46. Corbicula fluminea 28-day freshwater solid phase bioaccumulation potential evaluation

  16. Single-ion quantum lock-in amplifier.

    Science.gov (United States)

    Kotler, Shlomi; Akerman, Nitzan; Glickman, Yinnon; Keselman, Anna; Ozeri, Roee

    2011-05-05

    Quantum metrology uses tools from quantum information science to improve measurement signal-to-noise ratios. The challenge is to increase sensitivity while reducing susceptibility to noise, tasks that are often in conflict. Lock-in measurement is a detection scheme designed to overcome this difficulty by spectrally separating signal from noise. Here we report on the implementation of a quantum analogue to the classical lock-in amplifier. All the lock-in operations--modulation, detection and mixing--are performed through the application of non-commuting quantum operators to the electronic spin state of a single, trapped Sr(+) ion. We significantly increase its sensitivity to external fields while extending phase coherence by three orders of magnitude, to more than one second. Using this technique, we measure frequency shifts with a sensitivity of 0.42 Hz Hz(-1/2) (corresponding to a magnetic field measurement sensitivity of 15 pT Hz(-1/2)), obtaining an uncertainty of less than 10 mHz (350 fT) after 3,720 seconds of averaging. These sensitivities are limited by quantum projection noise and improve on other single-spin probe technologies by two orders of magnitude. Our reported sensitivity is sufficient for the measurement of parity non-conservation, as well as the detection of the magnetic field of a single electronic spin one micrometre from an ion detector with nanometre resolution. As a first application, we perform light shift spectroscopy of a narrow optical quadrupole transition. Finally, we emphasize that the quantum lock-in technique is generic and can potentially enhance the sensitivity of any quantum sensor. ©2011 Macmillan Publishers Limited. All rights reserved

  17. Development of the anterior chordal canal.

    Science.gov (United States)

    Tóth, Miklós; Moser, Gerhard; Patonay, Lajos; Oláh, Imre

    2006-01-01

    Resent advances have led to the reexamination of the intraosseous pathway of the chorda tympani a few years ago and they stated that the nerve never enters the mandibular fossa and its exit the skull base in the sphenopetrosal fissure. In our report, 58 temporal bones were investigated after maceration and formalin fixation in order to understand the development of the anterior chordal canal. Our study revealed that the chorda tympani leaves the tympanic cavity through the tympanosquamosal fissure before formation of the anterior chordal canal of Huguier. This canal is situated parallel to and in front of the musculotubal canal and formed by the processus inferior tegminis tympani and the sphenoid bone between the second and fifth years of age. Prior to the age of 2, only the exit of the bony canal exists which is gradually followed by the appearance of a groove in the growing processus inferior tegminis tympani. The borders of the groove elevate and develop to upper and lower plates which lengthen with similar plates of the sphenoid bone, completing the anterior chordal canal by the fifth postnatal year. The entrance of the canal develops above the petrotympanic fissure and similar to the canal itself, it is also completely formed in the fifth year. In case of an incomplete development the anterior chordal canal remains partially opened laterally which might allow the head of the mandibula to effect the chorda tympani mechanically causing Costen's syndrome.

  18. Mode-locking dynamics of a two-color cross-mode-locked femtosecond Ti:sapphire laser

    Energy Technology Data Exchange (ETDEWEB)

    Dykaar, D.R.; Lopez, A.S.; Darack, S.B. [AT and T Bell Labs., Murray Hill, NJ (United States); Knox, W.H. [AT and T Bell Labs., Holmdel, NJ (United States)

    1994-12-31

    The authors demonstrate mode-locked two-wavelength synchronized operation of a single, cw pumped Ti:Sapphire laser. There is no active feedback or external cavity. The measured cross correlation is 105 fs. Wavelengths as much as 57 nm apart can be simultaneously cross-mode-locked. They then investigate the nonlinear interactions between the pulses. They show the nonlinear interaction caused by self focusing scan correct for a difference in cavity lengths of up to {+-}3{micro}m corresponding to 20% of the pulse width on each round trip. Further, they show that the concept of mean group delay can be extended to a pair of pulses with disparate spectra and spatial distribution in a nonlinear regenerative system.

  19. Root canal treatment of mandibular second premolar with four root canals

    Directory of Open Access Journals (Sweden)

    Bander Al-Abdulwahhab

    2015-01-01

    Full Text Available Variation in the morphology of the root canal system of mandibular premolars has been demonstrated. This diverse morphology challenges for the clinician to clean, shape, and fill the entire root canal system. A case report of a mandibular second premolar with four root canals separated at the apical third and underwent endodontic treatment is presented.

  20. MANAGEMENT OF LUMBAR SPINAL CANAL STENOSIS

    Directory of Open Access Journals (Sweden)

    Mukhergee G. S

    2016-06-01

    degenerative. This process is most commonly localised to the facet joints and ligamentum flavum, with the resultant arthritic changes in the joints visible on radiographic studies. Frequently, these abnormalities are symmetrical and bilateral. The L4-L5 level is the most commonly involved, followed by L5-S1 and L3-L4 disc herniation and spondylolisthesis may exacerbate the narrowing further. 1. METHODS This study was taken up to evaluate the management of lumbar spinal canal stenosis cases. The study was conducted from May 2012 to October 2014: A total of 86 patients of 55-70 age groups with degenerative LCS were followed prospectively from May 2012 to October 2014. All the treatment methods were explained to patients and treatment method was determined by patient’s choice. The sample is divided into two groups 42 surgical and 44 conservative based on patient’s preference. MEASUREMENT OF OUTCOME Outcomes were measures of bodily pain and physical function on the medical outcomes study 36-item short-Form General Health Study (SF-36 22-25 and on the modified Oswestry Disability Index 26 measured at 6 weeks, 3 months, 6 months, and 1 year and 18 months. SF-36 scores range from 0 to 100 with higher scores indicating less severe symptoms. The Oswestry Disability Index ranges from 0 to 100, with lower scores indicating less severe symptoms. STUDY INTERVENTION The protocol surgery was standard posterior decompressive laminectomy operated by three surgeons. The type of nonsurgical care included physical therapy (68% of patients, epidural injections (56%, the use of anti-inflammatory drugs (55% and use of opioid analgesics (27%. Informed consent was taken from every patient after explaining the particulars of study interventions. In this study, 82% patients (n=70 were in age group 50-59 years with an average age of 50.2 years with a total sample size of 86 patients followed by 60-69 years age group. Both the surgical and conservative groups had similar sex distribution. Initially

  1. 5 CFR 315.601 - Appointment of former employees of the Canal Zone Merit System or Panama Canal Employment System.

    Science.gov (United States)

    2010-01-01

    ... Canal Zone Merit System or Panama Canal Employment System. 315.601 Section 315.601 Administrative... employees of the Canal Zone Merit System or Panama Canal Employment System. (a) Agency authority. This... Zone Merit System, which was in effect before March 31, 1982, or under the Panama Canal Employment...

  2. Unusual Cause of Knee Locking

    Directory of Open Access Journals (Sweden)

    Gazi Huri

    2013-01-01

    Full Text Available We report a case of partial intrasubstance tear of popliteus tendon as an unusual cause of pseudolocking of the knee. A 13-year-old semiprofessional soccer player applied to our clinic with a locked right knee in spite of the therapy applied (cold pack, NSAID, and immobilization in another institution 20 days after the injury. Significant extension loss was observed in his right knee with 30∘–90∘ ROM. Magnetic resonance imaging (MRI and arthroscopy confirmed the intrasubstance tear of popliteus tendon and synovitis. The ruptured part of the tendon was debrided, and the inflammatory tissue around the tendon, which may lead to pseudolocking, was gently removed with a shaver in order to regain the normal ROM. The patient was discharged with full ROM and weight bearing first day after the surgery. To our knowledge, this is the first case demonstrating intrasubstance tear of popliteus tendon causing pseudolocking of the knee.

  3. Fiber Transmission Stabilization by Optical Heterodyning Techniques and Synchronization of Mode-Locked Lasers Using Two Spectral Lines

    CERN Document Server

    Staples, J W

    2005-01-01

    Stabilization of the transit time through a glass fiber using an optical heterodyne technique promises to provide jitter reduction down to the few femtosecond level using inexpensive commodity hardware. An acousto-optical frequency shifter provides the optical frequency offset that is used to downconvert phase shifts at optical frequency to equivalent phase shifts at radio frequency which are used to close a phase-lock loop driving a piezoelectric phase shifter. Using the stabilized fiber transmission medium, two spectral lines of a mode locked laser lock two low-power CW lasers which are transmitted to a receiver which phase locks the same spectral lines of a second mode-locked laser to the first. The optical transmission system operates at low power and is linear, providing excellent signal-to-noise ratio and allows many signals to be transmitted without mutual interference. Experimental results will be presented.

  4. No Snowball on Habitable Tidally Locked Planets

    Science.gov (United States)

    Checlair, Jade; Menou, Kristen; Abbot, Dorian S.

    2017-08-01

    The TRAPPIST-1, Proxima Centauri, and LHS 1140 systems are the most exciting prospects for future follow-up observations of potentially inhabited planets. All of the planets orbit nearby M-stars and are likely tidally locked in 1:1 spin-orbit states, which motivates the consideration of the effects that tidal locking might have on planetary habitability. On Earth, periods of global glaciation (snowballs) may have been essential for habitability and remote signs of life (biosignatures) because they are correlated with increases in the complexity of life and in the atmospheric oxygen concentration. In this paper, we investigate the snowball bifurcation (sudden onset of global glaciation) on tidally locked planets using both an energy balance model and an intermediate-complexity global climate model. We show that tidally locked planets are unlikely to exhibit a snowball bifurcation as a direct result of the spatial pattern of insolation they receive. Instead, they will smoothly transition from partial to complete ice coverage and back. A major implication of this work is that tidally locked planets with an active carbon cycle should not be found in a snowball state. Moreover, this work implies that tidally locked planets near the outer edge of the habitable zone with low CO2 outgassing fluxes will equilibrate with a small unglaciated substellar region rather than cycling between warm and snowball states. More work is needed to determine how the lack of a snowball bifurcation might affect the development of life on a tidally locked planet.

  5. In vitro comparison of passive and continuous ultrasonic irrigation in simulated lateral canals of extracted teeth.

    Science.gov (United States)

    Castelo-Baz, Pablo; Martín-Biedma, Benjamín; Cantatore, Giuseppe; Ruíz-Piñón, Manuel; Bahillo, José; Rivas-Mundiña, Berta; Varela-Patiño, Purificación

    2012-05-01

    Complete endodontic system disinfection requires the removal of vital and necrotic pulp tissue, microorganisms, and toxins. The purpose of this study was to compare the effects of 2 ultrasonic irrigation techniques on the penetration of sodium hypochlorite into the main canal and simulated lateral canals of extracted teeth. Two simulated lateral canals each were created 2, 4, and 6 mm from the working length in 60 single-rooted teeth (6 canals/tooth, n = 360). To resemble the clinical situation, a closed system was created in each tooth. The teeth were randomly assigned to 3 experimental irrigation groups: group 1 (n = 20), positive pressure irrigation (PPI); group 2 (n = 20), passive ultrasonic irrigation (PUI); and group 3 (n = 20), continuous ultrasonic irrigation (CUI). Samples were evaluated by direct observation of still images recorded under a dental operating microscope. To examine irrigating solution penetration, 20% Chinese ink (Sanford Rotring GmbH, Hamburg, Germany) was added to a 5% sodium hypochlorite solution and delivered into the root canals. The results showed a significantly higher (P < .05) penetration of irrigant into the lateral canals in the CUI group. PUI and CUI did not differ significantly in solution penetration into the apical thirds of the main canals. The PPI group showed a significantly lower penetration of sodium hypochlorite into the main and lateral canals compared with the CUI and PUI groups. CUI as a final rinse significantly increased the penetration of irrigating solution into simulated lateral canals. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  6. Tibial plateau levelling osteotomy locking-compression plates for stabilisation of canine and feline ilial body fractures.

    Science.gov (United States)

    Guthrie, J W; Kalff, S

    2017-12-12

    To evaluate the clinical and radiographic outcomes following surgical stabilisation of ilial fractures in dogs and cats using a laterally applied Synthes TPLO locking compression plate. Medical records and radiographs of seven dogs and two cats which had undergone surgical repair of an ilial body fracture with a TPLO locking compression plate were reviewed. Long-term clinical follow-up was obtained from an owner or referring veterinarian questionnaire. Fracture reduction was anatomic in six of nine ilia and near-anatomic in three of nine. All but one fracture achieved osseous union by 6 weeks after surgery. No screw loosening or implant-related complications occurred in any patient. There was pelvic canal narrowing in six of nine patients (median reduction in pelvic canal diameter was 4·9%). No intraoperative or postoperative complications were reported. Lateral plating of canine and feline ilial fractures with a Synthes TPLO locking compression plate was associated with a low complication rate and satisfactory radiographic and clinical outcomes in this small case series. © 2017 British Small Animal Veterinary Association.

  7. Optimal database locks for efficient integrity checking

    DEFF Research Database (Denmark)

    Martinenghi, Davide

    2004-01-01

    In concurrent database systems, correctness of update transactions refers to the equivalent effects of the execution schedule and some serial schedule over the same set of transactions. Integrity constraints add further semantic requirements to the correctness of the database states reached upon...... the execution of update transactions. Several methods for efficient integrity checking and enforcing exist. We show in this paper how to apply one such method to automatically extend update transactions with locks and simplified consistency tests on the locked entities. All schedules produced in this way...... are conflict serializable and preserve consistency. For certain classes of databases we also guarantee that the amount of locked database entities is minimal....

  8. HIGH RISK IN ROOT CANAL NEGOCIATION IN ELDERLY PATIENTS: CLINICAL CASE SERIES

    Directory of Open Access Journals (Sweden)

    Paula PERLEA

    2015-03-01

    Full Text Available Several clinical cases outline the difficulties of root canal treatment, due to the morphological changes of the endodontic space in elderly patients. The changes in the shape of pulp chamber and root canal make the treatment more difficult. It is also shown that the pulp chamber diminishes, due to reparative dentin. Calcification of the pulp space makes more difficult the access to the cavity. The obliterated canals lead to a challenging negotiation of the root canals. To avoid errors in the appreciation of the general health condition of the patient, the specialists should have an accurate preoperative radiograph or cone beam computing tomography (CBCT, use magnification (dental operative microscope, safe-ended burs, consider carefully any morphological changes, and apply the most proper techniques.

  9. UNUSUAL CASE OF A MAXILLARY FIRST INCISOR WITH TWO ROOT CANALS.

    Directory of Open Access Journals (Sweden)

    Janet Kirilova

    2014-07-01

    Full Text Available Introduction: Maxillary central incisors usually have one root with one root canal. The cases with two root canals are extremely rare. Purpose: The aim was to present an unusual case of a maxillary first incisor with two root canals and the methods of treatment. Material and methods: The 48-year old patient had a painful swelling above the first maxillary incisor. The diagnosis was Periodontitis chronica granulomatosa diffusa exacerbata. After exploration of the pulp chamber, the inspection with an operating microscope was found two root canals. The lesion was covered to periapical and the part of marginal periodontium. The decision was taken of combined endodontic and surgery treatment. Results and discussion: After 7-year follow-up, there was a healing of the lesions and no recurrence. Conclusions: The combined endodontic and surgery treatment was successful choice for preservation of the tooth.

  10. Scalable Multicore Motion Planning Using Lock-Free Concurrency.

    Science.gov (United States)

    Ichnowski, Jeffrey; Alterovitz, Ron

    2014-10-01

    We present PRRT (Parallel RRT) and PRRT* (Parallel RRT*), sampling-based methods for feasible and optimal motion planning designed for modern multicore CPUs. We parallelize RRT and RRT* such that all threads concurrently build a single motion planning tree. Parallelization in this manner requires that data structures, such as the nearest neighbor search tree and the motion planning tree, are safely shared across multiple threads. Rather than rely on traditional locks which can result in slowdowns due to lock contention, we introduce algorithms based on lock-free concurrency using atomic operations. We further improve scalability by using partition-based sampling (which shrinks each core's working data set to improve cache efficiency) and parallel work-saving (in reducing the number of rewiring steps performed in PRRT*). Because PRRT and PRRT* are CPU-based, they can be directly integrated with existing libraries. We demonstrate that PRRT and PRRT* scale well as core counts increase, in some cases exhibiting superlinear speedup, for scenarios such as the Alpha Puzzle and Cubicles scenarios and the Aldebaran Nao robot performing a 2-handed task.

  11. Stifle arthrodesis using a locking plate system in six dogs.

    Science.gov (United States)

    Petazzoni, M; Nicetto, T

    2015-01-01

    To describe the use of the Fixin locking plate system for stifle arthrodesis in dogs and to retrospectively report the clinical and radiographic outcomes in six cases. Medical records of dogs that had arthrodesis with the Fixin locking plate system were reviewed. For each patient, data pertaining to signalment and implant used were recorded. Plate series and thickness, number of screws placed, number of cortices engaged, and screw diameters were also recorded. The outcome was determined from clinical and radiographic follow-ups. Radiographic outcomes assessed included the measurement of the postoperative femoral-tibial angle in the sagittal plane. Six dogs met the inclusion criteria for the study. Mean body weight was 13 kg (range: 3 - 34 kg). Radiographic follow-up (mean: 32 weeks, range: 3 - 52 weeks) was available for all dogs. In one case, an intra-operative complication occurred. In another case, a tibial fracture occurred 20 days after surgery. All arthrodeses healed and no implant complication was detected although all cases had mechanical lameness. Stifle arthrodesis can be performed successfully using a Fixin locking plate system.

  12. [Upper lateral incisor with 2 canals].

    Science.gov (United States)

    Fabra Campos, H

    1991-01-01

    Clinical case summary of the patient with an upper lateral incisor with two root canals. The suspicion that there might be an anatomic anomaly in the root that includes a complex root canal system was made when an advanced radicular groove was detected in the lingual surface or an excessively enlarged cingulum.

  13. The enigma of the lateral canal.

    Science.gov (United States)

    Weine, F S

    1984-10-01

    It is difficult to summarize an article of this type, in which the author is certain that his case has been presented fairly, but is aware that other views that are contrary could be stated and endorsed by pertinent clinical cases. Bearing this fact in mind, I wish to reiterate the following: Lateral canals are demonstrated in endodontic cases with much less frequency than they exist. This variance rarely, if ever, causes an endodontic failure. Some demonstrated lateral canals may really be other conditions. Preoperative evaluation should include examination of radiographs for lateral, as well as periapical, lesions. Lateral canals may be demonstrated by a variety of filling techniques. Careful canal preparation may enhance the frequency of such demonstration. Cases with necrotic pulps probably yield more frequent demonstration than do cases with vital pulps. Lateral canals harboring inflamed and/or infected material may cause pain during endodontic treatment. They may simulate periodontal disease and may cause problems with treatment if present when a tooth is left open for drainage. Periodontal disease may cause pulp exposure via lateral canals located coronally. Improper use of post room may lead to lateral failure from breakdown of tissue in a lateral canal. The enigma of the lateral canal has been the object of description and discussion in many articles, but no one is truly certain of their exact significance in endodontic therapy for the long haul.

  14. Computed Tomography Findings of Mandibular Nutrient Canals.

    Science.gov (United States)

    Kawashima, Yusuke; Sekiya, Kotaro; Sasaki, Yusuke; Tsukioka, Tsuneyuki; Muramatsu, Teruaki; Kaneda, Takashi

    2015-08-01

    The purpose of this study was to assess computed tomography (CT) findings of mandibular nutrient canals using CT images. We retrospectively analyzed the mandibular CT images of 194 consecutive patients. For image analysis such as canal prevalence, location, number, size, shape, and the CT value of nutrient foramina were determined using CT axial images of 0.5 and 3 mm slice thickness. We revealed that the nutrient canals were seen 94.3% in the mandible, mostly seen in the anterior region. By location, nutrient canals were particularly seen between the central and lateral incisors. The mean number of nutrient canals was 2.7. The mean diameter of the nutrient foramen between the central and lateral incisors was 1.0 mm. In about 80% of the cases, foramina between the central and lateral incisors were ovoid. The mean CT value for the nutrient foramina between the central and lateral incisors was 411 HU. Mandibular nutrient canals were ovoid shape, and the mean CT value was 411 HU. By preoperative knowledge of the position and anatomy of the mandibular nutrient canals, complications such as injury to the nutrient canals can be avoided.

  15. 27 CFR 19.282 - Breaking Government locks.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Breaking Government locks... Breaking Government locks. Where affixed, Government locks shall not be removed without the authorization... obtain authorization from an appropriate TTB officer, Government locks may be removed, by the proprietor...

  16. Type III apical transportation of root canal

    Directory of Open Access Journals (Sweden)

    Shiv P Mantri

    2012-01-01

    Full Text Available Procedural accidents leading to complications such as canal transportation have been ascribed to inapt cleaning and shaping concepts. Canal transportation is an undesirable deviation from the natural canal path. Herewith a case of apical transportation of root canal resulting in endodontic retreatment failure and its management is presented. A healthy 21-year-old young male presented discomfort and swelling associated with painful endodontically retreated maxillary incisor. Radiograph revealed periradicular radiolucency involving underfilled 11 and overfilled 12. Insufficiently obturated 11 exhibited apical transportation of canal. This type III transportation was treated by periradicular surgery and repair using white mineral trioxide aggregate (MTA. Comfortable asymptomatic patient presented uneventful healing at third and fourth month recall visits. A decrease in the size of radiolucency in radiograph supported the clinical finding. In the present case, MTA is useful in repairing the transportation defect. The result of these procedures is predictable and successful.

  17. Updated regime equations for alluvial Egyptian canals

    Directory of Open Access Journals (Sweden)

    Fahmy Salah Abdelhaleem

    2016-03-01

    Full Text Available Real accuracy of several regime relationships for designing stable alluvial channels in Egypt was determined. Extensive field measurements had been carried out on 26 Egyptian stable canals, which cover various categories of irrigation canals starting from distributary, branch to carrier canals in Egypt. Analysis of 1484 velocity profiles for 371 cross sections was employed in order to formulate new regime equations characterizing Egyptian canals. The functional formulations to include the flow depth, cross section area, hydraulic radius and mean velocity were achieved. This research compared the deduced formulas from the measured data with the equations derived by other researchers for stable channel design. It was found that the derived formulas are reliable and could help in the design of Egyptian canals to convey a discharge ranging from 0.11 to 287.5 m3/s (0.0095–24.84 millions m3/day.

  18. Quantum Enigma Machines and the Locking Capacity of a Quantum Channel

    Directory of Open Access Journals (Sweden)

    Saikat Guha

    2014-01-01

    Full Text Available The locking effect is a phenomenon that is unique to quantum information theory and represents one of the strongest separations between the classical and quantum theories of information. The Fawzi-Hayden-Sen locking protocol harnesses this effect in a cryptographic context, whereby one party can encode n bits into n qubits while using only a constant-size secret key. The encoded message is then secure against any measurement that an eavesdropper could perform in an attempt to recover the message, but the protocol does not necessarily meet the composability requirements needed in quantum key distribution applications. In any case, the locking effect represents an extreme violation of Shannon’s classical theorem, which states that information-theoretic security holds in the classical case if and only if the secret key is the same size as the message. Given this intriguing phenomenon, it is of practical interest to study the effect in the presence of noise, which can occur in the systems of both the legitimate receiver and the eavesdropper. This paper formally defines the locking capacity of a quantum channel as the maximum amount of locked information that can be reliably transmitted to a legitimate receiver by exploiting many independent uses of a quantum channel and an amount of secret key sublinear in the number of channel uses. We provide general operational bounds on the locking capacity in terms of other well-known capacities from quantum Shannon theory. We also study the important case of bosonic channels, finding limitations on these channels’ locking capacity when coherent-state encodings are employed and particular locking protocols for these channels that might be physically implementable.

  19. Broadly tunable mode-locked Ho:YAG ceramic laser around 2.1 µm.

    Science.gov (United States)

    Wang, Yicheng; Lan, Ruijun; Mateos, Xavier; Li, Jiang; Hu, Chen; Li, Chaoyu; Suomalainen, Soile; Härkönen, Antti; Guina, Mircea; Petrov, Valentin; Griebner, Uwe

    2016-08-08

    A passively mode-locked Ho:YAG ceramic laser around 2.1 µm is demonstrated using GaSb-based near-surface SESAM as saturable absorber. Stable and self-starting mode-locked operation is realized in the entire tuning range from 2059 to 2121 nm. The oscillator operated at 82 MHz with a maximum output power of 230 mW at 2121 nm. The shortest pulses with duration of 2.1 ps were achieved at 2064 nm. We also present spectroscopic properties of Ho:YAG ceramics at room temperature.

  20. Comparing the Overhead of Lock-based and Lock-free Implementations of Priority Queues

    DEFF Research Database (Denmark)

    Passas, Stavros; Karlsson, Sven

    2011-01-01

    With the advent of multi-core processors, concurrent data structures have received a renewed interest. While concurrent data structures where previously used mainly in high-performance computing, now they are found in all types of computer systems. A major challenge when designing such data...... instructions as the lock-based implementation. However, the lock-free implementation outperforms the lock-based when multiple cores are used and the data structure is contended....

  1. Picosecond passively mode-locked mid-infrared fiber laser

    Science.gov (United States)

    Wei, C.; Zhu, X.; Norwood, R. A.; Kieu, K.; Peyghambarian, N.

    2013-02-01

    Mode-locked mid-infrared (mid-IR) fiber lasers are of increasing interest due to their many potential applications in spectroscopic sensors, infrared countermeasures, laser surgery, and high-efficiency pump sources for nonlinear wavelength convertors. Er3+-doped ZBLAN (ZrF4-BaF2-LaF3-AlF3-NaF) fiber lasers, which can emit mid-IR light at 2.65-2.9 μm through the transition from the upper energy level 4I11/2 to the lower laser level 4I13/2, have attracted much attention because of their broad emission range, high optical efficiency, and the ready availability of diode pump lasers at the two absorption peaks of Er3+ ions (975 nm and 976 nm). In recent years, significant progress on high power Er3+- doped ZBLAN fiber lasers has been achieved and over 20 watt cw output at 2.8 μm has been demonstrated; however, there has been little progress on ultrafast mid-IR ZBLAN fiber lasers to date. We report a passively mode-locked Er3+- doped ZBLAN fiber laser in which a Fe2+:ZnSe crystal was used as the intracavity saturable absorber. Fe2+:ZnSe is an ideal material for mid-IR laser pulse generation because of its large saturable absorption cross-section and small saturation energy along with the excellent opto-mechanical (damage threshold ~2 J/cm2) and physical characteristics of the crystalline ZnSe host. A 1.6 m double-clad 8 mol% Er3+-doped ZBLAN fiber was used in our experiment. The fiber core has a diameter of 15 μm and a numerical aperture (NA) of 0.1. The inner circular cladding has a diameter of 125 μm and an NA of 0.5. Both continuous-wave and Q-switched mode-locking pulses at 2.8 μm were obtained. Continuous-wave mode locking operation with a pulse duration of 19 ps and an average power of 51 mW were achieved when a collimated beam traversed the Fe2+:ZnSe crystal. When the cavity was modified to provide a focused beam at the Fe2+:ZnSe crystal, Q-switched mode-locked operation with a pulse duration of 60 ps and an average power of 4.6 mW was achieved. More powerful

  2. Suture locking of isolated internal locking knotless suture anchors is not affected by bone quality

    Directory of Open Access Journals (Sweden)

    Woodmass JM

    2015-06-01

    Full Text Available Jarret M Woodmass,1 Graeme Matthewson,1 Yohei Ono,1,2 Aaron J Bois,1 Richard S Boorman,1 Ian KY Lo,1 Gail M Thornton1,31Department of Surgery, Section of Orthopaedic Surgery, McCaig Institute for Bone and Joint Health, University of Calgary, Calgary, AB, Canada; 2Department of Orthopaedic Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan; 3Department of Orthopaedics, University of British Columbia, Vancouver, BC, Canada Purpose: The purpose of this study was to evaluate the mechanical performance of different suture locking mechanisms including: i interference fit between the anchor and the bone (eg, 4.5 mm PushLock, 5.5 mm SwiveLock, ii internal locking mechanism within the anchor itself (eg, 5.5 mm SpeedScrew, or iii a combination of interference fit and internal locking (eg, 4.5 mm MultiFIX P, 5.5 mm MultiFIX S. Methods: Anchors were tested in foam blocks representing normal (20/8 foam or osteopenic (8/8 foam bone, using standard suture loops pulled in-line with the anchor to isolate suture locking. Mechanical testing included cyclic testing for 500 cycles from 10 N to 60 N at 60 mm/min, followed by failure testing at 60 mm/min. Displacement after 500 cycles at 60 N, number of cycles at 3 mm displacement, load at 3 mm displacement, and maximum load were evaluated. Results: Comparing 8/8 foam to 20/8 foam, load at 3 mm displacement and maximum load were significantly decreased (P<0.05 with decreased bone quality for anchors that, even in part, relied on an interference fit suture locking mechanism (ie, 4.5 mm PushLock, 5.5 mm SwiveLock, 4.5 mm MultiFIX P, 5.5 mm MultiFIX S. Bone quality did not affect the mechanical performance of 5.5 mm SpeedScrew anchors which have an isolated internal locking mechanism. Conclusion: The mechanical performance of anchors that relied, even in part, on interference fit were affected by bone quality. Isolated internal locking knotless suture anchors functioned independently of bone quality

  3. La filosofia del lenguaje de Locke

    National Research Council Canada - National Science Library

    Arango, Alejandro Patino

    2006-01-01

    ... en la Filosofia Analitica del siglo XX. Esta influencia se presenta a traves del analisis que realiza Locke sobre el papel que cumple el lenguaje en el problema del conocimiento, lo cual lo conduce a criticar la metafisica, concebir...

  4. QPSK regeneration without active phase-locking

    DEFF Research Database (Denmark)

    Kjøller, Niels-Kristian; Da Ros, Francesco; Røge, Kasper Meldgaard

    2016-01-01

    QPSK regeneration without active phase stabilization is investigated in numerical simulations. We propose an improved scheme for phase-locking free QPSK regeneration showing significant improvements in the error vector magnitude of the signal....

  5. Universal Spin-Momentum Locked Optical Forces

    CERN Document Server

    Kalhor, Farid; Jacob, Zubin

    2015-01-01

    Evanescent electromagnetic waves possess spin-momentum locking, where the direction of propagation (momentum) is locked to the inherent polarization of the wave (transverse spin). We study the optical forces arising from this universal phenomenon and show that the fundamental origin of recently reported non-trivial optical chiral forces is spin-momentum locking. For evanescent waves, we show that the direction of energy flow, direction of decay, and direction of spin follow a right hand rule for three different cases of total internal reflection, surface plasmon polaritons, and $HE_{11}$ mode of an optical fiber. Furthermore, we explain how the recently reported phenomena of lateral optical force on chiral and achiral particles is caused by the transverse spin of the evanescent field and the spin-momentum locking phenomenon. Finally, we propose an experiment to identify the unique lateral forces arising from the transverse spin in the optical fiber and point to fundamental differences of the spin density from...

  6. Mode-locked silicon evanescent lasers

    National Research Council Canada - National Science Library

    Brian R. Koch; Alexander W. Fang; Oded Cohen; John E. Bowers

    2007-01-01

    .... The mode locked lasers generate 4 ps pulses with low jitter and extinction ratios above 18 dB, making them suitable for data and telecommunication transmitters and for clock generation and distribution...

  7. Assessing the present state and potential of Medicaid controlled substance lock-in programs.

    Science.gov (United States)

    Roberts, Andrew W; Skinner, Asheley Cockrell

    2014-05-01

    Nonmedical use of prescription medications--particularly controlled substances--has risen dramatically in recent decades, resulting in alarming increases in overdose-related health care utilization, costs, and mortality. The Centers for Disease Control and Prevention estimate that 80% of abused and misused controlled substances originate as legal prescriptions. As such, policymakers and payers have the opportunity to combat nonmedical use by regulating controlled substance accessibility within legal prescribing and dispensing processes. One common policy strategy is found in Medicaid controlled substance lock-in programs. Lock-in programs identify Medicaid beneficiaries exhibiting high-risk controlled substance seeking behavior and "lock in" these patients to, typically, a single prescriber and pharmacy from which they may obtain Medicaid-covered controlled substance prescriptions. Lock-in restrictions are intended to improve care coordination between providers, reduce nonmedical use behaviors, and limit Medicaid costs stemming from nonmedical use and diversion. Peer-reviewed and gray literature have been examined to assess the current prevalence and design of Medicaid lock-in programs, as well as the current evidence base for informing appropriate program design and understanding program effectiveness. Forty-six state Medicaid agencies currently operate lock-in programs. Program design varies widely between states in terms of defining high-risk controlled substance use, the scope of actual lock-in restrictions, and length of program enrollment. Additionally, there is a remarkable dearth of peer-reviewed literature evaluating the design and effectiveness of Medicaid lock-in programs. Nearly all outcomes evidence stemmed from publicly accessible internal Medicaid program evaluations, which largely investigated cost savings to the state. Lock-in programs are highly prevalent and poised to play a meaningful role in curbing the prescription drug abuse epidemic. However

  8. Coexistence of noise-like pulse and high repetition rate harmonic mode-locking in a dual-wavelength mode-locked Tm-doped fiber laser.

    Science.gov (United States)

    Wang, Yazhou; Li, Jianfeng; Zhang, Entao; Mo, Kundong; Wang, Yanyan; Liu, Fei; Zhou, Xiaojun; Liu, Yong

    2017-07-24

    Coexistence of harmonic mode-locking (HML) and noise-like pulse (NLP) were experimentally observed in a dual-wavelength mode-locked Tm-doped fiber laser for the first time. The coexistence patterns were self-started and maintained within a wide pump range by appropriately setting the intra-cavity polarization state. The HML was obtained at 1955.3 nm with a varied repetition rate range from 324 MHz to 1.138 GHz which benefits from the dispersion compensation, while the NLP observing at 1983.2 nm can operate at either fundamental repetition rate of 4.765 MHz or second harmonic state. Experimental investigations show that the coexistence patterns are caused by the wavelength-dependent phase delay of the mode-locked fiber cavity. Moreover, dual-wavelength NLP was also observed for the first time at 2 μm spectral region by changing the intra-cavity polarization state.

  9. Transverse mode-locking in microcavity lasers

    Science.gov (United States)

    Gordon, R.; Heberle, A. P.; Cleaver, J. R. A.

    2002-12-01

    We experimentally demonstrate mode-locking between the transverse modes of a laser. A vertical-cavity surface-emitting laser with evenly-spaced transverse modes is shown to emit a train of 2.1±0.1 ps pulses with an 11 ps repetition rate and a timing jitter of 235±30 fs. Transverse mode-locking in microcavity lasers has potential to improve the compactness, stability, integrability, repetition rate tunability, and efficiency of ultrafast optical communication sources.

  10. Endodontic Treatment of a Maxillary First Molar with Seven Root Canals Confirmed with Cone Beam Computer Tomography – Case Report

    Science.gov (United States)

    2014-01-01

    The most common configuration of the maxillary first molar is the presence of three roots and four root canals, although the presence of several other configurations have already been reported. The objective of this work is to present a rare anatomic configuration with seven root canals diagnosed during an endodontic therapy. Endodontic treatment was performed using a dental operating microscope. Exploring the grooves surrounding the main canals with ultrasonic troughing was able expose unexpected root canals. Instrumentation with files of smaller sizes and tapers was performed to prevent root physical weakness. The anatomic configuration was confirmed with a Cone Beam Computer Tomography image analysis which was able to clearly show the presence of seven root canals. An electronic database search was conducted to identify all the published similar cases and the best techniques to approach them are discussed. PMID:25121069

  11. Exploiting the potential of free software to evaluate root canal biomechanical preparation outcomes through micro-CT images.

    Science.gov (United States)

    Neves, A A; Silva, E J; Roter, J M; Belladona, F G; Alves, H D; Lopes, R T; Paciornik, S; De-Deus, G A

    2015-11-01

    To propose an automated image processing routine based on free software to quantify root canal preparation outcomes in pairs of sound and instrumented roots after micro-CT scanning procedures. Seven mesial roots of human mandibular molars with different canal configuration systems were studied: (i) Vertucci's type 1, (ii) Vertucci's type 2, (iii) two individual canals, (iv) Vertucci's type 6, canals (v) with and (vi) without debris, and (vii) canal with visible pulp calcification. All teeth were instrumented with the BioRaCe system and scanned in a Skyscan 1173 micro-CT before and after canal preparation. After reconstruction, the instrumented stack of images (IS) was registered against the preoperative sound stack of images (SS). Image processing included contrast equalization and noise filtering. Sound canal volumes were obtained by a minimum threshold. For the IS, a fixed conservative threshold was chosen as the best compromise between instrumented canal and dentine whilst avoiding debris, resulting in instrumented canal plus empty spaces. Arithmetic and logical operations between sound and instrumented stacks were used to identify debris. Noninstrumented dentine was calculated using a minimum threshold in the IS and subtracting from the SS and total debris. Removed dentine volume was obtained by subtracting SS from IS. Quantitative data on total debris present in the root canal space after instrumentation, noninstrumented areas and removed dentine volume were obtained for each test case, as well as three-dimensional volume renderings. After standardization of acquisition, reconstruction and image processing micro-CT images, a quantitative approach for calculation of root canal biomechanical outcomes was achieved using free software. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  12. Comparison of tibial plateau angle changes after tibial plateau leveling osteotomy fixation with conventional or locking screw technology.

    Science.gov (United States)

    Conkling, Amanda L; Fagin, Bennett; Daye, R Mark

    2010-06-01

    To compare the effects of locking and conventional screws on postoperative tibial plateau angle (TPA), osteotomy healing, and complication rate after tibial plateau leveling osteotomy (TPLO) in dogs treated for naturally occurring cranial cruciate ligament (CCL) rupture. Prospective clinical study. Dogs (n=118) with CCL rupture. Dogs (> or =20 kg) with unilateral CCL rupture and sufficient bone stock for TPLO and use of a 3.5-mm-broad or -narrow TPLO plate were sequentially allocated to have plate fixation with locking or conventional screws. Data analyzed included breed, age, sex, body weight, body condition score, limb operated, implants used, meniscal status, operative time, and days to recheck. Preoperative, immediate postoperative, and 8-week recheck mediolateral radiographs were reviewed, and TPA, complications, and healing status were evaluated. Stifles in the locking screw group had significantly less change in postoperative TPA than stifles in the conventional screw group. Locking screw fixation also had significantly higher grades of osteotomy healing, assessed on a mediolateral radiographic view. TPLO plates secured with locking screws are acceptable when compared with those secured with conventional screws; osteotomy healing is improved and TPA better conserved when using locking screws. Locking screw fixation serves to increase stabilization of TPA during TPLO healing and provides improved radiographic evidence of osteotomy healing.

  13. Locked intramedullary total wrist arthrodesis.

    Science.gov (United States)

    Orbay, Jorge L; Feliciano, Eric; Orbay, Carolina

    2012-11-01

    Total wrist arthrodesis is commonly performed using fixation plates, which can produce soft tissue irritation, often require removal, and limit the ability to position the hand in space. The Skeletal Dynamics IMPLATE is an intramedullary total wrist fusion device designed to provide stable fixation while avoiding the problems associated with plates. Radial and metacarpal locked intramedullary nails are inserted and joined by a connector. Desired hand placement is achieved by selecting the proper connector length and angle, then orienting it appropriately. Fusion mass compression is obtained by virtue of longitudinal threads on the radial nail that allow for length adjustment. Seven wrists in three men and four women were treated with this device and followed for a minimum of 24 weeks. In all cases, local cancellous bone graft was used and the third carpometacarpal (CMC) joint incorporated into the fusion. The median age was 49 (range, 28-71) years. Indications for fusion were two posttraumatic arthritides, three rheumatoid arthritides, one spastic deformity, and one infection. Patients were evaluated before surgery and at final follow-up using the Fernandez pain score and grip strength measurements using a hand-held dynamometer. All patients improved their grip strength and decreased their pain scores. All fusions united, and none of the patients presented dorsal soft tissue problems or required implant removal. One rheumatoid patient required secondary surgery for removal of a retained palmar osteophyte. This device delivers stable fixation, facilitates hand placement, and does not require removal.

  14. Free fructose is conformationally locked.

    Science.gov (United States)

    Cocinero, Emilio J; Lesarri, Alberto; Écija, Patricia; Cimas, Álvaro; Davis, Benjamin G; Basterretxea, Francisco J; Fernández, José A; Castaño, Fernando

    2013-02-20

    Fructose has been examined under isolation conditions using a combination of UV ultrafast laser vaporization and Fourier-transform microwave (FT-MW) spectroscopy. The rotational spectra for the parent, all (six) monosubstituted (13)C species, and two single D species reveal unambiguously that the free hexoketose is conformationally locked in a single dominant β-pyranose structure. This six-membered-chair skeleton adopts a (2)C(5) configuration (equivalent to (1)C(4) in aldoses). The free-molecule structure sharply contrasts with the furanose form observed in biochemically relevant polysaccharides, like sucrose. The structure of free fructose has been determined experimentally using substitution and effective structures. The enhanced stability of the observed conformation is primarily attributed to a cooperative network of five intramolecular O-H···O hydrogen bonds and stabilization of both endo and exo anomeric effects. Breaking a single intramolecular hydrogen bond destabilizes the free molecule by more than 10 kJ mol(-1). The structural results are compared to ribose, recently examined with rotational resolution, where six different conformations coexist with similar conformational energies. In addition, several DFT and ab initio methods and basis sets are benchmarked with the experimental data.

  15. Looking back at Love Canal

    Energy Technology Data Exchange (ETDEWEB)

    Deegan, J. Jr.

    1987-04-01

    The comprehensive environmental study which describes the results of a monitoring program conducted by EPA at Love Canal is evaluated by EPA's former study director. Attention is focused on the episode's history and the agency's study methods. The aim of the program was to constitute a study team, design a monitoring study, reprogram and reallocate the financial resources needed to conduct the study, and identify and employ contractors who would collect and analyze environmental samples. The agency was directed to ensure the quality of the data acquired from various environmental media and analyzed by numerous laboratories; to integrate, interpret, and report the data; and to assess, from an environmental perspective, the habitability of the area.

  16. Three types of pulses delivered from a nanotube-mode-locked fiber laser

    Science.gov (United States)

    Yao, X. K.

    2015-07-01

    Three types of pulses are experimentally investigated in a switchable normal-dispersion nanotube-mode-locked fiber laser by adjusting polarizer controller and pump power. They are a standard dissipative-soliton (DS), conventional soliton (CS)-like pulse, and noiselike pulse, which correspond to three mode-locking states. The standard DS with a rectangular spectrum possesses a Gaussian-shape pulse. The CS-like operation has a Lorenz shape, and the spectrum involves several sidebands similar to the CS case. For the noiselike pulse with a bell-shaped spectrum, a 317 fs peak rides upon the 132.5 ps pedestal in the autocorrelation trace. The spectra of these three pulse operations are centered at three close wavelengths. The generation of three such different types of pulses in one identical normal- dispersion laser cavity may find an important application for the future of mode-locked laser research.

  17. Analysis of first and second order binary quantized digital phase-locked loops for ideal and white Gaussian noise inputs

    Science.gov (United States)

    Blasche, P. R.

    1980-01-01

    Specific configurations of first and second order all digital phase locked loops are analyzed for both ideal and additive white gaussian noise inputs. In addition, a design for a hardware digital phase locked loop capable of either first or second order operation is presented along with appropriate experimental data obtained from testing of the hardware loop. All parameters chosen for the analysis and the design of the digital phase locked loop are consistent with an application to an Omega navigation receiver although neither the analysis nor the design are limited to this application.

  18. High-Power Hybrid Mode-Locked External Cavity Semiconductor Laser Using Tapered Amplifier with Large Tunability

    Directory of Open Access Journals (Sweden)

    Andreas Schmitt-Sody

    2008-01-01

    Full Text Available We report on hybrid mode-locked laser operation of a tapered semiconductor amplifier in an external ring cavity, generating pulses as short as 0.5 ps at 88.1 MHz with an average power of 60 mW. The mode locking is achieved through a combination of a multiple quantum well saturable absorber (>10% modulation depth and an RF current modulation. This designed laser has 20 nm tuning bandwidth in continuous wave and 10 nm tuning bandwidth in mode locking around 786 nm center wavelength at constant temperature.

  19. Suture locking of isolated internal locking knotless suture anchors is not affected by bone quality

    Science.gov (United States)

    Woodmass, Jarret M; Matthewson, Graeme; Ono, Yohei; Bois, Aaron J; Boorman, Richard S; Lo, Ian KY; Thornton, Gail M

    2015-01-01

    Purpose The purpose of this study was to evaluate the mechanical performance of different suture locking mechanisms including: i) interference fit between the anchor and the bone (eg, 4.5 mm PushLock, 5.5 mm SwiveLock), ii) internal locking mechanism within the anchor itself (eg, 5.5 mm SpeedScrew), or iii) a combination of interference fit and internal locking (eg, 4.5 mm MultiFIX P, 5.5 mm MultiFIX S). Methods Anchors were tested in foam blocks representing normal (20/8 foam) or osteopenic (8/8 foam) bone, using standard suture loops pulled in-line with the anchor to isolate suture locking. Mechanical testing included cyclic testing for 500 cycles from 10 N to 60 N at 60 mm/min, followed by failure testing at 60 mm/min. Displacement after 500 cycles at 60 N, number of cycles at 3 mm displacement, load at 3 mm displacement, and maximum load were evaluated. Results Comparing 8/8 foam to 20/8 foam, load at 3 mm displacement and maximum load were significantly decreased (Panchors that, even in part, relied on an interference fit suture locking mechanism (ie, 4.5 mm PushLock, 5.5 mm SwiveLock, 4.5 mm MultiFIX P, 5.5 mm MultiFIX S). Bone quality did not affect the mechanical performance of 5.5 mm SpeedScrew anchors which have an isolated internal locking mechanism. Conclusion The mechanical performance of anchors that relied, even in part, on interference fit were affected by bone quality. Isolated internal locking knotless suture anchors functioned independently of bone quality. Anchors with a combined type (interference fit and internal locking) suture locking mechanism demonstrated similar mechanical performance to isolated internal locking anchors in osteopenic foam comparing similar sized anchors. Clinical relevance In osteopenic bone, knotless suture anchors that have an internal locking mechanism (isolated or combined type) may be advantageous for secure tendon fixation to bone. PMID:26124683

  20. Class-A mode-locked lasers: Fundamental solutions

    Science.gov (United States)

    Kovalev, Anton V.; Viktorov, Evgeny A.

    2017-11-01

    We consider a delay differential equation (DDE) model for mode-locked operation in class-A semiconductor lasers containing both gain and absorber sections. The material processes are adiabatically eliminated as these are considered fast in comparison to the delay time for a long cavity device. We determine the steady states and analyze their bifurcations using DDE-BIFTOOL [Engelborghs et al., ACM Trans. Math. Software 28, 1 (2002)]. Multiple forms of coexistence, transformation, and hysteretic behavior of stable steady states and fundamental periodic regimes are discussed in bifurcation diagrams.

  1. Endodontic Treatment of the Mandibular First Molar with Six Roots Canals – Two Case Reports and Literature Review

    Science.gov (United States)

    Anderson, Craig

    2015-01-01

    The most common configuration of the mandibular first molar is the presence of two roots and three root canals. The objective of this work is to present two rare anatomic configurations with six root canals on two mandibular left first molars diagnosed during endodontic therapy. Root canal therapy was performed using a dental operating microscope. Ultrasonic troughing in the grooves in between the mesial root canals and in between the distal root canals was able to show the middle root canals. Large samples population characterization researches and systematic reviews were unable to detect a single case of six root canals configuration in a mandibular first molar in their investigations. Although it is a rare configuration, a six root canal configuration is possible to be found in the mandibular first molar. Three different pulp chamber configurations are possible to be found. Two or three roots may be present and the root configuration more common in the mesial root is the Type 8 and Type 12 for the distal root. Some concepts about the required technique to approach these cases are also debated. PMID:26023651

  2. Wave Mechanics of the Vestibular Semicircular Canals.

    Science.gov (United States)

    Iversen, Marta M; Rabbitt, Richard D

    2017-09-05

    The semicircular canals are biomechanical sensors responsible for detecting and encoding angular motion of the head in 3D space. Canal afferent neurons provide essential inputs to neural circuits responsible for representation of self-position/orientation in space, and to compensatory circuits including the vestibulo-ocular and vestibulo-collic reflex arcs. In this work we derive, to our knowledge, a new 1D mathematical model quantifying canal biomechanics based on the morphology, dynamics of the inner ear fluids, and membranous labyrinth deformability. The model takes the form of a dispersive wave equation and predicts canal responses to angular motion, sound, and mechanical stimulation. Numerical simulations were carried out for the morphology of the human lateral canal using known physical properties of the endolymph and perilymph in three diverse conditions: surgical plugging, rotation, and mechanical indentation. The model reproduces frequency-dependent attenuation and phase shift in cases of canal plugging. During rotation, duct deformability extends the frequency bandwidth and enhances the high frequency gain. Mechanical indentation of the membranous duct at high frequencies evokes traveling waves that move away from the location of indentation and at low frequencies compels endolymph displacement along the canal. These results demonstrate the importance of the conformal perilymph-filled bony labyrinth to pressure changes and to high frequency sound and vibration. Published by Elsevier Inc.

  3. How to bond to root canal dentin

    Science.gov (United States)

    Nica, Luminita; Todea, Carmen; Furtos, Gabriel; Baldea, Bogdan

    2014-01-01

    Bonding to root canal dentin may be difficult due to various factors: the structural characteristic of the root canal dentin, which is different from that of the coronal dentin; the presence of the organic tissue of the dental pulp inside the root canal, which has to be removed during the cleaning-shaping of the root canal system; the smear-layer resulted after mechanical instrumentation, which may interfere with the adhesion of the filling materials; the type of the irrigants used in the cleaning protocol; the type of the sealer and core material used in the obturation of the endodontic space; the type of the materials used for the restoration of the endodontically treated teeth. The influence of the cleaning protocol, of the root canal filling material, of the type of the adhesive system used in the restoration of the treated teeth and of the region of the root canal, on the adhesion of several filling and restorative materials to root canal dentin was evaluated in the push-out bond strength test on 1-mm thick slices of endodontically treated human teeth. The results showed that all these factors have a statistically significant influence on the push-out bond strength. Formation of resin tags between radicular dentin and the investigated materials was observed in some of the samples at SEM analysis.

  4. The anatomical perspective of human occipital condyle in relation to the hypoglossal canal, condylar canal, and jugular foramen and its surgical significance

    Directory of Open Access Journals (Sweden)

    Ranjana Verma

    2016-01-01

    Conclusion: The OC and related structures such as HC, CC, and JF are likely to have variations in respect to morphometry and morphology. This study may prove helpful to neurosurgeons operating in this field, especially during TCA where neurovascular structures emerging from these canals and foramen are more vulnerable to injury.

  5. Actively mode-locked Tm(3+)-doped silica fiber laser with wavelength-tunable, high average output power.

    Science.gov (United States)

    Kneis, Christian; Donelan, Brenda; Berrou, Antoine; Manek-Hönninger, Inka; Robin, Thierry; Cadier, Benoît; Eichhorn, Marc; Kieleck, Christelle

    2015-04-01

    A diode-pumped, actively mode-locked high-power thulium (Tm3+)-doped double-clad silica fiber laser is demonstrated, providing an average output power in mode-locked (continuous wave) operation of 53 W (72 W) with a slope efficiency of 34% (38%). Mode-locking in the 6th-harmonic order was obtained by an acousto-optic modulator driven at 66 MHz without dispersion compensation. The shortest measured output pulse width was 200 ps. Owing to a diffraction grating as cavity end mirror, the central wavelength could be tuned from 1.95 to 2.13 μm. The measured beam quality in mode-locked and continuous wave operation has been close to the diffraction limit.

  6. Usefulness and limitations of neuroradiological examinations in lumbar canal stenosis

    Energy Technology Data Exchange (ETDEWEB)

    Nishi, Shogo; Hanakita, Junya; Suwa, Hideyuki; Ohta, Fumito; Sakaida, Hiroshi (Shizuoka General Hospital (Japan))

    1989-09-01

    Since 1983, we have performed 434 spinal surgery operations. Among them are included 51 cases of lumbar canal stenosis. For these 51 cases, we performed several neuroradiological examinations, such as lumbar plain X-ray, myelography, metrizamide-CT scan (Met-CT) and magnetic resonance imaging (MRI). On myelography, these 51 patients were divided into three types; a complete block type with 29 patients, soy-beans type with 7 patients and strangulation type with 15 patients. Met CT was performed in 37 cases. In both strangulation type and soy-beans type which had been showed through myelography, Met-CT could clearly demonstrate the subarachnoid space, and several structures around the lumbar spinal canal could be clearly identified. In cases which myelography revealed as complete-block type, we identified two subtypes. In the first type subarachnoid space was clearly demonstrated by Met-CT. The second type was comprised of those cases where Met-CT scan could not demonstrate subarachnoid space at all. MRI was performed on 21 patients. MRI clearly showed the anatomical relationship of disc, subarachnoid space, yellow ligament and hypertrophied bony structure. MRI was thus able to bring useful information about lumbar canal stenosis even in cases where Met-CT gave little information due to the lack of metrizamide penetration of the stenotic subarachnoid space. (J.P.N.).

  7. Mandibular Canal Enlargement: Clinical and Radiological Characteristics

    Directory of Open Access Journals (Sweden)

    Chong Jun Ai

    2017-01-01

    Full Text Available Enlargement of the mandibular canal is a rare radiological finding. Clinically, it may or may not be associated with sensory deficits. We report four cases of widening of the mandibular canal observed with various methods of imaging with different clinical characteristics. We describe this unique radiological finding and elaborate the importance of quality assessment of the imaging that is vital for accurate diagnosis and treatment planning. Clinicians should be mindful when assessing the imaging whenever the size of the mandibular canal is implicated. The case ranged from a benign tumor to malignancy, radiological errors, and artifacts. A more superior imaging or treatment modality was necessary to ascertain the diagnosis.

  8. Single visit root canal treatment: a prospective study.

    Science.gov (United States)

    Edionwe, J I; Shaba, O P; Umesi, D C

    2014-01-01

    The aim was to determine the success rate of single visit root canal treatment (RCT) and thus encourage clinicians to offer this treatment option appropriately. This was a longitudinal clinical study involving all teeth of the secondary dentition except third molars in the upper and lower jaws. Teeth having irreversible pulpitis, pulp necrosis or periapical periodontitis were included in the study. RCT and obturation was done at a single visit. The patients were monitored over 6 months. Forty-five teeth were treated in 21 females and 24 males, aged 18-56 years (34.4+/-12.7). Preoperatively, pain was present in 84.4%, tenderness to percussion in 53.3%, and periapical radiolucency in 24.4% teeth. Forty percent had irreversible pulpitis and 60% had apical periodontitis. Post-operatively, pain reduced to 51.1% on day 1, 15.5% at 1 week, and 0% for the rest of the period. Tenderness to percussion reduced to 15.6% at 1 week and 0% by 1 month. Periapical radiolucency reduced to 9.5% at 6 months. Favorable outcome of 33.3% was recorded on day 1 and increased to 90.5% at 6 months. Six months success rate for teeth which had irreversible pulpitis was 100% and 83.3% for apical periodontitis. The mean time needed to complete a single visit RCT ranged from 77 min for a tooth having one canal to 132 min for one having four canals. Single visit RCT is a viable treatment option for teeth having irreversible pulpitis or apical periodontitis irrespective of tooth type or number of canals. A lot of patients are lost to follow-up visits for teeth requiring RCT once the pulp is extirpated at the first visit due to cessation of pain, subsequently leading to treatment failure. Single visit endodontics eliminates the need for follow-up visits and improves treatment prognosis.

  9. Calcium hydroxide has limited effectiveness in eliminating bacteria from human root canal.

    Science.gov (United States)

    Balto, Khaled A

    2007-01-01

    Searches of Cochrane Central Register of Controlled Trials (CENTRAL), Medline, Embase, six thesis databases (Networked Digital Library of Theses and Dissertations, Proquest Digital Dissertations, OAIster, Index to Theses, Australian Digital Thesis program and Dissertation.com) and one conference report database (BIOSIS Previews) were undertaken. There were no language restrictions. Studies were included in which participants had a noncontributory medical history, presented with mature teeth and radiographic evidence of periapical bone loss (as an indication of pre-operative canal infection), whose selected root canals had not previously received any endodontic treatment, and who had undergone nonsurgical root canal treatment during the study in which calcium hydroxide had also been used to seal in the canals. In addition, it was required that microbiological sampling had been undertaken during the course of treatment, before canal preparation, after canal preparation and after canal medication. Aerobic and anaerobic culturing techniques were performed on all samples. The treatment outcomes were stated in terms of positive and negative canal cultures. All data were extracted in the same manner using a standardised data extraction sheet. Between-study heterogeneity was assessed using the standard chi-squared test or Q-statistic. The principal measure of treatment effect (antibacterial efficacy) was risk difference, which is normally defined as the risk in the experimental group minus risk in the control group. For the purpose of this study, it is given as the difference in the proportion of bacteria-positive cultures pre- and post-medication. Out of the eight studies (257 cases) included, one study used a small control group (in which canals were left empty, and no intracanal medicament was used between appointments). The other seven studies simply compared the frequency of positive cultures before and after calcium hydroxide medication. Six studies demonstrated a

  10. Scanning electron microscopy investigation of canal cleaning after canal preparation with nickel titanium files

    Directory of Open Access Journals (Sweden)

    Živković Slavoljub

    2010-01-01

    Full Text Available Introduction. Root canal preparation is the most important phase of endodontic procedure and it consists of adequate canal space cleaning and shaping. In recent years, rotary instruments and techniques have gained importance because of the great efficacy, speed and safety of the preparation procedure. Objective. The aim of this research was to investigate the influence of different NiTi files on the canal wall cleaning quality, residual dentine debris and smear layer. Methods. The research was conducted on extracted human teeth in vitro conditions. Teeth were divided in 7 main groups depending on the kind of instruments used for root canal preparation: ProTaper, GT, ProFile, K-3, FlexMaster, hand ProTaper and hand GT. Root canal preparation was accomplished by crown-down technique. Prepared samples were assessed on scanning electron microscopy JEOL, JSM-6460 LV. The evaluation of dentine debris was done with 500x magnification, and the evaluation of smear layer with 1,000 times magnification. Quantitive assessment of dentine debris and smear layer was done according to the criteria of Hulsmann. Results. The least amount of debris and smear layer has been found in canals shaped with ProFile instruments, and the largest amount in canals shaped with FlexMaster instruments. Canal cleaning efficacy of hand GT and ProTaper files has been similar to cleaning efficacy of rotary NiTi files. Statistic analysis has shown a significant difference in amount of dentine debris and smear layer on the canal walls between sample groups shaped with different instruments. Conclusion. Completely clean canals have not been found in any tested group of instruments. The largest amount of debris and smear layer has been found in the apical third of all canals. The design and the type of endodontic instruments influence the efficacy of the canal cleaning.

  11. [Effect comparison of arachnoid cysts in sacral canal].

    Science.gov (United States)

    Wang, Baichuan; Shao, Zengwu; Wu, Hongbin; Yang, Shuhua; Wu, Yongchao; Ma, Zhilin; Yu, Peng

    2010-02-01

    To evaluate the clinical outcomes of two different surgical treatments for arachnoid cysts in sacral canal. From January 2004 to March 2009, 55 cases of arachnoid cysts in the sacral canal were treated by traditional simple sacral laminectomies with resection of the cysts (group A, 25 cases) and novel CT-guided percutaneous fibrin glue therapy of arachnoid cysts (group B, 30 cases). Of them, there were 23 males and 32 females, aging 15-66 years with an average of 42.6 years; the duration of symptoms was 6 months to 15 years with an average of 3.5 years. L5-S1 was involved in 22 cases, S1,2 in 25 cases, S2,3 in 12 cases, S2 in 8 cases, and presacral in 2 cases. The size of cysts was 1.5 cm x 1.0 cm to 6.0 cm x 2.8 cm. The MRI examination showed that all patients had cysts in the sacral canal. There were no significant difference (P > 0.05) in sex, ages, disease duration and cysts size between two groups. Preoperative data and postoperative lumbosacral pain and function improvement were analyzed and compared between two groups. All operations were performed successfully. The operative time, blood loss and hospitalization days of group B were significantly less than those of group A (P root irritation (8 cases) occurred; in group B, mild meningitis (3 cases) and low grade fever (5 cases) occurred. Except for nerve injury, other complications were cured after symptomatic management. During the follow-up, 2 recurrent cases were found in group A and 1 case in group B. Of them, 2 recurrent cases were treated with CT-guided percutaneous fibrin glue therapy of arachnoid cysts, and cysts disappeared. For two groups, there were significant differences in Oswestry functional disability index and visual analogue scale score between preoperation and postoperation (P cysts in the sacral canal is a mini-invasive, safe, effective, and economical method, it may be better choices for the treatment of arachnoid cysts in the sacral canal.

  12. Incidence of accessory canals in Japanese anterior maxillary teeth following root canal filling ex vivo.

    Science.gov (United States)

    Adorno, C G; Yoshioka, T; Suda, H

    2010-05-01

    To investigate the vertical and horizontal distribution and the incidence of accessory canals in Japanese maxillary anterior teeth following root filling. The study included maxillary teeth; 69 central incisors, 61 lateral incisors and 31 canines. After the canal systems had been dyed and root canal instrumentation had been carried out, all prepared canals were filled with gutta-percha without using sealer. Transparent specimens were then obtained and examined with a digital microscope for horizontal and vertical distributions of accessory canals. The incidence of teeth with accessory canals in the apical 3 mm was 46%, 29% and 38% for the maxillary central incisors, lateral incisors and canines, respectively. The horizontal distribution was mainly buccal for central incisors, palatal for lateral incisors and distal and palatal for canines. There was a significant difference (P < 0.05) between the apical 3 mm and the rest of the root (16%, 20% and 19% for the maxillary central incisors, lateral incisors and canines, respectively) in terms of the presence of accessory canals. A high percentage of accessory canals can be found in apical 3 mm of the root. The horizontal distribution of accessory canals differed amongst the tooth types studied.

  13. Canal and isthmus debridement efficacy using a sonic irrigation technique in a closed-canal system.

    Science.gov (United States)

    Johnson, Meenal; Sidow, Stephanie J; Looney, Stephen W; Lindsey, Kimberly; Niu, Li-na; Tay, Franklin R

    2012-09-01

    This in vitro study compared debridement efficacies of a sonic irrigation technique (Vibringe; Cavex Holland BV, Haarlem, The Netherlands) with side-vented needle irrigation (SNI) in the mesiobuccal root of maxillary first molars. Twenty roots with narrow isthmuses (≤ 1/4 canal diameter) were selected using micro-computed tomography scanning. Collagen solution was injected into canals/isthmuses and reconstituted with NH(4)OH to simulate canal debris. Each root was sealed apically and embedded in polyvinyl siloxane simulating a closed-canal system. Canals were instrumented to size 40/.04 taper 1 mm short of the anatomic apex. The final irrigation was performed with the Vibringe or SNI. Roots were demineralized, sectioned at 6 levels (1.2-3.2 mm) from the anatomic apex, and stained using Masson trichrome stain. The areas occupied by canals and isthmus and the debris-containing areas were statistically analyzed with repeated-measures analyses using "irrigation technique" as the between factor and "canal level" as the within factor (α = 0.05). Canals had significantly more debris at 1.2 and 1.6 mm (P .05). Considerably more debris remained at 1.2 and 2.0 mm for the Vibringe (P < .05). A significant difference was observed between the canal and the isthmus (P < .001). There is no difference between the Vibringe and SNI in their overall debridement efficacy in apical one third of the mesiobuccal root of maxillary first molars. Published by Elsevier Inc.

  14. Semicircular canal modeling in human perception.

    Science.gov (United States)

    Asadi, Houshyar; Mohamed, Shady; Lim, Chee Peng; Nahavandi, Saeid; Nalivaiko, Eugene

    2017-07-26

    The human vestibular system is a sensory and equilibrium system that manages and controls the human sense of balance and movement. It is the main sensor humans use to perceive rotational and linear motions. Determining an accurate mathematical model of the human vestibular system is significant for research pertaining to motion perception, as the quality and effectiveness of the motion cueing algorithm (MCA) directly depends on the mathematical model used in its design. This paper describes the history and analyses the development process of mathematical semicircular canal models. The aim of this review is to determine the most consistent and reliable mathematical semicircular canal models that agree with experimental results and theoretical analyses, and offer reliable approximations for the semicircular canal functions based on the existing studies. Selecting and formulating accurate mathematical models of semicircular canals are essential for implementation into the MCA and for ensuring effective human motion perception modeling.

  15. The non-Boussinesq lock exchange problem

    Science.gov (United States)

    Linden, Paul; Lowe, Ryan; Rottman, James

    2000-11-01

    The results of an experimental study of the non-Boussinesq lock exchange problem are described. The experiments were performed in a rectangular channel using water and a Sodium Iodide solution as the two fluids, which gave a maximum density difference of about 60experiments is to resolve some recent controversy about how gravity currents evolve from a flow at rest to the well-known steady-state gravity current made famous by Benjamin (1968). It has been argued, based on two-dimensional shallow-water theory, that Benjamin’s steady-state energy-conserving gravity current cannot evolve from the lock-exchange (or any physically reasonable) initial conditions. The experiments show that this is not true. A theory for the non-Boussinesq problem is derived that is valid for the lock-exchange problem for large times after the flow is initiated. This theory requires the formulation of a two-layer theory for hydraulic jumps in non-Boussinesq fluids. The results of the model are compared with our lock-exchange experiments and with two previous non-Boussinesq sets of lock exchange experiments, both of which use a combination of exotic gases or gases and liquids as the working fluids, with good qualitative agreement.

  16. Comparision of the expandable nail with locked nail in the treatment ...

    African Journals Online (AJOL)

    Background: Expandable nails achieve stability only by hydraulic expansion; therefore suggest less radiation exposure and operation time. In this study, we aimed to compare the results of expandable femoral nails with locked intramedullary nails in the treatment of diaphyseal fractures of femur. Materials and Methods: ...

  17. Locked Intramedullary Nailing of Femur and Tibia in a Semi Urban ...

    African Journals Online (AJOL)

    Background: Long bone fractures of the extremities are increasingly becoming a common clinical presentation of the trauma patients to the emergency unit of most urban hospital in Nigeria due to increasing vehicular traffic on our roads. Locked intramedullary nailing is the gold standard for operative treatment of these ...

  18. High-power pulsed and CW diode-pumped mode-locked Nd:YAG lasers

    Science.gov (United States)

    Marshall, Larry R.; Hays, A. D.; Kaz, Alex; Kasinski, Jeff; Burnham, R. L.

    1991-01-01

    The operation of both pulsed and CW diode-pumped mode-locked Nd:YAG lasers are presented. The pulsed laser produced 1.0 mJ with pulsewidths of 90 psec at 20 Hz. The CW pumped laser produced 6 W output at 1.064 microns and 3 W output at 532 nm.

  19. High-power self-mode-locked Pr:YLF visible lasers.

    Science.gov (United States)

    Luo, Saiyu; Xu, Bin; Xu, Huiying; Cai, Zhiping

    2017-12-01

    We demonstrate efficient self-mode-locked green and red lasers with repetition rates of tens and hundreds of megahertz in a Pr:YLF crystal. Using double-end blue-diode-pumped geometry, more than 0.68 W average output power at 522 nm and more than 1.44 W at 639 nm are obtained, which are believed to be the highest average output powers for mode-locked praseodymium lasers operating in the visible wavelength region.

  20. Diode-pumped tri-wavelength synchronously mode-locked Yb,Y:CaF₂ laser.

    Science.gov (United States)

    Li, Chun; Liu, Jie; Su, Liangbi; Jiang, Dapeng; Qian, Xiaobo; Xu, Jun

    2015-11-10

    A tri-wavelength synchronous mode-locking operation of a diode-pumped Yb,Y:CaF2 laser has been investigated by using a semiconductor saturable absorber mirror at 1 μm. The tri-wavelength synchronous mode-locking pulses were centered at 1045.7, 1047.6, and 1049.5 nm. An interference pattern was obtained in the autocorrelation trace, where the beat pulse width was 3.2 ps and the repetition rate was 0.52 THz. The maximum average output power was 196 mW with pulse width 120 ps and repetition rate of 89 MHz.

  1. Estudo prospectivo de avaliação de dor e incapacidade de pacientes operados de estenose de canal lombar com seguimento mínimo de dois anos Estudio prospectivo de la evaluación del dolor e incapacidad de los pacientes operados de estenosis del canal lumbar con seguimiento mínimo de dos años Prospective analysis of pain and disability of patients operated on lumbar spinal stenosis with a minimum two-year follow-up

    Directory of Open Access Journals (Sweden)

    Edgar Santiago Valesin Filho

    2009-12-01

    Full Text Available OBJETIVO: realizar uma análise prospectiva de dor e incapacidade em pacientes operados de estenose de canal lombar após dois anos do procedimento através da escala VAS e Roland Morris. MÉTODOS: trinta e oito pacientes foram avaliados por meio dos questionários em um momento pré-operatório, pós-operatório um mês, seis meses, um ano e dois anos, tendo sido realizada descompressão e artrodese com instrumentação pedicular associada. RESULTADOS: foi observado melhora nas análises comparativas de dor e incapacidade no decorrer do seguimento em relação aos valores iniciais, porém uma tendência à estabilização do quadro com sua evolução. CONCLUSÃO: o tratamento cirúrgico da estenose do canal lombar, quando criteriosamente indicado, melhora a dor e a incapacidade após dois anos de seguimento.OBJETIVO: realizar un análisis prospectivo del dolor e incapacidad en pacientes operados de estenosis del canal lumbar después de dos años del procedimiento, por medio de la escala VAS y Roland Morris. MÉTODOS: treinta y ocho pacientes fueron evaluados por medio de los cuestionarios en un momento preoperatorio, postoperatorio un mes, seis meses, un año y dos años, realizando una descompresión y artrodesis con instrumentación pedicular asociada. RESULTADOS: fue observada mejoría en los análisis comparativos de dolor e incapacidad con el decorrer de los seguimientos en relación a los valores iniciales; sin embargo, hubo una tendencia a la estabilidad del cuadro con su evolución. CONCLUSIÓN: el tratamiento quirúrgico de la estenosis del canal lumbar, con indicación criteriosa, mejora el dolor y la incapacidad después de dos años de seguimiento.OBJECTIVE: to perform a prospective analysis of pain and disability in patients operated on lumbar spine stenosis two years after the procedure by means of VAS and Roland Morris scales. METHODS: thirty-eight patients answered questions before and after the surgery, within one-month, six

  2. John Locke and the right to resistance

    Directory of Open Access Journals (Sweden)

    Jovanov Ilija D.

    2015-01-01

    Full Text Available John Locke was a great thinker and many works have been devoted to clear up his theories. One of the most significant, stated in his principal work, Two Treatises of Government, is the theory of the right to resistance. It was a bit revolutionary then, and to a large extent it is today. Domination of legal positivism is negation of that, by Locke, natural right. However, the fact is that in recent times the resistance to the established power occurs in a number of countries and in different forms, so that the idea of the right to resistance becomes live question again. In this regard it is interesting to consider Locke's viewpoint on this important issue and to determine whether his theory on the resistance is applicable in modern societies.

  3. Traumatic knee extension deficit (the locked knee)

    DEFF Research Database (Denmark)

    Helmark, I C; Neergaard, K; Krogsgaard, M R

    2007-01-01

    In the present study we investigated the validity of magnetic resonance imaging (MRI) and arthroscopy in knees with acute, traumatic extension deficit (the "locked knee"), and evaluated whether arthroscopy of knees with no mechanical pathology could be avoided by MRI evaluation. The study consisted...... of 50 patients who had an acute, traumatic extension deficit of the knee. All patients were submitted to MRI prior to arthroscopy. Following MRI and surgery, standardized forms were filled out, attempting to objectify the findings. The orthopaedic surgeon was not aware of the MRI result prior to surgery......, the following results were calculated for the overall appearance of a lesion able to cause locking: Positive predictive value = 0.85, negative predictive value = 0.77, sensitivity = 0.95, specificity = 0.53. Two knees were erroneously evaluated with no mechanical locking at MRI (one bucket-handle lesion and one...

  4. All Digital Phase-Locked Loop

    Directory of Open Access Journals (Sweden)

    Marijan Jurgo

    2013-05-01

    Full Text Available The paper reviews working principles of phase-locked loop and drawbacks of classical PLL structure in nanometric technologies. It is proposed to replace the classical structure by all-digital phase-locked loop structure. Authors described the main blocks of all-digital phase-locked loop (time to digital converter and digitally controlled oscillator and overviewed the quantization noise arising in these blocks as well as its minimization strategies. The calculated inverter delay in 65 nm CMOS technology was from 8.64 to 27.71 ps and time to digital converter quantization noise was from −104.33 to −82.17 dBc/Hz, with tres = 8.64–27.71 ps, TSVG = 143–333 ps, FREF = 20–60 MHz.Article in Lithuanian

  5. Actively mode-locked all fiber laser with cylindrical vector beam output.

    Science.gov (United States)

    Zhou, Yong; Wang, Anting; Gu, Chun; Sun, Biao; Xu, Lixin; Li, Feng; Chung, Dick; Zhan, Qiwen

    2016-02-01

    We demonstrated an all fiber actively mode-locked laser that emits a cylindrical vector beam. An intra-cavity few-mode fiber Bragg grating inscribed in a short section of four-mode fiber is employed to provide mode selection and spectrum filtering functions. Mode coupling is achieved by offset splicing between the single-mode fiber and the four-mode fiber in the laser cavity. A LiNbO3 Mach-Zehnder modulator is used to achieve active mode-locking in the laser. The laser operates at 1547 nm with 30 dB spectrum width of 0.2 nm. The mode-locked pulses have a duration of 2 ns and repetition of 12.06 MHz. Through adjusting the polarization state in the laser cavity, both radially and azimuthally polarized beams have been obtained with high mode purity.

  6. Multiwavelength mode-locked cylindrical vector beam fiber laser based on mode selective coupler

    Science.gov (United States)

    Huang, Ping; Cai, Yu; Wang, Jie; Wan, Hongdan; Zhang, Zuxing; Zhang, Lin

    2017-10-01

    We propose and demonstrate a multiwavelength mode-locked fiber laser with cylindrical vector beam generation for the first time, to the best of our knowledge. The mode-locking mechanism is based on a nonlinear polarization rotation effect in fiber, and the multiwavelength operation is contributed to by an in-line birefringence fiber filter with periodic multiple passbands, formed by incorporating a section of polarization maintaining fiber into the laser cavity with a fiber polarizer. Furthermore, by using a home-made mode selective coupler, which acts as both a mode converter from fundamental mode to higher-order mode and an output coupler, multiwavelength mode-locked cylindrical vector beams have been obtained. This may have potential applications in mode-division multiplexing optical fiber communication and material processing.

  7. 1.5-micron fiber laser passively mode-locked by gold nanoparticles saturable absorber

    Science.gov (United States)

    Ahmad, Harith; Tahrin, Rabiatul Addawiyah Azwa; Azman, Nursyafiqa; Kassim, Syara; Ismail, Mohd Afiq; Maah, Mohd Jamil

    2017-11-01

    A 1.5 μm fiber laser which was passively mode-locked by gold nanoparticles saturable absorber (SA) is proposed and demonstrated. The SA was fabricated via dripping the gold nanoparticles solution onto the fiber ferrules and left to dry. The SA has an insertion loss of 12 dB, modulation depth of 1.35% and saturation intensity of ∼ 1 GW /cm2. At sufficiently high pump power, the mode-locked operation started with some applied disturbance to the SA. The resultant mode-locked characteristics includes 6.897 MHz of repetition rate, 4.04 ps of pulsewidth, ∼ 61 dB of signal-to-noise ratio and 1.329 mW of output power.

  8. Dual-wavelength mode-locked fiber laser based on tungsten disulfide saturable absorber

    Science.gov (United States)

    Li, Xiaowen; Qian, Jianqiang; Zhao, Ruwei; Wang, Fan; Wang, Zhenyu

    2017-12-01

    We report on the generation of dual-wavelength mode-locked laser pulse in an Er-doped ring-shaped fiber cavity with WS2 nanosheets based saturable absorber (SA), emitting at wavelength of 1531.8 nm and 1556.7 nm. The WS2 nanosheets were precipitated on the head face of fiber patch cord via light precipitation method. By adjusting the polarization of lasing mode, the gain of the Er-doped fiber laser was effectively controlled and the stable dual-wavelength mode-locking operation was achieved. Our investigation revealed WS2’s extraordinary nonlinear properties, which make it an excellent material for saturable absorber for passively mode-locked fiber lasers.

  9. Controllable asymmetric phase-locked states of the fundamental active photonic dimer

    Science.gov (United States)

    Kominis, Yannis; Kovanis, Vassilios; Bountis, Tassos

    2017-10-01

    Coupled semiconductor lasers are systems possessing complex dynamics that are interesting for numerous applications in photonics. In this work, we investigate the existence and the stability of asymmetric phase-locked states of the fundamental active photonic dimer consisting of two coupled lasers. We show that stable phase-locked states of arbitrary asymmetry exist for extended regions of the parameter space of the system and that their field amplitude ratio and phase difference can be dynamically controlled by appropriate current injection. The model includes the important role of carrier density dynamics and shows that the phase-locked state asymmetry is related to operation conditions providing, respectively, gain and loss in the two lasers.

  10. Harmonic Mode-Locked Fiber Laser based on Photonic Crystal Fiber Filled with Topological Insulator Solution

    Directory of Open Access Journals (Sweden)

    Yu-Shan Chen

    2015-04-01

    Full Text Available We reported that the photonic crystal fiber (PCF filled with TI:Bi2Te3 nanosheets solution could act as an effective saturable absorber (SA. Employing this TI-PCF SA device; we constructed an ytterbium-doped all-fiber laser oscillator and achieved the evanescent wave mode-locking operation. Due to the large cavity dispersion; the fundamental mode-locking pulse had the large full width at half maximum (FWHM of 2.33 ns with the repetition rate of ~1.11 MHz; and the radio frequency (RF spectrum with signal-to-noise ratio (SNR of 61 dB. In addition; the transition dynamics from a bunched state of pulses to harmonic mode-locking (HML was also observed; which was up to 26th order.

  11. Double-locked semiconductor laser for radio-over-fiber uplink transmission.

    Science.gov (United States)

    Cui, Cuicui; Fu, Xuelei; Chan, Sze-Chun

    2009-12-15

    The nonlinear dynamics of an optically injected semiconductor laser are explored for radio-over-fiber uplink transmission. Under optical injection locking, the laser at the base station is operated in the period-one oscillation state, where its intensity oscillates at a tunable microwave frequency. When the oscillation is tuned to the subcarrier frequency, it is further locked by the uplink microwave signal. By simply using an ordinary 2.5-Gbps-grade semiconductor laser, uplink transmission of the phase-shift keying (PSK) signal at a subcarrier of 16 GHz with bit-error rate of less than 10(-11) is demonstrated experimentally. Microwave PSK to optical PSK is achieved at the double-locked laser, which allows all-optical demodulation without any high-speed microwave electronics.

  12. Technical quality of root canal fillings done in a Nigerian general dental clinic

    Directory of Open Access Journals (Sweden)

    Adebayo Ezekiel

    2012-10-01

    Full Text Available Abstract Background Previous reports indicate that worldwide, the technical quality of root canal fillings is poor. There are few reports from sub-Saharan Africa and none yet from Nigeria where most patients access treatment from non-specialists especially at general dental clinics. The aim of this study was to evaluate the technical quality of root canal fillings done in a general dental clinic with emphasis on the effects of professional experience of the operator, whether tooth was anterior or posterior and whether it was a maxillary or mandibular tooth. Methods Retrospective study of case notes and periapical radiographs of patients with completed root canal fillings seen between 2008 and 2011. Inclusion criteria included cases of primary treatment with available case notes, good quality pre-operative and post-operative periapical radiographs. Technical quality that was assessed was root canal length and homogeneity. Root canal fillings were classified either as Good Quality Endodontic Work (GQEW or Non- Good Quality Endodontic Work (NGQEW. Results Fifty-one patients aged between 8 and 54 years (mean 28 fulfilled the inclusion criteria for this study. From these, there were 62 root filled teeth giving a ratio of 1.2 root canal filled teeth per person. There were acceptable length of root canal fillings in 71% of teeth, 58.1% were homogeneous while 53.2% were GQEW. There was no statistically significant difference in whether tooth was root filled by junior or senior dentist (p = 0.43, anterior or posterior (p = 0.11. There was significant association between GQEW and maxillary teeth (p = 0.03. Conclusion This study showed that the overall technical quality of root canal fillings done by non-specialists was better than earlier reports but lower than that done by endodontists. Since many patients receive treatment from non-specialists in developing countries, it is necessary to improve technical quality of root canal fillings done

  13. Technical quality of root canal fillings done in a Nigerian general dental clinic.

    Science.gov (United States)

    Adebayo, Ezekiel Taiwo; Ahaji, Lilian Ejije; Nnachetta, Rita Nneka; Nwankwo, Olaitan; Akabogu-Okpeseyi, Nonye; Yaya, Morufu Olasunkanmi; Hussain, Nurudeen Ayoola

    2012-10-15

    Previous reports indicate that worldwide, the technical quality of root canal fillings is poor. There are few reports from sub-Saharan Africa and none yet from Nigeria where most patients access treatment from non-specialists especially at general dental clinics. The aim of this study was to evaluate the technical quality of root canal fillings done in a general dental clinic with emphasis on the effects of professional experience of the operator, whether tooth was anterior or posterior and whether it was a maxillary or mandibular tooth. Retrospective study of case notes and periapical radiographs of patients with completed root canal fillings seen between 2008 and 2011. Inclusion criteria included cases of primary treatment with available case notes, good quality pre-operative and post-operative periapical radiographs. Technical quality that was assessed was root canal length and homogeneity. Root canal fillings were classified either as Good Quality Endodontic Work (GQEW) or Non- Good Quality Endodontic Work (NGQEW). Fifty-one patients aged between 8 and 54 years (mean 28) fulfilled the inclusion criteria for this study. From these, there were 62 root filled teeth giving a ratio of 1.2 root canal filled teeth per person. There were acceptable length of root canal fillings in 71% of teeth, 58.1% were homogeneous while 53.2% were GQEW. There was no statistically significant difference in whether tooth was root filled by junior or senior dentist (p=0.43), anterior or posterior (p=0.11). There was significant association between GQEW and maxillary teeth (p=0.03). This study showed that the overall technical quality of root canal fillings done by non-specialists was better than earlier reports but lower than that done by endodontists. Since many patients receive treatment from non-specialists in developing countries, it is necessary to improve technical quality of root canal fillings done in general dental clinics. These could be through improvement in the quality of

  14. Field Measurement Test Plan to Determine Effects of Hydrokinetic Turbine Deployment on Canal Test Site in Yakima, WA, USA

    OpenAIRE

    Gunawan, Budi; Neary, Vincent S.; Roberts, Jesse; Dallman, Ann; Grovue, Shane; Mortensen, Josh; Heiner, Bryan

    2014-01-01

    The primary goal of the Department of Energy’s Water Power Program is to efficiently develop and utilize the country’s marine hydrokinetic (MHK) and conventional hydropower (CH) resources. The program has recently identified the need to better understand the potential for hydrokinetic energy development within existing canal systems that may already have integrated CH plants. Hydrokinetic (HK) turbine operation can alter water surface elevations and modify the flow in a canal. Significant wat...

  15. Frequency acquisition techniques for phase locked loop

    CERN Document Server

    Talbot, Daniel

    2012-01-01

    Many good phaselocked loops (PLL) books exist. However, how to acquire the input frequency from an unlocked state is rarely covered. This book explores the methods for achieving this locked state for a variety of conditions. Using a minimum of mathematics, it introduces engineers to performance limitations of phase/frequency detector based PLL, the quadricorrelator method for both continuous and sampled mode, sawtooth ramp-and-sample phase detector, self-sweeping self-extinguishing topology, and sweep methods using quadrature mixer based lock detection. Digital implementations versus analog are also considered.

  16. Progress as Compositional Lock-Freedom

    DEFF Research Database (Denmark)

    Carbone, Marco; Dardha, Ornela; Montesi, Fabrizio

    2014-01-01

    such definition to capture a more intuitive notion of context adequacy for checking progress. Interestingly, our new catalysers lead to a novel characterisation of progress in terms of the standard notion of lock-freedom. Guided by this discovery, we also develop a conservative extension of catalysers that does...... not depend on types, generalising the notion of progress to untyped session-based processes. We combine our results with existing techniques for lock-freedom, obtaining a new methodology for proving progress. Our methodology captures new processes wrt previous progress analysis based on session types....

  17. Locke and the education of the adolescent

    Directory of Open Access Journals (Sweden)

    Francisco T. Baciero Ruiz

    2008-12-01

    Full Text Available John Locke has been considered one of the leading figures in the His- tory of Philosophy, specially for his two famous treatises An Essay concerning Human understanding and Two Treatises on Government. None the less his work in Pedagogy, Some thougths concerning Education, is no less important, and provides the leading strings of that what ought to be the education of the gentleman, whose unavoidable foundation must be a solid education in virtue grounded in the moral principles of Christianity. Key words: Locke, Moral education, Spanish authors of the XVIth century. 

  18. Locke y la adulación

    OpenAIRE

    Tomás Chuaqui H.

    2004-01-01

    En este artículo se verifica la relevancia de un vicio político específico, la adulación, en las ideas de John Locke. Se muestra que para Locke la adulación proviene de agentes ilustrados que incitan a los aspirantes al poder recurriendo al orgullo que típicamente los caracteriza. Este vicio político, por ende, hace peligrar a los regímenes de poderes limitados y desconcentrados, ya que induce, a través del cultivo del orgullo, un deseo desmedido por el poder y el dominio sobre otros. Así, se...

  19. Drag and Torque on Locked Screw Propeller

    Directory of Open Access Journals (Sweden)

    Tomasz Tabaczek

    2014-09-01

    Full Text Available Few data on drag and torque on locked propeller towed in water are available in literature. Those data refer to propellers of specific geometry (number of blades, blade area, pitch and skew of blades. The estimation of drag and torque of an arbitrary propeller considered in analysis of ship resistance or propulsion is laborious. The authors collected and reviewed test data available in the literature. Based on collected data there were developed the empirical formulae for estimation of hydrodynamic drag and torque acting on locked screw propeller. Supplementary CFD computations were carried out in order to prove the applicability of the formulae to modern moderately skewed screw propellers.

  20. Mode-locking in coupled map lattices

    CERN Document Server

    Carretero-González, R; Vivaldi, F

    1997-01-01

    We study propagation of pulses along one-way coupled map lattices, which originate from the transition between two superstable states of the local map. The velocity of the pulses exhibits a staircase-like behaviour as the coupling parameter is varied. For a piece-wise linear local map, we prove that the velocity of the wave has a Devil's staircase dependence on the coupling parameter. A wave travelling with rational velocity is found to be stable to parametric perturbations in a manner akin to rational mode-locking for circle maps. We provide evidence that mode-locking is also present for a broader range of maps and couplings.

  1. Design of a knee orthosis locking system

    OpenAIRE

    Ramôa, Pedro Daniel Silva

    2012-01-01

    Dissertação de mestrado em Engenharia Mecatrónica The main goal of this work was to design a mechatronic locking system for a Stance Control Knee Ankle Foot Orthosis (SCKAFO). This mechanism should be able to perform two different functions. The first one is to lock the orthosis during the stance phase of human gait, in which contact between the foot and the ground exists. The second function deals with the unlock of the orthosis during the swing phase, in which there is no ...

  2. High-Order Frequency-Locked Loops

    DEFF Research Database (Denmark)

    Golestan, Saeed; Guerrero, Josep M.; Quintero, Juan Carlos Vasquez

    2017-01-01

    In very recent years, some attempts for designing high-order frequency-locked loops (FLLs) have been made. Nevertheless, the advantages and disadvantages of these structures, particularly in comparison with a standard FLL and high-order phase-locked loops (PLLs), are rather unclear. This lack...... study, and its small-signal modeling, stability analysis, and parameter tuning are presented. Finally, to gain insight about advantages and disadvantages of high-order FLLs, a theoretical and experimental performance comparison between the designed second-order FLL and a standard FLL (first-order FLL...

  3. Sound lateralization ability of patients with bilateral microtia and atresia after bilateral reconstruction of auricles and external auditory canals and fitting of new canal-type hearing aids to replace a bone conduction hearing aid.

    Science.gov (United States)

    Kaga, Kimitaka; Asato, Hirotaka

    2017-04-01

    Each of eight patients with bilateral microtia and atresia underwent bilateral reconstruction of the auricles and external auditory canals and were fitted bilateral canal-type hearing aids in the operated ears to replace a bone conduction hearing aid. The ability to discriminate inter-aural intensity difference (IID) and even inter-aural time difference (ITD) was retained in all these patients. This study studied the post-operative sound lateralization ability of patients with bilateral microtia and atresia after total reconstruction of both auricles and external auditory canals, followed by fitting of bilateral canal-type hearing aids. Eight patients with bilateral microtia and atresia ranging in age from 13-43 years were recruited in this study. Each of them underwent bilateral reconstruction of the auricles and external auditory canals and were fitted canal-type hearing aids in both the operated ears to replace a bone conduction hearing aid. A sound lateralization test was conducted to determine IID and ITD discrimination ability thresholds. In all the patients, the IID discrimination ability thresholds of the patients were more than 3-fold those of the controls, the ITD discrimination ability threshold was more than 5-fold those of controls, and binaural hearing was retained.

  4. Posterior semicircular canal dehiscence: a morphologic cause of vertigo similar to superior semicircular canal dehiscence

    Energy Technology Data Exchange (ETDEWEB)

    Krombach, G.A.; Schmitz-Rode, T.; Haage, P.; Guenther, R.W. [Department of Diagnostic Radiology, University of Technology, Pauwelstrasse 30, 52057, Aachen (Germany); DiMartino, E. [Department of Otorhinolaryngology, University of Technology, Pauwelstrasse 30, 52057, Aachen (Germany); Prescher, A. [Department of Anatomy, University of Technology, Pauwelstrasse 30, 52057, Aachen (Germany); Kinzel, S. [Department of Experimental Veterinarian Medicine, University of Technology, Pauwelstrasse 30, 52057, Aachen (Germany)

    2003-06-01

    Heading Abstract.The aim of this study was to assess imaging findings of posterior semicircular dehiscence on computed tomography and to evaluate incidence of posterior and superior semicircular canal dehiscence in patients presenting with vertigo, sensorineuronal hearing loss or in a control group without symptoms related to the inner ear. Computed tomography was performed in 507 patients presenting either with vertigo (n=128; 23 of these patients suffered also from sensorineuronal hearing loss), other symptoms related to the inner ear, such as hearing loss or tinnitus (n=183) or symptoms unrelated to the labyrinth (n=196). All images were reviewed for presence of dehiscence of the bone, overlying the semicircular canals. Twenty-nine patients had superior semicircular canal dehiscence. Of these patients, 83% presented with vertigo, 10% with hearing loss or tinnitus and the remaining 7% with symptoms unrelated to the inner ear. In 23 patients dehiscence of the posterior semicircular canal was encountered. Of these patients, 86% presented with vertigo, 9% with hearing loss or tinnitus and 5% with symptoms unrelated to the inner ear. Defects of the bony overly are found at the posterior semicircular canal, in addition to the recently introduced superior canal dehiscence syndrome. Significant prevalence of vertigo in these patients suggests that posterior semicircular canal dehiscence can cause vertigo, similar to superior semicircular canal dehiscence. (orig.)

  5. Hardware locks for a real-time Java chip multiprocessor

    DEFF Research Database (Denmark)

    Strøm, Torur Biskopstø; Puffitsch, Wolfgang; Schoeberl, Martin

    2016-01-01

    A software locking mechanism commonly protects shared resources for multithreaded applications. This mechanism can, especially in chip-multiprocessor systems, result in a large synchronization overhead. For real-time systems in particular, this overhead increases the worst-case execution time...... and may void a task set's schedulability. This paper presents 2 hardware locking mechanisms to reduce the worst-case time required to acquire and release synchronization locks. These solutions are implemented for the chip-multiprocessor version of the Java Optimized Processor. The 2 hardware locking...... mechanisms are compared with a software locking solution as well as the original locking system of the processor. The hardware cost and performance are evaluated for all presented locking mechanisms. The performance of the better-performing hardware locks is comparable with that of the original single global...

  6. Robust tilt and lock mechanism for hopping actuator

    Energy Technology Data Exchange (ETDEWEB)

    Salton, Jonathan R.; Buerger, Stephen; Dullea, Kevin J.; Marron, Lisa C.; Salisbury, Curt Michael; Spletzer, Barry Louis

    2017-02-07

    A tilt and lock apparatus that includes a tilt servomechanism, a spiral torsion spring, a lock wheel, and a lock hook is described herein. The spiral torsion spring is mechanically coupled to the tilt servomechanism and the lock wheel (which includes an opening). When a shaft is positioned through the opening, rotation of the lock wheel is in unison with rotation of the shaft. An external surface of the lock wheel includes one or more grooves. The lock hook includes a head that engages and disengages the grooves. The lock wheel is stationary when the head engages one of the grooves and is rotatable when the head disengages the grooves. The head and the grooves are geometrically aligned when engaged to prevent creation of a force that acts to disengage the head responsive to an applied force acting on the shaft.

  7. "Thoughts Concerning Education": John Locke On Teaching Speech

    Science.gov (United States)

    Baird, John E.

    1971-01-01

    Locke's suggestions for more effective speech instruction have gone largely unnoticed. Consequently, it is the purpose of this article to consider John Locke's criticisms, theory and specific methods of speech education. (Author)

  8. NRC staff review of licensee responses to pressure-locking and thermal-binding issue

    Energy Technology Data Exchange (ETDEWEB)

    Rathbun, H.J.

    1996-12-01

    Commercial nuclear power plant operating experience has indicated that pressure locking and thermal binding represent potential common mode failure mechanisms that can cause safety-related power-operated gate valves to fail in the closed position, thus rendering redundant safety-related systems incapable of performing their safety functions. In Generic Letter (GL) 95-07, {open_quotes}Pressure Locking and Thermal Binding of Safety-Related Power-Operated Gate Valves,{close_quotes} the U.S. Nuclear Regulatory Commission (NRC) staff requested that nuclear power plant licensees take certain actions to ensure that valves susceptible to pressure locking or thermal binding are capable of performing their safety functions within the current licensing bases of the facility. The NRC staff has received summary information from licensees in response to GL 95-07 describing actions they have taken to prevent the occurrence of pressure locking and thermal binding. The NRC staff has developed a systematic process to help ensure uniform and consistent review of licensee submittals in response to GL 95-07.

  9. Widely tunable 2  μm continuous-wave and mode-locked fiber laser.

    Science.gov (United States)

    Ma, Wanzhuo; Wang, Tianshu; Zhang, Yan; Liu, Peng; Su, Yuwei; Jia, Qingsong; Bi, Mingzhe; Zhang, Peng; Jiang, Huilin

    2017-04-20

    We propose and experimentally demonstrate a widely tunable mode-locked thulium-doped fiber laser. The laser can operate at both continuous-wave and mode-locked states at different pump power levels. A classic nonlinear polarization rotation structure is employed to obtain the passive mode-locked laser. A birefringence Lyot filter as a fiber comb filter is used to expand the tuning range. Thanks to the filtering component, the tuning range of the continuous-wave laser can reach 127 nm (1823-1950 nm). The tuning ranges of the single-wavelength and dual-wavelength mode-locked lasers are 94 nm (1835-1929 nm) and 87 nm (1831-1918 nm), respectively, with a 3.085 MHz repetition rate and 75 ps pulse width.

  10. Low threshold diode-pumped picosecond mode-locked Nd:YAG laser with a semiconductor saturable absorber mirror

    Science.gov (United States)

    Eshghi, M. J.; Majdabadi, A.; Koohian, A.

    2017-01-01

    In this paper, a low threshold diode pumped passively mode-locked Nd:YAG laser has been demonstrated by using a semiconductor saturable absorber mirror. The threshold power for continuous-wave mode-locking is relatively low, about 3.2 W. The resonator stability across the pump power has been analytically examined. Moreover, the mode overlap between the pump beam and the laser fundamental mode has been simulated by MATLAB software. Adopting Z-shaped resonator configuration and suitable design of the resonator’s arm lengths, has enabled the author to prepare mode-locking conditions, and obtain 40 ps pulses with 112 MHz pulse repetition rate. The laser output was stable without any Q switched instability. To the best of our knowledge, this is the lowest threshold for CW mode-locking operation of a Nd:YAG laser.

  11. Dynamic Self-Locking of an OEO Containing a VCSEL

    Science.gov (United States)

    Strekalov, Dmitry; Matsko, Andrey; Yu, Nan; Savchenkov, Anatoliy; Maleki, Lute

    2009-01-01

    A method of dynamic self-locking has been demonstrated to be effective as a means of stabilizing the wavelength of light emitted by a vertical-cavity surface-emitting laser (VCSEL) that is an active element in the frequency-control loop of an optoelectronic oscillator (OEO) designed to implement an atomic clock based on an electromagnetically- induced-transparency (EIT) resonance. This scheme can be considered an alternative to the one described in Optical Injection Locking of a VCSEL in an OEO (NPO-43454), NASA Tech Briefs, Vol. 33, No. 7 (July 2009), page 33. Both schemes are expected to enable the development of small, low-power, high-stability atomic clocks that would be suitable for use in applications involving precise navigation and/or communication. To recapitulate from the cited prior article: In one essential aspect of operation of an OEO of the type described above, a microwave modulation signal is coupled into the VCSEL. Heretofore, it has been well known that the wavelength of light emitted by a VCSEL depends on its temperature and drive current, necessitating thorough stabilization of these operational parameters. Recently, it was discovered that the wavelength also depends on the microwave power coupled into the VCSEL. This concludes the background information. From the perspective that led to the conception of the optical injection-locking scheme described in the cited prior article, the variation of the VCSEL wavelength with the microwave power circulating in the frequency-control loop is regarded as a disadvantage and optical injection locking is a solution of the problem of stabilizing the wavelength in the presence of uncontrolled fluctuations in the microwave power. The present scheme for dynamic self-locking emerges from a different perspective, in which the dependence of VCSEL wavelength on microwave power is regarded as an advantageous phenomenon that can be exploited as a means of controlling the wavelength. The figure schematically depicts

  12. Mode-locked frequency doubled Nd:YAG laser

    Science.gov (United States)

    Brookman, J. S.

    1976-01-01

    The design, fabrication, test, and delivery of two mode-locked, frequency doubled Nd:YAG laser systems are described. Each system was comprised of two units, the laser head and optics on an Invar plate and the electronics control unit in a relay rack chassis panel. Laser number one operated at a repetition rate of 400 MHz and was designed for use in an optical communication system. Laser number two operated at 200 MHz repetition rate and was designed for optical ranging and target signature experiments. Both lasers had a pulse width of 200 ps at the 10% amplitude points at 1.064 micrometer wavelength (150 ps at 0.532 micrometers) with an amplitude stability of + or - 4%. Output power exceeded the design goals.

  13. Femtosecond mode-locked Nd(3+)-doped Ba(Zr,Mg,Ta)O(3) ceramic laser.

    Science.gov (United States)

    Higashi, Y; Nakao, H; Shirakawa, A; Ueda, K; Kaminskii, A A; Kuretake, S; Kintaka, Y; Murayama, K; Tanaka, N

    2015-08-15

    We have demonstrated continuous wave (CW) laser operation and the first, to the best of our knowledge, sub-200 fs mode-locked laser operation of Nd(3+)-doped Ba(Zr,Mg,Ta)O(3) ceramic. Its disordered crystalline nature exhibits a broad gain bandwidth of 30 nm with a high-emission cross section. It also has higher thermal and mechanical properties than Nd:glass. In CW operation, a maximum output power of 1.5 W under 6.2 W of absorbed pump power was obtained. In mode-locked operation, a pulse duration of 196 fs with an average power of 60 mW was successfully achieved. The laser spectrum straddled both fluorescence peaks of A-site and B-site Nd(3+) ions.

  14. Ultra-broadband dissipative soliton and noise-like pulse generation from a normal dispersion mode-locked Tm-doped all-fiber laser.

    Science.gov (United States)

    Sobon, Grzegorz; Sotor, Jaroslaw; Martynkien, Tadeusz; Abramski, Krzysztof M

    2016-03-21

    We report generation of ultra-broadband dissipative solitons and noise-like pulses from a simple, fully fiberized mode-locked Tm-doped fiber laser. The oscillator operates in the normal net dispersion regime and is mode-locked via nonlinear polarization evolution. Depending on the cavity dispersion, the laser was capable of generating 60 nm or 100 nm broad dissipative solitons. These are the broadest spectra generated from a normal dispersion mode-locked Tm-doped fiber laser so far. The same oscillator might also operate in the noise-like pulse regime with extremely broad emission spectra (over 300 nm), which also significantly outperforms the previous reports.

  15. Mental foramen and lingual vascular canals of mandible on MDCT images: anatomical study and review of the literature.

    Science.gov (United States)

    Direk, Filiz; Uysal, Ismihan Ilknur; Kivrak, Ali Sami; Fazliogullari, Zeliha; Unver Dogan, Nadire; Karabulut, Ahmet Kagan

    2017-04-13

    The mental foramen and lingual vascular canals are related to vessels and nerves in the mandibular body. The aim of the present study was to determine the number and location of these structures and to make measurements of them. The archived Multidetector Computed Tomography images of 100 adult (15- to 70-year-old) patients were evaluated retrospectively. The diameters of the mental foramens and their distances from the front, back, upper and lower reference points were measured. The distribution of mental foramens with respect to the teeth was also researched. The presence of lingual vascular canals, and the number of median and lateral canals was determined, and the length of the median lingual vascular canals measured. All measurement parameters were analyzed by gender, side and age group. Eleven patients demonstrated a total of 15 accessory mental foramen. Median lingual vascular canals were observed in 100% of cases, with lateral lingual vascular canals determined in 32%. Significant differences were observed in the results of different gender groups (P foramen was determined mostly in males, and unilaterally on the right side; also, the distances of mental foramen, except the distance from the back border of the mandible (P foramen, as well as the presence, position and size of lingual vascular canals can be clearly investigated by multidetector computed tomography. A preoperative knowledge of the positions of neurovascular and bone structures is very important for preventing complications that may occur during or after operations.

  16. An ex vivo comparison of detection ability of three methods in discovering of MB2 canal in maxillary molars

    Directory of Open Access Journals (Sweden)

    Ghorbanzadeh A.

    2009-11-01

    Full Text Available "nBackground and Aim: A considerable percentage of failure in Endodontic treatments in maxillary molars is attributed to undiscovered second mesiobuccal canal (MB2.There are different methods for discovering and accessing to this canal. The purpose of this ex vivo study was to compare the detection ability of three methods (direct look, fiberoptic loup and surgical microscope to find MB2 after troughing with ultrasonic. "nMaterials and Methods: In this experimental study, we selected 90 extracted maxillary molars (45 first and 45 second molars in which after access cavity preparation MB2 canal was not discovered by direct vision and endodontic explorer. They were divided into 3 groups (n=30. The dentinal shelf between mesiobuccal and palatal canals was eliminated by an endodontic ultrasonic tip (troughing. After that, first group was searched by direct vision, second group by a loup and fiberoptic light and third group by dental operating microscope. Data were analyzed, specificity and sensitivity were calculated. "nResults: The results showed that 21%, 61%, and 92% of MB2 canals after troughing was found by direct vision, fiberoptic loup, and surgical microscope, respectively. "nConclusion: Based on the results of this study, surgical microscope and loup with fiberoptic are preferred methods for discovering MB2 canal. Troughing with ultrasonic can help find MB2 canal in all methods.

  17. Theory of Passively Mode-Locked Photonic Crystal Semiconductor Lasers

    DEFF Research Database (Denmark)

    Heuck, Mikkel; Blaaberg, Søren; Mørk, Jesper

    2010-01-01

    We report the first theoretical investigation of passive mode-locking in photonic crystal mode-locked lasers. Related work has investigated coupled-resonator-optical-waveguide structures in the regime of active mode-locking [Opt. Express 13, 4539-4553 (2005)]. An extensive numerical investigation...

  18. A formal reduction for lock-free parallel algorithms

    NARCIS (Netherlands)

    Gao, H.; Hesselink, W.H.; Alur, R; Peled, DA

    2004-01-01

    On shared memory multiprocessors, synchronization often turns out to be a performance bottleneck and the source of poor fault-tolerance. Lock-free algorithms can do without locking mechanisms, and are therefore desirable. Lock-free algorithms are hard to design correctly, however, even when

  19. 49 CFR 236.387 - Movable bridge locking.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Movable bridge locking. 236.387 Section 236.387 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... and Tests § 236.387 Movable bridge locking. Movable bridge locking shall be tested at least once a...

  20. Locke on Education and the Rights of Parents

    Science.gov (United States)

    Tuckness, Alex

    2010-01-01

    John Locke is often taken to be a staunch defender of parents' rights in the realm of education. In fact, Locke's pedagogical reasons for preferring home education to school education do not necessarily apply to similar choices in modern contexts. Locke's political argument for defining education as a duty of parents rather than the state does not…

  1. 30 CFR 56.12068 - Locking transformer enclosures.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Locking transformer enclosures. 56.12068 Section 56.12068 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... § 56.12068 Locking transformer enclosures. Transformer enclosures shall be kept locked against...

  2. Lumbar spinal canal size of sciatica patients

    Energy Technology Data Exchange (ETDEWEB)

    Hurme, M.; Alaranta, H.; Aalto, T.; Knuts, L.R.; Vanharanta, H.; Troup, J.D.G. (Turku City Hospital (Finland). Dept. of Surgery; Social Insurance Institution, Turku (Finland). Rehabilitation Research Centre; Helsinki Univ. (Finland). Dept. of Physical Medicine and Rehabilitation; Liverpool Univ. (UK). Dept. of Orthopaedic and Accident Surgery)

    Seven measures at the three lowest lumbar interspaces were recorded from conventional radiographs of the lumbar spines of 160 consecutive patients with low back pain and sciatica admitted for myelography and possible surgery. Eighty-eight patients were operated upon for disc herniation, and of the conservatively-treated 72 patients, 18 had a pathologic and 54 a normal myelogram. The results were evaluated after one year using the occupational handicap scales of WHO. Correlations of radiographic measures to stature were moderate and to age small. After adjusting for stature and age, only the male interpedicular distances and the antero-posterior diameter of intervertebral foramen at L3 were greater than those of females. The males with a pathologic myelogram had smaller posterior disc height at L3 and a smaller interarticular distance at L3 and L4 than those with normal myelogram, likewise the midsagittal diameter at L3 and L4 in females. In all patients other measures besides posterior disc height were smaller than those for low back pain patients (p<0.001) or for cadavers (p<0.001). The only correlation between measures and clinical manifestations was between pedicular length at L3 and limited straight leg raising. Where the disc material had been extruded into the spinal canal, the interpedicular distance was significantly wider. Only anterior disc height at L3 revealed differences between good and poor outcome one year after surgery, as did the interarticular distance at S1 in patients with normal myelogram after conservative treatment. (orig.).

  3. Aircraft Detectors, Trap Triggers and Combination Locks

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 5; Issue 2. Aircraft Detectors, Trap Triggers and Combination Locks - Functional Diversity of Insect Mechanosensory Hairs. Jürgen Tautz. General Article Volume 5 Issue 2 February 2000 pp 32-38 ...

  4. El derecho de propiedad en John Locke

    OpenAIRE

    Jorge Luis Toyama Miyagusuku

    1998-01-01

    El tema que abordaremos en esta monografía se contrae en determinar los principales aspectos de la teoría sobre el derecho de propiedad del inglés John Locke (Wrington, 1632-1704), en su obra«Segundo Ensayo sobre el GobiernoCivil».John

  5. Phase locked loops design, simulation, and applications

    CERN Document Server

    Best, Roland E

    2007-01-01

    The Definitive Introduction to Phase-Locked Loops, Complete with Software for Designing Wireless Circuits! The Sixth Edition of Roland Best's classic Phase-Locked Loops has been updated to equip you with today's definitive introduction to PLL design, complete with powerful PLL design and simulation software written by the author. Filled with all the latest PLL advances, this celebrated sourcebook now includes new chapters on frequency synthesis…CAD for PLLs…mixed-signal PLLs…all-digital PLLs…and software PLLs_plus a new collection of sample communications applications. An essential tool for achieving cutting-edge PLL design, the Sixth Edition of Phase-Locked Loops features: A wealth of easy-to-use methods for designing phase-locked loops Over 200 detailed illustrations New to this edition: new chapters on frequency synthesis, including fractional-N PLL frequency synthesizers using sigma-delta modulators; CAD for PLLs, mixed-signal PLLs, all-digital PLLs, and software PLLs; new PLL communications ap...

  6. A locked nucleic Acid-based nanocrawler

    DEFF Research Database (Denmark)

    Astakhova, I Kira; Pasternak, Karol; Campbell, Meghan A

    2013-01-01

    Herein we introduce a novel fluorescent LNA/DNA machine, a nanocrawler, which reversibly moves along a directionally polar complementary road controlled by affinity-enhancing locked nucleic acid (LNA) monomers and additional regulatory strands. Polyaromatic hydrocarbon (PAH) dyes attached to 2...

  7. Locking plate fixation for proximal humerus fractures.

    LENUS (Irish Health Repository)

    Burke, Neil G

    2012-02-01

    Locking plates are increasingly used to surgically treat proximal humerus fractures. Knowledge of the bone quality of the proximal humerus is important. Studies have shown the medial and dorsal aspects of the proximal humeral head to have the highest bone strength, and this should be exploited by fixation techniques, particularly in elderly patients with osteoporosis. The goals of surgery for proximal humeral fractures should involve minimal soft tissue dissection and achieve anatomic reduction of the head complex with sufficient stability to allow for early shoulder mobilization. This article reviews various treatment options, in particular locking plate fixation. Locking plate fixation is associated with a high complication rate, such as avascular necrosis (7.9%), screw cutout (11.6%), and revision surgery (13.7%). These complications are frequently due to the varus deformation of the humeral head. Strategic screw placement in the humeral head would minimize the possibility of loss of fracture reduction and potential hardware complications. Locking plate fixation is a good surgical option for the management of proximal humerus fractures. Complications can be avoided by using better bone stock and by careful screw placement in the humeral head.

  8. Theory of mode-locked semiconductor lasers.

    NARCIS (Netherlands)

    Leegwater, J.A.

    1996-01-01

    We present a theoretical study of semiconductor mode-locked lasers at a phenomenological level. We use the slow absorber model of New and Haus, but extend the analysis by taking into account the shift in the gain maximum due to the changing number of carriers. In our analysis of the resulting

  9. School Choice Litigation after "Zelman" and "Locke"

    Science.gov (United States)

    Liekweg, John A.

    2004-01-01

    In the past 2 years, the United States Supreme Court has decided two important cases that will bear directly on legislation and litigation involving school choice programs that provide financial aid to parents of children attending religious schools. Those cases are "Zelman v. Simmons-Harris" (2002) and "Locke v. Davey" (2004).…

  10. Locks & keys service moves to building 55

    CERN Multimedia

    2012-01-01

    Please note that as of July 12 Locks & keys service will be at building 55 second floor. The opening hours are as follows: 08:30 am to 12:30 pm - 1:30 pm to 5:30 pm. The procedures and rules relating to applications for key and cylinder have not changed. GI-IS Group

  11. "Locke, penseur subversif dans les manuscrits clandestins"

    DEFF Research Database (Denmark)

    Schøsler, Jørn

    2007-01-01

    Der gives en analyse af John Lockes subversive indflydelse på den franske Oplysning via de hemmeligt cirkulerende manuskripter fra århundredets begyndelse med kredsen omkring grev Boulainvillers ("Coterie Boulainviller") til århundredets slutning med kredsen omkring baron d'Holbach og Naigeon....

  12. Democratising Political Powers through Locke's Doctrine of ...

    African Journals Online (AJOL)

    ... their views on political powers, including their 'prerogative powers'; no longer as their individual rights but as the 'federative powers' of the people; aware that after all, legitimate sovereignty belongs to the people. Key Words: Doctrine of Prerogative, Prerogative Powers, John Locke, Political Powers, Despotic Monarchies, ...

  13. Lock-free parallel garbage collection

    NARCIS (Netherlands)

    H. Gao; J.F. Groote (Jan Friso); W.H. Hesselink (Wim)

    2005-01-01

    htmlabstract This paper presents a lock-free parallel algorithm for mark&sweep garbage collection (GC) in a realistic model using synchronization primitives compare-and-swap (CAS) and load-linked/store-conditional (LL/SC) offered by machine architectures. Mutators and collectors can simultaneously

  14. Rehabilitation of Navigation Lock Walls: Case Histories

    Science.gov (United States)

    1987-12-01

    CONCRETE CONTAINS CHERT, LIMESTONE RIVER GRAVEL...APPROVED JOINT FILLER RESURFACING CONCRETE Figure 94. Horizontal dummy joint design, Lock No. 1, Mississippi River 141 a. Outside view b. Inside...upper service gate sill. Concrete mixture proportions for a l-eu yd batch were as follows: Type I portland cement, lb Natural sand, lb Limestone

  15. A New Perspective on Job Lock

    Science.gov (United States)

    Huysse-Gaytandjieva, Anna; Groot, Wim; Pavlova, Milena

    2013-01-01

    This paper analyses the situation when employees fail to adapt to overall job dissatisfaction. By combining the existing knowledge in economics on job lock and in psychology on employees' feeling of being "stuck" at work, the paper explains why some employees fail to adapt when dissatisfied with their job. Thus, the paper aims to expand…

  16. 49 CFR 236.742 - Dog, locking.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Dog, locking. 236.742 Section 236.742 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION..., MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.742 Dog...

  17. Experimental demonstration of frequency-degenerate bright EPR beams with a self-phase-locked OPO.

    Science.gov (United States)

    Keller, G; D'Auria, V; Treps, N; Coudreau, T; Laurat, J; Fabre, C

    2008-06-23

    We report the first experimental observation of bright EPR beams produced by a type-II optical parametric oscillator operating above threshold at frequency degeneracy. The degenerate operation is obtained by introducing a birefringent plate inside the cavity resulting in phase locking. After filtering the pump noise, which plays a critical role, continuous-variable EPR correlations between the orthogonally polarized signal and idler beams are demonstrated.

  18. Management of C-shaped canals: Two case reports

    Directory of Open Access Journals (Sweden)

    Nilesh Suryakant Kadam

    2013-01-01

    Full Text Available A C-shaped canal with varying configuration is commonly observed in single-rooted mandibular second molars. Cooke and Cox (1979 first documented the C-shaped canal in endodontic literature. The presence of high incidence of transverse anastomoses, lateral canals, and apical deltas makes it difficult to clean and seal the root canal system in these teeth. The main reason for failure in endodontic treatment of mandibular second molars is the inability to detect the presence of C-shaped canals prior to an endodontic therapy. This case report presents successful management of two rare cases of C-shaped canal configurations.

  19. Function of lateral line canal morphology.

    Science.gov (United States)

    Klein, Adrian; Bleckmann, Horst

    2015-01-01

    Fish perceive water motions and pressure gradients with their lateral line. Lateral line information is used for prey detection, spatial orientation, predator avoidance, schooling behavior, intraspecific communication and station holding. The lateral line of most fishes consists of superficial neuromasts (SNs) and canal neuromasts (CNs). The distribution of SNs and CNs shows a high degree of variation among fishes. Researchers have speculated for decades about the functional significance of this diversity, often without any conclusive answers. Klein et al. (2013) examined how tubules, pore number and pore patterns affect the filter properties of lateral line canals in a marine teleost, the black prickleback (Xiphister atropurpureus). A preliminary mathematical model was formulated and biomimetic sensors were built. For the present study the mathematical model was extended to understand the major underlying principle of how canal dimensions influence the filter properties of the lateral line. Both the extended mathematical model and the sensor experiments show that the number and distribution of pores determine the spatial filter properties of the lateral line. In an environment with little hydrodynamic noise, simple and complex lateral line canals have comparable response properties. However, if exposed to highly turbulent conditions, canals with numerous widely spaced pores increase the signal to noise ratio significantly. © 2014 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and Wiley Publishing Asia Pty Ltd.

  20. Hydraulic Modeling of Lock Approaches

    Science.gov (United States)

    2016-08-01

    attributed to the closure were estimated at $5M per day (Hite et al. 2006). Accident frequency might be reduced if tow boat pilots are provided...these cases, the water is sufficiently deep such that hydrodynamic effects of gate operation on the tow are negligible when compared to other factors...transport of conservative constituents, such as dye clouds, as well as sediment transport that is coupled to bed and hydrodynamic changes. This code is

  1. Automated Identification of MHD Mode Bifurcation and Locking in Tokamaks

    Science.gov (United States)

    Riquezes, J. D.; Sabbagh, S. A.; Park, Y. S.; Bell, R. E.; Morton, L. A.

    2017-10-01

    Disruption avoidance is critical in reactor-scale tokamaks such as ITER to maintain steady plasma operation and avoid damage to device components. A key physical event chain that leads to disruptions is the appearance of rotating MHD modes, their slowing by resonant field drag mechanisms, and their locking. An algorithm has been developed that automatically detects bifurcation of the mode toroidal rotation frequency due to loss of torque balance under resonant braking, and mode locking for a set of shots using spectral decomposition. The present research examines data from NSTX, NSTX-U and KSTAR plasmas which differ significantly in aspect ratio (ranging from A = 1.3 - 3.5). The research aims to examine and compare the effectiveness of different algorithms for toroidal mode number discrimination, such as phase matching and singular value decomposition approaches, and to examine potential differences related to machine aspect ratio (e.g. mode eigenfunction shape variation). Simple theoretical models will be compared to the dynamics found. Main goals are to detect or potentially forecast the event chain early during a discharge. This would serve as a cue to engage active mode control or a controlled plasma shutdown. Supported by US DOE Contracts DE-SC0016614 and DE-AC02-09CH11466.

  2. Wideband-tuneable, nanotube mode-locked, fibre laser.

    Science.gov (United States)

    Wang, F; Rozhin, A G; Scardaci, V; Sun, Z; Hennrich, F; White, I H; Milne, W I; Ferrari, A C

    2008-12-01

    Ultrashort-pulse lasers with spectral tuning capability have widespread applications in fields such as spectroscopy, biomedical research and telecommunications. Mode-locked fibre lasers are convenient and powerful sources of ultrashort pulses, and the inclusion of a broadband saturable absorber as a passive optical switch inside the laser cavity may offer tuneability over a range of wavelengths. Semiconductor saturable absorber mirrors are widely used in fibre lasers, but their operating range is typically limited to a few tens of nanometres, and their fabrication can be challenging in the 1.3-1.5 microm wavelength region used for optical communications. Single-walled carbon nanotubes are excellent saturable absorbers because of their subpicosecond recovery time, low saturation intensity, polarization insensitivity, and mechanical and environmental robustness. Here, we engineer a nanotube-polycarbonate film with a wide bandwidth (>300 nm) around 1.55 microm, and then use it to demonstrate a 2.4 ps Er(3+)-doped fibre laser that is tuneable from 1,518 to 1,558 nm. In principle, different diameters and chiralities of nanotubes could be combined to enable compact, mode-locked fibre lasers that are tuneable over a much broader range of wavelengths than other systems.

  3. Narrow linewidth 578 nm light generation using frequency-doubling with a waveguide PPLN pumped by an optical injection-locked diode laser.

    Science.gov (United States)

    Kim, Eok Bong; Lee, Won-Kyu; Park, Chang Yong; Yu, Dai-Hyuk; Park, Sang Eon

    2010-05-10

    This study demonstrates 578 nm yellow light generation with a narrow linewidth using a waveguide periodically poled lithium niboate (PPLN) and an optical injection-locked diode laser. The frequency of an external cavity diode laser used as a master laser operating at 1156 nm in optical injection-locking mode was locked into a high-finesse cavity with the Pound-Drever-Hall technique, which results in a linewidth reduction of the master laser. The linewidth of the master laser was estimated to be approximately 1.6 kHz. In an effort to amplify the optical power, a distributed feed-back laser was phase-locked to the master laser by an optical injection-locking technique. A waveguide PPLN was used for second harmonic generation. Frequency-doubled yellow light of approximately 2.4 mW was obtained with a conversion efficiency of 6.5%. (c) 2010 Optical Society of America.

  4. Comparative study of locking plates in mandibular reconstruction after ablative tumor surgery: THORP versus UniLOCK system.

    Science.gov (United States)

    Gellrich, Nils-Claudius; Suarez-Cunqueiro, Maria Mercedes; Otero-Cepeda, Xose Luis; Schön, Ralf; Schmelzeisen, Rainer; Gutwald, Ralf

    2004-02-01

    This retrospective study compared 2 types of rigid locking plates (THORP and UniLOCK; Stratec Medical, Oberdorf, Switzerland) in 107 patients undergoing reconstruction for bridging mandibular defects following ablative tumor surgery. From January 1993 to December 2000, 107 patients were reconstructed following ablative tumor surgery with 57 THORP plates and 50 UniLOCK plates. Study follow-up ranged from 18 to 87 months (average, 32 months). Complications were categorized into delayed wound healing, infection, plate exposure, and plate fracture, taking into account the type and timing of reconstruction. Overall type and number of complications show no statistically significant differences between THORP and UniLOCK groups. Infection was the most frequent type of complication (THORP, 30; UniLOCK, 32). Others included delayed wound healing (THORP, 13; UniLOCK, 12), plate exposure (THORP, 8; UniLOCK, 7), and plate fracture (THORP, 5; UniLOCK, 1). Plates were removed in 22 THORP and 11 UniLOCK plates. The most frequent reason for plate removal in both groups was infection. Other reasons for plate removal include tumor recurrence, plate fracture, plate exposure, or a combination of reasons. THORP and UniLOCK plates do not present statistically significant differences in the parameters studied. Nevertheless, the UniLOCK group had slightly better results. Considering that the THORP system is much bulkier and its screws bigger, our results lead to the conclusion that bridging osteosynthesis with a 2.4 UniLOCK system is adequate for plate reconstruction of mandibular defects.

  5. Diagnostic value of saccoradiculography and of cat scan to detect stenosis of the lumbar canal

    Energy Technology Data Exchange (ETDEWEB)

    Arrault, I.; Benoist, M.; Rocolle, J.; Busson, J.; Lassale, B.; Deburge, A.

    1987-10-01

    Radiculographic X-rays and CAT scans of 60 patients operated on for stenosis of the lumbar canal were analysed separately and retrospectively by rheumatologists, a radiologist and surgeons working jointly, without knowledge of findings revealed by surgery. Comparison of findings with a detailed surgical report reveals that in the case of central lumbar canal stenosis, CAT scan provides a higher degree of reliability (72%) in diagnosis than does radiculography (56%). With lateral stenosis of the lateral cleft, reliability of both tests is identical (62%). The diagnostic deficiencies of these two examinations are discussed as well as diagnostic criteria employed and possible avenues of research. Currently, in the case of stenosis of the lumbar canal, it is still necessary to perform both of these examinations in combination and to accept the fact that, in certain cases, only one of the two tests reveals the stenosis, to be able to attain a preoperative rate of correct diagnosis greater than 80%.

  6. Wiener-Hopf optimal control of a hydraulic canal prototype with fractional order dynamics.

    Science.gov (United States)

    Feliu-Batlle, Vicente; Feliu-Talegón, Daniel; San-Millan, Andres; Rivas-Pérez, Raúl

    2017-06-26

    This article addresses the control of a laboratory hydraulic canal prototype that has fractional order dynamics and a time delay. Controlling this prototype is relevant since its dynamics closely resembles the dynamics of real main irrigation canals. Moreover, the dynamics of hydraulic canals vary largely when the operation regime changes since they are strongly nonlinear systems. All this makes difficult to design adequate controllers. The controller proposed in this article looks for a good time response to step commands. The design criterium for this controller is minimizing the integral performance index ISE. Then a new methodology to control fractional order processes with a time delay, based on the Wiener-Hopf control and the Padé approximation of the time delay, is developed. Moreover, in order to improve the robustness of the control system, a gain scheduling fractional order controller is proposed. Experiments show the adequate performance of the proposed controller. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  7. Risk analysis of failure of root canal treatment for teeth with inaccessible apical constriction.

    Science.gov (United States)

    Negishi, Jun; Kawanami, Masamitsu; Ogami, Eriko

    2005-05-01

    The risk of failure of root canal therapy was assessed in teeth with inaccessible apical constriction and factors influencing treatment outcome in these teeth were analyzed. From the same 57 patients, one tooth with inaccessible apical constriction (n=57) and one tooth with adequate accessibility (n=57) were included in this retrospective investigation. Cox regression analysis was used to analyze factors that may have influenced the outcome one or more years after obturation. These factors included inaccessibility, systemic disease, canal curvature, preoperative periradicular lesion, widening of periodontal ligament space, patient gender and age, size of master apical file, preoperative pulp vitality, years of operator experience and obturation length. Inaccessible apical constriction was a significant factor related to outcome (odds ratio, 5.301). Preoperative presence of periradicular lesion significantly influenced the outcome in cases with inaccessibility (odds ratio, 4.448). Inaccessibility increases the risk of root canal therapy failure particularly in teeth with preoperative periradicular lesion.

  8. Meatoplasty in Canal wall down Surgery: Our Experience and Literature Review.

    Science.gov (United States)

    Memari, Faramarz; Maleki Delarestaghi, Mojtaba; Mir, Parisa; GolMohammadi, Mohammad; Shams Koushki, Ehsan

    2017-01-01

    Meatoplasty is the final and essential step in performing effective canal wall down surgery for chronic otitis media. In this article we review some previous techniques and discuss our preferred method. In this observational case series study, we used this technique in 53 patients (28 male and 25 female) between January 2005 and January 2008. Our survey was completed in 31 patients. Twenty-six patients (83.9%) said their ear appeared normal after the procedure, but five patients (16.1%) complained of some minor change in the shape of their ear. Twenty-nine patients (93.5%) had a completely wide ear canal. The ear canal had some degree of stenosis in two patients (6.5%) post-operatively. This technique offers good functional and cosmetic results with minimal manipulation and minimal anatomic disruption.

  9. Meatoplasty in Canal wall down Surgery: Our Experience and Literature Review

    Directory of Open Access Journals (Sweden)

    Faramarz Memari

    2017-01-01

    Full Text Available Introduction: Meatoplasty is the final and essential step in performing effective canal wall down surgery for chronic otitis media. In this article we review some previous techniques and discuss our preferred method. Materials and Methods: In this observational case series study, we used this technique in 53 patients (28 male and 25 female between January 2005 and January 2008. Our survey was completed in 31 patients. Results: Twenty-six patients (83.9% said their ear appeared normal after the procedure, but five patients (16.1% complained of some minor change in the shape of their ear. Twenty-nine patients (93.5% had a completely wide ear canal. The ear canal had some degree of stenosis in two patients (6.5% post-operatively. Conclusion: This technique offers good functional and cosmetic results with minimal manipulation and minimal anatomic disruption.

  10. Study of root canal accessibility in human primary molars.

    Science.gov (United States)

    Aminabadi, Naser A; Farahani, Ramin M Z; Gajan, Esrafil B

    2008-03-01

    The aim of the present study was to provide a general scheme for pulpectomy of primary molars that may be useful for decision-making about negotiation of root canals and selection of appropriate instruments. A total of 160 vital primary molars in 85 patients (40 males, 45 females) aged 4-6 years were selected. After taking primary radiographs, local anesthesia was induced, and the teeth were isolated using a rubber dam. Canal accessibility index (CAI) and tooth accessibility index (TAI) were calculated according to initial file size. Mandibular first molars had either three canals (79.2%) or four canals (20.8%), and all second molars had four canals. Maxillary first molars had three canals and second molars had either three canals (70.9%) or four canals (29.1%). Lower accessibility of the mandibular first molar distobuccal root accounted for the lower accessibility of these teeth in comparison with mandibular second molars. While three-canal maxillary second molars were more accessible due to the lower accessibility of the distobuccal canal of the maxillary first molar, poor accessibility of the distal canal in four-canal second molars was responsible for the difficult accessibility of these teeth. In conclusion, it seems that the accessibility of a single canal in each tooth determines the difficulty of accessibility for any given tooth. Moreover, while primary second molars are more accessible than first molars, all of them are negotiable.

  11. Root canal debridement: an online study guide.

    Science.gov (United States)

    2008-05-01

    The Editorial Board of the Journal of Endodontics has developed a literature-based study guide of topical areas related to endodontics. This study guide is intended to give the reader a focused review of the essential endodontic literature and does not cite all possible articles related to each topic. Although citing all articles would be comprehensive, it would defeat the idea of a study guide. This section will present root canal debridement including subdivisions on canal access, canal debridement, orifice enlargement and preflaring, crown-down technique, balanced force, nickel titanium and other shape memory alloys, rotary engine-driven techniques, endodontic instruments, irrigation, electronic apex locators, sonics/ultrasonics, smear layer, and intracanal medicaments.

  12. The 'Amstel Canal' in Amsterdam Canal construction as part of the medieval reclamation and drainage system of the Western Netherlands wilderness

    Science.gov (United States)

    Abrahamse, Jaap-Evert; Kosian, Menne; Weerts, Henk

    2013-04-01

    Usually, Amsterdam is presented as a river city, with the river Amstel as the trade route towards its hinterland, the IJ sea-branch as the portal to the world and its Dam as a focal point of transshipment and trade. Geomorphological, sedimentological, historical and historical-geographical evidence however, points towards the straight part of the Amstel, now located in Amsterdam, as a drainage canal that was dug in the aftermath of the 'Great Reclamation' of the 11th and 12th centuries. During this period, large parts of the wilderness in Utrecht and Holland were cultivated and put to agricultural use. Prior to the 'Great Reclamations', large oligotrophic (Sphagnum) peat bogs drained by small rivers were characteristic of the entire region. All along the straight Amstel canal, Sphagnum peat is found, which is indicative of the area's former peat bog conditions. The 'Amstel Canal' connected two natural meandering watercourses, one at the north and one at the south of the canal. The soil along both watercourses exists of eutrophic peat, which is indicative of repeated natural flooding. This is a strong indication of the anthropogenous origin of the straight part of the Amstel. The reason for digging the Amstel canal was not to create better trade links; it was a local component of a solution for major regional drainage problems in the provinces of Utrecht and Holland. These problems arose from the silting up of the Rhine rivermouth around 1100AD. Because of this, the precipitation surplus of the entire region could not be drained to the North Sea by this route anymore. This led to increased flooding and subsequently to conflicts between the rulers of Holland and Utrecht. In 1165AD, these conflicts reached a point where the Holy Roman Emperor intervened. The ruling of Barbarossa eventually led to a compromise: Utrecht and Holland redirected the entire drainage system of the region from the North Sea to the Zuiderzee in a concerted effort. This operation consisted of

  13. Fluoroscopic freehand and electromagnetic-guided targeting system for distal locking screws of humeral intramedullary nail.

    Science.gov (United States)

    Persiani, P; Gurzi, M; Moreschini, O; Di Giacomo, G; Villani, C

    2017-04-01

    The current techniques used to lock distal screws for the nailing of long bone fractures expose the surgeons, radiologists and patients to a hearty dose of ionizing radiation. The Sureshot™ Distal Targeting System is a new technique that, with the same results, allows for shorter surgery times and, consequently, less exposure to radiation. The study was performed on 59 patients (34 males and 25 females) with a simple humerus fracture diagnosis, type 1.2.A according to the AO classification, who were divided into two groups. Group 1 was treated with ante-grade intramedullary nailing with distal locking screws inserted with a freehand technique. Group 2 was treated with the intramedullary nail using the Sureshot™ Distal Targeting System. Two intra-operative time parameters were evaluated in both groups: the time needed for the positioning of the distal locking screws and the time of exposure to ionizing radiations during this procedure. Group 2 showed a lower average distal locking time compared to group 1 (645.48″ vs. 1023.57″) and also a lower average time of exposure to ionizing radiation than in group 1 (4.35″ vs. 28.96″). The Sureshot™ Distal Targeting System has proven to be equally effective when compared to the traditional techniques, with the added benefits of a significant reduction in both surgical time and risk factors related to the exposure to ionizing radiation for all the operating room staff and the patient.

  14. Role of magnetic resonance imaging in the clinical management of the acutely locked knee

    Energy Technology Data Exchange (ETDEWEB)

    McNally, Eugene G.; Nasser, Khalid N.; Dawson, Stewart; Goh, Leslie A. [Department of Musculoskeletal Radiology, Nuffield Orthopaedic Centre and Oxford Radcliffe Hospital, Oxford, OX3 7LD (United Kingdom)

    2002-10-01

    To explore prospectively the hypothesis that MRI of the acutely locked knee can alter surgical decision-making.Design and patients. The study group comprised patients with a clinical diagnosis of knee locking requiring arthroscopy. The decision to carry out arthroscopy was made by an experienced consultant orthopaedic surgeon specialising in trauma and recorded in the patient's notes prior to MRI. Preoperative MRI was carried out using a 1.5 T system. The management was altered from surgical to conservative treatment in 20 (48%) patients on the basis of the MR findings. Arthroscopy was limited to patients with an MR diagnosis of a mechanical block, usually a displaced meniscal tear or loose body. Both patient groups were followed clinically until symptoms resolved.Results. Forty-two patients were entered into the study. MRI identified a mechanical cause for locking in 22 patients (21 avulsion meniscal tears and 1 loose body). All were confirmed at arthroscopy. Twenty patients were changed from operative to non-operative treatment on the basis of the MRI findings. One patient in this group required a delayed arthroscopy for an impinging anterior cruciate ligament stump. The sensitivity/specificity/accuracy of MRI in identifying patients who require arthroscopy was therefore 96%/100%/98% respectively.Conclusion. MRI can successfully segregate patients with a clinical diagnosis of mechanical locking into those who have a true mechanical block and those who can be treated conservatively. MRI should precede arthroscopy in this clinical setting. (orig.)

  15. Intervertebral biomechanics of locking compression plate monocortical fixation of the canine cervical spine.

    Science.gov (United States)

    Agnello, Kimberly A; Kapatkin, Amy S; Garcia, Tanya C; Hayashi, Kei; Welihozkiy, Anja T; Stover, Susan M

    2010-12-01

    To evaluate the use of a locking compression plate (LCP) with monocortical screw purchase for stabilization of the canine cervical spine. Experimental study. Cadaveric canine cervical spine specimens (n = 7). Flexion and extension bending moments were applied to canine cadaveric specimens (C3-C6) in 4-point bending, before and after creation of a ventral slot at C4-C5, and after fixation with a 5 hole, 3.5 mm LCP with monocortical screw placement. Screw placement and penetration into the vertebral canal were determined by radiography. Range of motion, stiffness, and energy for passive physiologic loads were determined for the C3-C4, C4-C5, and C5-C6 vertebral motion units (VMU). Monotonic failure properties were determined for cervical extension. Effects of treatments on biomechanical variables were assessed using repeated measures analysis of variance and least square means (P ≤ .05). The ventral slot procedure increased range of motion at the treated VMU. Plate fixation decreased range of motion, increased stiffness, and decreased energy at the treated VMU. No changes were observed at adjacent VMUs. None of the screws penetrated the vertebral canal. Mean (± SD) yield bending moment of plate stabilized, slotted spines was 15.6 ± 4.6 N m. LCP fixation with monocortical screws stabilized the canine cervical spine. © Copyright 2010 by The American College of Veterinary Surgeons.

  16. Effect of two contemporary root canal sealers on root canal dentin microhardness.

    Science.gov (United States)

    Khallaf, Maram E

    2017-01-01

    Successful root canal treatment depends on proper cleaning, disinfecting and shaping of the root canal space. Pulpless teeth have lower dentin microhardness value compared to that of vital teeth. A material which can cause change in dentin composition may affect the microhardness. Thus the aim of this study was to evaluate and compare the effect of two root canal sealers on dentin microhardness. Forty two single rooted teeth were selected and divided into 3 equal groups; Apexit, iRootSP and control groups (n=14) Each group was then divided into 2 subgroups according to the post evaluation period; 1 week and 2 months (n=7). Root canal procedure was done in the experimental groups and obturation was made using either; Apexit, iRootSP or left unprepared and unobturated in the control group. Roots were sectioned transversely into cervical, middle and apical segments. The three sections of each root were mounted in a plastic chuck with acrylic resin. The coronal dentin surfaces of the root segments werepolished. Microhardness of each section was measured at 500 µm and 1000 µm from the canal lumen. Four way-ANOVA revealed that different tested sealer materials, canal third, measuring distance from the pulp and time as independent variables had statistically non significant effect on mean microhardness values (VHN) at p≤0.001. Among iRootSP groups there was a statistically significant difference between iRoot SP at coronal root portion (87.79±17.83) and iRoot SP at apical root portion (76.26±9.33) groups where (p=0.01). IRoot SP at coronal canal third had higher statistically significant mean microhardness value (87.79±17.83) compared to Apexit at coronal third (73.61±13.47) where (p=0.01). Root canal sealers do not affect dentin microhardness. Key words:Root canal, dentin, sealers, microhardness, bioceramic.

  17. Cochlear implant outcomes in patients with superior canal dehiscence

    NARCIS (Netherlands)

    Puram, Sidharth V.; Roberts, Daniel S.; Niesten, Marlien E F|info:eu-repo/dai/nl/377125202; Dilger, Amanda E.; Lee, Daniel J.

    2015-01-01

    Objective: To determine whether adult cochlear implant (CI) users with superior canal dehiscence syndrome (SCDS) or asymptomatic superior semicircular canal dehiscence (SCD) have different surgical, vestibular, and audiologic outcomes when compared to CI users with normal temporal bone anatomy.

  18. Surgical endodontic management of infected lateral canals of maxillary incisors.

    Science.gov (United States)

    Jang, Ji-Hyun; Lee, Jung-Min; Yi, Jin-Kyu; Choi, Sung-Baik; Park, Sang-Hyuk

    2015-02-01

    This case report presents surgical endodontic management outcomes of maxillary incisors that were infected via the lateral canals. Two cases are presented in which endodontically-treated maxillary central incisors had sustained lateral canal infections. A surgical endodontic treatment was performed on both teeth. Flap elevation revealed vertical bone destruction along the root surface and infected lateral canals, and microscopy revealed that the lateral canals were the origin of the lesions. After the infected lateral canals were surgically managed, both teeth were asymptomatic and labial fistulas were resolved. There were no clinical or radiographic signs of surgical endodontic management failure at follow-up visits. This case report highlights the clinical significance and surgical endodontic management of infected lateral canal of maxillary incisor. It is important to be aware of root canal anatomy variability in maxillary incisors. Maxillary central incisors infected via the lateral canal can be successfully managed by surgical endodontic treatment.

  19. Intradermal melanocytic nevus of the external auditory canal.

    Science.gov (United States)

    Alves, Renato V; Brandão, Fabiano H; Aquino, José E P; Carvalho, Maria R M S; Giancoli, Suzana M; Younes, Eduado A P

    2005-01-01

    Intradermal nevi are common benign pigmented skin tumors. Their occurrence within the external auditory canal is uncommon. The clinical and pathologic features of an intradermal nevus arising within the external auditory canal are presented, and the literature reviewed.

  20. Radiographic versus electronic root canal working length determination

    Directory of Open Access Journals (Sweden)

    Lumnije Kqiku

    2011-01-01

    Conclusions: The present ex vivo study showed that electronic root canal working length determination is not superior to radiographic methods. Both methods provided a good performance in determining the root canal working length.

  1. Report from the Panama Canal Stakeholder Working Group.

    Science.gov (United States)

    2013-03-01

    This project assists the Texas Department of Transportation (TxDOT) in assessing the potential impacts of the Panama Canal expansion on Texas ports and the landside transportation system. TxDOT formed a Panama Canal Stakeholder Working Group (PCSWG) ...

  2. On the Performance of Distributed Lock-Based Synchronization

    Science.gov (United States)

    Lubowich, Yuval; Taubenfeld, Gadi

    We study the relation between two classical types of distributed locking mechanisms, called token-based locking and permission-based locking, and several distributed data structures which use locking for synchronization. We have proposed, implemented and tested several lock-based distributed data structures, namely, two different types of counters called find&increment and increment&publish, a queue, a stack and a linked list. For each one of them we have determined what is the preferred type of lock to be used as the underling locking mechanism. Furthermore, we have determined which one of the two proposed counters is better to be used either as a stand-alone data structure or when used as a building block for implementing other high level data structures.

  3. Analyzing endosonic root canal file oscillations: an in vitro evaluation.

    Science.gov (United States)

    Lea, Simon C; Walmsley, A Damien; Lumley, Philip J

    2010-05-01

    Passive ultrasonic irrigation may be used to improve bacterial reduction within the root canal. The technique relies on a small file being driven to oscillate freely within the canal and activating an irrigant solution through biophysical forces such as microstreaming. There is limited information regarding a file's oscillation patterns when operated while surrounded by fluid as is the case within a canal root. Files of different sizes (#10 and #30, 27 mm and 31 mm) were connected to an ultrasound generator via a 120 degrees file holder. Files were immersed in a water bath, and a laser vibrometer set up with measurement lines superimposed over the files. The laser vibrometer was scanned over the oscillating files. Measurements were repeated 10 times for each file/power setting used. File mode shapes are comprised of a series of nodes/antinodes, with thinner, longer files producing more antinodes. The maximum vibration occurred at the free end of the file. Increasing generator power had no significant effect on this maximum amplitude (p > 0.20). Maximum displacement amplitudes were 17 to 22 microm (#10 file, 27 mm), 15 to 21 microm (#10 file, 31 mm), 6 to 9 microm (#30 file, 27 mm), and 5 to 7 microm (#30, 31 mm) for all power settings. Antinodes occurring along the remaining file length were significantly larger at generator power 1 than at powers 2 through 5 (p < 0.03). At higher generator powers, energy delivered to the file is dissipated in unwanted vibration resulting in reduced vibration displacement amplitudes. This may reduce the occurrence of the biophysical forces necessary to maximize the technique's effectiveness. Copyright (c) 2010 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  4. Viscoelastic assessment of anal canal function using acoustic reflectometry

    DEFF Research Database (Denmark)

    Mitchell, Peter J; Klarskov, Niels; Telford, Karen J

    2012-01-01

    Anal acoustic reflectometry is a new reproducible technique that allows a viscoelastic assessment of anal canal function. Five new variables reflecting anal canal function are measured: the opening and closing pressure, opening and closing elastance, and hysteresis.......Anal acoustic reflectometry is a new reproducible technique that allows a viscoelastic assessment of anal canal function. Five new variables reflecting anal canal function are measured: the opening and closing pressure, opening and closing elastance, and hysteresis....

  5. Detecting the apical constriction in curved mandibular molar roots--preflared versus nonflared canals.

    Science.gov (United States)

    Khan, Irfan Ullah; Sobhi, Muhammad Baksh

    2003-01-01

    Achieving and maintaining correct working length is critical to success in endodontic therapy. This involves placing the file in to the canal to feel the apical constriction, preparing the canal upto that extent and then filling the entire canal upto the apical constriction with gutta percha points. Detection of the apical constriction is affected if the coronal part of the canal is narrow or obstructed due to dentine deposition. This usually happens in curved canals and gives the operator a false feeling of the apical constriction. The aim of this study was to compare the effect on tactile detection of apical constriction in mandibular molars with curved roots, between the preflared and non-flared root canals. This study was carried out at Armed Forces Institute of Dentistry, Rawalpindi, Pakistan, from February to April 2002. Seventy patients coming for the endodontic treatment of their mandibular first molars were selected. The study included only mandibular molars with curved mesial canals. The total no of patients were divided equally into the preflared and non-flared groups. In both groups a No. 15 K file was used to detect or feel the apical constriction but in the preflared group the coronal portion of the canal was flared/prepared using Hedstrom files (No. 25-55) and Gates Glidden Drills No. 02 to No. 05 before inserting the No. 15 file. The tooth was radiographed at this moment and the distance between the tip of the file and the radiographic apex was measured. The location of the tip was classified as: a) Within 1 mm of the radiographic apex, b) Under extended, more than 1 mm of radiographic apex, and c) Over extended, beyond the radiographic apex. In the non-flared group 31.4% belonged to group 'a', 40% to group 'b', and 28.57% to group 'c'. In the flared group 80% belonged to group 'a', 5.7% to group 'b', and 14.28% to group 'c'. Results of this study suggest that preflaring greatly improves the tactile sense to feel the apical constriction in curved

  6. 75 FR 45477 - Drawbridge Operation Regulation; Company Canal, Bourg, LA

    Science.gov (United States)

    2010-08-03

    ..., 2010. The closure is necessary in order to replace electrical conductors and conduit throughout the..., Louisiana. The deviation is necessary to perform electrical rehabilitation work on the bridge. This...

  7. 76 FR 21253 - Drawbridge Operation Regulation; Company Canal, Lockport, LA

    Science.gov (United States)

    2011-04-15

    ... closure is necessary in order to replace electrical conductors and conduit throughout the bridge structure..., Louisiana. The deviation is necessary to perform electrical rehabilitation work on the bridge. This...

  8. 77 FR 28767 - Drawbridge Operation Regulation; Hood Canal, WA

    Science.gov (United States)

    2012-05-16

    ... hour road traffic on State Routes 3 and 104 by allowing the draw of the bridge to remain closed to... rush hour road traffic by reducing bridge openings, thereby reducing traffic queues and delays due to... Bridge be changed to provide some relief to road traffic on State Routes 3 and 104. Traffic queues south...

  9. 75 FR 32275 - Regulated Navigation Area; Gulf Intracoastal Waterway, Inner Harbor Navigation Canal, Harvey...

    Science.gov (United States)

    2010-06-08

    ..., Inner Harbor Navigation Canal, Harvey Canal, Algiers Canal, New Orleans, LA AGENCY: Coast Guard, DHS...), Harvey Canal, and Algiers Canal during severe hurricane conditions. Vessels will not be permitted to stay... communities within the IHNC, Harvey, and Algiers Canals from potential hazards associated with vessels being...

  10. 21 CFR 872.3820 - Root canal filling resin.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Root canal filling resin. 872.3820 Section 872...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3820 Root canal filling resin. (a) Identification. A root canal filling resin is a device composed of material, such as methylmethacrylate, intended...

  11. 5 CFR 550.714 - Panama Canal Commission employees.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Panama Canal Commission employees. 550... PAY ADMINISTRATION (GENERAL) Severance Pay § 550.714 Panama Canal Commission employees. (a) Notwithstanding any other provisions of this subpart, an employee separated from employment with the Panama Canal...

  12. Maxillary First Premolar with Three Root Canals: A Case Report ...

    African Journals Online (AJOL)

    ... the tooth is needed to ensure a proper endodontic treatment. This article reports a rare finding of three canals in a maxillary first premolar with non well defined root outline radiographically during an elective root canal treatment. Keywords: Maxillary First Premolar, Endodontic Treatment, Elective, Root Canal Morphology ...

  13. Lumbar Vertebral Canal Diameters in Adult Ugandan Skeletons ...

    African Journals Online (AJOL)

    Background: Normal values of lumbar vertebral canal diameters are useful in facilitating diagnosis of lumbar vertebral canal stenosis. Various studies have established variation on values between different populations, gender, age, and ethnic groups. Objectives: To determine the lumbar vertebral canal diameters in adult ...

  14. Mode-locking via dissipative Faraday instability.

    Science.gov (United States)

    Tarasov, Nikita; Perego, Auro M; Churkin, Dmitry V; Staliunas, Kestutis; Turitsyn, Sergei K

    2016-08-09

    Emergence of coherent structures and patterns at the nonlinear stage of modulation instability of a uniform state is an inherent feature of many biological, physical and engineering systems. There are several well-studied classical modulation instabilities, such as Benjamin-Feir, Turing and Faraday instability, which play a critical role in the self-organization of energy and matter in non-equilibrium physical, chemical and biological systems. Here we experimentally demonstrate the dissipative Faraday instability induced by spatially periodic zig-zag modulation of a dissipative parameter of the system-spectrally dependent losses-achieving generation of temporal patterns and high-harmonic mode-locking in a fibre laser. We demonstrate features of this instability that distinguish it from both the Benjamin-Feir and the purely dispersive Faraday instability. Our results open the possibilities for new designs of mode-locked lasers and can be extended to other fields of physics and engineering.

  15. Use of versapoint to refashion the cervical canal to overcome unusually difficult embryo transfers and improve in-vitro fertilization-embryo transfer outcome: A case series

    Directory of Open Access Journals (Sweden)

    Nalini Mahajan

    2011-01-01

    Full Text Available Background : Smooth atraumatic embryo transfer is paramount for the success of in-vitro fertilization (IVF. In difficult cases, cervical canal manipulation may be required. Aim : To see if surgical correction of the cervical canal or cervical canal refashioning could improve ease of embryo transfer. Setting : Private infertility and IVF hospital. Design : Prospective study. Materials and Methods : Patients: 11 women with failed 1-3 IVF cycles with history of extremely difficult embryo transfers (ETs despite undergoing cervical dilatation in the cycle prior to IVF. Interventions : Operative hysteroscopy using Versapoint for refashioning of the cervical canal. Main Outcome Measures : Ease of ET in the subsequent IVF cycle. Secondary outcome measure was to assess reproductive outcome. Results : Easy and atraumatic ET in the IVF cycle after procedure in 100% patients. PR was 46.5%. Conclusions : Use of Versapoint for refashioning the cervical canal can improve the quality of ET and PR.

  16. John Locke and the case of Anthony Ashley Cooper.

    Science.gov (United States)

    Anstey, Peter R; Principe, Lawrence M

    2011-01-01

    In June 1668 Anthony Ashley Cooper, later to become the 1st Earl of Shaftesbury, underwent abdominal surgery to drain a large abscess above his liver. The case is extraordinary, not simply on account of the eminence of the patient and the danger of the procedure, but also because of the many celebrated figures involved. A trove of manuscripts relating to this famous operation survives amongst the Shaftesbury Papers in the National Archives at Kew. These include case notes in the hand of the philosopher John Locke and advice from leading physicians of the day including Francis Glisson, Sir George Ent and Thomas Sydenham. The majority of this material has never been published before. This article provides complete transcriptions and translations of all of these manuscripts, thus providing for the first time a comprehensive case history. It is prefaced with an extended introduction.

  17. The crazy project – Canal Istanbul

    Directory of Open Access Journals (Sweden)

    Seda Kundak

    2011-10-01

    Full Text Available It was late April 2011 when “the Crazy Project - Canal Istanbul” was proposed by the Prime Minister of Turkey, during his election campaign.  Although the idea of an artificial canal is not new, since it is initiated without any consensus between the people and institutions in Istanbul, the project immediately set a large number of debates. These vary from the legitimacy of decentralization of governance, to potential impacts of the canal on international politics, economy, environment and urban life.  Regarding past infrastructure projects in Istanbul, such large scale investments have caused extensive acceleration in construction sector in one hand and social and economic shifts on the other.  In this paper, the Canal Istanbul Project is evaluated according to basic motivations and claims of the PM, multi-perspective view through challenges and limitation that the project is likely to face with and speculations on implementation approach. The final discussion on the project is based on benefits/losses of Istanbul once the project will be implemented.

  18. Cancer of the external auditory canal

    DEFF Research Database (Denmark)

    Nyrop, Mette; Grøntved, Aksel

    2002-01-01

    OBJECTIVE: To evaluate the outcome of surgery for cancer of the external auditory canal and relate this to the Pittsburgh staging system used both on squamous cell carcinoma and non-squamous cell carcinoma. DESIGN: Retrospective case series of all patients who had surgery between 1979 and 2000. M...

  19. Infrared typmanic tempature and ear canal morphology

    NARCIS (Netherlands)

    Daanen, H.A.M.

    2006-01-01

    Several publications indicate that the infrared tympanic temperature (IRTT) underestimates the core temperature of the body when the ear canal is long, curvy and narrow. In order to quantify these observations, a study was performed in 10 subjects. The IRTT was determined and compared to the

  20. The Panama Canal and Social Justice.

    Science.gov (United States)

    Wilde, Margaret D., Ed.

    The booklet, designed to explore the issues of international justice in the context of the Gospel, reviews relations between the United States and Panama. It includes background materials and a study guide for parish leaders and other educators. The central question pertaining to the Panama Canal concerns the rights of the United States according…

  1. Residuos de antimicrobianos en canales de vacas

    National Research Council Canada - National Science Library

    GESCHE, E; EMILFORK, C

    1998-01-01

    Con la finalidad de conocer la presencia de residuos de antibióticos y sulfamidas en animales de abasto, se analizaron las canales de 300 vacas faenadas en una Planta Faenadora de Carnes de la X Región de Chile...

  2. Management of a locked Strata valve.

    Science.gov (United States)

    Bullivant, Kelly J; Mitha, Alim P; Hamilton, Mark G

    2009-04-01

    The PS Medical Strata valve is a programmable shunt valve used in the treatment of hydrocephalus that allows for noninvasive changes in the pressure setting using a magnet. The Strata valve is sensitive to magnetic fields, and reprogramming is frequently necessary after MR imaging. A known but rare complication of the Strata valve is that the rotor can become locked, causing shunt malfunction. This complication can only occur in a first generation Strata valve.

  3. Dither Cavity Length Controller with Iodine Locking

    Directory of Open Access Journals (Sweden)

    Lawson Marty

    2016-01-01

    Full Text Available A cavity length controller for a seeded Q-switched frequency doubled Nd:YAG laser is constructed. The cavity length controller uses a piezo-mirror dither voltage to find the optimum length for the seeded cavity. The piezo-mirror dither also dithers the optical frequency of the output pulse. [1]. This dither in optical frequency is then used to lock to an Iodine absorption line.

  4. Locke and the education of the adolescent

    OpenAIRE

    Francisco T. Baciero Ruiz

    2008-01-01

    John Locke has been considered one of the leading figures in the His- tory of Philosophy, specially for his two famous treatises An Essay concerning Human understanding and Two Treatises on Government. None the less his work in Pedagogy, Some thougths concerning Education, is no less important, and provides the leading strings of that what ought to be the education of the gentleman, whose unavoidable foundation must be a solid education in virtue grounded in the moral principles of Christiani...

  5. Semiconductor laser irradiation improves root canal sealing during routine root canal therapy

    OpenAIRE

    Su, Dandan; Hu, Xingxue; Wang, Dashan; Cui, Ting; Yao, RuYong; Sun, Huibin

    2017-01-01

    Objective To evaluate the effect of semiconductor laser irradiation on root canal sealing after routine root canal therapy (RCT). Methods Sixty freshly extracted single-rooted human teeth were randomly divided into six groups (n = 10). The anatomic crowns were sectioned at the cementoenamel junction and the remaining roots were prepared endodontically with conventional RCT methods. Groups A and B were irradiated with semiconductor laser at 1W for 20 seconds; Groups C and D were ultrasonically...

  6. Laser Metrology Heterodyne Phase-Locked Loop

    Science.gov (United States)

    Loya, Frank; Halverson, Peter

    2009-01-01

    A method reduces sensitivity to noise in a signal from a laser heterodyne interferometer. The phase-locked loop (PLL) removes glitches that occur in a zero-crossing detector s output [that can happen if the signal-to-noise ratio (SNR) of the heterodyne signal is low] by the use of an internal oscillator that produces a square-wave signal at a frequency that is inherently close to the heterodyne frequency. It also contains phase-locking circuits that lock the phase of the oscillator to the output of the zero-crossing detector. Because the PLL output is an oscillator signal, it is glitch-free. This enables the ability to make accurate phase measurements in spite of low SNR, creates an immunity to phase error caused by shifts in the heterodyne frequency (i.e. if the target moves causing Doppler shift), and maintains a valid phase even when the signal drops out for brief periods of time, such as when the laser is blocked by a stray object.

  7. [Tibiotalocalcaneal arthrodesis using a humeral locking plate].

    Science.gov (United States)

    Cabrera Méndez, M P; Gamba, C; Hernández, E; Molano, J; Andrade, J C

    2016-01-01

    To describe the results of tibiotalocalcáneal arthrodesis (TTC) using a humeral locking plate. A retrospective, observational study was conducted between January 2007 and December 2013 in the Hospital Militar Central de Bogotá. The study included patients with symptomatic osteoarthritis diagnosed clinically and radiologically, and who underwent TTC arthrodesis using a humeral locking plate with a minimum follow up of 6 months. The total number patients was 35, of whom 7 (20%) were women and 28 (80%) men, with a mean age 36.3 years (19.77). 74% with post-traumatic arthritis, most of them secondary to gunshot wounds and fragmentation weapons, and neuropathic in 20%. An autogenous graft was used in 13 cases, and 14 cases using both, with a mean consolidation time of 4.37 months. Complications include, delayed union in 3 cases, and surgical site infection in 4. The postoperative functionality (AOFAS) mean was 66.7/100 points, with a score of 2.35 on a visual analogue pain scale. TTC arthrodesis using a humeral locking plate is a suitable option for fixing this type of arthrodesis, with a low rate of complications, and postoperative results that revealed satisfactory improvement in pain and consolidation. Copyright © 2015 SECOT. Published by Elsevier Espana. All rights reserved.

  8. 75 FR 78234 - Lock+TM

    Science.gov (United States)

    2010-12-15

    ... project (Project No. 13780-000) would consist of: (1) An 85-foot-long, 100-foot-wide, 14-foot-deep excavated power canal; (2) a 95-foot-long, 100-foot-wide, 10-foot-deep excavated tailrace; (3) a 100-foot...)(iii) and the instructions on the Commission's Web site http://www.ferc.gov/docs-filing/efiling.asp...

  9. 75 FR 78236 - Lock+TM

    Science.gov (United States)

    2010-12-15

    ...: (1) A 75-foot-long, 65-foot-wide, 20-foot-deep excavated power canal; (2) a 55-foot-long, 65-foot-wide, 8-foot-deep excavated tailrace; (3) a 45-foot-long, 110-foot-wide, 40-foot-high concrete... electronically via the Internet. See 18 CFR 385.2001(a)(1)(iii) and the instructions on the Commission's Web site...

  10. First clinical results of the Locking Compression Plate (LCP).

    Science.gov (United States)

    Sommer, Christoph; Gautier, Emanuel; Müller, Matthias; Helfet, David L; Wagner, Michael

    2003-11-01

    The Locking Compression Plate (LCP) is a new screw-plate system that offers the possibility of inserting conventional and locking head screws into the specially designed combination holes. It represents a further development of the PC-Fix and the LISS and was released for clinical application in March 2000. In a prospective multicentre study, the new system was used to treat 144 patients (f: 67, m: 77; average age: 51.4 years) with 169 fractures: of these, 57 were tibial fractures, 45 humerus, 19 radius and 18 femoral. After one year, clinical and radiological follow-up assessment was carried out on 127 patients with 151 fractures (88%). In 130 fractures (86%), healing took place within the expected period and without complication or secondary dislocation ("uneventful healing"). In 19 patients, a total of 27 unexpected complications occurred ("adverse events"), in which 18 revision operations were necessary in 13 patients: five for implant loosening/pull-out, four for plate failure, one for non-union, five for secondary fractures immediately adjacent to the implant after a subsequent injury and two for infection. Analysis by a committee of experts indicated that mechanical complications arose entirely from technical errors of application (incorrect fixation technique, incorrect choice of plate). No purely implant-related complications were observed. The new system can be regarded as technically mature. It offers numerous fixation possibilities and has proven its worth in complex fractures situations and in revision operations after the failure of other implants. A good knowledge of biomechanics is essential as well as precise preoperative planning.

  11. MR determination of neonatal spinal canal depth

    Energy Technology Data Exchange (ETDEWEB)

    Arthurs, Owen, E-mail: owenarthurs@uk2.net [Centre for Cardiovascular MR, Great Ormond Street Hospital for Children, London WC1N 3JH (United Kingdom); Thayyil, Sudhin, E-mail: s.thayyil@ucl.ac.uk [Academic Neonatology, Institute for Women' s Health, London WC1E 6AU (United Kingdom); Wade, Angie, E-mail: a.wade@ucl.ac.uk [Centre for Paediatric Epidemiology and Biostatistics, UCL Institute of Child Health, London (United Kingdom); Chong, W.K., E-mail: Kling.Chong@gosh.nhs.uk [Paediatric Neuroradiology, Great Ormond Street Hospital for Children, London (United Kingdom); Sebire, Neil J., E-mail: Neil.Sebire@gosh.nhs.uk [Histopathology, Great Ormond Street Hospital for Children, London WC1E 6AU (United Kingdom); Taylor, Andrew M., E-mail: a.taylor76@ucl.ac.uk [Centre for Cardiovascular MR, Cardiorespiratory Unit, Great Ormond Street Hospital for Children and UCL Institute of Cardiovascular Science, London WC1E 6AU (United Kingdom)

    2012-08-15

    Objectives: Lumbar punctures (LPs) are frequently performed in neonates and often result in traumatic haemorrhagic taps. Knowledge of the distance from the skin to the middle of the spinal canal (mid-spinal canal depth - MSCD) may reduce the incidence of traumatic taps, but there is little data in extremely premature or low birth weight neonates. Here, we determined the spinal canal depth at post-mortem in perinatal deaths using magnetic resonance imaging (MRI). Patients and methods: Spinal canal depth was measured in 78 post-mortem foetuses and perinatal cases (mean gestation 26 weeks; mean weight 1.04 kg) at the L3/L4 inter-vertebral space at post-mortem MRI. Both anterior (ASCD) and posterior (PSCD) spinal canal depth were measured; MSCD was calculated and modelled against weight and gestational age. Results: ASCD and PSCD (mm) correlated significantly with weight and gestational age (all r > 0.8). A simple linear model MSCD (mm) = 3 Multiplication-Sign Weight (kg) + 5 was the best fit, identifying an SCD value within the correct range for 87.2% (68/78) (95% CI (78.0, 92.9%)) cases. Gestational age did not add significantly to the predictive value of the model. Conclusion: There is a significant correlation between MSCD and body weight at post-mortem MRI in foetuses and perinatal deaths. If this association holds in preterm neonates, use of the formula MSCD (mm) = 3 Multiplication-Sign Weight (kg) + 5 could result in fewer traumatic LPs in this population.

  12. Cervical spinal canal narrowing in idiopathic syringomyelia

    Energy Technology Data Exchange (ETDEWEB)

    Struck, Aaron F. [Massachusetts General Hospital, Department of Neurology, Boston, MA (United States); Carr, Carrie M. [Mayo Clinic, Department of Radiology, Rochester, MN (United States); Shah, Vinil [University of California San Francisco, Department of Radiology, San Francisco, CA (United States); Hesselink, John R. [University of California San Diego, Department of Radiology, San Diego, CA (United States); Haughton, Victor M. [University of Wisconsin, Department of Radiology, Madison, WI (United States)

    2016-08-15

    The cervical spine in Chiari I patient with syringomyelia has significantly different anteroposterior diameters than it does in Chiari I patients without syringomyelia. We tested the hypothesis that patients with idiopathic syringomyelia (IS) also have abnormal cervical spinal canal diameters. The finding in both groups may relate to the pathogenesis of syringomyelia. Local institutional review boards approved this retrospective study. Patients with IS were compared to age-matched controls with normal sagittal spine MR. All subjects had T1-weighted spin-echo (500/20) and T2-weighted fast spin-echo (2000/90) sagittal cervical spine images at 1.5 T. Readers blinded to demographic data and study hypothesis measured anteroposterior diameters at each cervical level. The spinal canal diameters were compared with a Mann-Whitney U test. The overall difference was assessed with a Friedman test. Seventeen subjects were read by two reviewers to assess inter-rater reliability. Fifty IS patients with 50 age-matched controls were studied. IS subjects had one or more syrinxes varying from 1 to 19 spinal segments. Spinal canal diameters narrowed from C1 to C3 and then enlarged from C5 to C7 in both groups. Diameters from C2 to C4 were narrower in the IS group (p < 0.005) than in controls. The ratio of the C3 to the C7 diameters was also smaller (p = 0.004) in IS than controls. Collectively, the spinal canal diameters in the IS were significantly different from controls (Friedman test p < 0.0001). Patients with IS have abnormally narrow upper and mid cervical spinal canal diameters and greater positive tapering between C3 and C7. (orig.)

  13. Cervical spinal canal narrowing in idiopathic syringomyelia.

    Science.gov (United States)

    Struck, Aaron F; Carr, Carrie M; Shah, Vinil; Hesselink, John R; Haughton, Victor M

    2016-08-01

    The cervical spine in Chiari I patient with syringomyelia has significantly different anteroposterior diameters than it does in Chiari I patients without syringomyelia. We tested the hypothesis that patients with idiopathic syringomyelia (IS) also have abnormal cervical spinal canal diameters. The finding in both groups may relate to the pathogenesis of syringomyelia. Local institutional review boards approved this retrospective study. Patients with IS were compared to age-matched controls with normal sagittal spine MR. All subjects had T1-weighted spin-echo (500/20) and T2-weighted fast spin-echo (2000/90) sagittal cervical spine images at 1.5 T. Readers blinded to demographic data and study hypothesis measured anteroposterior diameters at each cervical level. The spinal canal diameters were compared with a Mann-Whitney U test. The overall difference was assessed with a Friedman test. Seventeen subjects were read by two reviewers to assess inter-rater reliability. Fifty IS patients with 50 age-matched controls were studied. IS subjects had one or more syrinxes varying from 1 to 19 spinal segments. Spinal canal diameters narrowed from C1 to C3 and then enlarged from C5 to C7 in both groups. Diameters from C2 to C4 were narrower in the IS group (p < 0.005) than in controls. The ratio of the C3 to the C7 diameters was also smaller (p = 0.004) in IS than controls. Collectively, the spinal canal diameters in the IS were significantly different from controls (Friedman test p < 0.0001). Patients with IS have abnormally narrow upper and mid cervical spinal canal diameters and greater positive tapering between C3 and C7.

  14. Comparison of different retreatment techniques and root canal sealers: a scanning electron microscopic study

    Directory of Open Access Journals (Sweden)

    Neslihan Simsek

    2014-05-01

    Full Text Available The aim of this study was to evaluate the effectiveness of two retreatment techniques, in terms of the operating time and scanning electron microscopy (SEM results, in removing three different root canal sealers from root canals that were previously filled with gutta-percha. Sixty extracted single-rooted human premolars were divided into three groups and filled with iRoot SP, MM Seal, and AH Plus sealers, along with gutta-percha, through a lateral compaction technique. Root canal fillings of the samples were removed by ESI ultrasonic tips or R-Endo files. The time to reach the working length was recorded. Longitudinally sectioned samples were examined under SEM magnification. Each picture was evaluated in terms of the residual debris. Data were statistically analyzed with the Kruskall-Wallis test. No statistically significant differences were found in terms of operating time (p>0.05. Significant differences in the number of debris-free dentinal tubules were found among the root canal thirds, but this finding was not influenced by the experimental group (p < 0.05. Resin sealer tags were observed inside the dentinal tubules in the MM Seal group. Under the conditions of this study, it may be established that there was no difference among the sealers and retreatment techniques.

  15. A novel injection-locked amplitude-modulated magnetron at 1497 MHz

    Energy Technology Data Exchange (ETDEWEB)

    Neubauer, Michael [Muons Inc., Batavia, IL (United States); Wang, Haipeng [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2015-12-15

    Thomas Jefferson National Accelerator Facility (JLab) uses low efficiency klystrons in the CEBAF machine. In the older portion they operate at 30% efficiency with a tube mean time between failure (MTBF) of five to six years. A highly efficient source (>55-60%) must provide a high degree of backwards compatibility, both in size and voltage requirements, to replace the klystron presently used at JLab, while providing energy savings. Muons, Inc. is developing a highly reliable, highly efficient RF source based upon a novel injection-locked amplitude modulated (AM) magnetron with a lower total cost of ownership, >80% efficiency, and MTBF of six to seven years. The design of the RF source is based upon a single injection-locked magnetron system at 8 kW capable of operating up to 13 kW, using the magnetron magnetic field to achieve the AM required for backwards compatibility to compensate for microphonics and beam loads. A novel injection-locked 1497 MHz 8 kW AM magnetron with a trim magnetic coil was designed and its operation numerically simulated during the Phase I project. The low-level RF system to control the trim field and magnetron anode voltage was designed and modeled for operation at the modulation frequencies of the microphonics. A plan for constructing a prototype magnetron and control system was developed.

  16. Root canal shaping using rotary nickel-titanium files in preclinical dental education in Turkey.

    Science.gov (United States)

    Ünal, Gül Çelik; Maden, Murat; Orhan, Ekim Onur; Sarıtekin, Erdal; Teke, Anıl

    2012-04-01

    The purposes of this study were to evaluate the ability of a group of third-year dental students without any endodontic clinical experience to use the ProTaper Instruments (Dentsply Maillefer) to decrease the amount of straightening of curved canals on human molar teeth and to determine the incidence of instrument fractures and instrumentation time. Thirty-one undergraduate dental students in Turkey received a training session. The students prepared a total of 144 root canals in human mandibular or maxillary molar teeth with ProTaper. Fifty-six teeth were excluded due to unreadable image, misinformation, or straight or severe curve. Using pre- and post-preparation digital radiographs, the straightening of curved root canals was investigated. Loss of working length and incidence of fracture were also noted. A total of eighty-eight curved root canals were selected. Mesiobuccal or mesiolingual roots with curvatures of between 20° and 43° as assessed by Schneider's method and working length of between 15 mm and 22.5 mm were included in the study. The means of the curved root canals before and after the instrumentation were 29.5° ± 6° and 27° ± 6.3°, respectively. The means of the working length before and after the instrumentation were 19 mm ± 2.1 mm and 18.3 mm ± 1.9 mm, respectively. A statistically significant difference between straightening of curved root canals and loss of working length was found between before and after instrumentation (plength after preparation with the size F1 ProTaper file were 2.5 mm ± 3.6 mm and 0.7 mm ± 0.6 mm, respectively. Only two F1 ProTaper instruments fractured at the apical level. The study concluded that rotary instruments performed adequately with inexperienced operators who received a brief structured training session.

  17. Sub-wavelength resolution dynamics of semiconductor passively mode-locked lasers induced by optical feedback

    Science.gov (United States)

    Simos, Christos; Simos, Hercules; Syvridis, Dimitris

    2017-08-01

    We present a numerical analysis that focuses, for the first time to our knowledge, on the feedback-induced dynamics in a semiconductor passively mode-locked laser with sub-wavelength resolution. Our results and the corresponding theoretical explanations elucidate several aspects of the laser dynamics under self-injection including inherent properties of mode-locked lasers such as pulse intensity noise and timing jitter. We show that the dynamics of the laser exhibit a periodicity in the wavelength scale apparent only on integer multiples of the laser cavity and decays in the time scale of the pulse duration following the coherence of the mode-locked laser. The corresponding phenomena are dominant for external cavities that are shorter than the laser cavity and superimposed on the previously reported dynamics of the semiconductor mode-locked lasers for longer external delays. Since these dynamics are triggered by low feedback levels, our study could be useful for the optimization of the laser operation in cases where ultra-short external cavity lengths are involved (integrated designs, power collection with fiber tapers, etc.).

  18. Graphene mode-locked femtosecond Cr2+:ZnS laser with ~300 nm tuning range.

    Science.gov (United States)

    Cho, Won Bae; Choi, Sun Young; Zhu, Chunhui; Kim, Mi Hye; Kim, Jun Wan; Kim, Jin Sun; Park, Hyung Ju; Shin, Dong Ho; Jung, Moon Youn; Wang, Fengqiu; Rotermund, Fabian

    2016-09-05

    Graphene has proved to be an excellent broadband saturable absorber for mode-locked operation of ultrafast lasers. However, for the mid-infrared (mid-IR) range where broadly tunable sources are in great needs, graphene-based broadly tunable ultrafast mid-IR lasers have not been demonstrated so far. Here, we report on passive mode-locking of a mid-IR Cr:ZnS laser by utilizing a transmission-type monolayer graphene saturable absorber and broad spectral tunability between 2120 nm and 2408 nm, which is the broadest tuning bandwidth ever reported for graphene mode-locked mid-IR solid-state lasers. The recovery time of the saturable absorber is measured to be ~2.4 ps by pump-probe technique at a wavelength of 2350 nm. Stably mode-locked Cr:ZnS laser delivers Fourier transform-limited 220-fs pulses with a pulse energy of up to 7.8 nJ.

  19. Can silicon carbide serve as a saturable absorber for passive mode-locked fiber lasers?

    Science.gov (United States)

    Cheng, Chih-Hsien; Lin, Yung-Hsiang; Chen, Ting-Hui; Chen, Hsiang-Yu; Chi, Yu-Chieh; Lee, Chao-Kuei; Leeb, Chao-Kuei; Wu, Chih-I; Wua, Chih-I; Lin, Gong-Ru

    2015-11-12

    The study presents a novel demonstration of a passively mode-locked erbium-doped fiber laser (EDFL) that is based on a silicon carbide (SixC1-x) saturable absorber. When the C/Si composition ratio is increased to 1.83, the SixC1-x film transforms from two-photon absorption to nonlinear saturable absorption, and the corresponding value reaches -3.9 × 10(-6) cm/W. The Si-rich SixC1-x film cannot mode lock the EDFL because it induced high intracavity loss through two-photon absorption. Even when a stoichiometric SiC is used, the EDFL is mode locked, similar to an EDFL operating under weak nonlinear-polarization-rotation condition. A C-rich SixC1-x film containing sp(2)-orbital C-C bonds with a linear absorbance of 0.172 and nonlinear absorbance of 0.04 at a 181 MW/cm(2) saturation intensity demonstrates nonlinear transmittance. The C-rich SixC1-x saturable absorber successfully generates a short mode-locked EDFL pulse of 470 fs. The fluctuation of the pulse-train envelope dropps considerably from 11.6% to 0.8% when a strong saturable-absorption-induced self-amplitude modulation process occurs in the C-rich SixC1-x film.

  20. Quality of life after cholesteatoma surgery: intact-canal wall tympanoplasty versus canal wall-down tympanoplasty with mastoid obliteration.

    Science.gov (United States)

    Quaranta, Nicola; Iannuzzi, Lucia; Petrone, Paolo; D'Elia, Alessandra; Quaranta, Antonio

    2014-02-01

    The aim of this study was to evaluate, by means of the Chronic Ear Survey (CES), the quality of life of patients who had undergone either intact-canal wall tympanoplasty (ICWT) or canal wall-down tympanoplasty (CWDT) with mastoid obliteration. This was a retrospective case review study performed at a tertiary referral center. Among 379 patients affected by middle ear and mastoid cholesteatoma operated on between November 2000 and December 2009, 50 patients who underwent ICWT and 50 who underwent CWDT with mastoid obliteration were randomly selected. The CES scores were analyzed for both groups. The mean scores on the CES were 6.5 ± 2.1 in patients who underwent CWDT and 6.9 ± 2.2 in patients treated with ICWT (t = -0.93; p > 0.05). No significant differences between the two groups were found on the activity restriction, symptom, or medical resource subscales (p > 0.05). The results of this study demonstrate that CWDT with mastoid obliteration resulted in a quality of life comparable with that after ICWT. Postoperative hearing loss is the most frequently reported problem for both techniques.

  1. A prospective cohort study of endodontic treatments of 1,369 root canals: results after 5 years.

    Science.gov (United States)

    Ricucci, Domenico; Russo, John; Rutberg, Michael; Burleson, Josef A; Spångberg, Larz S W

    2011-12-01

    The purpose of this prospective study was: 1) to follow-up a large number of endodontic treatments performed by a single operator, periodically checked over a 5-year period; and 2) to correlate outcome to a number of clinical variables. This prospective study included all consecutive cases during the selected time period. All cases were followed regularly for a 5-year period. At the 5-year end point of the study, 470 patients with 816 treated teeth and with 1,369 treated root canals were available for evaluation. The overall rate of success among the 816 teeth/1,369 root canals available for evaluation was 88.6%/90.3%. The success rate for 435 teeth/793 root canals undergoing vital pulp therapy was 91.5%/93.1%. Teeth/root canals with necrotic pulp but without detectable periapical bone lesion were successfully treated in 89.5%/92.3%. If the pulp necrosis was complicated by apical periodontitis, the success rate fell to 82.7% for the teeth and 84.1% for the root canals (P = .037). Teeth with periapical lesion length was identified. Excess of root canal filling material decreases success. Infected pulp space should be treated with an effective intracanal dressing. The quality of the coronal restoration or the placement of intracanal post retentions does not affect treatment outcome. Copyright © 2011 Mosby, Inc. All rights reserved.

  2. Diode-pumped mode-locked Tm:LuAG laser at 2  μm based on GaSb-SESAM.

    Science.gov (United States)

    Luan, C; Yang, K; Zhao, J; Zhao, S; Li, T; Zhang, H; He, J; Song, L; Dekorsy, T; Guina, M; Zheng, L

    2017-02-15

    Mode-locking of a directly diode-pumped Tm:LuAG laser is demonstrated using GaSb-based semiconductor saturable absorber mirrors (SESAMs). Stable and self-starting mode-locked operation was realized, generating pulses as short as 13.6 ps at 2024 nm with a maximum output power of 98 mW. Two GaInAs-based SESAMs were used for comparison with the operation based upon the use of the GaSb SESAM; in this case, longer pulses with durations of 27 ps and 34 ps were obtained under the same experimental conditions. Our work sets a new record in pulse duration for mode-locked Tm:LuAG lasers and confirms that lattice-matched GaSb-based SESAMs are beneficial for mode-locked solid-state lasers in the 2 μm range.

  3. A new system for classifying tooth, root and canal anomalies.

    Science.gov (United States)

    Ahmed, H M A; Dummer, P M H

    2017-10-12

    Understanding the normal anatomical features as well as the more unusual developmental anomalies of teeth, roots and root canals is essential for successful root canal treatment. In addition to various types of root canal configuration and accessory canal morphology, a wide range of developmental tooth, root and canal anomalies exists, including C-shaped canals, dens invaginatus, taurodontism, root fusion, dilacerations and palato-gingival grooves. There is a direct association between developmental anomalies and pulp and periradicular diseases that usually require a multidisciplinary treatment approach to achieve a successful outcome. A number of classifications have categorized tooth, root and canal anomalies; however, several important details are often missed making the classifications less than ideal and potentially confusing. Recently, a new coding system for classifying root, root canal and accessory canal morphology has been introduced. The purpose of this article is to introduce a new system for classifying tooth, root and canal anomalies for use in research, clinical practice and training, which can serve as complementary codes to the recently described system for classifying root, as well as main and accessory canal morphology. © 2017 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  4. [Measurements of semicircular canal space direction with MRI].

    Science.gov (United States)

    Yang, Xiaokai; Wu, Shuzhi; Ye, Hua

    2015-10-01

    Measure the space direction of semicircular canals to provide the anatomical basis for the diagnosis and treatment of BPPV. We calculated angles among semicircular canals of 24 patients using MRI scaning with 3D-CISS sequence. The angle between the left and right posterior semicircular canals was 106.61 degress ± 8.58 degrees, so the angle among the posterior semicircular canals and sagittal head plane was 53.31 degrees ± 4.29 degrees. Pairs of contralateral synergistic canal planes were not parallel, forming 171.67 degrees ± 4.36 degrees between the left and right horizontal semicircular canal planes, 154.37 degrees ± 10.87 degrees between the left posterior and right anterior semicircular canal planes and 156.84 degrees ± 9.34 degrees between the right posterior and left anterior semicircular canal planes. Our measurement of the angles among semicircular canals coincided with those of previous reports. The angles between contralateral synergistic canal planes were close to parallel, but the angle between the posterior semicircular canals and sagittal head plane was great than 45 degrees that traditionally thought to be.

  5. Evaluation of an ultrasonic technique to remove fractured rotary nickel-titanium endodontic instruments from root canals: clinical cases.

    Science.gov (United States)

    Ward, Jeff R; Parashos, Peter; Messer, Harold H

    2003-11-01

    The removal of fractured rotary nickel-titanium instruments from small, curved root canals is one of the most complex operative procedures in endodontics. There have been many different devices and techniques developed to remove fractured instruments, but none are consistently successful and all show a high incidence of canal damage such as perforation. A technique using a staging platform and the use of modern ultrasonic tips with direct visualization through a dental operating microscope has recently been evaluated. The use of this technique in clinical practice is described in 24 cases and illustrated by 3 cases.

  6. Report on first masing and single mode locking in a prebunched beam FEM oscillator

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, M.; Eichenbaum, A.; Kleinman, H. [Tel-Aviv Univ., Ramat-Aviv (Israel)] [and others

    1995-12-31

    Radiation characteristics of a table-top free electron maser (FEM) are described in this paper. The FEM employs a prebunched electron beam and is operated as an oscillator in the low-gain collective (Raman) regime. Using electron beam prebunching single mode locking at any one of the possible oscillation modes was obtained. The electron beam is prebunched by a microwave tube section before it is injected into the wiggler. By tuning the electron beam bunching frequency, the FEM oscillation frequency can be locked to any eigen frequency of the resonant waveguide cavity which is within the frequency band of net gain of the FEM. The oscillation build up process is sped up, when the FEM operates with a prebunched electron beam, and the build-up time of radiation is shortened significantly. First measurements of masing with and without prebunching and characterization of the emitted radiation are reported.

  7. Development of LabVIEW Program for Lock-In Infrared Thermography

    Energy Technology Data Exchange (ETDEWEB)

    Min, Tae Hoon; Na, Hyung Chul; Kim, Noh Yu [Chonnam National University, Gwangju (Korea, Republic of)

    2011-04-15

    A LabVIEW program has been developed together with simple infrared thermography(IRT) system to control the lock-in conditions of the system efficiently. The IR imaging software was designed to operate both of infrared camera and halogen lamp by synchronizing them with periodic sine signal based on thyristor(SCR) circuits. LabVIEW software was programmed to provide users with screen-menu functions by which it can change the period and energy of heat source, operate the camera to acquire image, and monitor the state of the system on the computer screen In experiment, lock-in IR image for a specimen with artificial hole defects was obtained by the developed IRT system and compared with optical image

  8. Multi-wavelength, all-solid-state, continuous wave mode locked picosecond Raman laser.

    Science.gov (United States)

    Granados, Eduardo; Pask, Helen M; Esposito, Elric; McConnell, Gail; Spence, David J

    2010-03-01

    We demonstrate the operation of a cascaded continuous wave (CW) mode-locked Raman oscillator. The output pulses were compressed from 28 ps at 532 nm down to 6.5 ps at 559 nm (first Stokes) and 5.5 ps at 589 nm (second Stokes). The maximum output was 2.5 W at 559 nm and 1.4 W at 589 nm with slope efficiencies up to 52%. This technique allows simple and efficient generation of short-pulse radiation to the cascaded Stokes wavelengths, extending the mode-locked operation of Raman lasers to a wider range of visible wavelengths between 500 - 650 nm based on standard inexpensive picosecond Nd:YAG oscillators.

  9. Kerr-lens mode-locked femtosecond Cr(2+):ZnSe laser at 2420 nm.

    Science.gov (United States)

    Cizmeciyan, M Natali; Cankaya, Huseyin; Kurt, Adnan; Sennaroglu, Alphan

    2009-10-15

    We describe a cw Kerr-lens mode-locked Cr(2+):ZnSe laser pumped by a 1800 nm thulium fiber laser. The astigmatically compensated asymmetric x cavity contained a 2.4-mm-long Cr(2+):ZnSe sample with a pump absorption coefficient of 11.6 cm(-1) and was operated with a 1% output coupler. The dispersion compensation was achieved by using a MgF(2) prism pair. During Kerr-lens mode-locked operation, we could generate 95 fs pulses at a pulse repetition rate of 94.3 MHz and with 40 mW of output power. The center wavelength of the pulses was 2420 nm. The pulses had a spectral width of 69 nm and a time-bandwidth product of 0.335, which is close to the transform limit for hyperbolic secant pulses.

  10. Optimization of the phase-locked flux-flow oscillator for the submm integrated receiver

    DEFF Research Database (Denmark)

    Koshelets, V. P.; Dmitriev, P. M.; Ermakov, A. B.

    2005-01-01

    The Superconducting Integrated Receiver (SIR) comprises in one chip a planar antenna integrated with an SIS mixer, a superconducting Flux Flow Oscillator (FFO) acting as Local Oscillator (LO) and a second SIS harmonic mixer (HM) for FFO phase locking. Free-running FFO linewidth well below 10 MHz...... is required to ensure phase-locked operation of an SIR. Comprehensive experimental study of the Nb-AlOx-Nb FFO linewidth and other main parameters has been carried out in order to achieve this goal. Essential dependence of the FFO linewidth on its width and idle region dimension has been found. It makes...... possible an optimization of the FFO design and selection of the best FFO parameters for practical operation of the SIR....

  11. Carrier tracking algorithm based on joint acquisition of frequency locked loop and phase locked loop

    Directory of Open Access Journals (Sweden)

    Gao Kang

    2017-01-01

    Full Text Available Aiming at the problem of frequency step in the frequency lock loop (FLL - phase lock loop (PLL carrier tracking algorithm’s conversion state, presenting an improved algorithm: PLL and FLL joint acquisition to replace the single FLL acquires frequency, and deduce the loop state transition threshold. The simulation results show that the improved algorithm is more stable in the conversion process, and the loop performance is optimized. When the SNR is -10dB, and has the acceleration rate, the tracking loop does not have a frequency step at the time of conversion, achieving the design purpose.

  12. Calculation and experimental verification of a collimator with a Kerr lens for fibre laser mode locking

    Science.gov (United States)

    Zakharov, Ia. V.; Kuznetsov, A. G.; Podivilov, E. V.; Babin, S. A.

    2017-11-01

    We present the calculation and experimental verification of the operation of a collimator coupling a light beam into an optical fibre with an As2S3 nonlinear plate. It is shown that a Kerr lens formed in the plate with an increase in the peak pulse power leads to an increase in the output coupling ratio by about 15%, which can be used for the passive mode locking of a fibre laser.

  13. Concrete Growth and Fatigue Analysis of Chickamauga Lock Miter Gate Anchorages

    Science.gov (United States)

    2017-09-19

    to the operations and maintenance staff at Chickamauga Lock and Dam who went above and beyond the call of duty to allow ERDC to collect data...completed in 1940. Subsequently, minor structural problems developed in the early 1950s, primarily in the form of misalignment of rotating parts of the...riverside miter channels to calibrate a damage index model for the undamaged channels. The process followed these general steps: 1. Use observed gate

  14. Wavelength locking of silicon photonics multiplexer for DML-based WDM transmitter

    OpenAIRE

    Grillanda, Stefano; Ji, Ruiqiang; Morichetti, Francesco; Carminati, Marco; Ferrari, Giorgio; Guglielmi, Emanuele; Peserico, Nicola; Annoni, Andrea; Dede, Alberto; Nicolato, Danilo; Vannucci, Antonello; Klitis, Charalambos; Holmes, Barry; Sorel, Marc; Fu, Shengmeng

    2017-01-01

    We present a wavelength locking platform enabling the feedback control of silicon (Si) microring resonators (MRRs) for the realization of a 4 × 10 Gb/s wavelength-division-multiplexing (WDM) transmitter. Four thermally tunable Si MRRs are employed to multiplex the signals generated by four directly modulated lasers (DMLs) operating in the L-band, as well as to improve the quality of the DMLs signals. Feedback control is achieved through a field-programmable gate array controller by monitoring...

  15. Self-mode-locked vertical-external-cavity surface-emitting laser

    OpenAIRE

    Rahimi-Iman, Arash; Gaafar, Mahmoud; Möller, Christoph; Vaupel, Max; Zhang, Fan; Al-Nakdali, Dalia; Fedorova, Ksenia A.; Stolz, Wolfgang; Rafailov, Edik U.; Koch, Martin

    2016-01-01

    Ultrashort laser pulses from vertical-external-cavity surface-emitting lasers (VECSELs) have been receiving much attention in the semiconductor laser community since the first demonstration of sub-ps-pulsed devices more than a decade ago. Originally relying on semiconductor saturable-absorber mirrors for pulse formation, mode-locked operation has not only become accessible by using a variety of saturable absorbers, but also by using a saturable-absorber-free technique referred to as self-mode...

  16. Locke and the politics and theology of toleration

    OpenAIRE

    Stanton, T

    2006-01-01

    Locke's theory of toleration has been understood to rest on the claim that persecution was insufficient to instil either (i) true or (ii) sincere belief in people. Although Locke did indeed make both these claims, neither was fundamental to his theory. Locke was principally concerned to deny that persecution was necessary to instil true or sincere belief; its insufficiency to those ends he, and his contemporaries, took for granted. His denial of the necessity of persecution presupposed that h...

  17. Lumbar spinal canal MRI diameter is smaller in herniated disc cauda equina syndrome patients.

    Science.gov (United States)

    Korse, Nina S; Kruit, Mark C; Peul, Wilco C; Vleggeert-Lankamp, Carmen L A

    2017-01-01

    Correlation between magnetic resonance imaging (MRI) and clinical features in cauda equina syndrome (CES) is unknown; nor is known whether there are differences in MRI spinal canal size between lumbar herniated disc patients with CES versus lumbar herniated discs patients without CES, operated for sciatica. The aims of this study are 1) evaluating the association of MRI features with clinical presentation and outcome of CES and 2) comparing lumbar spinal canal diameters of lumbar herniated disc patients with CES versus lumbar herniated disc patients without CES, operated because of sciatica. MRIs of CES patients were assessed for the following features: level of disc lesion, type (uni- or bilateral) and severity of caudal compression. Pre- and postoperative clinical features (micturition dysfunction, defecation dysfunction, altered sensation of the saddle area) were retrieved from the medical files. In addition, anteroposterior (AP) lumbar spinal canal diameters of CES patients were measured at MRI. AP diameters of lumbar herniated disc patients without CES, operated for sciatica, were measured for comparison. 48 CES patients were included. At MRI, bilateral compression was seen in 82%; complete caudal compression in 29%. MRI features were not associated with clinical presentation nor outcome. AP diameter was measured for 26 CES patients and for 31 lumbar herniated disc patients without CES, operated for sciatica. Comparison displayed a significant smaller AP diameter of the lumbar spinal canal in CES patients (largest p = 0.002). Compared to average diameters in literature, diameters of CES patients were significantly more often below average than that of the sciatica patients (largest p = 0.021). This is the first study demonstrating differences in lumbar spinal canal size between lumbar herniated disc patients with CES and lumbar herniated disc patients without CES, operated for sciatica. This finding might imply that lumbar herniated disc patients with a

  18. Lumbar spinal canal MRI diameter is smaller in herniated disc cauda equina syndrome patients.

    Directory of Open Access Journals (Sweden)

    Nina S Korse

    Full Text Available Correlation between magnetic resonance imaging (MRI and clinical features in cauda equina syndrome (CES is unknown; nor is known whether there are differences in MRI spinal canal size between lumbar herniated disc patients with CES versus lumbar herniated discs patients without CES, operated for sciatica. The aims of this study are 1 evaluating the association of MRI features with clinical presentation and outcome of CES and 2 comparing lumbar spinal canal diameters of lumbar herniated disc patients with CES versus lumbar herniated disc patients without CES, operated because of sciatica.MRIs of CES patients were assessed for the following features: level of disc lesion, type (uni- or bilateral and severity of caudal compression. Pre- and postoperative clinical features (micturition dysfunction, defecation dysfunction, altered sensation of the saddle area were retrieved from the medical files. In addition, anteroposterior (AP lumbar spinal canal diameters of CES patients were measured at MRI. AP diameters of lumbar herniated disc patients without CES, operated for sciatica, were measured for comparison.48 CES patients were included. At MRI, bilateral compression was seen in 82%; complete caudal compression in 29%. MRI features were not associated with clinical presentation nor outcome. AP diameter was measured for 26 CES patients and for 31 lumbar herniated disc patients without CES, operated for sciatica. Comparison displayed a significant smaller AP diameter of the lumbar spinal canal in CES patients (largest p = 0.002. Compared to average diameters in literature, diameters of CES patients were significantly more often below average than that of the sciatica patients (largest p = 0.021.This is the first study demonstrating differences in lumbar spinal canal size between lumbar herniated disc patients with CES and lumbar herniated disc patients without CES, operated for sciatica. This finding might imply that lumbar herniated disc patients with

  19. Anal cancer; Cancer du canal anal

    Energy Technology Data Exchange (ETDEWEB)

    Fesneau, M.; Champeaux-Orange, E. [Service de radiotherapie, Centre regional universitaire de cancerologie Henry-S.-Kaplan CHU de Tours, Hopital Bretonneau, 37 - Tours (France); Champeaux-Orange, E. [Service d' oncologie-radiotherapie, Centre hospitalier regional d' Orleans, 45 - Orleans (France); Hennequin, C. [Service de cancerologie-radiotherapie, hopital Saint-Louis, 75 - Paris (France)

    2010-07-01

    Anal canal epidermoid carcinomas represent 1.2% of digestive cancers and 6% of ano-rectal cancers. For localized diseases, the treatment is based on radiotherapy with or without chemotherapy (5-FU and cisplatin or mitomycin), according to tumour and nodal extension. The recommended treatment dose is 45 Gy in the anal canal, the mesorectum, para-rectal lymph nodes, and inguinal lymph nodes. An additional dose of 15 to 20 Gy is delivered in the initial tumour for good responders. Salvage surgery is necessary in case of poor response. The organs at risk to be considered are bladder, femur heads, small intestine and vulva. The objective of this work is to summarize the epidemiological and radio-anatomic and prognostic characteristics of this tumour. The conformal radiotherapy technique is illustrated by a case report. (authors)

  20. Root Canal Filling after Revascularization/Revitalization.

    Science.gov (United States)

    Plascencia, Hugo; Cruz, Álvaro; Díaz, Mariana; Jiménez, Ana Laura; Solís, Rodrigo; Bernal, Cesar

    Revascularization/revitalization therapy is considered an alternative procedure for management of teeth with an immature apex and necrotic pulp, mainly when root development is interrupted in the early phases of formation. However, this clinical treatment protocol should be considered a permanent procedure? A maxillary central incisor with a previous and successful RR treatment was intentionally filled with a biocompatible material with the periapical tissues due to the patient's lack of adherence to the follow-up protocol. The 20-month follow-up showed absence of clinical, radiological and tomographic signs and symptoms of an endodontic re-infection. This case demonstrates that once the increased thickening of the canal walls, incrementing the root length, apical closure and the total resolution of the apical lesion are observed, the main canal of a previously treated tooth with an RR procedure can be filled.

  1. Squamous cell carcinoma of the anal canal.

    LENUS (Irish Health Repository)

    Martin, F T

    2012-01-31

    Squamous cell carcinoma ofthe anal canal represents 1.5% of all malignancies affectingthe gastrointestinal tract. Over the past 20 years dramatic changes have been seen in both the epidemiological distribution of the disease and in the therapeutic modalities utilised to manage it. CLINICAL MANAGEMENT: Historically abdominoperineal resection had been the treatment of choice with local resection reserved for early stage disease. Work by Nigro et al. has revolutionised how we currently manage carcinoma of the anal canal, demonstrating combined modality chemoradiotherapy as an appropriate alternative to surgical resection with the benefit of preserving sphincter function. Surgery is then reserved for recurrent disease with salvage abdominoperineal resection. This article reviews current literature and highlights the changing therapeutic modalities with selected clinical cases

  2. Neuronal hyperplasia in the anal canal

    DEFF Research Database (Denmark)

    Fenger, C; Schrøder, H D

    1990-01-01

    In a consecutive series of minor surgical specimens from the anal canal, neuronal hyperplasia was found in nine of 56 haemorrhoidectomy specimens and in four of 23 fibrous polyps. In an additional series of 14 resections of the anal canal, neuronal hyperplasia was present in six cases, of which...... five showed haemorrhoids. In all cases, neuronal hyperplasia was located in the submucosa beneath squamous epithelium and extended over an area from 5 to 12 mm. Immunohistochemically, the foci of hyperplasia were found to consist of both neuronal and Schwann cell components. Staining for vasoactive...... intestinal peptide, neuropeptide Y and calcitonin gene related peptide, did not demonstrate any increased terminal density. It is suggested that anal neuronal hyperplasia in these cases represents an acquired lesion due to local mechanical influence....

  3. Self-mode-locked 2 μm Tm(3+)-doped double-clad fiber laser with a simple linear cavity.

    Science.gov (United States)

    Liu, Chun; Luo, Zhengqian; Huang, Yizhong; Qu, Biao; Cheng, Huihui; Wang, Ying; Wu, Duanduan; Xu, Huiying; Cai, Zhiping

    2014-02-10

    We demonstrate the self-mode-locking operation of a thulium (Tm)-doped fiber laser (TDFL) with a simple linear cavity. Since the laser cavity does not include any specific mode-locker, we experimentally investigate and analyze the self-mode-locking mechanism. The mode-locking operation is attributed to the combination of the self-phase modulation effect and the weak saturable absorption of the high-concentration Tm-doped fiber. The mode-locked TDFL operates at a central wavelength of 1985.5 nm with the 3 dB spectral linewidth of 0.18 nm. The self-mode-locking generates a large pulse energy of 32.7 nJ with a pulsed repetition rate of 2.05 MHz and is stable with a radio-frequency signal-to-noise ratio of more than 54 dB. To the best of our knowledge, it is the first demonstration of a 2 μm Tm-doped fiber laser mode-locked by such technique.

  4. The shape of the human lumbar vertebral canal A forma do canal vertebral lombar humano

    Directory of Open Access Journals (Sweden)

    Edmundo Zarzur

    1996-09-01

    Full Text Available Literature on the anatomy of the human vertebral column characterizes the shape of the lumbar vertebral canal as triangular. The purpose of the present study was to determine the precise shape of the lumbar vertebral canal. Ten lumbar vertebral columns of adult male cadavers were dissected. Two transverse sections were performed in the third lumbar vertebra. One section was performed at the level of the lower border of the ligamenta flava, and the other section was performed at the level of the pedicles. The shape of the lumbar vertebral canal at the level of the pedicles tends to be oval or circular, whereas the shape of the lumbar vertebral canal at the level of the lower border of the ligamenta flava is triangular. Thus, the shape of the human lumbar vertebral canal is not exclusively triangular, as reported in the literature. It is related to the level of the transversal section performed on the lumbar vertebra. This finding should be taken into consideration among factors involved in the spread of solutions introduced into the epidural space.A literatura sobre a anatomia da coluna vertebral descreve como sendo triangular o formato do canal vertebral na região lombar. O objetivo deste estudo é determinar a real forma do canal da coluna vertebral lombar.Dez colunas vertebrais de cadáveres de homens adultos foram dissecadas. Dois cortes transversais foram executados na terceira vértebra lombar. Um corte foi feito no nível das bordas inferiores de dois ligamentos amarelos vizinhos e o outro corte foi transversal, no nível dos pedículos. A forma do canal vertebral variou: no nível dos pedículos ela tende a ser oval ou circular e junto às bordas inferiores dos ligamentos amarelos passa a ser triangular. Portanto, a forma do canal vertebral lombar não é somente triangular; ela depende do nível em que se faz o corte transversal da vértebra. Estes achados devem ser levados em consideração entre os fatores envolvidos na difusão das

  5. Koebner phenomenon of the ear canal skin.

    LENUS (Irish Health Repository)

    Young, O

    2009-02-01

    The Koebner phenomenon originally described the appearance of psoriatic lesions in the uninvolved skin of patients with psoriasis as a consequence of trauma. We describe a case of concurrent lichen planus and sarcoidosis in the auditory canal, which represents an unusual manifestation of the Koebner phenomenon. This is the first case of concurrent lichen planus and sarcoidosis in the head and neck region and highlights the need for biopsy to allow accurate histopathological diagnosis and treatment.

  6. Koebner phenomenon of the ear canal skin.

    LENUS (Irish Health Repository)

    Young, O

    2012-02-01

    The Koebner phenomenon originally described the appearance of psoriatic lesions in the uninvolved skin of patients with psoriasis as a consequence of trauma. We describe a case of concurrent lichen planus and sarcoidosis in the auditory canal, which represents an unusual manifestation of the Koebner phenomenon. This is the first case of concurrent lichen planus and sarcoidosis in the head and neck region and highlights the need for biopsy to allow accurate histopathological diagnosis and treatment.

  7. Root canal filling using Resilon: a review.

    LENUS (Irish Health Repository)

    Shanahan, D J

    2011-07-01

    Root canal treatment is achieved by chemo-mechanical debridement of the root canal system followed by filling. The filling material \\'entombs\\' residual bacteria and acts as a barrier which prevents the entrance of oral microorganisms and reinfection of the root canal system through microleakage. However, filling with contemporary root filling materials such as gutta-percha offers limited long-term resistance to microorganisms; as a result other materials such as Resilon have been investigated as alternatives. The aim of this review was to analyse the literature to consider whether Resilon is a suitable root canal filling material. A MEDLINE and Cochrane library search including various keyword searches identified several papers which investigated or discussed Resilon or RealSeal\\/Epiphany. Analysis of the literature demonstrated that the bulk of the literature is in vitro in nature, based largely on leakage-type studies, and demonstrates a wide variety of methodologies with conflicting findings; as a result meaningful conclusions are difficult. Within the limit of these in vitro studies Resilon appears to perform adequately in comparison to gutta-percha, however, as a result of the questionable merit of such studies, it cannot presently be considered an evidence-based alternative to the current gold standard gutta-percha. It is imperative that before Resilon is considered as a replacement material, a better understanding of the physical properties of the resin sealer and the reality of the adhesive \\'monoblock\\' are elucidated. The literature also demonstrates a paucity of quality long-term clinical outcome studies which will need to be addressed before firm conclusions can be reached.

  8. Carotid canal dehiscence in the human skull

    Energy Technology Data Exchange (ETDEWEB)

    Pastor Vazquez, J.F.; Gil Verona, J.A. [Department of Anatomy, Faculty of Medicine, University of Valladolid, Ramon y Cajal, 7, E-47005 Valladolid (Spain); Garcia Porrero, M. [Department of Radiology, Faculty of Medicine, University of Valladolid (Spain)

    1999-06-01

    Abnormalities of the floor of the carotid canal have been studied in 538 skulls. These abnormalities range from a fissure to total absence of the floor. This variation may be caused by abnormalities of the internal carotid artery or deficiencies in ossification of the skull base. CT suggests that these changes should be taken into account by surgeons working on the skull base. (orig.) With 4 figs., 8 refs.

  9. Roentgenographic study of the mandibular canal

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Hyung Kyu [Dept. of Oral Radiology, College of Dentistry, Seoul National University, Seoul (Korea, Republic of)

    1980-11-15

    The mandibular canal must be considered carefully during the surgical treatment, especially surgical extraction of the impacted tooth and intraosseous implant, because it contains the important inferior alveolar nerve and vessels. The author investigated the curvature of the mandibular canal and its relation to the mandibular molars and positional relation between the mental foramen and the mandibular premolars in orthopantomogram. The materials consisted of 441 orthopantomograms divided four groups; Group I consisted of 56 males and 44 females from 1 to 6 years of age, Group II consisted of 58 males and 45 females from 7 to 12 years of age, Group III consisted of 65 males and 33 females from 13 to 18 years of age, Group IV consisted of 86 males and 54 females over 19 years of age. The results were as followings; 1. The curvature of mandibular canal was 144.50 .deg. in Group II, 148.11 .deg. in Group III, 147.33 .deg. in Group IV. 2. The curvature of mandibular canal was located most frequently on the area between mandibular 1st molar and mandibular 2nd molar in Group I (42%) and on the mandibular 2nd molar area in Group II (54%), Group III (59%), Group IV (53%). 3. The position of mental foramen was most frequently below the mandibular 1st premolar in Group I (58%), between the mandibular 1st premolar and the 2nd premolar in Group II (62%), Group III (47%), and below the mandibular 2nd premolar in Group IV (58%).

  10. Lesions in the external auditory canal

    Directory of Open Access Journals (Sweden)

    Priyank S Chatra

    2011-01-01

    Full Text Available The external auditory canal is an S- shaped osseo-cartilaginous structure that extends from the auricle to the tympanic membrane. Congenital, inflammatory, neoplastic, and traumatic lesions can affect the EAC. High-resolution CT is well suited for the evaluation of the temporal bone, which has a complex anatomy with multiple small structures. In this study, we describe the various lesions affecting the EAC.

  11. Low-power wide-locking-range injection-locked frequency divider for OFDM UWB systems

    Energy Technology Data Exchange (ETDEWEB)

    Yin Jiangwei; Li Ning; Zheng Renliang; Li Wei; Ren Junyan, E-mail: lining@fudan.edu.c [State Key Laboratory of ASIC and System, Fudan University, Shanghai 201203 (China)

    2009-05-01

    This paper describes a divide-by-two injection-locked frequency divider (ILFD) for frequency synthesizers as used in multiband orthogonal frequency division multiplexing (OFDM) ultra-wideband (UWB) systems. By means of dual-injection technique and other conventional tuning techniques, such as DCCA and varactor tuning, the divider demonstrates a wide locking range while consuming much less power. The chip was fabricated in the Jazz 0.18 mum RF CMOS process. The measurement results show that the divider achieves a locking range of 4.85 GHz (6.23 to 11.08 GHz) at an input power of 8 dBm. The core circuit without the test buffer consumes only 3.7 mA from a 1.8 V power supply and has a die area of 0.38 x 0.28 mm{sup 2}. The wide locking range combined with low power consumption makes the ILFD suitable for its application in UWB systems.

  12. 33 CFR 207.718 - Navigation locks and approach channels, Columbia and Snake Rivers, Oreg. and Wash.

    Science.gov (United States)

    2010-07-01

    ... schedule and any changes to the schedule will be issued at least 30 days prior to implementation. Prior to... subject to falling overboard. (t) Handling valves, gates, bridges, and machinery. No person, unless authorized by the Lock Master, shall open or close any bridge, gate, valve, or operate any machinery in...

  13. Semiconductor laser irradiation improves root canal sealing during routine root canal therapy.

    Science.gov (United States)

    Su, Dandan; Hu, Xingxue; Wang, Dashan; Cui, Ting; Yao, Ruyong; Sun, Huibin

    2017-01-01

    To evaluate the effect of semiconductor laser irradiation on root canal sealing after routine root canal therapy (RCT). Sixty freshly extracted single-rooted human teeth were randomly divided into six groups (n = 10). The anatomic crowns were sectioned at the cementoenamel junction and the remaining roots were prepared endodontically with conventional RCT methods. Groups A and B were irradiated with semiconductor laser at 1W for 20 seconds; Groups C and D were ultrasonically rinsed for 60 seconds as positive control groups; Groups E and F without treatment of root canal prior to RCT as negative control groups. Root canal sealing of Groups A, C and E were evaluated by measurements of apical microleakage. The teeth from Groups B, D and F were sectioned, and the micro-structures were examined with scanning electron microscopy (SEM). One way ANOVA and LSD-t test were used for statistical analysis (α = .05). The apical sealing of both the laser irradiated group and the ultrasonic irrigated group were significantly different from the control group (p0.5). SEM observation showed that most of the dentinal tubules in the laser irradiation group melted, narrowed or closed, while most of the dentinal tubules in the ultrasonic irrigation group were filled with tooth paste. The application of semiconductor laser prior to root canal obturation increases the apical sealing of the roots treated.

  14. Semiconductor laser irradiation improves root canal sealing during routine root canal therapy.

    Directory of Open Access Journals (Sweden)

    Dandan Su

    Full Text Available To evaluate the effect of semiconductor laser irradiation on root canal sealing after routine root canal therapy (RCT.Sixty freshly extracted single-rooted human teeth were randomly divided into six groups (n = 10. The anatomic crowns were sectioned at the cementoenamel junction and the remaining roots were prepared endodontically with conventional RCT methods. Groups A and B were irradiated with semiconductor laser at 1W for 20 seconds; Groups C and D were ultrasonically rinsed for 60 seconds as positive control groups; Groups E and F without treatment of root canal prior to RCT as negative control groups. Root canal sealing of Groups A, C and E were evaluated by measurements of apical microleakage. The teeth from Groups B, D and F were sectioned, and the micro-structures were examined with scanning electron microscopy (SEM. One way ANOVA and LSD-t test were used for statistical analysis (α = .05.The apical sealing of both the laser irradiated group and the ultrasonic irrigated group were significantly different from the control group (p0.5. SEM observation showed that most of the dentinal tubules in the laser irradiation group melted, narrowed or closed, while most of the dentinal tubules in the ultrasonic irrigation group were filled with tooth paste.The application of semiconductor laser prior to root canal obturation increases the apical sealing of the roots treated.

  15. Comparison of Bacterial Leakage between 3 Different Root Canal Obturation Techniques in Oval Shaped Canals

    Directory of Open Access Journals (Sweden)

    Eshagh-ali Saberi

    2014-06-01

    Full Text Available Introduction: The purpose of this study was to evaluate the sealing ability of 3 obturation techniques in oval-shaped canals by bacterial leakage assessment. Methods: Sixty mandibular incisors with oval canals were selected after providing buccolingual and mesiodistal radiographs. The teeth were sectioned at a 10 mm distance from the apex. After instrumentation, the teeth were divided into 3 groups and the canals in the three groups were obturated with lateral condensation (G1, warm vertical condensation (G2 and thermoplasticized injectable gutta percha (G3. The teeth were exposed to human saliva. Observing the turbidity of the BHI broth for a period of 63 days the number of days required for the complete contamination of root canals was recorded. The data were analyzed using descriptive statistical methods and Kruskal-Wallis test with SPSS statistical software. Results: Warm vertical condensation (G2 needed a significantly greater average time for leakage than the two other methods. No significant differences were found between lateral condensations and thermoplasticized injectable G.P techniques. Conclusion: warm vertical condensation provides a better seal against bacterial leakage than lateral condensation and obtura II method in obturating oval-canals.

  16. Pulse growth dynamics in laser mode locking

    Science.gov (United States)

    Popov, Mark; Gat, Omri

    2018-01-01

    We analyze theoretically and numerically the nonlinear process of pulse formation in mode-locked lasers, starting from a perturbation of a continuous wave. Focusing on weak-to-moderate dispersion systems, we show that pulse growth is initially slow, dominated by a cascade of energy from low to high axial modes, followed by fast strongly nonlinear growth, and finally relaxation to the stable pulse wave form. The pulse grows initially by condensing a fixed amount of energy into a decreasing time interval, with peak power growing toward a finite-time singularity that is checked when the gain bandwidth is saturated by the pulse.

  17. Locks Restaurant Group Lunch Menu 2017

    OpenAIRE

    Locks

    2017-01-01

    Introducing Locks 1 Windsor Terrace, bringing the best in modern Irish food to a much loved venue in Dublin 8. Our goal here is to warmly welcome our guests into one of Dublin’s best dining rooms with an exciting and constantly evolving menu, extensive wine & bar list, great music and laid-back atmosphere. We want our customers to come back to us time and time again for both the big and small events in their lives. Upstairs we have beautiful private rooms perfect for parties, and our Head Che...

  18. Locks Restaurant Sunday Lunch Menu 2017

    OpenAIRE

    Locks

    2017-01-01

    Introducing Locks 1 Windsor Terrace, bringing the best in modern Irish food to a much loved venue in Dublin 8. Our goal here is to warmly welcome our guests into one of Dublin’s best dining rooms with an exciting and constantly evolving menu, extensive wine & bar list, great music and laid-back atmosphere. We want our customers to come back to us time and time again for both the big and small events in their lives. Upstairs we have beautiful private rooms perfect for parties, and our Head Che...

  19. Advanced frequency synthesis by phase lock

    CERN Document Server

    Egan, William F

    2011-01-01

    "An addendum to the popular Frequency Synthesis by Phase Lock, 2nd ed, this book describes sigma-delta, a frequency synthesis technique that has gained prominence in recent years. In addition, Simulink will be employed extensively to guide the reader. Fractional-n, the still-used forerunner to sigma-delta, is also discussed. Sequences of simulated results allow the reader to gain a deeper understanding while detailed appendices provide information from various stages of development. Simulation models discussed in the chapters that are available online."--Provided by publisher.

  20. Gapless Color-Flavor-Locked Quark Matter

    DEFF Research Database (Denmark)

    Alford, Mark; Kouvaris, Christoforos; Rajagopal, Krishna

    2004-01-01

    In neutral cold quark matter that is sufficiently dense that the strange quark mass M_s is unimportant, all nine quarks (three colors; three flavors) pair in a color-flavor locked (CFL) pattern, and all fermionic quasiparticles have a gap. We argue that as a function of decreasing quark chemical...... a linear combination Qtilde of electric and color charges, but it is a Qtilde-conductor with a nonzero electron density. These electrons and the gapless quark quasiparticles make the low energy effective theory of the gapless CFL phase and, consequently, its astrophysical properties are qualitatively...

  1. Obituary: Martha Locke Hazen, 1931-2006

    Science.gov (United States)

    Williams, Thomas R.; Willson, Lee Anne

    2007-12-01

    Longtime Harvard Curator of Astronomical Photographs and AAVSO officer Martha Hazen passed away on 23 December 2006 at Hingham, Massachusetts, after a short illness due to acute myelogenous leukemia. One of four children of Harold Locke and Katherine (neé Salisbury) Hazen, Martha was born in Cambridge, Massachusetts, on 15 July 1931, and raised in the Town of Belmont, near Cambridge, where she lived for most of her life. Her father coined the term "servo-mechanism" while serving as an engineering professor and dean for graduate students at the Massachusetts Institute of Technology. Her mother majored in chemistry at Mount Holyoke College. After receiving an A.B. in astronomy from Mount Holyoke College in 1953, Martha earned a Ph.D. in astronomy in 1958 from the University of Michigan, defending a dissertation on the distribution of intensity in elliptical galaxies in the Virgo cluster. Martha's marriage to William Liller in 1959, and the births of two children, inevitably slowed down her progress in observational astronomy. As a research fellow of the Harvard College Observatory, Martha continued to observe two to three weeks a year in Chile, and to reduce those observations and publish the results for sixteen years. Martha's first publication, at least as far as Astrophysics Data System includes the literature, was with Alice Farnsworth on the 1952 occultations of stars by the Moon, published in the Astronomical Journal (1953). In 1958 she joined L. R. Doherty and D. H. Menzel on a short note about the calculation of line profiles in a stratified atmosphere, her only theory paper. Martha's most cited paper is "The Distribution of Intensity in Elliptical Galaxies of the Virgo Cluster," (ApJ, 132, p.306, 1960). There she acknowledges Allan Sandage for suggesting the problem and providing some of the data. Her second most cited paper is "Photometric histories of QSOs - Two QSOs with large light amplitude," (Liller, M. H. & Liller, W., ApJ (Letters), 199, p. L133-L

  2. Anterior canal lithiasis: diagnosis and treatment.

    Science.gov (United States)

    Casani, Augusto Pietro; Cerchiai, Niccolò; Dallan, Iacopo; Sellari-Franceschini, Stefano

    2011-03-01

    To describe the clinical and oculographic features in patients with anterior semicircular canal benign paroxysmal positional vertigo and to determine the efficacy of a canalith repositioning procedure for its management. Case series with chart review of patients presenting positional vertigo and positional downbeating nystagmus during a 2-year period. Outpatients' tertiary referral center for balance disorders. Eighteen patients suffering from positional vertigo and presenting positional downbeating nystagmus were treated with a maneuver based on a modification of the procedure proposed by Crevits. disappearance of positional downbeating nystagmus. Positional downbeating nystagmus was elicited unilaterally with the Dix-Hallpike maneuver in 6 cases. In 4 patients, it was triggered by both left and right Dix-Hallpike tests. In 8 patients, the positional nystagmus was elicited by a straight head-hanging maneuver. The positional nystagmus was purely downbeating in 12 patients. In the remaining, a torsional component was detected. After the treatment, only 1 patient showed positional nystagmus at 30 days. In anterior canal benign paroxysmal positional vertigo, the presence of a positional downbeating nystagmus in response to positional tests is key for diagnosis. In a significant number of patients, the affected side may not be detected because of the inconstant presence of a torsional component. Treatment with a simplified maneuver based on Crevits's technique can be considered an effective method for the treatment of anterior canal lithiasis, especially when the affected side cannot be detected clearly.

  3. Expanded transcanal transpromontorial approach to the internal auditory canal: Pilot clinical experience.

    Science.gov (United States)

    Presutti, Livio; Alicandri-Ciufelli, Matteo; Bonali, Marco; Rubini, Alessia; Pavesi, Giacomo; Feletti, Alberto; Masotto, Barbara; Anschuetz, Lukas; Marchioni, Daniele

    2017-11-01

    The aim of this study was to describe and evaluate the feasibility of an expanded transcanal transpromontorial approach, developed from the exclusive endoscopic transcanal transpromontorial approach. Retrospective case series. Retrospective chart review of 10 patients operated by an expanded transcanal transpromontorial approach in two tertiary referral centers (University Hospital of Modena, Italy and University Hospital of Verona, Italy). Data from charts and video documentation were collected and analyzed. Between April 2015 and January 2016, 10 patients underwent an expanded transcanal transpromontorial approach for vestibular schwannoma Koos stage I or II and were enrolled in the study. The size of the tumors ranged from 7 to 19 mm in maximum diameter. A gross total resection was achieved in all cases. One subject experienced postoperative cerebrospinal fluid otorhinorrhea and three subjects experienced temporary postoperative facial weakness, all of which completely resolved. The mean follow-up was 5 months. The expanded transcanal transpromontorial approach allowed bimanual dissection using a microscopic technique for the treatment of pathologies of the internal auditory canal and cerebellopontine angle. This novel approach resulted in minimal morbidity and comparable facial nerve preservation rates to the traditional approaches to the internal auditory canal. The expanded transpromontorial approach to the internal auditory canal holds promise for addressing pathology in this region of the temporal bone from the external auditory canal. 4. Laryngoscope, 127:2608-2614, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

  4. Location of the root canal: Direct vision versus surgical microscope. In-vitro study.

    Directory of Open Access Journals (Sweden)

    Gabriela Sánchez

    2012-07-01

    Full Text Available The inability to properly identify the entrance to the root system, main and accessories, is one of the causes of endodontic failure. Hence arises the need to incorporate new technologies to improve the visibility of the access cavity to the location of the entrance to one of the root. The purpose of this study was to compare whether there is a difference between the location of root canals of human permanent molars through direct vision and using the surgical microscope. We examined 100 extracted human permanent molars first by direct vision and then using a surgical microscope to determine the number of root canals located. The difference was established for obtaining the real number of channels to make the cut root. Our study indicates that the number of root canals located increase in a 11% with the use of surgical microscope which is reflected in special conduits accessories which is consistent with other studies performed. It can be concluded from this study that the use of a surgical microscope were located a greater number of ducts in relation to the use of direct vision therefore is considered a useful tool to aid the clinician inconventional endodontic treatment, offering a fully operative fieldilluminated and magnified viewing with great detail, the floor of the chamber and the entrance to all canals, which is the key to success in endodontics.

  5. Rare Case of Anal Canal Signet Ring Cell Carcinoma Associated with Perianal and Vulvar Pagetoid Spread

    Directory of Open Access Journals (Sweden)

    Na Rae Kim

    2016-05-01

    Full Text Available A 61-year-old woman was referred to surgery for incidentally found colonic polyps during a health examination. Physical examination revealed widespread eczematous skin lesion without pruritus in the perianal and vulvar area. Abdominopelvic computed tomography showed an approximately 4-cm-sized, soft tissue lesion in the right perianal area. Inguinal lymph node dissection and Mils’ operation extended to perianal and perivulvar skin was performed. Histologically, the anal canal lesion was composed of mucin-containing signet ring cells, which were similar to those found in Pagetoid skin lesions. It was diagnosed as an anal canal signet ring cell carcinoma (SRCC with perianal and vulvar Pagetoid spread and bilateral inguinal lymph node metastasis. Anal canal SRCC is rare, and the current case is the third reported case in the English literature. Seven additional cases were retrieved from the world literature. Here, we describe this rare case of anal canal SRCC with perianal Pagetoid spread and provide a literature review.

  6. Seepage study of the South Bend, Richfield, and Vermillion Canals, Sevier County, Utah

    Science.gov (United States)

    Herbert, L.R.; Smith, G.J.

    1989-01-01

    A seepage investigation was made in 1987 on selected reaches of the South Bend, Richfield, and Vermillion Canals in Sevier County, Utah, to determine gains or losses in discharge.  Fluctuations in discharge were adjusted using information from stage recorders operated at selected locations during each set of discharge measurements. The investigation showed a net gain of 0.2 cubic foot per second in the South Bend canal: the upper reach gained 1.5 cubic feet per second, the two middle reaches together lost 2.5 cubic feet per second, and the lower reach gained 1.2 cubic feet per second.  The Richfield Canal showed a net loss of 2.4 cubic feet per second: the two upper reaches together lost 4.4 cubic feet per second and the two lower reaches together gained 2.0 cubic feet per second.  The Vermillion canal showed a net loss of 0.2 cubic foot per second: the upper reach gained 2.3 cubic feet per second and the lower reach lost 2.5 cubic feet per second.

  7. Diode-pumped Kerr-lens mode-locked Yb:LYSO laser with 61fs pulse duration.

    Science.gov (United States)

    Tian, Wenlong; Wang, Zhaohua; Wei, Long; Peng, Yingnan; Zhang, Jinwei; Zhu, Zheng; Zhu, Jiangfeng; Han, Hainian; Jia, Yulei; Zheng, Lihe; Xu, Jun; Wei, Zhiyi

    2014-08-11

    A stable diode pumped Kerr-lens mode-locked (KLM) Yb:LuYSiO5 (Yb:LYSO) laser of generating 61 fs pulses at a central wavelength of 1055.4 nm is experimentally demonstrated. This is, to the best of our knowledge, the first demonstration of femtosecond KLM operation in Yb:LYSO laser, and it is believed that 61 fs is the shortest pulse duration ever produced from an Yb-doped orthosilicate laser. The average output power of the mode-locked laser is 40 mW and the repetition rate is 113 MHz.

  8. Sub-femtosecond timing jitter, all-fiber, CNT-mode-locked Er-laser at telecom wavelength.

    Science.gov (United States)

    Kim, Chur; Bae, Sangho; Kieu, Khanh; Kim, Jungwon

    2013-11-04

    We demonstrate a 490-attosecond timing jitter (integration bandwidth: 10 kHz - 39.4 MHz) optical pulse train from a 78.7-MHz repetition rate, all-fiber soliton Er laser mode-locked by a fiber tapered carbon nanotube saturable absorber (ft-CNT-SA). To achieve this jitter performance, we searched for a net cavity dispersion condition where the Gordon-Haus jitter is minimized while maintaining stable soliton mode-locking. Our result shows that optical pulse trains with well below a femtosecond timing jitter can be generated from a self-starting and robust all-fiber laser operating at telecom wavelength.

  9. 1.34 µm picosecond self-mode-locked Nd:GdVO4 watt-level laser

    Science.gov (United States)

    Han, Ming; Peng, Jiying; Li, Zuohan; Cao, Qiuyuan; Yuan, Ruixia

    2017-01-01

    With a simple linear configuration, a diode-pumped, self-mode-locked Nd:GdVO4 laser at 1.34 µm is experimentally demonstrated for the first time. Based on the aberrationless theory of self-focusing and thermal lensing effect, through designing and optimizing the resonator, a pulse width as short as 9.1 ps is generated at a repetition rate of 2.0 GHz and the average output power is 2.51 W. The optical conversion efficiency and the slope efficiency for the stable mode-locked operation are approximately 16.7% and 19.2%, respectively.

  10. Generation of sub-100-fs pulses from a CW mode-locked chromium-doped forsterite laser

    Science.gov (United States)

    Seas, A.; Petricevic, V.; Alfano, R. R.

    1992-01-01

    Generation of femtosecond pulses from a continuous-wave mode-locked chromium-doped forsterite laser is reported. The forsterite laser was actively mode locked by using an acoustooptic modulator operating at 78 MHz with two Brewster high-dispersion glass prisms for intracavity chirp compensation. Transform-limited sub-100-fs pulses were routinely generated in the TEM(00) mode with 85 mW of continuous power (with 1 percent output coupler), tunable over 1230-1280 nm. The shortest pulses measured had a 60-fs pulse width.

  11. Diagnostic values of coronal section with MPR method in magnetic resonance imaging of canal stenotic change

    Energy Technology Data Exchange (ETDEWEB)

    Kuroda, Mana; Haruhara, Shoutaro; Soh, Katsuhiro; Yokouchi, Junichi; Matsuda, Hiromichi; Inoue, Shingo; Kakizaki, Dai; Abe, Kimihiko (Tokyo Medical Coll. (Japan))

    1990-03-01

    During a 2-year period, 300 patients were screened for canal stenotic change with surface-coil MR images, and T1-weighted coronal scan was performed on 65 patients with typical radiculopathy including 45 cases of lumbar disk herniation to evaluate the effectiveness of coronal section with MPR (multi-planar reconstruction) method in pre and post-operative assessment of canal stenotic change. Coronal section with MPR method in MRI of lumbar spine has advantages in patients with radiculopathy. Although it is as sensitive as myelography in detecting the pathological site, nerve root damage can be detected more obviously by MRI coronal section with MPR method than by myelography. As bilateral nerve roots and other contents of the foramen are figurized in the same image, the shift of the root and the decrease of the fat layer surrounding the roots can be more easily detected. Adding coronal imaging to MR examination is a viable alternative to pre-operative myelography. (author).

  12. Mechanical evaluation of fourth-generation composite femur hybrid locking plate constructs.

    Science.gov (United States)

    Goswami, Tarun; Patel, Vinit; Dalstrom, David J; Prayson, Michael J

    2011-09-01

    Locking compression plates are routinely used for open reduction and internal fixation of fractures. Such plates allow for locking or non-locking screw placement in each hole. A combined use of both types of screw application for stabilization of a fracture is commonly applied and referred to as hybrid internal fixation. Locking screws improve the stability of the fixation construct but at the expense of significant additional cost. This study experimentally analyzes various combinations of locking and non-locking screws under simultaneous axial and torsional loading to determine the optimal hybrid locking plate-screw construct in a fourth generation composite femur. Clinically it is necessary to ensure adequate fixation stability in a worse case fracture-bone quality scenario. A locking screw near the fracture gap increased the axial and torsional strength of the locked plate system. Greater removal torque remained in non-locked screws adjacent to locked screws compared to an all non-locking screws control group.

  13. Design of a lock-amplifier circuit

    Science.gov (United States)

    Liu, H.; Huang, W. J.; Song, X.; Zhang, W. Y.; Sa, L. B.

    2017-01-01

    The lock-in amplifier is recovered by phase sensitive detection technique for the weak signal submerged in the noise background. This design is based on the TI ultra low power LM358, INA129, OPA227, OP07 and other chips as the core design and production of the lock-in amplifier. Signal generator by 10m ohms /1K ohm resistance points pressure network 10 mu V 1mV adjustable sine wave signal s (T). The concomitant interference signal together through the AC amplifier and band-pass filter signal x (T), on the other hand reference signal R (T) driven by square wave phase shift etc. steps to get the signal R (T), two signals and by phase sensitive detector are a DC full wave, again through its low pass filter and a DC amplifier to be measured signal more accurate detection, the final circuit through the AD conversion and the use of single-chip will display the output.

  14. Lei natural e lei civil em Locke

    Directory of Open Access Journals (Sweden)

    Gustavo Hessmann Dalaqua

    2015-04-01

    Full Text Available Resumo: O artigo aborda a relação entre lei natural e lei civil na filosofia de John Locke. Embora leituras consagradas tenham afirmado que a relação entre ambas é dedutiva, este artigo tentará apresentar uma interpretação diferente, qual seja, a de que a relação entre lei civil e lei natural é de determinação. Longe de ser mera dedução de uma lei natural imutável, a lei civil possui papel determinante com relação à lei natural. Como mostraremos, esta interpretação realça algo que Locke tinha em alta estima: o caráter deliberativo da lei natural. A deliberação dos cidadãos na legislatura cria, em certa medida, a lei natural. Os cidadãos são livres para determinar a lei, e a participação em tal determinação é crucial para a manutenção de sua liberdade política. Nesse sentido, como veremos, a liberdade política lockiana é tributária do republicanismo.

  15. Prospective Randomized Comparison of Locked Plates Versus Nonlocked Plates for the Treatment of High-Energy Pilon Fractures.

    Science.gov (United States)

    dʼHeurle, Albert; Kazemi, Namdar; Connelly, Camille; Wyrick, John D; Archdeacon, Michael T; Le, Theodore T

    2015-09-01

    To compare the radiographic and functional outcome of patients with high-energy pilon fractures treated with locked versus nonlocked plates. Randomized prospective trial. Academic level 1 trauma center. Between December 2006 and December 2008, 60 consecutive patients with 62 AO/OTA type A, B, and C tibial pilon fractures were enrolled in the study. Thirty-two of the fractures were treated using locked plates and 29 were treated with nonlocked plates. Follow-up data were available for 33 of the 60 patients. Treatment with locked versus nonlocked plates. Short Musculoskeletal Function Assessment (SMFA) questionnaire and the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale (AHS). Radiographic measurements on anteroposterior and lateral views for the quality of reduction and maintenance of alignment immediately postoperatively compared with the latest follow-up. There were no significant differences in the mechanism or injury pattern, average age of the patients, ratio of males to females, tourniquet time, operative time, interval to surgery, AHS, or SMFA scores. One of 15 fractures in the locked plate group lost reduction at the latest follow-up compared with 3 of 19 fractures in the nonlocked group. In this study, there seems to be no difference between the 2 constructs. Thus, one must question the routine use of locked plates in the treatment of high-energy pilon fractures. Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

  16. High-power terahertz optical pulse generation with a dual-wavelength harmonically mode-locked Yb:YAG laser

    Science.gov (United States)

    Zhuang, W. Z.; Chang, M. T.; Su, K. W.; Huang, K. F.; Chen, Y. F.

    2013-07-01

    We report on high-power terahertz optical pulse generation with a dual-wavelength harmonically mode-locked Yb:YAG laser. A semiconductor saturable absorber mirror is developed to achieve synchronously mode-locked operation at two spectral bands centered at 1031.67 and 1049.42 nm with a pulse duration of 1.54 ps and a pulse repetition rate of 80.3 GHz. With a diamond heat spreader to improve the heat removal efficiency, the average output power can be up to 1.1 W at an absorbed pump power of 5.18 W. The autocorrelation traces reveal that the mode-locked pulse is modulated with a beat frequency of 4.92 THz and displays a modulation depth to be greater than 80%.

  17. 59 fs mode-locked Yb:KGW oscillator pumped by a single-mode laser diode

    Science.gov (United States)

    Kowalczyk, M.; Sotor, J.; Abramski, K. M.

    2016-03-01

    In this letter we present a passively mode-locked Yb:KGW oscillator pumped by a low power single-mode laser diode. Contrary to high power operation, single-mode pumping enabled us to suppress parasitic thermal effects, while keeping the setup compact and its alignment straightforward. Undisturbed mode-locking (ML) stability was achieved without active cooling of the gain medium and the laser was entirely self-starting. Pulses 59 fs in duration were obtained in a semiconductor saturable absorber mirror (SESAM)-assisted Kerr-lens mode-locked regime. The corresponding spectrum was 20.2 nm broad at a central wavelength of 1036 nm approaching the performance limit of the crystal. To the best of our knowledge, these are the shortest pulses generated from a Yb:KGW laser.

  18. Sub-picosecond pulse and terahertz optical frequency comb generation by monolithically integrated linear mode-locked laser

    Science.gov (United States)

    Lo, Mu-Chieh; Guzmán, Robinson; Ali, Muhsin; Santos, Rui; Augustin, Luc; Carpintero, Guillermo

    2017-05-01

    We report on a record broad 3-dB bandwidth of 14 nm ( 1.8 THz around 1532 nm) optical frequency comb generated from a passively mode-locked quantum-well (QW) laser in the form of photonic integrated circuits through an InP generic photonic integration technology platform. This 21.5-GHz colliding-pulse mode-locked laser cavity is defined by two on-chip reflectors incorporating intracavity phase modulators followed by an out-of-cavity SOA as booster. Under certain operating conditions, an ultra-wide spectral bandwidth is achieved along with an autocorrelation trace confirming the mode locking nature exhibiting a pulse width of 0.35 ps. The beat note RF spectrum has a linewidth of sub-MHz and 35-dB SNR.

  19. Absolute spectroscopy near 7.8 {\\mu} m with a comb-locked extended-cavity quantum-cascade-laser

    KAUST Repository

    Lamperti, Marco

    2017-07-31

    We report the first experimental demonstration of frequency-locking of an extended-cavity quantum-cascade-laser (EC-QCL) to a near-infrared frequency comb. The locking scheme is applied to carry out absolute spectroscopy of N2O lines near 7.87 {\\\\mu}m with an accuracy of ~60 kHz. Thanks to a single mode operation over more than 100 cm^{-1}, the comb-locked EC-QCL shows great potential for the accurate retrieval of line center frequencies in a spectral region that is currently outside the reach of broadly tunable cw sources, either based on difference frequency generation or optical parametric oscillation. The approach described here can be straightforwardly extended up to 12 {\\\\mu}m, which is the current wavelength limit for commercial cw EC-QCLs.

  20. Canalizing Kauffman Networks: Nonergodicity and Its Effect on Their Critical Behavior

    OpenAIRE

    Moreira, André Auto; Nunes Amaral, Luís A.

    2005-01-01

    Boolean networks have been used to study numerous phenomena, including gene regulation, neural networks, social interactions, and biological evolution. Here, we propose a general method for determining the critical behavior of Boolean systems built from arbitrary ensembles of Boolean functions. In particular, we solve the critical condition for systems of units operating according to canalizing functions and present strong numerical evidence that our approach correctly predicts the phase tran...