Efficacy of Needle, Ultrasonic, and Endoactivator Irrigation and Photon-Induced Photoacoustic Streaming in Removing Calcium Hydroxide from the Main Canal and Isthmus: An In Vitro Micro-Computed Tomography and Scanning Electron Microscopy Study.

PubMed

Li, Dongxia; Jiang, Shan; Yin, Xingzhe; Chang, Jeffrey Wen Wei; Ke, Jie; Zhang, Chengfei

2015-06-01

The aim of this in vitro study was to use high-resolution micro-computed tomography (micro-CT) and scanning electron microscopy (SEM) to compare the efficacy of four irrigation techniques [needle, ultrasonic, EndoActivator, and photon-induced photoacoustic streaming (PIPS)] in removing calcium hydroxide (Ca[OH]2) from the root canal and isthmus of maxillary premolars. Twenty-four maxillary first premolars were selected based on the presence of isthmus regions on micro-CT scans. Root canals were instrumented with an F2 file using ProTaper rotary instruments and filled with Ca(OH)2 paste. Samples were stored at 37°C and 100% humidity for 1 week and randomly divided into four groups (n=6 each), according to irrigation technique. Samples were scanned with micro-CT before instrumentation, after Ca(OH)2 filling, and after irrigation. Ca(OH)2 reduction in the coronal, middle, and apical thirds and in the isthmus were assessed with three-dimensional image analysis. Next, specimens were split longitudinally, and canal walls were examined with SEM for Ca(OH)2 residues. Data were statistically evaluated with the Kruskal-Wallis and Mann-Whitney tests (p=0.05). The PIPS and ultrasonic groups showed greater Ca(OH)2 reduction in the apical third and higher cleanliness of the isthmus than the EndoActivator and needle irrigation groups (p<0.05). Ca(OH)2 residue scores in the PIPS and ultrasonic groups were significantly lower than those in the EndoActivator and needle groups in all regions of the root canals (p<0.05). There was no significant difference between PIPS and ultrasonic groups (p>0.05), or between EndoActivator and needle groups (p>0.05). PIPS and ultrasonic irrigation more effectively removed Ca(OH)2 from the main canal and isthmus in maxillary premolars than did EndoActivator or needle irrigation.

The effect of four different irrigation systems in the removal of a root canal sealer.

PubMed

Grischke, J; Müller-Heine, A; Hülsmann, M

2014-09-01

The aim of this study was to compare the efficiency of sonic, ultrasonic, and hydrodynamic devices in the removal of a root canal sealer from the surface and from simulated irregularities of root canals. Fifty-three root canals with two standardized grooves in the apical and coronal parts of longitudinally split roots were covered with AH Plus root canal sealer. Compared were the effects of (control) syringe irrigation, (1) CanalBrush, (2) passive ultrasonic irrigation, (3) EndoActivator, and (4) RinsEndo on the removal of the sealer. The specimens were divided into four groups (N = 12) and one control group (N = 5) via randomization. The amount of remaining sealer in the root canal irregularities was evaluated under a microscope using a 4-grade scoring system, whereas the remaining sealer on the root canal surface was evaluated with a 7-grade scoring system. Passive ultrasonic irrigation is more effective than the other tested irrigation systems or syringe irrigation in removing sealer from root canal walls (p < 0.01). None of the techniques had a significant effect on cleaning the lateral grooves. Within the limitations of this study protocol ultrasonic irrigation shows a superior effect on sealer removal from the root canal surface during endodontic retreatment. Cleaning of lateral grooves seems not to be possible with one of the techniques investigated. Incomplete removal of root canal sealer during re-treatment may cause treatment failure. Passive Ultrasonic irrigation seems to be the most effective system to remove sealer from a root canal.

Visualization of removal of trapped air from the apical region of the straight root canal models generating 2-phase intermittent counter flow during ultrasonically activated irrigation.

PubMed

Peeters, Harry Huiz; Iskandar, Bernard; Suardita, Ketut; Suharto, Djoko

2014-06-01

The purpose of this in vitro study was to obtain a better understanding of the mechanism of irrigant traveling apically and generating 2-phase intermittent counter flow in straight root canal models during activation of the irrigant by ultrasonic means in an endodontic procedure. A high-speed imaging system, with high temporal and spatial resolution (FastCam SA5; Photron, Tokyo, Japan) at a frame rate of 100,000 frames per second using a macro lens (60 mm, f/2.8; Nikon, Tokyo, Japan), was used to visualize, in glass models of root canals, an ultrasonically induced acoustic pressure wave in an EDTA solution environment. A 25-mm stainless steel noncutting file #20 driven by an ultrasonic device (P5 Newtron; Satelec Acteon, Mérignac, France) at power settings of 5 and 7 produced disturbances at the solution-air interface. We found that apically directed travel of the irrigant was caused by disruption of the surface tension at the solution-air interface. This disruption caused by ultrasonic activation energy displaced air in the form of bubbles from the apical region toward the solution. The apical movement of the solution may be attributed to ultrasonically induced wave generation at the solution-air interface, resulting in the removal of trapped air from the root canal and allowing the solution to travel apically in the opposite directions (via a 2-phase intermittent counter flow). Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Ultrasonic activation and chemical modification of photosensitizers enhances the effects of photodynamic therapy against Enterococcus faecalis root-canal isolates.

PubMed

Tennert, C; Drews, A M; Walther, V; Altenburger, M J; Karygianni, L; Wrbas, K T; Hellwig, E; Al-Ahmad, A

2015-06-01

The aim of this study was to evaluate the effect of photodynamic therapy (PDT) on Enterococcus faecalis biofilms in artificially infected root canals using modified photosensitizers and passive ultrasonic activation. Two hundred and seventy extracted human teeth with one root canal were instrumented utilizing ProTaper files, autoclaved, infected with E. faecalis T9 for 72 h and divided into different groups: irrigation with 3% sodium hypochlorite (NaOCl), 20% ethylenediaminetetraacetic acid (EDTA), or 20% citric acid, PDT without irrigation, PDT accompanied by irrigation with NaOCl, EDTA, or citric acid, PDT using an EDTA-based photosensitizer or a citric-acid-based photosensitizer and PDT with ultrasonic activation of the photosensitizer. A 15 mg/ml toluidine blue served as the photosensitizer, activated by a 100 mW LED light source. Sterile paper points were used for sampling the root canals and dentin chips were collected to assess the remaining contamination after treatment. Samples were cultured on blood agar plates and colony forming units were quantified. PDT alone achieved a reduction in E. faecalis counts by 92.7%, NaOCl irrigation alone and combined with PDT by 99.9%. The antibacterial effects increased by the combination of irrigation using EDTA or citric acid and PDT compared to irrigation alone. More than 99% of E. faecalis were killed using PDT with the modified photosensitizers and ultrasonic activation. NaOCl based disinfection achieved the highest antimicrobial effect. Using PDT with an EDTA-based or citric-acid-based phozosensitizer or activating the photosensitizer with ultrasound resulted in a significantly higher reduction in E. faecalis counts compared to conventional PDT. Copyright © 2015 Elsevier B.V. All rights reserved.

Review of ultrasonic irrigation in endodontics: increasing action of irrigating solutions

PubMed Central

Mozo, Sandra; Llena, Carmen

2012-01-01

Introduction: Effective irrigant delivery and agitation are prerequisites for successful endodontic treatment. Ultrasonic irrigation can be performed with or without simultaneous ultrasonic instrumentation. Existing literature reveals that ultrasonic irrigation may have a very positive effect on chemical, biological and physical debridement of the root canal system as investigated in many in vitro studies. Objective: The purpose of this review article was to summarize and discuss the available information concerning ultrasonic irrigation in endodontics. Methods: This article presents an overview of ultrasonic irrigation methods and their debridement efficacy. In this paper the relevant literature on passive ultrasonic irrigation is reviewed. Information from original scientific papers or reviews listed in MEDLINE and Cochrane were included in the review. Results: The use of ultrasound in the irrigation procedure results in improved canal cleanliness, better irrigant transfer to the canal system, soft tissue debridement, and removal of smear layer and bacteria. There are many in vitro studies, but there is a need to standardize protocols, and correlate the clinical efficacy of ultrasonic devices with improved treatment outcomes. Understanding the basis of ultrasonic irrigation is fundamental for clinicians and researchers to improve the design and use of ultrasonic irrigation. Key words:Ultrasonic irrigation, ultrasound, smear layer, endodontics. PMID:22143738

Bacteriological comparison of ultrasonic and hand instrumentation of root canals in dogs.

PubMed

DeNunzio, M S; Hicks, M L; Pelleu, G B; Kingman, A; Sauber, J J

1989-07-01

This study compared the effectiveness of hand and ultrasonic instrumentation for removing a standardized inoculum of pigmented Serratia marcescens from the root canal system of premolars in dogs. Forty-four premolars from nine beagle dogs were divided into two experimental groups of 20 and 24 teeth, respectively. The experimental teeth were inoculated with approximately 10 colony-forming units of S. marcescens. After the bacterial were allowed to colonize for 1 wk, the experimental teeth were instrumented with either hand instruments or the Cavi-Endo device. The teeth were extracted, crushed, and assayed for recoverable colony-forming units of S. marcescens. Statistical comparisons of the ratio of inoculated to recovered colony-forming untis were made. The results indicated that the difference between the positive controls and the experimental groups was significant. There was no significant difference between the two instrumentation groups.

Unified Ultrasonic/Eddy-Current Data Acquisition

NASA Technical Reports Server (NTRS)

Chern, E. James; Butler, David W.

1993-01-01

Imaging station for detecting cracks and flaws in solid materials developed combining both ultrasonic C-scan and eddy-current imaging. Incorporation of both techniques into one system eliminates duplication of computers and of mechanical scanners; unifies acquisition, processing, and storage of data; reduces setup time for repetitious ultrasonic and eddy-current scans; and increases efficiency of system. Same mechanical scanner used to maneuver either ultrasonic or eddy-current probe over specimen and acquire point-by-point data. For ultrasonic scanning, probe linked to ultrasonic pulser/receiver circuit card, while, for eddy-current imaging, probe linked to impedance-analyzer circuit card. Both ultrasonic and eddy-current imaging subsystems share same desktop-computer controller, containing dedicated plug-in circuit boards for each.

Investigations into in situ Enterococcus faecalis biofilm removal by passive and active sodium hypochlorite irrigation delivered into the lateral canal of a simulated root canal model.

PubMed

Mohmmed, S A; Vianna, M E; Penny, M R; Hilton, S T; Mordan, N J; Knowles, J C

2018-06-01

To investigate in situ Enterococcus faecalis biofilm removal from the lateral canal of a simulated root canal system using passive or active irrigation protocols. Root canal models (n = 43) were manufactured from transparent resin materials using 3D printing. Each canal was created with an 18 mm length, apical size 30, a .06 taper and a lateral canal of 3 mm length, with 0.3 mm diameter. Biofilms were grown in the lateral canal and apical 3 mm of the main canal for 10 days. Three models from each group were examined for residual biofilm using SEM. The other forty models were divided into four groups (n = 10). The models were observed under a fluorescence microscope. Following 60 s of 9 mL of 2.5% NaOCl irrigation using syringe and needle, the irrigant was either left stagnant in the canal or activated using gutta-percha, sonic or ultrasonic methods for 30 s. Images were then captured every second using an external camera. The residual biofilm percentages were measured using image analysis software. The data were analysed using generalized linear mixed models. A significance level of 0.05 was used throughout. The greatest level of biofilm removal was obtained with ultrasonic agitation (66.76%) followed by sonic (45.49%), manual agitation (43.97%) and passive irrigation groups (38.67%), respectively. The differences were significant between the residual biofilm in the passive irrigation and both sonic and ultrasonic groups (P = 0.001). Agitation resulted in better penetration of 2.5% NaOCl into the lateral canal of an artificial root canal model. Ultrasonic agitation of NaOCl improved the removal of biofilm. © 2017 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Synergistic effect of microbubble emulsion and sonic or ultrasonic agitation on endodontic biofilm in vitro.

PubMed

Halford, Andrew; Ohl, Claus-Dieter; Azarpazhooh, Amir; Basrani, Bettina; Friedman, Shimon; Kishen, Anil

2012-11-01

Irrigation dynamics and antibacterial activity determine the efficacy of root canal disinfection. Sonic or ultrasonic agitation of irrigants is expected to improve irrigation dynamics. This study examined the effects of microbubble emulsion (ME) combined with sonic or ultrasonic agitation on irrigation dynamics and reduction of biofilm bacteria within root canal models. Two experiments were conducted. First, high-speed imaging was used to characterize the bubble dynamics generated in ME by sonic or ultrasonic agitation within canals of polymer tooth models. Second, 5.25% NaOCl irrigation or ME was sonically or ultrasonically agitated in canals of extracted teeth with 7-day-grown Enterococcus faecalis biofilms. Dentinal shavings from canal walls were sampled at 1 mm and 3 mm from the apical terminus, and colony-forming units (CFUs) were enumerated. Mean log CFU/mL values were analyzed with analysis of variance and post hoc tests. High-speed imaging demonstrated strongly oscillating and vaporizing bubbles generated within ME during ultrasonic but not sonic agitation. Compared with CFU counts in controls, NaOCl-sonic and NaOCl-ultrasonic yielded significantly lower counts (P < .05) at both measurement levels. ME-sonic yielded significantly lower counts (P = .002) at 3 mm, whereas ME-ultrasonic yielded highly significantly lower counts (P = .000) at both measurement levels. At 3 mm, ME-ultrasonic yielded significantly lower CFU counts (P = .000) than ME-sonic, NaOCl-sonic, and NaOCl-ultrasonic. Enhanced bubble dynamics and reduced E. faecalis biofilm bacteria beyond the level achieved by sonic or ultrasonic agitation of NaOCl suggested a synergistic effect of ME combined with ultrasonic agitation. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

The Effect of Final Rinse Agitation with Ultrasonic or 808 nm Diode Laser on Coronal Microleakage of Root-canal Treated Teeth.

PubMed

Ramazani, Mohsen; Asnaashari, Mohammad; Ahmadi, Roghayyeh; Zarenejad, Nafiseh; Rafie, Alireza; Yazadani Charati, Jamshid

2018-01-01

This in vitro study aimed at comparing the effect of agitating the final irrigant solutions of root canal by ultrasonic or using 808 nm Diode laser on the apical seal of canal. A total of 90 extracted human maxillary central incisors were prepared up to size #45 and were randomly assigned to 4 experimental groups ( n =20) and two control groups ( n =5) respectively, as follows: I ): 3 mL of 5.25% NaOCl was agitated as final irrigant solution with ultrasonic for 30 sec. The ultrasonic tip was 1 mm shorter than the working length, II ): 3 mL of 5.25% NaOCl was agitated as final irrigant with 808 nm Diode laser for 30 sec. Fiber tip, placed in 1 mm shorter from working length was spirally moved coronally, III ): 3 mL of 17% EDTA was agitated as final irrigant with 808 nm Diode laser for 30 sec and was applied similar to group II, IV ): 3 mL of 17% EDTA was stimulated as final irrigant with ultrasonic for 30 sec and was applied similar to I. Apical seal was assessed by Dual Chamber technique using Bovine Serum Albumin protein. Kruskal-Wallis and Mann Whitney tests were used with significance level lower than 0.05% for statistical analysis. The average leakage in the negative control, positive control, and groups I, II, III, IV were: 0.00, 13.5±5.1, 1.72±2.9, 5.12±5.6, 3.36±3.7, 2.4±4.2, respectively. Statistical analysis showed significant difference between groups ( P <0.05). There was a significant difference between groups 1 and 2 in terms of protein leakage . Agitating 5.25% sodium hypochlorite solution as the final irrigant with ultrasonic is more effective in apical leakage reduction compared to other groups.

Effect of Passive Ultrasonic Irrigation on Enterococcus faecalis from Root Canals: An Ex Vivo Study.

PubMed

Guerreiro-Tanomaru, Juliane Maria; Chávez-Andrade, Gisselle Moraima; de Faria-Júnior, Norberto Batista; Watanabe, Evandro; Tanomaru-Filho, Mário

2015-01-01

Endodontic irrigation aims to clean and disinfect the root canal system. Passive ultrasonic irrigation (PUI) is based on the use of an ultrasound-activated instrument into the root canal filled with irrigant. The aim of this study was to evaluate, ex vivo, the effectiveness of PUI in eliminating Enterococcus faecalis from root canals. Seventy-five extracted human single-root teeth were used. After root canal preparation, specimens were inoculated with E. faecalis and incubated at 37 °C for 21 days. Specimens were distributed into five groups (n=15), according to the irrigation method: PUI + saline solution (PUI/SS); PUI + 1% NaOCl (PUI/NaOCl); conventional needle irrigation (CNI) + saline solution (CNI/SS); CNI + 1% NaOCl (CNI/NaOCl); No irrigation (control). Microbiological samples were collected at three time points: initial (21 days after inoculation), post-irrigation (immediately after irrigation), and final (7 days after irrigation). Data were obtained in CFU mL-1 and subjected to analysis by ANOVA and Tukey's tests at 5% significance level. The post-irrigation samples did not demonstrate statistical difference between PUI/SS and CNI/SS nor between PUI/NaOCl and CNI/NaOCl (p>0.05), but PUI/NaOCl and CNI/NaOCl had lower CFU mL-1 number than the other groups (p>0.05). Statistically significant difference was observed between the initial and post-irrigation samples and between the post-irrigation and final samples (p<0.05) in all groups, except in the control. The final samples of all groups presented bacterial counts similar to the initial samples. PUI or CNI with 1% NaOCl contribute to disinfection, but are unable to eradicate E. faecalis from the root canal system.

Comparative evaluation of calcium hypochlorite and sodium hypochlorite associated with passive ultrasonic irrigation on antimicrobial activity of a root canal system infected with Enterococcus faecalis: an in vitro study.

PubMed

de Almeida, Ana Paula; Souza, Matheus Albino; Miyagaki, Daniela Cristina; Dal Bello, Yuri; Cecchin, Doglas; Farina, Ana Paula

2014-12-01

The purpose of this study was to compare in vitro the effectiveness of calcium hypochlorite (Ca[OCl]2) and sodium hypochlorite (NaOCl) associated with passive ultrasonic irrigation in root canals of bovine teeth infected with Enterococcus faecalis. The root canals of 60 single-rooted bovine extracted teeth were enlarged up to a file 45, autoclaved, inoculated with Enterococcus faecalis, and incubated for 30 days. The samples were divided into 6 groups (n = 10) according to the protocol for decontamination: G1: no treatment; G2: distilled water; G3: 2.5% NaOCl; G4: 2.5% Ca(OCl)2; G5: 2.5% NaOCl with ultrasonic activation; and G6: 2.5% Ca(OCl)2 with ultrasonic activation (US). Microbiological testing (colony-forming unit [CFU] counting) was performed to evaluate and show, respectively, the effectiveness of the proposed treatments. Data were subjected to 1-way analysis of variance followed by the post hoc Tukey test (α = 0.05). Groups 1 and 2 showed the highest mean contamination (3.26 log10 CFU/mL and 2.69 log10 CFU/mL, respectively), which was statistically different from all other groups (P < .05). Group 6 (Ca[OCl]2 + US) showed the lowest mean contamination (1.00 log10 CFU/mL), with no statistically significant difference found in groups 3 (NaOCl), 4 (Ca[OCl]2), and 5 (NaOCl + US) (P < .05). Ca(OCl)2 as well as passive ultrasonic irrigation can aid in chemomechanical preparation, contributing in a significant way to the reduction of microbial content during root canal treatment. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Cavitation measurement during sonic and ultrasonic activated irrigation.

PubMed

Macedo, Ricardo; Verhaagen, Bram; Rivas, David Fernandez; Versluis, Michel; Wesselink, Paul; van der Sluis, Luc

2014-04-01

The aims of this study were to quantify and to visualize the possible occurrence of transient cavitation (bubble formation and implosion) during sonic and ultrasonic (UAI) activated irrigation. The amount of cavitation generated around several endodontic instruments was measured by sonochemiluminescence dosimetry inside 4 root canal models of human dimensions and varying complexity. Furthermore, the spatial distribution of the sonochemiluminescence in the root canal was visualized with long-exposure photography. Instrument oscillation frequency, ultrasonic power, and file taper influenced the occurrence and amount of cavitation. In UAI, cavitation was distributed between the file and the wall extending beyond the file and inside lateral canals/isthmuses. In sonic activated irrigation, no cavitation was detected. Cavitation was shown to occur in UAI at clinically relevant ultrasonic power settings in both straight and curved canals but not around sonically oscillating instruments, driven at their highest frequency. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

[Root canal treatment of mandibular first premolar with 4 root canals: a case report].

PubMed

Liu, Xin-yang; Zhan, Fu-Liang

2015-10-01

The mandibular first premolar can be considered one of the most challenging teeth to treat, due to the complexity of its root canal morphology and increased incidence of multiple canals. A case of endodontic treatment of a mandibular first premolar exhibiting a total of 4 distinct root canals and 4 apical foramina was described. Anatomic variation of root canal morphology should be considered in endodontic treatment to ensure a favorable healing outcome, and its identification could be enhanced by careful examination using a dental operating microscope. Obturation of root canals using a warm vertical compaction technique with a highly-radiopaque root canal sealer, such as AH Plus, after careful ultrasonic activated irrigation might allow the flow of sealer into the narrowed but unprepared part of the canal, thereby facilitating optimum chemo-mechanical debridement of the root canal system.

Ultrasonics in Dentistry

NASA Astrophysics Data System (ADS)

Walmsley, A. D.

Ultrasonic instruments have been used in dentistry since the 1950's. Initially they were used to cut teeth but very quickly they became established as an ultrasonic scaler which was used to remove deposits from the hard tissues of the tooth. This enabled the soft tissues around the tooth to return to health. The ultrasonic vibrations are generated in a thin metal probe and it is the working tip that is the active component of the instrument. Scanning laser vibrometry has shown that there is much variability in their movement which is related to the shape and cross sectional shape of the probe. The working instrument will also generate cavitation and microstreaming in the associated cooling water. This can be mapped out along the length of the instrument indicating which are the active areas. Ultrasonics has also found use for cleaning often inaccessible or different surfaces including root canal treatment and dental titanium implants. The use of ultrasonics to cut bone during different surgical techniques shows considerable promise. More research is indicated to determine how to maximize the efficiency of such instruments so that they are more clinically effective.

An in vitro evaluation of the degree of pulp tissue dissolution through different root canal irrigation protocols.

PubMed

Amato, Massimo; Pantaleo, Giuseppe; Abtellatif, Dina; Blasi, Andrea; Gagliani, Massimo; Iandolo, Alfredo

2018-01-01

The aim of this study is to evaluate in vitro , using artificial lateral canals, the rate of dissolution of the pulp tissue through different protocols of canal irrigation. One hundred artificial canals provided with lateral canals have been used. Each lateral canal was filled with pulp tissue and calibrated to 0.002 mg. All canals were irrigated using five different protocols. Five groups have been used for the experiment: Group A, distilled water (control); Group B, preheated NaOCl; Group C, NaOCl heated inside the canal; Group D, NaOCl ultrasonically activated; and Group E, NaOCl heated inside the canal with ultrasonic activation. All samples were weighed through professional microbalance in three different phases: before insertion of the pulp tissue into the lateral canal, after insertion of the pulp tissue and, finally, after different protocols of irrigation. A statistical analysis with Kruskal-Wallis test and Mann-Whitney test was performed. The partial dissolution of the pulp tissue inside the artificial lateral canal occurs only using the protocol with NaOCl heated inside the canal with ultrasonic activation. Other irrigation protocols are not able to dissolve the pulp tissue. The main objective of endodontic therapy is the removal of damaged tissues and bacteria. Modern literature highlights that it is impossible to remove all the pulp tissues and bacteria from the whole endodontic space. Hence, to achieve excellence and get positive results in the short and long term, it is necessary to use techniques and technologies that may increase the degree of root canal detersion.

Eddy current X-Y scanner system

NASA Technical Reports Server (NTRS)

Kurtz, G. W.

1983-01-01

The Nondestructive Evaluation Branch of the Materials and Processes Laboratory became aware of a need for a miniature, portable X-Y scanner capable of performing eddy current or other nondestructive testing scanning operations such as ultrasonic, or small areas of flat plate. The technical description and operational theory of the X-Y scanner system designed and built to fulfill this need are covered. The scanner was given limited testing and performs according to its design intent, which is to scan flat plate areas of approximately 412 sq cm (64 sq in) during each complete cycle of scanning.

Mandibular first premolar with four canals.

PubMed

Du, Yi; Lee, Angeline H C; Zhang, Chengfei

2013-02-01

A case of endodontic treatment of a mandibular first premolar exhibiting a total of four distinct root canals and four apical foramina is described. This occurrence in mandibular first premolar has rarely been reported in the endodontic literature. Endodontic treatment that considers the anatomic variation of root canal morphology is important to ensure a favorable healing outcome, and its identification could be enhanced by careful examination using a dental operating microscope. Obturation of root canals using a warm vertical compaction technique with a highly-radiopaque root canal sealer, such as AH Plus, after careful ultrasonic activated irrigation with ethylenediaminetetraacetic acid might allow the flow of sealer into the narrowed but unprepared part of the canal. This offers valuable adjuncts for the successful negotiation of calcified main canals, thereby facilitating optimum chemo-mechanical debridement of the root canal system. © 2013 Blackwell Publishing Asia Pty Ltd.

Two-dimensional scanner apparatus. [flaw detector in small flat plates

NASA Technical Reports Server (NTRS)

Kurtz, G. W.; Bankston, B. F. (Inventor)

1984-01-01

An X-Y scanner utilizes an eddy current or ultrasonic current test probe to detect surface defects in small flat plates and the like. The apparatus includes a scanner which travels on a pair of slide tubes in the X-direction. The scanner, carried on a carriage which slides in the Y-direction, is driven by a helix shaft with a closed-loop helix groove in which a follower pin carried by scanner rides. The carriage is moved incrementally in the Y-direction upon the completion of travel of the scanner back and forth in the X-direction by means of an indexing actuator and an indexing gear. The actuator is in the form of a ratchet which engages ratchet gear upon return of the scanner to the indexing position. The indexing gear is rotated a predetermined increment along a crack gear to move carriage incrementally in the Y-direction. Thus, simplified highly responsive mechanical motion may be had in a small lightweight portable unit for accurate scanning of small area.

Bulk-wave ultrasonic propagation imagers

NASA Astrophysics Data System (ADS)

Abbas, Syed Haider; Lee, Jung-Ryul

2018-03-01

Laser-based ultrasound systems are described that utilize the ultrasonic bulk-wave sensing to detect the damages and flaws in the aerospace structures. These systems apply pulse-echo or through transmission methods to detect longitudinal through-the-thickness bulk-waves. These thermoelastic waves are generated using Q-switched laser and non-contact sensing is performed using a laser Doppler vibrometer (LDV). Laser-based raster scanning is performed by either twoaxis translation stage for linear-scanning or galvanometer-based laser mirror scanner for angular-scanning. In all ultrasonic propagation imagers, the ultrasonic data is captured and processed in real-time and the ultrasonic propagation can be visualized during scanning. The scanning speed can go up to 1.8 kHz for two-axis linear translation stage based B-UPIs and 10 kHz for galvanometer-based laser mirror scanners. In contrast with the other available ultrasound systems, these systems have the advantage of high-speed, non-contact, real-time, and non-destructive inspection. In this paper, the description of all bulk-wave ultrasonic imagers (B-UPIs) are presented and their advantages are discussed. Experiments are performed with these system on various structures to proof the integrity of their results. The C-scan results produced from non-dispersive, through-the-thickness, bulk-wave detection show good agreement in detection of structural variances and damage location in all inspected structures. These results show that bulk-wave UPIs can be used for in-situ NDE of engineering structures.

Removal efficiency of calcium hydroxide dressing from the root canal without chemically active adjuvant.

PubMed

Maalouf, Lara; Zogheib, Carla; Naaman, Alfred

2013-03-01

Compare the efficiency in removing two calcium hydroxide [Ca(OH)2] preparations from root canal and apical third using single use syringe, ultrasonics and RinsEndo((®)) with saline solution. One hundred and eighty human singlerooted teeth were instrumented using ProTaper((®)) rotary system, divided into two groups according to Ca(OH)2 filling. A: Powder mixed with water, B: Pulpdent((®)). Each group was divided into three subgroups for the irrigation: A1, B1: Single use syringe; A2, B2: Ultrasonics; A3, B3: RinsEndo((®)). Teeth were split longitudinally, photographed and imported into Adobe Photoshop. The percentage ratios of Ca(OH)2 remaining in the canal and in the apical third were calculated. Data were statistically analyzed using 'ANOVA two-way' and 'univariate tests'. (a) Remnants of medicament were found in all teeth, (b) no statistically significant difference in the elimination of both Ca(OH)2 from the entire canal (p = 0.436), however, mixed powder was better eliminated from the apical third (p = 0.005), (c) no statistically significant difference among the irrigation techniques in the whole canal (p = 0.608), though, RinsEndo((®)) and ultrasonics were the most effective in cleaning the apical third (p = 0.032) when mixed powder was used. None of the techniques removed completely Ca(OH)2 from the canal. In the apical third, RinsEndo((®)) and ultrasonics were the most effective when mixed powder was used. Ca(OH)2, the most commonly used intracanal dressing, should be completely eliminated before the obturation to assure a good endodontic sealing. Based on the results of this study, RinsEndo((®)) and ultrasonics were the most effective in removal of Ca(OH)2 especially the powder mixed with water presentation.

Broken instrument retrieval with indirect ultrasonics in a primary molar.

PubMed

Pk, Musale; Sc, Kataria; As, Soni

2016-02-01

The separation of a file during pulpectomy is a rare incident in primary teeth due to inherently wider and relatively straighter root canals. A broken instrument hinders the clinician from optimal preparation and obturation of the root canal system invariably leading to failure, although in such teeth, an extraction followed by suitable space maintenance is considered as the treatment of choice. This case report demonstrates successful nonsurgical retrieval of a separated H file fragment in 84. A 7-year-old girl was referred to the Department of Paedodontics and Preventive Dentistry for endodontic management of a primary tooth 84 with a dento-alveolar abscess. Her medical history was noncontributory. After diagnosing a broken H file in the mesio-lingual canal, the tooth was endodontically treated in two appointments. At the first session, a broken file was successfully retrieved after using low intensity ultrasonic vibrations through a DG 16 endodontic explorer viewed under an operating microscope. After abscess resolution, Vitapex root canal obturation with a preformed metal crown cementation was completed at a second session. The patient was recalled at 3, 6, 12 and 15 month interval and reported to be clinically asymptomatic and radiographically with complete furcal healing. Integration of microscopes and ultrasonics in paediatric dental practice has made it possible to save such teeth with a successful outcome. Favourable location of the separated file, relatively straighter root canal system and patient cooperation resulted in successful nonsurgical management in this case.

Micro-computed tomography evaluation of the removal of calcium hydroxide medicament from C-shaped root canals of mandibular second molars.

PubMed

Ma, J Z; Shen, Y; Al-Ashaw, A J; Khaleel, H Y; Yang, Y; Wang, Z J; Peng, B; Haapasalo, M

2015-04-01

To use micro-computed tomography (μ-CT) to evaluate the amount of calcium hydroxide [Ca(OH)2 ] remaining in the C-shaped root canals of mandibular second molars after attempting to remove it with passive ultrasonic and sonic irrigation. Thirty mandibular second molars, 15 in C1 and 15 in C2 configurations as first identified by μ-CT, were divided into three groups (five C1 and five C2 in each group) for the three irrigation methods. All teeth were prepared to ProTaper Universal F2 and filled with Ca(OH)2 paste. The Ca(OH)2 was removed with F2 files and irrigation without agitation or with agitation using either EndoActivator or ultrasonics. μ-CT was used to measure the initial amount of Ca(OH)2 present. After removal of Ca(OH)2, μ-CT imaging was used to assess the percentage of volume of residual Ca(OH)2 in the canal. Data were analysed using one-way anova test. There was no significant difference in the mean volume of the root canal systems after instrumentation amongst the three groups. The three irrigation techniques left 2-17% of Ca(OH)2 in the root canals after removal. The mean volume of the remaining Ca(OH)2 was higher in the group without agitation than in the groups with sonic or ultrasonic agitation (P < 0.05). In the apical third, 68% of the canal space remained occupied by Ca(OH)2 when no agitation was used, whereas 28% and 31% remained filled by Ca(OH)2 in the EndoActivator and ultrasonic groups, respectively. There was no significant difference in the amount of residual Ca(OH)2 between the EndoActivator and ultrasonic groups. The proportion of remaining Ca(OH)2 in the apical canals was higher than in the middle and coronal canals in all groups (P < 0.05). A considerable proportion of the apical canal space remained filled with Ca(OH)2 in the C-shaped root canals after instrumentation and conventional needle irrigation. Although combining rotary instrumentation and irrigation with sonic or ultrasonic agitation reduced the amount of residual Ca

Airborne ultrasonic inspection in carbon/carbon composite materials

NASA Astrophysics Data System (ADS)

Yang, In-Young; Kim, Young-Hun; Park, Je-Woong; Hsu, David K.; Song, Song-Jin; Cho, Hyun-Jun; Kim, Sun-Kyu; Im, Kwang-Hee

2007-07-01

In this work, a carbon/carbon (C/C) composite material was nondestructively characterized with non-contact ultrasonic methods using automated acquisition scanner as well as contact ultrasonic measurement because (C/C) composite materials have obvious high price over conventional materials. Because of permeation of coupling medium such as water, it is desirable to perform contact-less nondestructive evaluation to assess material properties and part homogeneity. Also through transmission mode was performed because of the main limitation for air-coupled transducers, which is the acoustic impedance mismatch between most materials and air. Especially ultrasonic images and velocities for C/C composite disk brake was measured and found to be consistent to some degree with the non-contact and contact ultrasonic measurement methods. Low frequency through-transmission scans based on both amplitude and time-of-flight of the ultrasonic pulse were used for mapping out the material property inhomogeneity. Measured results were compared with those obtained by the motorized system with using dry-coupling ultrasonics and through transmission method in immersion. Finally, results using a proposed peak-delay measurement method well corresponded to ultrasonic velocities of the pulse overlap method.

Ultrasonic irrigation of a maxillary lateral incisor with perforation of the apical third of the root.

PubMed

Tsurumachi, Tamotsu; Takita, Toshiya; Hashimoto, Kazuhiro; Katoh, Takeshi; Ogiso, Bunnai

2010-12-01

We describe the successful use of a combination of nonsurgical root canal treatment and ultrasonic irrigation for collaborative management of a maxillary left lateral incisor with perforation of the apical third of the root. During the endodontic treatment procedure, the ultrasonically activated tip was used for intracanal irrigation. The area of perforation in the apical third of the root and the main root canal space were obturated with gutta-percha and root canal sealer, using a lateral condensation method. A follow-up clinical and radiographic examination at 5 years after treatment showed an asymptomatic tooth with excellent osseous healing.

Thermal injury through intraradicular heat transfer using ultrasonic devices: precautions and practical preventive strategies.

PubMed

Gluskin, Alan H; Ruddle, Clifford J; Zinman, Edwin J

2005-09-01

The use of ultrasonic energy is a highly efficient method of removing obstructions and cements within the root canal space when re-treatment or rehabilitation of that ultrasonic energy dislodges and removes cemented objects from the bonded interface of the canal wall. When using this method, there is less potential for structural loss or root damage and significantly less operator stress than when using other methods. There is little evidence in published research of the considerable heat transfer that occurs during use of ultrasonic devices to remove posts, pastes and separated instruments in teeth. The authors present three cases of patients who experienced serious burn injuries during application of ultrasonic energy for restorative dentistry. The authors also offer techniques and strategies for safe and effective use of ultrasonic devices. On the basis of the best available evidence, the authors recommend strategies to provide safe and effective therapy while using ultrasonic devices in intraradicular obstruction removal. The intent of the suggested protocols is to provide advanced and sophisticated therapies in a safe and regulated manner with patient safety as an overriding priority.

Root canal debridement: an online study guide.

PubMed

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.

Root canal penetration of a sodium hypochlorite mixture using sonic or ultrasonic activation.

PubMed

Sáinz-Pardo, Marta; Estevez, Roberto; Pablo, Óliver Valencia de; Rossi-Fedele, Giampiero; Cisneros, Rafael

2014-01-01

The purpose of this ex vivo study was to determine, in "open" and "closed" systems, whether the design has an influence on the penetration length of sodium hypochlorite mixed with a radiopaque contrast medium, measured in millimeters, when delivered using positive pressure (PP) and using sonic (SI) or passive ultrasonic (PUI) activation. Sixty single-rooted teeth were divided into two groups: open and closed systems (n=30). Root canal shaping was performed to a working length of 17 mm. The samples were divided into three sub-groups (n=10) according to irrigant delivery and activation: PP, and SI or PUI activation. By using radiographs, penetration length was measured, and vapor lock was assessed. For the closed group, the penetration distance means were: PP 15.715 (±0.898) mm, SI 16.299 (±0.738) mm and PUI 16.813 (±0.465) mm, with vapor lock occurring in 53.3% of the specimens. In the open group, penetration to 17 mm occurred in 97.6% of the samples, and no vapor lock occurred. Irrigant penetration and distribution evaluation using open and closed systems provide significantly different results. For closed systems, PUI is the most effective in delivering the irrigant to working length, followed by SI.

Detection and imaging of corrosion around wing skin fasteners using the dripless bubbler ultrasonic scanner

NASA Astrophysics Data System (ADS)

Hsu, David K.; Barnard, Daniel J.

1998-03-01

The galvanic action between steel fasteners and aluminum wing skins of aircraft often leads to hidden exfoliation corrosion around the countersink surface of the fastener heads. To detect and evaluate the severity of such corrosion defects, the Dripless Bubbler ultrasonic scanner was applied. This technique uses a focused beam of high frequency ultrasound in a closed-cycle, water-coupled scan of wing skin test panels containing corroded and uncorroded fasteners. With full waveform acquisition, not only the lateral extent but also the depth profile of the corrosions around the fastener heads were mapped out, subject to shadowing of defects at different depth. The technique is capable of providing quantitative assessment of the severity of the corrosion. In tests conducted to evaluate different techniques, the Dripless Bubbler has shown high probability of detection and low false call rate. The presence of paint on the surface did not degrade the performance of the technique. In addition, the Dripless Bubbler was also used on wing skin panels containing repair 'blend-out' regions that had 0.020' to 0.100' of metal removed from the surface by grinding. Corrosions around fasteners in the blend-out regions were also detected.

Clinical efficacy of EDTA ultrasonic activation in the reduction of endotoxins and cultivable bacteria.

PubMed

Herrera, D R; Martinho, F C; de-Jesus-Soares, A; Zaia, A A; Ferraz, C C R; Almeida, J F A; Gomes, B P F A

2017-10-01

This clinical study was conducted to investigate the influence of 17% ethylenediaminetetraacetic acid (EDTA) ultrasonic activation after chemomechanical preparation (CMP) on eliminating/reducing oral bacterial lipopolysaccharides (known as endotoxins) and cultivable bacteria in teeth with pulp necrosis and apical periodontitis. Samples were taken from 24 root canals at several clinical periods: S1 - before CMP; S2 - after CMP; S3 - after EDTA: G1 - with ultrasonic activation (n = 12) and G2 - without ultrasonic activation (n = 12). Root canals were instrumented using Mtwo rotary files. Culture techniques were used to determine the number of colony-forming units (CFU). Limulus amebocyte lysate (LAL) was used to measure endotoxin levels. Friedman's and Wilcoxon signed-rank tests were used to compare the amount of bacteria and endotoxin levels in each period (P < 0.05). Endotoxins and cultivable bacteria were recovered in 100% of the initial samples (S1). CMP was effective in reducing endotoxins and bacterial load (all with P < 0.05). Higher values of endotoxin reduction were achieved with EDTA ultrasonic activation [G1, 0.02 EU mL -1 (range 0.01-0.75)] compared with the no activation group [G2, 1.13 EU mL -1 (range 0.01-8.34)] (P < 0.05). Regarding bacterial reduction, no statistically significant difference was found in S3, regardless of the group (G1, G2, P > 0.05). Chemomechanical preparation was effective in reducing bacteria and endotoxins, but could not completely eliminate them. The ultrasonic activation of EDTA was effective in further reducing endotoxin levels in the root canals of teeth with pulp necrosis and apical periodontitis. © 2016 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Comparative antibacterial efficacies of hydrodynamic and ultrasonic irrigation systems in vitro.

PubMed

Cachovan, Georg; Schiffner, Ulrich; Altenhof, Saskia; Guentsch, Arndt; Pfister, Wolfgang; Eick, Sigrun

2013-09-01

To ensure root canal treatment success, endodontic microbiota should be efficiently reduced. The in vitro bactericidal effects of a hydrodynamic system and a passive ultrasonic irrigation system were compared. Single-rooted extracted teeth (n = 250) were contaminated with suspensions of Enterococcus faecalis ATCC 29212, mixed aerobic cultures, or mixed anaerobic cultures. First, the antibacterial effects of the hydrodynamic system (RinsEndo), a passive ultrasonic irrigation system (Piezo smart), and manual rinsing with 0.9% NaCl (the control) were compared. Colony-forming units were counted. Second, the 2 systems were used with 1.5% sodium hypochlorite (NaOCl) alone or NaOCl + 0.2% chlorhexidine (CHX). The colony-forming units in the treated and untreated roots were determined during a period of 5 days. Both irrigation systems reduced bacterial numbers more effectively than manual rinsing (P < .001). With NaCl, ultrasonic activated irrigation reduced bacterial counts significantly better than hydrodynamic irrigation (P = .042). The NaOCl + CHX combination was more effective than NaOCl alone for both systems (P < .001), but hydrodynamic irrigation was more effective with NaOCl + CHX than the passive ultrasonic irrigation system. Both irrigation systems, when combined with NaOCl + CHX, removed bacteria from root canals. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Static, Dynamic, and Fatigue Analysis of the Mechanical System of Ultrasonic Scanner for Inservice Inspection of Research Reactors

NASA Astrophysics Data System (ADS)

Awwaluddin, Muhammad; Kristedjo, K.; Handono, Khairul; Ahmad, H.

2018-02-01

This analysis is conducted to determine the effects of static and dynamic loads of the structure of mechanical system of Ultrasonic Scanner i.e., arm, column, and connection systems for inservice inspection of research reactors. The analysis is performed using the finite element method with 520 N static load. The correction factor of dynamic loads used is the Gerber mean stress correction (stress life). The results of the analysis show that the value of maximum equivalent von Mises stress is 1.3698E8 Pa for static loading and value of the maximum equivalent alternating stress is 1.4758E7 Pa for dynamic loading. These values are below the upper limit allowed according to ASTM A240 standards i.e. 2.05E8 Pa. The result analysis of fatigue life cycle are at least 1E6 cycle, so it can be concluded that the structure is in the high life cycle category.

Optodynamic Phenomena During Laser-Activated Irrigation Within Root Canals

NASA Astrophysics Data System (ADS)

Lukač, Nejc; Gregorčič, Peter; Jezeršek, Matija

2016-07-01

Laser-activated irrigation is a powerful endodontic treatment for smear layer, bacteria, and debris removal from the root canal. In this study, we use shadow photography and the laser-beam-transmission probe to examine the dynamics of laser-induced vapor bubbles inside a root canal model and compare ultrasonic needle irrigation to the laser method. Results confirm important phenomenological differences in the two endodontic methods with the laser method resulting in much deeper irrigation. Observations of simulated debris particles show liquid vorticity effects which in our opinion represents the major cleaning mechanism.

Impact of cross-sectional root canal shape on filled canal volume and remaining root filling material after retreatment.

PubMed

Rechenberg, D K; Paqué, F

2013-06-01

To assess the impact of cross-sectional root canal shape (CSRCS) on the canal volume that can be filled and the root filling material that remains following a subsequent retreatment procedure. A total of 15 extracted two-rooted human maxillary premolars and 15 mandibular first molars were used. Both root canals in the premolars (N = 30) and the distal root canal in the molars (N = 15) were prepared using ProFile instruments and filled by lateral compaction using gutta-percha and AH Plus sealer. Canals were later retreated using the last ProFile used for instrumentation followed by two ProFiles of increasing size. Teeth were viewed in a μCT scanner before and after each treatment step. Defined and validated threshold levels were used to differentiate empty root canal volumes, root dentine and root filling materials from each other. CSRCS was defined as the averaged ratio between bucco-lingual and mesio-distal canal diameter (round ≤ 1, oval 1-2, long oval 2-4 and flattened ≥ 4), determined for each 1 mm over the total root length. Data were averaged between the two canals in premolars, only the distal canals were assessed in molars. Parametric and non-parametric tests were used to statistically compare the data, alpha = 0.01. Canals in premolars had a round CSRCS after preparation (1.0 ± 0.0), whereas distal counterparts in molars were oval (1.6 ± 0.5). Significantly (P < 0.01) more canal volume could be filled, and significantly less filling material remained after retreatment in premolars compared with mandibular molar distal canals. There was a high correlation between CSRCS, filled canal volume and remaining filling material. The endodontic procedures under investigation were significantly influenced by the cross-sectional root canal shape. © 2012 International Endodontic Journal. Published by Blackwell Publishing Ltd.

[Development of a system for ultrasonic three-dimensional reconstruction of fetus].

PubMed

Baba, K

1989-04-01

We have developed a system for ultrasonic three-dimensional (3-D) fetus reconstruction using computers. Either a real-time linear array probe or a convex array probe of an ultrasonic scanner was mounted on a position sensor arm of a manual compound scanner in order to detect the position of the probe. A microcomputer was used to convert the position information to what could be recorded on a video tape as an image. This image was superimposed on the ultrasonic tomographic image simultaneously with a superimposer and recorded on a video tape. Fetuses in utero were scanned in seven cases. More than forty ultrasonic section image on the video tape were fed into a minicomputer. The shape of the fetus was displayed three-dimensionally by means of computer graphics. The computer-generated display produced a 3-D image of the fetus and showed the usefulness and accuracy of this system. Since it took only a few seconds for data collection by ultrasonic inspection, fetal movement did not adversely affect the results. Data input took about ten minutes for 40 slices, and 3-D reconstruction and display took about two minutes. The system made it possible to observe and record the 3-D image of the fetus in utero non-invasively and therefore is expected to make it much easier to obtain a 3-D picture of the fetus in utero.

A 3D ultrasound scanner: real time filtering and rendering algorithms.

PubMed

Cifarelli, D; Ruggiero, C; Brusacà, M; Mazzarella, M

1997-01-01

The work described here has been carried out within a collaborative project between DIST and ESAOTE BIOMEDICA aiming to set up a new ultrasonic scanner performing 3D reconstruction. A system is being set up to process and display 3D ultrasonic data in a fast, economical and user friendly way to help the physician during diagnosis. A comparison is presented among several algorithms for digital filtering, data segmentation and rendering for real time, PC based, three-dimensional reconstruction from B-mode ultrasonic biomedical images. Several algorithms for digital filtering have been compared as relates to processing time and to final image quality. Three-dimensional data segmentation techniques and rendering has been carried out with special reference to user friendly features for foreseeable applications and reconstruction speed.

Implementation of efficient trajectories for an ultrasonic scanner using chaotic maps

NASA Astrophysics Data System (ADS)

Almeda, A.; Baltazar, A.; Treesatayapun, C.; Mijarez, R.

2012-05-01

Typical ultrasonic methodology for nondestructive scanning evaluation uses systematic scanning paths. In many cases, this approach is time inefficient and also energy and computational power consuming. Here, a methodology for the scanning of defects using an ultrasonic echo-pulse scanning technique combined with chaotic trajectory generation is proposed. This is implemented in a Cartesian coordinate robotic system developed in our lab. To cover the entire search area, a chaotic function and a proposed mirror mapping were incorporated. To improve detection probability, our proposed scanning methodology is complemented with a probabilistic approach of discontinuity detection. The developed methodology was found to be more efficient than traditional ones used to localize and characterize hidden flaws.

Integration of terrestrial laser scanner, ultrasonic and petrographical data in the diagnostic process on stone building materials

NASA Astrophysics Data System (ADS)

Casula, Giuseppe; Fais, Silvana; Giovanna Bianchi, Maria; Cuccuru, Francesco; Ligas, Paola

2015-04-01

The Terrestrial Laser Scanner (TLS) is a modern contactless non-destructive technique (NDT) useful to 3D-model complex-shaped objects with a few hours' field survey. A TLS survey produces very dense point clouds made up of coordinates of point and radiometric information given by the reflectivity parameter i.e. the ratio between the amount of energy emitted by the sensor and the energy reflected by the target object. Modern TLSs used in architecture are phase instruments where the phase difference obtained by comparing the emitted laser pulse with the reflected one is proportional to the sensor-target distance expressed as an integer multiple of the half laser wavelength. TLS data are processed by registering point clouds i.e. by referring them to the same reference frame and by aggregation after a fine registration procedure. The resulting aggregate point cloud can be compared with graphic primitives as single or multiple planes, cylinders or spheres, and the resulting residuals give a morphological map that affords information about the state of conservation of the building materials used in historical or modern buildings, in particular when compared with other NDT techniques. In spite of its great productivity, the TLS technique is limited in that it is unable to penetrate the investigated materials. For this reason both the 3D residuals map and the reflectivity map need to be correlated with the results of other NDT techniques such as the ultrasonic method, and a complex study of the composition of building materials is also necessary. The application of a methodology useful to evaluate the quality of stone building materials and locate altered or damaged zones is presented in this study based on the integrated application of three independent techniques, two non destructive such as the TLS and the ultrasonic techniques in the 24-54 kHz range, and a third to analyze the petrographical characteristics of the stone materials, mainly the texture, with optical and

Self-demodulation of amplitude-modulated signal components in amplitude-modulated bone-conducted ultrasonic hearing

NASA Astrophysics Data System (ADS)

Ito, Kazuhito; Nakagawa, Seiji

2015-07-01

A novel hearing aid system utilizing amplitude-modulated bone-conducted ultrasound (AM-BCU) is being developed for use by profoundly deaf people. However, there is a lack of research on the acoustic aspects of AM-BCU hearing. In this study, acoustic fields in the ear canal under AM-BCU stimulation were examined with respect to the self-demodulation effect of amplitude-modulated signal components generated in the ear canal. We found self-demodulated signals with an audible sound pressure level related to the amplitude-modulated signal components of bone-conducted ultrasonic stimulation. In addition, the increases in the self-demodulated signal levels at low frequencies in the ear canal after occluding the ear canal opening, i.e., the positive occlusion effect, indicate the existence of a pathway by which the self-demodulated signals pass through the aural cartilage and soft tissue, and radiate into the ear canal.

Efficacy of clinical and radiological methods to identify second mesiobuccal canals in maxillary first molars.

PubMed

Abuabara, Allan; Baratto-Filho, Flares; Aguiar Anele, Juliana; Leonardi, Denise Piotto; Sousa-Neto, Manoel Damião

2013-01-01

The success of endodontic treatment depends on the identification of all root canals. Technological advances have facilitated this process as well as the assessment of internal anatomical variations. The aim of this study was to compare the efficacy of clinical and radiological methods in locating second mesiobuccal canals (MB2) in maxillary first molars. Fifty patients referred for analysis; access and clinical analysis; cone-beam endodontic treatment of their maxillary first molars were submitted to the following assessments: analysis; access and clinical analysis; cone-beam computed tomography (CBCT); post-CBCT clinical analysis; clinical analysis using an operating microscope; and clinical analysis after Start X ultrasonic inserts in teeth with negative results in all previous analyses. Periapical radiographic analysis revealed the presence of MB2 in four (8%) teeth, clinical analysis in 25 (50%), CBCT analysis in 27 (54%) and clinical analysis following CBCT and using an operating microscope in 27 (54%) and 29 (58%) teeth, respectively. The use of Start X ultrasonic inserts allowed one to detect two additional teeth with MB2 (62%). According to Vertucci's classification 48% of the mesiobuccal canals found were type I, 28% type II, 18% type IV and 6% type V. Statistical analysis showed no significant differences (p > 0.5) in the ability of CBCT to detect MB2 canals when compared with clinical assessment with or without an operating microscope. A significant difference (p < 0.001)was found only between periapical radiography and clinical/CBCT evaluations. Combined use of different methods increased the detection ofthe second canal in MB roots, but without statistical difference among CBCT, operating microscope, Start X and clinical analysis.

Efficacy of Different Methods for Removing Root Canal Filling Material in Retreatment - An In-vitro Study.

PubMed

Kasam, Swetha; Mariswamy, Annapoorna Ballagere

2016-06-01

Although success of endodontic therapy has significantly improved in the last few decades due to the introduction of novel materials and techniques, failures of endodontic therapy requiring re-treatment still comprise a significant percentage of patients requiring root canal treatment. To evaluate and compare the effective removal of gutta percha and sealer, amount of apical debris extrusion and time required for gutta percha removal using various endodontic files. Total 48 extracted mandibular premolars were mounted on acrylic blocks and endodontic procedure was carried out using size 40 K file and obturated using guttapercha and zinc oxide eugenol sealer. After one month storage, samples were decoronated, mounted on screw capped vials and subjected to removal of obturated material by four instruments: H files, safe sided H files, protaper universal retreatment rotary system and ultrasonic retreatment tip, grouped as 1, 2, 3, and 4 respectively. Only 2mm of obturated material from the coronal part was removed using no. 3 Gates Glidden drill, guttapercha was softened with a drop of xylene for 2 mins for each canal and retreatment was performed. The retreatment procedure was said to be complete when no visible debris were observed on the instrument flutes. The samples split into two halves and examined under stereomicroscope, photographed, assessed using AUTOCAD software and percentage of remaining filling material in coronal, middle, apical thirds of the canal was calculated in mm(2). Retreatment time was recorded in seconds and apically extruded debris was assessed by microbalance in grams for each tooth. The data was analyzed by using descriptive statistics, ANOVA and Scheffe's post hoc test through SPSS for windows (v 16.0). The ultrasonic retreatment tip had less percentage of residual guttapercha/sealer, shorter mean operating time and little apical extrusion with a significant difference (p<0.05) between the other groups. All techniques retained guttapercha

Efficacy of Different Methods for Removing Root Canal Filling Material in Retreatment - An In-vitro Study

PubMed Central

Mariswamy, Annapoorna Ballagere

2016-01-01

Introduction Although success of endodontic therapy has significantly improved in the last few decades due to the introduction of novel materials and techniques, failures of endodontic therapy requiring re-treatment still comprise a significant percentage of patients requiring root canal treatment. Aim To evaluate and compare the effective removal of gutta percha and sealer, amount of apical debris extrusion and time required for gutta percha removal using various endodontic files. Materials and Methods Total 48 extracted mandibular premolars were mounted on acrylic blocks and endodontic procedure was carried out using size 40 K file and obturated using guttapercha and zinc oxide eugenol sealer. After one month storage, samples were decoronated, mounted on screw capped vials and subjected to removal of obturated material by four instruments: H files, safe sided H files, protaper universal retreatment rotary system and ultrasonic retreatment tip, grouped as 1, 2, 3, and 4 respectively. Only 2mm of obturated material from the coronal part was removed using no. 3 Gates Glidden drill, guttapercha was softened with a drop of xylene for 2 mins for each canal and retreatment was performed. The retreatment procedure was said to be complete when no visible debris were observed on the instrument flutes. The samples split into two halves and examined under stereomicroscope, photographed, assessed using AUTOCAD software and percentage of remaining filling material in coronal, middle, apical thirds of the canal was calculated in mm2. Retreatment time was recorded in seconds and apically extruded debris was assessed by microbalance in grams for each tooth. The data was analyzed by using descriptive statistics, ANOVA and Scheffe’s post hoc test through SPSS for windows (v 16.0). Results The ultrasonic retreatment tip had less percentage of residual guttapercha/sealer, shorter mean operating time and little apical extrusion with a significant difference (p<0.05) between the

Irrigation dynamics associated with positive pressure, apical negative pressure and passive ultrasonic irrigations: a computational fluid dynamics analysis.

PubMed

Chen, José Enrique; Nurbakhsh, Babak; Layton, Gillian; Bussmann, Markus; Kishen, Anil

2014-08-01

Complexities in root canal anatomy and surface adherent biofilm structures remain as challenges in endodontic disinfection. The ability of an irrigant to penetrate into the apical region of a canal, along with its interaction with the root canal walls, will aid in endodontic disinfection. The aim of this study was to qualitatively examine the irrigation dynamics of syringe irrigation with different needle tip designs (open-ended and closed-ended), apical negative pressure irrigation with the EndoVac® system, and passive ultrasonic-assisted irrigation, using a computational fluid dynamics model. Syringe-based irrigation with a side-vented needle showed a higher wall shear stress than the open-ended but was localised to a small region of the canal wall. The apical negative pressure mode of irrigation generated the lowest wall shear stress, while the passive-ultrasonic irrigation group showed the highest wall shear stress along with the greatest magnitude of velocity. © 2013 The Authors. Australian Endodontic Journal © 2013 Australian Society of Endodontology.

A simplified technique of orthograde MTA obturation on the elected canals of posterior teeth: Two case reports.

PubMed

Wahengbam, Brucelee; Wahengbam, Pragya; Tikku, Aseem Prakash

2014-01-01

This article suggests a simplified technique of orthograde MTA obturation in less accessible canal(s) of posteriors teeth without using costly ultrasonics or specialised carrier. Essentially few finger pluggers, absorbent points and a simple canal projection method were used. The orifice(s) of the elected canal(s) to be obturated with MTA were projected onto the external occlusal surface for easy delivery and predictive instrumentation. The idea was based on 'easy access', 'working one canal with one mix at one time', 'thorough condensation' and 'removal of excess moisture'. In case I, palatal canal of tooth no. 2 with gross apical perforation and suspected VRF was obturated with MTA. And in Case II, tooth no. 19 presented with incomplete furcal fracture extending into the canal was obturated with MTA in all 3 canals unitarily. Dense homogenous MTA obturation was achieved and both cases healed uneventfully.

Photoactivation of curcumin and sodium hypochlorite to enhance antibiofilm efficacy in root canal dentin.

PubMed

Neelakantan, Prasanna; Cheng, Cheng Qing; Ravichandran, Vinoddhine; Mao, Teresa; Sriraman, Priyanka; Sridharan, Swetha; Subbarao, Chandana; Sharma, Subash; Kishen, Anil

2015-03-01

To test the effect of ultrasonic or light activated curcumin and sodium hypochlorite against Enterococcus faecalis biofilms in vitro. E. faecalis biofilms were grown within root canals (n=175) and divided into 7 groups (n=25). Group 1, sterile saline; group 2, 3% sodium hypochlorite; group 3, 3% sodium hypochlorite activated with ultrasonic files (30s cycles for 4min); group 4, 3% sodium hypochlorite irradiated with blue light (1200mw/cm(2) for 4min); group 5, curcumin (2.5mg/mL); group 6, curcumin (2.5mg/mL) activated with ultrasonic files (30s cycles for 4min); group 7, curcumin (2.5mg/mL) irradiated with blue light. The biofilms' ultrastructure was examined using scanning electron microscopy. Bacterial viability was assessed by confocal microscopy. Data were analyzed by one-way ANOVA and Student-Newman-Keuls test (P=0.05). The quantitative analysis of the colony-forming units was carried out from dentinal shaving and analyzed by One-way ANOVA and Tukey multiple comparison test (P=0.05). All treatment groups showed a significantly higher percentage of dead bacteria than the saline control (P<0.05). The percentage of dead bacteria was significantly higher when light activated curcumin was used (P<0.05). At both depths (200 and 400 microns), light activated curcumin showed no growth of bacteria. Light activation produced significantly higher antibacterial efficacy than ultrasonic agitation, with light activated curcumin producing the maximum elimination of biofilm bacteria within the root canal lumen and dentinal tubules. Copyright © 2014 Elsevier B.V. All rights reserved.

Interpretation of multispectral and infrared thermal surveys of the Suez Canal Zone, Egypt

NASA Technical Reports Server (NTRS)

Elshazly, E. M.; Hady, M. A. A. H.; Hafez, M. A. A.; Salman, A. B.; Morsy, M. A.; Elrakaiby, M. M.; Alaassy, I. E. E.; Kamel, A. F.

1977-01-01

Remote sensing airborne surveys were conducted, as part of the plan of rehabilitation, of the Suez Canal Zone using I2S multispectral camera and Bendix LN-3 infrared passive scanner. The multispectral camera gives four separate photographs for the same scene in the blue, green, red, and near infrared bands. The scanner was operated in the microwave bands of 8 to 14 microns and the thermal surveying was carried out both at night and in the day time. The surveys, coupled with intensive ground investigations, were utilized in the construction of new geological, structural lineation and drainage maps for the Suez Canal Zone on a scale of approximately 1:20,000, which are superior to the maps made by normal aerial photography. A considerable number of anomalies belonging to various types were revealed through the interpretation of the executed multispectral and infrared thermal surveys.

The fluid mechanics of root canal irrigation.

PubMed

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

Evaluation of bond strength of various epoxy resin based sealers in oval shaped root canals.

PubMed

Cakici, Fatih; Cakici, Elif Bahar; Ceyhanli, Kadir Tolga; Celik, Ersan; Kucukekenci, Funda Fundaoglu; Gunseren, Arif Onur

2016-09-30

The aim of this study was to evaluate the bond strength of AH plus, Acroseal, and Adseal to the root canal dentin. A total of 36 single-rooted, mandibular premolar teeth were used. Root canal shaping procedures were performed with ProTaper rotary instruments (Dentsply Maillefer) up to size F4. The prepared samples were then randomly assembled into 3 groups (n = 12). For each group, an ultrasonic tip (size 15, 0.02 taper) which was also coated with an epoxy resin based sealer and placed 2 mm shorter than the working length. The sealer was then activated for 10 s. A push-out test was used to measure the bond strength between the root canal dentine and the sealer. Kruskal-Wallis test to evaluate the push-out bond strength of epoxy based sealer (P = 0.05). The failure mode data were statistically analyzed using Pearson's chi square test (P = 0.05). Kruskal-Wallis test indicated that there were no statistically significant difference among the push out bond strength values of 3 mm (p = 0.123) and 6 mm (P = 0.057) for groups, there was statistically significant difference push out bond strength value of 9 mm (P = 0.032). Pearson's chi square test showed statistically significant differences for the failure types among the groups. Various epoxy resin based sealers activated ultrasonically showed similar bond strength in oval shaped root canals. Apical sections for all groups have higher push out bond strength values than middle and coronal sections.

Effect of ultrasonic tip designs on intraradicular post removal.

PubMed

Aguiar, Anny Carine Barros; de Meireles, Daniely Amorim; Marques, André Augusto Franco; Sponchiado Júnior, Emílio Carlos; Garrido, Angela Delfina Bitencourt; Garcia, Lucas da Fonseca Roberti

2014-11-01

To evaluate the effect of different ultrasonic tip designs on intraradicular post removal. The crowns of forty human canine teeth were removed, and after biomechanical preparation and filling, the roots were embedded in acrylic resin blocks. The post spaces were made, and root canal molding was performed with self-cured acrylic resin. After casting (Cu-Al), the posts were cemented with zinc phosphate cement. The specimens were randomly separated into 4 groups (n = 10), as follows: G1 - no ultrasonic vibration (control); G2 - ultrasonic vibration using an elongated cylindrical-shaped and active rounded tip; G3 - ultrasonic vibration with a flattened convex and linear active tip; G4 - ultrasonic vibration with active semicircular tapered tip. Ultrasonic vibration was applied for 15 seconds on each post surface and tensile test was performed in a Universal Testing Machine (Instron 4444 - 1 mm/min). G4 presented the highest mean values, however, with no statistically significant difference in comparison to G3 (P > 0.05). G2 presented the lowest mean values with statistically significant difference to G3 and G4 (P < 0.05). Ultrasonic vibration with elongated cylindrical-shaped and active rounded tip was most effective in reducing force required for intraradicular post removal.

Pulse-Echo Phased Array Ultrasonic Inspection of Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS)

NASA Technical Reports Server (NTRS)

Johnston, Pat H.

2010-01-01

A PRSEUS test article was subjected to controlled impact on the skin face followed by static and cyclic axial compressions. Phased array ultrasonic inspection was conducted before impact, and after each of the test conditions. A linear phased array probe with a manual X-Y scanner was used for interrogation. Ultrasound showed a delamination between the skin and stringer flange adjacent to the impact. As designed, the stitching in the flange arrested the lateral flaw formation. Subsequent ultrasonic data showed no delamination growth due to continued loading. Keywords: Phased Array, Ultrasonics, Composites, Out-of-Autoclave

Efficacy of ultrasonic activation of NaOCl and orange oil in removing filling material from mesial canals of mandibular molars with and without isthmus

PubMed Central

Barreto, Mirela Sangoi; da Rosa, Ricardo Abreu; Santini, Manuela Favarin; Cavenago, Bruno Cavalini; Duarte, Marco Antônio Húngaro; Bier, Carlos Alexandre Souza; Só, Marcos Vinícius Reis

2016-01-01

ABSTRACT Objectives The aim of this study was to evaluate the volume of remaining filling material after passive ultrasonic irrigation (PUI) of sodium hypochlorite (NaOCl) and orange oil in mesial canals of mandibular molars, with and without isthmus. Material and Methods Thirty mesial roots of mandibular molars were divided according to the presence or absence of isthmus. Canals were prepared and filled (Micro-CT #1). Filling was removed using rotary instruments, and specimens were sub-divided into three groups according to the irrigation procedures: Conventional – conventional irrigation with NaOCl, PUI/NaOCl – PUI of NaOCl (three activations, 20 seconds each), and PUI/orange oil – PUI of orange oil (Micro-CT#2). Specimens were enlarged using the X2 and X3 ProTaper Next instruments and submitted to the same irrigation protocols (Micro-CT #3). Results No differences were found between the experimental groups in each stage of assessment (P>0.05). The volume of residual filling material was similar to those in Micro-CT #2 and Micro-CT #3, but lower than those observed in Micro-CT #1 (P<0.05). When groups were pooled according to the presence or absence of an isthmus, volume of residual filling material was higher in specimens presenting isthmus (P<0.05). Conclusions PUI of NaOCl or orange oil did not improve filling removal. Isthmus consists in an anatomical obstacle that impairs the removal of filling material. PMID:26200525

Ultrasonic characterization of damage in a simulated CF-18 composite structure

NASA Astrophysics Data System (ADS)

McRae, K. I.; Finlayson, R. D.; Sturrock, W. R.; Liesch, D. S.

1993-02-01

A simulated CF-18 aircraft door component was constructed and subjected to treatment during manufacturing with the object of inducing damage in the composite material in a known and well-defined manner. The simulated component was then sent to participants in a nondestructive evaluation study. Results are reported for tests conducted with a scanning apparatus and data acquisition system which consisted of three components: ultrasonic transducer and scanner comprising a two-axis scanning frame to which a modified commercial transducer was attached; an acquisition system for ultrasonic data known as Signal Processing Ultrasonic Device (SPUD); and a data analysis and display system (DETECT/NDE) specifically designed to manipulate large three dimensional ultrasonic data sets. A series of five large-area scans was performed, each scan about 52 cm square. A total of eight regions of interest were identified for a more detailed analysis of the delamination damage, seven detailed scans covering a 13-cm square and one covering a 20.8-cm square. It was often possible to identify the probable source of the damage as that resulting from impact or caused by overloading of fasteners. Flaws of all significant dimensions were located and fully characterized using the ultrasonic procedure.

Effect of sonic and ultrasonic activation on organic tissue dissolution from simulated grooves in root canals using sodium hypochlorite and EDTA.

PubMed

Conde, A J; Estevez, R; Loroño, G; Valencia de Pablo, Ó; Rossi-Fedele, G; Cisneros, R

2017-10-01

To compare soft-tissue dissolution by sodium hypochlorite, with an EDTA intermediate rinse, with or without activation with passive ultrasonic activation (PUI) or sonic activation using the Endoactivator (EA) or Eddy tips (ED). The root canals of eighty-three human maxillary central incisors were chemo-mechanically prepared and the teeth split. A standardized longitudinal intracanal groove was created in one of the root halves. Eighty-three porcine palatal mucosa samples were collected, adapted to fit into the grooves and weighed. The re-assembled specimens were randomly divided into four experimental groups (n = 20), based on the final rinse: no activation; EA; PUI; ED, using 2.5% sodium hypochlorite, with an EDTA intermediate rinse. A control group (n = 3) was irrigated with distilled water without activation. The solutions were delivered using a syringe and needle 2 mm from working length. Total irrigation time was 150 s, including 60 s of activation in the specific groups. The study was carried out at 36 ± 2 °C. The porcine palatal mucosa samples were weighed after completion of the assays. Student paired t-test and anova were used to assess the intra- and intergroup weight changes. The multiple comparisons were evaluated using Bonferroni correction (α = 0.05). Weight loss occurred in all experimental groups. Irrigant activation resulted in greater weight loss when compared to the nonactivated group [vs. EA (P = 0.001); vs. PUI (P < 0.001); vs. ED (P < 0.001)]. No significant differences were found amongst the different activation systems. Activation increased the tissue-dissolving activity of irrigants from artificial grooves in root canals of maxillary central incisors. © 2016 International Endodontic Journal. Published by John Wiley & Sons Ltd.

A new ultrasonic real-time scanner featuring a servo-controlled transducer displaying a sector image.

PubMed

Skolnick, M L; Matzuk, T

1978-08-01

This paper describes a new real-time servo-controlled sector scanner that produces high-resolution images similar to phased-array systems, but possesses the simplicity of design and low cost best achievable in a mechanical sector scanner. Its unique feature is the transducer head which contains a single moving part--the transducer. Frame rates vary from 0 to 30 degrees and the sector angle from 0 to 60 degrees. Abdominal applications include: differentiation of vascular structures, detection of small masses, imaging of diagonally oriented organs. Survey scanning, and demonstration of regions difficult to image with contact scanners. Cardiac uses are also described.

[Effects of different techniques on removal of vapor lock in the apical region of curved canals: a cone-beam computed tomography study].

PubMed

Su, Z; Bai, Y H; Hou, X M

2017-02-18

To compare the effect of four different techniques on removal of vapor lock in the apical region of curved root canals. Forty simulated resin root canals with 45° curvature were prepared using WaveOne Primary, then the apical foramen were sealed with soft wax. The teeth were divided randomly into 4 groups thereafter (n=10). Contract solution was injected into the canals using a 30 G side-vented needle and scanned with cone-beam CT (CBCT) to identify the volume of the vapor lock. Four different techniques including photon-induced photoacoustic streaming (PIPS) laser-activated irrigation, gutta-percha cone technique, ultrasonic irrigation, and sonic irrigation were used to remove the vapor locks in the root canals. The residual volume of the vapor lock was identified again using CBCT scanning data. Accordingly, the reduction rates of the vapor lock were calculated. Furthermore, the initial and residual vapor lock length was calculated. The data were analyzed by using the One-way ANOVA analysis and Kruskal-Wallis H test at a significance level of P<0.05. There was no significant difference in the initial vapor lock volume (P>0.05). Residual volume of the vapor lock for PIPS laser-activated irrigation was 0 mm(3), and that for gutta-percha cone technique was (0.02±0.07) mm3, significantly lower than those of ultrasonic and sonic irrigation, the values being (0.20±0.09) mm(3) and (0.23±0.06) mm(3) (P<0.001), respectively. The reduction rates of the vapor lock of PIPS laser-activated irrigation and gutta-percha cone technique were 100.00% (100.00%, 100.00%) and 100.00% (77.66%, 100.00%), respectively, significantly higher than those of ultrasonic irrigation [70.37% (56.41%, 91.43%)] and sonic irrigation [63.54% (51.47%, 74.00%), P<0.001]. The length of the residual vapor lock for PIPS laser-activated irrigation was 0 mm, and that for gutta-percha cone technique was (0.15±0.47) mm, significantly lower than those of ultrasonic and sonic irrigation, values being (2.21�

Confocal laser scanning, scanning electron, and transmission electron microscopy investigation of Enterococcus faecalis biofilm degradation using passive and active sodium hypochlorite irrigation within a simulated root canal model.

PubMed

Mohmmed, Saifalarab A; Vianna, Morgana E; Penny, Matthew R; Hilton, Stephen T; Mordan, Nicola; Knowles, Jonathan C

2017-08-01

Root canal irrigation is an important adjunct to control microbial infection. The aim of this study was to investigate the effect of 2.5% (wt/vol) sodium hypochlorite (NaOCl) agitation on the removal, killing, and degradation of Enterococcus faecalis biofilm. A total of 45 root canal models were manufactured using 3D printing with each model comprising an 18 mm length simulated root canal of apical size 30 and taper 0.06. E. faecalis biofilms were grown on the apical 3 mm of the models for 10 days. A total of 60 s of 9 ml of 2.5% NaOCl irrigation using syringe and needle was performed, the irrigant was either left stagnant in the canal or agitated using manual (Gutta-percha), sonic, and ultrasonic methods for 30 s. Following irrigation, the residual biofilms were observed using confocal laser scanning, scanning electron, and transmission electron microscopy. The data were analyzed using one-way ANOVA with Dunnett post hoc tests at a level of significance p ≤ .05. Consequence of root canal irrigation indicate that the reduction in the amount of biofilm achieved with the active irrigation groups (manual, sonic, and ultrasonic) was significantly greater when compared with the passive and untreated groups (p < .05). Collectively, finding indicate that passive irrigation exhibited more residual biofilm on the model surface than irrigant agitated by manual or automated (sonic, ultrasonic) methods. Total biofilm degradation and nonviable cells were associated with the ultrasonic group. © 2017 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

In vitro study of calcium hydroxide removal from mandibular molar root canals.

PubMed

Ma, Jingzhi; Shen, Ya; Yang, Yan; Gao, Yuan; Wan, Pan; Gan, Yan; Patel, Payal; Curtis, Allison; Khakpour, Mehrzad; Haapasalo, Markus

2015-04-01

Previous studies have shown the difficulty in removing calcium hydroxide (Ca[OH]2) paste from the root canals before root filling. Mesial and distal canals of 30 mandibular molars were prepared with the WaveOne Primary (25/.08) and Large file (40/.08) (Dentsply Tulsa Dental Specialties, Tulsa, OK), respectively. All canals were then filled with Ca(OH)2. The teeth were divided into the following 3 treatment groups (each with n = 10): (1) instrumentation with needle irrigation, (2) instrumentation with irrigation and passive ultrasonic activation (PUI), and (3) the GentleWave system (Sonendo, Inc, Laguna Hills, CA) without instrumentation. The irrigation time in each group was 7.5 minutes. To further test the efficiency of the GentleWave system, shorter times of 90 seconds were tested using water alone. Reconstructed micro-computed tomographic scans were used to measure the volume of the canals and Ca(OH)2 after instrumentation, initial filling of Ca(OH)2, and after its removal. The percentage of Ca(OH)2 remaining in the canals was calculated. None of the 10 teeth (30 canals) in the conventional irrigation and PUI groups were completely cleaned of Ca(OH)2 in 7.5 minutes. In the apical third of mesial and distal canals, respectively, conventional irrigation removed 47.82% ± 16.36% and 77.68% ± 12.82%, PUI removed 61.66% ± 25.54% and 88.85 ± 12.06%, and the GentleWave system removed significantly more Ca(OH)2 (P < .05) with 100% and 98.78% ± 3.84%. Additional experiments in 10 teeth, using only water as the irrigant, revealed that the GentleWave system removed 99.85% and 99.97% of Ca(OH)2 within 90 seconds without the use of any instruments in the mesial and distal canals, respectively. The study confirms the difficulty to remove Ca(OH)2 from root canals using conventional methods. The GentleWave system removed the paste within 90 seconds using water irrigation alone. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights

In vitro comparative study of manual and mechanical rotary instrumentation of root canals using computed tomography.

PubMed

Limongi, Orlando; de Albuquerque, Diana Santana; Baratto Filho, Flares; Vanni, José Roberto; de Oliveira, Elias P Motcy; Barletta, Fernando Branco

2007-01-01

This in vitro study compared, using computed tomography (CT), the amount of dentin removed from root canal walls by manual and mechanical rotary instrumentation techniques. Forty mandibular incisors with dental crown and a single canal were selected. The teeth were randomly assigned to two groups, according to the technique used for root canal preparation: Group I - manual instrumentation with stainless steel files; Group II - mechanical instrumentation with RaCe rotary nickel-titanium instruments. In each tooth, root dentin thickness of the buccal, lingual, mesial and distal surfaces in the apical, middle and cervical thirds of the canal was measured (in mm) using a multislice CT scanner (Siemens Emotion, Duo). Data were stored in the SPSS v. 11.5 and SigmaPlot 2001 v. 7.101 softwares. After crown opening, working length was determined, root canals were instrumented and new CT scans were taken for assessment of root dentin thickness. Pre- and post-instrumentation data were compared and analyzed statistically by ANOVA and Tukey's post-hoc test for significant differences (p=0.05). Based on the findings of this study, it may be concluded that regarding dentin removal from root canal walls during instrumentation, neither of the techniques can be considered more effective than the other.

Cleaning of Root Canal System by Different Irrigation Methods.

PubMed

Tanomaru-Filho, Mário; Miano, Lucas Martinati; Chávez-Andrade, Gisselle Moraima; Torres, Fernanda Ferrari Esteves; Leonardo, Renato de Toledo; Guerreiro-Tanomaru, Juliane Maria

2015-11-01

The aim of this study was to compare the cleaning of main and lateral canals using the irrigation methods: negative pressure irrigation (EndoVac system), passive ultrasonic irrigation (PUI) and manual irrigation (MI). Resin teeth were used. After root canal preparation, four lateral canals were made at 2 and 7 mm from the apex. Root canals were filled with contrast solution and radiographed pre- and post-irrigation using digital radiographic system [radiovisiography (RVG)]. The irrigation protocols were: MI1-manual irrigation [22 G needle at 5 mm short of working length-WL]; MI2-manual irrigation (30G needle at 2 mm short of WL); PUI; EV1-EndoVac (microcannula at 1 mm short of WL); EV2-Endovac (microcannula at 3 mm short of WL). The obtained images, initial (filled with contrast solution) and final (after irrigation) were analyzed by using image tool 3.0 software. Statistical analysis was performed by analysis of variance (ANOVA) and Tukey tests (5% significance level). EV1 and EV2, followed by PUI showed better cleaning capacity than manual irrigation (MI1 and MI2) (p < 0.05). Negative pressure irrigation and PUI promoted better cleaning of main and simulated lateral canals. Conventional manual irrigation technique may promote less root canal cleaning in the apical third. For this reason, the search for other irrigation protocols is important, and EndoVac and PUI are alternatives to contribute to irrigation effectiveness.

Evaluation of Root Canal Configuration of Mandibular First Molars in a Palestinian Population by Using Cone-Beam Computed Tomography: An Ex Vivo Study

PubMed Central

Mukhaimer, Raed Hakam

2014-01-01

Aim. The purpose of this study was to investigate the number of canals and variations in root canal configuration in the mandibular permanent first molar teeth of a Palestinian population using cone-beam computed tomography (CBCT). Methods. A sample of 320 extracted double-rooted mandibular permanent first molars from Palestinian population was collected for this study and scanned with CBCT scanner. The following observations were made: number of root canals per root and canal configuration in each root based on Vertucci's classification. Results. Of the 320 mandibular first molars analyzed, 174 (54.4%) had three canals, 132 teeth (41.3%) had four canals, and only four teeth had two canals. The most common canal configuration in the mesial roots was Vertucci type IV (53.8%) followed by type II (38.8%). In the distal roots, the most prevalent canal configuration was Vertucci type I (57.5%) followed by type II ( 22.5%) and type III (10.6%). Conclusion. Our results showed that the number of canals and canal configuration in Palestinian population were consistent with previously reported data. The present study also indicates that CBCT is helpful as a diagnostic tool for the investigation of root canal morphology. PMID:27379321

[Evaluation of the cavity cleaning of ultrasonic instruments and slow-speed handpiece in posterior teeth root-end preparation].

PubMed

Zhang, Ping-juan; Chen, Wen-xia; Zeng, Qi-xin; Xie, Fang-fang

2013-04-01

To compare the cleanliness of root end preparations by using ultrasonic instrumentation and slow-speed handpiece. Thirty-two mesial roots of the first mandibular molars with two canals and mature root apices were assigned randomly to 2 groups, each group had 16 teeth. The root-end preparations were made respectively using ultrasonic diamond tip Berutti and NiTi tip RE2 and slow-speed handpiece with No.2 round bur. Root end cavities were examined under scanning electron microscope for further evaluation of the superficial debris and smear layer of the root end preparations. SPSS 13.0 software package was used for Kruskal Wallis test. Ultrasonic preparation had significantly less superficial debris and smear layer than slow-speed handpiece preparation (P<0.05). Ultrasonic instrument creates cleaner surfaces for root end cavities than slow-speed handpiece preparation in posterior teeth root end preparation.

Ultrasonic scanning system for in-place inspection of brazed tube joints

NASA Technical Reports Server (NTRS)

Haynes, J. L.; Wages, C. G.; Haralson, H. S. (Inventor)

1973-01-01

A miniaturized ultrasonic scanning system for nondestructive in-place, non-immersion testing of brazed joints in stainless-steel tubing is described. The system is capable of scanning brazed tube joints, with limited clearance access, in 1/4 through 5/8 inch union, tee, elbow and cross configurations. The system has the capability to detect defective conditions now associated with material density changes in addition to those which are depended upon density variations. The system includes a miniaturized scanning head assembly that fits around a tube joint and rotates the transducer around and down the joint in a continuous spiral motion. The C-scan recorder is similar in principle to conventional models except that it was specially designed to track the continuous spiral scan of the tube joint. The scanner and recorder can be operated with most commercially available ultrasonic flaw detectors.

The effect of ultrasonic post instrumentation on root surface temperature.

PubMed

Huttula, Andrew S; Tordik, Patricia A; Imamura, Glen; Eichmiller, Frederick C; McClanahan, Scott B

2006-11-01

This study measured root surface temperature changes when ultrasonic vibration, with and without irrigation, was applied to cemented endodontic posts. Twenty-six, extracted, single-rooted premolars were randomly divided into two groups. Root lengths were standardized, canals instrumented, obturated, and posts cemented into prepared spaces. Thermocouples were positioned at two locations on the proximal root surfaces. Samples were embedded in plaster and brought to 37 degrees C in a water bath. Posts were ultrasonically vibrated for 4 minutes while continuously measuring temperature. Two-way ANOVA compared effects of water coolant and thermocouple location on temperature change. Root surface temperatures were significantly higher (p < 0.001) when posts were instrumented dry. A trend for higher temperatures was observed at coronal thermocouples of nonirrigated teeth and at apical thermocouples of irrigated teeth (p = 0.057). Irrigation during post removal with ultrasonics had a significant impact on the temperature measured at the external root surface.

Effect of Passive Ultrasonic Activation on Organic Tissue Dissolution from Simulated Grooves in Root Canals Using Sodium Hypochlorite with or without Surfactants and EDTA.

PubMed

Estevez, Roberto; Conde, Antonio J; Valencia de Pablo, Oliver; de la Torre, Francisco; Rossi-Fedele, Giampiero; Cisneros, Rafael

2017-07-01

The aim of this study was to evaluate the porcine palatal mucosa dissolution from artificial grooves using a final rinse with sodium hypochlorite (NaOCl) with or without a surfactant or ultrasonic activation (PUI). The root canals of 130 human maxillary central incisors were chemomechanically prepared and the teeth split. A standardized longitudinal intracanal groove was created in 1 of the root halves. One hundred thirty porcine palatal mucosa samples were collected, adapted in order to fit into the grooves, and weighed. The reassembled specimens were randomly divided in 3 experimental groups (n = 40) based on their irrigation protocol (ie, positive pressure [PP] and PUI during 15 [PUI-15] or 30 seconds [PUI-30]) and divided in subgroups according to the NaOCl preparation used: Vista 6% plain (Vista Dental Products, Racine, WI) or Chlor-XTRA (Vista Dental Products) (containing surfactant). An EDTA intermediate rinse was included. Palatal mucosa weights were measured after the assays. The intergroup weight changes were statistically analyzed. Complete dissolution did not occur in any sample. Chlor-XTRA subgroups were associated with increased weight reduction compared with Vista 6% plain subgroups; however, the differences were significant (P < .05) only for PP and PUI-15. PUI-30 increased weight reduction compared with PP for both hypochlorites and PUI-15 using Vista 6% plain (P < .05). PUI-30 with Vista 6% plain performed significantly better than PP with Chlor-XTRA (P < .05). The addition of a surfactant to NaOCl and/or PUI activation increased palatal mucosa dissolution within artificial grooves in the root canal of incisor teeth. PUI agitation was often able to compensate for the absence of surfactants. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Evaluation of Apical Vapor Lock Formation and comparative Evaluation of its Elimination using Three different Techniques: An in vitro Study.

PubMed

Agarwal, Anand; Deore, Rahul B; Rudagi, Kavitarani; Nanda, Zinnie; Baig, Mirza Osman; Fareez, Md Adil

2017-09-01

The aim of this study was (i) to evaluate the formation of air bubbles in the apical region of root canal (apical vapor lock) during syringe irrigation, using cone beam computed tomography (CBCT) and (ii) comparative evaluation of the elimination of an established vapor lock by EndoActivator, ultrasonics, and manual dynamic agitation (MDA), using CBCT. A total of 60 extracted human single-rooted teeth were equally divided into three groups of 20 teeth each. The samples were decoronated 17 mm from the apex, cleaned, and shaped to size F4 Protaper using 3% sodium hypochlorite. Samples were irrigated with 3% sodium hypochlorite + cesium chloride radiopaque dye, and preoperative CBCT images were obtained. After formation of apical vapor lock in the scanned teeth, EndoActivator (group I), passive ultrasonic irrigation (group II), and MDA with K-file (group III) were performed and the teeth were again placed in CBCT scanner and results analyzed using the chi-square test. The apical vapor lock was formed in all the samples. Out of the 20 teeth in each group, the apical vapor lock was eliminated in 18 samples of EndoActivator group (90%), 16 samples of ultrasonic group (80%), while it was eliminated in 10 samples by MDA (50%). It is concluded that (1) apical vapor lock is consistently formed during endodontic irrigation in closed canal systems and (2) sonic activation performs better than the ultrasonics and MDA in eliminating the apical vapor lock, with statistically significant difference between all the three groups (p < 0.05). The results suggest that the apical vapor lock (dead water zone) is consistently formed during routine endodontic irrigation which impedes irrigant penetration till the working length, thereby leading to inefficient debridement. Hence, to eliminate this vapor lock, techniques, such as sonics or ultrasonics should be used along with the irrigant after shaping and cleaning of the root canal.

Ultrasound backscatter tensor imaging (BTI): analysis of the spatial coherence of ultrasonic speckle in anisotropic soft tissues.

PubMed

Papadacci, Clement; Tanter, Mickael; Pernot, Mathieu; Fink, Mathias

2014-06-01

The assessment of fiber architecture is of major interest in the progression of myocardial disease. Recent techniques such as magnetic resonance diffusion tensor imaging (MR-DTI) or ultrasound elastic tensor imaging (ETI) can derive the fiber directions by measuring the anisotropy of water diffusion or tissue elasticity, but these techniques present severe limitations in a clinical setting. In this study, we propose a new technique, backscatter tensor imaging (BTI), which enables determination of the fiber directions in skeletal muscles and myocardial tissues, by measuring the spatial coherence of ultrasonic speckle. We compare the results to ultrasound ETI. Acquisitions were performed using a linear transducer array connected to an ultrasonic scanner mounted on a motorized rotation device with angles from 0° to 355° by 5° increments to image ex vivo bovine skeletal muscle and porcine left ventricular myocardial samples. At each angle, multiple plane waves were transmitted and the backscattered echoes recorded. The coherence factor was measured as the ratio of coherent intensity over incoherent intensity of backscattered echoes. In skeletal muscle, maximal/minimal coherence factor was found for the probe parallel/perpendicular to the fibers. In myocardium, the coherence was assessed across the entire myocardial thickness, and the position of maxima and minima varied transmurally because of the complex fibers distribution. In ETI, the shear wave speed variation with the probe angle was found to follow the coherence variation. Spatial coherence can thus reveal the anisotropy of the ultrasonic speckle in skeletal muscle and myocardium. BTI could be used on any type of ultrasonic scanner with rotating phased-array probes or 2-D matrix probes for noninvasive evaluation of myocardial fibers.

Ultrasound Backscatter Tensor Imaging (BTI): Analysis of the spatial coherence of ultrasonic speckle in anisotropic soft tissues

PubMed Central

Papadacci, Clement; Tanter, Mickael; Pernot, Mathieu; Fink, Mathias

2014-01-01

The assessment of fiber architecture is of major interest in the progression of myocardial disease. Recent techniques such as Magnetic Resonance (MR) Diffusion Tensor Imaging or Ultrasound Elastic Tensor Imaging (ETI) can derive the fiber directions by measuring the anisotropy of water diffusion or tissue elasticity, but these techniques present severe limitations in clinical setting. In this study, we propose a new technique, the Backscatter Tensor Imaging (BTI) which enables determining the fibers directions in skeletal muscles and myocardial tissues, by measuring the spatial coherence of ultrasonic speckle. We compare the results to ultrasound ETI. Acquisitions were performed using a linear transducer array connected to an ultrasonic scanner mounted on a motorized rotation device with angles from 0° to 355° by 5° increments to image ex vivo bovine skeletal muscle and porcine left ventricular myocardial samples. At each angle, multiple plane waves were transmitted and the backscattered echoes recorded. The coherence factor was measured as the ratio of coherent intensity over incoherent intensity of backscattered echoes. In skeletal muscle, maximal/minimal coherence factor was found for the probe parallel/perpendicular to the fibers. In myocardium, the coherence was assessed across the entire myocardial thickness, and the position of maxima and minima varied transmurally due to the complex fibers distribution. In ETI, the shear wave speed variation with the probe angle was found to follow the coherence variation. Spatial coherence can thus reveal the anisotropy of the ultrasonic speckle in skeletal muscle and myocardium. BTI could be used on any type of ultrasonic scanner with rotative phased-array probes or 2-D matrix probes for non-invasive evaluation of myocardial fibers. PMID:24859662

Endodontic treatment of a maxillary first molar with seven root canals confirmed with cone beam computer tomography - case report.

PubMed

Martins, Jorge N R

2014-06-01

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.

Interrelationships in the Variability of Root Canal Anatomy among the Permanent Teeth: A Full-Mouth Approach by Cone-Beam CT

PubMed Central

Peters, Ove A.; Maury, Elisabeth; Telmon, Norbert; Georgelin-Gurgel, Marie; Maret, Delphine

2016-01-01

Objectives In endodontic practice, clinicians should be aware of possible root canal anatomic variations. The aim of this study was to assess using CBCT acquisitions regarding whether one root canal anatomy of a tooth is associated with a specific anatomy of another tooth. Methods A total of 106 CBCT acquisitions were obtained using a CBCT scanner with 200μm voxel size. Numbers of roots and canals of the entire dentition were described. Bivariate analyses and logistic regressions were conducted to explore root canal anatomy on one tooth according to age, gender, jaw, side and the others teeth. Multiple correspondence analysis (MCA) was performed to correlate the different numbers of canals profiles. Results A total of 2424 teeth were analyzed. Independently from the other variables, the presence of an additional root canal on a mandibular incisor increases the risk of having an additional root canal on a mandibular premolar (OR [95%] 3.7 [1.0;13.2]). The mandibular molar variability increases in women compared to men (OR [95%] 0.4 [0.1; 0.9]). MCA showed correspondence between 2-canals maxillary incisor and canines and 5-canals maxillary molars, and some correlation between additional canal on maxillary and mandibular premolars. Conclusions Although CBCT examinations are conducted in the first intention of making a diagnosis or prognostic evaluation, medium FOV acquisitions could be used as an initial database thus furnishing preliminary evaluations and information. In endodontic practice, clinicians should be aware of possible root canal anatomic variations. The visualization of all canals is considered essential in endodontic therapy. The use of multi-correspondence analysis for statistics in endodontic research is a new approach as a prognostic tool. PMID:27764246

51. View of upper radar scanner switch in radar scanner ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

51. View of upper radar scanner switch in radar scanner building 105 from upper catwalk level showing emanating waveguides from upper switch (upper one-fourth of photograph) and emanating waveguides from lower radar scanner switch in vertical runs. - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

Geometric analysis of root canals prepared by four rotary NiTi shaping systems.

PubMed

Hashem, Ahmed Abdel Rahman; Ghoneim, Angie Galal; Lutfy, Reem Ahmed; Foda, Manar Yehia; Omar, Gihan Abdel Fatah

2012-07-01

A great number of nickel-titanium (NiTi) rotary systems with noncutting tips, different cross-sections, superior resistance to torsional fracture, varying tapers, and manufacturing method have been introduced to the market. The purpose of this study was to evaluate and compare the effect of 4 rotary NiTi preparation systems, Revo-S (RS; Micro-Mega, Besancon Cedex, France), Twisted file (TF; SybronEndo, Amersfoort, The Netherlands), ProFile GT Series X (GTX; Dentsply, Tulsa Dental Specialties, Tulsa, OK), and ProTaper (PT; Dentsply Maillefer, Ballaigues, Switzerland), on volumetric changes and transportation of curved root canals. Forty mesiobuccal canals of mandibular molars with an angle of curvature ranging from 25° to 40° were divided according to the instrument used in canal preparation into 4 groups of 10 samples each: group RS, group TF, group GTX, and group PT. Canals were scanned using an i-CAT CBCT scanner (Imaging Science International, Hatfield, PA) before and after preparation to evaluate the volumetric changes. Root canal transportation and centering ratio were evaluated at 1.3, 2.6, 5.2, and 7.8 mm from the apex. The significance level was set at P ≤ .05. The PT system removed a significantly higher amount of dentin than the other systems (P = .025). At the 1.3-mm level, there was no significant difference in canal transportation and centering ratio among the groups. However, at the other levels, TF maintained the original canal curvature recording significantly the least degree of canal transportation as well as the highest mean centering ratio. The TF system showed superior shaping ability in curved canals. Revo-S and GTX were better than ProTaper regarding both canal transportation and centering ability. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Efficacy of xylene and passive ultrasonic irrigation on remaining root filling material during retreatment of anatomically complex teeth.

PubMed

Cavenago, B C; Ordinola-Zapata, R; Duarte, M A H; del Carpio-Perochena, A E; Villas-Bôas, M H; Marciano, M A; Bramante, C M; Moraes, I G

2014-11-01

To evaluate the volume of remaining filling material in the mesial root canals of mandibular molars after root canal retreatment with different procedures performed sequentially. The mesial root canals of 12 human first mandibular molars were instrumented using the BioRace system until a size 25, .06 taper instrument. The mesial roots were filled with gutta-percha and AH-Plus using a vertical compaction technique. The specimens were scanned using microcomputed tomography with a voxel size of 16.8 μm before and after the retreatment procedures. To remove the filling material, the root canals were enlarged until the size 40, .04 taper instrument. The second step was to irrigate the root canals with xylene in the attempt to clean the root canals with paper points. In the third step, the passive ultrasonic irrigation technique (PUI) was performed using 2.5% sodium hypochlorite. The initial and residual filling material volume (mm(3) ) after each step was evaluated from the 0.5 to 6.5 mm level. The obtained data were expressed in terms of percentage of residual filling material. Statistical analysis was performed using the Friedman test (P < 0.05). All specimens had residual filling materials after all retreatment procedures. Passive ultrasonic irrigation enhanced the elimination of residual filling material in comparison with the mechanical stage at the 0.5-2.5 mm and 4.5-6.5 mm levels (P < 0.05). No significant difference was found between xylene and PUI methods. Filling materials were not completely removed by any of the retreatment procedures. The use of xylene and PUI after mechanical instrumentation enhanced removal of materials during endodontic retreatment of anatomically complex teeth. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Novel ultrasonic real-time scanner featuring servo controlled transducers displaying a sector image.

PubMed

Matzuk, T; Skolnick, M L

1978-07-01

This paper describes a new real-time servo controlled sector scanner that produces high resolution images and has functionally programmable features similar to phased array systems, but possesses the simplicity of design and low cost best achievable in a mechanical sector scanner. The unique feature is the transducer head which contains a single moving part--the transducer--enclosed within a light-weight, hand held, and vibration free case. The frame rate, sector width, stop action angle, are all operator programmable. The frame rate can be varied from 12 to 30 frames s-1 and the sector width from 0 degrees to 60 degrees. Conversion from sector to time motion (T/M) modes are instant and two options are available, a freeze position high density T/M and a low density T/M obtainable simultaneously during sector visualization. Unusual electronic features are: automatic gain control, electronic recording of images on video tape in rf format, and ability to post-process images during video playback to extract T/M display and to change time gain control (tgc) and image size.

An Ultrasonic Scanning Technique for In-Situ `Bowing' Measurement of Prototype Fast Breeder Reactor Fuel Sub-Assembly

NASA Astrophysics Data System (ADS)

Swaminathan, K.; Asokane, C.; Sylvia, J. I.; Kalyanasundaram, P.; Swaminathan, P.

2012-02-01

An ultrasonic under-sodium scanner has been developed for deployment in Prototype Fast Breeder Reactor (PFBR) which is in advanced stage of construction at Kalpakkam, India. Its purpose is to scan the above-core plenum for detection, if any, of displacement of sub-assemblies. During its burn-up in the reactor, the head of a Fuel Sub-Assembly (FSA) may undergo a lateral shift from its original position (called `bowing') due to the fast neutron induced damage on its structural material. A simple scanning technique has been developed for measuring the extent of bowing in-situ. This paper describes a PC-controlled mock-up of the scanner used to implement the scanning technique and the results obtained of scanning a mock-up FSA head under water. The details of the liquid-sodium proof transducer developed for use in the PFBR scanner and its performance are also discussed.

Effects of ultrasonic dental scaling on pulp vitality in dogs: an experimental study.

PubMed

Vérez-Fraguela, J L; Vives Vallés, M A; Ezquerra Calvo, L J

2000-06-01

We investigated whether dental pulpal damage is produced as a result of the application of an ultrasonic scaler commonly used in clinical veterinary dentistry. Using methods developed in preliminary studies, we examined six dogs. The radiographic thickness of the dentin and pulp cavity was measured. The ultrasonic scaler was applied to maxillary and mandibular premolar teeth for 30, 60, or 90 seconds, without the use of water as a coolant. The temperatures of the room, the pulp canal on untreated incisor teeth, the cheek, the gingival sulcus, and the dentin of the affected teeth were recorded using a probe with a thermistor attached to a resistivity meter and inserted in the dentin to a depth of 1 mm. Two weeks following scaling, the teeth were extracted for microscopic examination. In another dog serving as a control, the temperature of the dentin was increased to between 45 degrees C (113 degrees F) and 47 degrees C (117 degrees F) and the premolar teeth were removed for microscopic examination 15 days later. We concluded that the application of an uncooled ultrasonic scaler for 90 seconds did not increase the temperature of the dentin. However, damage comparable with acute pulpitis resulted as a consequence of the ultrasonic effect, similar to the effects produced by the 45-47 degrees C heat applied in the control animal.

Micro-computed Tomographic Analysis of Mandibular Second Molars with C-shaped Root Canals.

PubMed

Amoroso-Silva, Pablo Andrés; Ordinola-Zapata, Ronald; Duarte, Marco Antonio Hungaro; Gutmann, James L; del Carpio-Perochena, Aldo; Bramante, Clovis Monteiro; de Moraes, Ivaldo Gomes

2015-06-01

The goal of the present study was to evaluate the morphometric aspects of the internal anatomy of the root canal system of mandibular second molars with C-shaped canals. Fifty-two extracted second mandibular molars with C-shaped canals, fused roots, and radicular grooves were selected from a Brazilian population. The samples were scanned with a micro-computed tomographic scanner at a voxel size of 19.6 μm. The root canal cross sections were recorded as C1, C2, C3, and C4 root canal configurations according to the modified Melton classification. Morphometric parameters, including the major and minor diameters of the root canals, the aspect ratio, the roundness, and the tridimensional configuration (merging, symmetric, and asymmetric), were evaluated. The 3-dimensional reconstruction images of the teeth indicated an even distribution within the sample. The analysis of the prevalence of the different cross-sectional configurations of the C-shaped molars revealed that these were predominantly of the C4 and C3 configurations (1 mm from the apex) and the C1 and C2 configurations in the cervical third. According to the morphometric parameters, the C1 and the distal aspect of the C2 configurations exhibited the lowest roundness values and higher values for the area, major diameter, and aspect ratio in the apical third. Mandibular molars with C-shaped root canals exhibited similar distributions of symmetric, asymmetric, and merging type canals. The C1 configuration and the distal aspect of the C2 configuration exhibited the highest area values, low roundness values, and large apical diameters. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

3. ELEVATION. FROM SOUTH WITH CANAL PRISM. Canal Road ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. ELEVATION. FROM SOUTH WITH CANAL PRISM. - Canal Road Bridge, Canal Road spanning Delaware Canal Diversion, Locks 22 & 23 in Delaware Canal State Park in Williams Township, Raubsville, Northampton County, PA

Hot topics in biomedical ultrasound: ultrasound therapy and its integration with ultrasonic imaging

NASA Astrophysics Data System (ADS)

Everbach, E. Carr

2005-09-01

Since the development of biomedical ultrasound imaging from sonar after WWII, there has been a clear divide between ultrasonic imaging and ultrasound therapy. While imaging techniques are designed to cause as little change as possible in the tissues through which ultrasound propagates, ultrasound therapy typically relies upon heating or acoustic cavitation to produce a desirable therapeutic effect. Concerns over the increasingly high acoustic outputs of diagnostic ultrasound scanners prompted the adoption of the Mechanical Index (MI) and Thermal Index (TI) in the early 1990s. Therapeutic applications of ultrasound, meanwhile, have evolved from deep tissue heating in sports medicine to include targeted drug delivery, tumor and plaque ablation, cauterization via high intensity focused ultrasound (HIFU), and accelerated dissolution of blood clots. The integration of ultrasonic imaging and therapy in one device is just beginning, but the promise of improved patient outcomes is balanced by regulatory and practical impediments.

7. 'FLOW IN CANAL NO. 1, A JOINTLY USED CANAL, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

7. 'FLOW IN CANAL NO. 1, A JOINTLY USED CANAL, ON MAY 22 WHEN 210 SECOND FEET OF WATER WAS FLOWING. THIS WAS LATER INCREASED TO 240 SECOND FEET FOR A NUMBER OF DAYS TO SATISFY THE DEMANDS OF THE DRY GULCH COMPANY.' 1925 - Irrigation Canals in the Uinta Basin, Duchesne, Duchesne County, UT

Intercomparison of principal hydrometric instruments; Third phase, Evaluation of ultrasonic velocity meters for flow measurement in streams, canals, and estuaries

USGS Publications Warehouse

Melching, Charles S.; Meno, Michael W.

1998-01-01

As part of the World Meteorological Organization (WMO) project Intercomparison of Principal Hydrometric Instruments, Third Phase, a questionnaire was prepared by the U.S. Geological Survey (USGS) on the application of Ultrasonic Velocity Meters (UVM's) for flowmeasurement in streams, canals, and estuaries. In 1996, this questionnaire was distributed internationally by the WMO and USGS, and distributed within the United States by the USGS. Completed questionnaires were returned by 26 agencies in 7 countries (Canada, France, Germany, The Netherlands, Switzerland, the United Kingdom, and the United States). The completed questionnaires described geometric and streamflow conditions, system configurations, and reasons for applying UVM systems for 260 sites, thus providing information on the applicability of UVM systems throughout the world. The completed questionnaires also provided information on operational issues such as (1) methods used to determine and verify UVM ratings, (2) methods used to determine the mean flow velocity for UVM systems, (3) operational reliability of UVM systems, (4) methods to estimate missing data, (5) common problems with UVM systems and guidelines to mitigate these problems, and (6) personnel training issues. The completed questionnaires also described a few unique or novel applications of UVM systems. In addition to summarizing the completed questionnaires, this report includes a brief overview of UVM application and operation, and a short summary of current (1998) information from UVM system manufacturers regarding system cost and capabilities. On the basis of the information from the completed questionnaires and provided by the manufacturers, the general applicability of UVM systems is discussed. In the finalisation of this report the financial support provided by the US National Committee for Scientific Hydrology is gratefully acknowledged.

Comparison of apical extrusion of sodium hypochlorite using 4 different root canal irrigation techniques.

PubMed

İriboz, Emre; Bayraktar, Koral; Türkaydın, Dilek; Tarçın, Bilge

2015-03-01

We compared the apical extrusion of sodium hypochlorite delivered with a 27-G needle, self-adjusting file (SAF), passive ultrasonic irrigation, or the EndoVac system (SybronEndo, Orange, CA) during the instrumentation and final irrigation of root canals. Matched paired single-canal teeth were divided into 8 groups. The experimental groups were needle irrigation size #30 (NI30) and #50 (NI50), SAF size #30 (SAF30) and #50 (SAF50), passive ultrasonic irrigation size #30 (PUI30) and #50 (PUI50), and EndoVac size #30 (EV30) and #50 (EV50). Teeth were embedded in 0.2% agarose gel (pH = 7.4) containing 1 mL 0.1% m-Cresol purple (Sigma-Aldrich, St Louis, MO), which changes color at a pH level of 9.0. Root canals were irrigated with sodium hypochlorite and EDTA using 4 different techniques, and the amount of irrigant was controlled. Standardized digital photographs were taken 20 minutes after the first irrigant was used and were analyzed to determine the amount of extrusion (expressed as a percentage of total pixels). The amounts of apical extrusion obtained in the NI30, NI50, SAF30, SAF50, PUI30, PUI50, EV30, and EV50 groups were 30% (3/10), 50% (5/10), 20% (2/10), 70% (7/10), 40% (4/10), 40% (4/10), 10% (1/10), and 10% (1/10), respectively. The overall extrusion frequency, regardless of the apical preparation size, was 40% (8/20) for needle, 45% (9/20) for SAF, 40% (8/20) for ultrasonic irrigation, and 10% (2/20) for EndoVac. Although the SAF group showed more extrusion, the percentage of pixels was significantly higher in the needle irrigation group (P < .01). The EndoVac group showed significantly lower extrusion values than the other techniques in terms of the number of teeth and pixels (P < .05 and P < .01, respectively). The risk of apical extrusion is significantly lower with the EndoVac in comparison with the 3 other techniques. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

[The use of self-adapting system files (SAF) for controlling microbial biofilms of root canals in the treatment of apical periodontitis].

PubMed

Tsarev, V N; Mamedova, L A; Siukaeva, T N; Podporin, M S

The aim of this study was to conduct a clinical and laboratory study and evaluate the effectiveness of endodontic root canal treatment using a self-adapting files system (SAF) in the complex treatment of patients with chronic apical periodontitis. 3% sodium hypochlorite solution was used as irrigation agent in all groups which included 20 patients treated with conventional manual tools, 21 patients receiving treatment with ultrasonic activation of irrigant and 26 patients treated with SAF system. Root canal biofilm structure was studied by scanning electron microscopy (SEM) using a Quantum 3D microscope (USA). Clinical efficiency of the root canal treatment was assessed by complications frequency a year after treatment. SEM revealed the presence of high levels of microbial contamination of dentine tubules in the apical portion of the tooth. In standard method group the percentage of re-treatment and surgery was higher than in the studied groups. Use of SAF irrigation system was associated with a decrease in the number of identified pathogens. However, the study revealed high resistance of Enterococcus spp., Porphyromonas gingivalis, Candida albicans to all types of endodontic treatment, so the improvement of methods of root canal microbial biofilms removing need to be continued.

Evaluation of 4% Sodium Hypochlorite in eliminating Enterococcus faecalis from the Root Canal when Used with Three Irrigation Methods: An in vitro Study.

PubMed

Priyank, Harsh; Pandey, Vinisha; Bagul, Abhishek; Majety, Kishore Kumar; Verma, Parul; Choudhury, Basanta Kumar

2017-03-01

Endodontic treatment removes all pathogens, such as Enterococcus faecalis from pulp and root canals. The aim of this study is to assess the usefulness of sodium hypo-chlorite (NaOCl) in removing E. faecalis from the root canal used with three different irrigation methods. This study was conducted on freshly extracted maxillary incisors. After biomechanical preparation, root canals were injected with E. faecalis. Three groups were made which contained 30 teeth in each group; 2 mL of NaOCl solution was used for irrigation followed by agitation with K-files in group I; 2 mL of NaOCl solution was used for irrigation and ultrasonic agitation was done in group II. In group III, an alternate irrigation with NaOCl and 3% hydrogen peroxide was done. The fourth group (control) was irrigated with sterile saline solution. E. fae-calis bacteria were sampled to the root canals with paper points and were transferred to tubes that contained 5 mL of brain heart infusion broth. Tubes were incubated and the presence of broth turbidity was suggestive of bacteria remaining in the root canal. All three groups showed no statistically significant difference. However, difference existed between experimental groups and control groups. The author concluded that all three methods of application of NaOCl were effective in disinfecting the root canal than the saline solution. No single irrigant has 100% efficiency. Thus by this study, a best irrigating solution with maximum properties can be established.

Smear layer removal and canal cleanliness using different irrigation systems (EndoActivator, EndoVac, and passive ultrasonic irrigation): field emission scanning electron microscopic evaluation in an in vitro study.

PubMed

Mancini, Manuele; Cerroni, Loredana; Iorio, Lorenzo; Armellin, Emiliano; Conte, Gabriele; Cianconi, Luigi

2013-11-01

The purpose of this study was to evaluate the effectiveness of different irrigating methods in removing the smear layer at 1, 3, 5, and 8 mm from the apex of endodontic canals. Sixty-five extracted single-rooted human mandibular premolars were decoronated to a standardized length of 16 mm. Specimens were shaped to ProTaper F4 (Dentsply Maillefer, Ballaigues, Switzerland) and irrigated with 5.25% NaOCl at 37°C. Teeth were divided into 5 groups (2 control groups [n = 10] and 3 test groups [n = 15]) according to the final irrigant activation/delivering technique (ie, sonic irrigation, passive ultrasonic irrigation [PUI], or apical negative pressure). Root canals were then split longitudinally and observed by field emission scanning electron microscopy. The presence of debris and a smear layer at 1, 3, 5, and 8 mm from the apex was evaluated. Scores were analyzed by Kruskal-Wallis and Mann-Whitney U tests. The EndoActivator System (Dentsply Tulsa Dental Specialties, Tulsa, OK) was significantly more efficient than PUI and the control groups in removing the smear layer at 3, 5, and 8 mm from the apex. The EndoVac System (Discus Dental, Culver City, CA) removed statistically significantly more smear layer than all groups at 1, 3, 5, and 8 mm from the apex. At 5 and 8 mm from the apex, PUI and the EndoVac did not differ statistically significantly, but both performed statistically better than the control groups. In our study, none of the activation/delivery systems completely removed the smear layer from the endodontic dentine walls; nevertheless, the EndoActivator and EndoVac showed the best results at 3, 5, and 8 mm (EndoActivator) and 1, 3, 5, and 8 mm (EndoVac) from the apex. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Qualification of the RSRM field joint CF case-to-insulation bondline inspection using the Thiokol Corporation ultrasonic RSRM bondline inspection system

NASA Technical Reports Server (NTRS)

Cook, M.

1990-01-01

Qualification testing of Combustion Engineering's AMDATA Intraspect/98 Data Acquisition and Imaging System that applies to the redesigned solid rocket motor field joint capture feature case-to-insulation bondline inspection was performed. Testing was performed at M-111, the Thiokol Corp. Inert Parts Preparation Building. The purpose of the inspection was to verify the integrity of the capture feature area case-to-insulation bondline. The capture feature scanner was calibrated over an intentional 1.0 to 1.0 in. case-to-insulation unbond. The capture feature scanner was then used to scan 60 deg of a capture feature field joint. Calibration of the capture feature scanner was then rechecked over the intentional unbond to ensure that the calibration settings did not change during the case scan. This procedure was successfully performed five times to qualify the unbond detection capability of the capture feature scanner. The capture feature scanner qualified in this test contains many points of mechanical instability that can affect the overall ultrasonic signal response. A new generation scanner, designated the sigma scanner, should be implemented to replace the current configuration scanner. The sigma scanner eliminates the unstable connection points of the current scanner and has additional inspection capabilities.

High-Performance Acousto-Ultrasonic Scan System Being Developed

NASA Technical Reports Server (NTRS)

Roth, Don J.; Martin, Richard E.; Cosgriff, Laura M.; Gyekenyesi, Andrew L.; Kautz, Harold E.

2003-01-01

Acousto-ultrasonic (AU) interrogation is a single-sided nondestructive evaluation (NDE) technique employing separated sending and receiving transducers. It is used for assessing the microstructural condition and distributed damage state of the material between the transducers. AU is complementary to more traditional NDE methods, such as ultrasonic cscan, x-ray radiography, and thermographic inspection, which tend to be used primarily for discrete flaw detection. Throughout its history, AU has been used to inspect polymer matrix composites, metal matrix composites, ceramic matrix composites, and even monolithic metallic materials. The development of a high-performance automated AU scan system for characterizing within-sample microstructural and property homogeneity is currently in a prototype stage at NASA. This year, essential AU technology was reviewed. In addition, the basic hardware and software configuration for the scanner was developed, and preliminary results with the system were described. Mechanical and environmental loads applied to composite materials can cause distributed damage (as well as discrete defects) that plays a significant role in the degradation of physical properties. Such damage includes fiber/matrix debonding (interface failure), matrix microcracking, and fiber fracture and buckling. Investigations at the NASA Glenn Research Center have shown that traditional NDE scan inspection methods such as ultrasonic c-scan, x-ray imaging, and thermographic imaging tend to be more suited to discrete defect detection rather than the characterization of accumulated distributed micro-damage in composites. Since AU is focused on assessing the distributed micro-damage state of the material in between the sending and receiving transducers, it has proven to be quite suitable for assessing the relative composite material state. One major success story at Glenn with AU measurements has been the correlation between the ultrasonic decay rate obtained during AU

High-Performance Acousto-Ultrasonic Scan System Being Developed

NASA Technical Reports Server (NTRS)

Roth, Don J.; Martin, Richard E.; Cosgriff, Laura M.; Gyekenyesi, Andrew L.; Kautz, Harold E.

2003-01-01

Acousto-ultrasonic (AU) interrogation is a single-sided nondestructive evaluation (NDE) technique employing separated sending and receiving transducers. It is used for assessing the microstructural condition and distributed damage state of the material between the transducers. AU is complementary to more traditional NDE methods, such as ultrasonic cscan, x-ray radiography, and thermographic inspection, which tend to be used primarily for discrete flaw detection. Throughout its history, AU has been used to inspect polymer matrix composites, metal matrix composites, ceramic matrix composites, and even monolithic metallic materials. The development of a high-performance automated AU scan system for characterizing within-sample microstructural and property homogeneity is currently in a prototype stage at NASA. This year, essential AU technology was reviewed. In addition, the basic hardware and software configuration for the scanner was developed, and preliminary results with the system were described. Mechanical and environmental loads applied to composite materials can cause distributed damage (as well as discrete defects) that plays a significant role in the degradation of physical properties. Such damage includes fiber/matrix debonding (interface failure), matrix microcracking, and fiber fracture and buckling. Investigations at the NASA Glenn Research Center have shown that traditional NDE scan inspection methods such as ultrasonic c-scan, x-ray imaging, and thermographic imaging tend to be more suited to discrete defect detection rather than the characterization of accumulated distributed microdamage in composites. Since AU is focused on assessing the distributed microdamage state of the material in between the sending and receiving transducers, it has proven to be quite suitable for assessing the relative composite material state. One major success story at Glenn with AU measurements has been the correlation between the ultrasonic decay rate obtained during AU

System and method of reducing motion-induced noise in the optical detection of an ultrasound signal in a moving body of material

DOEpatents

Habeger, Jr., Charles C.; LaFond, Emmanuel F.; Brodeur, Pierre; Gerhardstein, Joseph P.

2002-01-01

The present invention provides a system and method to reduce motion-induced noise in the detection of ultrasonic signals in a moving sheet or body of material. An ultrasonic signal is generated in a sheet of material and a detection laser beam is moved along the surface of the material. By moving the detection laser in the same direction as the direction of movement of the sheet of material the amount of noise induced in the detection of the ultrasonic signal is reduced. The scanner is moved at approximately the same speed as the moving material. The system and method may be used for many applications, such in a paper making process or steel making process. The detection laser may be directed by a scanner. The movement of the scanner is synchronized with the anticipated arrival of the ultrasonic signal under the scanner. A photodetector may be used to determine when a ultrasonic pulse has been directed to the moving sheet of material so that the scanner may be synchronized the anticipated arrival of the ultrasonic signal.

A novel experimental approach to investigate the effect of different agitation methods using sodium hypochlorite as an irrigant on the rate of bacterial biofilm removal from the wall of a simulated root canal model.

PubMed

Mohmmed, Saif Alarab; Vianna, Morgana E; Penny, Matthew R; Hilton, Stephen T; Mordan, Nicola; Knowles, Jonathan C

2016-10-01

Root canal irrigation is an important adjunct to control microbial infection. This study aimed primarily to develop a transparent root canal model to study in situ Enterococcus faecalis biofilm removal rate and remaining attached biofilm using passive or active irrigation solution for 90s. The change in available chlorine and pH of the outflow irrigant were assessed. A total of forty root canal models (n=10 per group) were manufactured using 3D printing. Each model consisted of two longitudinal halves of an 18mm length simulated root canal with size 30 and taper 0.06. E. faecalis biofilms were grown on the apical 3mm of the models for 10days in Brain Heart Infusion broth. Biofilms were stained using crystal violet for visualization. The model halves were reassembled, attached to an apparatus and observed under a fluorescence microscope. Following 60s of 9mL of 2.5% NaOCl irrigation using syringe and needle, the irrigant was either left stagnant in the canal or activated using gutta-percha, sonic and ultrasonic methods for 30s. Images were then captured every second using an external camera. The residual biofilm percentages were measured using image analysis software. The data were analyzed using Kruskal-Wallis test and generalized linear mixed model. The highest level of biofilm removal was with ultrasonic agitation (90.13%) followed by sonic (88.72%), gutta-percha (80.59%), and passive irrigation group (control) (43.67%) respectively. All agitation groups reduced the available chlorine and pH of NaOCl more than that in the passive irrigation group. The 3D printing method provided a novel model to create a root canal simulation for studying and understanding a real-time biofilm removal under microscopy. Ultrasonic agitation of NaOCl left the least amount of residual biofilm in comparison to sonic and gutta-percha agitation methods. Copyright © 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Panama Canal : a new course for the canal

DOT National Transportation Integrated Search

1999-01-01

While the Panama Canal provides significant time savings, passage through this narrow waterway presents a host of challenges. Soon all canal pilots will have a new tool in their efforts to safely guide vessels through this difficult canal: a Communic...

Side scanner for supermarkets: a new scanner design standard

NASA Astrophysics Data System (ADS)

Cheng, Charles K.; Cheng, J. K.

1996-09-01

High speed UPC bar code has become a standard mode of data capture for supermarkets in the US, Europe, and Japan. The influence of the ergonomics community on the design of the scanner is evident. During the past decade the ergonomic issues of cashier in check-outs has led to occupational hand-wrist cumulative trauma disorders, in most cases causing carpal tunnel syndrome, a permanent hand injury. In this paper, the design of a side scanner to resolve the issues is discussed. The complex optical module and the sensor for aforesaid side scanner is described. The ergonomic advantages offer the old counter mounted vertical scanner has been experimentally proved by the industrial funded study at an independent university.

Design of signal reception and processing system of embedded ultrasonic endoscope

NASA Astrophysics Data System (ADS)

Li, Ming; Yu, Feng; Zhang, Ruiqiang; Li, Yan; Chen, Xiaodong; Yu, Daoyin

2009-11-01

Embedded Ultrasonic Endoscope, based on embedded microprocessor and embedded real-time operating system, sends a micro ultrasonic probe into coelom through the biopsy channel of the Electronic Endoscope to get the fault histology features of digestive organs by rotary scanning, and acquires the pictures of the alimentary canal mucosal surface. At the same time, ultrasonic signals are processed by signal reception and processing system, forming images of the full histology of the digestive organs. Signal Reception and Processing System is an important component of Embedded Ultrasonic Endoscope. However, the traditional design, using multi-level amplifiers and special digital processing circuits to implement signal reception and processing, is no longer satisfying the standards of high-performance, miniaturization and low power requirements that embedded system requires, and as a result of the high noise that multi-level amplifier brought, the extraction of small signal becomes hard. Therefore, this paper presents a method of signal reception and processing based on double variable gain amplifier and FPGA, increasing the flexibility and dynamic range of the Signal Reception and Processing System, improving system noise level, and reducing power consumption. Finally, we set up the embedded experiment system, using a transducer with the center frequency of 8MHz to scan membrane samples, and display the image of ultrasonic echo reflected by each layer of membrane, with a frame rate of 5Hz, verifying the correctness of the system.

27. VIEW OF TWIN FALLS MAIN CANAL HEADGATE WITH CANAL ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

27. VIEW OF TWIN FALLS MAIN CANAL HEADGATE WITH CANAL BRIDGE IN DISTANCE; LOOKING SOUTHWEST. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

Analyzing endosonic root canal file oscillations: an in vitro evaluation.

PubMed

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.

Anatomic study on mental canal and incisive nerve canal in interforaminal region in Chinese population.

PubMed

Xu, Yun; Suo, Ning; Tian, Xiufen; Li, Fei; Zhong, Guangxin; Liu, Xiaoran; Bao, Yongxing; Song, Tao; Tian, Hua

2015-08-01

This study was aimed to detect the positions of mental canal and incisive nerve canal as well as the prolongation of mandibular canal in interforaminal region in Chinese population to supply the reference data of the surgical safe zone in chin for clinicians. A total of 80 formalin-fixed semi-mandibles of Chinese adult cadavers were dissected, the positions and courses of mental canal and incisive nerve canal as well as the prolongation of mandibular canal in interforaminal region were measured. The mental foramina were present in all cases (100 %), and most of them were located below 2nd premolar (58.75 %). Accessory mental foramina were observed in 5 %. The anterior end of mandibular canal, extending along the course of 7.37 ± 1.10 mm above the lower border of mandible to interforaminal region about 3.54 ± 0.70 mm medial to the mental foramen, most often ended below between the two premolars (73.75 %), where it continued as the incisive nerve canal (100 %) and the mental canal (96.25 %). Mental canal, with the wall formed by compact bone, being 2.60 ± 0.60 mm in diameter and 4.01 ± 1.20 mm in length, opened into mental foramen. Incisive nerve canal, with the wall formed by thin compact bone and/or partly or completely by spongy bone, being 1.76 ± 0.27 mm in diameter and 24.87 ± 2.23 mm in length, extended to the incisor region along the course of 9.53 ± 1.43 mm above the lower border of mandible, and most often ended below the lateral incisor (70.00 %). This research recommended for chin operations in Chinese population: the surgical safe zone could be set in the region about over 4 mm anterior to the mental foramen, and over 12 mm above inferior border of mandible for anterior alveolar surgery, or within 9 mm above inferior border of mandible for genioplasty.

Compensation for the signal processing characteristics of ultrasound B-mode scanners in adaptive speckle reduction.

PubMed

Crawford, D C; Bell, D S; Bamber, J C

1993-01-01

A systematic method to compensate for nonlinear amplification of individual ultrasound B-scanners has been investigated in order to optimise performance of an adaptive speckle reduction (ASR) filter for a wide range of clinical ultrasonic imaging equipment. Three potential methods have been investigated: (1) a method involving an appropriate selection of the speckle recognition feature was successful when the scanner signal processing executes simple logarithmic compressions; (2) an inverse transform (decompression) of the B-mode image was effective in correcting for the measured characteristics of image data compression when the algorithm was implemented in full floating point arithmetic; (3) characterising the behaviour of the statistical speckle recognition feature under conditions of speckle noise was found to be the method of choice for implementation of the adaptive speckle reduction algorithm in limited precision integer arithmetic. In this example, the statistical features of variance and mean were investigated. The third method may be implemented on commercially available fast image processing hardware and is also better suited for transfer into dedicated hardware to facilitate real-time adaptive speckle reduction. A systematic method is described for obtaining ASR calibration data from B-mode images of a speckle producing phantom.

Endodontic management of mesiobuccal-2 canal in four-rooted and five-canalled mandibular third molar.

PubMed

Garg, Amit Kumar; Bhardwaj, Anuj; Mantri, Vijay R; Agrawal, Neha

2014-05-01

A case of unusual Root morphology is presented to demonstrate anatomic variations in mandibular third molar. The most common configuration of mandibular third molar is two Roots and three canals; however they may have many different combinations. Endodontic treatment was performed in mandibular third molar having aberrant anatomy. Four Root canal orifices were located with the aid of dental operating microscope (DOM) and three separate Roots were diagnosed with radiographs. Spiral computed tomography (SCT) showed the presence of an extra canal and extra Root, indicating a rare anatomic configuration. Looking for additional canals and Roots are important part of successful endodontics, as the knowledge of their existence enable clinicians to treat a case successfully that otherwise might end in failure. The use of DOM and SCT in this case greatly contributed toward making a confirmatory diagnosis and successful endodontic treatment of four-rooted and five-canalled mandibular third molar. Variation in Root canal anatomy is very common. Knowledge of these variations is very essential for successful Root canal outcome, inability to do so can lead to missed canals and failures. Hence, thorough knowledge of Root canal anatomy and advances in diagnostic aids are essential.

[Evaluation of postoperative pain comparing manual and ultrasonic endodontic instrumentation in patients with cleft lip and palate].

PubMed

Brosco, H B; Pimentel, P A; Lacerda, A G; Nishiyama, C K; de Moraes, I G

1989-01-01

Our purpose was to compare incidence of post-surgical pain associated to the endodontic therapy where the instrumentation on the root canal was performed by the method of Marshall & Pappin and the method of Marshall & Pappin complemented by the ultrasonic. Seventy patients with only one tooth needing endodontic treatment were treated by one of the methods and, posteriorly, evaluated. The endodontic treatment was performed at one time and from the seventy teeth, thirty have been instrumented by the manual method complemented by the ultrasonic and forty by the manual instrumentation. The patients were clinically controlled after the endodontic treatment was finished during periods of 24, 48 and 72 hours to evaluate their post-surgical condition. The results suggest that were no statistically significant differences (p less than 0.05) in the incidence of pain between the employed methods or according to the pulpar semiologic condition in any of the observed periods. However, we have realized that there was a tendency for a smaller percentage of a postoperative pain in those cases of necropulpectamy treated by the endosonic ultrasonic synergistic system. In those cases of biopulpectomy this has been not observed.

Evaluation of the Amount of Debris extruded apically by using Conv-entional Syringe, Endovac and Ultrasonic Irrigation Technique: An In Vitro Study

PubMed Central

Tambe, Varsha H; Nagmode, Pradnya S; Vishwas, Jayshree R; P, Saujanya K; Angadi, Prabakar; Ali, Fareedi Mukram

2013-01-01

Background: To compare the amount of debris extruded apically by using conventional syringe, Endovac & Ultrasonic irrigation. Materials & Methods: Thirty freshly extracted mandibular premolars were selected, working length was determined and mounted in a debris and collection apparatus. The canals were prepared. After each instrument change, 1 ml. of 3% sodium hypochlorite was used as irrigation. Debris extruded apically by using conventional syringe, endovac& ultrasonic irrigation tech, was measured using the electronic balance to determine its weight and statistical analysis was performed. The mean difference between the groups was determined using statistical analysis within the groups &between the groups for equal variances. Results: Among all the groups, significantly less debris were found apically in the Endovac group (0.96) compared to conventional and ultrasonic group (1.23) syringe. Conclusion: The present study showed that endovac system extrudes less amount of debris apically as compared to ultrasonic followed by conventional so incidence of flare up can be reduce by using endovac irrigation system. How to cite this article: Tambe V H, Nagmode P S, Vishwas J R, Saujanya K P, Angadi P, Ali F M. Evaluation of the Amount of Debris extruded apically by using Conventional Syringe, Endovac and Ultrasonic Irrigation Technique: An In Vitro Study. J Int Oral Health 2013; 5(3):63-66. PMID:24155604

2. CANAL BOAT ENTERING THE DELAWARE CANAL FROM OF THE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. CANAL BOAT ENTERING THE DELAWARE CANAL FROM OF THE LEHIGH RIVER. BOATS COULD BE FERRIED ACROSS THE DELAWARE RIVER TO THE MORRIS CANAL BY A CABLE SUPPORTED TROLLEY. - Morris Canal, Phillipsburg, Warren County, NJ

[Analysis of different endodontic sealers and strategies of root canal irrigation on the bond strength of fiber posts].

PubMed

Zhu, Shujin; Liu, Cuiling; Zheng, Zheng; Yang, Liyuan; Gao, Xu

2015-06-01

To evaluate the influence of eugenol-containing and resin-containing endodontic sealers on the bond strength of fiber posts using different strategies of root canal irrigation. Forty-eight mandibular premolars were endodontically treated. The specimens were randomly assigned into two groups according to different endodontic sealers. Group A used Endofil (eugenol-containing endodontic sealer), and group B used AH-plus (resin-containing endodontic sealer). After post space preparation, each group was randomly assigned into three subgroups according to the strategies of root canal irrigation (eight premolars in each subgroup). Group Al and B1: 0.9%NaCl irrigation; Group A2 and B2: 17% ethylene diamine tetraacetic acid (EDTA)+5.25%NaClO+0.9%NaCl irrigation; Group A3 and B3: ultrasonic agitation associated with 1 7%EDTA+5.25%NaClO+0.9%NaCl. One week after the cementation of fiber posts using RelyX™ Unicem, a push-out test was performed to measure the bond strength of the posts. The microstructure of the root canal surface was examined under scanning electron microscope (SEM). The bond strengths of the six groups were as follows: Al (7.96±2.23) MPa, A2 (9.95±2.89) MPa, A3 (18.88±3.69) MPa, B1 (11.41±3.71) MPa, B2 (14.00±4.04) MPa, and B3 (19.14±3.27) MPa. Statistical analysis revealed a significant interaction between the different endodontic sealers and the strategies of root canal irrigation (P<0.05). Lower bond strength was found in group Al but not in group BI (P<0.05), and the same result was revealed when comparing group A2 and B2. No significant difference was observed between group A3 and B3 (P>0.05). SEM showed that the root canal in group A3 and B3 achieved the cleanest surface with nearly all dentine tubules opened. The eugenol-containing endodontic sealer can impair the bond strength of fiber posts compared with the resin-containing sealer when the root canal is irrigated by 0.9% NaCl or 17%EDTA+5.25%NaClO+0.9%NaC. No difference was observed between

Feasibility on Ultrasonic Velocity using Contact and Non-Contact Nondestructive Techniques for Carbon/Carbon Composites

NASA Astrophysics Data System (ADS)

Im, K. H.; Chang, M.; Hsu, D. K.; Song, S. J.; Cho, H.; Park, J. W.; Kweon, Y. S.; Sim, J. K.; Yang, I. Y.

2007-03-01

Advanced materials are to be required to have specific functions associated with extremely environments. One of them is carbon/carbon(C/C) composite material, which has obvious advantages over conventional materials. The C/Cs have become to be utilized as parts of aerospace applications and its low density, high thermal conductivity and excellent mechanical properties at elevated temperatures make it an ideal material for aircraft brake disks. Because of permeation of coupling medium such as water, it is desirable to perform contact-less nondestructive evaluation to assess material properties and part homogeneity. In this work, a C/C composite material was characterized with non-contact and contact ultrasonic methods using a scanner with automatic-data acquisition function. Also through transmission mode was performed because of the main limitation for air-coupled transducers, which is the acoustic impedance mismatch between most materials and air. Especially ultrasonic images and velocities for C/C composite disk brake were compared and found to be consistent to some degree with the non-contact and contact ultrasonic measurement methods. Low frequency through-transmission scans based on both amplitude of the ultrasonic pulse was used for mapping out the material property inhomogeneity. Measured results were compared with those obtained by the dry-coupling ultrasonic UT system and through transmission method in immersion. Finally, feasibility has been found to measure and compare ultrasonic velocities of C/C composites with using the contact/noncontact peak-delay measurement method based on the pulse overlap method.

Decreased levels of matrix metalloproteinase-2 in root-canal exudates during root canal treatment.

PubMed

Pattamapun, Kassara; Handagoon, Sira; Sastraruji, Thanapat; Gutmann, James L; Pavasant, Prasit; Krisanaprakornkit, Suttichai

2017-10-01

To determine the matrix metalloproteinase-2 (MMP-2) levels in root-canal exudates from teeth undergoing root-canal treatment. The root-canal exudates from six teeth with normal pulp and periradicular tissues that required intentional root canal treatment for prosthodontic reasons and from twelve teeth with pulp necrosis and asymptomatic apical periodontitis (AAP) were sampled with paper points for bacterial culture and aspirated for the detection of proMMP-2 and active MMP-2 by gelatin zymography and the quantification of MMP-2 levels by ELISA. By gelatin zymography, both proMMP-2 and active MMP-2 were detected in the first collection of root-canal exudates from teeth with pulp necrosis and AAP, but not from teeth with normal pulp, and their levels gradually decreased and disappeared at the last collection. Consistently, ELISA demonstrated a significant decrease in MMP-2 levels in the root-canal exudates of teeth with pulp necrosis and AAP following root canal procedures (p<0.05). Furthermore, the MMP-2 levels were significantly lower in the negative bacterial culture than those in the positive bacterial culture (p<0.001). The levels of MMP-2 in root-canal exudates from teeth with pulp necrosis and AAP were gradually reduced during root canal procedures. Future studies are required to determine if MMP-2 levels may be used as a biomolecule for the healing of apical lesions, similar to the clinical application of MMP-8 as a biomarker. Copyright © 2017 Elsevier Ltd. All rights reserved.

Canal transportation after root canal instrumentation: a comparative study with computed tomography.

PubMed

Hartmann, Mateus Silveira Martins; Barletta, Fernando Branco; Camargo Fontanella, Vânia Regina; Vanni, José Roberto

2007-08-01

This in vitro study used computed tomography (CT) to compare the occurrence of canal transportation in the apical third of mesiobuccal canals in maxillary molars instrumented with 3 techniques. Sixty teeth were assigned to 3 groups (n = 20), and the root canals were instrumented as follows: Group 1, hand instrumentation with K-files; Group 2, K-files coupled to an oscillatory system powered by an electric engine; Group 3, ProTaper NiTi rotary system powered by an electric engine. To compare the canal transportation produced by the different techniques, preinstrumentation and postinstrumentation 3-dimensional CT images were obtained from root cross-sections of the region located 3 mm short of the apical foramen of each root canal. The CT scans were exported to Adobe Photoshop software, and the initial and final images were superimposed to detect the root canal wall differences between them. Canal transportation was measured by the distance between the prepared canal center and the anatomic canal center. The manual technique produced lesser canal transportation (0.10 mm) than the oscillatory and rotary techniques (0.37 and 0.22 mm, respectively); this difference was statistically significant (P=.021). All studied techniques produced canal transportation.

14. MAIN CANAL CANAL CHECKGATES, JUST BELOW DARK CANYON ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

14. MAIN CANAL - CANAL CHECKGATES, JUST BELOW DARK CANYON SIPHON, VIEW TO NORTHEAST - Carlsbad Irrigation District, Main Canal, 4 miles North to 12 miles Southeast of Carlsbad, Carlsbad, Eddy County, NM

Root canal irrigants

PubMed Central

Kandaswamy, Deivanayagam; Venkateshbabu, Nagendrababu

2010-01-01

Successful root canal therapy relies on the combination of proper instrumentation, irrigation, and obturation of the root canal. Of these three essential steps of root canal therapy, irrigation of the root canal is the most important determinant in the healing of the periapical tissues. The primary endodontic treatment goal must thus be to optimize root canal disinfection and to prevent reinfection. In this review of the literature, various irrigants and the interactions between irrigants are discussed. We performed a Medline search for English-language papers published untill July 2010. The keywords used were ‘root canal irrigants’ and ‘endodontic irrigants.’ The reference lists of each article were manually checked for additional articles of relevance. PMID:21217955

Comparison between the use of an ultrasonic tip and a microhead handpiece in periradicular surgery: a prospective randomised trial.

PubMed

Shearer, Jane; McManners, Joseph

2009-07-01

Innovations in periradicular surgery for failed treatment of orthograde root canal disease have been well-documented. We know of no prospective studies that have compared success rates of conventional methods with these presumed advances. In this prospective randomised trial we compare the use of an ultrasonic retrotip with a microhead bur in the preparation of a retrograde cavity. Outcome was estimated clinically by estimation of pain, swelling, and sinus, and radiographically by looking at infill of bone and retrograde root filling 2 weeks and 6 months postoperatively. Both methods used other surgical techniques including microinstruments to place the retrograde root filling. The success rate of the ultrasonic method was higher (all patients, n=26) than that of the microhead method (n=19 of 21). A larger study with longer follow up is required to consolidate this evidence.

8. BLACK RIVER CANAL LOOKING DOWN CANAL WITH LATERAL ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

8. BLACK RIVER CANAL - LOOKING DOWN CANAL WITH LATERAL TURNOUT NO. 1 ON THE RIGHT. VIEW TO THE SOUTHEAST - Carlsbad Irrigation District, Black River Canal, 15 miles Southeast of Carlsbad near Malaga, Carlsbad, Eddy County, NM

9. BLACK RIVER CANAL CANAL (RIGHT), DISCHARGE GATE (BACKGROUND), ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

9. BLACK RIVER CANAL - CANAL (RIGHT), DISCHARGE GATE (BACKGROUND), FARMER'S TURNOUT (LEFT), AND LATERAL NO. 14 (FOREGROUND). VIEW TO SOUTHEAST - Carlsbad Irrigation District, Black River Canal, 15 miles Southeast of Carlsbad near Malaga, Carlsbad, Eddy County, NM

Effect of Er:YAG laser-activated irrigation solution on Enterococcus Faecalis biofilm in an ex-vivo root canal model.

PubMed

Sahar-Helft, Sharonit; Stabholtz, Adam; Moshonov, Joshua; Gutkin, Vitaly; Redenski, Idan; Steinberg, Doron

2013-07-01

Abstract Objective: The purpose of this study was to evaluate mineral content and surface morphology of root canals coated with Enterococcus faecalis biofilm after treatment with several endodontic irrigation solutions, with and without Er:YAG laser-activated irrigation (LAI). LAI has been introduced as a powerful method for root canal irrigation resulting in smear-layer removal from the root canal wall. Distal and palatal roots from 60 freshly extracted human molars were used in this study. The coronal of each tooth was removed. Roots were split longitudinally and placed in an ultrasonic bath to remove the smear layer, creating conditions for the formation of E. faecalis biofilm. After incubation, the two halves were reassembled in impression material to simulate clinical conditions. Specimens were divided into two main groups: roots rinsed with irrigation solutions and roots subjected to laser irradiation combined with irrigation solutions. Solutions tested were 2% chlorhexidine and 17% ethylenediaminetetraacetic acid (EDTA) and saline. Surface morphology: 17% EDTA irrigant solution combined with Er:YAG laser showed the best results for removing bacteria from the root canal walls. Chemical analysis: all samples treated with combined laser irradiation and irrigation solution had low surface levels of Ca compared with samples treated with irrigation alone. The Ca/P ratio was highest in the laser-EDTA group. Overall, mineral changes caused by laser with irrigation solutions were minimal, and statistically nonsignificant. In vitro irrigation solutions, combined with Er:YAG laser irradiation, were effective in removing E. faecalis biofilm from root canal walls. Irrigation solutions without laser irradiation were less effective, leaving a layer of biofilm on the dentin surface.

Canals

ERIC Educational Resources Information Center

Winkleman, Michael

1974-01-01

In the mid-1800's, the canal system in the U.S. was thriving. But, by the end of that century, roads and railways had replaced these commercial thoroughfares. Renewed interest in the abandoned canals is now resulting in renovation and ecological site development in Pennsylvania and New Jersey. (MA)

A comparative evaluation of the increase in root canal surface area and canal transportation in curved root canals by three rotary systems: A cone-beam computed tomographic study

PubMed Central

Prasanthi, Nalam NVD; Rambabu, Tanikonda; Sajjan, Girija S; Varma, K Madhu; Satish, R Kalyan; Padmaja, M

2016-01-01

Aim: The aim of this study was to measure the increase in root canal surface area and canal transportation after biomechanical preparation at 1, 3, and 5 mm short of the apex with three different rotary systems in both continuous rotary and reciprocating rotary motions. Materials and Methods: Sixty freshly extracted human mandibular molars with mesial root canal curvatures between 20° and 30° were included in the study. Teeth were randomly distributed into three groups (n = 20). Biomechanical preparations were done in all the mesial canals. In Group 1, instrumentation was done with ProTaper universal rotary files, Group 2, with K3XF rotary files, and Group 3, with LSX rotary files. Each group was further subdivided into subgroups A and B (n = 10) where instrumentation was done by continuous rotary and reciprocating rotary techniques, respectively. Increase in root canal surface area and canal transportation was measured using the preoperative and postoperative cone-beam computed tomography scans. Statistical Analysis: The data were analyzed by one-way ANOVA followed by Tukey pairwise multiple comparison tests. Results: Increase in root canal surface area was significantly more (P < 0.05) in ProTaper and K3XF groups when compared to LSX group. Canal transportation was significantly more (P < 0.05) in ProTaper group when compared to K3XF and LSX groups. There was no significant difference (P > 0.05) in increase of root canal surface area and canal transportation between continuous rotary and reciprocating rotary techniques for ProTaper Universal, K3XF and LSX groups. Conclusion: LSX rotary system showed minimal increase of root canal surface area and minimal canal transportation when compared to ProTaper and K3XF rotary systems. PMID:27656062

Vehicle Tracking for an Evasive Manoeuvres Assistant Using Low-Cost Ultrasonic Sensors

PubMed Central

Jiménez, Felipe; Naranjo, José E.; Gómez, Oscar; Anaya, José J.

2014-01-01

Many driver assistance systems require knowledge of the vehicle environment. As these systems are increasing in complexity and performance, this knowledge of the environment needs to be more complete and reliable, so sensor fusion combining long, medium and short range sensors is now being used. This paper analyzes the feasibility of using ultrasonic sensors for low cost vehicle-positioning and tracking in the lane adjacent to the host vehicle in order to identify free areas around the vehicle and provide information to an automatic avoidance collision system that can perform autonomous braking and lane change manoeuvres. A laser scanner is used for the early detection of obstacles in the direction of travel while two ultrasonic sensors monitor the blind spot of the host vehicle. The results of tests on a test track demonstrate the ability of these sensors to accurately determine the kinematic variables of the obstacles encountered, despite a clear limitation in range. PMID:25460817

Vehicle tracking for an evasive manoeuvres assistant using low-cost ultrasonic sensors.

PubMed

Jiménez, Felipe; Naranjo, José E; Gómez, Oscar; Anaya, José J

2014-11-28

Many driver assistance systems require knowledge of the vehicle environment. As these systems are increasing in complexity and performance, this knowledge of the environment needs to be more complete and reliable, so sensor fusion combining long, medium and short range sensors is now being used. This paper analyzes the feasibility of using ultrasonic sensors for low cost vehicle-positioning and tracking in the lane adjacent to the host vehicle in order to identify free areas around the vehicle and provide information to an automatic avoidance collision system that can perform autonomous braking and lane change manoeuvres. A laser scanner is used for the early detection of obstacles in the direction of travel while two ultrasonic sensors monitor the blind spot of the host vehicle. The results of tests on a test track demonstrate the ability of these sensors to accurately determine the kinematic variables of the obstacles encountered, despite a clear limitation in range.

The power of the bubble: comparing ultrasonic and laser activated irrigation

NASA Astrophysics Data System (ADS)

De Moor, Roeland J. G.; Meire, Maarten A.; Verdaasdonk, Rudolf M.

2014-01-01

The major problem of irrigation is the fluid motion within the confined geometry of the root canal : efficient dispersion of the liquid is difficult, conventional irrigation is limited due to the absence of turbulence over much of the canal volume, vapour lock may limit apical cleaning and disinfection, there is also a stagnation plane beyond the needle tip. The best way to improve irrigant penetration and biofilm removal is achieved by means of the agitation of the fluid. Today ultrasonic activation appears to be the best way to activate and potentiate irrigants among the present-day used means and marketed systems. Another way to activate irrigation solutions is the use of lasers: laser activated irrigation or photon-initiated acoustic streaming have been investigated. Based on present-day research it appears that the efficacy of laser activation (especially with Erbium lasers) can be more efficient thanks to the induction of specific cavitation phenomena and acoustic streaming. Other wavelengths are now explored to be used for laser activated irrigation.

Space-multiplexed optical scanner.

PubMed

Riza, Nabeel A; Yaqoob, Zahid

2004-05-01

A low-loss two-dimensional optical beam scanner that is capable of delivering large (e.g., > 10 degrees) angular scans along the elevation as well as the azimuthal direction is presented. The proposed scanner is based on a space-switched parallel-serial architecture that employs a coarse-scanner module and a fine-scanner module that produce an ultrahigh scan space-fill factor, e.g., 900 x 900 distinguishable beams in a 10 degrees (elevation) x 10 degrees (azimuth) scan space. The experimentally demonstrated one-dimensional version of the proposed scanner has a supercontinuous scan, 100 distinguishable beam spots in a 2.29 degrees total scan range, and 1.5-dB optical insertion loss.

An in vitro evaluation of various irrigation techniques for the removal of double antibiotic paste from root canal surfaces

PubMed Central

GOKTURK, Hakan; OZKOCAK, Ismail; BUYUKGEBİZ, Fevzi; DEMİR, Osman

2016-01-01

ABSTRACT Objective The aim of this study was to investigate the effectiveness of conventional syringe irrigations, passive ultrasonic irrigation (PUI), Vibringe, CanalBrush, XP-endo Finisher, and laser-activated irrigation (LAI) systems in removing double antibiotic paste (DAP) from root canals. Material and Methods One hundred five extracted single-rooted teeth were instrumented. The roots were split longitudinally. Three standard grooves were created and covered with DAP. The roots were distributed into seven groups: Group 1, beveled needle irrigation; Group 2, double side-vented needle irrigation; Group 3, CanalBrush; Group 4, XP-endo Finisher; Group 5, Vibringe; Group 6, PUI; Group 7, LAI. The amount of remaining DAP was scored under a stereomicroscope. Results Group 4, Group 6, and Group 7 removed significantly more DAP than the other protocols in the coronal region. Group 7 was more efficient in the middle region; however, no significant difference was found between Group 7 and Group 6. No differences were found between groups in the apical region either, except for the comparisons between groups 7 and 2, and groups 2 and 3. Conclusions None of the investigated protocols were able to completely remove the DAP from the grooves. The Vibringe and XP-endo Finisher systems showed results similar to those of conventional needle irrigation. PMID:28076461

Study of ultrasonic thermometry based on ultrasonic time-of-flight measurement

NASA Astrophysics Data System (ADS)

Jia, Ruixi; Xiong, Qingyu; Wang, Lijie; Wang, Kai; Shen, Xuehua; Liang, Shan; Shi, Xin

2016-03-01

Ultrasonic thermometry is a kind of acoustic pyrometry and it has been evolving as a new temperature measurement technology for various environment. However, the accurate measurement of the ultrasonic time-of-flight is the key for ultrasonic thermometry. In this paper, we study the ultrasonic thermometry technique based on ultrasonic time-of-flight measurement with a pair of ultrasonic transducers for transmitting and receiving signal. The ultrasonic transducers are installed in a single path which ultrasonic travels. In order to validate the performance of ultrasonic thermometry, we make a contrast about the absolute error between the measured temperature value and the practical one. With and without heater source, the experimental results indicate ultrasonic thermometry has high precision of temperature measurement.

A study of PC-based ultrasonic goniometer system of surface properties and characterization of materials

NASA Astrophysics Data System (ADS)

Sani, S.; Saad, M. H. Md; Jamaludin, N.; Ismail, M. P.; Mohd, S.; Mustapha, I.; Masenwat, N. A.; Tengku Amran, T. S.; Megat Ahmad, M. H. A.

2018-01-01

This paper discussed the design and development of a portable PC-based ultrasonic goniometer system that can be used to study material properties using ultrasonic wave. The system utilizes an ultrasonic pulse-receiver card model attached to computer notebook for signal display. A new specific software package (GoNIO) was developed to control the operation of the scanner, displaying the data and analyze characteristics of materials. System testing was carried out using samples with cubic dimension of about 10 mm x 20 mm x 30 mm. This size allows the sample to be fitted into the goniometer specimen holder and immersed in a liquid during measurement. The sample was rotated from incident angle of 0° to 90° during measurement and the amplitude reflected signals were recorded at every one degree of rotation. Immersion transducers were used to generate and receive the ultrasounds that pass through the samples. Longitudinal, shear and Rayleigh wave measurements were performed on the samples to determine the Dynamic Young’s Modulus. Results of measurements are explained and discussed.

Dual mode scanner-tracker

NASA Astrophysics Data System (ADS)

Mongeon, R. J.

1984-11-01

The beam of a laser radar is moved over the field of view by means of a pair of scanner/trackers arranged in cascade along the laser beam. One of the scanner/trackers operates at high speed, with high resolution and a wide field and is located in the demagnified portion of the laser beam. The two scanner/trackers complement each other to achieve high speed, high resolution scanning as well as tracking of moving targets. A beam steering telescope for an airborne laser radar which incorporates the novel dual mode scanner/tracker is also shown. The other scanner/tracker operates at low speed with low resolution and a wide field and is located in the magnified portion of the laser beam.

Comparison of canal transportation in simulated curved canals prepared with ProTaper Universal and ProTaper Gold systems

PubMed Central

Muniz, Brenda Leite; Pires, Frederico; Belladonna, Felipe Gonçalves; Neves, Aline Almeida; Souza, Erick Miranda; De-Deus, Gustavo

2016-01-01

Objectives The purpose of this study was to assess the ability of ProTaper Gold (PTG, Dentsply Maillefer) in maintaining the original profile of root canal anatomy. For that, ProTaper Universal (PTU, Dentsply Maillefer) was used as reference techniques for comparison. Materials and Methods Twenty simulated curved canals manufactured in clear resin blocks were randomly assigned to 2 groups (n = 10) according to the system used for canal instrumentation: PTU and PTG groups, upto F2 files (25/0.08). Color stereomicroscopic images from each block were taken exactly at the same position before and after instrumentation. All image processing and data analysis were performed with an open source program (FIJI). Evaluation of canal transportation was obtained for two independent canal regions: straight and curved levels. Student's t test was used with a cut-off for significance set at α = 5%. Results Instrumentation systems significantly influenced canal transportation (p < 0.0001). A significant interaction between instrumentation system and root canal level (p < 0.0001) was found. PTU and PTG systems produced similar canal transportation at the straight part, while PTG system resulted in lower canal transportation than PTU system at the curved part. Canal transportation was higher at the curved canal portion (p < 0.0001). Conclusions PTG system produced overall less canal transportation in the curved portion when compared to PTU system. PMID:26877984

Digital ultrasonics signal processing: Flaw data post processing use and description

NASA Technical Reports Server (NTRS)

Buel, V. E.

1981-01-01

A modular system composed of two sets of tasks which interprets the flaw data and allows compensation of the data due to transducer characteristics is described. The hardware configuration consists of two main units. A DEC LSI-11 processor running under the RT-11 sngle job, version 2C-02 operating system, controls the scanner hardware and the ultrasonic unit. A DEC PDP-11/45 processor also running under the RT-11, version 2C-02, operating system, stores, processes and displays the flaw data. The software developed the Ultrasonics Evaluation System, is divided into two catagories; transducer characterization and flaw classification. Each category is divided further into two functional tasks: a data acquisition and a postprocessor ask. The flaw characterization collects data, compresses its, and writes it to a disk file. The data is then processed by the flaw classification postprocessing task. The use and operation of a flaw data postprocessor is described.

[Continuous observation of canal aberrations in S-shaped simulated root canal prepared by hand-used ProTaper files].

PubMed

Xia, Ling-yun; Leng, Wei-dong; Mao, Min; Yang, Guo-biao; Xiang, Yong-gang; Chen, Xin-mei

2009-08-01

To observe the formation of canal aberrations in S-shaped root canals prepared by every file of hand-used ProTaper. Fifteen S-shaped simulated resin root canals were selected. Each root canal was prepared by every file of hand-used ProTaper following the manufacturer instruction. The images of canals prepared by S1, S2, F1, F2 and F3 were taken and stored, which were divided into group S1, S2, F1, F2 and F3. One image of canal unprepared was superposed with the images of the same root canal in these five groups respectively to observe the types and number of canal aberrations, which included unprepared area, danger zone, ledge, elbow, zip and perforation. SPSS12.0 software pakage was used for Fisher's exact probabilities in 2x2 table. Unprepared area decreased following preparation by every file of ProTaper, but it still existed when the canal preparation was finished. The incidence of danger zone, elbow and zip in group F1 was 15/15, 11/15, 4/15, respectively, which was significantly higher than that in group S2(2/15,0,0) (P<0.001). Ledge appeared after prepared by F2, and increased sharply in group F3. None perforation was found in all groups. The incidence of canal aberrations begins to increase after prepared by finishing files of ProTaper.The presence of unprepared area suggests that it is essential to rinse canal abundantly during complicated canal preparation and canal antisepsis after preparation.

Disinfection of Contaminated Canals by Different Laser Wavelengths, while Performing Root Canal Therapy

PubMed Central

Asnaashari, Mohammad; Safavi, Nassimeh

2013-01-01

Removal of smear layer and disinfection of canals are important objectives of teeth root canal cleaning. In order to achieve this purpose, rinsing substances, intra canal drugs as well as ultrasound are used. Today, use of laser to remove smear layer and to disinfect root canals has increasingly attracted the attentions. Till now different lasers such as CO2, Nd:YAG, Er:YAG, Er,Cr:YSGG have been used for debris and smear removal from the canals. Numerous studies have shown that Er:YAG is the most appropriate laser for intra canal debris and smear removal. In addition different laser wavelengths have been used directly or as an adjunctive to disinfect canals. Laser light can penetrate areas of canals where irrigating and disinfecting solutions cannot reach, like secondary canals and deep dentinal tubules and also can eliminate microorganisms. Different studies have confirmed the penetration of Nd:YAG laser in deep dentin and reduction of microorganisms penetration. But studies on comparison of antibacterial effects of Nd:YAG laser with sodium hypochlorite showed effectiveness of both, with a better effect for sodium hypochlorite. Studies performed in relation with anti-microbial effects of Diode laser with various parameters show that this laser can be effective in reducing intra canal bacterial count and penetration in the depth of 500 microns in dentin. In studies performed on Diode laser in combination with canal irrigating solutions such as sodium hypochlorite and oxygenated water better results were obtained. Although studies on disinfection by the Erbium laser family show that use of this laser alone can be effective in disinfecting canals, studies evaluating the disinfecting effects of this laser and different concentrations of sodium hypochlorite show that the latter alone is more effective in disinfecting canals. And better results were obtained when Erbium laser was used in combination with sodium hypochlorite irrigating solution in canals. Results of the

Evaluation of a commercial flatbed document scanner and radiographic film scanner for radiochromic EBT film dosimetry

PubMed Central

Parker, Brent C.; Neck, Daniel W.; Henkelmann, Greg; Rosen, Isaac I.

2010-01-01

The purpose of this study was to quantify the performance and assess the utility of two different types of scanners for radiochromic EBT film dosimetry: a commercial flatbed document scanner and a widely used radiographic film scanner. We evaluated the Epson Perfection V700 Photo flatbed scanner and the Vidar VXR Dosimetry Pro Advantage scanner as measurement devices for radiochromic EBT film. Measurements were made of scan orientation effects, response uniformity, and scanner noise. Scanners were tested using films irradiated with eight separate 3×3 cm2 fields to doses ranging from 0.115–5.119 Gy. ImageJ and RIT software was used for analyzing the Epson and Vidar scans, respectively. For repeated scans of a single film, the measurements in each dose region were reproducible to within ±0.3% standard deviation (SD) with both scanners. Film‐to‐film variations for corresponding doses were measured to be within ±0.4% SD for both Epson scanner and Vidar scanners. Overall, the Epson scanner showed a 10% smaller range of pixel value compared to the Vidar scanner. Scanner noise was small: ±0.3% SD for the Epson and ±0.2% for the Vidar. Overall measurement uniformity for blank film in both systems was better than ±0.2%, provided that the leading and trailing 2 cm film edges were neglected in the Vidar system. In this region artifacts are attributed to the film rollers. Neither system demonstrated a clear measurement advantage. The Epson scanner is a relatively inexpensive method for analyzing radiochromic film, but there is a lack of commercially available software. For a clinic already using a Vidar scanner, applying it to radiochromic film is attractive because commercial software is available. However, care must be taken to avoid using the leading and trailing film edges. PACS number: 87.55.Qr

Your baby in the birth canal

MedlinePlus

... lie; Fetal attitude; Fetal descent; Fetal station; Cardinal movements; Labor-birth canal; Delivery-birth canal ... are used to describe your baby's position and movement through the birth canal. FETAL STATION Fetal station ...

Scanner imaging systems, aircraft

NASA Technical Reports Server (NTRS)

Ungar, S. G.

1982-01-01

The causes and effects of distortion in aircraft scanner data are reviewed and an approach to reduce distortions by modelling the effect of aircraft motion on the scanner scene is discussed. With the advent of advanced satellite borne scanner systems, the geometric and radiometric correction of aircraft scanner data has become increasingly important. Corrections are needed to reliably simulate observations obtained by such systems for purposes of evaluation. It is found that if sufficient navigational information is available, aircraft scanner coordinates may be related very precisely to planimetric ground coordinates. However, the potential for a multivalue remapping transformation (i.e., scan lines crossing each other), adds an inherent uncertainty, to any radiometric resampling scheme, which is dependent on the precise geometry of the scan and ground pattern.

In vivo efficacy of three different endodontic irrigation systems for irrigant delivery to working length of mesial canals of mandibular molars.

PubMed

Munoz, Hugo Roberto; Camacho-Cuadra, Karla

2012-04-01

Many in vitro studies have debated over the ability of different irrigant delivery and/or agitation systems to reach the apical third of curved root canals; however, little is known about irrigant penetration in vivo. Therefore, the purpose of this study was to compare the efficacy of the conventional endodontic irrigation needle, passive ultrasonic irrigation (PUI), and a negative pressure system for irrigant delivery to working length (WL) of mesial canals of mandibular molars. Thirty mesial canals of 30 vital mandibular first or second molars were randomly assigned into 3 groups (n = 10): (1) Monoject syringe with 27-gauge needle; (2) PUI with IrriSafe tip; and (3) EndoVac system. All canals were treated following the same preparation protocol to size 35/0.04 by using 5.25% NaOCl as irrigant during preparation procedure. Before obturation, canals were irrigated with 1 mL of a radiopaque solution by using the assigned irrigation system, and a digital radiograph was taken by using a parallel technique. With the aid of image editing software the distance between WL and maximum irrigant penetration was measured. Mean distances for Monoject, PUI, and EndoVac groups were 1.51 mm, 0.21 mm, and 0.42 mm, respectively. Analysis of variance test showed statistically significant differences between groups (P < .001). Tukey honestly significant difference test showed statistically significant differences between the Monoject group and the other 2 groups (P < .001) but no significant differences between PUI and EndoVac groups (P = .06). PUI and EndoVac are more effective than the conventional endodontic needle in delivering irrigant to WL of root canals. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Forensics for flatbed scanners

NASA Astrophysics Data System (ADS)

Gloe, Thomas; Franz, Elke; Winkler, Antje

2007-02-01

Within this article, we investigate possibilities for identifying the origin of images acquired with flatbed scanners. A current method for the identification of digital cameras takes advantage of image sensor noise, strictly speaking, the spatial noise. Since flatbed scanners and digital cameras use similar technologies, the utilization of image sensor noise for identifying the origin of scanned images seems to be possible. As characterization of flatbed scanner noise, we considered array reference patterns and sensor line reference patterns. However, there are particularities of flatbed scanners which we expect to influence the identification. This was confirmed by extensive tests: Identification was possible to a certain degree, but less reliable than digital camera identification. In additional tests, we simulated the influence of flatfielding and down scaling as examples for such particularities of flatbed scanners on digital camera identification. One can conclude from the results achieved so far that identifying flatbed scanners is possible. However, since the analyzed methods are not able to determine the image origin in all cases, further investigations are necessary.

One-Sided Measurement Approach on Ultrasonic Beam Path Analysis in CFRP Composite Laminates

NASA Astrophysics Data System (ADS)

Im, K. H.; Hsu, D. K.; Kim, H. J.; Song, S. J.; Dayal, V.; Barnard, D.; Park, J. W.; Lee, K. S.; Yang, Y. J.; Yang, I. Y.

2008-02-01

Composite materials are attractive for a wide range of applications because of high performance engineering structures. In particular, the importance of carbon-fiber reinforced plastics (CFRP) has been generally recognized in both space and civil aircraft industries; so, CFRP composite laminates are widely used. It is very important to detect defects in composite laminates because they cause the mechanical properties (stiffness, strength) of the laminate to be reduced. As well known for ultrasonic technique for evaluating the defect of CFRP composite laminates, a pitch-catch technique was found to be more practical than normal incidence backwall echo of longitudinal wave to arbitrary flaws in the composite, including fiber orientation, low level porosity, ply waviness, and cracks. The measurement depth using Rayleigh probes can be increased by increasing the separation distance of the transmitting and receiving probes. Also, with the aid of the automatic scanner, the one-sided pitch-catch probe was used to produce C-scan images for mapping out the images with beam profiles. Especially pitch-catch beam path was nondestructively characterized for the specimens when measuring a peak-to-peak amplitude and time-of-flight in order to build the beam profile modeling in the unidirectional CFRP composite laminates. Also, the pitch-catch simulation was performed to predict the beam profile trend of wave propagation in the unidirectional CF/Epoxy composite laminates. Therefore, it is found that the experimentally Rayleigh wave variation of pitch-catch ultrasonic signal was consistent with simulated results and one-side ultrasonic measurement might be very useful to detect the defects in CFRP composites.

A novel methodology providing insights into removal of biofilm-mimicking hydrogel from lateral morphological features of the root canal during irrigation procedures.

PubMed

Macedo, R G; Robinson, J P; Verhaagen, B; Walmsley, A D; Versluis, M; Cooper, P R; van der Sluis, L W M

2014-11-01

To introduce and characterize a reproducible hydrogel as a suitable biofilm mimic in endodontic research. To monitor and visualize the removal of hydrogel from a simulated lateral canal and isthmus for the following: I) Ultrasonic-Activated Irrigation (UAI) with water, ii) UAI with NaOCl and iii) NaOCl without UAI. A rheometer was used to characterize the viscoelastic properties and cohesive strength of the hydrogel for suitability as a biofilm mimic. The removal rate of the hydrogel from a simulated lateral canal or isthmus was measured by high-speed imaging operating at frame rates from 50 to 30,000 fps. The hydrogel demonstrated viscoelastic behaviour with mechanical properties comparable to real biofilms. UAI enhanced the cleaning effect of NaOCl in isthmi (P < 0.001) and both NaOCl and water in lateral canals (P < 0.001). A greater depth of cleaning was achieved from an isthmus (P = 0.009) than from a lateral canal with UAI and also at a faster rate for the first 20 s. NaOCl without UAI resulted in a greater depth of hydrogel removal from a lateral canal than an isthmus (P < 0.001). The effect of UAI was reduced when stable bubbles were formed and trapped in the lateral canal. Different removal characteristics were observed in the isthmus and the lateral canal, with initial highly unstable behaviour followed by slower viscous removal inside the isthmus. The biofilm-mimicking hydrogel is reproducible, homogenous and can be easily applied and modified. Visualization of its removal from lateral canal anatomy provides insights into the cleaning mechanisms of UAI for a biofilm-like material. Initial results showed that UAI improves hydrogel removal from the accessory canal anatomy, but the creation of stable bubbles on the hydrogel-liquid interface may reduce the cleaning rate. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Efficacy of different irrigation and activation systems on the penetration of sodium hypochlorite into simulated lateral canals and up to working length: an in vitro study.

PubMed

de Gregorio, Cesar; Estevez, Roberto; Cisneros, Rafael; Paranjpe, Avina; Cohenca, Nestor

2010-07-01

The removal of vital and necrotic pulp tissue, microorganisms, and their toxins is essential for endodontic success. However, the complex anatomy of the root canal system has limited our ability to debride it completely. Hence the purpose of this study was to evaluate the effect of currently used irrigation and activation systems on the penetration of sodium hypochlorite into simulated lateral canals and to working length in a closed system. One hundred single-rooted teeth were used in this study. A total of 600 simulated lateral canals were created, 6 in each tooth, with 2 lateral canals at 2, 4.5, and 6 mm of working length. To resemble the clinical situation, a closed system was created by coating each root with soft modeling wax. Roots were then randomly assigned to 4 experimental groups: group 1 (n = 20), Endoactivator (sonic activation); group 2 (n = 20), passive ultrasonic (PUI) activation; group 3 (n = 20), F file; group 4 (n = 20), apical negative pressure (ANP) irrigation; and control group 5 (n = 20), positive pressure irrigation. The samples were evaluated by direct observation of the images recorded under the dental operating microscope. The results demonstrated that the ANP irrigation group was superior at reaching working length, and PUI was the most effective at lateral canal penetration. The ANP irrigation system demonstrated limited activation of the irrigant into lateral canals but reached the working length significantly more than the other groups tested. In contrast, PUI group demonstrated significantly more penetration of irrigant into lateral canals but not up to the working length. Copyright 2010 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Value added cleaning and disinfection of the root canal: laser-activated irrigation and laser-induced photoporation

NASA Astrophysics Data System (ADS)

De Moor, Roeland J. G.; Meire, Maarten A.

2016-03-01

Among present-day marketed systems ultrasonic activation appears to be the best way to activate and potentiate endodontic irrigants. An alternative for ultrasonic activation of irrigants is laser activated irrigation (LAI) or photoninitiated acoustic streaming. Based on present-day research it appears that LAI (especially with Erbium lasers) can be more efficient for debris removal out of root canals and interaction with the endodontic biofilms thanks to the induction of specific cavitation phenomena and acoustic streaming. Other wavelengths are now explored to be used for LAI. Another way to interact with biofilms is to rely on laser-induced photoporation in combination with gold nanoparticles ( AuNPs). The latter is an alternative physical method for delivering macromolecules in cells. Nanosized membrane pores can be created upon pulsed laser illumination. Depending on the laser energy, pores are created through either direct heating of the AuNPs or by vapour nanobubbles that can emerge around the AuNPs.

Detection of Mesiobuccal Canal in Maxillary Molars and Distolingual Canal in Mandibular Molars by Dental CT: A Retrospective Study of 100 Cases

PubMed Central

Rathi, Sushma; Patil, Jayaprakash; Jaju, Prashant P.

2010-01-01

Objective. To detect presence of MB2 canal in maxillary molars and distolingual canal in mandibular molars by Dental CT. Material and Methods. A retrospective study of 100 Dental CTs was done. Axial and paraxial images obtained were used to assess the presence of MB2 canal in maxillary molars and distolingual canal in mandibular molars. Results. The youngest patient was of 11 years while the eldest patient was of 77 years. Males were 58 in number and females were 42 in number. MB2 canals were present in 57 patients and distolingual canal was present in 18 patients. Maximum MB2 canals were present in age group between 51 and 60 years, while distolingual canals were present in age group of 21–30 years. Conclusion. Dental CT allows adequate visualization of variation in root canal morphology and can be important diagnostic tool for successful endodontic therapy. PMID:20613946

Morphometric analysis of root canal cleaning after rotary instrumentation with or without laser irradiation

NASA Astrophysics Data System (ADS)

Marchesan, Melissa A.; Geurisoli, Danilo M. Z.; Brugnera, Aldo, Jr.; Barbin, Eduardo L.; Pecora, Jesus D.

2002-06-01

The present study examined root canal cleaning, using the optic microscope, after rotary instrumentation with ProFile.04 with or without laser application with different output energies. Cleaning and shaping can be accomplished manually, with ultra-sonic and sub-sonic devices, with rotary instruments and recently, increasing development in laser radiation has shown promising results for disinfection and smear layer removal. In this study, 30 palatal maxillary molar roots were examined using an optic microscope after rotary instrumentation with ProFile .04 with or without Er:YAG laser application (KaVo KeyLaser II, Germany) with different output energies (2940 nm, 15 Hz, 300 pulses, 500 milli-sec duration, 42 J, 140 mJ showed on the display- input, 61 mJ at fiberoptic tip-output and 140 mJ showed on the display-input and 51 mJ at fiberoptic tip-output). Statistical analysis showed no statistical differences between the tested treatments (ANOVA, p>0.05). ANOVA also showed a statistically significant difference (p<0.01) between the root canal thirds, indicating that the middle third had less debris than the apical third. We conclude that: 1) none of the tested treatments led to totally cleaned root canals; 2) all treatments removed debris similarly, 3) the middle third had less debris than the apical third; 4) variation in output energy did not increase cleaning.

Cleaning lateral morphological features of the root canal: the role of streaming and cavitation.

PubMed

Robinson, J P; Macedo, R G; Verhaagen, B; Versluis, M; Cooper, P R; van der Sluis, L W M; Walmsley, A D

2018-01-01

To investigate the effects of ultrasonic activation file type, lateral canal location and irrigant on the removal of a biofilm-mimicking hydrogel from a fabricated lateral canal. Additionally, the amount of cavitation and streaming was quantified for these parameters. An intracanal sonochemical dosimetry method was used to quantify the cavitation generated by an IrriSafe 25 mm length, size 25 file inside a root canal model filled with filtered degassed/saturated water or three different concentrations of NaOCl. Removal of a hydrogel, demonstrated previously to be an appropriate biofilm mimic, was recorded to measure the lateral canal cleaning rate from two different instruments (IrriSafe 25 mm length, size 25 and K 21 mm length, size 15) activated with a P5 Suprasson (Satelec) at power P8.5 in degassed/saturated water or NaOCl. Removal rates were compared for significant differences using nonparametric Kruskal-Wallis and/or Mann-Whitney U-tests. Streaming was measured using high-speed particle imaging velocimetry at 250 kfps, analysing both the oscillatory and steady flow inside the lateral canals. There was no significant difference in amount of cavitation between tap water and oversaturated water (P = 0.538), although more cavitation was observed than in degassed water. The highest cavitation signal was generated with NaOCl solutions (1.0%, 4.5%, 9.0%) (P < 0.007) and increased with concentration (P < 0.014). The IrriSafe file outperformed significantly the K-file in removing hydrogel (P < 0.05). Up to 64% of the total hydrogel volume was removed after 20 s. The IrriSafe file typically outperformed the K-file in generating streaming. The oscillatory velocities were higher inside the lateral canal 3 mm compared to 6 mm from WL and were higher for NaOCl than for saturated water, which in turn was higher than for degassed water. Measurements of cavitation and acoustic streaming have provided insight into their contribution to cleaning. Significant

Canal Aberration Assessment in Simulated Root Canals: a Comparative Study

PubMed Central

Jakupovic, Selma; Konjhodzic, Alma; Brankovic, Lajla Hasic; Korac, Samra; Tahmiscija, Irmina; Dzankovic, Aida; Glamoc, Alma Gavranovic

2017-01-01

Aim: The aim of this study was to compare time of preparation and canal aberrations in a simulated root canals after using three different rotary systems: Endostar E5, Endostar E3 and T One File Gold. Materials and Methods: A total of 90 endodontic training blocks were used in this study and divided into three groups consisting of 30 each (n = 30). Blocks processing was performed by thirty dentists without any prior experience in rotary instrumentation techniques. In the first group blocks were prepared using Endostar E5, in second one with Endostar E3 and in third one with T One File Gold system. The preparation time was measured. The postoperative image of each block was taken by stereomicroscope and canal aberrations (ledge and instrument fracture) was recorded. Statistical analysis was done by SPSS software. Results: Instrumentation with T One File Gold system is significantly faster compared to instrumentation with Endostar E5 and Endostar E3 systems (p <0.05). There are no statistically significant differences in the type and number of procedural errors between Endostar E5, Endostar E3 and T One File Gold systems when the operators have no previous experience in rotary instrumentation techniques. Conclusion: Under the conditions of this study, the incidence of examined canal aberrations were similar for all tested systems. The preparation time was significantly shorter with single file system. PMID:28974834

Analysis of temperature rise and the use of coolants in the dissipation of ultrasonic heat buildup during post removal.

PubMed

Davis, Stephen; Gluskin, Alan H; Livingood, Philip M; Chambers, David W

2010-11-01

This study was designed to calculate probabilities for tissue injury and to measure effectiveness of various coolant strategies in countering heat buildup produced by dry ultrasonic vibration during post removal. A simulated biological model was used to evaluate the cooling efficacy of a common refrigerant spray, water spray, and air spray in the recovery of post temperatures deep within the root canal space. The data set consisted of cervical and apical measures of temperature increase at 1-second intervals from baseline during continuous ultrasonic instrumentation until a 10 °C increase in temperature at the cervical site was registered, wherein instrumentation ceased, and the teeth were allowed to cool under ambient conditions or with the assistance of 4 coolant methods. Data were analyzed with analysis of variance by using the independent variables of time of ultrasonic application (10, 15, 20 seconds) and cooling method. In addition to the customary means, standard deviations, and analysis of variance tests, analyses were conducted to determine probabilities that procedures would reach or exceed the 10 °C threshold. Both instrumentation time and cooling agent effects were significant at P <.0001. Under the conditions of this study, it was shown that injurious heat transfer occurs in less than 1 minute during dry ultrasonic instrumentation of metallic posts. Cycles of short instrumentation times with active coolants were effective in reducing the probability of tissue damage when teeth were instrumented dry. With as little as 20 seconds of continuous dry ultrasonic instrumentation, the consequences of thermal buildup to an individual tooth might contribute to an injurious clinical outcome. Copyright © 2010 American Association of Endodontists. All rights reserved.

Applications of Optical Scanners in an Academic Center.

ERIC Educational Resources Information Center

Molinari, Carol; Tannenbaum, Robert S.

1995-01-01

Describes optical scanners, including how the technology works; applications in data management and research; development of instructional materials; and providing community services. Discussion includes the three basic types of optical scanners: optical character recognition (OCR), optical mark readers (OMR), and graphic scanners. A sidebar…

ASTER Suez Canal

NASA Image and Video Library

2000-10-06

One of the most important waterways in the world, the Suez Canal runs north to south across the Isthmus of Suez in northeastern Egypt. This image of the canal covers an area 36 kilometers (22 miles) wide and 60 kilometers (47 miles) long in three bands of the reflected visible and infrared wavelength region. It shows the northern part of the canal, with the Mediterranean Sea just visible in the upper right corner. The Suez Canal connects the Mediterranean Sea with the Gulf of Suez, an arm of the Red Sea. The artificial canal provides an important shortcut for ships operating between both European and American ports and ports located in southern Asia, eastern Africa, and Oceania. With a length of about 195 kilometers (121 miles) and a minimum channel width of 60 meters (197 feet), the Suez Canal is able to accommodate ships as large as 150,000 tons fully loaded. Because no locks interrupt traffic on this sea level waterway, the transit time only averages about 15 hours. ASTER acquired this scene on May 19, 2000. http://photojournal.jpl.nasa.gov/catalog/PIA02661

An evaluation of .06 tapered gutta-percha cones for filling of .06 taper prepared curved root canals.

PubMed

Gordon, M P J; Love, R M; Chandler, N P

2005-02-01

To compare the area occupied by gutta-percha, sealer, or void in standardized .06 tapered prepared simulated curved canals and in mesio-buccal canals of extracted maxillary first molars filled with a single .06 gutta-percha point and sealer or lateral condensation of multiple .02 gutta-percha points and sealer. Simulated canals in resin blocks with either a 30 degrees curve and radius of 10.5 mm (n = 20) or a 58 degrees curve and 4.7 mm radius (n = 20) and curved mesio-buccal canals of extracted maxillary first molars (n = 20) were prepared using .06 ProFiles in a variable tip crown-down sequence to an apical size 35 at 0.5 mm from the canal terminus or apical foramen. Ten 30 degrees and 58 degrees curved resin canals and 10 canals in the extracted teeth group were obturated with .02 taper gutta-percha cones and AH 26 sealer using lateral condensation. The time required to obturate was recorded. The remaining canals were obturated with a single .06 taper gutta-percha cone and AH 26 sealer. Excess gutta-percha was removed from the specimens using heat and the warm mass vertically condensed. Horizontal sections were cut at 0.5, 1.5, 2.5, 4.5, 7.5 and 11.5 mm from the canal terminus or apical foramen. Colour photographs were taken using an Olympus 35 mm camera attached to a stereomicroscope set at x40 magnification, and then digitized using a flatbed scanner. The cross-sectional area of the canal contents was analysed using Adobe PhotoShop. The percentage of gutta-percha, sealer or voids to the total root canal area were derived and data analysed using unpaired Student's t-test and the Mann-Whitney U-test. In the 30 degrees curved canals the levels had between 94 and 100% of the area filled with gutta-percha with no significant difference (P > 0.05) between the lateral condensation and single cone techniques. In the 58 degrees curved canals the levels had 92-99% of the area filled with gutta-percha, with the single cone technique having significantly (P < 0.05) more

Complete-arch accuracy of intraoral scanners.

PubMed

Treesh, Joshua C; Liacouras, Peter C; Taft, Robert M; Brooks, Daniel I; Raiciulescu, Sorana; Ellert, Daniel O; Grant, Gerald T; Ye, Ling

2018-04-30

Intraoral scanners have shown varied results in complete-arch applications. The purpose of this in vitro study was to evaluate the complete-arch accuracy of 4 intraoral scanners based on trueness and precision measurements compared with a known reference (trueness) and with each other (precision). Four intraoral scanners were evaluated: CEREC Bluecam, CEREC Omnicam, TRIOS Color, and Carestream CS 3500. A complete-arch reference cast was created and printed using a 3-dimensional dental cast printer with photopolymer resin. The reference cast was digitized using a laboratory-based white light 3-dimensional scanner. The printed reference cast was scanned 10 times with each intraoral scanner. The digital standard tessellation language (STL) files from each scanner were then registered to the reference file and compared with differences in trueness and precision using a 3-dimensional modeling software. Additionally, scanning time was recorded for each scan performed. The Wilcoxon signed rank, Kruskal-Wallis, and Dunn tests were used to detect differences for trueness, precision, and scanning time (α=.05). Carestream CS 3500 had the lowest overall trueness and precision compared with Bluecam and TRIOS Color. The fourth scanner, Omnicam, had intermediate trueness and precision. All of the scanners tended to underestimate the size of the reference file, with exception of the Carestream CS 3500, which was more variable. Based on visual inspection of the color rendering of signed differences, the greatest amount of error tended to be in the posterior aspects of the arch, with local errors exceeding 100 μm for all scans. The single capture scanner Carestream CS 3500 had the overall longest scan times and was significantly slower than the continuous capture scanners TRIOS Color and Omnicam. Significant differences in both trueness and precision were found among the scanners. Scan times of the continuous capture scanners were faster than the single capture scanners

An operational multispectral scanner for bathymetric surveys - The ABS NORDA scanner

NASA Technical Reports Server (NTRS)

Haimbach, Stephen P.; Joy, Richard T.; Hickman, G. Daniel

1987-01-01

The Naval Ocean Research and Development Activity (NORDA) is developing the Airborne Bathymetric Survey (ABS) system, which will take shallow water depth soundings from a Navy P-3 aircraft. The system combines active and passive sensors to obtain optical measurements of water depth. The ABS NORDA Scanner is the systems passive multispectral scanner whose design goal is to provide 100 percent coverage of the seafloor, to depths of 20 m in average coastal waters. The ABS NORDA Scanner hardware and operational environment is discussed in detail. The optical model providing the basis for depth extraction is reviewed and the proposed data processing routine discussed.

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

PubMed

Brkanić, Tatjana; Ivana, Stojsin; Vukoje, Karolina; Zivković, Slavoljub

2010-01-01

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. 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. 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. 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 GTand ProTaperfiles 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. 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.

A Simple X-Y Scanner.

ERIC Educational Resources Information Center

Halse, M. R.; Hudson, W. J.

1986-01-01

Describes an X-Y scanner used to create acoustic holograms. Scanner is computer controlled and can be adapted to digitize pictures. Scanner geometry is discussed. An appendix gives equipment details. The control program in ATOM BASIC and 6502 machine code is available from the authors. (JM)

Ultrasonic Interferometers Revisited

ERIC Educational Resources Information Center

Greenslade, Thomas B., Jr.

2007-01-01

I have been tinkering with ultrasonic transducers once more. In earlier notes I reported on optics-like experiments performed with ultrasonics, described a number of ultrasonic interferometers, and showed how ultrasonic transducers can be used for Fourier analysis. This time I became interested in trying the technique of using two detectors in…

Canal Transportation and Centering Ability of ProTaper and SafeSider in Preparation of Curved Root Canals: A CBCT Evaluation

PubMed Central

Delgoshayi, Negar; Abbasi, Mansoure; Bakhtiar, Hengameh; Sakhdari, Shirin; Ghannad, Setareh; Ellini, Mohammad Reza

2018-01-01

Introduction: Maintaining the original central canal path is an important parameter in efficient root canal preparation. Instruments causing minimal changes in original canal path are preferred for this purpose. This study sought to compare canal transportation and centering ability of ProTaper and SafeSider instruments in curved mesiobuccal root canals of mandibular first molars using cone beam computed tomography (CBCT). Methods and Materials : In this experimental study, 30 mesiobuccal root canals of extracted human mandibular first molars with 20° to 40° curvature were randomly divided into two groups (n=15). After mounting in putty, preoperative CBCT scans were obtained of teeth. Root canals in group A were shaped using S1, S2, F1 and F2 of ProTaper system. Root canals in group B were instrumented to size 25 using SafeSider system according to the manufacturers’ instructions. Postoperative CBCT scans were then obtained. The distance between the external root surface and internal canal wall was measured at the mesial and distal at 1, 3 and 7 mm from the apex. The values measured on primary and secondary CBCT scans were compared to assess possible changes in original central canal path and canal transportation. Data were compared using the t-test and repeated measure ANOVA. Results: ProTaper and SafeSider were significantly different in terms of canal transportation and centering ability, and ProTaper was significantly superior to SafeSider in this respect (P<0.001). Conclusion: ProTaper (in contrast to SafeSider) is well capable of maintaining the original central canal path with the least amount of transportation. PMID:29707022

Human tooth and root canal morphology reconstruction using magnetic resonance imaging.

PubMed

Drăgan, Oana Carmen; Fărcăşanu, Alexandru Ştefan; Câmpian, Radu Septimiu; Turcu, Romulus Valeriu Flaviu

2016-01-01

Visualization of the internal and external root canal morphology is very important for a successful endodontic treatment; however, it seems to be difficult considering the small size of the tooth and the complexity of the root canal system. Film-based or digital conventional radiographic techniques as well as cone beam computed tomography provide limited information on the dental pulp anatomy or have harmful effects. A new non-invasive diagnosis tool is magnetic resonance imaging, due to its ability of imaging both hard and soft tissues. The aim of this study was to demonstrate magnetic resonance imaging to be a useful tool for imaging the anatomic conditions of the external and internal root canal morphology for endodontic purposes. The endodontic system of one freshly extracted wisdom tooth, chosen for its well-known anatomical variations, was mechanically shaped using a hybrid technique. After its preparation, the tooth was immersed into a recipient with saline solution and magnetic resonance imaged immediately. A Bruker Biospec magnetic resonance imaging scanner operated at 7.04 Tesla and based on Avance III radio frequency technology was used. InVesalius software was employed for the 3D reconstruction of the tooth scanned volume. The current ex-vivo experiment shows the accurate 3D volume rendered reconstruction of the internal and external morphology of a human extracted and endodontically treated tooth using a dataset of images acquired by magnetic resonance imaging. The external lingual and vestibular views of the tooth as well as the occlusal view of the pulp chamber, the access cavity, the distal canal opening on the pulp chamber floor, the coronal third of the root canals, the degree of root separation and the apical fusion of the two mesial roots, details of the apical region, root canal curvatures, furcal region and interradicular root grooves could be clearly bordered. Magnetic resonance imaging offers 3D image datasets with more information than the

Effect of ultrasound streaming on the disinfection of flattened root canals prepared by rotary and reciprocating systems

PubMed Central

de Vasconcelos, Layla Reginna Silva Munhoz; Midena, Raquel Zanin; Minotti, Paloma Gagliardi; Pereira, Thais Cristina; Duarte, Marco Antonio Hungaro; de Andrade, Flaviana Bombarda

2017-01-01

Abstract New technical and scientific developments have been advocated to promote the success of the endodontic treatment. In addition to rotary and reciprocating systems, irrigating solution agitation has been suggested and passive ultrasonic irrigation (PUI) is the most used. Objective: To evaluate, in vitro, the effect of ultrasound streaming (US) in the disinfection of flattened root canal systems prepared by the ProTaper, BioRaCe and Reciproc systems, utilizing the microbiological culture. Methodology: Extracted human mandibular incisors (n=84) were used. Suspensions of Enterococcus faecalis (ATCC 29212) were standardized and inserted along with the teeth immersed in brain-heart infusion (BHI) broth. The contamination was made following a protocol during 5 days. The teeth were randomly divided into six groups: G1, ProTaper Universal; G2, ProTaper Universal with US; G3, BioRaCe; G4, BioRaCe with US; G5, Reciproc; and G6, Reciproc with US. Irrigation was performed with saline solution. After biomechanical preparation, microbiological samples were performed with sterilized paper points, which were diluted and spread on BHI agar; after 48 h, the colony forming units (CFU/mL) were counted for each sample. Results: Groups using ultrasonic agitation presented a greater antibacterial effect than the other ones, even using saline solution as irrigant. The ProTaper Universal system showed the best antibacterial activity of the tested systems (median of 0 CFU/mL with and without surfactant or ultrasonic activation [PUI]). Even with PUI, Reciproc (median of 2.5 CFU/mL with PUI and 5 without it) could not reduce as many colonies as ProTaper Universal without US. The BioRaCe system had greater bacterial reduction when using US (median of 0 CFU/mL with PUI and 30 without it). Conclusions: US promoted greater reduction in the number of bacteria in the flattened root canals prepared with nickel-titanium mechanized systems. Regarding the instruments used, the ProTaper Universal

Effect of ultrasound streaming on the disinfection of flattened root canals prepared by rotary and reciprocating systems.

PubMed

Vasconcelos, Layla Reginna Silva Munhoz de; Midena, Raquel Zanin; Minotti, Paloma Gagliardi; Pereira, Thais Cristina; Duarte, Marco Antonio Hungaro; Andrade, Flaviana Bombarda de

2017-01-01

New technical and scientific developments have been advocated to promote the success of the endodontic treatment. In addition to rotary and reciprocating systems, irrigating solution agitation has been suggested and passive ultrasonic irrigation (PUI) is the most used. To evaluate, in vitro, the effect of ultrasound streaming (US) in the disinfection of flattened root canal systems prepared by the ProTaper, BioRaCe and Reciproc systems, utilizing the microbiological culture. Extracted human mandibular incisors (n=84) were used. Suspensions of Enterococcus faecalis (ATCC 29212) were standardized and inserted along with the teeth immersed in brain-heart infusion (BHI) broth. The contamination was made following a protocol during 5 days. The teeth were randomly divided into six groups: G1, ProTaper Universal; G2, ProTaper Universal with US; G3, BioRaCe; G4, BioRaCe with US; G5, Reciproc; and G6, Reciproc with US. Irrigation was performed with saline solution. After biomechanical preparation, microbiological samples were performed with sterilized paper points, which were diluted and spread on BHI agar; after 48 h, the colony forming units (CFU/mL) were counted for each sample. Groups using ultrasonic agitation presented a greater antibacterial effect than the other ones, even using saline solution as irrigant. The ProTaper Universal system showed the best antibacterial activity of the tested systems (median of 0 CFU/mL with and without surfactant or ultrasonic activation [PUI]). Even with PUI, Reciproc (median of 2.5 CFU/mL with PUI and 5 without it) could not reduce as many colonies as ProTaper Universal without US. The BioRaCe system had greater bacterial reduction when using US (median of 0 CFU/mL with PUI and 30 without it). US promoted greater reduction in the number of bacteria in the flattened root canals prepared with nickel-titanium mechanized systems. Regarding the instruments used, the ProTaper Universal system was the most effective in reducing the

Ultrasonic pulser-receiver

DOEpatents

Taylor, Steven C.

2006-09-12

Ultrasonic pulser-receiver circuitry, for use with an ultrasonic transducer, the circuitry comprising a circuit board; ultrasonic pulser circuitry supported by the circuit board and configured to be coupled to an ultrasonic transducer and to cause the ultrasonic transducer to emit an ultrasonic output pulse; receiver circuitry supported by the circuit board, coupled to the pulser circuitry, including protection circuitry configured to protect against the ultrasonic pulse and including amplifier circuitry configured to amplify an echo, received back by the transducer, of the output pulse; and a connector configured to couple the ultrasonic transducer directly to the circuit board, to the pulser circuitry and receiver circuitry, wherein impedance mismatches that would result if the transducer was coupled to the circuit board via a cable can be avoided.

7. O'BRIAN CANAL After its bifurcation with the DenverHudson Canal, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

7. O'BRIAN CANAL After its bifurcation with the Denver-Hudson Canal, flowing into Barr Lake through a protected eagle nesting area - O'Brian Canal, South Platte River Drainage Area Northest of Denver, Brighton, Adams County, CO

Comparison of the Antimicrobial Efficacy of Octenidine Dihydrochloride and Chlorhexidine with and Without Passive Ultrasonic Irrigation - An Invitro Study.

PubMed

Cherian, Bastin; Gehlot, Paras Mull; Manjunath, Mysore Krishnaswamy

2016-06-01

Elimination of microorganisms from infected root canals is a complicated task. Numerous measures have been described to reduce the microbial load in the root canal system, including the use of various instrumentation techniques, irrigation regimens and intracanal medicaments. The drawbacks of few commonly used irrigants include toxic and harmful side effects, microbial resistance to antimicrobial agents and staining. Hence there is a need for alternative agents which are nontoxic, effective and safe. To compare and evaluate antimicrobial effects of 2% Chlorhexidine (CHX) versus 0.1% Octenidine Dihydrochloride (OCT) as root canal irrigant with and without passive ultrasonic irrigation against Enterococcus faecalis (E. faecalis) in vitro and to evaluate the depth of penetration of irrigant solution into the dentinal tubules at the junction of middle and apical third. Forty eight freshly extracted, single rooted human mandibular premolars were decoronated and root specimen standardized to 14mm. Biofilm of E. faecalis (strain ATCC 29212) was grown for seven days and the specimens were divided into four groups (n=12) based on irrigation protocol : Group I- Conventional Syringe Irrigation (CSI) with 2% CHX, Group II- CSI + 0.1% OCT, Group III-Passive Ultrasonic Irrigation (PUI) + 2% CHX and Group IV- PUI+ 0.1% OCT. Dentin shavings were collected at two depths (200μm and 400μm) and total number of colony forming units were determined. The data were statistically analyzed using ANOVA, Scheffes multiple comparison of means and paired t-test (p<0.05). Group III and IV (PUI) showed significant difference compared to Group I and II (CSI) both at 200μm and 400μm (p=0.000). For Group III and Group IV no significant differences were found at 200μm and 400μm (p=1.000 and 0.363 respectively), however significant difference was found between data at 200μm and 400μm for all the four groups (p=0.000). Octenidine (0.1%) was more effective than 2% Chlorhexidine against E

Comparison of the Antimicrobial Efficacy of Octenidine Dihydrochloride and Chlorhexidine with and Without Passive Ultrasonic Irrigation - An Invitro Study

PubMed Central

Cherian, Bastin; Manjunath, Mysore Krishnaswamy

2016-01-01

Introduction Elimination of microorganisms from infected root canals is a complicated task. Numerous measures have been described to reduce the microbial load in the root canal system, including the use of various instrumentation techniques, irrigation regimens and intracanal medicaments. The drawbacks of few commonly used irrigants include toxic and harmful side effects, microbial resistance to antimicrobial agents and staining. Hence there is a need for alternative agents which are nontoxic, effective and safe. Aim To compare and evaluate antimicrobial effects of 2% Chlorhexidine (CHX) versus 0.1% Octenidine Dihydrochloride (OCT) as root canal irrigant with and without passive ultrasonic irrigation against Enterococcus faecalis (E. faecalis) in vitro and to evaluate the depth of penetration of irrigant solution into the dentinal tubules at the junction of middle and apical third. Materials and Methods Forty eight freshly extracted, single rooted human mandibular premolars were decoronated and root specimen standardized to 14mm. Biofilm of E. faecalis (strain ATCC 29212) was grown for seven days and the specimens were divided into four groups (n=12) based on irrigation protocol : Group I- Conventional Syringe Irrigation (CSI) with 2% CHX, Group II- CSI + 0.1% OCT, Group III-Passive Ultrasonic Irrigation (PUI) + 2% CHX and Group IV- PUI+ 0.1% OCT. Dentin shavings were collected at two depths (200μm and 400μm) and total number of colony forming units were determined. The data were statistically analyzed using ANOVA, Scheffes multiple comparison of means and paired t-test (p<0.05). Results Group III and IV (PUI) showed significant difference compared to Group I and II (CSI) both at 200μm and 400μm (p=0.000). For Group III and Group IV no significant differences were found at 200μm and 400μm (p=1.000 and 0.363 respectively), however significant difference was found between data at 200μm and 400μm for all the four groups (p=0.000). Conclusion Octenidine (0

Planer orientation of the bilateral semicircular canals in dizzy patients.

PubMed

Aoki, Sachiko; Takei, Yasuhiko; Suzuki, Kazufumi; Masukawa, Ai; Arai, Yasuko

2012-10-01

Recent development of 3-dimensional analysis of eye movement enabled to detect the eye rotation axis, which is used to determine the responsible semicircular canal(s) in dizzy patients. Therefore, the knowledge of anatomical orientation of bilateral semicircular canals is essential, as all 6 canals influence the eye movements. Employing the new head coordinate system suitable for MR imaging, we calculated the angles of semicircular canal planes of both ears in 11 dizzy patients who had normal caloric response in both ears. The angles between adjacent canal pairs were nearly perpendicular in both ears. The angle between the posterior canal planes and head sagittal plane was 51° and significantly larger the angle between the anterior canal planes and head sagittal plane, which was 35°. The angle between the horizontal canal plane and head sagittal plane was almost orthogonal. Pairs of contralateral synergistic canal planes were not parallel, forming 10° between right and left horizontal canal planes, 17° between right anterior and left posterior canal planes and 19° between the right posterior and left anterior canal planes. Our measurement of the angles of adjacent canal pairs and the angle between each semicircular canal and head sagittal plane coincided with those of previous reports obtained from CT images and skull specimens. However, the angles between contralateral synergistic canal planes were more parallel than those of previous reports. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

A computerized self-compensating system for ultrasonic inspection of airplane structures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Komsky, I.N.; Achenbach, J.D.; Hagemaier, D.

1993-12-31

Application of a self-compensating technique for ultrasonic inspection of airplane structures makes it possible not only to detect cracks in the different layers of joints but also to obtain information on crack sizes. A prototype computerized ultrasonic system, which utilizes the self-compensating method, has been developed for non-destructive inspection of multilayered airplane structures with in-between sealants, such as bolted joints in tail connections. Industrial applications of the system would require deployment of commercially available portable modules for data acquisition and processing. A portable ultrasonic flaw detector EPOCH II manual scanners and HandiScan, and SQL and FCS software modules form themore » PC-based TestPro system have been selected for initial tests. A pair of contact angle-beam transducers were used to generate shear waves in the material. Both hardware and software components of the system have been modified for the application in conjunction with the self-compensating technique. The system has bene tested on two calibration specimens with artificial flaws of different sizes in internal layers of multilayered structures. Ultrasonic signals transmitted through and reflected from the artificial flaws have bene discriminated and characterized using multiple time domain amplitude gates. Then the ratios of the reflection and transmission coefficients, R/T, were calculated for several positions of the transducers. Inspection of measured R/T curves shows it is difficult to visually associate curve shapes with corresponding flaw sizes and orientation. Hence for online classification of these curve shapes, application of an adaptive signal classifier was considered. Several different types and configurations of the classifiers, including a neural network, have been tested. Test results showed that improved performance of the classifier can be achieved by combination of a back-propagation neural network with a signal pre-processing module.« less

Color accuracy and reproducibility in whole slide imaging scanners

PubMed Central

Shrestha, Prarthana; Hulsken, Bas

2014-01-01

Abstract We propose a workflow for color reproduction in whole slide imaging (WSI) scanners, such that the colors in the scanned images match to the actual slide color and the inter-scanner variation is minimum. We describe a new method of preparation and verification of the color phantom slide, consisting of a standard IT8-target transmissive film, which is used in color calibrating and profiling the WSI scanner. We explore several International Color Consortium (ICC) compliant techniques in color calibration/profiling and rendering intents for translating the scanner specific colors to the standard display (sRGB) color space. Based on the quality of the color reproduction in histopathology slides, we propose the matrix-based calibration/profiling and absolute colorimetric rendering approach. The main advantage of the proposed workflow is that it is compliant to the ICC standard, applicable to color management systems in different platforms, and involves no external color measurement devices. We quantify color difference using the CIE-DeltaE2000 metric, where DeltaE values below 1 are considered imperceptible. Our evaluation on 14 phantom slides, manufactured according to the proposed method, shows an average inter-slide color difference below 1 DeltaE. The proposed workflow is implemented and evaluated in 35 WSI scanners developed at Philips, called the Ultra Fast Scanners (UFS). The color accuracy, measured as DeltaE between the scanner reproduced colors and the reference colorimetric values of the phantom patches, is improved on average to 3.5 DeltaE in calibrated scanners from 10 DeltaE in uncalibrated scanners. The average inter-scanner color difference is found to be 1.2 DeltaE. The improvement in color performance upon using the proposed method is apparent with the visual color quality of the tissue scans. PMID:26158041

Root canal volume change and transportation by Vortex Blue, ProTaper Next, and ProTaper Universal in curved root canals

PubMed Central

2018-01-01

Objectives The aim of this study was to compare root canal volume change and canal transportation by Vortex Blue (VB; Dentsply Tulsa Dental Specialties), ProTaper Next (PTN; Dentsply Maillefer), and ProTaper Universal (PTU; Dentsply Maillefer) nickel-titanium rotary files in curved root canals. Materials and Methods Thirty canals with 20°–45° of curvature from extracted human molars were used. Root canal instrumentation was performed with VB, PTN, and PTU files up to #30.06, X3, and F3, respectively. Changes in root canal volume before and after the instrumentation, and the amount and direction of canal transportation at 1, 3, and 5 mm from the root apex were measured by using micro-computed tomography. Data of canal volume change were statistically analyzed using one-way analysis of variance and Tukey test, while data of amount and direction of transportation were analyzed using Kruskal-Wallis and Mann-Whitney U test. Results There were no significant differences among 3 groups in terms of canal volume change (p > 0.05). For the amount of transportation, PTN showed significantly less transportation than PTU at 3 mm level (p = 0.005). VB files showed no significant difference in canal transportation at all 3 levels with either PTN or PTU files. Also, VB files showed unique inward transportation tendency in the apical area. Conclusions Other than PTN produced less amount of transportation than PTU at 3 mm level, all 3 file systems showed similar level of canal volume change and transportation, and VB file system could prepare the curved canals without significant shaping errors. PMID:29487834

2. VIEW SOUTH, GENERAL VIEW SHOWING CANAL, CANAL SPILLWAY ON ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. VIEW SOUTH, GENERAL VIEW SHOWING CANAL, CANAL SPILLWAY ON LEFT, DRAIN GATE GATEHOUSE IN DISTANCE - Norwich Water Power Company, West bank of Shetucket River beginning opposite Second Street & extending .8 mile northward, Greenville section, Norwich, New London County, CT

Prevalence of the middle mesial canal in non surgical root canal treated mandibular first and second molars in a local military population

DTIC Science & Technology

2016-06-13

unless the clinician is careful to identify it. Missing this canal can contribute to a sequelae of persistent disease that may require the retreatment of...likelihood of finding MM canals. This is likely due to the fact that root canal retreatments are done on an older patient at a higher rate in the...canal. However, missing a canal can lead to continued pain and discomfort to the patient and other sequelae that may require nonsurgical retreatment

Endoscopic root canal treatment.

PubMed

Moshonov, Joshua; Michaeli, Eli; Nahlieli, Oded

2009-10-01

To describe an innovative endoscopic technique for root canal treatment. Root canal treatment was performed on 12 patients (15 teeth), using a newly developed endoscope (Sialotechnology), which combines an endoscope, irrigation, and a surgical microinstrument channel. Endoscopic root canal treatment of all 15 teeth was successful with complete resolution of all symptoms (6-month follow-up). The novel endoscope used in this study accurately identified all microstructures and simplified root canal treatment. The endoscope may be considered for use not only for preoperative observation and diagnosis but also for active endodontic treatment.

Ultrasonic pipe assessment

DOEpatents

Thomas, Graham H.; Morrow, Valerie L.; Levie, Harold; Kane, Ronald J.; Brown, Albert E.

2003-12-23

An ultrasonic pipe or other structure assessment system includes an ultrasonic transducer positioned proximate the pipe or other structure. A fluid connection between the ultrasonic transducer and the pipe or other structure is produced. The ultrasonic transducer is moved relative to the pipe or other structure.

Developments in holographic-based scanner designs

NASA Astrophysics Data System (ADS)

Rowe, David M.

1997-07-01

Holographic-based scanning systems have been used for years in the high resolution prepress markets where monochromatic lasers are generally utilized. However, until recently, due to the dispersive properties of holographic optical elements (HOEs), along with the high cost associated with recording 'master' HOEs, holographic scanners have not been able to penetrate major scanning markets such as the laser printer and digital copier markets, low to mid-range imagesetter markets, and the non-contact inspection scanner market. Each of these markets has developed cost effective laser diode based solutions using conventional scanning approaches such as polygon/f-theta lens combinations. In order to penetrate these markets, holographic-based systems must exhibit low cost and immunity to wavelength shifts associated with laser diodes. This paper describes recent developments in the design of holographic scanners in which multiple HOEs, each possessing optical power, are used in conjunction with one curved mirror to passively correct focal plane position errors and spot size changes caused by the wavelength instability of laser diodes. This paper also describes recent advancements in low cost production of high quality HOEs and curved mirrors. Together these developments allow holographic scanners to be economically competitive alternatives to conventional devices in every segment of the laser scanning industry.

Ultrasonic Shear Wave Elasticity Imaging (SWEI) Sequencing and Data Processing Using a Verasonics Research Scanner

PubMed Central

Deng, Yufeng; Rouze, Ned C.; Palmeri, Mark L.; Nightingale, Kathryn R.

2017-01-01

Ultrasound elasticity imaging has been developed over the last decade to estimate tissue stiffness. Shear wave elasticity imaging (SWEI) quantifies tissue stiffness by measuring the speed of propagating shear waves following acoustic radiation force excitation. This work presents the sequencing and data processing protocols of SWEI using a Verasonics system. The selection of the sequence parameters in a Verasonics programming script is discussed in detail. The data processing pipeline to calculate group shear wave speed (SWS), including tissue motion estimation, data filtering, and SWS estimation is demonstrated. In addition, the procedures for calibration of beam position, scanner timing, and transducer face heating are provided to avoid SWS measurement bias and transducer damage. PMID:28092508

Spatial orientation of semicircular canals and afferent sensitivity vectors in pigeons

NASA Technical Reports Server (NTRS)

Dickman, J. D.

1996-01-01

Rotational head motion in vertebrates is detected by the semicircular canal system, whose innervating primary afferent fibers carry information about movement in specific head planes. The semicircular canals have been qualitatively examined over a number of years, and the canal planes have been quantitatively characterized in several animal species. The present study first determined the geometric relationship between individual semicircular canals and between the canals and the stereotactic head planes in pigeons. Stereotactic measurements of multiple points along the circumference of the bony canals were taken, and the measured points fitted with a three-dimensional planar surface. Direction normals to the plane's surface were calculated and used to define angles between semicircular canal pairs. Because of the unusual shape of the anterior semicircular canals in pigeons, two planes, a major and a minor, were fitted to the canal's course. Calculated angle values for all canals indicated that the horizontal and posterior semicircular canals are nearly orthogonal, but the anterior canals have substantial deviations from orthogonality with other canal planes. Next, the responses of the afferent fibers that innervate each of the semicircular canals to 0.5 Hz sinusoidal rotation about an earth-vertical axis were obtained. The head orientation relative to the rotation axis was systematically varied so that directions of maximum sensitivity for each canal afferent could be determined. These sensitivity vectors were then compared with the canal plane direction normals. The afferents that innervated specific semicircular canals formed homogeneous clusters of sensitivity vectors in different head planes. The horizontal and posterior afferents had average sensitivity vectors that were largely co-incident with the innervated canal plane direction normals. Anterior canal afferents, however, appeared to synthesize contributions from the major and minor plane components of the

Compressed Sensing Techniques Applied to Ultrasonic Imaging of Cargo Containers.

PubMed

López, Yuri Álvarez; Lorenzo, José Ángel Martínez

2017-01-15

One of the key issues in the fight against the smuggling of goods has been the development of scanners for cargo inspection. X-ray-based radiographic system scanners are the most developed sensing modality. However, they are costly and use bulky sources that emit hazardous, ionizing radiation. Aiming to improve the probability of threat detection, an ultrasonic-based technique, capable of detecting the footprint of metallic containers or compartments concealed within the metallic structure of the inspected cargo, has been proposed. The system consists of an array of acoustic transceivers that is attached to the metallic structure-under-inspection, creating a guided acoustic Lamb wave. Reflections due to discontinuities are detected in the images, provided by an imaging algorithm. Taking into consideration that the majority of those images are sparse, this contribution analyzes the application of Compressed Sensing (CS) techniques in order to reduce the amount of measurements needed, thus achieving faster scanning, without compromising the detection capabilities of the system. A parametric study of the image quality, as a function of the samples needed in spatial and frequency domains, is presented, as well as the dependence on the sampling pattern. For this purpose, realistic cargo inspection scenarios have been simulated.

Compressed Sensing Techniques Applied to Ultrasonic Imaging of Cargo Containers

PubMed Central

Álvarez López, Yuri; Martínez Lorenzo, José Ángel

2017-01-01

One of the key issues in the fight against the smuggling of goods has been the development of scanners for cargo inspection. X-ray-based radiographic system scanners are the most developed sensing modality. However, they are costly and use bulky sources that emit hazardous, ionizing radiation. Aiming to improve the probability of threat detection, an ultrasonic-based technique, capable of detecting the footprint of metallic containers or compartments concealed within the metallic structure of the inspected cargo, has been proposed. The system consists of an array of acoustic transceivers that is attached to the metallic structure-under-inspection, creating a guided acoustic Lamb wave. Reflections due to discontinuities are detected in the images, provided by an imaging algorithm. Taking into consideration that the majority of those images are sparse, this contribution analyzes the application of Compressed Sensing (CS) techniques in order to reduce the amount of measurements needed, thus achieving faster scanning, without compromising the detection capabilities of the system. A parametric study of the image quality, as a function of the samples needed in spatial and frequency domains, is presented, as well as the dependence on the sampling pattern. For this purpose, realistic cargo inspection scenarios have been simulated. PMID:28098841

Scanners for analytic print measurement: the devil in the details

NASA Astrophysics Data System (ADS)

Zeise, Eric K.; Williams, Don; Burns, Peter D.; Kress, William C.

2007-01-01

Inexpensive and easy-to-use linear and area-array scanners have frequently substituted as colorimeters and densitometers for low-frequency (i.e., large area) hard copy image measurement. Increasingly, scanners are also being used for high spatial frequency, image microstructure measurements, which were previously reserved for high performance microdensitometers. In this paper we address characteristics of flatbed reflection scanners in the evaluation of print uniformity, geometric distortion, geometric repeatability and the influence of scanner MTF and noise on analytic measurements. Suggestions are made for the specification and evaluation of scanners to be used in print image quality standards that are being developed.

Middle mesial canals in mandibular molars: incidence and related factors.

PubMed

Nosrat, Ali; Deschenes, Raney J; Tordik, Patricia A; Hicks, M Lamar; Fouad, Ashraf F

2015-01-01

Although the internal anatomy of mandibular molars has been extensively studied, information about middle mesial (MM) canals is limited. The primary aim of this retrospective study was to evaluate the incidence of MM canals in mandibular first and second molars. The secondary aim was to correlate the incidence of MM canals with variables of molar type, sex, age, ethnicity, and presence of a second distal canal. All mature permanent first and second mandibular molars treated from August 2012 to May 2014 were included in the analysis. After completion of root canal instrumentation in all main canals, the clinician inspected the isthmus area of the mesial root using the dental operating microscope. If there was a catch point in this area with a file or explorer, the operator spent more time attempting to negotiate an MM canal. Seventy-five mandibular first and second molars were treated during the specified period. Fifteen (20%) teeth had negotiable MM canals. The incidence of MM canals was 32.1% in patients ≤ 20 years old, 23.8% in patients 21-40 years old, and 3.8% in patients > 40 years. Analysis of data revealed a significant difference in the distribution of MM canals among different age groups (P < .05). The differences in the distribution of MM canals based on sex, ethnicity, molar type, and presence of a second distal canal were not significant. The incidence of negotiable MM canals overall and their frequency of identification in younger patients were higher than in previous reports. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Gender and laterality in semicircular canal dehiscence syndrome.

PubMed

Karimnejad, K; Czerny, M S; Lookabaugh, S; Lee, D J; Mikulec, A A

2016-08-01

To determine if there is gender or laterality predilection in patients with semicircular canal dehiscence syndrome. A multi-institutional chart review was performed to identify patients diagnosed with semicircular canal dehiscence between 2000 and 2015. A systematic literature search was conducted using PubMed to further identify patients with semicircular canal dehiscence. Age, gender and laterality data were collected. Statistical analysis was performed to evaluate for gender or laterality preponderance. A total of 682 patients with semicircular canal dehiscence were identified by literature and chart review. Mean age of diagnosis was 49.75 years (standard deviation = 15.33). Semicircular canal dehiscence was associated with a statistically significant female predominance (chi-square = 7.185, p = 0.007); the female-to-male ratio was 1.2 to 1. Left-sided semicircular canal dehiscence was most common, followed by right-sided then bilateral (chi-square = 23.457, p < 0.001). Semicircular canal dehiscence syndrome is most commonly left-sided and exhibits a female predominance. This may be secondary to morphological cerebral hemisphere asymmetries in both sexes and a predilection of women to seek more medical care than men.

Determination of physical and dynamic properties of suspended particles in water column with ultrasonic scanning in between the water surface and stable sediment layer.

NASA Astrophysics Data System (ADS)

Acar, Dursun; Alpar, Bedri; Ozeren, Sinan; Cagatay, Namık; Sari, Erol; Vardar, Denizhan; Eris, Kadir

2015-04-01

The behavior of seafloor sediment with its water column should be known against any occurrences of anoxic or oxic conditions. The most important ones of these conditions are possible leakage of natural gas or escape of liquids from sediment. On the basis of combined solid/liquid flow dynamics in sedimentation, such kind of events can change, even in an effective manner, the dynamic movements of molecules and their cumulative mass of particules, i.e. the suspended materials. The deployment of suitable sediment traps or ultrasonic transducers somewhere in the water column are not easy attempts in order to obtain useful information about the state of suspended materials during sedimentation. These are usually bulky instruments; therefore they may behave like an anti-move suppresser on the particles moving in the float direction, in oxic and anoxic manner. These instruments, on the other hand, may cover the effects of diffusive flow or bubble formed gas and fluid escape from the sediment surface into the water column. Ultrasonic scanners, however, are able to make observations in a remote manner, without affecting such artificial events. Our field trials were successfully completed at the historical estuary called Halic of Marmara sea . The physical properties; such as the velocity of particles, their travel directions, their dimensions and the ability to observe anti-compositor crushes of shock waves of the bubbles are only a few of these observations in natural ambience. The most important problem solved about water pressure during 3 atmosphere . The sensor has been tested successfully few times. We used the ''High voltage electric isolator oil filling'' to the inside of the scanner for pressure equalization between outer side and inner body of probe at a depth of (20 meters) beneath the sea surface . The transmitted signals by the planar crystal of the transducer become weaker under the pressure of overlying water column in depths. Our efforts are now focused on the

Osmolarity and root canal antiseptics.

PubMed

Rossi-Fedele, G; Guastalli, A R

2014-04-01

Antiseptics used in endodontics for disinfection purposes include root canal dressings and irrigants. Osmotic shock is known to cause the alteration of microbial cell viability and might have a role in the mechanism of action of root canal antiseptics. The aim of this review was to determine the role of osmolarity on the performance of antiseptics in root canal treatment. A literature search using the Medline electronic database was conducted up to 30 May 2013 using the following search terms and combinations: 'osmolarity AND root canal or endodontic or antiseptic or irrigation or irrigant or medication or dressing or biofilm; osmolality AND root canal or endodontic or antiseptic or irrigation or irrigant or medication or dressing or biofilm; osmotic AND root canal or endodontic or antiseptic or irrigation or irrigant or medication or dressing or biofilm; osmosis AND root canal or endodontic or antiseptic or irrigation or irrigant or medication or dressing or biofilm; sodium chloride AND root canal or endodontic or antiseptic or irrigation or irrigant or medication or dressing or biofilm'. Publications were included if the effects of osmolarity on the clinical performance of antiseptics in root canal treatment were stated, if preparations with different osmolarities values were compared and if they were published in English. A hand search of articles published online, 'in press' and 'early view', and in the reference list of the included papers was carried out following the same criteria. A total of 3274 publications were identified using the database, and three were included in the review. The evidence available in endodontics suggests a possible role for hyperosmotic root canal medicaments as disinfectants, and that there is no influence of osmolarity on the tissue dissolution capacity of sodium hypochlorite. There are insufficient data to obtain a sound conclusion regarding the role of hypo-osmosis in root canal disinfection, or osmosis in any further desirable

Biochip scanner device

DOEpatents

Perov, Alexander; Belgovskiy, Alexander I.; Mirzabekov, Andrei D.

2001-01-01

A biochip scanner device used to detect and acquire fluorescence signal data from biological microchips or biochips and method of use are provided. The biochip scanner device includes a laser for emitting a laser beam. A modulator, such as an optical chopper modulates the laser beam. A scanning head receives the modulated laser beam and a scanning mechanics coupled to the scanning head moves the scanning head relative to the biochip. An optical fiber delivers the modulated laser beam to the scanning head. The scanning head collects the fluorescence light from the biochip, launches it into the same optical fiber, which delivers the fluorescence into a photodetector, such as a photodiode. The biochip scanner device is used in a row scanning method to scan selected rows of the biochip with the laser beam size matching the size of the immobilization site.

Recent micro-CT scanner developments at UGCT

NASA Astrophysics Data System (ADS)

Dierick, Manuel; Van Loo, Denis; Masschaele, Bert; Van den Bulcke, Jan; Van Acker, Joris; Cnudde, Veerle; Van Hoorebeke, Luc

2014-04-01

This paper describes two X-ray micro-CT scanners which were recently developed to extend the experimental possibilities of microtomography research at the Centre for X-ray Tomography (www.ugct.ugent.be) of the Ghent University (Belgium). The first scanner, called Nanowood, is a wide-range CT scanner with two X-ray sources (160 kVmax) and two detectors, resolving features down to 0.4 μm in small samples, but allowing samples up to 35 cm to be scanned. This is a sample size range of 3 orders of magnitude, making this scanner well suited for imaging multi-scale materials such as wood, stone, etc. Besides the traditional cone-beam acquisition, Nanowood supports helical acquisition, and it can generate images with significant phase-contrast contributions. The second scanner, known as the Environmental micro-CT scanner (EMCT), is a gantry based micro-CT scanner with variable magnification for scanning objects which are not easy to rotate in a standard micro-CT scanner, for example because they are physically connected to external experimental hardware such as sensor wiring, tubing or others. This scanner resolves 5 μm features, covers a field-of-view of about 12 cm wide with an 80 cm vertical travel range. Both scanners will be extensively described and characterized, and their potential will be demonstrated with some key application results.

Analytical Ultrasonics in Materials Research and Testing

NASA Technical Reports Server (NTRS)

Vary, A.

1986-01-01

Research results in analytical ultrasonics for characterizing structural materials from metals and ceramics to composites are presented. General topics covered by the conference included: status and advances in analytical ultrasonics for characterizing material microstructures and mechanical properties; status and prospects for ultrasonic measurements of microdamage, degradation, and underlying morphological factors; status and problems in precision measurements of frequency-dependent velocity and attenuation for materials analysis; procedures and requirements for automated, digital signal acquisition, processing, analysis, and interpretation; incentives for analytical ultrasonics in materials research and materials processing, testing, and inspection; and examples of progress in ultrasonics for interrelating microstructure, mechanical properites, and dynamic response.

Regulation of X-Ray Security Scanners in Michigan.

PubMed

Parry, Donald E

2016-02-01

In January of 2013 the Transportation Security Administration (TSA) ordered the removal of x-ray security scanners from airports by June of 2013. Since that time several of these scanners have been purchased at a reduced cost by various state and county governments for use in screening individuals entering or leaving their facilities. To address this issue the Radiation Safety Section of the State of Michigan drafted a set of registration conditions for facilities to follow when using these security scanners. Inspection procedures and measurement protocols were developed to estimate the dose to screened individuals. Inspections were performed on nine of the 16 registered backscatter scanners in the state and the one transmission scanner. The average estimated effective dose to screened individuals was ∼11 nSv for a two view scan from a backscatter system. The effective dose was 0.446 μSv, 0.330 μSv, and 0.150 μSv for a transmission system operated in the high, medium, and low dose modes, respectively. The limit suggested in the new registration condition is 0.25 μSv for a general use system and 10 μSv for a limited use system.

Reconstruction artifacts in VRX CT scanner images

NASA Astrophysics Data System (ADS)

Rendon, David A.; DiBianca, Frank A.; Keyes, Gary S.

2008-03-01

Variable Resolution X-ray (VRX) CT scanners allow imaging of different sized anatomy at the same level of detail using the same device. This is achieved by tilting the x-ray detectors so that the projected size of the detecting elements is varied to produce reconstructions of smaller fields of view with higher spatial resolution. As with regular CT scanners, the images obtained with VRX scanners are affected by different kinds of artifacts of various origins. This work studies some of these artifacts and the impact that the VRX effect has on them. For this, computational models of single-arm single-slice VRX scanners are used to produce images with artifacts commonly found in routine use. These images and artifacts are produced using our VRX CT scanner simulator, which allows us to isolate the system parameters that have a greater effect on the artifacts. A study of the behavior of the artifacts at varying VRX opening angles is presented for scanners implemented using two different detectors. The results show that, although varying the VRX angle will have an effect on the severity of each of the artifacts studied, for some of these artifacts the effect of other factors (such as the distribution of the detector cells and the position of the phantom in the reconstruction grid) is overwhelmingly more significant. This is shown to be the case for streak artifacts produced by thin metallic objects. For some artifacts related to beam hardening, their severity was found to decrease along with the VRX angle. These observations allow us to infer that in regular use the effect of the VRX angle artifacts similar to the ones studied here will not be noticeable as it will be overshadowed by parameters that cannot be easily controlled outside of a computational model.

Hybrid Dispersion Laser Scanner

PubMed Central

Goda, K.; Mahjoubfar, A.; Wang, C.; Fard, A.; Adam, J.; Gossett, D. R.; Ayazi, A.; Sollier, E.; Malik, O.; Chen, E.; Liu, Y.; Brown, R.; Sarkhosh, N.; Di Carlo, D.; Jalali, B.

2012-01-01

Laser scanning technology is one of the most integral parts of today's scientific research, manufacturing, defense, and biomedicine. In many applications, high-speed scanning capability is essential for scanning a large area in a short time and multi-dimensional sensing of moving objects and dynamical processes with fine temporal resolution. Unfortunately, conventional laser scanners are often too slow, resulting in limited precision and utility. Here we present a new type of laser scanner that offers ∼1,000 times higher scan rates than conventional state-of-the-art scanners. This method employs spatial dispersion of temporally stretched broadband optical pulses onto the target, enabling inertia-free laser scans at unprecedented scan rates of nearly 100 MHz at 800 nm. To show our scanner's broad utility, we use it to demonstrate unique and previously difficult-to-achieve capabilities in imaging, surface vibrometry, and flow cytometry at a record 2D raster scan rate of more than 100 kHz with 27,000 resolvable points. PMID:22685627

Unusual Root Canal Irrigation Solutions.

PubMed

Mohammadi, Zahed; Jafarzadeh, Hamid; Shalavi, Sousan; Kinoshita, Jun-Ichiro

2017-05-01

Microorganisms and their by-products play a critical role in pulp and periradicular pathosis. Therefore, one of the main purposes of root canal treatment is disinfection of the entire system of the canal. This aim may be obtained using mechanical preparation, chemical irrigation, and temporary medication of the canal. For this purpose, various irrigation solutions have been advocated. Common root canal irrigants, such as sodium hypochlorite, chlorhexidine, and a mixture of tetracycline, acid, and detergent have been extensively reviewed. The aim of this review was to address the less common newer root canal irrigation solutions, such as citric acid, maleic acid, electrochemically activated water, green tea, ozonated water, and SmearClear.

[Tolerance of magnetic resonance imaging in children and adolescents performed in a 1.5 Tesla MR scanner with an open design].

PubMed

Adamietz, B; Cavallaro, A; Radkow, T; Alibek, S; Holter, W; Bautz, W A; Staatz, G

2007-08-01

To investigate the tolerance of MR examinations in children and adolescents performed in a 1.5 Tesla MR scanner with an expanded bore diameter. 163 patients, ages 4 to 25, underwent MR examinations in a 1.5 Tesla MR scanner with an open design (MAGNETOM Espree, Siemens, Erlangen, Germany), characterized by a compact length of 125 cm and an expanded 70 cm bore diameter. MR imaging of the brain was carried out in most cases (78.5 %), followed by examinations of the spinal canal (9.8 %), the extremities (9.2 %) and the neck (2.5 %). The patients were divided into four age groups and the success rate, motion artifacts and diagnostic quality of the MR examinations were assessed using a 3-grade scale. In 119 of 163 patients (73.0 %), MR examination was possible without any motion artifacts. With respect to the different age groups, 41.7 % of the 4 - 7-year-old children, 67.6 % of the 8 - 10-year-old children, 84.1 % of the 11 - 16-year-old children and 95.8 % of the patients older than 17 showed tolerance grade I without motion artifacts and excellent diagnostic image quality. In 39 of 163 children (23.9 %), the MR images showed moderate motion artifacts but had sufficient diagnostic quality. With regard to the different age groups, 52.8 % of the 4 - 7-year-old children, 26.5 % of the 8 - 10-year-old children, 15.9 % of the 11 - 16-year-old children and none of the patients older than 17 showed tolerance grade II with moderate motion artifacts and sufficient diagnostic image quality. In only 4 of 124 children < 10 years old and 1 child > 10 years old, the MR examination was not feasible and had to be repeated under sedation. Pediatric MR imaging using a 1.5 Tesla MR scanner with an open design can be conducted in children and adolescents with excellent acceptance. The failure rate of 3.0 % of cases for pediatric MR imaging is comparable to that of a conventional low-field open MR scanner.

Influence of operator experience on canal preparation time when using the rotary Ni-Ti ProFile system in simulated curved canals.

PubMed

Mesgouez, C; Rilliard, F; Matossian, L; Nassiri, K; Mandel, E

2003-03-01

The aim of this study was to determine the influence of operator experience on the time needed for canal preparation when using a rotary nickel-titanium (Ni-Ti) system. A total of 100 simulated curved canals in resin blocks were used. Four operators prepared a total of 25 canals each. The operators included practitioners with prior experience of the preparation technique, and practitioners with no experience. The working length for each instrument was precisely predetermined. All canals were instrumented with rotary Ni-Ti ProFile Variable Taper Series 29 engine-driven instruments using a high-torque handpiece (Maillefer, Ballaigues, Switzerland). The time taken to prepare each canal was recorded. Significant differences between the operators were analysed using the Student's t-test and the Kruskall-Wallis and Dunn nonparametric tests. Comparison of canal preparation times demonstrated a statistically significant difference between the four operators (P < 0.001). In the inexperienced group, a significant linear regression between canal number and preparation time occurred. Time required for canal preparation was inversely related to operator experience.

Input Scanners: A Growing Impact In A Diverse Marketplace

NASA Astrophysics Data System (ADS)

Marks, Kevin E.

1989-08-01

Just as newly invented photographic processes revolutionized the printing industry at the turn of the century, electronic imaging has affected almost every computer application today. To completely emulate traditionally mechanical means of information handling, computer based systems must be able to capture graphic images. Thus, there is a widespread need for the electronic camera, the digitizer, the input scanner. This paper will review how various types of input scanners are being used in many diverse applications. The following topics will be covered: - Historical overview of input scanners - New applications for scanners - Impact of scanning technology on select markets - Scanning systems issues

Adjunctive Steps for Disinfection of the Mandibular Molar Root Canal System: A Correlative Bacteriologic, Micro-Computed Tomography, and Cryopulverization Approach.

PubMed

Alves, Flávio R F; Andrade-Junior, Carlos V; Marceliano-Alves, Marília F; Pérez, Alejandro R; Rôças, Isabela N; Versiani, Marco A; Sousa-Neto, Manoel D; Provenzano, José C; Siqueira, José F

2016-11-01

This study evaluated the disinfecting ability of chemomechanical preparation with rotary nickel-titanium instruments, followed by 2 distinct adjunctive procedures in the root canals of extracted mandibular molars by means of a correlative analytical approach. Twenty-two extracted mandibular molars were selected and anatomically matched between groups on the basis of micro-computed tomographic analysis. In the first phase of the experiment, root canals were contaminated with Enterococcus faecalis and subjected to chemomechanical preparation with BT RaCe instruments and 2.5% NaOCl irrigation. Then either XP-Endo Finisher instrument or passive ultrasonic irrigation was used to supplement disinfection. Micro-computed tomography was used to show whether the percentage of unprepared areas correlated to bacterial counts. In the second phase, the same teeth were contaminated once again, and the adjunctive procedures were used. Samples from the isthmus area of mesial roots and the apical 5-mm fragment of distal roots were obtained by cryopulverization. Samples taken before and after treatment steps in both phases were evaluated by quantitative polymerase chain reaction and statistically analyzed. In phase 1, preparation in both groups resulted in substantial decrease of bacterial counts (P < .001). The adjunctive approaches led to a further small bacterial reduction, which was significant for XP-Endo Finisher (P < .05). No significant differences were observed between groups for persisting bacterial counts. Correlative analysis revealed no statistically significant relationship between bacterial reduction and the percentage of unprepared areas (P > .05). In phase 2, both methods had significant antibacterial effects in the main canal, but none of them could predictably disinfect the isthmus/recess areas. Both XP-Endo Finisher and passive ultrasonic irrigation exhibited antibacterial effectiveness, but only the former caused a significant reduction in the bacterial

Limitations of navigation through Nubaria canal, Egypt.

PubMed

Samuel, Magdy G

2014-03-01

Alexandria port is the main Egyptian port at the Mediterranean Sea. It is connected to the Nile River through Nubaria canal, which is a main irrigation canal. The canal was designed to irrigate eight hundred thousand acres of agricultural lands, along its course which extends 100 km. The canal has three barrages and four locks to control the flow and allow light navigation by some small barges. Recently, it was decided to improve the locks located on the canal. More than 40 million US$ was invested in these projects. This decision was taken to allow larger barges and increase the transported capacity through the canal. On the other hand, navigation through canals and restricted shallow waterways is affected by several parameters related to both the channel and the vessel. Navigation lane width as well as vessel speed and maneuverability are affected by both the channel and vessel dimensions. Moreover, vessel dimensions and speed will affect the canal stability. In Egypt, there are no guide rules for navigation through narrow and shallow canals such Nubaria. This situation threatens the canal stability and safety of navigation through it. This paper discussed the characteristics of Nubaria canal and the guide rules for navigation in shallow restricted water ways. Dimensions limitation for barges navigating through Nubaria canal is presented. New safe operation rules for navigation in Nubaria canal are also presented. Moreover, the implication of navigation through locks on canal discharge is estimated.

Effect of Ultrasonic Frequency on Lactic Acid Fermentation Promotion by Ultrasonic Irradiation

NASA Astrophysics Data System (ADS)

Shimada, Tadayuki; Ohdaira, Etsuzo; Masuzawa, Nobuyoshi

2004-05-01

The authors have been researching the promotion of lactic acid fermentation by ultrasonic irradiation. In the past research, it was proven that ultrasonic irradiation is effective in the process of fermentation, and the production of yoghurt and kefir was promoted. In this study, the effect of the ultrasonic frequency in this fermentation process was examined. In the frequency range of this study, it was found that the action of fermentation promotion was exponentially proportionate to the irradiated ultrasonic frequency.

Atrioventricular Canal Defect

MedlinePlus

... birth (congenital). The condition is often associated with Down syndrome. Atrioventricular canal defect allows extra blood to flow ... baby's heart is developing. Some factors, such as Down syndrome, might increase the risk of atrioventricular canal defect. ...

2. View looking northeast; Dundee Canal headgates and guardlock in ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. View looking northeast; Dundee Canal headgates and guardlock in foreground, Dundee Dam and Passaic River in background - Dundee Canal Industrial Historic District, Beginning at George Street in Passaic & extending north along Dundee Canal approximately 1.2 miles to Canal headgates opposite East Clifton Avenue in Clifton, Passaic, Passaic County, NJ

CT detection of facial canal dehiscence and semicircular canal fistula: Comparison with surgical findings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fuse, Takeo; Tada, Yuichiro; Aoyagi, Masaru

1996-03-01

The purpose of this study was to determine the accuracy of high resolution CT (HRCT) in the detection of facial canal dehiscence and semicircular canal fistula, the preoperative evaluation of both of which is clinically very important for ear surgery. We retrospectively reviewed the HRCT findings in 61 patients who underwent mastoidectomy at Yamagata University between 1989 and 1993. The HRCT images were obtained in the axial and semicoronal planes using 1 mm slice thickness and 1 mm intersection gap. In 46 (75%) of the 61 patients, the HRCT image-based assessment of the facial canal dehiscence coincided with the surgicalmore » findings. The data for the facial canal revealed sensitivity of 66% and specificity of 84%. For semicircular canal fistula. in 59 (97%) of the 61 patients, the HRCT image-based assessment and the surgical findings coincided. The image-based assessment in the remaining two patients, who both had massive cholesteatoma, was false-positive. HRCT is useful in the diagnosis of facial canal dehiscence and labyrinthine fistula, but its limitations should also be recognized. 12 refs., 3 figs., 6 tabs.« less

Ultrasonic Maintenance

NASA Technical Reports Server (NTRS)

1991-01-01

The Ultraprobe 2000, manufactured by UE Systems, Inc., Elmsford, NY, is a hand-held ultrasonic system that detects indications of bearing failure by analyzing changes in amplitude. It employs the technology of a prototype ultrasonic bearing-failure monitoring system developed by Mechanical Technology, Inc., Latham, New York and Marshall Space Flight Center (which was based on research into Skylab's gyroscope bearings). Bearings on the verge of failure send ultrasonic signals indicating their deterioration; the Ultraprobe changes these to audible signals. The operator hears the signals and gages their intensity with a meter in the unit.

A randomized, blinded study of canal wall up versus canal wall down mastoidectomy determining the differences in viewing middle ear anatomy and pathology.

PubMed

Hulka, G F; McElveen, J T

1998-09-01

Canal wall down and intact canal wall tympanomastoidectomy represent two surgical approaches to middle ear pathology. The authors hypothesize that there is a difference in the ability to view structures in the middle ear between these two methods. Depending on the individual, many surgeons have used the two different techniques of intact canal wall and canal wall down tympanomastoidectomy for approaching the middle ear. However, opinions conflict as to which approach provides the best visualization of different locations in the middle ear. This study prospectively evaluated temporal bones to determine the differences in visualizing structures of the middle ear using these two approaches. Twelve temporal bones underwent a standardized canal wall down tympanomastoidectomy using a reversible canal wall down technique. All bones were viewed in two dissections: intact canal wall and canal wall down preparations. Four points previously had been marked on each temporal bone in randomly assigned colors. These points include the sinus tympani, posterior crus of stapes, lateral epitympanum, and the Eustachian tube orifice. An observer blinded to the purpose of the study, color, and number of locations recorded the color and location of marks observed within the temporal bones. Randomized bones of two separate settings were viewed such that each bone was viewed in both the canal wall down and the intact canal wall preparations. A significant difference was noted in the ability to observe middle ear pathology between the intact canal wall versus canal wall down tympanomastoidectomy, with the latter showing superiority (p < 0.001). Of the four subsites, the sinus tympani, posterior crus of stapes, and lateral epitympanum were observed more frequently with the canal wall down. There was no significant difference in the ability to observe the Eustachian tube orifice between the two techniques. Statistical analysis shows good reproducibility and randomization of this study. The

Functional Implications of Ubiquitous Semicircular Canal Non-Orthogonality in Mammals

PubMed Central

Berlin, Jeri C.; Kirk, E. Christopher; Rowe, Timothy B.

2013-01-01

The ‘canonical model’ of semicircular canal orientation in mammals assumes that 1) the three ipsilateral canals of an inner ear exist in orthogonal planes (i.e., orthogonality), 2) corresponding left and right canal pairs have equivalent angles (i.e., angle symmetry), and 3) contralateral synergistic canals occupy parallel planes (i.e., coplanarity). However, descriptions of vestibular anatomy that quantify semicircular canal orientation in single species often diverge substantially from this model. Data for primates further suggest that semicircular canal orthogonality varies predictably with the angular head velocities encountered in locomotion. These observations raise the possibility that orthogonality, symmetry, and coplanarity are misleading descriptors of semicircular canal orientation in mammals, and that deviations from these norms could have significant functional consequences. Here we critically assess the canonical model of semicircular canal orientation using high-resolution X-ray computed tomography scans of 39 mammal species. We find that substantial deviations from orthogonality, angle symmetry, and coplanarity are the rule for the mammals in our comparative sample. Furthermore, the degree to which the semicircular canals of a given species deviate from orthogonality is negatively correlated with estimated vestibular sensitivity. We conclude that the available comparative morphometric data do not support the canonical model and that its overemphasis as a heuristic generalization obscures a large amount of functionally relevant variation in semicircular canal orientation between species. PMID:24260256

Antibacterial Efficacy of a New Sonic Irrigation Device for Root Canal Disinfection.

PubMed

Neuhaus, Klaus W; Liebi, Melanie; Stauffacher, Simone; Eick, Sigrun; Lussi, Adrian

2016-12-01

Passive ultrasonic irrigation (PUI) is the most widespread method used to activate irrigation solutions. Concerns have been raised that PUI is less effective in curved root canals and is not passive at all. Our aim was to compare a novel passive sonic irrigation (PSI) device (6000 Hz) with PUI and manual irrigation (MI) with respect to their efficiency in removing different endodontic microorganisms from curved and straight root canals. We performed 2 experiments as follows. In a 3-day infection model, we included 8 groups of single or dual microbial species that were rinsed with 0.9% sodium chloride using PSI, PUI, or MI. Colony-forming units (CFUs) were counted after incubation, and log 10 transformations were performed for statistical comparisons. In a 21-d infection model, we tested the same irrigation protocols on 4 groups of microorganisms and used 1.5% sodium hypochlorite as an irrigant. Infection control samples were taken at day 0, 3, 5, and 7 after treatment and were subsequently reincubated. Using sodium chloride as an irrigant, the amount of reduction in CFUs compared with the negative control was approximately 3 log 10 units for PSI at 6000 Hz, 2 log 10 units for PUI, and 1 log 10 unit for MI. PSI reduced the microorganism CFUs significantly better than PUI. Using sodium hypochlorite led to a significant reduction in microorganism CFUs even with MI. After 3 days, compared with MI, microorganism regrowth significantly reduced after PSI and PUI treatment, but in these groups, in at least half of the samples, microorganisms were detectable after 7 days. PSI at 6000 Hz might be at least equal to PUI with respect to reduction of the microbial load in curved and straight root canals. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Decline in semicircular canal and otolith function with age

PubMed Central

Agrawal, Yuri; Zuniga, M. Geraldine; Davalos-Bichara, Marcela; Schubert, Michael C.; Walston, Jeremy D.; Hughes, Jennifer; Carey, John P.

2012-01-01

Objective To characterize the physiologic nature of the vestibular dysfunction that occurs with the normative aging process. Study design Cross-sectional study. Setting Tertiary care academic medical center. Patients Fifty individuals age 70 and above. Interventions Head thrust dynamic visual acuity testing (htDVA) and cervical and ocular vestibular-evoked myogenic potential (VEMP) testing. Main Outcome Measures Semicircular canal function measured by htDVA in each of the three semicircular canal planes, and saccular and utricular function measured by cVEMP and oVEMP testing, respectively. Results We observed significant declines in semicircular canal function in each of the canal planes as well as otolith function associated with aging. We found that individuals with impaired horizontal and superior semicircular canal function were likely to also have concomitant deficits in utricular but not saccular function. Overall, we noted that the prevalence of semicircular canal dysfunction was highest followed by saccular then utricular impairment, although we did observe individuals with isolated otolith deficits. Conclusions These data suggest an overall decline in semicircular canal as well as otolith function associated with aging, although the magnitude of impairment was greater for the semicircular canals than the otoliths in this elderly population. A better understanding of the specific vestibular deficits that occur with aging can inform the development of rational screening, vestibular rehabilitation and fall risk reduction strategies in older individuals. PMID:22699991

Love Canal: environmental and toxicological studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, C.S.

The New York State Department of Health has been involved at the Love Canal since 1978. The State has carried out numerous environmental and toxicological studies. The major purposes for these studies were to define how Love Canal contaminants might be escaping into the environment at large, what paths contaminant migration might take, and what toxicological effects Love Canal chemicals might have individually and together. Although underground contaminant migration was hypothesized along swales and underground utility bedding, these mechanisms have been proven not to be operative except for some migration along the utility bedding under Frontier Avenue. In general nomore » underground migration has occurred outside the confines of the three city blocks that contain the Love Canal referred to as the ''first ring''. Studies have been confused by apparent burial of waste materials in areas proximate but not directly connected to the Love Canal. Migration of Love Canal leachate has occurred through storm sewers. Love Canal contaminants have reached creeks to the north and the Niagara River to the south through storm sewer transport. In spite of finding 2, 3, 7, 8 tetrachlorodibenzoparadioxin (TCDD), toxicological studies in situ and through exposure to volatile components in Love Canal soils do not indicate unusual toxicity. Animal studies continue in an attempt to determine the teratogenic and fetotoxic potential of Love Canal chemicals under different routes of exposure.« less

Ultrasonic Motors

DTIC Science & Technology

2003-06-01

micromotor have been investigated. The piezoelectric motor makes use of two orthogonal bending modes of a hollow cylinder. The vibrating element...A.Iino, K.Suzuki, M.Kasuga, M.Suzuki and T.Yamanaka, "Development of a Self- Oscillating Ultrasonic Micromotor and Its Application to a Watch...pp. 823-828, 1997. [12] M. K. Kurosawa, T. Morita, and T. Higuchi, "A Cylindrical Ultrasonic Micromotor Based on PZT Thin Film," IEEE Ultrasonics

Influence of a glide path on apical extrusion of debris during canal preparation using single-file systems in curved canals.

PubMed

Topçuoğlu, H S; Düzgün, S; Akpek, F; Topçuoğlu, G; Aktı, A

2016-06-01

To evaluate the effect of a glide path on the amount of apically extruded debris during canal preparation using single-file systems in curved canals. Ninety extracted mandibular molar teeth were randomly assigned to six groups (n = 15 for each group) for canal instrumentation. Endodontic access cavities were prepared in each tooth. In three of the six groups, a glide path was not created whereas a glide path was created using PathFile instruments on the mesial canals of all teeth in the remaining three groups. The mesial canals of the teeth were then instrumented with the following single-file instrument systems: WaveOne, Reciproc and OneShape. Debris extruded apically during instrumentation was collected into pre-weighed Eppendorf tubes. The tubes were then stored in an incubator at 70 °C for 5 days. The weight of the dry extruded debris was established by subtracting the pre-instrumentation and post-instrumentation weight of the Eppendorf tubes for each group. The data obtained were analysed using one-way analysis of variance (anova) and Tukey's post hoc tests. The OneShape file was associated with less debris extrusion than the Reciproc and WaveOne files when canal instrumentation was performed without a glide path (P < 0.05). However, no significant difference was found between the Reciproc and WaveOne files (P > 0.05). There was no significant difference amongst the OneShape, Reciproc and WaveOne files when a glide path was created before canal preparation in curved root canals (P > 0.05). All systems extruded significantly less debris in groups with a glide path than in groups without a glide path (P < 0.05). All instruments were associated with apical extrusion of debris. Creating a glide path prior to canal instrumentation reduced the amount of apically extruded debris in curved canals. © 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.

A novel optical scanner for laser radar

NASA Astrophysics Data System (ADS)

Yao, Shunyu; Peng, Renjun; Gao, Jianshuang

2013-09-01

Laser radar are ideally suitable for recognizing objects, detection, target tracking or obstacle avoidance, because of the high angular and range resolution. In recent years, scannerless ladar has developed rapidly. In contrast with traditional scanner ladar, scannerless ladar has distinct characteristics such as small, compact, high frame rate, wide field of view and high reliability. However, the scannerless ladar is still in the stage of laboratory and the performance cannot meet the demands of practical applications. Hence, traditional scanner laser radar is still mainly applied. In scanner ladar system, optical scanner is the key component which can deflect the direction of laser beam to the target. We investigated a novel scanner based on the characteristic of fiber's light-conductive. The fiber bundles are arranged in a special structure which connected to a motor. When motor working properly, the laser passes through the fibers on incident plane and the location of laser spot on output plane will move along with a straight line in a constant speed. The direction of light will be deflected by taking advantage of transmitting optics, then the linear sweeping of the target can be achieved. A laser radar scheme with high speed and large field of view can be realized. Some researches on scanner are simply introduced on section1. The structure of the optical scanner will be described and the practical applications of the scanner in transmitting and receiving optical paths are discussed in section2. Some characteristic of scanner is calculated in section3. In section4, we report the simulation and experiment of our prototype.

Integrated Electro-optical Laser-Beam Scanners

NASA Technical Reports Server (NTRS)

Boord, Warren T.

1990-01-01

Scanners using solid-state devices compact, consume little power, and have no moving parts. Integrated electro-optical laser scanner, in conjunction with external lens, points outgoing beam of light in any number of different directions, depending on number of upper electrodes. Offers beam-deflection angles larger than those of acousto-optic scanners. Proposed for such diverse applications as nonimpact laser printing, color imaging, ranging, barcode reading, and robotic vision.

Radial vibration and ultrasonic field of a long tubular ultrasonic radiator.

PubMed

Shuyu, Lin; Zhiqiang, Fu; Xiaoli, Zhang; Yong, Wang; Jing, Hu

2013-09-01

The radial vibration of a metal long circular tube is studied analytically and its electro-mechanical equivalent circuit is obtained. Based on the equivalent circuit, the radial resonance frequency equation is derived. The theoretical relationship between the radial resonance frequency and the geometrical dimensions is studied. Finite element method is used to simulate the radial vibration and the radiated ultrasonic field and the results are compared with those from the analytical method. It is concluded that the radial resonance frequency for a solid metal rod is larger than that for a metal tube with the same outer radius. The radial resonance frequencies from the analytical method are in good agreement with those from the numerical method. Based on the acoustic field analysis, it is concluded that the long metal tube with small wall thickness is superior to that with large wall thickness in producing radial vibration and ultrasonic radiation. Therefore, it is expected to be used as an effective radial ultrasonic radiator in ultrasonic sewage treatment, ultrasonic antiscale and descaling and other ultrasonic liquid handling applications. Copyright © 2013 Elsevier B.V. All rights reserved.

Accuracy in contouring of small and low contrast lesions: Comparison between diagnostic quality computed tomography scanner and computed tomography simulation scanner-A phantom study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ho, Yick Wing, E-mail: mpr@hksh.com; Wong, Wing Kei Rebecca; Yu, Siu Ki

2012-01-01

To evaluate the accuracy in detection of small and low-contrast regions using a high-definition diagnostic computed tomography (CT) scanner compared with a radiotherapy CT simulation scanner. A custom-made phantom with cylindrical holes of diameters ranging from 2-9 mm was filled with 9 different concentrations of contrast solution. The phantom was scanned using a 16-slice multidetector CT simulation scanner (LightSpeed RT16, General Electric Healthcare, Milwaukee, WI) and a 64-slice high-definition diagnostic CT scanner (Discovery CT750 HD, General Electric Healthcare). The low-contrast regions of interest (ROIs) were delineated automatically upon their full width at half maximum of the CT number profile inmore » Hounsfield units on a treatment planning workstation. Two conformal indexes, CI{sub in}, and CI{sub out}, were calculated to represent the percentage errors of underestimation and overestimation in the automated contours compared with their actual sizes. Summarizing the conformal indexes of different sizes and contrast concentration, the means of CI{sub in} and CI{sub out} for the CT simulation scanner were 33.7% and 60.9%, respectively, and 10.5% and 41.5% were found for the diagnostic CT scanner. The mean differences between the 2 scanners' CI{sub in} and CI{sub out} were shown to be significant with p < 0.001. A descending trend of the index values was observed as the ROI size increases for both scanners, which indicates an improved accuracy when the ROI size increases, whereas no observable trend was found in the contouring accuracy with respect to the contrast levels in this study. Images acquired by the diagnostic CT scanner allow higher accuracy on size estimation compared with the CT simulation scanner in this study. We recommend using a diagnostic CT scanner to scan patients with small lesions (<1 cm in diameter) for radiotherapy treatment planning, especially for those pending for stereotactic radiosurgery in which accurate delineation of

Ultrasonic Bolt Gage

NASA Technical Reports Server (NTRS)

Gleman, Stuart M. (Inventor); Rowe, Geoffrey K. (Inventor)

1999-01-01

An ultrasonic bolt gage is described which uses a crosscorrelation algorithm to determine a tension applied to a fastener, such as a bolt. The cross-correlation analysis is preferably performed using a processor operating on a series of captured ultrasonic echo waveforms. The ultrasonic bolt gage is further described as using the captured ultrasonic echo waveforms to perform additional modes of analysis, such as feature recognition. Multiple tension data outputs, therefore, can be obtained from a single data acquisition for increased measurement reliability. In addition, one embodiment of the gage has been described as multi-channel, having a multiplexer for performing a tension analysis on one of a plurality of bolts.

Ultrasonic speech translator and communications system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Akerman, M.A.; Ayers, C.W.; Haynes, H.D.

1996-07-23

A wireless communication system undetectable by radio frequency methods for converting audio signals, including human voice, to electronic signals in the ultrasonic frequency range, transmitting the ultrasonic signal by way of acoustical pressure waves across a carrier medium, including gases, liquids, or solids, and reconverting the ultrasonic acoustical pressure waves back to the original audio signal. The ultrasonic speech translator and communication system includes an ultrasonic transmitting device and an ultrasonic receiving device. The ultrasonic transmitting device accepts as input an audio signal such as human voice input from a microphone or tape deck. The ultrasonic transmitting device frequency modulatesmore » an ultrasonic carrier signal with the audio signal producing a frequency modulated ultrasonic carrier signal, which is transmitted via acoustical pressure waves across a carrier medium such as gases, liquids or solids. The ultrasonic receiving device converts the frequency modulated ultrasonic acoustical pressure waves to a frequency modulated electronic signal, demodulates the audio signal from the ultrasonic carrier signal, and conditions the demodulated audio signal to reproduce the original audio signal at its output. 7 figs.« less

Ultrasonic speech translator and communications system

DOEpatents

Akerman, M.A.; Ayers, C.W.; Haynes, H.D.

1996-07-23

A wireless communication system undetectable by radio frequency methods for converting audio signals, including human voice, to electronic signals in the ultrasonic frequency range, transmitting the ultrasonic signal by way of acoustical pressure waves across a carrier medium, including gases, liquids, or solids, and reconverting the ultrasonic acoustical pressure waves back to the original audio signal. The ultrasonic speech translator and communication system includes an ultrasonic transmitting device and an ultrasonic receiving device. The ultrasonic transmitting device accepts as input an audio signal such as human voice input from a microphone or tape deck. The ultrasonic transmitting device frequency modulates an ultrasonic carrier signal with the audio signal producing a frequency modulated ultrasonic carrier signal, which is transmitted via acoustical pressure waves across a carrier medium such as gases, liquids or solids. The ultrasonic receiving device converts the frequency modulated ultrasonic acoustical pressure waves to a frequency modulated electronic signal, demodulates the audio signal from the ultrasonic carrier signal, and conditions the demodulated audio signal to reproduce the original audio signal at its output. 7 figs.

Ultrasonic speech translator and communications system

DOEpatents

Akerman, M. Alfred; Ayers, Curtis W.; Haynes, Howard D.

1996-01-01

A wireless communication system undetectable by radio frequency methods for converting audio signals, including human voice, to electronic signals in the ultrasonic frequency range, transmitting the ultrasonic signal by way of acoustical pressure waves across a carrier medium, including gases, liquids, or solids, and reconverting the ultrasonic acoustical pressure waves back to the original audio signal. The ultrasonic speech translator and communication system (20) includes an ultrasonic transmitting device (100) and an ultrasonic receiving device (200). The ultrasonic transmitting device (100) accepts as input (115) an audio signal such as human voice input from a microphone (114) or tape deck. The ultrasonic transmitting device (100) frequency modulates an ultrasonic carrier signal with the audio signal producing a frequency modulated ultrasonic carrier signal, which is transmitted via acoustical pressure waves across a carrier medium such as gases, liquids or solids. The ultrasonic receiving device (200) converts the frequency modulated ultrasonic acoustical pressure waves to a frequency modulated electronic signal, demodulates the audio signal from the ultrasonic carrier signal, and conditions the demodulated audio signal to reproduce the original audio signal at its output (250).

Hypoglossal canal size and hominid speech

PubMed Central

DeGusta, David; Gilbert, W. Henry; Turner, Scott P.

1999-01-01

The mammalian hypoglossal canal transmits the nerve that supplies the motor innervation to the tongue. Hypoglossal canal size has previously been used to date the origin of human-like speech capabilities to at least 400,000 years ago and to assign modern human vocal abilities to Neandertals. These conclusions are based on the hypothesis that the size of the hypoglossal canal is indicative of speech capabilities. This hypothesis is falsified here by the finding of numerous nonhuman primate taxa that have hypoglossal canals in the modern human size range, both absolutely and relative to oral cavity volume. Specimens of Australopithecus afarensis, Australopithecus africanus, and Australopithecus boisei also have hypoglossal canals that, both absolutely and relative to oral cavity volume, are equal in size to those of modern humans. The basis for the hypothesis that hypoglossal canal size is indicative of speech was the assumption that hypoglossal canal size is correlated with hypoglossal nerve size, which in turn is related to tongue function. This assumption is probably incorrect, as we found no apparent correlation between the size of the hypoglossal nerve, or the number of axons it contains, and the size of the hypoglossal canal in a sample of cadavers. Our data demonstrate that the size of the hypoglossal canal does not reflect vocal capabilities or language usage. Thus the date of origin for human language and the speech capabilities of Neandertals remain open questions. PMID:9990105

Efficacy of passive ultrasonic irrigation with natural irrigants (Morinda citrifolia juice, Aloe Vera and Propolis) in comparison with 1% sodium hypochlorite for removal of E. faecalis biofilm: an in vitro study.

PubMed

Bhardwaj, Anuj; Velmurugan, Natanasabapathy; Ballal, Suma

2013-01-01

Present study evaluated the efficacy of natural derivative irrigants, Morinda citrifolia juice (MCJ), Aloe Vera and Propolis in comparison to 1% sodium hypochlorite with passive ultrasonic irrigation for removal of the intraradicular E. faecalis biofilms in extracted single rooted human permanent teeth. Biofilms of E. faecalis were grown on the prepared root canal walls of 60 standardized root halves which were longitudinally sectioned. These root halves were re-approximated and the samples were divided into five groups of twelve each. The groups were, Group A (1% NaOCl), Group B (MCJ), Group C (Aloe vera), Group D (Propolis) and Group E (Saline). These groups were treated with passive ultrasonic irrigation (PUI) along with the respective irrigants. The root halves were processed for scanning electron microscopy. Three images (X2.5), coronal, middle and apical, were taken for the twelve root halves in each of the five groups. The images were randomized and biofilm coverage assessed independently by three calibrated examiners, using a four-point scoring system. 1% NaOCl with passive ultrasonic irrigation (PUI) was effective in completely removing E. faecalis biofilm and was superior to the natural irrigants like MCJ, Aloe vera and Propolis tested in this study. 1% NaOCl used along with passive ultrasonic irrigation was effective in completely removing E. faecalis biofilm when compared to natural irrigants (MCJ, Aloe Vera and Propolis).

Dundee Canal Industrial Historic District, Beginning at George Street in ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Dundee Canal Industrial Historic District, Beginning at George Street in Passaic & extending north along Dundee Canal approximately 1.2 miles to Canal headgates opposite East Clifton Avenue in Clifton, Passaic, Passaic County, NJ

The development of recent high-power ultrasonic transducers for Near-well ultrasonic processing technology.

PubMed

Wang, Zhenjun; Xu, Yuanming

2017-07-01

With the reduction of crude oil throughout the world, enhance oil recovery technology has become a major oil research topics, which can greatly increase the recovery ratio of the crude oil before the dawning of renewable energy era. Near-well ultrasonic processing technology, as one new method, has attracted more attention for Enhanced Oil Recovery due to its low cost, good applicability and no environmental pollution in recent rears. There are two important relevant aspects about Near-well ultrasonic processing technology: (a) how to enhance the oil flow through the rocks into the pumping pool and (b) how to reduce the oil viscosity so that it can be easier to pump. Therefore, how to design a high-power ultrasonic equipment with excellent performance is crucial for Near-well ultrasonic processing technology. In this paper, recent new high-power ultrasonic transducers for Near-well ultrasonic processing technology are summarized. Each field application of them are also given. The purpose of this paper is to provide reference for the further development of Near-well ultrasonic processing technology. With the reduction of crude oil throughout the world, enhance oil recovery technology has become a major oil research topics, which can greatly increase the recovery ratio of the crude oil before the dawning of renewable energy era. Near-well ultrasonic processing technology, as one new method, has attracted more attention for Enhanced Oil Recovery due to its low cost, good applicability and no environmental pollution in recent rears. There are two important relevant aspects about Near-well ultrasonic processing technology: (a) how to enhance the oil flow through the rocks into the pumping pool and (b) how to reduce the oil viscosity so that it can be easier to pump. Therefore, how to design a high-power ultrasonic equipment with excellent performance is crucial for Near-well ultrasonic processing technology. In this paper, recent new high-power ultrasonic transducers

20. SITE BUILDING 002 SCANNER BUILDING IN COMPUTER ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

20. SITE BUILDING 002 - SCANNER BUILDING - IN COMPUTER ROOM LOOKING AT "CONSOLIDATED MAINTENANCE OPERATIONS CENTER" JOB AREA AND OPERATION WORK CENTER. TASKS INCLUDE RADAR MAINTENANCE, COMPUTER MAINTENANCE, CYBER COMPUTER MAINTENANCE AND RELATED ACTIVITIES. - Cape Cod Air Station, Technical Facility-Scanner Building & Power Plant, Massachusetts Military Reservation, Sandwich, Barnstable County, MA

C-shaped root canal in a maxillary first molar: a case report.

PubMed

Yilmaz, Z; Tuncel, B; Serper, A; Calt, S

2006-02-01

This case report presents an unusual C-shaped root canal system in a maxillary first molar tooth. Although C-shaped root canals are most frequently seen in the mandibular second molar, they may also appear in maxillary molars. A literature search revealed only a few case reports of C-shaped root canal systems in maxillary molars. The present case describes a C-shaped canal in the buccal root of a maxillary first molar. The endodontic access cavity displayed two canal orifices, one leading to the canal system in the buccal root, the other into the palatal root canal system. In the buccal root, what appeared to be the mesial and distal canals joined to form a single C-shaped canal. --Careful examination of radiographs and the internal anatomy of teeth is essential.-- The location and morphology of root canals should be identified at high magnification under the microscope.

Improved spatial resolution in PET scanners using sampling techniques

PubMed Central

Surti, Suleman; Scheuermann, Ryan; Werner, Matthew E.; Karp, Joel S.

2009-01-01

Increased focus towards improved detector spatial resolution in PET has led to the use of smaller crystals in some form of light sharing detector design. In this work we evaluate two sampling techniques that can be applied during calibrations for pixelated detector designs in order to improve the reconstructed spatial resolution. The inter-crystal positioning technique utilizes sub-sampling in the crystal flood map to better sample the Compton scatter events in the detector. The Compton scatter rejection technique, on the other hand, rejects those events that are located further from individual crystal centers in the flood map. We performed Monte Carlo simulations followed by measurements on two whole-body scanners for point source data. The simulations and measurements were performed for scanners using scintillators with Zeff ranging from 46.9 to 63 for LaBr3 and LYSO, respectively. Our results show that near the center of the scanner, inter-crystal positioning technique leads to a gain of about 0.5-mm in reconstructed spatial resolution (FWHM) for both scanner designs. In a small animal LYSO scanner the resolution improves from 1.9-mm to 1.6-mm with the inter-crystal technique. The Compton scatter rejection technique shows higher gains in spatial resolution but at the cost of reduction in scanner sensitivity. The inter-crystal positioning technique represents a modest acquisition software modification for an improvement in spatial resolution, but at a cost of potentially longer data correction and reconstruction times. The Compton scatter rejection technique, while also requiring a modest acquisition software change with no increased data correction and reconstruction times, will be useful in applications where the scanner sensitivity is very high and larger improvements in spatial resolution are desirable. PMID:19779586

Ultrasonic Determination Of Recrystallization

NASA Technical Reports Server (NTRS)

Generazio, Edward R.

1988-01-01

State of recrystallization identified. Measurement of ultrasonic attenuation shows promise as means of detecting recrystallization in metal. Technique applicable to real-time acoustic monitoring of thermomechanical treatments. Starting with work-hardened material, one ultrasonically determines effect of annealing, using correlation between ultrasonic attenuation and temperature.

The effects of different irrigation protocols on removing calcium hydroxide from the root canals.

PubMed

Üstün, Y; Aslan, T; Sagsen, B; Dincer, A N

2016-01-01

The aim of this study was to evaluate the efficiencies of different irrigation protocols and solutions in the removal of calcium hydroxide (Ca[OH]2). Sixty-eight maxillary incisors were used. Root canals were prepared and filled with Ca(OH)2. Two control (n = 4) and six experimental groups (n = 10) were adjusted: Group 1:1% peracetic acid (PAA) + master apical file (MAF); Group 2: 17% ethylenediaminetetraacetic acid (EDTA) + MAF; Group 3: 9% 1-hydroxyethylidene-1,1-bisphosphonate (HEBP) + MAF; Group 4: 1% PAA + ultrasonic activation (UA); Group 5: 17% EDTA + UA; Group 6: 9% HEBP + UA. The cleanliness of root canal thirds were evaluated with scanning electron microscopy. Statistical analysis were performed (α = 0.05). At coronal thirds; PAA + UA was superior to EDTA + MAF, HEBP + MAF; and PAA + MAF was superior to EDTA + MAF, HEBP + MAF (P < 0.05). At middle thirds; PAA + MAF and PAA + UA were superior to EDTA + MAF and EDTA + UA; and, PAA + UA was superior to HEBP + MAF (P < 0.05). There were no significant differences among the rest of the experimental groups (P > 0.05). Complete removal of Ca(OH)2could not be achieved by none of the irrigants at all root thirds.

Comparative study of ProTaper gold, reciproc, and ProTaper universal for root canal preparation in severely curved root canals

PubMed Central

Arslan, Hakan; Yildiz, Ezgi Doganay; Gunduz, Hicran Ates; Sumbullu, Meltem; Bayrakdar, Ibrahim Sevki; Karatas, Ertugrul; Sumbullu, Muhammed Akif

2017-01-01

Aim: The aim of this study is to evaluate the root canal transportation, centering ability, and instrumentation times with the ProTaper Gold (Dentsply Tulsa Dental, Tulsa, OK, USA), Reciproc (VDW, Munich, Germany), and ProTaper Universal (Dentsply Maillefer, Ballaigues, Switzerland) using cone-beam computed tomography (CBCT). Materials and Methods: Thirty mesial root canals of mandibular first molars with curvature angles of 35°–70° and radii of 2–6 mm were included in the study. Root canal instrumentation was performed up to F2 or R25. The instrumentation times were recorded. CBCT scanning was performed both pre- and post-instrumentation. Root canal transportation and the centering ratio were calculated for groups, and the data were analyzed using a one-way ANOVA and least significant difference post hoc tests for the instrumentation time, root canal transportation, and centering ratio at the 95% confidence level (P = 0.05). Results: At 3, 5, and 7 mm levels, there was no significant difference in the root canal transportation and centering ratio among the groups (P > 0.05). There were significant differences between the Reciproc and ProTaper Universal groups in the instrumentation times (P < 0.05). Conclusion: Root canal transportation and the centering ratio with the ProTaper Gold were similar to those obtained with the ProTaper Universal and Reciproc. PMID:29259355

Enhancing reproducibility of ultrasonic measurements by new users

NASA Astrophysics Data System (ADS)

Pramanik, Manojit; Gupta, Madhumita; Krishnan, Kajoli Banerjee

2013-03-01

Perception of operator influences ultrasound image acquisition and processing. Lower costs are attracting new users to medical ultrasound. Anticipating an increase in this trend, we conducted a study to quantify the variability in ultrasonic measurements made by novice users and identify methods to reduce it. We designed a protocol with four presets and trained four new users to scan and manually measure the head circumference of a fetal phantom with an ultrasound scanner. In the first phase, the users followed this protocol in seven distinct sessions. They then received feedback on the quality of the scans from an expert. In the second phase, two of the users repeated the entire protocol aided by visual cues provided to them during scanning. We performed off-line measurements on all the images using a fully automated algorithm capable of measuring the head circumference from fetal phantom images. The ground truth (198.1±1.6 mm) was based on sixteen scans and measurements made by an expert. Our analysis shows that: (1) the inter-observer variability of manual measurements was 5.5 mm, whereas the inter-observer variability of automated measurements was only 0.6 mm in the first phase (2) consistency of image appearance improved and mean manual measurements was 4-5 mm closer to the ground truth in the second phase (3) automated measurements were more precise, accurate and less sensitive to different presets compared to manual measurements in both phases. Our results show that visual aids and automation can bring more reproducibility to ultrasonic measurements made by new users.

21 CFR 892.1300 - Nuclear rectilinear scanner.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Nuclear rectilinear scanner. 892.1300 Section 892...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1300 Nuclear rectilinear scanner. (a) Identification. A nuclear rectilinear scanner is a device intended to image the distribution of radionuclides in...

21 CFR 892.1300 - Nuclear rectilinear scanner.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Nuclear rectilinear scanner. 892.1300 Section 892...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1300 Nuclear rectilinear scanner. (a) Identification. A nuclear rectilinear scanner is a device intended to image the distribution of radionuclides in...

Ultrasonic cleaning: Fundamental theory and application

NASA Technical Reports Server (NTRS)

Fuchs, F. John

1995-01-01

This presentation describes: the theory of ultrasonics, cavitation and implosion; the importance and application of ultrasonics in precision cleaning; explanations of ultrasonic cleaning equipment options and their application; process parameters for ultrasonic cleaning; and proper operation of ultrasonic cleaning equipment to achieve maximum results.

Glaser Fissure, Huguier Canal, and Civinini Canal: A Confused Eponymical Imbroglio.

PubMed

Mudry, Albert

2015-07-01

Huguier canal or Civinini canal is a canaliculus in the Glaser fissure allowing the exit of the chorda tympani from the tympanic cavity. The aim of this study is to try to put some order in the origins and relations of these different eponyms, and to evaluate their pertinence in the actual anatomical terminology. This study demonstrates that Huguier and Civinini are not the first to describe this canal in the 1830s. Furthermore, it confirms that Glaser does not describe the related fissure in 1680. In conclusion, Glaser, Civinini, and Huguier no longer have a place in the actual anatomical nomenclature of the fine details of the temporal bone. To avoid confusion and errors, they must be replaced by anterior canaliculus for the chorda tympani and petrotympanic fissure.

Occurrence and characteristics of mutual interference between LIDAR scanners

NASA Astrophysics Data System (ADS)

Kim, Gunzung; Eom, Jeongsook; Park, Seonghyeon; Park, Yongwan

2015-05-01

The LIDAR scanner is at the heart of object detection of the self-driving car. Mutual interference between LIDAR scanners has not been regarded as a problem because the percentage of vehicles equipped with LIDAR scanners was very rare. With the growing number of autonomous vehicle equipped with LIDAR scanner operated close to each other at the same time, the LIDAR scanner may receive laser pulses from other LIDAR scanners. In this paper, three types of experiments and their results are shown, according to the arrangement of two LIDAR scanners. We will show the probability that any LIDAR scanner will interfere mutually by considering spatial and temporal overlaps. It will present some typical mutual interference scenario and report an analysis of the interference mechanism.

Portable biochip scanner device

DOEpatents

Perov, Alexander; Sharonov, Alexei; Mirzabekov, Andrei D.

2002-01-01

A portable biochip scanner device used to detect and acquire fluorescence signal data from biological microchips (biochips) is provided. The portable biochip scanner device employs a laser for emitting an excitation beam. An optical fiber delivers the laser beam to a portable biochip scanner. A lens collimates the laser beam, the collimated laser beam is deflected by a dichroic mirror and focused by an objective lens onto a biochip. The fluorescence light from the biochip is collected and collimated by the objective lens. The fluorescence light is delivered to a photomultiplier tube (PMT) via an emission filter and a focusing lens. The focusing lens focuses the fluorescence light into a pinhole. A signal output of the PMT is processed and displayed.

22. TWIN FALLS MAIN CANAL HEADWORKS WITH MILNER DAM IN ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

22. TWIN FALLS MAIN CANAL HEADWORKS WITH MILNER DAM IN DISTANCE; LOOKING EAST. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

23. TWIN FALLS MAIN CANAL HEADWORKS WITH MILNER DAM IN ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

23. TWIN FALLS MAIN CANAL HEADWORKS WITH MILNER DAM IN DISTANCE; LOOKING NORTHEAST. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

The acousto-ultrasonic approach

NASA Technical Reports Server (NTRS)

Vary, Alex

1987-01-01

The nature and underlying rationale of the acousto-ultrasonic approach is reviewed, needed advanced signal analysis and evaluation methods suggested, and application potentials discussed. Acousto-ultrasonics is an NDE technique combining aspects of acoustic emission methodology with ultrasonic simulation of stress waves. This approach uses analysis of simulated stress waves for detecting and mapping variations of mechanical properties. Unlike most NDE, acousto-ultrasonics is less concerned with flaw detection than with the assessment of the collective effects of various flaws and material anomalies. Acousto-ultrasonics has been applied chiefly to laminated and filament-wound fiber reinforced composites. It has been used to assess the significant strength and toughness reducing effects that can be wrought by combinations of essentially minor flaws and diffuse flaw populations. Acousto-ultrasonics assesses integrated defect states and the resultant variations in properties such as tensile, shear, and flexural strengths and fracture resistance. Matrix cure state, porosity, fiber orientation, fiber volume fraction, fiber-matrix bonding, and interlaminar bond quality are underlying factors.

ULTRASONIC NEUTRON DOSIMETER

DOEpatents

Truell, R.; de Klerk, J.; Levy, P.W.

1960-02-23

A neutron dosimeter is described which utilizes ultrasonic waves in the megacycle region for determination of the extent of neutron damage in a borosilicate glass through ultrasonic wave velocity and attenuation measurements before and after damage.

Craniopharyngeal canal and its spectrum of pathology.

PubMed

Abele, T A; Salzman, K L; Harnsberger, H R; Glastonbury, C M

2014-04-01

The craniopharyngeal canal is a rare, well-corticated defect through the midline of the sphenoid bone from the sellar floor to the anterosuperior nasopharyngeal roof. We reviewed a series of craniopharyngeal canals to determine a system of classification that might better our understanding of this entity, highlight the range of associated pathologic conditions, and optimize patient treatment. Available MR imaging, CT, and clinical data (from 1989-2013) of 29 patients (10 female, 15 male, 4 unknown; median age, 4 years; age range, 1 day-65 years) with craniopharyngeal canals were retrospectively examined. Qualitative assessment included orthotopic or ectopic adenohypophysis and the presence of a tumor and/or cephalocele. The midpoint anteroposterior diameter was measured. Clinical and imaging data were evaluated for pituitary dysfunction and accompanying anomalies. Craniopharyngeal canals were qualitatively separated into 3 types: incidental canals (type 1); canals with ectopic adenohypophysis (type 2); and canals containing cephaloceles (type 3A), tumors (type 3B), or both (type 3C), including pituitary adenoma, craniopharyngioma, dermoid, teratoma, and glioma. Quantitative evaluation showed a significant difference (P < .0001) in the anteroposterior diameters of type 1 canals (median, 0.8; range, 0.7-1.1 mm), type 2 canals (median, 3.9, range, 3.5-4.4 mm), and type 3 canals (median, 9.0; range, 5.9-31.0 mm) imparting small, medium, and large descriptors. Canals with cephaloceles all contained an ectopic adenohypophysis. The craniopharyngeal canals were associated with pituitary dysfunction (6/29) and congenital anomalies (8/29). Accurate diagnosis and classification of craniopharyngeal canals are valuable to characterize lesions requiring surgery, identify patients with potential pituitary dysfunction, and avoid iatrogenic hypopituitarism or CSF leak during surgical resection of nasopharyngeal masses.

Oceanographic scanner system design study, volume 1

NASA Technical Reports Server (NTRS)

1971-01-01

The design is reported of a dual mode multispectral scanner, capable of satisfying both overland and oceanographic requirements. A complete system description and performance summary of the scanner are given. In addition, subsystem and component descriptions and performance analyses are treated in individual sections. The design of the scanner, with minimum modifications, interfaces to the ERTS spacecraft and the ground data handling system.

Recent progress in online ultrasonic process monitoring

NASA Astrophysics Data System (ADS)

Wen, Szu-Sheng L.; Chen, Tzu-Fang; Ramos-Franca, Demartonne; Nguyen, Ky T.; Jen, Cheng-Kuei; Ihara, Ikuo; Derdouri, A.; Garcia-Rejon, Andres

1998-03-01

On-line ultrasonic monitoring of polymer co-extrusion and gas-assisted injection molding are presented. During the co- extrusion of high density polyethylene and Santoprene ultrasonic sensors consisting of piezoelectric transducers and clad ultrasonic buffer rods are used to detect the interface between these two polymers and the stability of the extrusion. The same ultrasonic sensor also measures the surface temperature of the extruded polymer. The results indicate that temperature measurements using ultrasound have a faster response time than those obtained by conventional thermocouple. In gas-assisted injection molding the polymer and gas flow front positions are monitored simultaneously. This information may be used to control the plunger movement.

47. FEEDER CANAL AT WILL'S BASIN. BOATS IN THE FOREGROUND ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

47. FEEDER CANAL AT WILL'S BASIN. BOATS IN THE FOREGROUND SHOW THE CONTRAST BETWEEN A FULLY LOADED CANAL BOAT (LEFT) AND AN EMPTY ONE (RIGHT). D, L & W RAILROAD'S DOUBLE INTERSECTION PRATT TRUSS BRIDGE IS VISIBLE IN BACKGROUND. - Morris Canal, Phillipsburg, Warren County, NJ

Distributed control at Love canal

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

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.

13. VIEW OF WESTERN CANAL EAST OF CARRIAGE LANE IN ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

13. VIEW OF WESTERN CANAL EAST OF CARRIAGE LANE IN TEMPE, SHOWING DROP STRUCTURE AND GROUNDWATER PUMP. THIS IS THE LAST OF FOUR PUMPS WHICH FEED DIRECTLY INTO THE CANAL BETWEEN ALMA SCHOOL ROAD AND PRICE ROAD. ON THIS DAY, ALL FOUR PUMPS, OPERATING AT FULL OUTPUT, HAVE CONSIDERABLY SWELLED THE FLOW TO THE CANAL. NOTE THE OLD FASHIONED BRICKWORK ON THE NORTH BANK. - Western Canal, South side of Salt River between Tempe, Phoenix & Mesa, Mesa, Maricopa County, AZ

70. GENERAL VIEW OF CANAL IN DOVER LOOKING EAST. WHAT ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

70. GENERAL VIEW OF CANAL IN DOVER LOOKING EAST. WHAT APPEARS TO BE A SWING BRIDGE IS VISIBLE ACROSS CANAL ON RIGHT SIDE OF PHOTOGRAPH (NOTE THAT THIS MAY ALSO BE A LIFT BRIDGE WITH THE LIFT EQUIPMENT REMOVED). - Morris Canal, Phillipsburg, Warren County, NJ

Dorello's Canal for Laymen: A Lego-Like Presentation.

PubMed

Ezer, Haim; Banerjee, Anirban Deep; Thakur, Jai Deep; Nanda, Anil

2012-06-01

Objective Dorello's canal was first described by Gruber in 1859, and later by Dorello. Vail also described the anatomy of Dorello's canal. In the preceding century, Dorello's canal was clinically important, in understanding sixth nerve palsy and nowadays it is mostly important for skull base surgery. The understanding of the three dimensional anatomy, of this canal is very difficult to understand, and there is no simple explanation for its anatomy and its relationship with adjacent structures. We present a simple, Lego-like, presentation of Dorello's canal, in a stepwise manner. Materials and Methods Dorello's canal was dissected in five formalin-fixed cadaver specimens (10 sides). The craniotomy was performed, while preserving the neural and vascular structures associated with the canal. A 3D model was created, to explain the canal's anatomy. Results Using the petrous pyramid, the sixth nerve, the cavernous sinus, the trigeminal ganglion, the petorclival ligament and the posterior clinoid, the three-dimensional structure of Dorello's canal was defined. This simple representation aids in understanding the three dimensional relationship of Dorello's canal to its neighboring structures. Conclusion Dorello's canal with its three dimensional structure and relationship to its neighboring anatomical structures could be reconstructed using a few anatomical building blocks. This method simplifies the understanding of this complex anatomical structure, and could be used for teaching purposes for aspiring neurosurgeons, and anatomy students.

Dorello's Canal for Laymen: A Lego-Like Presentation

PubMed Central

Ezer, Haim; Banerjee, Anirban Deep; Thakur, Jai Deep; Nanda, Anil

2012-01-01

Objective Dorello's canal was first described by Gruber in 1859, and later by Dorello. Vail also described the anatomy of Dorello's canal. In the preceding century, Dorello's canal was clinically important, in understanding sixth nerve palsy and nowadays it is mostly important for skull base surgery. The understanding of the three dimensional anatomy, of this canal is very difficult to understand, and there is no simple explanation for its anatomy and its relationship with adjacent structures. We present a simple, Lego-like, presentation of Dorello's canal, in a stepwise manner. Materials and Methods Dorello's canal was dissected in five formalin-fixed cadaver specimens (10 sides). The craniotomy was performed, while preserving the neural and vascular structures associated with the canal. A 3D model was created, to explain the canal's anatomy. Results Using the petrous pyramid, the sixth nerve, the cavernous sinus, the trigeminal ganglion, the petorclival ligament and the posterior clinoid, the three-dimensional structure of Dorello's canal was defined. This simple representation aids in understanding the three dimensional relationship of Dorello's canal to its neighboring structures. Conclusion Dorello's canal with its three dimensional structure and relationship to its neighboring anatomical structures could be reconstructed using a few anatomical building blocks. This method simplifies the understanding of this complex anatomical structure, and could be used for teaching purposes for aspiring neurosurgeons, and anatomy students. PMID:23730547

Morphometric study of the lumbar spinal canal in the Korean population.

PubMed

Lee, H M; Kim, N H; Kim, H J; Chung, I H

1995-08-01

The anatomic dimensions of the vertebral body and spinal canal of the lumbar spine were analyzed in Koreans. To determine the normal dimension of the lumbar spinal canal in Koreans, to determine whether there are any racial differences in the morphometry of the lumbar spinal canal, and to provide criteria for diagnosing spinal stenosis in the Far Eastern Asian. Some radiologic and anatomic studies have been conducted regarding the size of the lumbar spinal canal of whites and blacks in western and African countries. One-thousand-eight-hundred measurements were performed on the transverse and sagittal diameters of vertebral bodies and spinal canals using complete sets of 90 lumbar vertebrae. The mean mid-sagittal diameter of the lumbar spinal canal in the Korean population was less than that measured in white and African populations, but there was no significant differences between the Korean, white, and African populations regarding the transverse diameter of the lumbar spinal canal. The mid-sagittal diameter of the lumbar spinal canal is narrowest in the Far Eastern Asian population; the radiologic criteria of spinal stenosis should be reconsidered for these people.

Ultrasonic Polishing

NASA Technical Reports Server (NTRS)

Gilmore, Randy

1993-01-01

The ultrasonic polishing process makes use of the high-frequency (ultrasonic) vibrations of an abradable tool which automatically conforms to the work piece and an abrasive slurry to finish surfaces and edges on complex, highly detailed, close tolerance cavities in materials from beryllium copper to carbide. Applications range from critical deburring of guidance system components to removing EDM recast layers from aircraft engine components to polishing molds for forming carbide cutting tool inserts or injection molding plastics. A variety of materials including tool steels, carbides, and even ceramics can be successfully processed. Since the abradable tool automatically conforms to the work piece geometry, the ultrasonic finishing method described offers a number of important benefits in finishing components with complex geometries.

Artificial Intelligence Assists Ultrasonic Inspection

NASA Technical Reports Server (NTRS)

Schaefer, Lloyd A.; Willenberg, James D.

1992-01-01

Subtle indications of flaws extracted from ultrasonic waveforms. Ultrasonic-inspection system uses artificial intelligence to help in identification of hidden flaws in electron-beam-welded castings. System involves application of flaw-classification logic to analysis of ultrasonic waveforms.

Ultrasonic Imaging System

NASA Technical Reports Server (NTRS)

Youngquist, Robert C. (Inventor); Moerk, Steven (Inventor)

1999-01-01

An imaging system is described which can be used to either passively search for sources of ultrasonics or as an active phase imaging system. which can image fires. gas leaks, or air temperature gradients. This system uses an array of ultrasonic receivers coupled to an ultrasound collector or lens to provide an electronic image of the ultrasound intensity in a selected angular region of space. A system is described which includes a video camera to provide a visual reference to a region being examined for ultrasonic signals.

Root canal preparation in endodontics: conventional versus laser methods

NASA Astrophysics Data System (ADS)

Goodis, Harold E.; White, Joel M.; Marshall, Sally J.; Marshall, Grayson W.; Moskowitz, Emrey

1992-06-01

Conventional cleaning and shaping of root canal systems employs hand and/or rotary instrumentation to remove the contents of the canal and shape the canal to receive a filling material. With the advent of the Nd:YAG laser system another method of accomplishing proper cleaning and shaping is evaluated. Single rooted teeth were radiographed bucco- lingually and mesio-distally and were divided into 2 groups. The first group was accessed and the root canal systems cleaned and shaped with a step back technique utilizing hand files and gates glidden burs. At completion of the procedure the teeth were again radiographed at the same positions as those prior to the procedure. The teeth were split longitudinally and examined under scanning electron microscopy to assess cleaning. The second group of teeth were accessed, and cleaning and shaping was accomplished using the Nd:YAG laser in combination with hand files and rotary instruments. These teeth were subjected to the same analysis as those in the first group. The before and after radiographs of each group were subjected to image analysis to determine effectiveness of the two methods in shaping the canal systems. We will discuss the ability of Nd:YAG to clean and shape root canal spaces and remove smear layer and organic tissue remnants from those areas.

An RF dosimeter for independent SAR measurement in MRI scanners

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qian, Di; Bottomley, Paul A.; El-Sharkawy, AbdEl-Monem M.

2013-12-15

Purpose: The monitoring and management of radio frequency (RF) exposure is critical for ensuring magnetic resonance imaging (MRI) safety. Commercial MRI scanners can overestimate specific absorption rates (SAR) and improperly restrict clinical MRI scans or the application of new MRI sequences, while underestimation of SAR can lead to tissue heating and thermal injury. Accurate scanner-independent RF dosimetry is essential for measuring actual exposure when SAR is critical for ensuring regulatory compliance and MRI safety, for establishing RF exposure while evaluating interventional leads and devices, and for routine MRI quality assessment by medical physicists. However, at present there are no scanner-independentmore » SAR dosimeters. Methods: An SAR dosimeter with an RF transducer comprises two orthogonal, rectangular copper loops and a spherical MRI phantom. The transducer is placed in the magnet bore and calibrated to approximate the resistive loading of the scanner's whole-body birdcage RF coil for human subjects in Philips, GE and Siemens 3 tesla (3T) MRI scanners. The transducer loop reactances are adjusted to minimize interference with the transmit RF field (B{sub 1}) at the MRI frequency. Power from the RF transducer is sampled with a high dynamic range power monitor and recorded on a computer. The deposited power is calibrated and tested on eight different MRI scanners. Whole-body absorbed power vs weight and body mass index (BMI) is measured directly on 26 subjects. Results: A single linear calibration curve sufficed for RF dosimetry at 127.8 MHz on three different Philips and three GE 3T MRI scanners. An RF dosimeter operating at 123.2 MHz on two Siemens 3T scanners required a separate transducer and a slightly different calibration curve. Measurement accuracy was ∼3%. With the torso landmarked at the xiphoid, human adult whole‑body absorbed power varied approximately linearly with patient weight and BMI. This indicates that whole-body torso SAR is

Application of software for automated canal management (SacMan) to the WM lateral canal

USDA-ARS?s Scientific Manuscript database

Simulation studies have demonstrated that automatic control of canals is more effective when feedforward scheduling, or routing of know demand changes, is combined with centralized, automatic, distant, downstream-water-level control. In practice, few canals use this approach. To help further develop...

Ultrasonic wave propagation in powders

NASA Astrophysics Data System (ADS)

Al-Lashi, R. S.; Povey, M. J. W.; Watson, N. J.

2018-05-01

Powder clumps (cakes) has a significant effect on the flowability and stability of powders. Powder caking is mainly caused by moisture migration due to wetting and environmental (temperature and humidity) changes. The process of moisture migration caking involves creating liquid bridges between the particles during condensation which subsequently harden to form solid bridges. Therefore, an effective and reliable technique is required to quantitatively and non-invasively monitor caking kinetics and effective stiffness. This paper describes two ultrasonic instruments (ultrasonic velocity pulse and airborne ultrasound systems) that have been used to monitor the caking phenomenon. Also, it discusses the relationship between the ultrasonic velocity and attenuation measurements and tracking caking kinetics and the effective stiffness of powders.

12. VIEW OF WESTERN CANAL AT ALMA SCHOOL ROAD IN ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

12. VIEW OF WESTERN CANAL AT ALMA SCHOOL ROAD IN MESA, THE LOCATION AT WHICH THE PECK, PINE AND WALLACE FEEDERS FORMERLY JOINED TO FORM THE WESTERN CANAL. THE PECK AND PINE FEEDERS, NOW KNOWN AS LATERAL 9 AND LATERAL 10, AND ALMOST ENTIRELY PIPED, STILL JOIN THE WESTERN CANAL AT THIS POINT, BUT AN EQUALLY IMPORTANT SOURCE OF SUPPLY IS THE NUMEROUS GROUNDWATER PUMPS LOCATED ON THE SYSTEM. - Western Canal, South side of Salt River between Tempe, Phoenix & Mesa, Mesa, Maricopa County, AZ

Spectral characterization of the LANDSAT-D multispectral scanner subsystems

NASA Technical Reports Server (NTRS)

Markham, B. L. (Principal Investigator); Barker, J. L.

1982-01-01

Relative spectral response data for the multispectral scanner subsystems (MSS) to be flown on LANDSAT-D and LANDSAT-D backup, the protoflight and flight models, respectively, are presented and compared to similar data for the Landsat 1,2, and 3 subsystems. Channel-bychannel (six channels per band) outputs for soil and soybean targets were simulated and compared within each band and between scanners. The two LANDSAT-D scanners proved to be nearly identical in mean spectral response, but they exhibited some differences from the previous MSS's. Principal differences between the spectral responses of the D-scanners and previous scanners were: (1) a mean upper-band edge in the green band of 606 nm compared to previous means of 593 to 598 nm; (2) an average upper-band edge of 697 nm in the red band compared to previous averages of 701 to 710 nm; and (3) an average bandpass for the first near-IR band of 702-814 nm compared to a range of 693-793 to 697-802 nm for previous scanners. These differences caused the simulated D-scanner outputs to be 3 to 10 percent lower in the red band and 3 to 11 percent higher in the first near-IR band than previous scanners for the soybeans target. Otherwise, outputs from soil and soybean targets were only slightly affected. The D-scanners were generally more uniform from channel to channel within bands than previous scanners.

Discharge rate measurements in a canal using radiotracer methods.

PubMed

Pant, H J; Goswami, Sunil; Biswal, Jayashree; Samantray, J S; Sharma, V K

2016-06-01

Discharge rates of water were measured in a canal using radiotracer methods with an objective to validate the efficacy of Concrete Volute Pumps (CVPs) installed at various pumping stations along the canal. Pulse velocity and dilution methods were applied to measure the discharge rates using Iodine-131 as a radiotracer. The discharge rate measured in one of the sections of the canal using the pulse velocity method was found to be 22.5m(3)/s, whereas the discharge rates measured using the dilution method in four different sections of the canal varied from 20.27 to 20.62m(3)/s with single CVP in operation. The standard error in discharge rate measurements using dilution method ranged from ±1.1 to ±1.8%. The experimentally measured values of the discharge rate were in good agreement with the design value of the discharge rate (20m(3)/s) thus validating the performance of the CVPs used in the canal. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ultrasonic imaging system for in-process fabric defect detection

DOEpatents

Sheen, Shuh-Haw; Chien, Hual-Te; Lawrence, William P.; Raptis, Apostolos C.

1997-01-01

An ultrasonic method and system are provided for monitoring a fabric to identify a defect. A plurality of ultrasonic transmitters generate ultrasonic waves relative to the fabric. An ultrasonic receiver means responsive to the generated ultrasonic waves from the transmitters receives ultrasonic waves coupled through the fabric and generates a signal. An integrated peak value of the generated signal is applied to a digital signal processor and is digitized. The digitized signal is processed to identify a defect in the fabric. The digitized signal processing includes a median value filtering step to filter out high frequency noise. Then a mean value and standard deviation of the median value filtered signal is calculated. The calculated mean value and standard deviation are compared with predetermined threshold values to identify a defect in the fabric.

Overview of the ultrasonic instrumentation research in the MYRRHA project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dierckx, M.; Leysen, W.; Van Dyck, D.

The Belgian Nuclear Research Centre SCK.CEN is in the process of developing MYRRHA, a new generation IV fast flux research reactor to replace the aging BR2. MYRRHA is conceptualized as an accelerator driven system cooled with lead bismuth eutectic mixture (LBE). As LBE is opaque to visual light, ultrasonic measurement techniques are employed as the main technology to provide feedback where needed. This paper we will give an overview of the R and D at SCK.CEN with respect to ultrasonic instrumentation in heavy liquid metals. High temperature ultrasonic transducers are deployed into the reactor to generate and receive the requiredmore » ultrasonic signals. The ultrasonic waves are generated and sensed by means of a piezo-electric disc at the heart of the transducer. The acoustic properties of commonly used piezo-electric materials match rather well with the acoustic properties of heavy liquid metals, simplifying the design and construction of high bandwidth ultrasonic transducers for use in heavy liquid metals. The ultrasonic transducers will operate in a liquid metal environment, where radiation and high temperature limit the choice of materials for construction. Moreover, the high surface tension of the liquid metal hinders proper wetting of the transducer, required for optimal transmission and reception of the ultrasonic waves. In a first part of the paper, we will discuss the effect of these parameters on the performance of the overall ultrasonic system. In the second part of the paper, past, present and future ultrasonic experiments in LBE will be reviewed. We will show the results of an experiment where a transducer is scanned near the free surface of an LBE pool to render ultrasonic images of objects submerged in the heavy liquid metal. Additionally, the preliminary results of an ongoing experiment that measures the evolution of LBE wetting on different types of metals and various surface conditions will be reported. The evolution of wetting is an important

Comparison among manual instruments and PathFile and Mtwo rotary instruments to create a glide path in the root canal preparation of curved canals.

PubMed

Alves, Vanessa de Oliveira; Bueno, Carlos Eduardo da Silveira; Cunha, Rodrigo Sanches; Pinheiro, Sérgio Luiz; Fontana, Carlos Eduardo; de Martin, Alexandre Sigrist

2012-01-01

Nickel-titanium rotary instruments reduce procedural errors and the time required to finish root canal preparation. The goal of this study was to evaluate the occurrences of apical transportation and canal aberrations produced with different instruments used to create a glide path in the preparation of curved root canals, namely manual K-files (Dentsply Maillefer, Ballaigues, Switzerland) and PathFile (Dentsply Maillefer) and Mtwo (Sweden and Martina, Padua, Italy) nickel-titanium rotary files. The mesial canals of 45 mandibular first and second molars (with curvature angles between 25° and 35°) were selected for this study. The specimens were divided randomly into 3 groups with 15 canals each, and canal preparation was performed by an endodontist using #10-15-20 K-type stainless steel manual files (group M), #13-16-19 PathFile rotary instruments (group PF), and #10-15-20 Mtwo rotary instruments (group MT). The double digital radiograph technique was used, pre- and postinstrumentation, to assess whether apical transportation and/or aberration in root canal morphology occurred. The initial and final images of the central axis of the canals were compared by superimposition through computerized analysis and with the aid of magnification. The specimens were analyzed by 3 evaluators, whose calibration was checked using the Kendall agreement test. No apical transportation or aberration in root canal morphology occurred in any of the teeth; therefore, no statistical analysis was conducted. Neither the manual instruments nor the PathFile or Mtwo rotary instruments used to create a glide path had any influence on the occurrence of apical transportation or produced any canal aberration. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

The Semicircular Canal Microphonic

NASA Technical Reports Server (NTRS)

Rabbitt, R. D.; Boyle, R.; Highstein, S. M.; Dalton, Bonnie P. (Technical Monitor)

2002-01-01

Present experiments were designed to quantify the alternating current (AC) component of the semicircular canal microphonic for angular motion stimulation as a function of stimulus frequency and amplitude. The oyster toadfish, Opsanus tau, was used as the experimental model. Calibrated mechanical indentation of the horizontal canal duct was used as a stimulus to generate hair-cell and afferent responses reproducing those present during head rotation. Sensitivity to polarization of the endolymph DC voltage re: perilymph was also investigated. Modulation of endolymph voltage was recorded using conventional glass electrodes and lock-in amplification over the frequency range 0.2-80 Hz. Access to the endolymph for inserting voltage recording and current passing electrodes was obtained by sectioning the anterior canal at its apex and isolating the cut ends in air. For sinusoidal stimulation below approx.10 Hz, the horizontal semicircular canal AC microphonic was nearly independent of stimulus frequency and equal to approximately 4 microV per micron indent (equivalent to approx. 1 microV per deg/s). A saturating nonlinearity decreasing the microphonic gain was present for stimuli exceeding approx.3 micron indent (approx. 12 deg/s angular velocity). The phase was not sensitive to the saturating nonlinearity. The microphonic exhibited a resonance near 30Hz consistent with basolateral current hair cell resonance observed previously in voltage-clamp records from semicircular canal hair cells. The magnitude and phase of the microphonic exhibited sensitivity to endolymphatic polarization consistent with electro-chemical reversal of hair cell transduction currents.

Water Environment Evolution along the China Grand Canal

NASA Astrophysics Data System (ADS)

Mao, F.; Wu, Y. X.; Yang, B. F.; Li, X. J.

2014-03-01

The China Grand Canal is one of the earliest canals in the world, having lasted for nearly 3000 years. Even its section canals have a rich history, such as the North-South Grand Canal that was established during the Sui Dynasty, whereas the Beijing-Hangzhou Canal was excavated during the Yuan Dynasty and the east line of the South-to-North Water Diversion. As one of the longest in the world, the China Grand Canal's total length is over 3500 kilometers. This length includes the navigable, unnavigable, and underground sections. Making the best use of situations and according to local conditions, the Chinese people harmoniously constructed the Beijing-Hangzhou Canal with nature. Tens of millions of workers took nearly 3000 years to complete the great shipping system. Navigable sections still exist for up to 900 kilometers and the volume of freight traffic is approximately 300 million tons. The canal remains the main logistical channel of the North-to-South Coal Transportation, South-to-North Water Diversion, and resources circulation. To date, China is promoting the success of heritage application. Part of these efforts is the declaration of the China Grand Canal as a World Cultural Heritage by 2014. In addition, the east route of the South-to-North Water Transfer project is planned to be navigable by 2016. The ancient Beijing-Hangzhou Grand Canal will usher in the new ecological civilization and cultural revival along the canal. This paper presents technical methods of water environment evolution research on the river system, river, and water quality along the Beijing-Hangzhou Canal through the integration of historical literature and modern remote sensing image data. The study carried out water environment investigation and analysis along the Beijing-Hangzhou canal by using ETM, SPOT image data, and GPS measurement data. Spatial and temporal evolution characteristics and regulations of the Beijing-Hangzhou Grand Canal regional water environment in the span of 3000

Study of Mastoid Canals and Grooves in North Karnataka Human Skulls

PubMed Central

Hadimani, Gavishiddappa Andanappa; Bagoji, Ishwar Basavantappa

2013-01-01

Introduction: This study was undertaken to observe the frequency of mastoid canals and grooves in north Karnataka dry human skulls. 100 dry human skulls of unknown age and sex from the department of Anatomy were selected and observed for the present study. Material and Methods: The mastoid regions of dry skulls were observed for the presence of mastoid canals and grooves, if any. A metallic wire was passed through the canal for its confirmation and then the length was measured. Results: The Mastoid canals were present in 53% of the total 100 skulls observed either bilaterally or unilaterally. Mastoid grooves were present in 18% of the total skulls (100) observed. Double mastoid canal was found in 01% of total skull studied and both Mastoid canals & Mastoid grooves together were present in 02% of the total skulls (100) observed. Conclusion: The knowledge of mastoid canals and grooves is very important for otolaryngologists and neurosurgeons. Because they contain an arterial branch of occipital artery with its accompanying vein which is liable to injury resulting into severe bleeding. PMID:24086832

Study of mastoid canals and grooves in north karnataka human skulls.

PubMed

Hadimani, Gavishiddappa Andanappa; Bagoji, Ishwar Basavantappa

2013-08-01

This study was undertaken to observe the frequency of mastoid canals and grooves in north Karnataka dry human skulls. 100 dry human skulls of unknown age and sex from the department of Anatomy were selected and observed for the present study. The mastoid regions of dry skulls were observed for the presence of mastoid canals and grooves, if any. A metallic wire was passed through the canal for its confirmation and then the length was measured. The Mastoid canals were present in 53% of the total 100 skulls observed either bilaterally or unilaterally. Mastoid grooves were present in 18% of the total skulls (100) observed. Double mastoid canal was found in 01% of total skull studied and both Mastoid canals & Mastoid grooves together were present in 02% of the total skulls (100) observed. The knowledge of mastoid canals and grooves is very important for otolaryngologists and neurosurgeons. Because they contain an arterial branch of occipital artery with its accompanying vein which is liable to injury resulting into severe bleeding.

Multispectral Scanner for Monitoring Plants

NASA Technical Reports Server (NTRS)

Gat, Nahum

2004-01-01

A multispectral scanner has been adapted to capture spectral images of living plants under various types of illumination for purposes of monitoring the health of, or monitoring the transfer of genes into, the plants. In a health-monitoring application, the plants are illuminated with full-spectrum visible and near infrared light and the scanner is used to acquire a reflected-light spectral signature known to be indicative of the health of the plants. In a gene-transfer- monitoring application, the plants are illuminated with blue or ultraviolet light and the scanner is used to capture fluorescence images from a green fluorescent protein (GFP) that is expressed as result of the gene transfer. The choice of wavelength of the illumination and the wavelength of the fluorescence to be monitored depends on the specific GFP.

Automated extraction method for the center line of spinal canal and its application to the spinal curvature quantification in torso X-ray CT images

NASA Astrophysics Data System (ADS)

Hayashi, Tatsuro; Zhou, Xiangrong; Chen, Huayue; Hara, Takeshi; Miyamoto, Kei; Kobayashi, Tatsunori; Yokoyama, Ryujiro; Kanematsu, Masayuki; Hoshi, Hiroaki; Fujita, Hiroshi

2010-03-01

X-ray CT images have been widely used in clinical routine in recent years. CT images scanned by a modern CT scanner can show the details of various organs and tissues. This means various organs and tissues can be simultaneously interpreted on CT images. However, CT image interpretation requires a lot of time and energy. Therefore, support for interpreting CT images based on image-processing techniques is expected. The interpretation of the spinal curvature is important for clinicians because spinal curvature is associated with various spinal disorders. We propose a quantification scheme of the spinal curvature based on the center line of spinal canal on CT images. The proposed scheme consists of four steps: (1) Automated extraction of the skeletal region based on CT number thresholding. (2) Automated extraction of the center line of spinal canal. (3) Generation of the median plane image of spine, which is reformatted based on the spinal canal. (4) Quantification of the spinal curvature. The proposed scheme was applied to 10 cases, and compared with the Cobb angle that is commonly used by clinicians. We found that a high-correlation (for the 95% confidence interval, lumbar lordosis: 0.81-0.99) between values obtained by the proposed (vector) method and Cobb angle. Also, the proposed method can provide the reproducible result (inter- and intra-observer variability: within 2°). These experimental results suggested a possibility that the proposed method was efficient for quantifying the spinal curvature on CT images.

Mandibular incisive canal: cone beam computed tomography.

PubMed

Pires, Carlos A; Bissada, Nabil F; Becker, Jeffery J; Kanawati, Ali; Landers, Michael A

2012-03-01

Panoramic radiography is often used to analyze the anatomical structure of the teeth, jaws, and temporomandibular joints. Cone beam computed tomography (CBCT) imaging allows multiple axial slices of the image to be obtained through these anatomical structures. The aim of this study was to assess CBCT compared with panoramic radiography to verify the presence, location, and dimensions of the mandibular incisive canal. CBCT scan images and panoramic radiographs of 89 subjects were compared for the presence of the mandibular incisive canal, its location, size, and anterior-posterior length. The distance between the incisive canal and the buccal and lingual plate of the alveolar bone, and the distance from the canal to the inferior border of the mandible and the tooth apex were also measured. A paired t-test was used to calculate any significant difference between the two imaging techniques. Eighty-three percent of the CBCT scans showed the presence of the incisive canal, as did 11% of the panoramic radiographs. The range of the incisive canal diameter, as seen in the CBCT scans, was from 0.4 × 0.4 mm to 4.6 × 3.2 mm. The mean length of the canal was 7 ± 3.8 mm. The distance from the inferior border of the mandible to the canal was 10.2 ± 2.4 mm, and the mean distance to the buccal plate was 2.4 mm. The apex-canal distance (in dentate subjects) was 5.3 mm. The presence, location, and dimensions of the mandibular incisive canal are better determined by CBCT imaging than by panoramic radiography. © 2009 Wiley Periodicals, Inc.

The feasibility of a scanner-independent technique to estimate organ dose from MDCT scans: Using CTDI{sub vol} to account for differences between scanners

DOE Office of Scientific and Technical Information (OSTI.GOV)

Turner, Adam C.; Zankl, Maria; DeMarco, John J.

2010-04-15

Purpose: Monte Carlo radiation transport techniques have made it possible to accurately estimate the radiation dose to radiosensitive organs in patient models from scans performed with modern multidetector row computed tomography (MDCT) scanners. However, there is considerable variation in organ doses across scanners, even when similar acquisition conditions are used. The purpose of this study was to investigate the feasibility of a technique to estimate organ doses that would be scanner independent. This was accomplished by assessing the ability of CTDI{sub vol} measurements to account for differences in MDCT scanners that lead to organ dose differences. Methods: Monte Carlo simulationsmore » of 64-slice MDCT scanners from each of the four major manufacturers were performed. An adult female patient model from the GSF family of voxelized phantoms was used in which all ICRP Publication 103 radiosensitive organs were identified. A 120 kVp, full-body helical scan with a pitch of 1 was simulated for each scanner using similar scan protocols across scanners. From each simulated scan, the radiation dose to each organ was obtained on a per mA s basis (mGy/mA s). In addition, CTDI{sub vol} values were obtained from each scanner for the selected scan parameters. Then, to demonstrate the feasibility of generating organ dose estimates from scanner-independent coefficients, the simulated organ dose values resulting from each scanner were normalized by the CTDI{sub vol} value for those acquisition conditions. Results: CTDI{sub vol} values across scanners showed considerable variation as the coefficient of variation (CoV) across scanners was 34.1%. The simulated patient scans also demonstrated considerable differences in organ dose values, which varied by up to a factor of approximately 2 between some of the scanners. The CoV across scanners for the simulated organ doses ranged from 26.7% (for the adrenals) to 37.7% (for the thyroid), with a mean CoV of 31.5% across all organs

Remote consulting based on ultrasonic digital immages and dynamic ultrasonic sequences

NASA Astrophysics Data System (ADS)

Margan, Anamarija; Rustemović, Nadan

2006-03-01

Telematic ultrasonic diagnostics is a relatively new tool in providing health care to patients in remote, islolated communities. Our project facility, "The Virtual Polyclinic - A Specialists' Consulting Network for the Islands", is located on the island of Cres in the Adriatic Sea in Croatia and has been extending telemedical services to the archipelago population since 2000. Telemedicine applications include consulting services by specialists at the University Clinical Hospital Center Rebro in Zagreb and at "Magdalena", a leading cardiology clinic in Croatia. After several years of experience with static high resolution ultrasonic digital immages for referral consulting diagnostics purposes, we now also use dynamic ultrasonic sequences in a project with the Department of Emmergency Gastroenterology at Rebro in Zagreb. The aim of the ongoing project is to compare the advantages and shortcomings in transmitting static ultrasonic digital immages and live sequences of ultrasonic examination in telematic diagnostics. Ultrasonic examination is a dynamic process in which the diagnostic accuracy is highly dependent on the dynamic moment of an ultrasound probe and signal. Our first results indicate that in diffuse parenchymal organ pathology the progression and the follow up of a disease is better presented to a remote consulting specialist by dynamic ultrasound sequences. However, the changes that involve only one part of a parenchymal organ can be suitably presented by static ultrasonic digital images alone. Furthermore, we need less time for digital imaging and such tele-consultations overall are more economical. Our previous telemedicine research and practice proved that we can greatly improve the level of medical care in remote healthcare facilities and cut healthcare costs considerably. The experience in the ongoing project points to a conclusion that we can further optimize remote diagnostics benefits by a right choice of telematic application thus reaching a

Multispectral scanner system for ERTS: Four-band scanner system. Volume 1: System description and performance

NASA Technical Reports Server (NTRS)

Norwood, V. T.; Fermelia, L. R.; Tadler, G. A.

1972-01-01

The four-band Multispectral Scanner System (MSS) is discussed. Included is a description of the MSS with major emphasis on the flight subsystem (scanner and multiplexer), the theory for the MSS calibration system processing techniques, system calibration data, and a summary of the performance of the two four-band MSS systems.

Acceleration induced water removal from ear canals.

NASA Astrophysics Data System (ADS)

Kang, Hosung; Averett, Katelee; Jung, Sunghwan

2017-11-01

Children and adults commonly experience having water trapped in the ear canals after swimming. To remove the water, individuals will shake their head sideways. Since a child's ear canal has a smaller diameter, it requires more acceleration of the head to remove the trapped water. In this study, we theoretically and experimentally investigated the acceleration required to break the surface meniscus of the water in artificial ear canals and hydrophobic-coated glass tubes. In experiments, ear canal models were 3D-printed from a CT-scanned human head. Also, glass tubes were coated with silane to match the hydrophobicity in ear canals. Then, using a linear stage, we measured the acceleration values required to forcefully eject the water from the artificial ear canals and glass tubes. A theoretical model was developed to predict the critical acceleration at a given tube diameter and water volume by using a modified Rayleigh-Taylor instability. Furthermore, this research can shed light on the potential of long-term brain injury and damage by shaking the head to push the water out of the ear canal. This research was supported by National Science Foundation Grant CBET-1604424.

Method and means of transmitting and receiving broad-band unipolar, ultrasonic pulses for ultrasonic inspection

DOEpatents

Thompson, Donald O.; Hsu, David K.

1993-12-14

The invention includes a means and method for transmitting and receiving broadband, unipolar, ultrasonic pulses for ultrasonic inspection. The method comprises generating a generally unipolar ultrasonic stress pulse from a low impedance voltage pulse transmitter along a low impedance electrical pathway to an ultrasonic transducer, and receiving the reflected echo of the pulse by the transducer, converting it to a voltage signal, and passing it through a high impedance electrical pathway to an output. The means utilizes electrical components according to the method. The means and method allow a single transducer to be used in a pulse/echo mode, and facilitates alternatingly transmitting and receiving the broadband, unipolar, ultrasonic pulses.

Ultrasonic wave based pressure measurement in small diameter pipeline.

PubMed

Wang, Dan; Song, Zhengxiang; Wu, Yuan; Jiang, Yuan

2015-12-01

An effective non-intrusive method of ultrasound-based technique that allows monitoring liquid pressure in small diameter pipeline (less than 10mm) is presented in this paper. Ultrasonic wave could penetrate medium, through the acquisition of representative information from the echoes, properties of medium can be reflected. This pressure measurement is difficult due to that echoes' information is not easy to obtain in small diameter pipeline. The proposed method is a study on pipeline with Kneser liquid and is based on the principle that the transmission speed of ultrasonic wave in pipeline liquid correlates with liquid pressure and transmission speed of ultrasonic wave in pipeline liquid is reflected through ultrasonic propagation time providing that acoustic distance is fixed. Therefore, variation of ultrasonic propagation time can reflect variation of pressure in pipeline. Ultrasonic propagation time is obtained by electric processing approach and is accurately measured to nanosecond through high resolution time measurement module. We used ultrasonic propagation time difference to reflect actual pressure in this paper to reduce the environmental influences. The corresponding pressure values are finally obtained by acquiring the relationship between variation of ultrasonic propagation time difference and pressure with the use of neural network analysis method, the results show that this method is accurate and can be used in practice. Copyright © 2015 Elsevier B.V. All rights reserved.

Patterns of directional asymmetry in the pelvis and pelvic canal.

PubMed

Tobolsky, Victoria A; Kurki, Helen K; Stock, Jay T

2016-11-01

The human pelvis is unique among modern taxa for supporting both parturition of large brained young and obligate bipedalism. Though much work has focused on pelvic development and variation, little work has explored the presence or absence of asymmetry in the pelvis despite well-known patterns of asymmetry in other skeletal regions. This study investigated whether patterns of directional asymmetry (DA) could be observed in the pelvis or pelvic canal. Seventeen bilaterally paired osteometric measurements of the os coxae (34 measures in total) were taken from 128 skeletons (female n = 65, male n = 63) from recent human populations in five geographic regions. Paired sample t-tests and Mann-Whitney U-tests were used to investigate DA. Results from a pooled sample of all individuals showed that the pelvis exhibited a left-bias in DA. In contrast, the pelvic canal exhibited a pattern in which the anterior canal exhibited a right-bias and the posterior canal exhibited a left-bias. Neither sex nor populational differences in DA were observed in the pelvis or pelvic canal. The varying patterns of asymmetry uncovered here accord with prior work and may indicate that loading from the trunk and legs place differing stresses on the pelvis and canal, yielding these unequal asymmetries. However, this is speculative and the possible influence of genetics, biomechanics, and nutritional status on the development of pelvic and canal asymmetries presents a rich area for future study. Additionally, the potential influence of pelvic canal asymmetry on obstetric measures of pelvic capacity merits future research. Am. J. Hum. Biol. 28:804-810, 2016. © 2016Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

MEMS temperature scanner: principles, advances, and applications

NASA Astrophysics Data System (ADS)

Otto, Thomas; Saupe, Ray; Stock, Volker; Gessner, Thomas

2010-02-01

Contactless measurement of temperatures has gained enormous significance in many application fields, ranging from climate protection over quality control to object recognition in public places or military objects. Thereby measurement of linear or spatially temperature distribution is often necessary. For this purposes mostly thermographic cameras or motor driven temperature scanners are used today. Both are relatively expensive and the motor drive devices are limited regarding to the scanning rate additionally. An economic alternative are temperature scanner devices based on micro mirrors. The micro mirror, attached in a simple optical setup, reflects the emitted radiation from the observed heat onto an adapted detector. A line scan of the target object is obtained by periodic deflection of the micro scanner. Planar temperature distribution will be achieved by perpendicularly moving the target object or the scanner device. Using Planck radiation law the temperature of the object is calculated. The device can be adapted to different temperature ranges and resolution by using different detectors - cooled or uncooled - and parameterized scanner parameters. With the basic configuration 40 spatially distributed measuring points can be determined with temperatures in a range from 350°C - 1000°C. The achieved miniaturization of such scanners permits the employment in complex plants with high building density or in direct proximity to the measuring point. The price advantage enables a lot of applications, especially new application in the low-price market segment This paper shows principle, setup and application of a temperature measurement system based on micro scanners working in the near infrared range. Packaging issues and measurement results will be discussed as well.

Developmental spinal canal stenosis and somatotype.

PubMed Central

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

Ultrasonic Low-Friction Containment Plate for Thermal and Ultrasonic Stir Weld Processes

NASA Technical Reports Server (NTRS)

Graff, Karl; Short, Matt

2013-01-01

The thermal stir welding (TSW) process is finding applications in fabrication of space vehicles. In this process, workpieces to be joined by TSW are drawn, by heavy forces, between "containment plates," past the TSW tool that then causes joining of the separate plates. It is believed that the TSW process would be significantly improved by reducing the draw force, and that this could be achieved by reducing the friction forces between the workpieces and containment plates. Based on use of high-power ultrasonics in metal forming processes, where friction reduction in drawing dies has been achieved, it is believed that ultrasonic vibrations of the containment plates could achieve similar friction reduction in the TSW process. By applying ultrasonic vibrations to the containment plates in a longitudinal vibration mode, as well as by mounting and holding the containment plates in a specific manner such as to permit the plates to acoustically float, friction between the metal parts and the containment plates is greatly reduced, and so is the drawing force. The concept was to bring in the ultrasonics from the sides of the plates, permitting the ultrasonic hardware to be placed to the side, away from the equipment that contains the thermal stir tooling and that applies clamping forces to the plates. Tests demonstrated that one of the major objectives of applying ultrasonics to the thermal stir system, that of reducing draw force friction, should be achievable on a scaled-up system.

Shaping ability of nickel-titanium rotary instruments in curved root canals.

PubMed

Talati, Ali; Moradi, Saeed; Forghani, Maryam; Monajemzadeh, Ali

2013-01-01

Disinfection and subsequent obturation of the root canal space require adequate mechanical enlargement of the canals. The purpose of this in vitro study was to compare the shaping ability of Mtwo, RaCe and Medin rotary instruments during the preparation of curved root canals. Sixty mesiobuccal root canals of mandibular molars with severe curvatures between 25-35(°) and radius of 4-9 mm were randomly divided into three groups of 20 canals each. Using pre- and post-instrumentation radiographs, straightening of the canal and the apical transportation were determined with AutoCAD software. The data were analyzed using Chi square, analysis of variance, and post-hoc tests and the significance level was set at P<0.05. Mtwo instruments maintained the canal curvature significantly better than Race and Medin instruments (P<0.05). There was significant difference between the rotary instruments for iatrogenic transportation of the major foramen (P>0.05). Under the conditions of this in vitro study, Mtwo instruments seemed superior to the two other rotary instruments.

Scanner OPC signatures: automatic vendor-to-vendor OPE matching

NASA Astrophysics Data System (ADS)

Renwick, Stephen P.

2009-03-01

As 193nm lithography continues to be stretched and the k1 factor decreases, optical proximity correction (OPC) has become a vital part of the lithographer's tool kit. Unfortunately, as is now well known, the design variations of lithographic scanners from different vendors cause them to have slightly different optical-proximity effect (OPE) behavior, meaning that they print features through pitch in distinct ways. This in turn means that their response to OPC is not the same, and that an OPC solution designed for a scanner from Company 1 may or may not work properly on a scanner from Company 2. Since OPC is not inexpensive, that causes trouble for chipmakers using more than one brand of scanner. Clearly a scanner-matching procedure is needed to meet this challenge. Previously, automatic matching has only been reported for scanners of different tool generations from the same manufacturer. In contrast, scanners from different companies have been matched using expert tuning and adjustment techniques, frequently requiring laborious test exposures. Automatic matching between scanners from Company 1 and Company 2 has remained an unsettled problem. We have recently solved this problem and introduce a novel method to perform the automatic matching. The success in meeting this challenge required three enabling factors. First, we recognized the strongest drivers of OPE mismatch and are thereby able to reduce the information needed about a tool from another supplier to that information readily available from all modern scanners. Second, we developed a means of reliably identifying the scanners' optical signatures, minimizing dependence on process parameters that can cloud the issue. Third, we carefully employed standard statistical techniques, checking for robustness of the algorithms used and maximizing efficiency. The result is an automatic software system that can predict an OPC matching solution for scanners from different suppliers without requiring expert intervention.

Quantifying canal leakage rates using a mass-balance approach and heat-based hydraulic conductivity estimates in selected irrigation canals, western Nebraska, 2007 through 2009

USGS Publications Warehouse

Hobza, Christopher M.; Andersen, Michael J.

2010-01-01

The water supply in areas of the North Platte River Basin in the Nebraska Panhandle has been designated as fully appropriated or overappropriated by the Nebraska Department of Natural Resources (NDNR). Enacted legislation (Legislative Bill 962) requires the North Platte Natural Resources District (NPNRD) and the NDNR to develop an Integrated Management Plan (IMP) to balance groundwater and surface-water supply and demand in the NPNRD. A clear understanding of the groundwater and surface-water systems is critical for the development of a successful IMP. The primary source of groundwater recharge in parts of the NPNRD is from irrigation canal leakage. Because canal leakage constitutes a large part of the hydrologic budget, spatially distributing canal leakage to the groundwater system is important to any management strategy. Surface geophysical data collected along selected reaches of irrigation canals has allowed for the spatial distribution of leakage on a relative basis; however, the actual magnitude of leakage remains poorly defined. To address this need, the U.S. Geological Survey, in cooperation with the NPNRD, established streamflow-gaging stations at upstream and downstream ends from two selected canal reaches to allow a mass-balance approach to be used to calculate daily leakage rates. Water-level and sediment temperature data were collected and simulated at three temperature monitoring sites to allow the use of heat as a tracer to estimate the hydraulic conductivity of canal bed sediment. Canal-leakage rates were estimated by applying Darcy's Law to modeled vertical hydraulic conductivity and either the estimated or measured hydraulic gradient. This approach will improve the understanding of the spatial and temporal variability of canal leakage in varying geologic settings identified in capacitively coupled resistivity surveys. The high-leakage potential study reach of the Tri-State Canal had two streamflow-gaging stations and two temperature monitoring

Uncertainty Propagation for Terrestrial Mobile Laser Scanner

NASA Astrophysics Data System (ADS)

Mezian, c.; Vallet, Bruno; Soheilian, Bahman; Paparoditis, Nicolas

2016-06-01

Laser scanners are used more and more in mobile mapping systems. They provide 3D point clouds that are used for object reconstruction and registration of the system. For both of those applications, uncertainty analysis of 3D points is of great interest but rarely investigated in the literature. In this paper we present a complete pipeline that takes into account all the sources of uncertainties and allows to compute a covariance matrix per 3D point. The sources of uncertainties are laser scanner, calibration of the scanner in relation to the vehicle and direct georeferencing system. We suppose that all the uncertainties follow the Gaussian law. The variances of the laser scanner measurements (two angles and one distance) are usually evaluated by the constructors. This is also the case for integrated direct georeferencing devices. Residuals of the calibration process were used to estimate the covariance matrix of the 6D transformation between scanner laser and the vehicle system. Knowing the variances of all sources of uncertainties, we applied uncertainty propagation technique to compute the variance-covariance matrix of every obtained 3D point. Such an uncertainty analysis enables to estimate the impact of different laser scanners and georeferencing devices on the quality of obtained 3D points. The obtained uncertainty values were illustrated using error ellipsoids on different datasets.

Bony pelvic canal size and shape in relation to body proportionality in humans.

PubMed

Kurki, Helen K

2013-05-01

Obstetric selection acts on the female pelvic canal to accommodate the human neonate and contributes to pelvic sexual dimorphism. There is a complex relationship between selection for obstetric sufficiency and for overall body size in humans. The relationship between selective pressures may differ among populations of different body sizes and proportions, as pelvic canal dimensions vary among populations. Size and shape of the pelvic canal in relation to body size and shape were examined using nine skeletal samples (total female n = 57; male n = 84) from diverse geographical regions. Pelvic, vertebral, and lower limb bone measurements were collected. Principal component analyses demonstrate pelvic canal size and shape differences among the samples. Male multivariate variance in pelvic shape is greater than female variance for North and South Africans. High-latitude samples have larger and broader bodies, and pelvic canals of larger size and, among females, relatively broader medio-lateral dimensions relative to low-latitude samples, which tend to display relatively expanded inlet antero-posterior (A-P) and posterior canal dimensions. Differences in canal shape exist among samples that are not associated with latitude or body size, suggesting independence of some canal shape characteristics from body size and shape. The South Africans are distinctive with very narrow bodies and small pelvic inlets relative to an elongated lower canal in A-P and posterior lengths. Variation in pelvic canal geometry among populations is consistent with a high degree of evolvability in the human pelvis. Copyright © 2013 Wiley Periodicals, Inc.

Computer automation of ultrasonic testing. [inspection of ultrasonic welding

NASA Technical Reports Server (NTRS)

Yee, B. G. W.; Kerlin, E. E.; Gardner, A. H.; Dunmyer, D.; Wells, T. G.; Robinson, A. R.; Kunselman, J. S.; Walker, T. C.

1974-01-01

Report describes a prototype computer-automated ultrasonic system developed for the inspection of weldments. This system can be operated in three modes: manual, automatic, and computer-controlled. In the computer-controlled mode, the system will automatically acquire, process, analyze, store, and display ultrasonic inspection data in real-time. Flaw size (in cross-section), location (depth), and type (porosity-like or crack-like) can be automatically discerned and displayed. The results and pertinent parameters are recorded.

Comparative study of 6 rotary nickel-titanium systems and hand instrumentation for root canal preparation in severely curved root canals of extracted teeth.

PubMed

Celik, Davut; Taşdemir, Tamer; Er, Kürşat

2013-02-01

Some improvements have been developed with new generations of nickel-titanium (NiTi) rotary instruments that led to their successful and extensive application in clinical practice. The purpose of this in vitro study was to compare the root canal preparations performed by using GT Series X and Twisted File systems produced by innovative manufacturing process with Revo-S, RaCe, Mtwo, and ProTaper Universal systems manufactured directly from conventional nitinol and with stainless steel K-Flexofile instruments. The mesiobuccal root canals of 140 maxillary first permanent molars that had between 30°-40° curvature angle and 4- to 9-mm curvature radius of the root canal were used. After root canal preparations made by using GT Series X, Twisted File, Revo-S, RaCe, Mtwo, and ProTaper Universal NiTi rotary systems and stainless steel K-Flexofile instruments, transportation occurred in the root canal, and alteration of working length (WL) was assessed by using a modified double-digital radiographic technique. The data were compared by the post hoc Tukey honestly significant difference test. NiTi rotary systems caused less canal transportation and alteration of WL than K-Flexofile instruments (P < .05). There was no significant difference between NiTi rotary system groups at any levels (P > .05) except 2.5 mm from the WL. At this level ProTaper Universal system caused significant canal transportation (P < .05). GT Series X and Twisted File rotary systems produced with innovative process were concluded to shape the curved canals to result in minimal canal transportation, similar to Revo-S, RaCe, Mtwo, and ProTaper Universal rotary systems manufactured by traditional methods. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Effect of canal preparation with TRUShape and Vortex rotary instruments on three-dimensional geometry of oval root canals.

PubMed

Arias, Ana; Paqué, Frank; Shyn, Stephanie; Murphy, Sarah; Peters, Ove A

2018-04-01

The purpose of this study was to assess the geometry of non-round root canals after preparation with TRUShape (a novel instrument with s-shaped longitudinal design) in comparison to conventional rotary instrumentation using micro-computed tomography. Twenty distal root canals of mandibular molars were randomly distributed in two groups to be shaped with either TRUShape or Vortex rotaries. Percentages of unprepared surface and volume of dentin removal for the entire canal and for the apical 4 mm were calculated. Canal transportation and the structure model index (SMI) were assessed. Data were compared with Student t-tests. Shaping with both techniques resulted in similar prepared surface and volume of dentin removed, as well as the extent of canal transportation. The SMI shape factor was significantly lower for TRUShape preparations (P = 0.04) suggesting less rounding during rotary preparation. Although both instruments were suitable for the preparation of oval canals, TRUShape appeared to better conform to the original ribbon-shaped anatomy. © 2017 Australian Society of Endodontology Inc.

Applications of a nanocomposite-inspired in-situ broadband ultrasonic sensor to acousto-ultrasonics-based passive and active structural health monitoring.

PubMed

Liu, Menglong; Zeng, Zhihui; Xu, Hao; Liao, Yaozhong; Zhou, Limin; Zhang, Zhong; Su, Zhongqing

2017-07-01

A novel nanocomposite-inspired in-situ broadband ultrasonic sensor previously developed, with carbon black as the nanofiller and polyvinylidene fluoride as the matrix, was networked for acousto-ultrasonic wave-based passive and active structural health monitoring (SHM). Being lightweight and small, this kind of sensor was proven to be capable of perceiving strain perturbation in virtue of the tunneling effect in the formed nanofiller conductive network when acousto-ultrasonic waves traverse the sensor. Proof-of-concept validation was implemented, to examine the sensor performance in responding to acousto-ultrasonic waves in a broad frequency regime: from acoustic emission (AE) of lower frequencies to guided ultrasonic waves (GUWs) of higher frequencies. Results have demonstrated the high fidelity, ultrafast response and high sensitivity of the sensor to acousto-ultrasonic waves up to 400kHz yet with an ultra-low magnitude (of the order of micro-strain). The sensor is proven to possess sensitivity and accuracy comparable with commercial piezoelectric ultrasonic transducers, whereas with greater flexibility in accommodating curved structural surfaces. Application paradigms of using the sensor for damage evaluation have spotlighted the capability of the sensor in compromising "sensing cost" with "sensing effectiveness" for passive AE- or active GUW-based SHM. Copyright © 2017 Elsevier B.V. All rights reserved.

Ultrasonic drilling apparatus

DOEpatents

Duran, Edward L.; Lundin, Ralph L.

1989-01-01

Apparatus attachable to an ultrasonic drilling machine for drilling deep holes in very hard materials, such as boron carbide, is provided. The apparatus utilizes a hollow spindle attached to the output horn of the ultrasonic drilling machine. The spindle has a hollow drill bit attached at the opposite end. A housing surrounds the spindle, forming a cavity for holding slurry. In operation, slurry is provided into the housing, and into the spindle through inlets while the spindle is rotating and ultrasonically reciprocating. Slurry flows through the spindle and through the hollow drill bit to cleanse the cutting edge of the bit during a drilling operation.

Ultrasonic drilling apparatus

DOEpatents

Duran, E.L.; Lundin, R.L.

1988-06-20

Apparatus attachable to an ultrasonic drilling machine for drilling deep holes in very hard materials, such as boron carbide, is provided. The apparatus utilizes a hollow spindle attached to the output horn of the ultrasonic drilling machine. The spindle has a hollow drill bit attached at the opposite end. A housing surrounds the spindle, forming a cavity for holding slurry. In operation, slurry is provided into the housing, and into the spindle through inlets while the spindle is rotating and ultrasonically reciprocating. Slurry flows through the spindle and through the hollow drill bit to cleanse the cutting edge of the bit during a drilling operation. 3 figs.

Wedges for ultrasonic inspection

DOEpatents

Gavin, Donald A.

1982-01-01

An ultrasonic transducer device is provided which is used in ultrasonic inspection of the material surrounding a threaded hole and which comprises a wedge of plastic or the like including a curved threaded surface adapted to be screwed into the threaded hole and a generally planar surface on which a conventional ultrasonic transducer is mounted. The plastic wedge can be rotated within the threaded hole to inspect for flaws in the material surrounding the threaded hole.

Apical and root canal space sealing abilities of resin and glass ionomer-based root canal obturation systems.

PubMed

Royer, Kinga; Liu, Xue Jun; Zhu, Qiang; Malmstrom, Hans; Ren, Yan-Fang

2013-01-01

To investigate the apical sealing ability of glass ionomer and resin-based root canal obturation systems in comparison to a conventional vertical compaction of warm guttapercha. Forty-five extracted human teeth were randomly assigned into 3 groups of 15 each: a resin-based (EndoRez), a glass ionomer-based (Activ GP), and a conventional gutta-percha plus pulp sealer obturation system (GP/EWT). Apical and root canal space sealing abilities were assessed on five cross-sections 1.0 mm apart starting from the apex. Cross-section images were analysed using a focus-variation 3D scanning microscope and unsealed space was calculated as the percentage of total root canal space occupied by voids and debris. EndoRez had significantly higher rate of apical leakage and deeper dye penetration as compared to GP/EWT and Activ GP. EndoRez group had also more voids and debris (22.5%) in the root canal spaces as compared to GP/EWT (10.5%) and Activ GP (10.8%). Apical leakages occurred not only along the root canal walls, but also along the gutta-percha cones with EndoRez as a result of significant polymerisation shrinkage of the resin sealer. Resin-based EndoRez did not form an adequate apical seal of filled root canals. Glass ionomer-based Activ GP was comparable to a vertical compaction of warm guttapercha plus EWT sealer in sealing root canal spaces.

Scanner Art and Links to Physics

ERIC Educational Resources Information Center

Russell, David

2005-01-01

A photocopier or scanner can be used to produce not only the standard motion graphs of physics, but a variety of other graphs that resemble gravitational and electrical fields. This article presents a starting point for exploring scanner graphics, which brings together investigation in art and design, physics, mathematics, and information…

Method and means of transmitting and receiving broad-band unipolar, ultrasonic pulses for ultrasonic inspection

DOEpatents

Thompson, D.O.; Hsu, D.K.

1993-12-14

The invention includes a means and method for transmitting and receiving broadband, unipolar, ultrasonic pulses for ultrasonic inspection. The method comprises generating a generally unipolar ultrasonic stress pulse from a low impedance voltage pulse transmitter along a low impedance electrical pathway to an ultrasonic transducer, and receiving the reflected echo of the pulse by the transducer, converting it to a voltage signal, and passing it through a high impedance electrical pathway to an output. The means utilizes electrical components according to the method. The means and method allow a single transducer to be used in a pulse/echo mode, and facilitates alternatingly transmitting and receiving the broadband, unipolar, ultrasonic pulses. 25 figures.

Superwide-angle coverage code-multiplexed optical scanner.

PubMed

Riza, Nabeel A; Arain, Muzammil A

2004-05-01

A superwide-angle coverage code-multiplexed optical scanner is presented that has the potential to provide 4 pi-sr coverage. As a proof-of-concept experiment, an angular scan range of 288 degrees for six randomly distributed beams is demonstrated. The proposed scanner achieves its superwide coverage by exploiting a combination of phase-encoded transmission and reflection holography within an in-line hologram recording-retrieval geometry. The basic scanner unit consists of one phase-only digital mode spatial light modulator for code entry (i.e., beam scan control) and a holographic material from which we obtained what we believe is the first-of-a-kind extremely wide coverage, low component count, high speed (e.g., microsecond domain), and large aperture (e.g., > 1-cm diameter) scanner.

Root Canal Treatment of Mandibular Second Premolar with Three Separate Roots and Canals Using Spiral Computed Tomographic

PubMed Central

Hariharavel, V. P.; Kumar, A. Ashok; Ganesh, C.; Aravindhan, R.

2014-01-01

Anatomic and internal morphology of a root canal system is more complex and differs for each individual tooth of which mandibular premolars have earned the reputation for having aberrant anatomy. The occurrence of three canals with three separate foramina in mandibular second premolars is very rare. A wider knowledge on both clinical and radiological anatomy especially spiral computed tomographic is absolutely essential for the success of endodontic treatment. These teeth may require skillful and special root canal special shaping and obturating techniques. This paper reports an unusual case of a mandibular second premolar with atypical canal pattern that was successfully treated endodontically. PMID:25101187

Out-of-plane ultrasonic velocity measurement

DOEpatents

Hall, Maclin S.; Brodeur, Pierre H.; Jackson, Theodore G.

1998-01-01

A method for improving the accuracy of measuring the velocity and time of flight of ultrasonic signals through moving web-like materials such as paper, paperboard and the like, includes a pair of ultrasonic transducers disposed on opposing sides of a moving web-like material. In order to provide acoustical coupling between the transducers and the web-like material, the transducers are disposed in fluid-filled wheels. Errors due to variances in the wheel thicknesses about their circumference which can affect time of flight measurements and ultimately the mechanical property being tested are compensated by averaging the ultrasonic signals for a predetermined number of revolutions. The invention further includes a method for compensating for errors resulting from the digitization of the ultrasonic signals. More particularly, the invention includes a method for eliminating errors known as trigger jitter inherent with digitizing oscilloscopes used to digitize the signals for manipulation by a digital computer. In particular, rather than cross-correlate ultrasonic signals taken during different sample periods as is known in the art in order to determine the time of flight of the ultrasonic signal through the moving web, a pulse echo box is provided to enable cross-correlation of predetermined transmitted ultrasonic signals with predetermined reflected ultrasonic or echo signals during the sample period. By cross-correlating ultrasonic signals in the same sample period, the error associated with trigger jitter is eliminated.

An Improved Scheduling Algorithm for Data Transmission in Ultrasonic Phased Arrays with Multi-Group Ultrasonic Sensors

PubMed Central

Tang, Wenming; Liu, Guixiong; Li, Yuzhong; Tan, Daji

2017-01-01

High data transmission efficiency is a key requirement for an ultrasonic phased array with multi-group ultrasonic sensors. Here, a novel FIFOs scheduling algorithm was proposed and the data transmission efficiency with hardware technology was improved. This algorithm includes FIFOs as caches for the ultrasonic scanning data obtained from the sensors with the output data in a bandwidth-sharing way, on the basis of which an optimal length ratio of all the FIFOs is achieved, allowing the reading operations to be switched among all the FIFOs without time slot waiting. Therefore, this algorithm enhances the utilization ratio of the reading bandwidth resources so as to obtain higher efficiency than the traditional scheduling algorithms. The reliability and validity of the algorithm are substantiated after its implementation in the field programmable gate array (FPGA) technology, and the bandwidth utilization ratio and the real-time performance of the ultrasonic phased array are enhanced. PMID:29035345

Ultrasonic Transducer Irradiation Test Results

DOE Office of Scientific and Technical Information (OSTI.GOV)

Daw, Joshua; Palmer, Joe; Ramuhalli, Pradeep

2015-02-01

Ultrasonic technologies offer the potential for high-accuracy and -resolution in-pile measurement of a range of parameters, including geometry changes, temperature, crack initiation and growth, gas pressure and composition, and microstructural changes. Many Department of Energy-Office of Nuclear Energy (DOE-NE) programs are exploring the use of ultrasonic technologies to provide enhanced sensors for in-pile instrumentation during irradiation testing. For example, the ability of small diameter ultrasonic thermometers (UTs) to provide a temperature profile in candidate metallic and oxide fuel would provide much needed data for validating new fuel performance models. Other ongoing efforts include an ultrasonic technique to detect morphology changesmore » (such as crack initiation and growth) and acoustic techniques to evaluate fission gas composition and pressure. These efforts are limited by the lack of identified ultrasonic transducer materials capable of long term performance under irradiation test conditions. For this reason, the Pennsylvania State University (PSU) was awarded an ATR NSUF project to evaluate the performance of promising magnetostrictive and piezoelectric transducers in the Massachusetts Institute of Technology Research Reactor (MITR) up to a fast fluence of at least 10 21 n/cm 2. The goal of this research is to characterize and demonstrate magnetostrictive and piezoelectric transducer operation during irradiation, enabling the development of novel radiation-tolerant ultrasonic sensors for use in Material Testing Reactors (MTRs). As such, this test is an instrumented lead test and real-time transducer performance data is collected along with temperature and neutron and gamma flux data. The current work bridges the gap between proven out-of-pile ultrasonic techniques and in-pile deployment of ultrasonic sensors by acquiring the data necessary to demonstrate the performance of ultrasonic transducers. To date, one piezoelectric transducer and two

Irradiation Testing of Ultrasonic Transducers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Daw, Joshua; Tittmann, Bernhard; Reinhardt, Brian

2014-07-30

Ultrasonic technologies offer the potential for high accuracy and resolution in-pile measurement of a range of parameters, including geometry changes, temperature, crack initiation and growth, gas pressure and composition, and microstructural changes. Many Department of Energy-Office of Nuclear Energy (DOE-NE) programs are exploring the use of ultrasonic technologies to provide enhanced sensors for in-pile instrumentation during irradiation testing. For example, the ability of single, small diameter ultrasonic thermometers (UTs) to provide a temperature profile in candidate metallic and oxide fuel would provide much needed data for validating new fuel performance models. Other efforts include an ultrasonic technique to detect morphologymore » changes (such as crack initiation and growth) and acoustic techniques to evaluate fission gas composition and pressure. These efforts are limited by the lack of existing knowledge of ultrasonic transducer material survivability under irradiation conditions. For this reason, the Pennsylvania State University (PSU) was awarded an Advanced Test Reactor National Scientific User Facility (ATR NSUF) project to evaluate promising magnetostrictive and piezoelectric transducer performance in the Massachusetts Institute of Technology Research Reactor (MITR) up to a fast fluence of at least 1021 n/cm2 (E> 0.1 MeV). The goal of this research is to characterize magnetostrictive and piezoelectric transducer survivability during irradiation, enabling the development of novel radiation tolerant ultrasonic sensors for use in Material and Test Reactors (MTRs). As such, this test will be an instrumented lead test and real-time transducer performance data will be collected along with temperature and neutron and gamma flux data. The current work bridges the gap between proven out-of-pile ultrasonic techniques and in-pile deployment of ultrasonic sensors by acquiring the data necessary to demonstrate the performance of ultrasonic transducers.« less

Temporal and Spatial Variation of Chemical Water Quality in a Contour Canal.

NASA Astrophysics Data System (ADS)

Swanson, L. A.; Lunn, R. J.

2004-12-01

Chemical water quality is a highly variable aspect of any water body. Historically numerous researchers have investigated the chemical variability of rivers, streams and wetlands, artificial water bodies such as canals have been largely neglected. Canals are typically hydraulically characterised by low flows and a lack of mixing processes. This can potentially lead to significant spatial variability in water chemistry, and as a result many canals in the UK regularly fail water quality targets at specific locations. Recent changes to UK legislation, following the European Water Framework Directive (2000/60/EC), have resulted in canals being subject to achieving `good ecological status'. In the case of canals, what constitutes `good ecological status' is largely unknown and little expertise is available since historically canal management has not been driven by chemical and ecological quality targets. Consequently, there is an urgent need for new research to determine the main factors influencing canal water quality and their ecological status. This research presents results from a study based on a UK contour canal, the Union Canal in central Scotland. The Union Canal typically demonstrates spatially and temporally variable levels of dissolved oxygen (DO) and orthophosphate (PO4-P): simultaneously, seasonal and diel fluctuations of DO and PO4-P are pronounced at a small number of locations. During 1995, minimum levels of DO along the canal length ranged from 9mgl-1 in Edinburgh to as low as 2mgl-1 approximately 20kms away, this then rose again to 8mgl-1 after a further distance of 2km. These acutely low levels of DO are coupled with events of excessive PO4-P up to 0.235mgl-1:10 times greater than those normally found in rivers, causing localised eutrophication and extensive fish kills. To determine the cause of the `hot spots' of poor water quality found on the Union Canal, simultaneous investigations of the hydraulic regime, spatial and temporal water quality

Errors in measurements by ultrasonic thickness gauges caused by the variation in ultrasonic velocity in constructional steels and metal alloys

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kalinin, V.A.; Tarasenko, V.L.; Tselser, L.B.

1988-09-01

Numerical values of the variation in ultrasonic velocity in constructional metal alloys and the measurement errors related to them are systematized. The systematization is based on the measurement results of the group ultrasonic velocity made in the All-Union Scientific-Research Institute for Nondestructive Testing in 1983-1984 and also on the measurement results of the group velocity made by various authors. The variations in ultrasonic velocity were systematized for carbon, low-alloy, and medium-alloy constructional steels; high-alloy iron base alloys; nickel-base heat-resistant alloys; wrought aluminum constructional alloys; titanium alloys; and cast irons and copper alloys.

Canal transportation and centering ability of protaper and self-adjusting file system in long oval canals: An ex-vivo cone-beam computed tomography analysis.

PubMed

Shah, Dipali Yogesh; Wadekar, Swati Ishwara; Dadpe, Ashwini Manish; Jadhav, Ganesh Ranganath; Choudhary, Lalit Jayant; Kalra, Dheeraj Deepak

2017-01-01

The purpose of this study was to compare and evaluate the shaping ability of ProTaper (PT) and Self-Adjusting File (SAF) system using cone-beam computed tomography (CBCT) to assess their performance in oval-shaped root canals. Sixty-two mandibular premolars with single oval canals were divided into two experimental groups ( n = 31) according to the systems used: Group I - PT and Group II - SAF. Canals were evaluated before and after instrumentation using CBCT to assess centering ratio and canal transportation at three levels. Data were statistically analyzed using one-way analysis of variance, post hoc Tukey's test, and t -test. The SAF showed better centering ability and lesser canal transportation than the PT only in the buccolingual plane at 6 and 9 mm levels. The shaping ability of the PT was best in the apical third in both the planes. The SAF had statistically significant better centering and lesser canal transportation in the buccolingual as compared to the mesiodistal plane at the middle and coronal levels. The SAF produced significantly less transportation and remained centered than the PT at the middle and coronal levels in the buccolingual plane of oval canals. In the mesiodistal plane, the performance of both the systems was parallel.

Cervical spinal canal narrowing in idiopathic syringomyelia.

PubMed

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.

Canalolithiasis of the superior semicircular canal: an anomaly in benign paroxysmal vertigo.

PubMed

Schratzenstaller, Bruno; Wagner-Manslau, Carola; Strasser, Gerhard; Arnold, Wolfgang

2005-10-01

According to the canalolithiasis theory, benign paroxysmal vertigo (BPPV) is caused by gravity-dependent movements of otoconial debris that collects in the endolymph of the posterior semicircular canal. Other parts of the vestibular organ are rarely affected, and it is mainly the horizontal canal that is affected by this atypical form of BPPV. Canalolithiasis of the superior semicircular canal must be considered an anomaly because the superior semicircular canal is the highest point of the vestibular organ and debris normally cannot collect in this special location. Until now, BPPV of the superior canal has mainly been dealt with theoretically in the literature. The authors present three patients with canalolithiasis of the superior semicircular canal and offer direct proof of the condition using high-resolution 3D MRI.

Multi-Source 3d Models Supporting Ultrasonic Test to Investigate AN Egyptian Sculpture of the Archaeological Museum in Bologna

NASA Astrophysics Data System (ADS)

Di Pietra, V.; Donadio, E.; Picchi, D.; Sambuelli, L.; Spanò, A.

2017-02-01

The paper presents the workflow and the results of an ultrasonic 3D investigation and a 3D survey application aimed at the assessment of the internal integrity of an ancient sculpture. The work aimed at highlighting the ability of methods devoted to the 3D geometry acquisition of small objects when applied to diagnosis performed by geophysical investigation. In particular, two methods widely applied for small objects modelling are considered and compared, the digital Photogrammetry with the Structure from Motion (SFM) technique and hand-held 3D scanners. The study concludes with the aim to enhance the final graphical representation of the tomographic results and to subject the obtained results to a quantitative analysis. The survey is applied to the Egyptian naophorous statue of Amenmes and Reshpu, which dates to the reign of Ramses II (1279-1213 BC) or later and is now preserved in the Civic Archaeological Museum in Bologna. In order to evaluate the internal persistency of fractures and visible damages, a 3D Ultrasonic Tomographic Imaging (UTI) test has been performed and a multi-sensor survey (image and range based) was conducted, in order to evaluate the locations of the source and receiver points as accurate as possible The presented test allowed to evaluate the material characteristics, its porosity and degradation state, which particularly affect the lower part of the statue. More in general, the project demonstrated how solution coming from the field of 3D modelling of Cultural Heritage allow the application of 3D ultrasonic tomography also on objects with complex shapes, in addition to the improved representation of the obtained results.

NEET In-Pile Ultrasonic Sensor Enablement-Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

J. Daw; J. Rempe; J. Palmer

2014-09-01

Ultrasonic technologies offer the potential to measure a range of parameters during irradiation of fuels and materials, including geometry changes, temperature, crack initiation and growth, gas pressure and composition, and microstructural changes under harsh irradiation test conditions. There are two primary issues that currently limit in-pile deployment of ultrasonic sensors. The first is transducer survivability. The ability of ultrasonic transducer materials to maintain their useful properties during an irradiation must be demonstrated. The second issue is signal processing. Ultrasonic testing is typically performed in a lab or field environment, where the sensor and sample are accessible. The harsh nature ofmore » in-pile testing and the variety of desired measurements demand that an enhanced signal processing capability be developed to make in-pile ultrasonic sensors viable. To address these issues, the NEET ASI program funded a three year Ultrasonic Transducer Irradiation and Signal Processing Enhancements project, which is a collaborative effort between the Idaho National Laboratory, the Pacific Northwest National Laboratory, the Argonne National Laboratory, and the Pennsylvania State University. The objective of this report is to document the objectives and accomplishments from this three year project. As summarized within this document, significant work has been accomplished during this three year project.« less

Ultrasonic search wheel probe

DOEpatents

Mikesell, Charles R.

1978-01-01

A device is provided for reducing internal reflections from the tire of an ultrasonic search wheel probe or from within the material being examined. The device includes a liner with an anechoic chamber within which is an ultrasonic transducer. The liner is positioned within the wheel and includes an aperture through which the ultrasonic sound from the transducer is directed.

Comparison of Epson scanner quality for radiochromic film evaluation.

PubMed

Alnawaf, Hani; Yu, Peter K N; Butson, Martin

2012-09-06

Epson Desktop scanners have been quoted as devices which match the characteristics required for the evaluation of radiation dose exposure by radiochromic films. Specifically, models such as the 10000XL have been used successfully for image analysis and are recommended by ISP for dosimetry purposes. This note investigates and compares the scanner characteristics of three Epson desktop scanner models including the Epson 10000XL, V700, and V330. Both of the latter are substantially cheaper models capable of A4 scanning. As the price variation between the V330 and the 10000XL is 20-fold (based on Australian recommended retail price), cost savings by using the cheaper scanners may be warranted based on results. By a direct comparison of scanner uniformity and reproducibility we can evaluate the accuracy of these scanners for radiochromic film dosimetry. Results have shown that all three scanners can produce adequate scanner uniformity and reproducibility, with the inexpensive V330 producing a standard deviation variation across its landscape direction of 0.7% and 1.2% in the portrait direction (reflection mode). This is compared to the V700 in reflection mode of 0.25% and 0.5% for landscape and portrait directions, respectively, and 0.5% and 0.8% for the 10000XL. In transmission mode, the V700 is comparable in reproducibility to the 10000XL for portrait and landscape mode, whilst the V330 is only capable of scanning in the landscape direction and produces a standard deviation in this direction of 1.0% compared to 0.6% (V700) and 0.25% (10000XL). Results have shown that the V700 and 10000XL are comparable scanners in quality and accuracy with the 10000XL obviously capable of imaging over an A3 area as opposed to an A4 area for the V700. The V330 scanner produced slightly lower accuracy and quality with uncertainties approximately twice as much as the other scanners. However, the results show that the V330 is still an adequate scanner and could be used for radiation

Root and canal morphology of mandibular third molars in an Iranian population.

PubMed

Kuzekanani, Maryam; Haghani, Jahangir; Nosrati, Hossein

2012-01-01

A through knowledge of the root canal morphology is required for successful endodontic ther-apy. The aim of this study was to investigate the root and canal morphology of mandibular third molars in Kerman, a prov-ince in southeast of Iran. One-hundred-fifty extracted mandibular third molars were collected randomly from different dental clinics in Kerman. The root canal anatomy and morphology of each tooth was carefully studied using a clearing tech-nique. Root number and morphology, number of canals per root, root canal configuration according to Vertucci classifica-tion, and incidence of dilacerated roots and C-shaped canals in mandibular third molars were evaluated under stereomicro-scope with ×2 to ×3 magnifications. From the total of 150 mandibular third molars studied, 21% had one root. The majority of teeth (73%) had two roots. 5.5% of the teeth had three roots. The incidence of C-shaped canal was 3.5% in this study and 8% of the teeth had at least one dilacerated root. Although root canal anatomy and morphology of mandibular third molars is very variable having two roots seems to be the normal anatomy for these teeth.

Maxillary first molar with five canals

PubMed Central

Umer, Fahad

2014-01-01

Root canal treatment is a technically demanding procedure especially in the case of maxillary first molar where the anatomy is extremely variable. Failure to recognise and treat these variations may lead to unpredictable outcomes. This case report describes non-surgical endodontic treatment of a maxillary first molar with two palatal and two mesiobuccal canals. It also highlights the need for good anatomical knowledge of root canal morphology and its variations in order to achieve consistently successful results. PMID:25239993

A PC-based multispectral scanner data evaluation workstation: Application to Daedalus scanners

NASA Technical Reports Server (NTRS)

Jedlovec, Gary J.; James, Mark W.; Smith, Matthew R.; Atkinson, Robert J.

1991-01-01

In late 1989, a personal computer (PC)-based data evaluation workstation was developed to support post flight processing of Multispectral Atmospheric Mapping Sensor (MAMS) data. The MAMS Quick View System (QVS) is an image analysis and display system designed to provide the capability to evaluate Daedalus scanner data immediately after an aircraft flight. Even in its original form, the QVS offered the portability of a personal computer with the advanced analysis and display features of a mainframe image analysis system. It was recognized, however, that the original QVS had its limitations, both in speed and processing of MAMS data. Recent efforts are presented that focus on overcoming earlier limitations and adapting the system to a new data tape structure. In doing so, the enhanced Quick View System (QVS2) will accommodate data from any of the four spectrometers used with the Daedalus scanner on the NASA ER2 platform. The QVS2 is designed around the AST 486/33 MHz CPU personal computer and comes with 10 EISA expansion slots, keyboard, and 4.0 mbytes of memory. Specialized PC-McIDAS software provides the main image analysis and display capability for the system. Image analysis and display of the digital scanner data is accomplished with PC-McIDAS software.

Ultrasonic dip seal maintenance system

DOEpatents

Poindexter, Allan M.; Ricks, Herbert E.

1978-01-01

A system for removing impurities from the surfaces of liquid dip seals and or wetting the metal surfaces of liquid dip seals in nuclear components. The system comprises an ultrasonic transducer that transmits ultrasonic vibrations along an ultrasonic probe to the metal and liquid surfaces of the dip seal thereby loosening and removing those impurities.

Ultrasonic neuromodulation

NASA Astrophysics Data System (ADS)

Naor, Omer; Krupa, Steve; Shoham, Shy

2016-06-01

Ultrasonic waves can be non-invasively steered and focused into mm-scale regions across the human body and brain, and their application in generating controlled artificial modulation of neuronal activity could therefore potentially have profound implications for neural science and engineering. Ultrasonic neuro-modulation phenomena were experimentally observed and studied for nearly a century, with recent discoveries on direct neural excitation and suppression sparking a new wave of investigations in models ranging from rodents to humans. In this paper we review the physics, engineering and scientific aspects of ultrasonic fields, their control in both space and time, and their effect on neuronal activity, including a survey of both the field’s foundational history and of recent findings. We describe key constraints encountered in this field, as well as key engineering systems developed to surmount them. In closing, the state of the art is discussed, with an emphasis on emerging research and clinical directions.

Clinical significance of dental root canal microflora.

PubMed

Gomes, B P; Lilley, J D; Drucker, D B

1996-01-01

Previous work by this group has shown that a significant association exists between pain and the presence of either Prevotella or Peptostreptococcus spp. in dental root canals. The aim of this study was to examine a more extensive series of canals microbiologically, to determine whether any other particular endodontic symptoms or clinical signs showed specific associations with individual bacterial species. Seventy root canals were examined microbiologically and clinical data collected to investigate in detail such associations. Of the canals studied, 37 were associated with pain, 49 with tenderness to percussion, 23 with swelling, six with purulent exudate and 57 presented with wet root canals. Anaerobes were isolated from 70.3% of painful canals and from 29.7% of pain-free canals. Significant associations were found between (a) pain and either Prevotella spp. or peptostreptococci, both with P < 0.01; (b) tenderness to percussion and Prevotella spp. (P < 0.01) or anaerobes (P < 0.05); (c) swelling and Eubacterium spp. (P < 0.01), or with Prevotella spp. or Pstr. micros, both with P < 0.05; (d) purulent exudate and any one of F. necrophorum (P < 0.01), Prev. loescheii, Streptoccoccus constellatus or Bacteroides spp. (each P < 0.05); (e) wet canal and facultative anaerobes (P < 0.01), and any one of the genera of Eubacterium, Peptostreptococcus, Prevotella or Propionibacterium (each P < 0.05). It was concluded that several different endodontic clinical signs and symptoms are significantly associated with specific bacterial species.

Methods for CT automatic exposure control protocol translation between scanner platforms.

PubMed

McKenney, Sarah E; Seibert, J Anthony; Lamba, Ramit; Boone, John M

2014-03-01

An imaging facility with a diverse fleet of CT scanners faces considerable challenges when propagating CT protocols with consistent image quality and patient dose across scanner makes and models. Although some protocol parameters can comfortably remain constant among scanners (eg, tube voltage, gantry rotation time), the automatic exposure control (AEC) parameter, which selects the overall mA level during tube current modulation, is difficult to match among scanners, especially from different CT manufacturers. Objective methods for converting tube current modulation protocols among CT scanners were developed. Three CT scanners were investigated, a GE LightSpeed 16 scanner, a GE VCT scanner, and a Siemens Definition AS+ scanner. Translation of the AEC parameters such as noise index and quality reference mAs across CT scanners was specifically investigated. A variable-diameter poly(methyl methacrylate) phantom was imaged on the 3 scanners using a range of AEC parameters for each scanner. The phantom consisted of 5 cylindrical sections with diameters of 13, 16, 20, 25, and 32 cm. The protocol translation scheme was based on matching either the volumetric CT dose index or image noise (in Hounsfield units) between two different CT scanners. A series of analytic fit functions, corresponding to different patient sizes (phantom diameters), were developed from the measured CT data. These functions relate the AEC metric of the reference scanner, the GE LightSpeed 16 in this case, to the AEC metric of a secondary scanner. When translating protocols between different models of CT scanners (from the GE LightSpeed 16 reference scanner to the GE VCT system), the translation functions were linear. However, a power-law function was necessary to convert the AEC functions of the GE LightSpeed 16 reference scanner to the Siemens Definition AS+ secondary scanner, because of differences in the AEC functionality designed by these two companies. Protocol translation on the basis of

Out-of-plane ultrasonic velocity measurement

DOEpatents

Hall, M.S.; Brodeur, P.H.; Jackson, T.G.

1998-07-14

A method for improving the accuracy of measuring the velocity and time of flight of ultrasonic signals through moving web-like materials such as paper, paperboard and the like, includes a pair of ultrasonic transducers disposed on opposing sides of a moving web-like material. In order to provide acoustical coupling between the transducers and the web-like material, the transducers are disposed in fluid-filled wheels. Errors due to variances in the wheel thicknesses about their circumference which can affect time of flight measurements and ultimately the mechanical property being tested are compensated by averaging the ultrasonic signals for a predetermined number of revolutions. The invention further includes a method for compensating for errors resulting from the digitization of the ultrasonic signals. More particularly, the invention includes a method for eliminating errors known as trigger jitter inherent with digitizing oscilloscopes used to digitize the signals for manipulation by a digital computer. In particular, rather than cross-correlate ultrasonic signals taken during different sample periods as is known in the art in order to determine the time of flight of the ultrasonic signal through the moving web, a pulse echo box is provided to enable cross-correlation of predetermined transmitted ultrasonic signals with predetermined reflected ultrasonic or echo signals during the sample period. By cross-correlating ultrasonic signals in the same sample period, the error associated with trigger jitter is eliminated. 20 figs.

Ultrasonic Methods for Human Motion Detection

DTIC Science & Technology

2006-10-01

contacts. The active method utilizes continuous wave ultrasonic Doppler sonar . Human motions have unique Doppler signatures and their combination...The present article reports results of human motion investigations with help of CW ultrasonic Doppler sonar . Low-cost, low-power ultrasonic motion...have been developed for operation in air [10]. Benefits of using ultrasonic CW Doppler sonar included the low-cost, low-electric noise, small size

Sparse signal representation and its applications in ultrasonic NDE.

PubMed

Zhang, Guang-Ming; Zhang, Cheng-Zhong; Harvey, David M

2012-03-01

Many sparse signal representation (SSR) algorithms have been developed in the past decade. The advantages of SSR such as compact representations and super resolution lead to the state of the art performance of SSR for processing ultrasonic non-destructive evaluation (NDE) signals. Choosing a suitable SSR algorithm and designing an appropriate overcomplete dictionary is a key for success. After a brief review of sparse signal representation methods and the design of overcomplete dictionaries, this paper addresses the recent accomplishments of SSR for processing ultrasonic NDE signals. The advantages and limitations of SSR algorithms and various overcomplete dictionaries widely-used in ultrasonic NDE applications are explored in depth. Their performance improvement compared to conventional signal processing methods in many applications such as ultrasonic flaw detection and noise suppression, echo separation and echo estimation, and ultrasonic imaging is investigated. The challenging issues met in practical ultrasonic NDE applications for example the design of a good dictionary are discussed. Representative experimental results are presented for demonstration. Copyright © 2011 Elsevier B.V. All rights reserved.

Experimental selective posterior semicircular canal laser deafferentation.

PubMed

Naguib, Maged B

2005-05-01

In this experimental study, we attempted to perform selective deafferentation of the posterior semicircular canal ampulla of guinea pigs using carbon dioxide laser beam. The results of this study document the efficacy of this procedure in achieving deafferentation of the posterior semicircular canal safely with regards to the other semicircular canals, the otolithic organ and the organ of hearing. Moreover, the procedure is performed with relative ease compared with other procedures previously described for selective deafferentation of the posterior semicircular canal. The clinical application of such a procedure for the treatment of intractable benign paroxysmal positional vertigo in humans is suggested.

Ultrasonic liquid level detector

DOEpatents

Kotz, Dennis M.; Hinz, William R.

2010-09-28

An ultrasonic liquid level detector for use within a shielded container, the detector being tubular in shape with a chamber at its lower end into which liquid from in the container may enter and exit, the chamber having an ultrasonic transmitter and receiver in its top wall and a reflector plate or target as its bottom wall whereby when liquid fills the chamber a complete medium is then present through which an ultrasonic wave may be transmitted and reflected from the target thus signaling that the liquid is at chamber level.

Designing an in-situ ultrasonic nondestructive evaluation system for ultrasonic additive manufacturing

NASA Astrophysics Data System (ADS)

Nadimpalli, Venkata K.; Nagy, Peter B.

2018-04-01

Ultrasonic Additive Manufacturing (UAM) is a solid-state layer by layer manufacturing process that utilizes vibration induced plastic deformation to form a metallurgical bond between a thin layer and an existing base structure. Due to the vibration based bonding mechanism, the quality of components at each layer depends on the geometry of the structure. In-situ monitoring during and between UAM manufacturing steps offers the potential for closed-loop control to optimize process parameters and to repair existing defects. One interface that is most prone to delamination is the base/build interface and often UAM component height and quality are limited by failure at the base/build interface. Low manufacturing temperatures and favorable orientation of typical interface defects in UAM make ultrasonic NDE an attractive candidate for online monitoring. Two approaches for in-situ NDE are discussed and the design of the monitoring system optimized so that the quality of UAM components is not affected by the addition of the NDE setup. Preliminary results from in-situ ultrasonic NDE indicate the potential to be utilized for online qualification, closed-loop control and offline certification of UAM components.

Separation of metal ions in nitrate solution by ultrasonic atomization

NASA Astrophysics Data System (ADS)

Sato, Masanori; Ikeno, Masayuki; Fujii, Toshitaka

2004-11-01

In the ultrasonic atomization of metal nitrate solutions, the molar ratio of metal ions is changed between solution and mist. Small molar metal ions tend to be transferred to mist by ultrasonic wave acceleration, while large molar ions tend to remain in solution. As a result, metal ions can be separated by ultrasonic atomization. We show experimental data and propose a conceptual mechanism for the ultrasonic separation of metal ions.

Stress measurement in thick plates using nonlinear ultrasonics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abbasi, Zeynab, E-mail: zabbas5@uic.edu, E-mail: dozevin@uic.edu; Ozevin, Didem, E-mail: zabbas5@uic.edu, E-mail: dozevin@uic.edu

2015-03-31

In this paper the interaction between nonlinear ultrasonic characteristics and stress state of complex loaded thick steel plates using fundamental theory of nonlinear ultrasonics is investigated in order to measure the stress state at a given cross section. The measurement concept is based on phased array placement of ultrasonic transmitter-receiver to scan three angles of a given cross section using Rayleigh waves. The change in the ultrasonic data in thick steel plates is influenced by normal and shear stresses; therefore, three measurements are needed to solve the equations simultaneously. Different thickness plates are studied in order to understand the interactionmore » of Rayleigh wave penetration depth and shear stress. The purpose is that as the thickness becomes smaller, the shear stress becomes negligible at the angled measurement. For thicker cross section, shear stress becomes influential if the depth of penetration of Rayleigh wave is greater than the half of the thickness. The influences of plate thickness and ultrasonic frequency on the identification of stress tensor are numerically studied in 3D structural geometry and Murnaghan material model. The experimental component of this study includes uniaxial loading of the plate while measuring ultrasonic wave at three directions (perpendicular, parallel and angled to the loading direction). Instead of rotating transmitter-receiver pair for each test, a device capable of measuring the three angles is designed.« less

Prevalence of C-Shaped Root Canals in Iranian Population: A Systematic Review

PubMed Central

Naseri, Mandana; Haghighi, Ali Kangarlou; Kharazifard, Mohammad Javad; Khavid, Atefeh

2013-01-01

Objective: Because of the great challenges in the diagnosis and treatment of “C” configuration and lack of any systematic information about its occurrence, the purpose of the present study is to determine the prevalence of C shaped root canals in Iranian population. Methodology: An exhaustive search was undertaken to identify published and unpublished researches related to the C-shaped canals by using key words. The search of the MEDLINE database included all publications from 1966 to May 2012.Then selected articles were obtained and reviewed. Data evaluated and summarized in the data sheet included methodology, population, number of teeth per study (power), number of root canals, type of root canal configuration, and c-shaped canals. Results: Six studies were included with total of 1062 teeth, all in mandibular second molars. The total incidence of C-shaped canals in Iranian population was obtained 6.96%. Conclusions: The incidence of C-shaped canals in Iranian population is 6.96%, which seems much less than Asian populations but nearer to Middle East countries. PMID:23724219

Canal transportation and centering ability of protaper and self-adjusting file system in long oval canals: An ex-vivo cone-beam computed tomography analysis

PubMed Central

Shah, Dipali Yogesh; Wadekar, Swati Ishwara; Dadpe, Ashwini Manish; Jadhav, Ganesh Ranganath; Choudhary, Lalit Jayant; Kalra, Dheeraj Deepak

2017-01-01

Context and Aims: The purpose of this study was to compare and evaluate the shaping ability of ProTaper (PT) and Self-Adjusting File (SAF) system using cone-beam computed tomography (CBCT) to assess their performance in oval-shaped root canals. Materials and Methods: Sixty-two mandibular premolars with single oval canals were divided into two experimental groups (n = 31) according to the systems used: Group I – PT and Group II – SAF. Canals were evaluated before and after instrumentation using CBCT to assess centering ratio and canal transportation at three levels. Data were statistically analyzed using one-way analysis of variance, post hoc Tukey's test, and t-test. Results: The SAF showed better centering ability and lesser canal transportation than the PT only in the buccolingual plane at 6 and 9 mm levels. The shaping ability of the PT was best in the apical third in both the planes. The SAF had statistically significant better centering and lesser canal transportation in the buccolingual as compared to the mesiodistal plane at the middle and coronal levels. Conclusions: The SAF produced significantly less transportation and remained centered than the PT at the middle and coronal levels in the buccolingual plane of oval canals. In the mesiodistal plane, the performance of both the systems was parallel. PMID:28855757

Regulation of drainage canals on the groundwater level in a typical coastal wetlands

NASA Astrophysics Data System (ADS)

Liu, Qiang; Mou, Xia; Cui, Baoshan; Ping, Fan

2017-12-01

Activities related to reclamation alter wetland hydrological regimes and inevitably cause changes to groundwater level, which can result in the ecological degradation of coastal wetlands. Decreasing the groundwater level by the construction of drainage canals is an approach that has been widely used to control levels of root zone soil salinity as well as to protect freshwater wetlands or to expand agricultural land area in coastal wetlands. In this study, we assessed the influences of different drainage canal designs on the groundwater level using the Visual MODFLOW (VMOD) interface. We also provided an optimized drainage canal design suitable for the Yellow River Delta (YRD). Results showed that: (i) the groundwater level decreased in areas close to drainage canals, while only negligible effects were found on the groundwater level in areas with no drainage canals; (ii) the influence of drainage canals on the groundwater level decreased as distance increased; and (iii) a drainage canal network design of a depth of 5 m, with canal configuration of north-south direction and canal spacing of 1000 m was more effective in reducing the groundwater level in the study area. Our findings indicated that changes in groundwater level by the construction of drainage canals could help in our understanding of how groundwater influences freshwater wetlands and also aid in maintaining the integrity of coastal wetlands.

Evaluation of the Self-Adjusting File system (SAF) for the instrumentation of primary molar root canals: a micro-computed tomographic study.

PubMed

Kaya, E; Elbay, M; Yiğit, D

2017-06-01

The Self-Adjusting File (SAF) system has been recommended for use in permanent teeth since it offers more conservative and effective root-canal preparation when compared to traditional rotary systems. However, no study had evaluated the usage of SAF in primary teeth. The aim of this study was to evaluate and compare the use of SAF, K file (manual instrumentation) and Profile (traditional rotary instrumentation) systems for primary-tooth root-canal preparation in terms of instrumentation time and amounts of dentin removed using micro-computed tomography (μCT) technology. Study Design: The study was conducted with 60 human primary mandibular second molar teeth divided into 3 groups according to instrumentation technique: Group I: SAF (n=20); Group II: K file (n=20); Group III; Profile (n=20). Teeth were embedded in acrylic blocks and scanned with a μCT scanner prior to instrumentation. All distal root canals were prepared up to size 30 for K file,.04/30 for Profile and 2 mm thickness, size 25 for SAF; instrumentation time was recorded for each tooth, and a second μCT scan was performed after instrumentation was complete. Amounts of dentin removed were measured using the three-dimensional images by calculating the difference in root-canal volume before and after preparation. Data was statistically analysed using the Kolmogorov-Smirnov and Kruskal-Wallis tests. Manual instrumentation (K file) resulted in significantly more dentin removal when compared to rotary instrumentation (Profile and SAF), while the SAF system generated significantly less dentin removal than both manual instrumentation (K file) and traditional rotary instrumentation (Profile) (p<.05). Instrumentation time was significantly greater with manual instrumentation when compared to rotary instrumentation (p<.05), whereas instrumentation time did not differ significantly between the Profile and SAF systems. Within the experimental conditions of the present study, the SAF seems as a useful

Use of Ultrasonic Energy in Assessing Microbial Contamination on Surfaces

PubMed Central

Puleo, John R.; Favero, Martin S.; Petersen, Norman J.

1967-01-01

Ultrasonic tanks were evaluated for their ability to remove viable microorganisms from various surfaces for subsequent enumeration. Test surfaces were polished stainless steel, smooth glass, frosted glass, and electronic components. The position of contaminated surfaces in relation to the ultrasonic energy source, distance of the ultrasonic source from the test surfaces, and temperature of the rinse fluid were some of the factors which influenced recovery. Experimental systems included both naturally occurring microbial contamination and artificial contamination with spores of Bacillus subtilis var. niger. The results showed that ultrasonic energy was more reliable and efficient than mechanical agitation for recovering surface contaminants. Conditions which increased the number and percentage of microorganisms recovered by ultrasonic energy were: using a cold rinse fluid, placing the sample bottle on the bottom of the ultrasonic tank, and facing the contaminated surfaces toward the energy source. It was also demonstrated that ultrasonic energy could be effectively used for eluting microorganisms from cotton swabs. PMID:16349743

77 FR 42644 - Safety Zone; Canal Fest of the Tonawandas, Erie Canal, Tonawanda, NY

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-20

.... ACTION: Temporary final rule. SUMMARY: The Coast Guard is establishing a temporary safety zone on the... Canal during the Canal Fest of the Tonawandas Fireworks display. This temporary safety zone is necessary to protect spectators and vessels from the hazards associated with a fireworks display. DATES: This...

Comparison of Epson scanner quality for radiochromic film evaluation

PubMed Central

Alnawaf, Hani; Yu, Peter K.N.

2012-01-01

Epson Desktop scanners have been quoted as devices which match the characteristics required for the evaluation of radiation dose exposure by radiochromic films. Specifically, models such as the 10000XL have been used successfully for image analysis and are recommended by ISP for dosimetry purposes. This note investigates and compares the scanner characteristics of three Epson desktop scanner models including the Epson 10000XL, V700, and V330. Both of the latter are substantially cheaper models capable of A4 scanning. As the price variation between the V330 and the 10000XL is 20‐fold (based on Australian recommended retail price), cost savings by using the cheaper scanners may be warranted based on results. By a direct comparison of scanner uniformity and reproducibility we can evaluate the accuracy of these scanners for radiochromic film dosimetry. Results have shown that all three scanners can produce adequate scanner uniformity and reproducibility, with the inexpensive V330 producing a standard deviation variation across its landscape direction of 0.7% and 1.2% in the portrait direction (reflection mode). This is compared to the V700 in reflection mode of 0.25% and 0.5% for landscape and portrait directions, respectively, and 0.5% and 0.8% for the 10000XL. In transmission mode, the V700 is comparable in reproducibility to the 10000XL for portrait and landscape mode, whilst the V330 is only capable of scanning in the landscape direction and produces a standard deviation in this direction of 1.0% compared to 0.6% (V700) and 0.25% (10000XL). Results have shown that the V700 and 10000XL are comparable scanners in quality and accuracy with the 10000XL obviously capable of imaging over an A3 area as opposed to an A4 area for the V700. The V330 scanner produced slightly lower accuracy and quality with uncertainties approximately twice as much as the other scanners. However, the results show that the V330 is still an adequate scanner and could be used for radiation

Anatomical and morphological study of the subcoracoacromial canal.

PubMed

Le Reun, O; Lebhar, J; Mateos, F; Voisin, J L; Thomazeau, H; Ropars, M

2016-12-01

Many clinical anatomy studies have looked into how variations in the acromion, coracoacromial ligament (CAL) and subacromial space are associated with rotator cuff injuries. However, no study up to now had defined anatomically the fibro-osseous canal that confines the supraspinatus muscle in the subcoracoacromial space. Through an anatomical study of the scapula, we defined the bone-related parameters of this canal and its anatomical variations. This study on dry bones involved 71 scapulas. With standardised photographs in two orthogonal views (superior and lateral), the surface area of the subcoracoacromial canal and the anatomical parameters making up this canal were defined and measured using image analysis software. The primary analysis evaluated the anatomical parameters of the canal as a function of three canal surface area groups; the secondary analysis looked into how variations in the canal surface area were related to the type of acromion according to the Bigliani classification. Relative to glenoid width, the group with a large canal surface area (L) had significantly less lateral overhang of the acromion than the group with a small canal surface area (S), with ratios of 0.41±0.23 and 0.58±0.3, respectively (P=0.04). The mean length of the CAL was 46±8mm in the L group and 39±9mm in the S group (P=0.003). The coracoacromial arch angle was 38°±11° in the L group and 34°±9° in the S group; the canal surface area was smaller in specimens with a smaller coracoacromial arch angle (P=0.20). Apart from acromial morphology, there could be innate anatomical features of the scapula that predispose people to extrinsic lesions to the supraspinatus tendon (lateral overhang, coracoacromial arch angle) by reducing the subcoracoacromial canal's surface area. Anatomical descriptive study. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Endodontic management of middle mesial canal of the mandibular molar

PubMed Central

Sundaresh, K J; Srinivasan, Raghu; Mallikarjuna, Rachappa; Rajalbandi, Sandeep

2013-01-01

Thorough knowledge of root canal morphology and unusual anatomy of the tooth is critical for successful endodontic treatment. Although the most common configuration is two roots and three root canals, mandibular molars might have many different combinations. In the literature, it is less described about three mesial canals and two distal canals in mandibular second molars, indicating a rare anatomical configuration. A case of unusual root canal morphology is presented to demonstrate anatomical variations in mandibular molars. Endodontic therapy was performed in a mandibular second molar with five separate canals, three mesial and two distal. This report points out the importance of looking for additional canals and unusual canal morphology, because knowledge of their existence might occasionally enable clinicians to treat a case successfully that otherwise might have ended in failure. In conclusion, every attempt should be made to find and treat all root canals of a tooth. PMID:23349182

21 CFR 892.1330 - Nuclear whole body scanner.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Nuclear whole body scanner. 892.1330 Section 892...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1330 Nuclear whole body scanner. (a) Identification. A nuclear whole body scanner is a device intended to measure and image the distribution of...

21 CFR 892.1330 - Nuclear whole body scanner.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Nuclear whole body scanner. 892.1330 Section 892...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1330 Nuclear whole body scanner. (a) Identification. A nuclear whole body scanner is a device intended to measure and image the distribution of...

Morphological assessment of the mandibular canal trajectory in edentate subjects.