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Sample records for canal study nuclear

  1. Radiological safety research for nuclear excavation projects - Interoceanic canal studies

    International Nuclear Information System (INIS)

    The general radiological problems encountered in nuclear cratering and nuclear excavation projects are discussed. Procedures for assessing radiological problems in such projects are outlined. Included in the discussions are source term, meteorology, fallout prediction and ecological factors. Continuing research requirements as well as pre- and post-excavation studies are important considerations. The procedures followed in the current interoceanic canal feasibility studies provide examples of radiological safety problems, current solutions and needed research. (author)

  2. Optic Canal: Microanatomic Study

    OpenAIRE

    Slavin, Konstantin V.; Dujovny, Manuel; Soeira, Gelson; James I Ausman

    1994-01-01

    The microsurgical anatomy of the optic canal was defined on 20 cadaveric specimens. Anatomic parameters of the optic canal, optic nerve, ophthalmic artery, and adjacent structures were measured, and relations of these structures were noted. Five variants of the course of the ophthalmic artery relative to the optic nerve in the optic canal were found. Various aspects of microsurgery of the optic canal are discussed in relation to anatomic findings.

  3. Status of the interoceanic canal study

    International Nuclear Information System (INIS)

    The studies of Atlantic-Pacific Interoceanic Sea-Level Canal Study Commission are are not as yet completed, although there is no reason at this time to doubt that the 1 December 1970 deadline for the Commission's final report will be met. Since it has not been published, I am unable to pass on to you any of its conclusions; they simply do not exist today. And it would be improper for me to reveal the substance of the Commission's deliberations to date or to speculate upon what their outcome may be. But many elements of the work being conducted under my supervision - The Engineering Feasibility Study - are already in the public domain. It is to them that my remarks here are addressed. Of the six basic routes we have considered in our studies for possible sea-level canal alinements, four could involve nuclear excavating techniques. The so-called nuclear alternatives are Route 8 along the Nicaragua-Costa Rica border, Route 17 across the Darien Isthmus of Panama, Route 23 crossing the Panama-Colombia border and Route 25 across the western tip of Colombia. The conventionally excavated routes are Route 10 west of the Panama Canal Zone and Route 14 along the alinement of the present canal. The engineering studies examine from a technical standpoint the feasibility of constructing these routes and estimate their costs. To accomplish this we have made conceptual designs for canals capable of transiting at least 40,000 vessels annually (and possibly several times that many) and of accommodating ships of up to 250,000 dwt in size. Thus, in terms of basic requirements, all alternatives - conventional and nuclear - have been made comparable. Beginning with the northernmost route, let us now consider the four nuclear alternatives. Route 8 is 137 miles in length. Its maximum elevations are slightly less than 800 feet in the Continental Divide and about 400 feet through the so-called Eastern Divide. The rock to be excavated is primarily volcanic tuff. It is readily apparent that

  4. Radiological Review Studies On Ismailia Canal Ecology

    International Nuclear Information System (INIS)

    The present work is a brief review of pr-studies carried out on Ismailia Canal, Egypt, water ecosystem. Ismailia Canal water body is a bicarbonate stream with slight seasonal variations in its water chemical constituents. The canal water pH in all the stream locations are below 8.3 with low suspended matter(SM) content (22-33 mg.l-1). The mineralogical analysis of the canal bottom sediments consist mainly of quartz, smectite and kaolinite minerals. The γ- spectroscopic identification showed traces of naturally occurring radio nuclides (238U, 232Th and 40K). The average activity level of the dry samples ranged from 12 to 89 Bq.Kg-1 for the detected natural radio nuclides. Some parameters affected the sorption behaviour of radio nuclides on suspended matters and bottom sediments; such as solution pH, SM concentration, sediment grain size, carrier concentration and competing ions were studied. The reaction rates were investigated for each radionuclide studied. The distribution of the studied radio nuclides, between the liquid phase and the sediments phase was investigated, for both flowing and static systems. For both flowing and non-flowing (static), the depth penetration of the studied radio nuclides within the bottom sediment layers were found to vary from one radionuclide to the other. The total capacities of bottom sediments and the suspended matter were found to be low. As Ismailia Canal is an important source of water for public domestic uses, irrigation animals and the aquatic species; these situations have led to state that it is not recommended to release any liquid radioactive wastes to this canal. Furthermore, periodical radiometric analysis for the canal water and its components should be carried out.

  5. Computed tomography of the thoracic canal. Experimental and clinical studies

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, S. (Yamaguchi Univ., Ube (Japan). School of Medicine)

    1981-05-01

    Under the adequate CT condition, thoracic canal was studied in twelve normal cases, nine cases of cervical myelopathy with developmental cervical canal stenosis and four cases of thoracic myelopathy with ossification of thoracic yellow ligament. The results were as follows. 1) The adequate condition for delineation of thoracic canal seemed to be nearly 400 EMI units in window width and 150 in level. Scanning angle was permitted within about 10/sup 0/. Bony thoracic canal was well scanned at the center of vertebral body. 2) The configulation of the normal thoracic canal was oval at Th/sub 1/, Th/sub 2/ levels and round at Th/sub 3/-Th/sub 10/ and large oval at Th/sub 11/, Th/sub 12/. The sagittal diameter was almost fixed at each level and the transverse diameter was large at upper and lower levels and small at middle levels. 3) Thoracic canal was narrowed in the cases of cervical myelopathy with developmental cervical canal stenosis especially in sagittal diameter, but not narrowed in transverse diameter. Three of four cases who had myelopathy with ossification of thoracic yellow ligament had narrow canals. 4) There was a good relation between sagittal diameter of cervical canal and thoracic canal. 5) There was a good relation between sagittal diameter of thoracic canal measured by conventional radiographs (Hattori's method) and CT scans. The author thinks that Hattori's method is useful to diagnose the thoracic canal stenosis.

  6. Excavation of a Qattara Canal in Egypt: two-dimensional nuclear cratering calculations

    International Nuclear Information System (INIS)

    A series of single-charge nuclear cratering calculations were performed. Results from these calculations are being used in a study of the technical feasibility of the Qattara Project. The project would use nuclear explosives with yields ranging between about 200 and 1750 kilotons to excavate a canal about 73 km long connecting the Mediterranean Sea with the below sea-level Qattara Depression in northwestern Egypt. Computer simulations of explosive excavations were carried out at four locations near the proposed Qattara alignment. Holes were drilled in Egypt at these locations to depths of 372, 514, 632, and 701 m, respectively, to provide geophysical information needed to properly characterize each site for computer calculations. The calculated results for ground motion, particle velocity, and crater dimensions for these nuclear excavations are presented

  7. Nuclear magnetic imaging for MTRA. Spinal canal and spinal cord

    International Nuclear Information System (INIS)

    The booklet covers the following topics: (1) Clinical indications for NMR imaging of spinal cord and spinal canal; (2) Methodic requirements: magnets and coils, image processing, contrast media: (3) Examination technology: examination conditions, sequences, examination protocols; (4) Disease pattern and indications: diseases of the myelin, the spinal nerves and the spinal canal (infections, tumors, injuries, ischemia and bleedings, malformations); diseases of the spinal cord and the intervertebral disks (degenerative changes, infections, injuries, tumors, malformations).

  8. Model of Hydrologic Redistribution of Radionuclides around Nuclear-Excavated Sea-Level Canals

    International Nuclear Information System (INIS)

    As part of the bio environmental and radiological-safety feasibility studies for nuclear excavation of a sea-level canal in Central America, a model was developed to estimate the rate at which excavation-produced radionuclides are redistributed by natural hydrologic processes, The model can be used to estimate the amount of a specific radionuclide available for interaction with plant, animal, or man. The model was formulated for two distinct regions: in the canal channel itself and the region away from the canal where dust and fine particles are deposited as wind-distributed fallout. Redistribution within the canal channel can be handled by estimating flow through rubble from the analogous linear heat flow problem. For the fallout zone portion of the model, redistribution is controlled by the initial removal by rainwater leaching: for jungle areas, erosion by overland flow is negligible as most run-off is confined to a highly permeable interflow layer at the surface. The existence of the interflow layer has also eliminated the need to examine the redistribution of each storm; average rainfall values are sufficient to determine the rate at which a radionuclide is leached from the fallout. The amount of radionuclide which is removed with rainfall is represented by the simple distribution coefficient (Kd). Once the nuclide is dissolved, its rate of entry into the groundwater reservoir and into the stream can be determined from soil density and porosity, longterm infiltration rates, and some pre-excavation hydrologie data. This model has been applied to two of the proposed canal sites in Panama and Colombia, The effects of distribution coefficient values on redistribution were analysed. For the fallout zone, an increase by a factor of ten in Kde decreases initial concentration in river water at a use point by a factor of ten. For radionuclides with distribution coefficients higher than 102, concentration of the radionuclide in river water continues at a near constant

  9. Model of hydrologic redistribution of radionuclides around nuclear-excavated sea-level canals

    International Nuclear Information System (INIS)

    As part of the bioenvironmental and radiological-safety feasibility studies for nuclear excavation of a sea-level canal in Central America, a model was developed to estimate the rate at which excavation-produced radionuclides are redistributed by natural hydrologic processes. The model can be used to estimate the amount of a specific radionuclide available for interaction with plant, animal, or man. The model was formulated for two distinct regions: in the canal channel itself and the region away from the canal where dust and fine particles are deposited as wind-distributed fallout. Redistribution within the canal channel can be handled by estimating flow through rubble from the analogous linear heat flow problem. For the fallout zone portion of the model, redistribution is controlled by the initial removal by rainwater leaching: for jungle areas, erosion by overland flow is negligible as most run-off is confined to a highly permeable interflow layer at the surface. The existence of the interflow layer has also eliminated the need to examine the redistribution of each storm; average rainfall values are sufficient to determine the rate at which a radionuclide is leached from the fallout. The amount of radionuclide which is removed with rainfall is represented by the simple distribution coefficient (Kd). Once the nuclide is dissolved, its rate of entry into the groundwater reservoir and into the stream can be determined from soil density and porosity, long-term infiltration rates, and some pre-excavation hydrologic data. This model has been applied to two of the proposed canal sites in Panama and Colombia. The effects of distribution coefficient values on redistribution were analysed. For the fallout zone, an increase by a factor of ten in Kd decreases initial concentration in river water at a use point by a factor of ten. For radionuclides with distribution coefficients higher than 102, concentration of the radionuclide in river water continues at a near constant

  10. Canals in the Roof of the Pharynx :Anatomic Study and their Clinical Meaning

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    1 IntroductionThe palatovaginal canal and the vomerovaginal canal are small canals which connect the roof of the nasopharynx to the posterior wall of the pterygopalatine fossa. The pterygopalatine fossa represents a major pathway for spread of malignant tumors and infections. In most of the classic anatomy texts brief descriptions of the palatovaginal canal and the vomerovaginal canal are provided. There is still a scarcity of studies comparing the radiologic and microdissection findings~([1]). The aim of t...

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

    Directory of Open Access Journals (Sweden)

    Sushma Rathi

    2010-01-01

    Full Text Available 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.

  12. Interactions of radionuclides in water, particulates, and oysters in the discharge canal of a nuclear power plant. [Humboldt Bay reactor

    Energy Technology Data Exchange (ETDEWEB)

    Harrison, F.L.; Wong, K.M.; Heft, R.E.

    1976-08-19

    This study was designed to provide data for dynamic modeling of radioactive pollutants in marine ecosystems adjacent to nuclear power plants. The data are relevant to the dynamics of radionuclide transfer among seawater, suspended particulates, sediments, and biota. Gamma-emitting radionuclides (/sup 54/Mn, /sup 60/Co, /sup 65/Zn, and /sup 137/Cs) were followed in the water and particulates, as well as in oysters introduced into the discharge canal of the boiling water reactor of the Humboldt Bay Power Plant near Eureka, California. The liquid waste was introduced into the canal at irregular intervals and contained radionuclides at extremely low but variable concentrations. Radionuclides were determined in the oysters, water, and particulates after single releases (over about 6 hr) and over a long series of releases (18 months).

  13. MRI study on spinal canal content in Western Maharashtrian population

    Directory of Open Access Journals (Sweden)

    Khanapurkar SV, Kulkarni DO, Bahetee BH, Vahane MI

    2014-07-01

    Full Text Available The morphology of the spinal canal content has been studied since the invention of myelography. However, most studies have measured the diameters of the spinal cord only, not the size of the subarachnoid space. The present study complements the current data on the morphology of the spinal contents, and in particular, the spinal subarachnoid space, by analyzing MRI images. Objective: To study morphology of the dural sac, spinal cord & subarachnoid space using MRI. To define the inner geometrical dimensions of spinal canal content that confine the maneuver of an endoscope inserted in cervical spine. 3. To have comprehensive knowledge of the anatomy of cervical spinal canal. Method: Based on MRI images of the spine from 60 normal patients of age between 25-60 years, the dimensions of spinal cord, dural sac & subarachnoid space were measured at mid-vertebral & intervertebral level from C1-C7 vertebrae. The parameters measured were transverse, sagittal diameter of spinal cord & dural sac. The subarachnoid space was measured as anterior, posterior, right, left distance between spinal cord and dura mater. Results: It was found that at each selected transverse level, the subarachnoid space tends to be symmetrical on the right and left sides of the cord, and measures 3.38 mm on an average. However, the anterior and posterior segment, measured on the mid-sagittal plane are generally asymmetric & varies greatly in size ranging 1mm to 6mm with mean 2.57 of anterior & 2.59 of posterior. These measurements match those found in previous studies. The coefficient of variance for the dimensions of the subarachnoid space is as high as 36.16%, while that for the dimensions of the spinal cord (transverse & sagittal are11.08%&13.28%respectively. Conclusion: The findings presented here, expand our knowledge of morphology of spinal canal and show that a thecaloscope must be smaller than 3.38 mm in diameter.

  14. Comparative study of sealing ability of three root canal sealers

    Directory of Open Access Journals (Sweden)

    Khedmat S.

    2007-07-01

    Full Text Available Background and Aim: Complete obturation of the prepared root canal is an essential step in endodontic treatment. Combination of gutta-percha and a sealer is widely used in clinical practice for root canal obturation, thus microleakage studies on sealing properties of these materials constitute an important part of endodontic researches. The aim of this study was to evaluate the microleakage of three root canal sealers: Apexit, AH26 and Dorifill by electrochemical method.Materials and Methods: In this experimental study, 55 extracted human maxillary and mandibular cuspids were used. The coronal part of teeth were removed and the root canals were prepared using the step-back technique. The specimens were randomly divided into 3 groups of 17 samples each. Teeth in each group were filled with one of the sealers and gutta-percha by lateral condensation technique. 4 specimens served as positive and negative controls. An electrochemical method was used for evaluation of apical leakage with the electrical source potential of 10 V. Measurements of current flow through the test system were recorded every 72 hours. Data were analyzed by Kruskall Wallis and Mann Whitney tests. P<0.05 was considered as the level of significance.Results: All specimens of the three groups showed low initial leakage that increased during the test period. The mean leakage in Apexit group was higher than AH26 and Dorifill groups. The lowest mean leakage was related to Dorifill group. Although no statistically significant difference was observed between this sealer and AH26.Conclusion: The results of this study revealed that the best apical seal was obtained using Dorifill and AH26 sealers. The poorest result was observed in Apexit.

  15. A comparison of methods used in root canal sealability studies

    International Nuclear Information System (INIS)

    The purpose of the study was to compare several methods that have been used to assess marginal leakage of root canal fillings. Sixty-three extracted, single-rooted teeth were instrumented and filled in a standardized manner. Teeth were randomly divided into groups of twenty and exposed to solutions containing methylene blue dye, calcium-45, carbon-14-labeled urea, and iodine-125-labeled albumin for 48 hours to compare the degree of leakage indicated by each technique. Methylene blue dye was found to penetrate farther up the canal than any of the isotope tracers. Carbon-14-labeled urea penetrated farther than the calcium-45- or iodine-125-labeled albumin. The mean volume of solution penetrating the teeth was exceedingly small (0.0011 ml) and probably unimportant physiologically

  16. A comparison of methods used in root canal sealability studies

    Energy Technology Data Exchange (ETDEWEB)

    Matloff, I.R.; Jensen, J.R.; Singer, L.; Tabibi, A.

    1982-02-01

    The purpose of the study was to compare several methods that have been used to assess marginal leakage of root canal fillings. Sixty-three extracted, single-rooted teeth were instrumented and filled in a standardized manner. Teeth were randomly divided into groups of twenty and exposed to solutions containing methylene blue dye, calcium-45, carbon-14-labeled urea, and iodine-125-labeled albumin for 48 hours to compare the degree of leakage indicated by each technique. Methylene blue dye was found to penetrate farther up the canal than any of the isotope tracers. Carbon-14-labeled urea penetrated farther than the calcium-45- or iodine-125-labeled albumin. The mean volume of solution penetrating the teeth was exceedingly small (0.0011 ml) and probably unimportant physiologically.

  17. COMPARATIVE STUDY OF CHELATION VALUE OF SEVENTEEN PERCENT SELF DEVELOPED AND COMMERCIALLY AVAILABLE ROOT CANAL LUBRICANTS

    Directory of Open Access Journals (Sweden)

    Ingale Satish Dinkarrao

    2013-06-01

    Full Text Available The main objective of this study is to compare chelation values of 17% self developed & commercially available root canal Lubricants or dental chelating gels as well as to see whether their performance depends on the chelation value or not. The Chelating agent bounds Ca2+ ions of the smear layer & the extent of chelate formation between chelating agent and metal ion is nothing but Chelation Value. Sodium carbonate indicator method is used for determinations of chelation value. Commercially available gel incorporated in this study was File Rite which has little bit higher chelation value. Self developed chelating gel or root canal lubricants have comparatively lower chelation value. Root canal lubricants having higher chelation value should perform better in shaping & cleaning of root canal better. However because of slight difference in chelation value of self developed & commercially available gel, no significant difference was found out as root canal lubricants, when applied in root canal for 5 minutes.

  18. The Dissolving Ability of Different Organic Solvents on Three Different Root Canal Sealers: In Vitro Study

    OpenAIRE

    2012-01-01

    Introduction The purpose of this in vitro study was to evaluate three common gutta-percha solvents’ effectiveness in dissolving three different types of root canal sealers. Materials and Methods The solubility of three different root canal sealers (AH Plus, Apexit Plus and Endoflas FS) was assessed in xylene, refined orange oil, tetrachloroethylene and distilled water (control). One-hundred twenty samples of root canal sealers were prepared and then divided into three equal groups (n=40). Eac...

  19. Cone-beam computed tomography study of root and canal morphology of mandibular premolars in a western Chinese population

    International Nuclear Information System (INIS)

    Traditional radiography is limited in its ability to give reliable information on the number and morphology of root canals. The application of cone-beam computed tomography (CBCT) provides a non-invasive three-dimensional confirmatory diagnosis as a complement to conventional radiography. The aim of this study was to evaluate the root and canal morphology of mandibular premolars in a western Chinese population using CBCT scanning. The sample included 149 CBCT images comprising 178 mandibular first premolars and 178 second premolars. The tooth position, number of roots and canals, and canal configuration according to Vertucci’s classification were recorded. The results showed that 98% of mandibular first premolars had one root and 2% had two roots; 87.1% had one canal, 11.2% had two canals and 0.6% had three canals. The prevalence of C-shaped canals was 1.1%. All mandibular second premolars had one root; 97.2% had one canal and 2.2% had two canals. The prevalence of C-shaped canals was 0.6%. The prevalence of multiple canals in mandibular first premolars was mainly of Type V, and mandibular second premolars had a low rate of canal variation in this western Chinese population. Root canal bifurcation occurred at the middle or apical third in most bicanal mandibular premolars. CBCT scanning can be used in the management of mandibular premolars with complex canal morphology

  20. A comparison between radiovisiography and clearing technique in the study of the root canal types

    Institute of Scientific and Technical Information of China (English)

    Daming Wu; Younong Wu

    2005-01-01

    Objective: To compare the radiovisiography (RVG) with the clearing technique using Kappa value in the study of the root canal types. Methods: One hundred recently extracted human maxillary first premolars were used. Standard periapical RVG images were taken from a buccolingual and mesiodistal direction. The specimens were then accessed, injected with ink, demineralized,dehydrated, and finally were cleared. The RVG images and the transparent teeth were examined by a trained endodontist, and the date of root canal types following Wu's classification was collected. Results: The reliability of RVG was high for studies on simple root canals,but was poor for the studies on the multiple root canals. The Kappa value between the two techniques was 0.3793, indicating the agreement was poor. Conclusion: It is concluded that the limited value of RVG alone when studying certain aspect of the root canal system. The resolution of the RVG system should be enhanced.

  1. The fit of tapered posts in root canals luted with zinc phosphate cement : A histological study

    NARCIS (Netherlands)

    Schmage, P; Ozcan, M; McMullan-Vogel, C; Nergiz, [No Value; Özcan, Mutlu; Nergiza, Ibrahim

    2005-01-01

    Objectives. Stress transmission to the root through passive fitting dental posts is partly influenced by the thickness of the cement layer between the post and the prepared root canal surface as well as the fit of the post in the root canal. The objective of this study was to compare the cement gap

  2. The fit of tapered posts in root canals luted with zinc phosphate cement: A histological study

    NARCIS (Netherlands)

    Schmage, P.; Ozcan, M.; McMullan-Vogel, C.; Nergiz, I.

    2005-01-01

    Objectives. Stress transmission to the root through passive fitting dental posts is partly influenced by the thickness of the cement layer between the post and the prepared root canal surface as well as the fit of the post in the root canal. The objective of this study was to compare the cement gap

  3. Comparative Study the Physical Properties of Flow, Solubility and Disintegration of Some Root Canal Sealers

    Directory of Open Access Journals (Sweden)

    Mirian Fátima Zacarro SCELZA

    2006-09-01

    Full Text Available Objective: The aim of this study was to evaluate comparatively the physical properties of solubility, disintegration and flow of some root canal sealers: SEALAPEX™, PULP CANAL SEALER™, TUBLISEAL™, AH PLUS™, AH 26™, TOP SEAL™, SEALER PLUS™, SEALER 26™ and ENDOFILL™. Method: Methodology used was according ISO 6786 which test the physicochemical properties using five proof specimens for each test. Results: In terms of solubility, the root canal sealers analyzed have been classified in the following decreasing order: ENDOFILL™, SEALAPEX™, PULP CANAL SEALER™, AH 26™, TUBLISEAL™, SEALER PLUS™, AH PLUS™, TOP SEAL™ and SEALER 26™, where a statistically significant difference was found at a 1% level. Between TOP SEAL™ and SEALER™ 26 root canal sealers there was no statistically significant difference. None of the sealers above have shown disintegration. Regarding flow, the root canal sealers in the study have been classified in the following decreasing order: TUBLISEAL™ root canal sealer, followed by ENDOFILL™, SEALAPEX™, PULP CANAL SEALER™, AH PLUS™, TOP SEAL™, AH 26™, SEALER 26™ and SEALER PLUS™, where a statistically significant difference was found at a 1% level. Conclusion: The solubility, only the SEALAPEX™ and ENDOFILL™ have shown a limit above determined by ISO 6786.

  4. Garigliano Nuclear Power Plant, Italy: Decontamination and Rearranging of Reactor Canal and Spent Fuel Pool

    International Nuclear Information System (INIS)

    Garigliano nuclear power plant was a 506 MW(th), first generation, dual cycle BWR. It started operation in 1964 and finally shut down in 1978, following the discovery of serious damage to a secondary steam generator. This section describes decontamination activities carried out in 1991–1993 in preparation for safe enclosure of Garigliano reactor building.1 Activities were carried out after completion of spent fuel transport off-site (1985–1987). A schematic of the spent fuel pool and adjacent areas is provided. Decontamination activities included the following: (a) Agitation and resuspension of pool sediments using water jets and water filtration. (b) Lowering of water level and parallel decontamination of pool walls with high pressure water jets of approximately 700 kg/cm2. (c) Removal, decontamination and interim storage on gangways of equipment located on the pool south-east wall. (d) Removal, decontamination and storage of the fuel transport container platform. (e) Removal of four fuel racks to their pool wall bearings, decontamination and transfer to the fresh fuel room. (f) Decontamination of the vessel head platform, removal from the reactor canal, brushing and coating to allow preservation and fixing of loose contamination. Eventually, this component was placed back in the reactor canal. (g) Construction in the reactor canal of an interim structure supporting fuel racks. At the completion of the work, this structure was dismounted, decontaminated and removed. (h) Removal of fuel racks (five at a time) to their pool wall bearings, decontamination and interim storage in the reactor canal. (i) Gradual lowering of the pool water level to some 50 cm from the pool floor and parallel decontamination of fixed structures and walls. (j) Discovery by visual inspection and radiological checks, of activated components on the floor of the pool. Retrieval of all this material, segmentation as needed, temporary storage in containers and later transfer to the high

  5. Cone Beam Computed Tomography Study of Root and Canal Morphology of Maxillary first Molar in an Iranian Population

    OpenAIRE

    Faramarzi; Shokri; Shams; Vossoghi; Khoshbin

    2015-01-01

    Background The success of endodontic treatment depends on detection of all root canals so that they could be cleaned, shaped and obturated appropriately. To achieve this, it is essential to know root canals complexities such as the number of canals and types of each root canal, which are genetically determined. Besides, the highest failure rates occur in maxillary first molars. Objectives Therefore, the aim of this study was to in...

  6. A study of angle of mandibular canal and mental foramen on the panoramic radiograph

    International Nuclear Information System (INIS)

    To assessment the angle between mandibular canal and occlusal plane at each posterior tooth region and location of mental foramen on the panoramic radiographs. This study analysed 46 half-mandibles of panoramic radiographs. Inferior border of mandibular canal was traced. Occlusal plane was drawn from lingual cusp tip of the first premolar to distolingual cusp tip of the second molar. Perpendicular line from occlusal plane was drawn at each tooth region and then tangential lines were drawn from the crossing points at canal. The angle between occlusal plane and tangential line was measured. The location of mental foramen was also studied. According to the location of mental foramen, radiographs were divided into M (mesial) group and D (distal) group on the basis of the second premolar. and then inter-group analysis about mandibular canal angle was done. The angles of mandibular canals were -17.7 .deg. C, -9.5 .deg. C, 8.2 .deg. C, 22.3 .deg. C, and 39.2 .deg. C at first premolar, second premolar, first molar, second molar, and third molar, respectively. The commonest position of the mental foramen was distal to the second premolar. Inter-group comparison showed statistically significant difference at the second premolar and the first molar (p<0.001). The acknowledgement of mandibular canal angulation and location of mental foramen can help understanding the course of mandibular canal.

  7. A study of angle of mandibular canal and mental foramen on the panoramic radiograph

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hang Moon [Department of Oral and Maxillofacial Radiology and Oral Science Institute, College of Dentistry, Kangnung-Wonju National University, Kangnung (Korea, Republic of)

    2009-06-15

    To assessment the angle between mandibular canal and occlusal plane at each posterior tooth region and location of mental foramen on the panoramic radiographs. This study analysed 46 half-mandibles of panoramic radiographs. Inferior border of mandibular canal was traced. Occlusal plane was drawn from lingual cusp tip of the first premolar to distolingual cusp tip of the second molar. Perpendicular line from occlusal plane was drawn at each tooth region and then tangential lines were drawn from the crossing points at canal. The angle between occlusal plane and tangential line was measured. The location of mental foramen was also studied. According to the location of mental foramen, radiographs were divided into M (mesial) group and D (distal) group on the basis of the second premolar. and then inter-group analysis about mandibular canal angle was done. The angles of mandibular canals were -17.7 .deg. C, -9.5 .deg. C, 8.2 .deg. C, 22.3 .deg. C, and 39.2 .deg. C at first premolar, second premolar, first molar, second molar, and third molar, respectively. The commonest position of the mental foramen was distal to the second premolar. Inter-group comparison showed statistically significant difference at the second premolar and the first molar (p<0.001). The acknowledgement of mandibular canal angulation and location of mental foramen can help understanding the course of mandibular canal.

  8. Recognition of root canal orifices at a distance - a preliminary study of teledentistry.

    Science.gov (United States)

    Brüllmann, Dan; Schmidtmann, Irene; Warzecha, Katharina; d'Hoedt, Bernd

    2011-01-01

    The remote recognition of root canal orifices was tested on 50 images of endodontically accessed teeth acquired with an intra-oral camera. The images were stored on a laptop computer and were presented to 20 observers who marked the visible canal orifices using software which stored the canal locations in standard files. The marked positions were verified on histological slices. In 87% of the cases, the canal locations were marked correctly. Inter-observer reliability depended on the location of the reviewed root canal (kappa = 0.44-0.77). The detection rate was related to the professional experience of the observers. The maximum proportion of accurate detections was found for the observers with more than 10 years of professional experience. The minimum proportion of accurate detections, 79%, was by the observer with one year of experience. The results of the study suggest that remote recognition of root canals by experienced dentists can help younger colleagues in the detection of root canal orifices. PMID:21339303

  9. Root canal anatomy study of lower incisors by the clearing technique

    Directory of Open Access Journals (Sweden)

    Daniel GALAFASSI

    2007-05-01

    Full Text Available To succeed in the endodontic therapy, it’s a requisite to have fullknowledge of the inner root anatomy, as well as its variations. Thelower incisors are the tinniest teeth of the human arcade having a root strongly flattened to the mesio-distal way. This flattening is sometimes as big to split the root canal in two, one vestibular and another lingual.This study has utilized the clearing technique (method that allows to see through transparency the diverse root anatomy to accomplish its objective of analyzing the incidence of the canals present in the cervical third, middle and apical of the incisors’ roots of human lowers. For that purpose, 150 teeth have been obtained from the Teeth Bank of the Odontology Faculty of the University of Passo Fundo, on which the clearing technique and the injection of Naquin ink in the pulp cavity interior were applied, followed by the conservation in the methyl salicylate, allowing to three-dimensionally observe, through transparency, the internal anatomy of the root canal. The results have been analyzed by descriptive statistics, in which it was observed that 81,63% of the analyzed samples have presented one canal in the cervical third; 53,06% have two canals in the middle third and 71,42% have one canal in the apical third. With this it can be concluded that there is a major incidence of the root canal bifurcation in the middle third of the root in relation to the cervical and apical.

  10. 76 FR 55732 - Public Listening Sessions Regarding the Maritime Administration's Panama Canal Expansion Study...

    Science.gov (United States)

    2011-09-08

    ... Maritime Administration Public Listening Sessions Regarding the Maritime Administration's Panama Canal Expansion Study and the America's Marine Highway Program AGENCY: Maritime Administration, DOT. ACTION: Notice. SUMMARY: The purpose of this notice is to announce a series of public listening sessions...

  11. Comparison of antimicrobial substantivity of root canal irrigants in instrumented root canals up to 72 h: An in vitro study

    OpenAIRE

    M N Shahani; Subba Reddy, V. V.

    2011-01-01

    Disinfection of the root canal system is one of the primary aims of root canal treatment. This can be achieved through the use of various antimicrobial agents in the form of irrigants and medicaments. The antimicrobial substantivity of 2% chlorhexidine gluconate, 1% povidone iodine, 2.5% hydrogen peroxide followed by 2% sodium hypochlorite, and 2% sodium hypochlorite alone as irrigants was assessed in instrumented root canals. 2% chlorhexidine showed antimicrobial substantivity lasting up to ...

  12. Roentgenographic study of two root canal incidence in mandibular first premolars

    International Nuclear Information System (INIS)

    The root canal number in 1,632 mandibular first premolars were studied by roentgenograms taken from mesiodistal direction. A second canal exists in at least 27.08 per cent of all the teeth examined. Two comprehensive tables were taken: one was prepared to summarize all the data which were classified by root morphology. The second compares the results taken by other authors. (M.A.C.)

  13. Root canal morphology of mandibular first premolar in a Gujarati population - An in vitro study

    Directory of Open Access Journals (Sweden)

    Atul Jain

    2011-01-01

    Full Text Available Background: Knowledge about root canal morphology and its frequent variations can exert considerable influence on the success of endodontic treatment. The aim of this study was to survey the root canal morphology of mandibular first premolar teeth in a Gujarati population by decalcification and clearing technique. Methods : One hundred thirty eight extracted mandibular first premolar teeth were collected from a Gujarati population. After decalcifying and clearing, the teeth were examined for tooth length, number of cusps and roots, number and shape of canal orifices and canal types. Results: The average length of mandibular first premolar teeth was 21.2 mm. All the teeth had 2 cusps. One hundred thirty four teeth (97.1% had one root, and just 4 teeth (2.89% had two roots. Mesial invagination of root was found in 21 teeth (15.21%. One canal orifice was found in 122 teeth (88.4% and two canal orifices in 16 teeth (11.59%. Shape of orifices was found to be round in 46 teeth (33.33%, oval in 72 teeth (52.17% and flattened ribbion in 20 teeth (14.49%. According to Vertucci′s classification, Type I canal system was found in 93 teeth (67.39%, Types II,III,IV,V,and VI in 11 teeth (7.97%, 5 teeth (3.62%, 4 teeth (2.89%, 24 teeth (17.39%, and 1 tooth (0.72% respectively. Conclusion: Mandibular first premolar teeth were mostly found to have one root and Type I canal system.

  14. Study on the law of Unsteady Phreatic Water Seepage Near by Canals

    Science.gov (United States)

    Cao, P.; Tao, Y.

    2013-12-01

    Unsteady phreatic water seepage nearby canals is a classical problem in seepage mechanics. One of the classic solutions is use Boussinesq equation based on the assumption of Dupuit as the control equation, combine with the boundary conditions and initial conditions to solve it. The method can only used in the case of small hydraulic gradient. The paper take the unsteady phreatic water seepage nearby canals has larger hydraulic gradient as the research object, and establish a model suitable for this condition. Based on the first linearized Boussinesq equation and Laplace transform, the analytical solution of the model is obtained by flow integral and verified by sand tank experiment. The results showed that the free surface nearby canals is "parabolic" form changes to the "asymptotic" form when the canals water level rises. New solution is more realistic and calculate error of the original solution is larger at the beginning of canals water level variation. The law of unsteady phreatic water seepage nearby canals needs further study.

  15. A STUDY OF ROOT CANAL MORPHOLOGY OF Cebus apella TEETH ESTUDO ANATÔMICO DO CANAL RADICULAR DE DENTES DE Cebus apella

    Directory of Open Access Journals (Sweden)

    Priscilla Rocha Afonso

    2008-12-01

    Full Text Available Realizou-se um estudo anatômico em dentes do Cebus apella, para análise da anatomia interna do canal radicular dessa espécie, normatizando seu uso como modelo experimental. Utilizaram-se doze animais adultos. Após a remoção do tecido orgânico, os dentes foram removidos, seccionados e fotografados, sendo analisados com um estereomicroscópio. Os resultados mostraram que os dentes apresentaram características semelhantes às dos seres humanos, mas com algumas peculiaridades, tais como: a anatomia do canal radicular variou de oval para circular; nos caninos inferiores, os canais são semelhantes a um rim, o que reflete o contorno externo da raiz; nos molares superiores, os canais mesiobucal e distobucal são ovais, seguindo o contorno geral do dente. Os autores concluem que esta espécie pode ser utilizada como modelo em pesquisas odontológicas, principalmente em estudos do tratamento do sistema de canal radicular.

    PALAVRAS-CHAVES: Anatomia, dentes, Cebus apella. An anatomic study of Cebus apella root teeth was performed to analyze the internal anatomy of permanent dentition, normalizing its use as experimental model endodontic research. Twelve adult animals were used in this study. After the removal of the organic tissue, the all teeth were removed, sectioned, analyzed and photographed with a stereomicroscope. The results showed that the anatomy of root canal of this species are similar to human dental anatomy, considering the shape, pathway and number of canals, but with some peculiarities, such as: the root canal anatomy varied from oval to circular; in the lower canines, the canals are resembled a kidney, reflecting the outside contour of the root; in the upper molars, the mesiobuccal and distobuccal canals are oval, following the general contour of the tooth. The authors conclude that this primate can be applied as models for study of root canal treatment in human beings, in special the upper central and lateral incisors

  16. Comparison of antimicrobial substantivity of root canal irrigants in instrumented root canals up to 72 h: An in vitro study

    Directory of Open Access Journals (Sweden)

    M N Shahani

    2011-01-01

    Full Text Available Disinfection of the root canal system is one of the primary aims of root canal treatment. This can be achieved through the use of various antimicrobial agents in the form of irrigants and medicaments. The antimicrobial substantivity of 2% chlorhexidine gluconate, 1% povidone iodine, 2.5% hydrogen peroxide followed by 2% sodium hypochlorite, and 2% sodium hypochlorite alone as irrigants was assessed in instrumented root canals. 2% chlorhexidine showed antimicrobial substantivity lasting up to 72 h, followed by 1% povidone iodine, and 2% sodium hypochlorite. Thus 2% chlorhexidine should be used as a final rinse irrigant in endodontic treatment protocols.

  17. A study of mandibular foramen and mandibular canal using orthopantomograms

    International Nuclear Information System (INIS)

    The mandibular canal must be considered carefully during surgical treatment, especially surgical extraction of the impacted tooth and intraosseous implant because it contains the important inferior alveolar nerve and vessel. Th e author investigated the curvature of the mandibular canal, the positional frequency of mandibular foramen to the occlusal plane and gonial angle and the positional frequency of the mental foramen to the tooth site using orthopantomorgrams. The materials considered of 295 orthopantomograms divided into seven groups ranging from the first decade to 6th decade. The results were as follows: 1. The position of mandibular foramen was most frequently below occlusal plane in Group I (78.6%) and Group II (71.2%) , above occlusal plane in Group III (63.0%), Group IV (71.1%), Group V (57.6%), Group VI (76.7%) and Group VII (70.0%). 2. The curvature of mandibular canal was 142.82 .deg. in Group I, 142.09 .deg. in Group II, 139.34 .deg. in Group III, 141.48 .deg. in Group IV, 138.45 .deg. in Group V, 140.77 .deg. in Group VI and 143.89 .deg. in Group VII. 3. The gonial angle was 125.82 .deg. in Group I, 123.18 .deg. in Group II, 124.06 .deg. in Group III, 120.45 .deg. in Group IV, 121.12 .deg. in Group V, 121.63 .deg. in Group VI and 121.24 .deg. in Group VII. 4. The position of the mental foramen was most frequently below the apex of mandibular first premolar in Group I ( 57.2%), between the apex of mandibular first and second premolar in Group II (59.6%) and Group III (48.9%), and below the apex of mandibular second premolar in Group IV (39.2%), Group V (48.5%) Group VI (46.7%) and Group VII (56.4%).

  18. A study of mandibular foramen and mandibular canal using orthopantomograms

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hee Sang; Kim, Jhai Dhuck [Department of Dentistry, Graduate School, Chosun University, Kwangju (Korea, Republic of)

    1983-11-15

    The mandibular canal must be considered carefully during surgical treatment, especially surgical extraction of the impacted tooth and intraosseous implant because it contains the important inferior alveolar nerve and vessel. Th e author investigated the curvature of the mandibular canal, the positional frequency of mandibular foramen to the occlusal plane and gonial angle and the positional frequency of the mental foramen to the tooth site using orthopantomorgrams. The materials considered of 295 orthopantomograms divided into seven groups ranging from the first decade to 6th decade. The results were as follows: 1. The position of mandibular foramen was most frequently below occlusal plane in Group I (78.6%) and Group II (71.2%) , above occlusal plane in Group III (63.0%), Group IV (71.1%), Group V (57.6%), Group VI (76.7%) and Group VII (70.0%). 2. The curvature of mandibular canal was 142.82 .deg. in Group I, 142.09 .deg. in Group II, 139.34 .deg. in Group III, 141.48 .deg. in Group IV, 138.45 .deg. in Group V, 140.77 .deg. in Group VI and 143.89 .deg. in Group VII. 3. The gonial angle was 125.82 .deg. in Group I, 123.18 .deg. in Group II, 124.06 .deg. in Group III, 120.45 .deg. in Group IV, 121.12 .deg. in Group V, 121.63 .deg. in Group VI and 121.24 .deg. in Group VII. 4. The position of the mental foramen was most frequently below the apex of mandibular first premolar in Group I (57.2%), between the apex of mandibular first and second premolar in Group II (59.6%) and Group III (48.9%), and below the apex of mandibular second premolar in Group IV (39.2%), Group V (48.5%) Group VI (46.7%) and Group VII (56.4%).

  19. Study on congenital microtia and atresia after external canal plasty

    International Nuclear Information System (INIS)

    In treating congenital microtia and atresia, we conduct simultaneous external canal plasty, tympanoplasty, and auricle elevation with plastic surgeons about 6 months after auricleplasty by only plastic surgeons. The results are good both cosmetically and functionally. We report 13 cases in which hearing did not improve satisfactorily after surgery using postoperative high-resolution computed tomography (HRCT) of the temporal bone. Lateral healing was seen in 9 (69%), new bone proliferation in 3 (23%), malpositioning of a cartilage block in 2 (15%), and both lateral healing and malpositioning of a cartilage block in 1 (7.6%). (author)

  20. In Vitro Comparative Study of the Working Length Determination with Radiovisiography and Conventional Radiography in Dilacerated Canals

    Directory of Open Access Journals (Sweden)

    Ali Bagherpour

    2015-06-01

    Full Text Available Introduction: The aim of this study was to compare digital and conventional radiography in determining the working length of dilacerated canals.Methods: Thirty nine human extracted single-rooted teeth with root curvature more than 35 degrees were included in this study. After access preparation, a file was inserted into the canal and advanced until the file tip was visualized at the foramen. With measurement of the file length using a millimeter ruler, true canal length was determined for each canal. Then, teeth were mounted in acrylic blocks and canal length was estimated by using on-screen digital radiography with both 3- and 6-clicks measurement and from conventional radiography by conforming a preserved file on the image of the root canal.Results: There were no significant differences in measurement accuracy between the true canal length and conventional radiographic length, but there were significant difference between both digital radiographic techniques with true canal length. There was no significant correlation between root curvature and canal length estimation error of studied methods.Conclusion: In dilacerated canals, the accuracy of determination of working length by using conventional radiography is higher than digital radiography

  1. Cone Beam Computed Tomography Study of Root and Canal Morphology of Maxillary first Molar in an Iranian Population

    Directory of Open Access Journals (Sweden)

    Faramarzi

    2015-06-01

    Full Text Available Background The success of endodontic treatment depends on detection of all root canals so that they could be cleaned, shaped and obturated appropriately. To achieve this, it is essential to know root canals complexities such as the number of canals and types of each root canal, which are genetically determined. Besides, the highest failure rates occur in maxillary first molars. Objectives Therefore, the aim of this study was to investigate the root and canal morphology of maxillary first molars in an Iranian population using cone-beam computed tomography (CBCT. Materials and Methods In this study, images of 156 extracted maxillary first molars placed in the waxed blocks were produced using CBCT. Two professional investigators checked images by NNT software in New Tom 3G system. Axial view and cross section of 1 mm thickness were used. The number of roots, canals, each roots canal, MB1-MB2 orifice distances and canal types of the Vertucci classification were recorded. Finally, data was analyzed using SPSS16 software. Results We found 100% of cases with three separated roots, from which 69.23% had four canals including MB2 and 30.77% with three canals. 71.3% of mesiobuccal roots were two canals of type two Vertucci and 28.7% type 4 with the mean distance value of 2.55 ± 0.57 mm between MB1 and MB2 orifice. Conclusions Most extracted maxillary first molars were three rooted and four canals. CBCT has relatively high reproducibility and accuracy of distinguishing MB2 canal.

  2. Shaping ability of rotatory or reciprocating instruments in curved canals: a micro-computed tomographic study.

    Science.gov (United States)

    Jardine, Alexander Pompermayer; Rosa, Ricardo Abreu da; Santini, Manuela Favarin; Zaccara, Ivana Maria; Só, Marcus Vinicius Reis; Kopper, Patrícia Maria Poli

    2016-06-14

    This study aimed to compare apical transportation, centering ratio, and working time during root canal preparation with Wizard Navigator (WN), WaveOne (WO), or ProTaper Universal (PT) and to describe deformation and fracture of these instruments. Thirty-six mesiobuccal roots from maxillary molars were micro-computed tomography (micro-CT) scanned and then sorted into three groups (n = 12): Wizard Navigator (WN), WaveOne (WO), and ProTaper Universal (PT). The root canals were prepared using WN, WO, or PT; the time of each canal preparation was timed; and the specimens were micro-CT re-scanned. The instruments were submitted to scanning electron microscopy (SEM) before and after their use. The data on canal transportation at 1, 2, 3, 4 and 5 mm and preparation time were analyzed by the Kruskal-Wallis test, followed by the Mann-Whitney U test. The centering ratio was analyzed by ANOVA, followed by Tukey's test. Both instrument deformation and fracture were described. Apical transportation was similar among groups at 1, 2, 3 and 4 mm. The WO group showed higher canal transportation at 5mm than the other groups (p = 0.03). There was no significant difference in centering ratio among the groups. Preparation time in the WO group was significantly lower than in the other groups (p = 0.004). Small differences were observed in the surface area of all instruments. The WN, WO, and PT groups had a similar centering ratio without procedural errors or significant structural changes. At 5 mm from the apex, the WO group showed the largest canal transportation toward the furcation and root canal preparation was faster than in the WN and PT groups. PMID:27305517

  3. Nuclear magnetic imaging for MTRA. Spinal canal and spinal cord; Magnetresonanztomographie fuer MTRA. Spinalkanal und Wirbelsaeule

    Energy Technology Data Exchange (ETDEWEB)

    Fritzsch, Dominik; Hoffmann, Karl-Titus [Universitaetsklinikum Leipzig (Germany). Abt. fuer Neuroradiologie

    2011-07-01

    The booklet covers the following topics: (1) Clinical indications for NMR imaging of spinal cord and spinal canal; (2) Methodic requirements: magnets and coils, image processing, contrast media: (3) Examination technology: examination conditions, sequences, examination protocols; (4) Disease pattern and indications: diseases of the myelin, the spinal nerves and the spinal canal (infections, tumors, injuries, ischemia and bleedings, malformations); diseases of the spinal cord and the intervertebral disks (degenerative changes, infections, injuries, tumors, malformations).

  4. Root canal configuration of permanent maxillary first molar in Khasi population of Meghalaya: An in vitro study

    Directory of Open Access Journals (Sweden)

    Atool Chandra Bhuyan

    2014-01-01

    Full Text Available Aims and Objective: To investigate the root canal configuration of permanent maxillary first molar in Khasi population of Meghalaya. Material and Methods: Sixty (60 permanent maxillary first molars collected from patients of Khasi population of Meghalaya were studied using canal staining and clearing technique. Observations of the number of roots, root canal configuration, lateral canal, apical delta, and presence of the additional type of canals were made. Results: Based on Vertucci′s classification the different types of canal identified are: Mesiobuccal root, Type I (28.3%, Type II (28.3%, Type IV (30.0%, Type V (5.0%, Type VI (6.7%, and an additional type of canal (2-1-2-1-2; 1.7% were observed. The distobuccal root displayed Type I (95%, Type II (1.7%, Type V (3.3%. The most prevalent canal configuration in the palatal roots is Type I (98.3%, Type II (1.7%. Conclusion: In Khasi population of Meghalaya, the most prevalent root canal configuration in the mesiobuccal root is Type IV followed by Type I and Type II. MB2 canals are present in more than 65% cases. In palatal and distobuccal roots, Type I configuration is present in most cases. Racial divergence may be responsible for such variations.

  5. Root canal debris removal using different irrigating needles: An SEM study

    Directory of Open Access Journals (Sweden)

    Sheetal Ghivari

    2011-01-01

    Full Text Available Aim: This study was carried out to compare the efficacy of three irrigating needle designs in removal of debris from different parts of the root canal. Materials and Methods: Thirty human maxillary canines were prepared using HERO Shaper rotary system and irrigated with 1 ml of 5.25% sodium hypochlorite (NaOCl after each instrument change. Three 25-gauge irrigation needle designs - brush-covered Navi Tip FX (Group I, side-vented needle RC Twents (Group II and single-beveled (Group III irrigating needles - were tested for their efficiency in debris removal in three different parts of the root canal (n=10 canals per group. Following instrumentation, the roots were vertically sectioned and divided into coronal, middle and apical thirds for observation under scanning electron microscope (×200 magnification. Debris on the canal wall was evaluated by using a four-scale scoring system described by Paque and his co-workers. Results: The canals irrigated with brush-covered needle Navi Tip FX (Group I showed lower average debris score, indicating greater removal of debris in coronal third as compared to middle and apical thirds, whereas the canals irrigated with side-vented needle (Group II and single-beveled needle (Group III exhibited lower average score in the middle third than coronal and apical thirds. All the three needle designs exhibited higher debris score in apical third of the root canal. Tukey multiple comparisons test was applied at a significance level of P>0.05. A statistically significant difference (P<0.05 was observed in the debris removal in the coronal and middle thirds of root canals irrigated with brush-covered Navi Tip FX (Group I and side-vented (Group II needles, respectively, when compared with other needle design groups. Conclusion: Within the limitations of this study, it can be concluded that all the needle designs tested were effective in certain regions of the root canal with apical third uncleaned. Side-vented needle by

  6. Statistical Surface Recovery: A Study on Ear Canals

    DEFF Research Database (Denmark)

    Jensen, Rasmus Ramsbøl; Olesen, Oline Vinter; Paulsen, Rasmus Reinhold; van der Poel, Mike; Larsen, Rasmus

    We present a method for surface recovery in partial surface scans based on a statistical model. The framework is based on multivariate point prediction, where the distribution of the points are learned from an annotated data set. The training set consist of surfaces with dense correspondence that...... are Procrustes aligned. The average shape and point covariances can be estimated from this set. It is shown how missing data in a new given shape can be predicted using the learned statistics. The method is evaluated on a data set of 29 scans of ear canal impressions. By using a leave-one-out approach...... we reconstruct every scan and compute the point-wise prediction error. The evaluation is done for every point on the surface and for varying hole sizes. Compared to state-of-the art surface reconstruction algorithm, the presented methods gives very good prediction results....

  7. Root canal preparation of maxillary molars with the self-adjusting file: a micro-computed tomography study.

    OpenAIRE

    Peters, O A; Paqué, F

    2011-01-01

    INTRODUCTION: The aim of this study was to describe the canal shaping properties of a novel nickel-titanium instrument, the self-adjusting file (SAF), in maxillary molars. METHODS: Twenty maxillary molars were scanned by using micro-computed tomography at 20-μm resolution. Canals were shaped with the SAF, which was operated with continuous irrigation in a handpiece that provided an in-and-out vibrating movement. Changes in canal volumes, surface areas, and cross-sectional geometry ...

  8. Heavy metal pollution of the mid-canal of Kandy: an environmental case study from Sri Lanka

    Energy Technology Data Exchange (ETDEWEB)

    Dissanayake, C.B.; Niwas, J.M.; Weerasooriya, S.V.

    1987-02-01

    The mid-canal of Kandy, a 8-km effluent canal that runs through the city, collects massive quantities of domestic, municipal, and agricultural waste products. In this study, 37 samples from canal water and 13 from nearby drinking water wells were analyzed for their total Pb, Cd, V, Fe, and ferrous ion content. The following average values for the canal water were recorded: Pb, 269 micrograms/liter; Cd, 138 micrograms/liter; V, 18 micrograms/liter; total Fe, 4 mg/liter. These values indicate the relative levels of metal input from the effluent sources of the city of Kandy, the second largest city in Sri Lanka. The analysis of water from drinking wells near the canal showed high concentrations of metals, in some cases exceeding the maximum tolerance limits as recommended by WHO. The environmental impact of polluted city canals running through densely populated cities, particularly in developing countries, can assume serious proportions.

  9. Anatomical and Morphological Characterization of the Nasopalatine Canal: A Cone-Beam Computed Tomography Study.

    Science.gov (United States)

    Rodricks, D; Gupta, A; Phulambrikar, T; Singh, S K; Sharma, B K; Agrawal, P

    2016-04-01

    The anterior maxilla, also called pre-maxilla, is an area frequently requiring surgical interventions. Rehabilitation of this area remains a complex restorative challenge. The most prominent anatomical structure within the anterior maxilla is the Nasopalatine Canal. Thorough knowledge about this anatomical structure plays an important role in the successful outcomes of surgical procedures. This retrospective study was done to evaluate the anatomy and morphology of the Nasopalatine Canal using cone-beam computed tomography (CBCT). The study included 125 subjects aged between 15 and 78 years who were divided into the following 5 groups: i) 15-30 years, ii) 30-45 years, iii) 45-60 years, iv) 60-75 years, v) ≥75 years in the Department of Oral Medicine & Radiology, Sri Aurobindo College of Dentistry, Indore, Madhya Pradesh, India from January 2012 to January 2015. Cone-beam computed tomography (CBCT) was performed using a standard exposure and patient positioning protocol. The data of the CBCT images were sliced in three dimensions. Image planes on the three axes (X, Y, and Z) were sequentially analyzed for the location, morphology and dimensions of the Nasopalatine Canal. The correlation of age and gender with all the variables were evaluated. ANOVA and Z-test was used. P value <0.05 was considered statistically significant. Males and females showed significant differences in the length of the canal and anterior bone width in the sagittal sections. Inverted L was identified as a new dimension to the morphological shape of Nasopalatine Canal in central Madhya Pradesh population. The present study highlighted important variability observed in the anatomy and morphology of the Nasopalatine Canal. PMID:27277370

  10. Antimicrobial Activity of Three Root Canal Irrigants on Enterococcus Faecalis: An in Vitro Study

    OpenAIRE

    Ahangari, Zohreh; Samiee, Mohammad; Yolmeh, Mohammad Amin; Eslami, Gita

    2008-01-01

    INTRODUCTION: The aim of this study was to compare the antimicrobial effects of 2.5% Sodium hypochlorite (NaOCl), 2% Chlorhexidine Gluconate (CHX) and BioPure MTAD (MTAD) on Enterococcus (E) faecalis-contaminated root canals of human extracted teeth. MATERIALS AND METHODS: Seventy human intact extracted single-rooted teeth with straight root canal randomly divided into 5 groups: positive control (n=5), negative control (n=5), 2.5% NaOCl (n=20), 2% CHX (n=20), and MTAD (n=20). Each tooth was i...

  11. Root and canal symmetry in the mandibular anterior teeth of patients attending a dental clinic: CBCT study

    Directory of Open Access Journals (Sweden)

    Guven KAYAOGLU

    2015-01-01

    Full Text Available The aims of this study were to evaluate the number of roots/root canals in the mandibular anterior teeth of a Turkish population, to assess the relationship between gender or age and the frequency of two canals in a single root, and to determine the symmetry in root/root canal numbers between contralateral sides among patients. Cone-beam computed tomography images (n = 1128; 6253 teeth taken at the Department of Dentomaxillofacial Radiology of the Faculty of Dentistry of Gazi University were examined by three observers and a supervisor, all of whom were blinded to patient gender and age. Axial, sagittal, and cross-sectional slices with a thickness of 1 mm were used. Numbers of roots and canals for each type of tooth were recorded. Most teeth had a single root and single root canal. Roots with two canals were more frequent in the incisors (14.9%, 17.2%, and 6.1% of the central incisors, lateral incisors, and canines, respectively. Teeth with two roots were more frequent in the canines (3.1%vs. 0% or 0.1%. Females more often had canines with double root canals (p < 0.001. When at least one tooth had two root canals, bilateral symmetry between contralateral teeth was found in 45.0%, 29.0%, and 28.0% of cases for central incisors, lateral incisors, and canines, respectively. Patients older than 56 years had fewer teeth with double root canals (p ≤ 0.001. A small proportion of the mandibular anterior teeth had two roots or root canals. Double root canals were mostly unilateral. Age and gender were associated with the number of root canals.

  12. Study of seepage losses from irrigation canals using radioactive tracer technique

    International Nuclear Information System (INIS)

    wetted area of the canal. The radiotracer (/sup 99m/Tc) having very short half-life (6 hrs) poses no health hazards as it decays in one day after traveling a very short distance, at the most a few meters. A very small quantity of the tracer required for a test can be met from the leftover activity of /sup 99m/ Tc imported for medical centers. However ECNEC has approved a project produce. /sup 99m/Tc locally at PINSTECH which will ensure its availability at competitive cost. In this study it has been proven that radioactive tracer technique can be used to determine seepage losses from distributaries to biggest canal either unlined or lined in running condition without its closure or disturbing flow. Cost per test based on few tests is about Rs. 100,000/-which could be reduced to Rs. 60,000/-per test for the large scale investigations by creating facilities for drilling and fabrication of filters. The seepage tests can be repeated at the same locations using the existing wells at a cost of Rs. 15000/-. Therefore, this technique is also useful to evaluate the effectiveness of the lining or any other remedial measure. Considering the accuracy of the radiotracer technique and availability of facilities at reasonable cost, this novel technique may be applied at national level. (author)

  13. Transparent tooth model: A study of root canal morphology using different reagents

    Directory of Open Access Journals (Sweden)

    Bhavana Gupta

    2014-01-01

    Full Text Available Background: The complexity of root canal morphology has fascinated the imaginations of many. Several techniques have been tried in the past to view the three-dimensional anatomy of the pulp canal system with varied success. It has been hypothesized in the present study that a combination of decalcifying agent and clearing agent can be used to prepare transparent tooth model. Aims: The aim of the present study was to access the efficacy of two decalcifying agent (formic acid and nitric acid and two clearing agents (methyl salicylate and eugenol to prepare transparent tooth model. Materials and Methods: The study material included 80 freshly extracted teeth both maxillary and mandibular. After decalcifying and clearing of the specimen, they were graded for transparency and haziness criteria. Results: The results of the present study indicated that methyl salicylate when used as a clearing agent showed better transparency, lower level of haziness and good root canal morphology. On the other hand samples cleared by eugenol showed good root canal morphology but lesser transparency and higher degree of haziness and yellowing of samples, more so when used in combination with nitric acid. Conclusion: It was concluded by the present study that combination of nitric acid when used with methyl salicylate proved to be the best combination for the preparation of the transparent tooth model.

  14. Diagnostic capabilities of ultrasound study in stenosis of the spinal canal lumbar portion

    International Nuclear Information System (INIS)

    The performed investigations showed that ultrasound study allows easy and accurate calculation of the area of the spinal canal at the level f the disk as well as takes into consideration the characteristics of the hernia localization and its influence on the size of stenosis

  15. Evaluation of mineral trioxide aggregate as root canal sealer: A clinical study

    Directory of Open Access Journals (Sweden)

    Sophia Thakur

    2013-01-01

    Full Text Available Aim: The aim of this study was to compare the clinical and radiological outcome of mineral trioxide aggregate (MTA or epoxy resin as a root canal sealer compared with zinc oxide eugenol sealer. Materials and Methods: 45 single rooted teeth with periapical index Score 2 or more were allotted to three groups with 15 teeth in each group. Root canal treatment was performed in two visits and obturated with Gutta-percha as obturating material and zinc oxide eugenol as sealer in Group 1, epoxy resin as sealer in Group 2 and MTA mixed with propylene glycol as sealer in Group 3. Visual analog scale, periapical index and VixWin digital Pro image analysis software were used for evaluation. The quantitative data was analyzed by t-test and analysis of variance. Ordinal data was analyzed by Wilcoxon′s signed rank test, Mann-Whitney and Kruskall-Wallis test. Results: Results suggested that there exists no statistically significant difference in clinical or radiological outcome of root canal therapy with three different types of sealers used in this study. Conclusions: MTA could be used as a root canal sealer with equal effectiveness compared with epoxy resin and zinc oxide eugenol sealers. Further long-term studies should be carried out to prove the effectiveness.

  16. Comparison of different retreatment techniques and root canal sealers: a scanning electron microscopic study

    Directory of Open Access Journals (Sweden)

    Neslihan Simsek

    2014-05-01

    Full Text Available The aim of this study was to evaluate the effectiveness of two retreatment techniques, in terms of the operating time and scanning electron microscopy (SEM results, in removing three different root canal sealers from root canals that were previously filled with gutta-percha. Sixty extracted single-rooted human premolars were divided into three groups and filled with iRoot SP, MM Seal, and AH Plus sealers, along with gutta-percha, through a lateral compaction technique. Root canal fillings of the samples were removed by ESI ultrasonic tips or R-Endo files. The time to reach the working length was recorded. Longitudinally sectioned samples were examined under SEM magnification. Each picture was evaluated in terms of the residual debris. Data were statistically analyzed with the Kruskall-Wallis test. No statistically significant differences were found in terms of operating time (p>0.05. Significant differences in the number of debris-free dentinal tubules were found among the root canal thirds, but this finding was not influenced by the experimental group (p < 0.05. Resin sealer tags were observed inside the dentinal tubules in the MM Seal group. Under the conditions of this study, it may be established that there was no difference among the sealers and retreatment techniques.

  17. CT study of the performance of reciprocating and oscillatory motions in flattened root canal areas

    Directory of Open Access Journals (Sweden)

    Cacio MOURA-NETTO

    2015-01-01

    Full Text Available Root canal preparation is an important step in endodontic treatment. The anatomical complexity of the middle third of the root compromises the effective cleaning of this area. Thus, advances have been made in instrumentation techniques and instruments for this purpose. The aim of this study was to evaluate the effects of three different instrumentation systems on the enlargement of the middle thirds of root canals in mandibular incisors. The preparation methods used were the reciprocating systems Reciproc (Group I and WaveOne (Group II and the oscillatory system Tilos (Group III. Comparisons were made by three-dimensional image reconstruction with cone-beam computed tomography before and after instrumentation. Changes in area, perimeter, centering ability, and pattern of preparation were analyzed. The results were subjected to ANOVA complemented by the Tukey’s test. Changes in area, perimeter, and tendency of transportation showed similar results among groups. The transportation index of the Tilos system was significantly lower than that of the other groups. Qualitative analysis of the preparation pattern showed that the Tilos system had a more uniform preparation, although Reciproc and WaveOne preparations appeared more rounded, incompatible with the original canal anatomy. There was similarity in the systems’ performance on flattened areas, although the Tilos system presented a better pattern of root canal preparation and a lower index of transportation.

  18. CT study of the performance of reciprocating and oscillatory motions in flattened root canal areas

    Energy Technology Data Exchange (ETDEWEB)

    Moura-Netto, Cacio, E-mail: caciomn@usp.br [Universidade Cruzeiro do Sul (UNICSUL), Sao Paulo, SP (Brazil). Fac. de Odontologia; Palo, Renato Miotto [Universidade Estadual Paulista Julio de Mesquita Filho (ICT/UNESP), Sao Jose dos Campos, SP (Brazil). Instituto de Ciencia e Tecnologia; Pinto, Larissa Fernanda; Daltoe, Gisele; Mello-Moura, Anna Carolina Volpi [Universidade Ibirapuera (UNIB), Sao Paulo, SP (Brazil). Fac. de Odontologia

    2015-03-01

    Abstract: Root canal preparation is an important step in endodontic treatment. The anatomical complexity of the middle third of the root compromises the effective cleaning of this area. Thus, advances have been made in instrumentation techniques and instruments for this purpose. The aim of this study was to evaluate the effects of three different instrumentation systems on the enlargement of the middle thirds of root canals in mandibular incisors. The preparation methods used were the reciprocating systems Reciproc (Group I) and WaveOne (Group II) and the oscillatory system Tilos (Group III). Comparisons were made by three-dimensional image reconstruction with cone-beam computed tomography before and after instrumentation. Changes in area, perimeter, centering ability, and pattern of preparation were analyzed. The results were subjected to ANOVA complemented by the Tukey’s test. Changes in area, perimeter, and tendency of transportation showed similar results among groups. The transportation index of the Tilos system was significantly lower than that of the other groups. Qualitative analysis of the preparation pattern showed that the Tilos system had a more uniform preparation, although Reciproc and WaveOne preparations appeared more rounded, incompatible with the original canal anatomy. There was similarity in the systems’ performance on flattened areas, although the Tilos system presented a better pattern of root canal preparation and a lower index of transportation. (author)

  19. CT study of the performance of reciprocating and oscillatory motions in flattened root canal areas

    International Nuclear Information System (INIS)

    Abstract: Root canal preparation is an important step in endodontic treatment. The anatomical complexity of the middle third of the root compromises the effective cleaning of this area. Thus, advances have been made in instrumentation techniques and instruments for this purpose. The aim of this study was to evaluate the effects of three different instrumentation systems on the enlargement of the middle thirds of root canals in mandibular incisors. The preparation methods used were the reciprocating systems Reciproc (Group I) and WaveOne (Group II) and the oscillatory system Tilos (Group III). Comparisons were made by three-dimensional image reconstruction with cone-beam computed tomography before and after instrumentation. Changes in area, perimeter, centering ability, and pattern of preparation were analyzed. The results were subjected to ANOVA complemented by the Tukey’s test. Changes in area, perimeter, and tendency of transportation showed similar results among groups. The transportation index of the Tilos system was significantly lower than that of the other groups. Qualitative analysis of the preparation pattern showed that the Tilos system had a more uniform preparation, although Reciproc and WaveOne preparations appeared more rounded, incompatible with the original canal anatomy. There was similarity in the systems’ performance on flattened areas, although the Tilos system presented a better pattern of root canal preparation and a lower index of transportation. (author)

  20. Photoactivated disinfection (PAD) of dental root canal system – An ex-vivo study

    Science.gov (United States)

    Mohan, Dennis; Maruthingal, Sunith; Indira, Rajamani; Divakar, Darshan Devang; Al Kheraif, Abdulaziz Abdullah; Ramakrishnaiah, Ravikumar; Durgesh, B.H.; Basavarajappa, Santhosh; John, Jacob

    2015-01-01

    Aim To investigate the efficacy of photo activated disinfection (PAD) in reducing colony-forming unit (CFU) counts of Enterococcus faecalis (E. faecalis) in infected dental root canals. The study compared the efficacy of PAD with conventional endodontic treatment (CET) and also a combination of CET along with PAD. Material and Methods 53 maxillary incisors were taken for the study. Teeth were divided into 3 groups, CET (Group I) (n = 11), PAD (Group II) (n = 21), and a combination of CET and PAD (Group III) which consisted of (n = 21) samples, Group II and Group III were further divided into 2 subgroups, Group IIa, IIb and Group IIIa, IIIb. Strains of E. faecalis were inoculated in all the root canals. CET group samples were treated by chemo-mechanical preparation (CMP) alone, PAD samples were treated with laser alone at 2 different exposure time (4 min and 2 min). In the combination treatment, samples were treated initially by CET and then by PAD for a time period of 4 min and 2 min. Contents of the root canal were aspirated, diluted and plated in Tryptone Soya Broth (TSB) and plates were incubated for 24 h to observe the bacterial regrowth. Results Showed PAD used along with CMP reduced the bacterial load of E. faecalis by 99.5% at 4 min and 98.89% at 2 min. Conclusion PAD may be an adjunctive procedure to kill residual bacteria in the dental root canal systems after standard endodontic root canal preparation. PMID:26858548

  1. Efficacy of various root canal irrigants on removal of smear layer in the primary root canals after hand instrumentation: A scanning electron microscopy study

    OpenAIRE

    Hariharan V; Nandlal B; Srilatha K

    2010-01-01

    Aim: The purpose of this in-vitro study is to determine the efficacy of various irrigants in removing the smear layer in primary teeth root canals after hand instrumentation. Materials and Methods: The present study consisted of 30 human primary incisors which were sectioned at the cementoenamel junction horizontally. The specimens were divided randomly into four experimental and one control group having six teeth each and each group was treated with the specific irrigant. 5.25% NaOCl,...

  2. Clinical Treatment and Anatomy Study of Maxillary First Molars with Five Root Canals

    Institute of Scientific and Technical Information of China (English)

    Kuo Wan; Shun-yun Luo; Ji-zhi Zhao; Hai-yun Wang; Lin Ma; Wen-dong Yang

    2011-01-01

    @@ THE purpose of root canal treatment is to thoroughly clean the root canal system and fill it in all its dimensions.1 To achieve this goal, the entire root canal system must be adequately debrided and completely filled.In clinical practice, variations in the canal morphology pose a constant challenge to Received for publication April 26, 2011.

  3. Estudo experimental do sequenciamento das manobras da ligamentotaxia na descompressão do canal vertebral Experimental study of ligamentotaxis maneuvers sequencing in vertebral canal decompression

    Directory of Open Access Journals (Sweden)

    Ilton José Carrilho de Castro

    2008-01-01

    Full Text Available A descompressão do canal vertebral, para aliviar as estruturas nervosas, pode ser realizada por meio da ligamentotaxia. O objetivo foi analisar a influência da seqüência de realização da ligamentotaxia sobre a descompressão do canal vertebral. Foram utilizados segmentos de vértebras de suínos (Landrace. Um equipamento especialmente desenvolvido foi utilizado para produção de fratura do tipo explosão. Após a tomografia computadorizada, 10 espécimes que melhores apresentavam fraturas do tipo explosão foram fixados com fixador interno (Synthes. Foram formados dois grupos. No primeiro (n=5 foi realizada a lordose e depois a distração. Posteriormente, foram submetidos à nova compressão por meio de morsa até o retorno da fratura à posição inicial, a seguir foram novamente submetidos à distração e lordose. No segundo grupo (n=5 foi realizada a distração e depois a lordose. Após cada manobra era realizado o exame tomográfico para medir o diâmetro do canal vertebral. Os deslocamentos dos fragmentos dos corpos vertebrais fraturados foram mensurados e comparados utilizando t de Student (pVertebral canal decompression, intended to provide relief to nervous structures, may be performed by means of legamentotaxis. The objective of this study was to assess the influence of the ligamentotaxis sequence on vertebral canal decompression. Vertebral segments of Landrace swine specimens were used. A device especially developed for producing a burst-type fracture was employed. Subsequently to the computerized tomography scan, 10 specimens that best showed a burst-type fracture were fixated with internal fixator (Synthes. Two groups were formed. On the first group (n=5, lordosis followed by distraction were performed. Then, they were submitted to distraction and lordosis. On the second group (n=5, distraction was provided first, and then lordosis was performed. After each maneuver, vertebral canal was measured by tomography scan

  4. Working length changes in curved canals after coronal flaring by using rotary files and hand file: An in vitro study

    OpenAIRE

    Rahul Kumar; Neha Khambete; Suvarna Patil; Upendra Hoshing; Ashish Medha; Roshan Shetty

    2013-01-01

    Aim: This in vitro investigation examined the effect of early coronal flaring (CF) and late CF on the working length (WL) in curved root canals. Background: The objective of this study was to determine if canal length is altered as a result of CF in curved canals of molar roots. Study Design: The conditions compared were combinations of (a) stainless steel hand files using Gates Glidden (G. G.) drills (SS) versus nickel-titanium rotary files (Ni-Ti); and (b) early CF (flaring complete...

  5. COMPARATIVE STUDY OF CHELATION VALUE OF SEVENTEEN PERCENT SELF DEVELOPED AND COMMERCIALLY AVAILABLE ROOT CANAL LUBRICANTS

    OpenAIRE

    Ingale Satish Dinkarrao; Kankariya Rajendra

    2013-01-01

    The main objective of this study is to compare chelation values of 17% self developed & commercially available root canal Lubricants or dental chelating gels as well as to see whether their performance depends on the chelation value or not. The Chelating agent bounds Ca2+ ions of the smear layer & the extent of chelate formation between chelating agent and metal ion is nothing but Chelation Value. Sodium carbonate indicator method is used for determinations of chelation value. Commercially av...

  6. Study of water flow velocities in irrigation canals in Iraq and their mathematical analysis

    Science.gov (United States)

    de Araoz, Joaquin

    1962-01-01

    Water velocity is an important physical factor in the conditioning of streams and canals as habitats for the intermediate snail host of bilharziasis. Ecologists in most of the bilharziasis endemic areas have studied the resistance of these molluscs to the disturbing action of water motion. However, the complex nature of water flow through natural and man-made courses makes it very difficult to determine accurately the limiting range of water velocity that allows the settlement and development of snail colonies in a watercourse, and results are therefore still inconclusive. This paper describes the procedure employed in and the results obtained from a study designed to elucidate the water flow phenomenon through analysis of the relative variations of water velocity at any point of the cross-section of the canal. From this study it was possible to derive a simplified method for measuring the rate of water flow in earth canals that may be of wide application in snail control by the use of molluscicides. PMID:13884110

  7. STUDY OF VARIATION OF THE DIAMETER OF THE SPINAL CANAL AND THE FORAMINA IN SPONDYLOLISTHESIS

    Directory of Open Access Journals (Sweden)

    Enguer Beraldo Garcia

    2016-03-01

    Full Text Available ABSTRACT Objective: To define and quantify the degree of change of the spinal canal diameter in patients with degenerative and spondylolytic spondylolisthesis. Methods: We studied CT scans of 54 patients. Of this total, 37 (29 women and 8 men had degenerative type and 17 (7 women and 10 men had spondylolytic type. Results: In the degenerative spondylolisthesis group, the average diameter of the spinal canal at the injured vertebra level was 17.35 mm and 17.64 mm for the upper vertebra level. The average diameter of the foramen at the level of the affected vertebra was 14.61 mm to left side and 15.00 mm to the right side. The average diameter of the foramen at the upper vertebra level was 16.82 mm to the left side and 16.51 mm to the right side. In the spondylolytic group, the average diameter of the spinal canal at the level of the affected vertebra was 23.25 mm and at the upper vertebra level was 18.66 mm. The average diameter of the foramen at the level of the affected vertebra was 11.98 mm to the left side and 12.34 mm to the right side. The average diameter of the foramen at the level of the upper vertebra was 16.97 mm to the left side and 15.58 mm to the right side. Conclusion: The diameter of the spinal canal in the sagittal plane showed no statistically significant increase in the spondylolytic spondylolisthesis group, in contrast to what is found in the degenerative spondylolisthesis group. It was also observed a reduction in vertebral foramina of the injured level in both groups.

  8. Dispositivo de posicionamiento de muestras biológicas para su irradiación en un canal radial de un reactor nuclear

    OpenAIRE

    Maritza Rodríguez - Gual; Felix Mas – Milián; Airton Deppman; Paulo Rogerio Pinto - Coelho

    2011-01-01

    Por la demanda de un dispositivo experimental para el posicionamiento de las muestras biológicas para su irradiación en un canal radial de un reactor nuclear de investigaciones en funcionamiento, se construyó y se puso en marcha un dispositivo para la colocación y retirada de las muestras en la posición de irradiación de dicho canal. Se efectuaron las valoraciones económicas comparando con otro tipo de dispositivo con las mismas funciones. Este trabajo formó parte de un proyecto internacional...

  9. Environmental studies on water quality of the Ismailia Canal/Egypt

    Energy Technology Data Exchange (ETDEWEB)

    Stahl, Ralph [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany). Inst. fuer Technische Chemie; Ramadan, Abou Bakr [Atomic Energy Authority (AEA), National Centre for Nuclear Safety and Radiation Control, Cairo (Egypt)

    2008-08-15

    The inorganic chemical water quality of the Ismailia Canal / Egypt was studies in 2003 and 2004 at seventeen different sites from the main canal between Cairo and Ismailia. Additional samples were taken from selected discharges and groundwater sources. As the Ismailia Canal is fed by water from the Nile some samples were taken from the Nile near Aswan for comparative reasons too. Water samples were analysed for sum parameters, salts, heavy metals and natural radioactivity. Especially in the Greater Cairo Area due to different uncontrolled discharges pH and conductivity changed significantly when proceeding from up to downstream sites. The water temperature increased significantly during the first 20 km. The main reason was the discharge of warm water used to cool machinery in the industrial suburb of Cairo. Iron, Zinc and Manganese were found in low concentrations. Because of dilution effects the amounts of dissolved salts were still below the German ''Trinkwasserverordnung''. A higher total organic carbon level indicated the presence of organic contaminants however. The natural radioactivity level was in the normal range. (orig.)

  10. Studies on the pathogenesis of degenerative lumbar canal stenosis by computed tomography, 2. Investigation about measurements of the lumbar canal

    Energy Technology Data Exchange (ETDEWEB)

    Kido, Kenji

    1987-07-01

    To evaluate the significance of measurement parameters for the lumbar canal (LC), a retrospective analysis was made of computed tomography (CT) scans in a total of 129 patients, including 20 with degenerative lumbar canal stenosis (DLCS), 65 with degenerative spondylosis, 21 with disc hernia, and 23 with lumbar pain. The shape of the transverse LC was not reflected by the anteroposterior and transverse diameters of LC, but was somewhat reflected by the transverse area of LC. The transverse area of dural sac (DS) was considered important in determining the degree of stenosis. Regarding the transverse area, the DS correlated more strongly with the LC with soft-tissue windows than that with bone windows. The angle of intervertebral joint was likely to be related to the pathophysiology of the LC. In particular, sagittal tendency was seen at the levels of L3-4 and L4-5 in the DLCS group. There was correlation between the angle of intervertebral joint and the transverse areas of both soft-tissue LC and DS at the levels of L4-5. A multivariate analysis suggested the possibility that the significance of measurement parameters might vary depending on the vertebral level for the lower lumbar spine. The following criteria for indicating DLCS were obtained: 1) a transverse area of less than or equal to 100 mm/sup 2/ for DS or less than or equal to 118 mm/sup 2/ for soft-tissue LC at the levels of L3-4; 2) a transverse area of less than or equal to 90 mm/sup 2/ for DS and an angle of less than or equal to 90 deg for the intervertebral joint at the levels of L4-5; and 3) lateral recess of less than or equal to 3 mm in anteroposterior diameter at the levels of L5-S1. (Namekawa, K.).

  11. Minimal Apical Enlargement for Penetration of Irrigants to the Apical Third of Root Canal System: A Scanning Electron Microscope Study

    OpenAIRE

    P. Srikanth; Krishna, Amaravadi Gopi; Srinivas, Siva; Reddy, E Sujayeendranatha; Battu, Someshwar; Aravelli, Swathi

    2015-01-01

    Background: The aim of this study was to determine minimal apical enlargement for irrigant penetration into apical third of root canal system using scanning electron microscope (SEM). Materials and Methods: Distobuccal canals of 40 freshly extracted human maxillary first molar teeth were instrumented using crown-down technique. The teeth were divided into four test groups according to size of their master apical file (MAF) (#20, #25, #30, #35 0.06% taper), and two control groups. After final ...

  12. In vitro study of the apical microleakage with resilon root canal filling using different final endodontic irrigants

    OpenAIRE

    Lahor Soler, Eduard; Miranda Rius, Jaume; Brunet Llobet, Lluis; Farré Albaladejo, Magí; Pumarola Suñé, José

    2015-01-01

    Background Endodontic microleakage or microfiltration refers to the percolation of fluids and micro-organisms at the interface of the obturation material and the walls of the root canal system. The aim of this in vitro study was to compare apical microfiltration of Resilon root canal filling by employing three different final irrigant solutions. Material and Methods 128 single-rooted teeth were employed. The crowns were sectioned horizontally at the cemento-enamel junction and instrumented wi...

  13. Comparison of Antimicrobial Efficacy of IKI and NaOCl Irrigants in Infected Root Canals: An In Vivo Study

    OpenAIRE

    Abbaszadegan, Abbas; Khayat, Akbar; Motamedifar, Mohammad

    2010-01-01

    INTRODUCTION Effective debridement of the root canal system with chemical irrigants prior to obturation is the key to long-term success of endodontic therapy. The purpose of this study is to compare the antibacterial activity of 2.5% sodium hypochlorite (NaOCl) and 2% iodine potassium iodide (IKI) solutions as intracanal disinfectant in infected root canals during one-visit endodontic treatment procedure. MATERIALS AND METHODS Thirty single-rooted teeth with necrotic pulps in 27 patients were...

  14. Effect of 95% Ethanol as a Final Irrigant before Root Canal Obturation in Primary Teeth: An in vitro Study

    Science.gov (United States)

    Thiruvenkadam, G; John, Baby; Priya, PR Geetha

    2016-01-01

    ABSTRACT Background: Successful obturation in the primary teeth demands complete dryness of the root canal system. Aim: The purpose of this study was to determine the effect of 95% ethanol as the final irrigant before root canal obturation in primary teeth. Materials and methods: A total of 20 extracted primary mandibular canines were biomechanically prepared and pre-obturated volume of each tooth was assessed using spiral computed tomography (CT). The specimens were divided into two groups (n = 10): group 1, Metapex group; group 2, zinc oxide eugenol group. Each group was further divided randomly into two subgroups (n = 5): subgroup 1, canals were dried with 95% ethanol; subgroup 2, canals were blot dried with paper points with the last one appearing dry. All canals were obturated and the postobturated volume of each tooth was measured. The percentage of obturated volume (POV) was calculated using the formula: (postobturated volume/preobturated volume) × 100. The POV between the groups was statistically analyzed using Mann-Whitney test and Wilcoxon Signed rank test appropriately. Results: Root canals that were dried with ethanol showed better obturation than using paper points alone and the difference was statistically significant in both group 1 (p < 0.001) and group 2 (p < 0.002). Conclusion: Drying of the root canal system with 95% ethanol can result in better obturation in the primary teeth. How to cite this article: Thiruvenkadam G, Asokan S, John B, Geetha Priya PR. Effect of 95% Ethanol as a Final Irrigant before Root Canal Obturation in Primary Teeth: An in vitro Study. Int J Clin Pediatr Dent 2016;9(1):21-24. PMID:27274150

  15. Efficacy of various root canal irrigants on removal of smear layer in the primary root canals after hand instrumentation: A scanning electron microscopy study

    Directory of Open Access Journals (Sweden)

    Hariharan V

    2010-01-01

    Full Text Available Aim: The purpose of this in-vitro study is to determine the efficacy of various irrigants in removing the smear layer in primary teeth root canals after hand instrumentation. Materials and Methods: The present study consisted of 30 human primary incisors which were sectioned at the cementoenamel junction horizontally. The specimens were divided randomly into four experimental and one control group having six teeth each and each group was treated with the specific irrigant. 5.25% NaOCl, 5.25% NaOCl + 10% EDTA, 6% citric acid, 2% chlorhexidine, saline (control were the irrigants evaluated for efficacy in removal of smear layer. The specimens were split along the longitudinal axis using a chisel after placing superficial grooves in cementum not extending to the root canal. The exposed surface was subjected to scanning electron microscopic analysis to reveal the efficacy of irrigants in removal of smear layer. The representative areas were evaluated twice at 15 days interval by a single evaluator. The scale for the smear layer removal by Rome et al was modified and used in the present study. Results: The pictures from the scanning electron microscopy showed that among the tested irrigants, citric acid has the best efficacy to remove the smear layer without altering the normal dentinal structures, which was supported by the lowest mean smear scores. The pictures from the 10%EDTA + 5.25% sodium hypochlorite group showed that even though it removed the smear layer, it adversely affected the dentine structure. SEM pictures of the other groups like sodium hypochlorite, chlorhexidine revealed that these irrigants does not have the capacity to remove the smear layer in primary teeth. Conclusions: The results of the present study clearly indicate the superior efficacy of 6% citric acid than the other tested irrigants on removing the smear layer in primary teeth root canals.

  16. Scanning electron microscopy study of the adhesion of Prevotella nigrescens to the dentin of prepared root canals.

    Science.gov (United States)

    Yang, Sung-Eun; Bae, Kwang-Shik

    2002-06-01

    The purpose of this study was to evaluate the effect of the presence or absence of amorphous, irregular smear layers on the adhesion of Prevotella nigrescens, to the dentin of the root canal by using scanning electron microscopy (SEM). Human incisors extracted within 7 days, with no cavities, no fractures, and no evidence of calcification of the canal, were selected. After cutting the crown portion at the CEJ, root canal preparation was undertaken by using a modified crown-down technique with Profile and Gates Glidden drills. Ten milliliters of physiologic saline solution (groups 1 and 4), 10 ml of 3.5% NaOCl (groups 2 and 5), or 10 ml of NaOCl and 10 ml of 0.5 M EDTA (groups 3 and 6) were used as irrigation solution while preparing the canal. After vertical sectioning and ethylene oxide gas sterilization, samples (groups 1, 2, and 3) were immersed in brain-heart infusion broth with yeast extract, hemin, and menadione, inoculated with P. nigrescens (ATCC 33563), and incubated for 3 h at 37 degrees C. All samples were prepared for and observed with SEM. The data were analyzed by using t test and one-way ANOVA. Smear layer was observed to cover the entire root canal surface after root canal preparation. Smear layer was removed and the entrances of dentinal tubules opened widely after applying 3.5% NaOCl and 0.5 M EDTA. A significantly greater number of bacteria were found to adhere to those teeth in which a smear layer was present (p root canal preparation promoted adhesion and colonization of P. nigrescens to the dentin matrix, it might also increase the likelihood of canal reinfection. PMID:12067123

  17. Diagnostic imaging study of the relationship between the mandibular third molar and mandibular canal. Use of helical computed tomography for multiplanar reconstruction

    International Nuclear Information System (INIS)

    We aimed to evaluate the ability of panoramic radiography to reflect the information provided by three-dimensional CT scans of the mandibular third molar and mandibular canal by comparing panoramic radiographs with CT scans. Panoramic radiography was used to evaluate the superimposition of the third molar root apex with the mandibular canal and deflection of the mandibular canal at the third molar root apex. Deflection and compression of the mandibular canal was detected by cine display of cross-sectional images. For each case, panoramic radiographs and Tooth-Pix images of the CT scans were compared. Results showed a higher incidence of mandibular canal deflection with an increase in overlap between the mandibular canal and third molar root apex. In the present study, a bone wall was absent more often in cases in which the mandibular canal traveled on the lingual side than in cases in which it traveled on the buccal side and above the tooth axis. Therefore, it may be necessary to carefully examine morphology as well as anatomic position when analyzing the mandibular canal image. It may be necessary to pay closer attention during tooth extraction when the root apex is below the lower mandibular canal wall, or when widening of the mandibular canal by a considerable portion of the third molar is observed on panoramic radiograph. Therefore, pre-surgical CT may be needed to determine the positional relationship when mandibular canal deflection at the root apex is detected by panoramic radiography. (author)

  18. Relationship of central incisor implant placement to the ridge configuration anterior to the nasopalatine canal in dentate and partially edentulous individuals: a comparative study

    OpenAIRE

    Jia, Xueting; Hu, WenJie; Meng, Huanxin

    2015-01-01

    Background. The aims of this study were to investigate the ridge contour anterior to the nasopalatine canal, and the difference between the incidences of the nasopalatine canal perforation in dentate and partially edentulous patients by cone-beam computed tomography. Methods. Cone-beam computed tomography scan images from 72 patients were selected from database and divided into dentate and partially edentulous groups. The configuration of the ridge anterior to the canal including palatal conc...

  19. Evaluation of the sealing ability of resin cement used as a root canal sealer: An in vitro study

    Directory of Open Access Journals (Sweden)

    R Vinod Kumar

    2012-01-01

    Full Text Available Aim: This study was designed to evaluate the apical seal of root canals obturated with resin cement as a root canal sealer and compare with that of the glass ionomer and zinc oxide eugenol sealers using a cold lateral condensation gutta-percha technique. Background: Successful root canal treatment requires three-dimensional obturation of the root canal system with nonirritating biomaterials. None of the available materials are capable of providing a fluid tight seal. Materials and Methods: The prepared teeth were randomly divided into three groups of 15 each to be obturated using three different sealers. Group I: zinc oxide eugenol (Tubliseal, Group II: Glass ionomer (Ketac Endo, and Group III: resin cement (C & B Superbond. All the specimens were stored in 100% relative humidity at 37° for 24 h. The specimens were placed in 2% methylene blue dye for 48 h and sectioned. The dye penetration was evaluated under a stereomicroscope. Results: The "Kruskal-Wallis" test was carried out to test the equality of mean. All the specimens showed dye leakage, and there was a statistically significant difference (P < 0.0001 among the groups. The specimens in Group III showed a minimal leakage and the specimens in Group I showed a maximum leakage. Conclusion: Resin cement sealed the root canals significantly better when compared with zinc oxide eugenol and glass ionomer sealers.

  20. Clinical and radiographic evaluation of pulpectomies using three root canal filling materials: An in-vivo study

    Directory of Open Access Journals (Sweden)

    Ramar K

    2010-03-01

    Full Text Available Various root canal filling materials are used to preserve a pulpally involved carious primary tooth. But there is no single material so far available to fulfill all the requirements of an ideal root canal filling material for a primary tooth. Hence this study was undertaken to evaluate clinically and radiographically the efficacy of three obturating materials - Calcium hydroxide with Iodoform (METAPEX, Zinc Oxide Eugenol with Iodoform (RC FILL and Zinc Oxide Eugenol and Calcium hydroxide with Iodoform (ENDOFLAS for a period of 9 months. Results show ENDOFLAS gave an overall success rate of 95.1%, METAPEX - 90.5% and RC FILL - 84.7%. In our study, we conclude that ENDOFLAS, a mixture of Zinc Oxide Eugenol and Calcium hydroxide with Iodoform fulfills most of the required properties of an ideal root canal filling for primary teeth.

  1. canal24

    Data.gov (United States)

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

  2. An In Vitro Comparative Study of the Adaptation and Sealing Ability of Two Carrier-Based Root Canal Obturators

    OpenAIRE

    Ahmed Alkahtani; Sara Al-Subait; Sukumaran Anil

    2013-01-01

    The study was done to assess the sealing ability and adaptation of RealSeal 1, and to compare it with Thermafil. 65 single-rooted extracted teeth were selected and root canal treatment was performed. Root canals were obturated with RealSeal 1 or Thermafil. A double chamber bacterial leakage model using E. faecalis was developed to assess the sealing ability. Samples were monitored daily for 60 days. After the bacterial leakage test, samples were embedded in resin and sectioned horizontally at...

  3. Smear layer removal capacity of disinfectant solutions used with and without EDTA for the irrigation of canals: a SEM study

    Directory of Open Access Journals (Sweden)

    Menezes Ana Carolina Silveira Cardoso de

    2003-01-01

    Full Text Available The purpose of this study was to carry out a scanning electron microscopic (SEM analysis of the cleaning qualities and smear layer removal from root canal walls, instrumented and irrigated with 2.5% NaOCl, 2.0% chlorhexidine and saline solutions. Fifty extracted teeth were used in this study. All teeth were radiographed to determine the existence of a single canal. The crowns were cut at the cervical limit and the root canals were instrumented with K-type files up to size 45. During root canal preparation, irrigations were made with the different solutions being evaluated: Group 1: 2.5% NaOCl (10 roots; Group 2: 2.5% NaOCl and 17% EDTA for 2 minute (10 roots; Group 3: 2.0% chlorhexidine (10 roots; Group 4: 2.0% chlorhexidine and 17% EDTA for 2 minutes (10 roots; Group 5: saline solution (5 roots; Group 6: saline solution and 17% EDTA for 2 minutes (5 roots. After instrumentation, the canals were irrigated with each one of the solutions and the roots were cut in the buccolingual direction for SEM analysis, at the cervical, middle and apical thirds, to ascertain the presence or absence of smear layer and debris. SEM analysis was performed by three calibrated examiners and scores were submitted to Kruskal-Wallis test at the significance level of p = 5%. Results showed that the use of 17% EDTA decreased the smear layer significantly (p < 0.05 for all evaluated solutions in all thirds. When EDTA was not used, a significantly higher quantity of smear layer on the apical third was observed only in the NaOCl groups. The use of 17% EDTA was significant for debris removal except for the chlorhexidine groups. The following conclusion could be drawn: the use of 17% EDTA was necessary to enhance cleanness of the root canals.

  4. Sealing ability of hydroxyapatite as a root canal sealer: in vitro study

    Directory of Open Access Journals (Sweden)

    Widowati Witjaksono

    2007-09-01

    Full Text Available Hydroxyapatite (HA is the most thermodynamically synthetic calcium phosphate cement, and has indicated useful as a sealer because can seal a furcation perforation, is shown to be biocompatible and also has potential to promote the healing of bone in endodontic therapy. The objective of this study is to determine the sealing ability of HA produced by School of Engineering, Universiti Sains Malaysia (USM when used as a sealer in root canal obturation, compare with Tubli-seal (Zinc-Oxide base and Sealapax (Calcium Hydroxyde base sealers. Forty five single rooted human anterior teeth were instrumented and randomly divided into three experimental groups of 15 teeth each. All teeth in the experimental groups were obturated with laterally condensed gutta percha technique. Teeth in the first group were sealed using Zinc-Oxide (ZnO based sealer and those of second group using Calcium Hydroxide (CaOH based root canal sealer. Third experimental group was sealed using HA from School of Engineering USM. Teeth were then suspended in 2% methylene blue. After this, teeth were demineralized dehydrated and cleared. Linear dye penetration was determined under magnifying lense with calibrated eye piece. Statistical analyses of the linear dye penetration were performed with Kruskal Wallis test. The intergroup comparison between HA and ZnO groups and CaOH groups were analyzed by Mann-Whitney test. The dye penetration for group which were sealed with HA exhibited the lowest penetration and it showed that there was a statistically significant difference both between HA and ZnO groups and also between HA and CaOH groups (p < 0.001.In conclusion, it was found that value added HA based endodontic material which were produced by USM can be used as a root canal sealing materials when it used in combination with epoxy resin since it leaked comparatively less as compared to ZnO and CaOH sealers. Before reaching a definitive conclusion, this material requires further extensive

  5. Qualitative study of root canal shaping during ultrasonic instrumentation with different files

    Directory of Open Access Journals (Sweden)

    Cleber Keiti NABESHIMA

    2009-12-01

    Full Text Available Introduction and objective: The proposal of this study was to verifythe quality of ultrasonic instrumentation shaping influenced by different types of files – K, K-flex and nickel-titanium – and different trademarks. Material and methods: 30 blocks with simulated canals were divided randomly in three groups in agreement with type of file and trademark. They were prepared by crown-down technique, with apical third prepared in agreement with the division. Results: Through statistical analysis it was possible to notice that the group of K-flex files FKG® obtained statistically significant difference when compared to groups K FKG®, K Dentsply-Maillefer® and K-flex Dentsply-Maillefer®. The group of K-flex files Dentsply-Maillefer® has also showed difference when compared to group of nickel-titanium files FKG®. Conclusion:The ultrasonic system can cause apical alteration with lacerated foramen, and the trademark can influence the final result.

  6. Tsetsaut History: The Forgotten Tribe of Southern Southeast Alaska. Portland Canal Early History (Misty Fiord National Monument). Alaska Historical Commission Studies in History #147.

    Science.gov (United States)

    Dangeli, Reginald H.

    Written by one of the tribe's few remaining members and based on oral history and legend, this study traces the history of the Tsetsaut tribe, ancient original inhabitants of the Portland Canal area of southeastern Alaska. Chapters recount the quest for the coast, legends of Portland Canal, exploration of the area, material culture, establishment…

  7. A preliminary study of the percentage of gutta-percha-filled area in the apical canal filled with vertically compacted warm gutta-percha

    NARCIS (Netherlands)

    Wu, MK; van der Sluis, LWM; Wesselink, PR

    2002-01-01

    Aim The aim of this study was to determine the influence of the width of apical root canals and the depth of heat application during warm vertical compaction on the percentage of gutta-percha-filled area (PGFA) in the apical root canal. Methodology Two groups of extracted human canines (total 60) we

  8. The Sealing Ability of Resilon and Gutta-Percha in Severely Curved Root Canals: An In Vitro Study

    Directory of Open Access Journals (Sweden)

    Armita Rouhani

    2013-01-01

    Full Text Available Objective: The aim of this study was to compare the apical seal of curved canals obturated with Resilon/Epiphany with gutta-percha/AH Plus.Materials and Methods: Thirty-four extracted human mandibular molars with 25-40 degree canal curvature of the mesial root were selected for this study. After preparation, the mesiobuccal canals were obturated with gutta-percha and AH- Plus sealer (group G or Resilon and Epiphany sealer (group R. Four specimens served as control. Microleakage was evaluated after passing 3 and 30 days using the fluid filtration technique. The data were analyzed statistically using parametric tests.Results: In the 3-day evaluation, the mean microleakage in group R was significantly less than in group G (P 0.05. In group G, the leakage values at the end of 30 days were significantly less than values at the end of 3 days. Although in group R the mean leakage decreased after 30 days, this reduction was not statistically significant.Conclusion: Resilon/Epiphany provided a better seal than gutta-percha/AH-Plus in severely curved root canals immediately after obturation, although with the passage of time, Resilon/Epiphany was equivalent to gutta-percha/AH Plus in sealing properties.

  9. Studies of nuclear processes

    International Nuclear Information System (INIS)

    Results for the period 1 Sep 92 through 31 Aug 93 are presented in nearly a hundred brief papers, some of which present new but preliminary data. Activities reported may be grouped as follows: Fundamental symmetries in the nucleus (parity-mixing measurements, time reversal invariance measurements, signatures of quantum chaos in nuclei), Internucleon reactions (neutron -- proton interactions, the neutron -- neutron scattering length, reactions between deuterons and very light nuclei), Dynamics of very light nuclei (measurements of D states of very light nuclei by transfer reactions, nuclear reactions between very light nuclei, radiative capture reactions with polarized sources), The many-nucleon problem (nuclear astrophysics, high-spin spectroscopy and superdeformation, the nuclear mean field: Dispersive relations and nucleon scattering, configuration mixing in 56Co and 46Sc using (d,α) reactions, radiative capture studies, high energy resolution resonance studies at 100--400 keV, nuclear data evaluation for A=3--20), Nuclear instruments and methods (FN tandem accelerator operation, KN accelerator operation and maintenance, atomic beam polarized ion source, development of techniques for determining the concentration of SF6 in the accelerator insulating gas mixture, production of beams and targets, detector systems, updating of TeX, Psprint, and associated programs on the VAX cluster), and Educational Activities

  10. Cone-beam computed tomography study of the root and canal morphology of mandibular permanent anterior teeth in a Chongqing population

    Science.gov (United States)

    Zhengyan, Yang; Keke, Lu; Fei, Wang; Yueheng, Li; Zhi, Zhou

    2016-01-01

    Objective To investigate the root and canal morphology of permanent mandibular anterior teeth in a Chongqing population using cone-beam computed tomography (CBCT). Methods CBCT images of 1,725 patients in a Chongqing population were selected, and a total of 9,646 mandibular anterior teeth were analyzed. The number of root canals and the canal configurations were investigated. Results In total, 0.3% (11/3,257) of lateral incisors and 0.8% (26/3,014) of canines had double roots, and 3.8% (127/3,375) of central incisors, 10.6% (345/3,257) of lateral incisors, and 4.2% (127/3,014) of canines had multi-root canals. The difference in the incidence of multi-canals in lateral incisors between female and male was statistically significant. The frequency of multi-canals in the different age groups was 5.0% for central incisors for ages 21–30 years, 14.7% for lateral incisors for ages 41–50 years, and 8.1% for canines for ages 41–50 years. Conclusion With the limitations of the current study, we found that a high percentage of mandibular anterior teeth had multiple canals in the studied Chinese Chongqing population. The current data may provide clinicians practicing in Chongqing with a more thorough understanding of root canal morphology. PMID:26730198

  11. Nontumorous enlargement of the internal auditory canal. A risk factor for sensorineural hearing loss? A high resolution CT-study

    Energy Technology Data Exchange (ETDEWEB)

    Stimmer, H.; Rummeny, E.J. [Technical University Munich, Klinikum rechts der Isar (Germany). Dept. of Radiology; Niedermeyer, H.P. [Technical University Munich, Klinikum rechts der Isar (Germany). ENT-Clinic; Kehl, V. [Technical University Munich, Klinikum rechts der Isar (Germany). Inst. for Medical Statistics and Epidemiology

    2015-06-15

    First aim of the study was to define normal shape and diameter of the internal auditory canal (IAC). In the second part the clinical relevance of IAC-enlargement was analyzed, considering also lesions of the subtle structures at the fundus of the internal auditory canal. 440 high resolution CT-scans of the temporal bone were used for retrospective analysis of the internal auditory canal and its fundus region. The mean value of the IAC diameter in axial and coronal plane was determined. In 20 of 440 patients IAC enlargement was found. In the group with pronounced enlargement (3fold SD) nearly all patients suffered from hearing impairment. In some of them we found structural abnormalities near the IAC fundus in the CSF/perilymph border zone. A new CT-based definition of normal shape and diameter of the internal auditory canal is presented. There is some evidence that a pathologic transmission of CSF-pressure in case of IAC-enlargement and/or abnormal fistulous communications could play an important role in the pathophysiology of hearing loss.

  12. Nontumorous enlargement of the internal auditory canal. A risk factor for sensorineural hearing loss? A high resolution CT-study

    International Nuclear Information System (INIS)

    First aim of the study was to define normal shape and diameter of the internal auditory canal (IAC). In the second part the clinical relevance of IAC-enlargement was analyzed, considering also lesions of the subtle structures at the fundus of the internal auditory canal. 440 high resolution CT-scans of the temporal bone were used for retrospective analysis of the internal auditory canal and its fundus region. The mean value of the IAC diameter in axial and coronal plane was determined. In 20 of 440 patients IAC enlargement was found. In the group with pronounced enlargement (3fold SD) nearly all patients suffered from hearing impairment. In some of them we found structural abnormalities near the IAC fundus in the CSF/perilymph border zone. A new CT-based definition of normal shape and diameter of the internal auditory canal is presented. There is some evidence that a pathologic transmission of CSF-pressure in case of IAC-enlargement and/or abnormal fistulous communications could play an important role in the pathophysiology of hearing loss.

  13. Analysis of sedimentation of canals

    Directory of Open Access Journals (Sweden)

    Agunwamba, J.C.,

    2013-03-01

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

  14. Nuclear spectroscopic studies

    International Nuclear Information System (INIS)

    The Nuclear Physics group at UTK is involved in heavy-ion physics including both nuclear structure and reaction mechanisms. During the last year experimental work has been in 3 broad areas: structure of nuclei at high angular momentum, structure of nuclei far from stability, and ultra-relativistic heavy-ion physics. Results in these areas are described in this document under: properties of high-spin states, study of low-energy levels of nuclei far from stability, and high-energy heavy-ion physics (PHENIX, etc.). Another important component of the work is theoretical interpretation of experimental results (Joint Institute for Heavy Ion Research)

  15. K-file vs ProFiles in cleaning capacity and instrumentation time in primary molar root canals: An in vitro study

    Directory of Open Access Journals (Sweden)

    N Madan

    2011-01-01

    Full Text Available Objectives: This study compares the efficiency of manual K-files and rotary ProFiles in cleaning capacity and instrumentation time in primary molar root canals. Materials and Methods: Seventy-five maxillary and mandibular primary molar root canals were instrumented with ProFiles and K-files in the step-back manner from size #10 to #40. The teeth were decalcified, dehydrated and cleared, and analyzed for the presence of dye remaining on the root canal walls, which served as an evidence of cleaning capacity of both the techniques. Results: The results showed a significant difference in the cleaning capacity of the root canals with ProFiles and K-files, in apical and coronal thirds of the root canal. ProFiles have been found to be more efficient in cleaning the coronal thirds and K-files in cleaning apical thirds of the root canals. Both the techniques were almost equally effective in cleaning the middle thirds of the canals. The time taken during the cleaning of the root canals appeared to be statistically shorter with K-files than profiles.

  16. Study on Character of Micro-Canal Deposit and Its Significance in Petroleum Geology --Case study of Tuo-147-well in north zone of Dongying depression

    Institute of Scientific and Technical Information of China (English)

    吴李泉; 曹代勇; 刘里勤; 刘艳华

    2003-01-01

    Exploration on reservoir of glutenite segment in steep slope zone of half graben-like basin is one of the hot spot targets at present and in the future for new reservoirs; And the study of sediment character of sandy-conglomerate bodies is the keystone and also the difficult problem. Taking Tuo-147-well area in north zone of Dongying depression as an example, the micro-canal sedimentation was researched. The result shows that many micro-canals exist at the end of slope grain-flow in steep slope zone of half graben-like basin; The micro-canals grow at the end of subaqueous grain-flow deposited bodies of 3rd member of the Shahejie formation. The main condition of micro-canal formation is the slope angle less than 18° and a long suitable sedimentary slope. These micro-canals may communicate the reservoir of glutenite segment in steep slope zone and the hydrocarbon stratum as a bridge role. Therefore, it is significant in theory and practice for discovering a series of micro-canals at the end of slope grain-flow in steep slope zone of half graben-like basin.

  17. Retrospective study of root canal configurations of maxillary third molars in Central India population using cone beam computed tomography Part- I

    Science.gov (United States)

    Rawtiya, Manjusha; Somasundaram, Pavithra; Wadhwani, Shefali; Munuga, Swapna; Agarwal, Manish; Sethi, Priyank

    2016-01-01

    Objective: The aim of this study was to investigate the root and canal morphology of maxillary third molars in Central India population using cone-beam computed tomography (CBCT) analysis. Materials and Methods: CBCT images of 116 maxillary third molars were observed, and data regarding the number of roots, the number of canals, and Vertucci's Classification in each root was statistically evaluated. Results: Majority of Maxillary third molars had three roots (55.2%) and three canals (37.9%). Most MB root (43.8%), DB root (87.5%), and palatal root (100%) of maxillary third molars had Vertucci Type I. Mesiobuccal root of three-rooted maxillary third molars had Vertucci Type I (43.8%) and Type IV (40.6%) configuration. Overall prevalence of C-shaped canals in maxillary third molars was 3.4%. Conclusion: There was a high prevalence of three-rooted maxillary molars with three canals. PMID:27011747

  18. A comparative study between the efficacy of tramadol, celecoxib and ibuprofen in pain control after root canal therapy of tooth

    OpenAIRE

    Eshagh A Saberi; S. Mohsen Hosseini-Goosheh; Roohollah Mirkahnooj; Hossein Ansari

    2011-01-01

    Background: Root canal therapy of teeth can relief the endodontic pain, but post-endodontic pain and discomfort are its undesirable effects. There are many studies on various drugs for alleviation of post-endodontic pain. The aim of this study was to compare the analgesic effect of tramadol, celecoxib and ibuprofen in vital teeth.Materials & Method: In this double blind randomized clinical trial study, 104 patients with vital first mandibular molar tooth were selected. The patients were divid...

  19. Anal Canal Cancer: Management of Inguinal Nodes and Benefit of Prophylactic Inguinal Irradiation (CORS-03 Study)

    International Nuclear Information System (INIS)

    Purpose: To evaluate the benefit of prophylactic inguinal irradiation (PII) in anal canal squamous cell carcinoma (ASCC). Methods and Materials: This retrospective study analyzed the outcome of 208 patients presenting with ASCC treated between 2000 and 2004 in four cancer centers of the south of France. Results: The population study included 35 T1, 86 T2, 59 T3, 20 T4, and 8 T stage unknown patients. Twenty-seven patients presented with macroscopic inguinal node involvement. Of the 181 patients with uninvolved nodes at presentation, 75 received a PII to a total dose of 45–50 Gy (PII group) and 106 did not receive PII (no PII group). Compared with the no PII group, patients in the PII group were younger (60% vs. 41% of patients age 2 toxicity of the lower extremity was observed. Conclusion: PII with a dose of 45 Gy is safe and highly efficient to prevent inguinal recurrence and should be recommended for all T3-4 tumors. For early-stage tumors, PII should also be discussed, because the 5-year inguinal recurrence risk remains substantial when omitting PII (about 10%).

  20. Nuclear site selection studies

    International Nuclear Information System (INIS)

    It is of special importance, especially from the nuclear safety viewpoint, to select suitable sites for different nuclear structures with the considered future activities. Site selection sometimes involves high costs not necessarily for merely selecting of site but for some preliminary measures to be taken so as the site may have the necessary characteristics. The more suitable the natural characteristics of the site for the considered project, the more successful and efficient the project, the lower the project costs and the longer the project operation period. If so, the project will cause the growth of public culture and sustainable socioeconomic development. This paper is the result of the conclusion of numerous massive reports of this activity in the preliminary phase based on theories, practices and the related safety principles on this ground as well as the application of data and information of the past and a glance to the future. The conception of need for a site for medium structures and nuclear research projects and how to perform this process are presented step by step here with a scientific approach to its selection during the investigations. In this study, it is practically described how the site is selected, by determining and defining the characteristics of research and nuclear projects with medium structures and also its fitting to the optimum site. The discovered sites typically involve the best advantages in technical and economic aspects and no particular contrast with the concerned structures

  1. In vitro study of apical leakage of root canals after different root apex resection techniques

    Directory of Open Access Journals (Sweden)

    André Augusto Franco MARQUES

    2008-12-01

    Full Text Available Objective:The aim of the present study was to evaluate in vitro apicalmarginal leakage of root canals after three root apex resectiontechniques.Material and methods: Thirty maxillary canines wereprepared chemo-mechanically to a size 40 master apical file, andenlarged by using Gates Glidden burs 2, 3 and 4. Teeth were obturatedby Tagger thermomechanical compaction technique and then dividedinto three groups (n = 10. The first group (GI was 3 mm apicalresected with Endo Z in high speed handpiece. The specimens of secondgroup (GII were 3 mm apical weared with Endo Z, and the third group(GIII had 3 mm apical resected with Er:YAG laser (500 impulse, 12pps and 300 mJ energy. After the apical sections, IRM cement wasplaced into the root-end cavity and teeth of each group were immersedin India ink for 5 days and submitted to decalcification and clarifying for marginal apical microleakage visualization with microscope.Results: The results showed statistically difference (p < 0.01 between GI and the other groups.Conclusion: The root apex cut using Endo Z promotes the lowest values of microleakage when used in apicoectomy.

  2. CANAL code

    International Nuclear Information System (INIS)

    The CANAL code presented here optimizes a realistic iron free extraction channel which has to provide a given transversal magnetic field law in the median plane: the current bars may be curved, have finite lengths and cooling ducts and move in a restricted transversal area; terminal connectors may be added, images of the bars in pole pieces may be included. A special option optimizes a real set of circular coils

  3. Nuclear standardization development study

    International Nuclear Information System (INIS)

    Nuclear industry is the important part of national security and national economic development is key area of national new energy supported by government. nuclear standardization is the important force for nuclear industry development, is the fundamental guarantee of nuclear safe production, is the valuable means of China's nuclear industry technology to the world market. Now nuclear standardization faces to the new development opportunity, nuclear standardization should implement strategy in standard system building, foreign standard research, company standard building, and talented people building to meet the requirement of nuclear industry development. (author)

  4. Multistate nested canalizing functions

    CERN Document Server

    Adeyeye, J O; Laubenbacher, R; Li, Y

    2013-01-01

    The concept of a nested canalizing Boolean function has been studied over the course of the last decade in the context of understanding the regulatory logic of molecular interaction networks, such as gene regulatory networks. Such functions appear preferentially in published models of such networks. Recently, this concept has been generalized to include multi-state functions, and a recursive formula has been derived for their number, as a function of the number of variables. This paper carries out a detailed analysis of the class of nested canalizing functions over an arbitrary finite field. Furthermore, the paper generalizes the concept further, and derives a closed formula for the number of such generalized functions. The paper also derives a closed formula for the number of equivalence classes under permutation of variables. This is motivated by the fact that two nested canalizing functions that differ by a permutation of the variables share many important properties with each other. The paper contributes ...

  5. Root canal treatment of pulpless immature teeth using calcium hydroxide paste. Roentgenographic study

    International Nuclear Information System (INIS)

    Calcium hydroxide paste was used as a temporary dressing and the renewal was done each three months in the root treatment of immature teeth with open apex and necrotic pulps. Clinical and radiographic controls were made to observe foraminal closure. After that, the root canals were filled, employing the conventional technique with gutta-percha cones and zinc oxide eugenol cements. The calcium hydroxide paste was applied in the apical region before the root canal filling. The follow-up was done periodically and the cases have more than two years of control. (author)

  6. Comparative evaluation of antimicrobial effect of herbal root canal irrigants (Morinda citrifolia, Azadirachta indica, Aloe vera) with sodium hypochlorite: An in vitro study

    Science.gov (United States)

    Babaji, Prashant; Jagtap, Kiran; Lau, Himani; Bansal, Nandita; Thajuraj, S.; Sondhi, Priti

    2016-01-01

    Aim and Objectives: Successful root canal treatment involves the complete elimination of microorganism from the root canal and the three-dimensional obturation of the canal space. Enterococcus faecalis is the most commonly found bacteria in failed root canal. Chemical irrigation of canals along with biomechanical preparation helps in the elimination of microorganisms. The present study was aimed to evaluate the antimicrobial effect of herbal root canal irrigants (Morinda citrifolia, Azadirachta indica extract, Aloe vera) with sodium hypochlorite (NaOCl). Materials and Methods: The bacterial E. faecalis (ATCC) culture was grown overnight in brain heart infusion (BHI) broth and inoculated in Mueller–Hinton agar plates. Antibacterial inhibition was assessed using agar well diffusion method. All five study irrigants were added to respective wells in agar plates and incubated at 37°C for 24 h. Bacterial inhibition zone around each well was recorded. Results were tabulated and statistically analyzed using Statistical Package for the Social Sciences software for Windows, version 19.0. (IBM Corp., Armonk, NY. Results: Highest inhibitory zone against E. faecalis was seen in NaOCl fallowed by M. citrifolia and A. indica extract, and the least by A. vera extract. Conclusion: Tested herbal medicine (A. indica extract, M. citrifolia, A. vera) showed inhibitory zone against E. faecalis. Hence, these irrigants can be used as root canal irrigating solutions. PMID:27382533

  7. CBVT analysis of canal configuration of the mesio-buccal root of maxillary first permanent molar teeth: An in vitro study

    Directory of Open Access Journals (Sweden)

    R Pratima Shenoi

    2012-01-01

    , 29.16% in middle 3 rd and 16.66% were in apical 3 rd . Conclusion: Within the limitations of this study, it can be concluded that- (1 more than half of maxillary first molars have four canals and (2 most of the additional canals were located in the MBR and CBVT is a good diagnostic tool to help diagnose these additional canals. Further investigations using larger sample sizes would be helpful.

  8. Nuclear spectroscopic studies

    International Nuclear Information System (INIS)

    The Nuclear Physics group at the University of Tennessee, Knoxville is involved in several aspects of heavy-ion physics including both nuclear structure and reaction mechanisms. While our main emphasis is on experimental problems involving heavy-ion accelerators, we have maintained a strong collaboration with several theorists in order to best pursue the physics of our measurements. During the last year we have led several experiments at the Holifield Heavy Ion Research Facility and participated in others at Argonne National Laboratory. Also, we continue to be very active in the collaboration to study ultra-relativistic heavy ion physics utilizing the SPS accelerator at CERN in Geneva, Switzerland and in a RHIC detector R ampersand D project. Our experimental work is in four broad areas: (1) the structure of nuclei at high angular momentum, (2) heavy-ion induced transfer reactions, (3) the structure of nuclei far from stability, and (4) ultra-relativistic heavy-ion physics. The results of studies in these particular areas will be described in this document in sections IIA, IIB, IIC, and IID, respectively. Areas (1), (3), and (4) concentrate on the structure of nuclear matter in extreme conditions of rotational motion, imbalance of neutrons and protons, or very high temperature and density. Area (2) pursues the transfer of nucleons to states with high angular momentum, both to learn about their structure and to understand the transfer of particles, energy, and angular momentum in collisions between heavy ions. An important component of our program is the strong emphasis on the theoretical aspects of nuclear structure and reactions

  9. Nuclear spectroscopic studies

    Energy Technology Data Exchange (ETDEWEB)

    Bingham, C.R.; Guidry, M.W.; Riedinger, L.L.; Sorensen, S.P.

    1993-02-08

    The Nuclear Physics group at the University of Tennessee, Knoxville is involved in several aspects of heavy-ion physics including both nuclear structure and reaction mechanisms. While our main emphasis is on experimental problems involving heavy-ion accelerators, we have maintained a strong collaboration with several theorists in order to best pursue the physics of our measurements. During the last year we have led several experiments at the Holifield Heavy Ion Research Facility and participated in others at Argonne National Laboratory. Also, we continue to be very active in the collaboration to study ultra-relativistic heavy ion physics utilizing the SPS accelerator at CERN in Geneva, Switzerland and in a RHIC detector R D project. Our experimental work is in four broad areas: (1) the structure of nuclei at high angular momentum, (2) heavy-ion induced transfer reactions, (3) the structure of nuclei far from stability, and (4) ultra-relativistic heavy-ion physics. The results of studies in these particular areas will be described in this document in sections IIA, IIB, IIC, and IID, respectively. Areas (1), (3), and (4) concentrate on the structure of nuclear matter in extreme conditions of rotational motion, imbalance of neutrons and protons, or very high temperature and density. Area (2) pursues the transfer of nucleons to states with high angular momentum, both to learn about their structure and to understand the transfer of particles, energy, and angular momentum in collisions between heavy ions. An important component of our program is the strong emphasis on the theoretical aspects of nuclear structure and reactions.

  10. Evaluation of resistance of teeth subjected to fracture after endodontic treatment using different root canal sealers: An in vitro study

    Directory of Open Access Journals (Sweden)

    S S Bhat

    2012-01-01

    Full Text Available Aims: The aim of this study was to compare the ex-vivo effects of different root canal sealers on the fracture resistance of endodontically treated teeth. Materials and Methods: Seventy-five freshly extracted human mandibular premolars were used for the study. The length was standardized to 14 mm and all the teeth were biomechanically prepared and divided into five different groups based on the type of root canal sealers used. Group I:- Roeko seal + gutta percha, Group II: AH plus ® root canal sealer + gutta percha, Group III: PULPDENT root canal sealer + gutta percha, Group IV: Zinc oxide-eugenol sealer + gutta percha, Group V: Control (unobturated teeth. The teeth were embedded in acrylic resin blocks and compressive strengths were measured using universal testing machine (Instron. Statistical Analysis Used: One-way ANOVA, unpaired t- test Results: Data obtained were statistically evaluated using one-way ANOVA and unpaired t-test. All groups showed a statistically significant result (P < 0.05. Teeth obturated with Group I and Group II showed higher resistance to fracture than teeth obturated with other three Groups. It was seen that the teeth obturated with group III showed a better fracture resistance than Group IV and there was no statistical significance found between Group and Group V. Conclusions: From this study, it has been concluded that both the resin based sealers that were used in this study were equally effective compared to that of the zinc oxide-based sealers and the control group. However, no significant results were obtained when the comparison was made between zinc oxide-eugenol and gutta-percha and the control group.

  11. Comparative Evaluation of Sealing Ability of Three Newer Root Canal Obturating Materials Guttaflow, Resilon and Thermafil: An In Vitro Study

    OpenAIRE

    H Bhandi, Shilpa; T.S., Subhash

    2013-01-01

    Introduction: Microleakage continues to be a main reason for failure of root canal treatment where the challenge has been to achieve an adequate seal between the internal structure and the main obturating material. The objective of this study is to compare the sealing ability of 3 newer obturating materials GuttaFlow, Resilon/Epiphany system (RES) and Thermafil, using silver nitrate dye and observing under stereomicroscope.

  12. A STUDY OF MORPHOLOGY, MORPHOMETRY, SYMMETRY AND DEVELOPMENT OF EXTERNAL OPENING OF CAROTID CANAL WITH COMPARISON IN MALE, FEMALE AND FOETUS

    Directory of Open Access Journals (Sweden)

    Vaseemraja G. Shaikh

    2014-12-01

    Full Text Available Introduction: The Carotid Canal is an important structure at the base of skull as it conveys the internal carotid artery, along with a sympathetic nerve plexus and a venous plexus. Previous researches done on carotid canal suggest that abnormalities to this canal, such as fractures of carotid canal and carotid sympathetic plexus schwannoma have their effect on the internal carotid artery and the structures passing through it. Cases of absence of carotid canal have also been reported, which causes variations of the internal carotid artery. Attempt has been made in this study to give a detailed view of the ‘external opening of carotid canal’ (EOCC which is the gateway of the carotid canal at the skull base. This study shall be useful for Surgeons, Radiologists, Anatomists, Forensic Experts, Anthropologists, etc. Aim: This study aims at measuring the various dimensions of the external openings of the carotid canal pair present at the base of skull, and to observe the age changes, sexual dimorphism, and symmetry of the external opening of the carotid canal from the analysis of these measurements. Materials and methods: Total 235 dry skulls that included 181 adolescent to adult skulls of known age and sex (age ranging from 13 years up to old age skulls of 60 years or above and 54 foetal skulls were studied for this purpose. The longest & shortest diameter of each carotid canal, was measured using a screw adjusted compass and a Vernier Calliper. Their distance from pharyngeal tubercle and from the X axis and Y axis was measured. Observations and Results: In the present study, it was observed that external opening of each carotid canal was unique in its morphology and morphometry. The dimensions of external opening of carotid canal progressively increased from foetal age to 25 years of age, however after 25 years of age, it did not show any age change within same sex, but it showed age changes when adolescent female skulls of age less than 25 years

  13. Pico Hydropower Application on Tidal Irrigation CanalSupporting The Indonesian Agricultural Activities Case Study: Telang II – Banyuasin

    Directory of Open Access Journals (Sweden)

    Darmawi Darmawi

    2013-01-01

    Full Text Available A review of waterwheel history has conducted to evaluate the possibility and thetechnology development in its relation to harvest the energy from the flowing water inand out of irrigation canal regarding the tidal movement. The study has conducted atthe east shore of South Sumatra. Hydro energy became a promising renewable energyin order to achieve at least 5% of total Indonesian national energy mix consumption in 2025. Tidal turbine energy is technologically potential for Indonesian futureregarding the beach of 81,000 kilometers long and 20 millions hectares of tidalswamp area out of 33 millions hectares available. Mechanical torque of 30 Nm isproduced by a waterwheel of 0.38 meter radius. An estimation of 60 watt at the peakof rain season could harvested from each tidal irrigation canal in Telang II. Thismechanical energy is applicable to generate small quantity water pump, water aerationinjector and small electric energy energy appliances.

  14. Nuclear spectroscopic studies

    International Nuclear Information System (INIS)

    The Nuclear Physics group at the University of Tennessee, Knoxville is involved in several aspects of heavy-ion physics including both nuclear structure and reaction mechanisms. While our main emphasis is on experimental problems involving heavy-ion accelerators, we have maintained a strong collaboration with several theorists in order to best pursue the physics of our measurements. During the last year we have led experiments at the Holifield Heavy Ion Research Facility, the SuperHILAC at Berkeley, and Chalk River Tandem Accelerator. Also, we have joined a collaboration to study ultra-relativistic heavy ion physics and one of our group has spent all of 1987 at CERN to work on the WA80 experiment. Our experimental work is in four broad areas: (1) the structure of nuclei at high angular momentum, (2) heavy-ion induced transfer reactions, (3) the structure of nuclei far from stability, and (4) ultra-relativistic heavy-ion physics. These results will be described in this document in sections 2A, 2B, 2C, and 2D, respectively. Areas (1), (3), and (4) concentrate on the structure of nuclear matter in extreme conditions of rotational motion, imbalance of neutrons and protons or very high temperature and density. Area (2) pursues the transfer of nucleons to states with high angular momentum, both to learn about their structure and to understand the transfer of particles, energy and angular momentum in collisions between heavy ions. An important component of our program is the strong emphasis on the theoretical aspects of nuclear structure and reactions

  15. Nuclear spectroscopic studies

    International Nuclear Information System (INIS)

    The Nuclear Physics group at the University of Tennessee, Knoxville is involved in several aspects of heavy-ion physics including both nuclear structure and reaction mechanisms. While our main emphasis is on experimental problems involving heavy-ion accelerators, we have maintained a strong collaboration with several theorists in order to best pursue the physics of our measurements. During the last year we have led experiments at the Holifield Heavy Ion Research Facility, the SuperHILAC at Berkeley, and Chalk River Tandem Accelerator. Also, we have joined a collaboration to study ultra-relativistic heavy ion physics and one of our group has spent all of 1987 at CERN to work on the WA80 experiment. Our experimental work is in four broad areas: (1) the structure of nuclei at high angular momentum, (2) heavy-ion induced transfer reactions, (3) the structure of nuclei far from stability, and (4) ultra-relativistic heavy-ion physics. These results will be described in this document in sections IIA, IIB, and IID, respectively. Areas (1), (3), and (4) concentrate on the structure of nuclear matter in extreme conditions of rotational motion, imbalance of neutrons and protons, or very high temperature and density. Area (2) pursues the transfer of nucleons to states with high angular momentum, both to learn about their structure and to understand the transfer of particles, energy and angular momentum in collisions between heavy ions. An important component of our program is the strong emphasis on the theoretical aspects of nuclear structure and reactions

  16. A clinical and radiographic study of four different root canal fillings in primary molars

    Directory of Open Access Journals (Sweden)

    Alaa O Al-Ostwani

    2016-01-01

    Full Text Available Background: Successful treatment of infected primary teeth aims to preserve the child′s health. However, the complex morphology of primary root canals and the desire for shorter therapy sessions put the necessity to search for the ideal root canal paste. Aims: To evaluate pulpectomy of nonvital primary molars using four different root canal filling pastes zinc oxide and propolis (ZOP as a new paste, endoflas-chlorophenol-free as a new paste free of chlorophenol, metapex paste, and zinc oxide and eugenol (ZOE paste as a control paste. Materials and Methods: Pulpectomy of 64 nonvital primary molars were accomplished in 39 children aged 3-9 years. Teeth were randomly divided into four equal groups of 16 molars according to the type of root canal filling. Pulpectomy was performed in one stage using 5.25% sodium hypochlorite irrigation and stainless-steel crown for final restoration. Clinical and radiographic results were evaluated double-blindly for two periods of 6, 12 months. Data were analyzed using Chi-square/Fisher′s exact test, and P-value was set as 0.05. Results: The four pastes achieved convergent clinical and radiographic success within the two observation periods (P > 0.05. ZOE paste was the slowest in its resorption. Conclusions: ZOP is a promising paste with its natural antibacterial component (propolis. ZOE paste had convergent efficacy to the other pastes.

  17. Root Canal Therapy Reduces Multiple Dimensions of Pain: A National Dental PBRN Study

    Science.gov (United States)

    Law, Alan S.; Nixdorf, Donald R.; Rabinowitz, Ira; Reams, Gregory J.; Smith, James A.; Torres, Anibal V.; Harris, D. Robert

    2014-01-01

    Background Initial orthograde root canal therapy (RCT) is used to treat dentoalveolar pathosis. The affect RCT has on pain intensity has been frequently reported, but the affect on other dimensions of pain has not. Also, the lack of large prospective studies involving diverse groups of patients and practitioners that are not involved in data collection suggest that there are multiple opportunities for bias to be introduced when this data is systematically aggregated. Method This prospective observational study assessed pain intensity, duration, and its interference with daily activities among RCT patients. Sixty-two practitioners (46 general dentists, 16 endodontists) in the National Dental Practice-Based Research Network enrolled patients requiring RCT. Patient reported data were collected before, immediately following, and one week after treatment using the Graded Chronic Pain Scale. Results Enrollment of 708 patients was completed over 6 months with 655 patients (93%) providing one-week follow-up data. Prior to treatment, patients reported a mean (±standard deviation) worst pain intensity of 5.3±3.8 (0-10 scale), 50% had “severe” pain (≥7), and mean days in pain and days pain interfered with activities were 3.6±2.7 and 0.5±1.2, respectively. Following treatment, patients reported a mean worst pain intensity of 3.0±3.2, 19% had “severe” pain, and mean days in pain and days with pain interference were 2.1±2.4 and 0.4±1.1, respectively. All changes were statistically significant (p<0.0001). Conclusions RCT is an effective treatment for patients experiencing pain, significantly reducing pain intensity, duration, and related interference. Further research is needed to reduce the proportion of patients reporting “severe” post-operative pain. PMID:25190605

  18. An In Vitro Comparative Study of the Adaptation and Sealing Ability of Two Carrier-Based Root Canal Obturators

    Directory of Open Access Journals (Sweden)

    Ahmed Alkahtani

    2013-01-01

    Full Text Available The study was done to assess the sealing ability and adaptation of RealSeal 1, and to compare it with Thermafil. 65 single-rooted extracted teeth were selected and root canal treatment was performed. Root canals were obturated with RealSeal 1 or Thermafil. A double chamber bacterial leakage model using E. faecalis was developed to assess the sealing ability. Samples were monitored daily for 60 days. After the bacterial leakage test, samples were embedded in resin and sectioned horizontally at 2 and 4 mm from the apical foramen. Specimens were examined under scanning electron microscope and digitally photographed. AutoCAD software was used to measure the gap between the canal surface and obturation material. Results were statistically analyzed using nonparametric Kaplan-Meier survival analysis for the bacterial leakage and t-test to compare the means of gap in RealSeal 1 and Thermafil at 2 and 4 mm. There was no significant difference between the RealSeal 1 and Thermafil with respect to leakage over time. At 2 mm and 4 mm, RealSeal 1 had significantly more gaps than Thermafil. From the observations it can be concluded that RealSeal 1 and Thermafil have comparable performance in terms of adaptation and sealing ability.

  19. An in vitro comparative study of the adaptation and sealing ability of two carrier-based root canal obturators.

    Science.gov (United States)

    Alkahtani, Ahmed; Al-Subait, Sara; Anil, Sukumaran

    2013-01-01

    The study was done to assess the sealing ability and adaptation of RealSeal 1, and to compare it with Thermafil. 65 single-rooted extracted teeth were selected and root canal treatment was performed. Root canals were obturated with RealSeal 1 or Thermafil. A double chamber bacterial leakage model using E. faecalis was developed to assess the sealing ability. Samples were monitored daily for 60 days. After the bacterial leakage test, samples were embedded in resin and sectioned horizontally at 2 and 4 mm from the apical foramen. Specimens were examined under scanning electron microscope and digitally photographed. AutoCAD software was used to measure the gap between the canal surface and obturation material. Results were statistically analyzed using nonparametric Kaplan-Meier survival analysis for the bacterial leakage and t-test to compare the means of gap in RealSeal 1 and Thermafil at 2 and 4 mm. There was no significant difference between the RealSeal 1 and Thermafil with respect to leakage over time. At 2 mm and 4 mm, RealSeal 1 had significantly more gaps than Thermafil. From the observations it can be concluded that RealSeal 1 and Thermafil have comparable performance in terms of adaptation and sealing ability. PMID:23710141

  20. Frequency, impact, and predictors of persistent pain after root canal treatment: a national dental PBRN study.

    Science.gov (United States)

    Nixdorf, Donald R; Law, Alan S; Lindquist, Kimberly; Reams, Gregory J; Cole, Emery; Kanter, Keith; Nguyen, Ruby H N; Harris, D Robert

    2016-01-01

    Root canal treatment (RCT) is commonly performed surgery and persistent pain is known to occur, but little is known about how these patients are affected by this pain. Although biopsychosocial mechanisms are thought to be associated with the development of such pain, similar to persistent pain after surgery in other body sites, little is known about the baseline predictors for persistent pain. We assessed the frequency of persistent pain 6 months after RCT, measured the impact this pain had on patients, and determined predictive factors for persistent tooth pain in a multicenter prospective cohort study conducted within the National Dental Practice-Based Research Network. Of 708 patients enrolled, 651 (91.9%) provided follow-up data, with 65 (10.0%) meeting criteria for pain 6 months after RCT. On average, these patients reported their pain as mild to moderate in intensity, present for approximately 10 days in the preceding month, and minimally interfered with daily activities. After adjusting for the type of dental practitioner and patient age, gender, and household income, pain duration over the week before RCT significantly increased the risk of developing persistent pain (odds ratio = 1.19 per 1 day increase in pain duration, 95% confidence interval: 1.07-1.33), whereas optimism about the procedure reduced the risk (odds ratio = 0.39, 95% confidence interval: 0.22-0.67). Our data suggest that persistent pain 6 months after RCT is fairly common, but generally does not have a large impact on those experiencing it. Furthermore, patient age and gender did not predict persistent pain, whereas preoperative pain duration and the patient's expectation did. PMID:26335907

  1. Computed tomography of the thoracic canal

    International Nuclear Information System (INIS)

    Under the adequate CT condition, thoracic canal was studied in twelve normal cases, nine cases of cervical myelopathy with developmental cervical canal stenosis and four cases of thoracic myelopathy with ossification of thoracic yellow ligament. The results were as follows. 1) The adequate condition for delineation of thoracic canal seemed to be nearly 400 EMI units in window width and 150 in level. Scanning angle was permitted within about 100. Bony thoracic canal was well scanned at the center of vertebral body. 2) The configulation of the normal thoracic canal was oval at Th1, Th2 levels and round at Th3-Th10 and large oval at Th11, Th12. The sagittal diameter was almost fixed at each level and the transverse diameter was large at upper and lower levels and small at middle levels. 3) Thoracic canal was narrowed in the cases of cervical myelopathy with developmental cervical canal stenosis especially in sagittal diameter, but not narrowed in transverse diameter. Three of four cases who had myelopathy with ossification of thoracic yellow ligament had narrow canals. 4) There was a good relation between sagittal diameter of cervical canal and thoracic canal. 5) There was a good relation between sagittal diameter of thoracic canal measured by conventional radiographs (Hattori's method) and CT scans. The author thinks that Hattori's method is useful to diagnose the thoracic canal stenosis. (author)

  2. Application of CT image measurement of human nasal sinuses in anatomical study of optic canal location

    International Nuclear Information System (INIS)

    Objective: To locate the optic canal precisely by measuring related distances and angles between optic canal and certain landmarks. Methods: 120 CT images from clinical database were chosen for measurement. The line (L1) of the nasal bone tip (P1) and the point of tuberculum sellae (P2) in centre sagittal plane were set as a baseline. The plane went through L1 and perpendicular to centre sagittal plane (L2) was set as measurement plane. The parameters were the medial canal wall length (D1), the distance between nasal bone tip (P1) and orbit end of optic canal (P3) (D2), the distance between P1 and cranium end of optic canal (P4) (D3), the distance between P3 and L2 (D4), the distance between P4 and L2 (D5), the angle between P1P3 and L2 (A1), and the angle between P1P4 and L2 (A2). Results: D1 was (10.51±1.07) mm on the left, (10.64±1.10) mm on the right, statistical difference was found between the two sides (P<0.05). D2 was (66.68±5.99) mm on the left, (66.81±5.97) mm on the right, there was no statistical difference between the two sides (P>0.05), D3 was (72.82±6.33) mm on the left, (73.04±6.33) mm on the right, statistical difference was found between the two sides (P<0.05). D4 was (13.96±1.43)mm on the left, (14.16±1.53) mm on the right, there was no statistical difference between the two sides (P>0.05). D5 was (6.65±1.25) mm on the left, (6.58±1.41) mm on the right, there was no statistical difference between the two sides (P>0.05). A1 was (12.26±1.63)°, and A2 (5.28±1.13)°. Conclusion: The parameters above can help to locate the optic canal precisely in the measurement plane and provide reference for the decompression surgery. It also makes the surgery safer. (authors)

  3. The study of transit time measurement for flow through the central and southern canals of MADA using I-131 radioisotope technique

    International Nuclear Information System (INIS)

    The measurement of breakthrough and transit time through the central and southern canals of Lembaga Kemajuan Pertanian Muda (MADA) by using radiotracer technique is discussed An estimated of 1700 cusec water was released from Pelubang regulator through central canal. The water is then distributed through several regulators down stream and finally ended through the SCD1 and SCD1a secondary canals. Radiotracer 1-131 with the activity of 250 mCi and 500 mCi were injected at several identified injection points by using glass breaker technique. The measurement of breakthrough and transit time were observed respectively at several measurement station. Results of the study indicated that the time travel from Pelubang regulator to SCD1a secondary canal would take about 3 days during normal operation. Detail of breakthrough and transit time at every regulators and other measurement stations were also presented

  4. Evaluation of the Apical Sealability of Mineral Trioxide Aggregate and Portland Cement as Root Canal Filling Cements: An in Vitro Study

    Directory of Open Access Journals (Sweden)

    M.S. Rekab

    2010-12-01

    Full Text Available Objective: One of the principle purposes of root canal obturation is to obtain hermetic sealing of the root canal system. According to the development of technology, many materials are now used in root canal filling. An in vitro dye leakage study was performed toevaluate the apical sealability of White-colored Mineral Trioxide Aggregate (WMTA and Gray-colored Portland Cement (GPC when used alone or as a sealer with gutta-percha points in root canal filling.Materials and Methods: Seventy-five single-rooted extracted human teeth were used in this study. After cleaning and shaping, the teeth were randomly divided into five equal groups of 15 teeth each based on the root canal filling material used; Group 1, (WMTAalone; Group 2, (GPC alone; Group 3, (Gutta-percha points + WMTA; Group 4,(Guttapercha points + GPC; Group 5, (Gutta-percha points + AH26. Methylene blue was used to determine the apical leakage. After sectioning the teeth longitudinally, linear dye penetrationwas measured with a caliper under the stereomicroscope. Data were analyzed by Kruskal-Wallis and one-way ANOVA tests with (P 0.05 as the level of significance.Results: The results showed that there were no statistically significant differences among the materials of five groups.Conclusion: (WMTA alone, (Gutta-percha points + WMTA, (GPC alone and (Guttapercha points + GPC may be used in the root canal filling.

  5. Nuclear spectroscopic studies: Progress report

    International Nuclear Information System (INIS)

    Research efforts of the University of Tennessee Nuclear Physics Group can be divided into five broad categories; the structure of nuclei at high angular momentum, nuclear structure and reactions with heavy ions, studies of low-energy levels of nuclei far from stability, nuclear physics with ultrarelativistic particles, and nuclear structure and reaction theory. Within these five broad categories, forty separate research projects are summarized. In addition, development and organization projects are reviewed and a list of publications is provided

  6. Nuclear medicine technology study guide

    CERN Document Server

    Patel, Dee

    2011-01-01

    Nuclear Medicine Technology Study Guide presents a comprehensive review of nuclear medicine principles and concepts necessary for technologists to pass board examinations. The practice questions and content follow the guidelines of the Nuclear Medicine Technology Certification Board (NMTCB) and American Registry of Radiological Technologists (ARRT), allowing test takers to maximize their success in passing the examinations. The book is organized by sections of increasing difficulty, with over 600 multiple-choice questions covering all areas of nuclear medicine, including radiation safety; radi

  7. Root canal irrigants

    OpenAIRE

    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...

  8. A Comparison of Push-Out Bond Strength of Two Endodontic Sealers to Root Canal Dentin: An in Vitro Study

    Directory of Open Access Journals (Sweden)

    Adl A

    2016-03-01

    Full Text Available Statement of Problem: Adhesion to root canal dentin is one of the necessary characteristics of endodontic sealers. MTA Fillapex (Angelus, Londria, PR, Brazil is one of the recently introduced MTA-based sealer. Only a limited number of studies have evaluated the bonding of this sealer to the dentin, with conflicting results. Objectives: The purpose of this study was to evaluate the bond strength of MTA Fillapex sealer to root canal dentin compared to an epoxy resinbased sealer (AH26 sealer. Materials and Methods: Twenty root blocks (6mm length were acquired from the middle part of the extracted single-rooted central or lateral maxillary incisor roots and their lumens were enlarged to achieve a diameter of 1.3 mm. MTA Fillapex and AH26 were placed in the lumens of root blocks (n = 10. The specimens were kept in an incubator for 7 days, the roots were sectioned perpendicular to their long axis to achieve slices with thickness of 1 mm and the push-out test was carried out by a universal testing machine. Results: The mean value of bond strength was 1.84 ± 0.7 Mpa for AH26 and 0.19 ± 0.1 Mpa for MTA Fillapex. The difference between the two groups was statistically significant (p < 0.001. Conclusions: With in the limitation of this study, AH 26 showed significantly higher bond strength in comparison to MTA Fillapex.

  9. Studies on Trypanosoma rangeli Tejera, 1920: V - Developmental pattern in the alimentary canal of Rhodnius prolixus

    Directory of Open Access Journals (Sweden)

    N. Añez

    1983-06-01

    Full Text Available The morphological sequence of Trypanosoma rangeli development in the alimentary canal of Rhodnius prolixus, is described, with observation made in dissected guts from 6 hours to 45 days post-infection. No metacyclic-forms are produced in the digestive tract at any time, and transmission by the contaminative route must be considered atypical. Amastigotes appear to be an essential stage in the development of T. rangeli in the gut of R. prolixus. The epidemiological importance of the developmental pattern of T. rangeli in the vector´s gut is discussed, and its usefulness for aging infection is considered.A seqüência do desenvolvimento morfológico do Trypanosoma rangeli no canal alimentar do Rhodnius prolixus, é descrita, segundo observações, em intestinos dissecados desde 6 horas até 45 dias pós-infecção. Não se produzem formas metacíclicas no trato digestivo em tempo algum, e a transmissão por via contaminativa deve-se considerar atípica. Os amastigotos aparentam ser um estágio essencial no desenvolvimento do T. rangeli no intestino do R. prolixus. A importância epidemiológica do padrão de desenvolvimento do T. rangeli é discutida e a sua utilidade na determinação da idade na infecção é considerada.

  10. Evaluation of dentinal defect formation after root canal preparation with two reciprocating systems and hand instruments: an in vitro study

    Science.gov (United States)

    Helvacioglu-Yigit, Dilek; Aydemir, Seda; Yilmaz, Ayca

    2015-01-01

    The purpose of this study was to evaluate the presence of dentinal defects after root canal preparation with hand instruments and two different reciprocating instruments. Sixty freshly extracted mandibular incisor teeth were selected for this in vitro study. On the basis of root length, mesiodistal and buccolingual dimensions, the teeth were allocated into three identical experimental groups (n = 15) and one control group (n = 15). The teeth in the control group were left unprepared. The other groups were: stainless steel hand instruments, WaveOne® Primary instruments and RECIPROC® R25 instruments. The reciprocating instruments were used with a reciprocating gentle in-and-out motion in a torque-limited electric motor at the appropriate preset mode. Horizontal sections were made 3, 6 and 9 mm from the apex. Samples were stained with methylene blue and viewed through a stereomicroscope. The presence of dentinal defects (fractures, incomplete cracks and craze lines) and their locations were investigated by two endodontists. These data were analysed statistically by Fisher's exact and chi-square tests. No defects were observed in the unprepared group. All instruments caused dentinal defects, with no significant differences between the instrument systems. All experimental groups demonstrated significantly more defects at the 3-mm level in comparison with the unprepared group (p = 0.032). At the other levels, there was no significant difference between the experimental groups and the control group. The use of hand or reciprocating instruments could induce the formation of dentinal defects during root canal preparation. PMID:26019654

  11. A study and analysis of spinal canal diseases in the Black Lion Hospital by Myelography

    International Nuclear Information System (INIS)

    Sixty-seven lumber and thoracic myelographic examinations were performed during the period February 1987 to September 1988. Fourteen patients (21%) had normal myelography while 53 (79%) patients had pathological findings. Spinal canal tumours accounted for the majority of complete CSF blocks (76.7%). Seventy-five per cent of the intradural tumours showed no abnormality on plain films of the vertebral column, whereas 75% of the extradural tumours had pathological findings. Dorsal (central) disc herniation was more frequent (70%) than lateral harniation with almost equal distribution at L5 - S1 and L4 - L5 disc spaces. Central disc herniation was more common at L4 - L5 (71%). The measurement of the interpendicular distance on plain radiography was not found to be diagnostic in our single case of spinal stenosis

  12. Studies on the pathogenesis of degenerative lumbar canal stenosis by computed tomography, 2

    International Nuclear Information System (INIS)

    To evaluate the significance of measurement parameters for the lumbar canal (LC), a retrospective analysis was made of computed tomography (CT) scans in a total of 129 patients, including 20 with degenerative lumbar canal stenosis (DLCS), 65 with degenerative spondylosis, 21 with disc hernia, and 23 with lumbar pain. The shape of the transverse LC was not reflected by the anteroposterior and transverse diameters of LC, but was somewhat reflected by the transverse area of LC. The transverse area of dural sac (DS) was considered important in determining the degree of stenosis. Regarding the transverse area, the DS correlated more strongly with the LC with soft-tissue windows than that with bone windows. The angle of intervertebral joint was likely to be related to the pathophysiology of the LC. In particular, sagittal tendency was seen at the levels of L3-4 and L4-5 in the DLCS group. There was correlation between the angle of intervertebral joint and the transverse areas of both soft-tissue LC and DS at the levels of L4-5. A multivariate analysis suggested the possibility that the significance of measurement parameters might vary depending on the vertebral level for the lower lumbar spine. The following criteria for indicating DLCS were obtained: 1) a transverse area of ≤ 100 mm2 for DS or ≤ 118 mm2 for soft-tissue LC at the levels of L3-4; 2) a transverse area of ≤ 90 mm2 for DS and an angle of ≤ 90 deg for the intervertebral joint at the levels of L4-5; and 3) lateral recess of ≤ 3 mm in anteroposterior diameter at the levels of L5-S1. (Namekawa, K.)

  13. Narrowing of lumbar spinal canal predicts chronic low back pain more accurately than intervertebral disc degeneration: a magnetic resonance imaging study in young Finnish male conscripts.

    Science.gov (United States)

    Visuri, Tuomo; Ulaska, Jaana; Eskelin, Marja; Pulkkinen, Pekka

    2005-11-01

    The objective of this magnetic resonance imaging study was to evaluate the role of degenerative changes, developmental spinal stenosis, and compression of spinal nerve roots in chronic low back (CLBP) and radicular pain in Finnish conscripts. The degree of degeneration, protrusion, and herniation of the intervertebral discs and stenosis of the nerve root canals was evaluated, and the midsagittal diameter and cross-sectional area of the lumbar vertebrae canal were measured in 108 conscripts with CLBP and 90 asymptomatic controls. The midsagittal diameters at L1-L4 levels were significantly smaller in the patients with CLBP than in the controls. Moreover, degeneration of the L4/5 disc and protrusion or herniation of the L5/S1 disc and stenosis of the nerve root canals at level L5/S1 were more frequent among the CLBP patients. Multifactorial analysis of the magnetic resonance imaging findings provided a total explanatory rate of only 33%. Narrowing of the vertebral canal in the anteroposterior direction was more likely to produce CLBP and radiating pain than intervertebral disc degeneration or narrowing of the intervertebral nerve root canals. PMID:16450819

  14. In vitro study of the erbium:yttrium aluminum garnet laser cleaning of root canal by the use of shadow photography

    Science.gov (United States)

    Gregorčič, Peter; Lukač, Nejc; Možina, Janez; Jezeršek, Matija

    2016-01-01

    Erbium:yttrium aluminum garnet laser cleaning is a promising technique in endodontic treatment. In our in vitro study, we measured the vapor-bubble dynamics in the root canal by using shadow photography. The canal model was made of a plastic cutout placed between two transparent glass plates. An artificial smear layer was applied to the glass to study cleaning efficiency. In our results, no shock waves have been observed, since the pulp-chamber dimensions have been in the same range as the maximum diameter of the vapor bubble. This leads to the conclusion that shock waves are not the main cleaning mechanism within our model. However, the cleaning effects are also visible in the regions significantly below the bubble. Therefore, it can be concluded that fluid flow induced by the bubble's oscillations contributes significantly to the canal cleaning. We also proposed a simple theoretical model for cleaning efficiency and used it to evaluate the measured data.

  15. A Study of Measurements of Spinal Canal at the Level of Lower Three Lumbar Vertebra by 16 Slice CT Scanner in Nepalese Population

    OpenAIRE

    Mukesh Mallik; Keshav Paudel; Nuwadatta Subedi; Sanjay Sah; Anish Subedee; Deepak Adhikari

    2015-01-01

    Background and Objective: The study was conducted with the objectives to establish the measurements of spinal canal and lumbar vertebra at L3 to L5 region in Nepalese population. Methodology: It is a cross-sectional study among 36 patients (17 males and 19 females) having age variation from 20-60years whose abdomen was scanned by GE bright speed 16 slice CT scanner with slice thickness 10mm and then reconstructed at 1.2mm for images in different body plains for the measurement of spinal canal...

  16. The effect of body position and axial load on spinal canal morphology: an MRI study of central spinal stenosis

    DEFF Research Database (Denmark)

    Madsen, Rasmus; Jensen, Tue Secher; Pope, Malcolm;

    2007-01-01

    STUDY DESIGN: A method comparison study. OBJECTIVE: To investigate the effect of body position and axial load of the lumbar spine on disc height, lumbar lordosis, and dural sac cross-sectional area (DCSA). SUMMARY OF BACKGROUND DATA.: The effects of flexion and extension on spinal canal diameters...... position with applied axial loading. Disc height, lumbar lordosis, and DCSA were measured and the different positions were compared. RESULTS: In section 1, the only significant difference between positions was a reduced lumbar lordosis during standing when compared with lying (P = 0.04), most probably a...... and DCSA are well documented. However, the effects of axial loading, achieved by upright standing or by a compression device, are still unclear. METHODS: Patients with lumbar spinal stenosis were examined in 2 separate studies, including 16 and 20 patients, respectively. In section 1, magnetic...

  17. Maxillary First Molar with Two Root Canals

    OpenAIRE

    2013-01-01

    Knowledge regarding the anatomic morphology of maxillary molars is absolutely essential for the success of endodontic treatment. The morphology of the permanent maxillary first molar has been reviewed extensively; however, the presence of two canals in a two-rooted maxillary first molar has rarely been reported in studies describing tooth and root canal anatomies. This case report presents a patient with a maxillary first molar with two roots and two root canals, who was referred to the Depar...

  18. Sonic versus ultrasonic activation in calcium hydroxide removal in curved canals: an in-vitro study

    Directory of Open Access Journals (Sweden)

    Tamara Cid.

    2014-12-01

    Full Text Available Resumen: Objetivo: Comparar el área de hidróxido de calcio (Ca(OH2 remanente en el tercio apical de conductos curvos, tras activación sónica y ultrasónica, utilizando Microscopio Electrónico de Barrido (MEB.Metodología: Se recolectaron molares mandibulares permanentes. Se incluyeron los que en la raíz mesial presentron radiográficamente una curvatura entre 15º y 30°. Se instrumentaron 39 conductos mesiolinguales con ProTaper rotatorio y se rellenaron con Ca(OH2 mezclado con propilenglicol. Se dividieron aleatoriamente en 3 grupos de acuerdo al tipo de remoción. Grupo I: tres inserciones con lima F2 irrigando con 2 mL de hipoclorito de sodio (NaOCl 5.25% entre cada inserción. Grupo II: tres activaciones sónicas, irrigando con 2 mL NaOCl 5.25% entre activaciones. Grupo III: tres activaciones Ultrasónicas irrigando con 2 mL NaOCl 5.25% entre activaciones. Se dejaron 3 conductos sin rellenar y otros 3 con relleno total como controles positivo y negativo respectivamente. Luego se fracturaron longitudinalmente obteniendo 2 secciones, se microfotografió el tercio apical del conducto radicular de cada sección con MEB y posteriormente en un área de 100.000 um2, se midió la superficie con Ca(OH2 remanente de ambas secciones usando ImageJ 1.47. Se analizó con ANOVA de una vía usando GraphPad-Prism 5.01.Resultados: El porcentaje de área con Ca(OH2 remanente del grupo I fue 62.93%. Grupo II, 51.77%. Grupo III 58.90%. No hubo diferencia significativa entre los tres grupos (P>0.01Conclusión: No hay diferencias significativas en el porcentaje de área con Ca(OH2 remanente del tercio apical de conductos curvos, al comparar la activación sónica con la ultrasónica, utilizando MEB. Abstract: Objective: Compare the area of calcium hydroxide (Ca(OH2 remaining in the apical third of curved canals after sonic and ultrasonic activation using Scanning Electron Microscope (SEM. Methodology: Permanent mandibular molars were collected. Were

  19. Effect of different final irrigating solutions on smear layer removal in apical third of root canal: A scanning electron microscope study

    OpenAIRE

    Sayesh Vemuri; Sreeha Kaluva Kolanu; Sujana Varri; Ravi Kumar Pabbati; Ramesh Penumaka; Nagesh Bolla

    2016-01-01

    Aim: The aim of this in vitro study is to compare the smear layer removal efficacy of different irrigating solutions at the apical third of the root canal. Materials and Methods: Forty human single-rooted mandibular premolar teeth were taken and decoronated to standardize the canal length to 14 mm. They were prepared by ProTaper rotary system to an apical preparation of file size F3. Prepared teeth were randomly divided into four groups (n = 10); saline (Group 1; negative control), ethyle...

  20. A Study of Measurements of Spinal Canal at the Level of Lower Three Lumbar Vertebra by 16 Slice CT Scanner in Nepalese Population

    Directory of Open Access Journals (Sweden)

    Mukesh Mallik

    2015-07-01

    Full Text Available Background and Objective: The study was conducted with the objectives to establish the measurements of spinal canal and lumbar vertebra at L3 to L5 region in Nepalese population. Methodology: It is a cross-sectional study among 36 patients (17 males and 19 females having age variation from 20-60years whose abdomen was scanned by GE bright speed 16 slice CT scanner with slice thickness 10mm and then reconstructed at 1.2mm for images in different body plains for the measurement of spinal canal. Results: Almost all the parameters increase from L3 to L4 to L5 but the difference is more between L4 and L5 than between L3 and L4 except in vertebral body width (VBW where it increases smoothly, however canal body ratio (CBR remained constant at 0.6. All the parameters were larger in males than in females except antero-posterior dimension of canal in transverse section (APT which is larger in females. It also shows that none of the parameters vary significantly depending upon sex except vertebral body width (VBW at L3 which is 39.041 ± 4.1334 in males and 36.474 ± 2.8509 in females (p=0.036. Conclusion: Antero- posterior dimension in trans-verse and sagittal is almost identical but the chances of measurement error is higher in transverse due to trigonal shape of canal so AP diameter should be done in sagittal section as this is consistent and measures 14mm at L3, 14mm at L4 and 15 mm at L5 hence defining average antero-posterior canal dimension in sagittal section to be 14 mm but CBR constant at 0.6. DOI: http://dx.doi.org/10.3126/jcmsn.v10i4.12971 JCMS Nepal 2014; 10(4:6-11

  1. A comparative study between the efficacy of tramadol, celecoxib and ibuprofen in pain control after root canal therapy of tooth

    Directory of Open Access Journals (Sweden)

    Eshagh A. Saberi

    2011-01-01

    Full Text Available Background: Root canal therapy of teeth can relief the endodontic pain, but post-endodontic pain and discomfort are its undesirable effects. There are many studies on various drugs for alleviation of post-endodontic pain. The aim of this study was to compare the analgesic effect of tramadol, celecoxib and ibuprofen in vital teeth.Materials & Method: In this double blind randomized clinical trial study, 104 patients with vital first mandibular molar tooth were selected. The patients were divided in to four groups, tramadol (A, celecoxib (B, ibuprofen (C and placebo (D. The similar capsules were filled with50mg tramadol HCL, 100mg celecoxib, 400mg ibuprofen and starch . Each patient received randomly one capsule one hour before treatment. If the pain persists, the patient received one tablet of 325 mg acetaminophen every 6 hours. The groups were controlled for 3 days. The data were collected one hour before and 6, 12, 24, 48, 72 hours after treatment. Results were analyzed using kruskal-wallis and Mann-Whitney U tests.Results: The results showed that after 12 (p=0.039 and 24(p=0.024 hours of treatment, tramadol was better in pain relief in comparison with other groups and there was one difference between tramadol and ibuprofen after treatment after 12 hours (p=0.013. But there was no significant deference between drug groups at 6, 48 and 72 hour after treatment.Conclusion: Tramadol prescription in comparison with celecoxib, ibuprofen and placebo has greater analgesic effect after root canal therapy in vital teeth. In addition tramadol may be a good medicine for post-endodontic pain control

  2. A COMPARATIVE STUDY ON THE PRECISION OF THE RADIOLOGICAL AND ELECTRONIC METHODS FOR DETERMINING ROOT CANAL WORKING LENGTHS

    Directory of Open Access Journals (Sweden)

    S. Andrian

    2012-09-01

    Full Text Available The objective of the present investigation was to compare the precision of canal working length (Ll measurements by electronic and radiological methods. Materials and method. The study was developed on a group of 122 anterior teeth of 118 patients, with ages between 23 and 58 years. The teeth were divided into 3 groups. The first one included 45 teeth, for which the working length was calculated with an electronic device (Apex Locator model iPex, NSK, Japan. In the second group of teeth (39 in all, the working length was calculated by the radiographic method of Ingle and, in the third one (38 – by the method of Bregman. When the technique of canal modeling was applied to all groups of teeth, a primary gutta percha cone (master was positioned on the canal at the exact working length calculated for each tooth in part, after which an intra-oral radiography was made and the distance between the apical end of the master cone and the apical constriction was measured. Results. In group I, 91.1% of the Ll measurements were exact, and 8.9% of them were shorter, yet remaining within the limit of 2 mm versus the apical constriction. In group II, 71.7% of Ll were correctly measured, in 5.1% of the cases the calculated length was higher and in 23.2% of them the obtained values led to sub-obturation. Out of the inexact measurements, 44.4% evidenced the tip of the master cone within the limit of 2 mm versus the apical stricture. In group III, 60.5% of the measurements gave exact results, 13.1% of them – higher and 26.4%, respectively – lower. 53.8% of the cases of over- or sub-instrumentations occurred within the limit of 2 mm versus the apical constriction. Conclusions. The method for the calculation of working length with an electronic device of apical localization appeared as the most correct one, being followed by the radiographic technique of Ingle and by the method of Bregman. Application of the electronic method showed no case of apical over

  3. Theoretical studies in nuclear reactions and nuclear structure

    International Nuclear Information System (INIS)

    This report discusses topics in the following areas: Hadronic structure; hadrons in nuclei; hot hadronic matter; relativistic nuclear physics and NN interaction; leptonic emissions from high-Z heavy ion collisions; theoretical studies of heavy ion dynamics; nuclear pre-equilibrium reactions; classical chaotic dynamics and nuclear structure; and, theory of nuclear fission

  4. Assessment of the anterior loop of the mandibular canal: A study using cone-beam computed tomography

    Science.gov (United States)

    do Nascimento, Eduarda Helena Leandro; dos Anjos Pontual, Maria Luiza; dos Anjos Pontual, Andréa; da Cruz Perez, Danyel Elias; Figueiroa, José Natal; Frazão, Marco Antônio Gomes

    2016-01-01

    Purpose Sufficient area in the interforaminal region is required for dental implant placement, and the anterior loop of the mandibular canal is located within the limits of this area. The aim of this study was to evaluate the prevalence and extent of the anterior loop in a Brazilian sample population using cone-beam computed tomography (CBCT). Materials and Methods CBCT images from 250 patients (500 hemimandibles) obtained for various clinical indications were randomly selected and evaluated to determine the presence and length of the anterior loop. The length of the anterior loop was then compared based on gender, age, and the side of the mandible. The data were analyzed using the Pearson chi-square test and linear regression analysis. Results An anterior loop was identified in 41.6% of the cases, and its length ranged from 0.25 mm to 4.00 mm (mean, 1.1±0.8 mm). The loop had a greater mean length and was significantly more prevalent in males (p=0.014). No significant differences were found between the right and left sides regarding length (p=0.696) or prevalence (p=0.650). Conclusion In this study, a high prevalence of the anterior loop of the mandibular canal was found, and although its length varied greatly, in most cases it was less than 1 mm long. Although this is a prevalent anatomical variation, safety limits for the placement of implants in this region cannot be established before an accurate evaluation using imaging techniques in order to identify and preserve the neurovascular bundles. PMID:27358813

  5. Normative structures, collaboration and conflict in irrigation; a case study of the Píllaro North Canal Irrigation System, Ecuadorian Highlands

    NARCIS (Netherlands)

    Hoogesteger van Dijk, J.D.

    2015-01-01

    This paper analyzes conflict and collaboration and their relation to normative structures based on a case study of the history and external interventions of the Píllaro North Canal Irrigation System in the Ecuadorian Highlands. It does so by using Ostrom’s framework for analyzing the sustainability

  6. Two 24-hour Studies of Water Quality in the Ala Wai Canal during March and July, 1994 for the Mamala Bay Study, Pollutant Source Identification Project MB-3, (NODC Accession 0001188)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset focuses on studies of water quality in the Ala Wai Canal in order to determine its role of point and non point source disharge into Mamala Bay. The...

  7. Nuclear materials management storage study

    International Nuclear Information System (INIS)

    The Office of Weapons and Materials Planning (DP-27) requested the Planning Support Group (PSG) at the Savannah River Site to help coordinate a Departmental complex-wide nuclear materials storage study. This study will support the development of management strategies and plans until Defense Programs' Complex 21 is operational by DOE organizations that have direct interest/concerns about or responsibilities for nuclear material storage. They include the Materials Planning Division (DP-273) of DP-27, the Office of the Deputy Assistant Secretary for Facilities (DP-60), the Office of Weapons Complex Reconfiguration (DP-40), and other program areas, including Environmental Restoration and Waste Management (EM). To facilitate data collection, a questionnaire was developed and issued to nuclear materials custodian sites soliciting information on nuclear materials characteristics, storage plans, issues, etc. Sites were asked to functionally group materials identified in DOE Order 5660.1A (Management of Nuclear Materials) based on common physical and chemical characteristics and common material management strategies and to relate these groupings to Nuclear Materials Management Safeguards and Security (NMMSS) records. A database was constructed using 843 storage records from 70 responding sites. The database and an initial report summarizing storage issues were issued to participating Field Offices and DP-27 for comment. This report presents the background for the Storage Study and an initial, unclassified summary of storage issues and concerns identified by the sites

  8. Nuclear materials management storage study

    Energy Technology Data Exchange (ETDEWEB)

    Becker, G.W. Jr.

    1994-02-01

    The Office of Weapons and Materials Planning (DP-27) requested the Planning Support Group (PSG) at the Savannah River Site to help coordinate a Departmental complex-wide nuclear materials storage study. This study will support the development of management strategies and plans until Defense Programs` Complex 21 is operational by DOE organizations that have direct interest/concerns about or responsibilities for nuclear material storage. They include the Materials Planning Division (DP-273) of DP-27, the Office of the Deputy Assistant Secretary for Facilities (DP-60), the Office of Weapons Complex Reconfiguration (DP-40), and other program areas, including Environmental Restoration and Waste Management (EM). To facilitate data collection, a questionnaire was developed and issued to nuclear materials custodian sites soliciting information on nuclear materials characteristics, storage plans, issues, etc. Sites were asked to functionally group materials identified in DOE Order 5660.1A (Management of Nuclear Materials) based on common physical and chemical characteristics and common material management strategies and to relate these groupings to Nuclear Materials Management Safeguards and Security (NMMSS) records. A database was constructed using 843 storage records from 70 responding sites. The database and an initial report summarizing storage issues were issued to participating Field Offices and DP-27 for comment. This report presents the background for the Storage Study and an initial, unclassified summary of storage issues and concerns identified by the sites.

  9. A Study on the Nuclear Foreign Policy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byung Wook; Lee, H. M.; Ko, H. S.; Ryu, J. S.; Oh, K. B.; Yang, M. H.; Lee, K. S

    2007-12-15

    This study approaches the international trends related to nuclear non-proliferation in four aspects. First, this study analyzes the trend of the international nuclear non-proliferation regime, which includes the Treaty on the Non-proliferation of Nuclear Weapons (NPT), the international nuclear export control regime and proposals for assurance of nuclear fuel supply. Second, this study analyzes the trend of international nuclear organizations, which includes the International Atomic Energy Agency (IAEA), a central body of development of nuclear technology and international nuclear diplomacy, and the Organization for Economic Co-operation and Development/Nuclear Energy Agency (OECD/NEA), a intergovernmental organization to consist of a group of nuclear advanced countries. Third, this study analyzes the trends of the U.S.'s nuclear foreign policies, particularly nuclear non-proliferation. Fourth, this study analyzes the nuclear issues of North Korea and Iran as they cause serious concerns to a international society.

  10. Nuclear fuel cycle studies

    International Nuclear Information System (INIS)

    For the metal-matrix encapsulation of radioactive waste, brittle-fracture, leach-rate, and migration studies are being conducted. For fuel reprocessing, annular and centrifugal contactors are being tested and modeled. For the LWBR proof-of-breeding project, the full-scale shear and the prototype dissolver were procured and tested. 5 figures

  11. A comparative evaluation of different irrigation activation systems on smear layer removal from root canal: An in-vitro scanning electron microscope study

    Directory of Open Access Journals (Sweden)

    Nishi Singh

    2014-01-01

    Full Text Available Aim: The aim of the following study is to compare the evaluation of different irrigation activation system-F-File, CanalBrush (CB and EndoActivator (EA in removing smear layer from root canal. Materials and Methods: Root canals of eighty single rooted decoronated premolar teeth were instrumented using crown-down technique and then equally divided into four groups on basis of irrigation activation methods used: Without irrigation - control group, irrigation with F-File, CB, EA into Group I, II, III respectively. Samples were then longitudinally sectioned and examined under scanning electron microscope by three qualified observers using score from 1 to 4. Data was analyzed using Statistical Package for Social Sciences (SPSS, version 15.0 (SPSS Inc., Chicago IL at significance level of P ≤ 0.05. Results: Minimum mean score was observed in Group II at coronal, apical locations. Group III had minimum score at middle third. Groups difference in score were found to be significant statistically for all three locations as well as for overall assessment (P < 0.001. Conclusion: CB remove smear layer more efficiently from the root canal than F-File and EA in coronal and apical region.

  12. Retention of Root Canal Posts

    DEFF Research Database (Denmark)

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

    2015-01-01

    The aim of this study was to investigate the effect of the cement film thickness of a zinc phosphate or a resin cement on retention of untreated and pretreated root canal posts. Prefabricated zirconia posts (CosmoPost: 1.4 mm) and two types of luting cements (a zinc phosphate cement [DeTrey Zinc......] and a self-etch adhesive resin cement [Panavia F2.0]) were used. After removal of the crowns of 360 extracted premolars, canines, or incisors, the root canals were prepared with a parallel-sided drill system to three different final diameters. Half the posts did not receive any pretreatment. The other...... half received tribochemical silicate coating according to the manufacturer's instructions. Posts were then luted in the prepared root canals (n=30 per group). Following water storage at 37°C for seven days, retention of the posts was determined by the pull-out method. Irrespective of the luting cement...

  13. Advanced nuclear systems. Review study

    International Nuclear Information System (INIS)

    The task of this review study is to from provide an overview of the developments in the field of the various advanced nuclear systems, and to create the basis for more comprehensive studies of technology assessment. In an overview the concepts for advanced nuclear systems pursued worldwide are subdivided into eight subgroups. A coarse examination raster (set pattern) is developed to enable a detailed examination of the selected systems. In addition to a focus on enhanced safety features, further aspects are also taken into consideration, like the lowering of the proliferation risk, the enhancement of the economic competitiveness of the facilities and new usage possibilities (for instance concerning the relaxation of the waste disposal problem or the usage of alternative fuels to uranium). The question about the expected time span for realization and the discussion about the obstacles on the way to a commercially usable reactor also play a substantial role as well as disposal requirements as far as they can be presently recognized. In the central chapter of this study, the documentation of the representatively selected concepts is evaluated as well as existing technology assessment studies and expert opinions. In a few cases where this appears to be necessary, according technical literature, further policy advisory reports, expert statements as well as other relevant sources are taken into account. Contradictions, different assessments and dissents in the literature as well as a few unsettled questions are thus indicated. The potential of advanced nuclear systems with respect to economical and societal as well as environmental objectives cannot exclusively be measured by the corresponding intrinsic or in comparison remarkable technical improvements. The acceptability of novel or improved systems in nuclear technology will have to be judged by their convincing solutions for the crucial questions of safety, nuclear waste and risk of proliferation of nuclear weapons

  14. Root canal irrigants

    Directory of Open Access Journals (Sweden)

    Kandaswamy Deivanayagam

    2010-01-01

    Full Text Available 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.

  15. Nuclear spectroscopic studies. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Bingham, C.R.; Guidry, M.W.; Riedinger, L.L.; Sorensen, S.P.

    1994-02-18

    The Nuclear Physics group at UTK is involved in heavy-ion physics including both nuclear structure and reaction mechanisms. During the last year experimental work has been in 3 broad areas: structure of nuclei at high angular momentum, structure of nuclei far from stability, and ultra-relativistic heavy-ion physics. Results in these areas are described in this document under: properties of high-spin states, study of low-energy levels of nuclei far from stability, and high-energy heavy-ion physics (PHENIX, etc.). Another important component of the work is theoretical interpretation of experimental results (Joint Institute for Heavy Ion Research).

  16. Comparison of Bacterial Leakage between 3 Different Root Canal Obturation Techniques in Oval Shaped Canals

    OpenAIRE

    Eshagh-ali Saberi; Shahram Shahraki; Sediqe Ebrahimipour; Anousheh Rashed Mohassel; Narjes Akbari; Majid Rezaei

    2014-01-01

    Introduction: The purpose of this study was to evaluate the sealing ability of 3 obturation techniques in oval-shaped canals by bacterial leakage assessment. Methods: Sixty mandibular incisors with oval canals were selected after providing buccolingual and mesiodistal radiographs. The teeth were sectioned at a 10 mm distance from the apex. After instrumentation, the teeth were divided into 3 groups and the canals in the three groups were obturated with lateral condensation (G1), warm vertical...

  17. Efficacy of etidronic acid, BioPure MTAD and SmearClear in removing calcium ions from the root canal: An in vitro study

    Science.gov (United States)

    Yadav, Hemant Kumar; Tikku, A. P.; Chandra, Anil; Yadav, Rakesh Kumar; Patel, Devendra Kumar

    2015-01-01

    Objective: The purpose of this study was to quantify the amount of calcium ions removed from the root canal by etidronic acid (HEBP), BioPure MTAD, and SmearClear using atomic absorption spectrophotometer. Materials and Methods: Fifty (n = 50) freshly extracted human mandibular premolar teeth were collected and decoronated at the cementoenamel junction. The canals were prepared in a crown down fashion using the rotary system and copiously irrigated with 1.0% sodium hypochlorite. All specimens were rinsed with the deionized water. Based on the type of chelating agent used, the samples (n = 10) were randomly divided into five (four test and one negative control) groups. Accordingly, Group I - 9% HEBP, Group II - 18% HEBP, Group III - SmearClear, Group IV - BioPure MTAD, and Group V - normal Saline. Subsequent to irrigation, the solution was collected in a test tube and subjected to atomic absorption spectrophotometer for the quantification of calcium ions removed from the root canal. Results: The mean concentration of calcium ions removed from the root canal (mean ± standard deviation) in all groups (I–V) were 13.32 ± 0.54 μg/ml, 16.36 ± 0.27 μg/ml, 20.04 ± 0.24 μg/ml, 18.15 ± 0.39 μg/ml, and 8.74 ± 0.49 μg/ml, respectively. Conclusions: SmearClear was the most effective agent for the removal of calcium ions from the root canal. Hence, its combined use with an organic solvent can be recommended for efficient smear layer removal. PMID:26929691

  18. Studying the emerging nuclear suppliers

    International Nuclear Information System (INIS)

    None of these events---nor any of the many others that are cited in the case studies of this book---can be singled out as heralding a revolutionary transformation of the global nuclear marketplace. The cumulative effect of such developments, however, may well be the emergence of a market in the year 2000 that is far less concentrated than today's market for nuclear reactors and fuel cycle technology. If this gradual structural transformation is accompanied by the entry into the market of new buyers and sellers that do not accept the Nuclear Non-Proliferation Treaty (NPT), safeguards administered by the IAEA, or other international norms directed at preventing the spread of nuclear weapon capabilities, the result may indeed have revolutionary dimensions for the business, diplomacy, and research of nuclear energy. A similar outcome could arise even f these norms are widely accepted but are not matched by an increase in the resources available to national governments and key international agencies that implement these norms. This paper identifies some of the pitfalls that researchers often encounter in researching the emerging suppliers and will outline some basic ground rules to guide the collection and interpretation of empirical evidence on supplier behavior

  19. Stratification and enumeration of Boolean functions by canalizing depth

    Science.gov (United States)

    He, Qijun; Macauley, Matthew

    2016-01-01

    Boolean network models have gained popularity in computational systems biology over the last dozen years. Many of these networks use canalizing Boolean functions, which has led to increased interest in the study of these functions. The canalizing depth of a function describes how many canalizing variables can be recursively "picked off", until a non-canalizing function remains. In this paper, we show how every Boolean function has a unique algebraic form involving extended monomial layers and a well-defined core polynomial. This generalizes recent work on the algebraic structure of nested canalizing functions, and it yields a stratification of all Boolean functions by their canalizing depth. As a result, we obtain closed formulas for the number of n-variable Boolean functions with depth k, which simultaneously generalizes enumeration formulas for canalizing, and nested canalizing functions.

  20. [Frequency and most common localisation of root canal curvature].

    Science.gov (United States)

    Blasković-Subat, V

    1991-01-01

    The root canal therapy of the curved canals is a complex operative procedure. Therefore 260 root canals were analysed radiologically to determine the frequency and the most common localisation of the root canal curvature. The frequency of the curved canals averaged at 59%, being greater in the sample of posterior than in the anterior teeth (p less than 0.05). The root canal curvature was most frequently localised at the apical third part (53.9%), followed by the cervical (33.3%) and the middle (12.8%) third part. The apical curvature was predominant in the sample of the anterior, while the cervical predominant (45.2%) in the sample of the posterior teeth. This study pointed out that the frequency of the curved canals is rather high. Consequently, the necessity for practising the modern root canal preparation techniques, bearing in mind their potential danger, is emphasized. PMID:1819932

  1. Stratification and enumeration of Boolean functions by canalizing depth

    CERN Document Server

    He, Qijun

    2015-01-01

    Boolean network models have gained popularity in computational systems biology over the last dozen years. Many of these networks use canalizing Boolean functions, which has led to increased interest in the study of these functions. The canalizing depth of a function describes how many canalizing variables can be recursively picked off, until a non-canalizing function remains. In this paper, we show how every Boolean function has a unique algebraic form involving extended monomial layers and a well-defined core polynomial. This generalizes recent work on the algebraic structure of nested canalizing functions, and it yields a stratification of all Boolean functions by their canalizing depth. As a result, we obtain closed formulas for the number of n-variable Boolean functions with depth k, which simultaneously generalizes enumeration formulas for canalizing, and nested canalizing functions.

  2. Newer Root Canal Irrigants in Horizon: A Review

    OpenAIRE

    Prashant P. Jaju; Sushma Jaju

    2011-01-01

    Sodium hypochloride is the most commonly used endodontic irrigant, despite limitations. None of the presently available root canal irrigants satisfy the requirements of ideal root canal irrigant. Newer root canal irrigants are studied for potential replacement of sodium hypochloride. This article reviews the potential irrigants with their advantages and limitations with their future in endodontic irrigation.

  3. Newer Root Canal Irrigants in Horizon: A Review

    Directory of Open Access Journals (Sweden)

    Sushma Jaju

    2011-01-01

    Full Text Available Sodium hypochloride is the most commonly used endodontic irrigant, despite limitations. None of the presently available root canal irrigants satisfy the requirements of ideal root canal irrigant. Newer root canal irrigants are studied for potential replacement of sodium hypochloride. This article reviews the potential irrigants with their advantages and limitations with their future in endodontic irrigation.

  4. RETRATAMENTO ENDODÔNTICO: ESTUDO COMPARATIVO ENTRE TÉCNICA MANUAL, ULTRA-SOM E CANAL FINDER ENDODONTIC RETREATMENT: COMPARATIVE STUDY BETWEEN MANUAL TECHNIQUE, ULTRASONIC SCALER, AND CANAL FINDER

    Directory of Open Access Journals (Sweden)

    Clovis Monteiro BRAMANTE

    1998-01-01

    Full Text Available Instrumentações manual, ultra-sônica e com Canal Finder foram utilizadas para retratamento de 30 dentes com canais obturados com guta-percha e óxido de zinco e eugenol. Avaliaram-se: 1. tempo gasto para a penetração inicial até o ápice; 2. tempo para completar a limpeza; 3. extrusão de material e 4. limpeza dos canais. O Canal Finder foi a técnica que propiciou melhor limpeza, seguida da manual e da ultra-sônica. A parede palatina do canal foi constantemente mais limpa do que a vestibular. Quanto à extrusão, a técnica de ultra-som foi a que propiciou mais extravasamento de material obturador.Endodontic retreatment of 30 teeth filled with guta percha and zinc oxide-eugenol was carried out using manual instrumentation, ultrasonic scaler, and the Canal Finder System. The following variables were evaluated: time spent to reach the apex; time spent to complete cleaning of the canal; apical extrusion of material; and cleanliness of the canals. Results showed the Canal Finder System as providing the highest level of cleanliness of the canal system; lingual walls were constantly cleaner than buccal walls; ultrasonic technique presented a greater degree of apical extrusion of filling material.

  5. Cultivable Anaerobic Microbiota of Infected Root Canals

    Directory of Open Access Journals (Sweden)

    Takuichi Sato

    2012-01-01

    Full Text Available Objective. Periapical periodontitis is an infectious and inflammatory disease of the periapical tissues caused by oral bacteria invading the root canal. In the present study, profiling of the microbiota in infected root canals was performed using anaerobic culture and molecular biological techniques for bacterial identification. Methods. Informed consent was obtained from all subjects (age ranges, 34–71 years. Nine infected root canals with periapical lesions from 7 subjects were included. Samples from infected root canals were collected, followed by anaerobic culture on CDC blood agar plates. After 7 days, colony forming units (CFU were counted and isolated bacteria were identified by 16S rRNA gene sequencing. Results. The mean bacterial count (CFU in root canals was (0.5±1.1×106 (range 8.0×101–3.1×106, and anaerobic bacteria were predominant (89.8%. The predominant isolates were Olsenella (25.4%, Mogibacterium (17.7%, Pseudoramibacter (17.7%, Propionibacterium (11.9% and Parvimonas (5.9%. Conclusion. The combination of anaerobic culture and molecular biological techniques makes it possible to analyze rapidly the microbiota in infected root canals. The overwhelming majority of the isolates from infected root canals were found to be anaerobic bacteria, suggesting that the environment in root canals is anaerobic and therefore support the growth of anaerobes.

  6. Manual sonic-air and ultrasonic instrumentation of root canal and irrigation with 5.25% sodium hypochlorite and 17% Ethylenediaminetetraacetic acid: A scanning electron microscope study

    OpenAIRE

    Ferit Koçani; Blerim Kamberi; Edmond Dragusha

    2012-01-01

    Objectives: The objective of this study was to evaluate the effectiveness of manual, sonic-air and ultrasonic instrumentation with varying irrigation protocols on removal of the smear layer from root canal walls. Study Design: Sixty extracted single rooted human teeth stored in 0.5% saline were used. Periodontal soft tissues were removed followed by crown separation at the cementoenamel junction (CEJ). All the teeth were randomly divided into three groups. Group I was manually instrumente...

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

    Science.gov (United States)

    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

  8. Comparison of dentinal damage induced by different nickel-titanium rotary instruments during canal preparation: An in vitro study

    Directory of Open Access Journals (Sweden)

    Shiwani Garg

    2015-01-01

    Full Text Available Aim: To compare dentinal damage caused by hand and rotary nickel-titanium instruments using ProTaper, K3 Endo, and Easy RaCe systems after root canal preparation. Materials and Methods: One hundred and fifty freshly extracted mandibular premolars were randomly divided into five experimental groups of 30 teeth each and biomechanical preparation was done: Group 1 with unprepared teeth; Group 2 were prepared with hand files; Group 3 with ProTaper rotary instruments; Group 4 with K3 rotary; Group 5 with Easy RaCe rotary instruments. Then, roots were cut horizontally at 3, 6, and 9 mm from apex and were viewed under stereomicroscope. The presence of dentinal defects was noted. Statistical analysis: Groups were analyzed with the Chi-square test. Results: Significant difference was seen between groups. No defects were found in unprepared roots and those prepared with hand files. ProTaper, K3 rotary, and Easy RaCe preparations resulted in dentinal defects in 23.3%, 10%, and 16.7% of teeth, respectively. More defects were shown in coronal and middle sections, and no defect was seen in apical third. Conclusion: The present study revealed that use of rotary instruments could result in an increased chance for dentinal defects as compared to hand instrumentation.

  9. A Comparative Study on Root Canal Repair Materials: A Cytocompatibility Assessment in L929 and MG63 Cells

    Directory of Open Access Journals (Sweden)

    Yuqing Jiang

    2014-01-01

    Full Text Available Cytocompatibility of repair materials plays a significant role in the success of root canal repair. We conducted a comparative study on the cytocompatibility among iRoot BP Plus, iRoot FS, ProRoot MTA, and Super-EBA in L929 cells and MG63 cells. The results revealed that iRoot FS was able to completely solidify within 1 hour. iRoot BP Plus required 7-day incubation, which was much longer than expected (2 hours, to completely set. ProRoot MTA and Super-EBA exhibited a similar setting duration of 12 hours. All the materials except Super-EBA possessed negligible in vitro cytotoxicity. iRoot FS had the best cell adhesion capacity in both L929 and MG63 cells. With rapid setting, negligible cytotoxicity, and enhanced cell adhesion capacity, iRoot FS demonstrated great potential in clinical applications. Future work should focus on longer-term in vitro cytocompatibility and an in vivo assessment.

  10. Nuclear spectroscopic studies: Progress report

    International Nuclear Information System (INIS)

    The Nuclear Physics Group at the University of Tennessee, Knoxville (UTK) is involved in several aspects of heavy-ion physics including both nuclear structure and reaction mechanisms. While our main emphasis is on experimental problems involving heavy-ion accelerators, we have maintained a strong collaboration with several theorists in order to best pursue the physics of our measurements. During the last year we have led experiments at the Holifield Heavy Ion Research Facility (HHIRF) and the Niels Bohr Institute Tandem Accelerator. Also, we are active in a collaboration (WA80) to study ultra-relativistic heavy ion physics utilizing the SPS accelerator at CERN in Geneva, Switzerland. Our experimental work is four broad areas: (1) the structure of nuclei at high angular momentum, (2) heavy-ion induced transfer reactions, (3) the structure of nuclei far from stability, and (4) ultra-relativistic heavy-ion physics. These results will be described in this document. Areas (1), (3), and (4) concentrate on the structure of nuclear matter in extreme conditions of rotational motion, imbalance of neutrons and protons, or very high temperature and density. Area (2) pursues the transfer of nucleons to states with high angular momentum, both to learn about their structure and to understand the transfer of particles, energy, and angular momentum in collisions between heavy ions. An important component of our program is the strong emphasis on the theoretical aspects of nuclear structure and reactions

  11. Nerve canals at the fundus of the internal auditory canal on high-resolution temporal bone CT

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Yoon Ha; Youn, Eun Kyung; Kim, Seung Chul [Sungkyunkwan Univ., School of Medicine, Seoul (Korea, Republic of)

    2001-12-01

    the canal for the saccular branch. Five bony nerve canals in the fundus of the internal auditory canal were detected by high-frequency on high-resolution temporal bone CT. Familiarity with these structures can prevent confusion with, or misinterpretation as, a fracture line, and further study such as MR imaging may be required when any enlargement or erosion of these nerve canals is present.

  12. Status of nuclear transmutation study

    International Nuclear Information System (INIS)

    JAERI is carrying out R and Ds on partitioning and transmutation under the OMEGA Program. The R and Ds include the design study of accelerator-driven transmutation systems and the development of transmutation experimental facilities. Accelerator-driven systems have received much interests due to their potential role as dedicated transmuters in the nuclear fuel cycle for minimizing long-lived waste. Principles of accelerator-driven system, its history, JAERI proposed system concepts, and the experimental program are overviewed. (author)

  13. Evaluation of biocompatibility of a new root canal irrigant Q Mix TM 2 in 1- An in vivo study

    OpenAIRE

    Veeramachaneni Chandrasekhar; Vanapatla Amulya; Vanapatla Swaroopa Rani; T Jaya Prakash; A Siva Ranjani; Ch Gayathri

    2013-01-01

    Aim: To evaluate the biocompatibility of a new root canal irrigant Q mix™ 2 in 1 in comparison to 0.9% sterile saline, 3% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX), and 17% ethylenediaminetetraacetic acid (EDTA). Materials and Methods: Six circles were drawn on the dorsal skin of 24 male Wistar Albino rats, leaving 2cm between each circle. Using a syringe, 0.1mL of each root canal irrigant was injected subcutaneously into five circles. In the sixth circle, the needle of an empty...

  14. Root canal irrigation

    NARCIS (Netherlands)

    L. van der Sluis; C. Boutsioukis; L.M. Jiang; R. Macedo; B. Verhaagen; M. Versluis

    2015-01-01

    The aims of root canal irrigation are the chemical dissolution or disruption and the mechanical detachment of pulp tissue, dentin debris and smear layer (instrumentation products), microorganisms (planktonic or biofilm), and their products from the root canal wall, their removal out of the root cana

  15. The Root Canal Biofilm

    NARCIS (Netherlands)

    Sluis, van der L.W.M.; Boutsioukis, C.; Jiang, L.M.; Macedo, R.; Verhaagen, B.; Versluis, M.; Chávez de Paz, E.; Sedgley, C.M.; Kishen, A.

    2015-01-01

    The aims of root canal irrigation are the chemical dissolution or disruption and the mechanical detachment of pulp tissue, dentin debris and smear layer (instrumentation products), microorganisms (planktonic or biofilm), and their products from the root canal wall, their removal out of the root cana

  16. Normative structures, collaboration and conflict in irrigation; a case study of the Píllaro North Canal Irrigation System, Ecuadorian Highlands

    OpenAIRE

    Jaime Hoogesteger

    2015-01-01

    This paper analyzes conflict and collaboration and their relation to normative structures based on a case study of the history and external interventions of the Píllaro North Canal Irrigation System in the Ecuadorian Highlands. It does so by using Ostrom’s framework for analyzing the sustainability of socio-ecological systems together with an analysis of the normative structures that define the governance systems through which the interactions in irrigation systems are mediated. I argue that ...

  17. Studies on nuclear reactor design

    International Nuclear Information System (INIS)

    this thesis presents two studies for safety aspects in nuclear reactor design. the fission process that occurs in the reactor core is the most important process for the harmful effect of produced radiation especially neutrons with different energies and gamma radiations for their strong penetrability . so studying the criticality of the fissile materials in the reactor is one of the most important safety aspects for the reactor design, the attenuation of the neutrons and gammas using suitable shielding materials with suitable thicknesses is the second study that is discussed in this thesis

  18. The Dehiscent Facial Nerve Canal

    Directory of Open Access Journals (Sweden)

    Sertac Yetiser

    2012-01-01

    Full Text Available Accidental injury to the facial nerve where the bony canal defects are present may result with facial nerve dysfunction during otological surgery. Therefore, it is critical to know the incidence and the type of facial nerve dehiscences in the presence of normal development of the facial canal. The aim of this study is to review the site and the type of such bony defects in 144 patients operated for facial paralysis, myringoplasty, stapedotomy, middle ear exploration for sudden hearing loss, and so forth, other than chronic suppurative otitis media with or without cholesteatoma, middle ear tumors, and anomaly. Correlation of intraoperative findings with preoperative computerized tomography was also analyzed in 35 patients. Conclusively, one out of every 10 surgical cases may have dehiscence of the facial canal which has to be always borne in mind during surgical manipulation of the middle ear. Computerized tomography has some limitations to evaluate the dehiscent facial canal due to high false negative and positive rates.

  19. A Study on the Nuclear Technology Policy

    International Nuclear Information System (INIS)

    The objective of the study was to make policy-proposals for enhancing the effectiveness and efficiency of national nuclear technology R and D programs. To do this, environmental changes of international nuclear energy policy and trends of nuclear technology development were surveyed and analyzed. This Study analyzed trends of nuclear technology policies and developed the nuclear energy R and D innovation strategy in a viewpoint of analyzing the changes in the global policy environment associated with nuclear technology development and development of national nuclear R and D strategy

  20. Nuclear spectroscopic studies. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Bingham, C.R.; Guidry, M.W.; Riedinger, L.L.; Sorensen, S.P.

    1993-02-08

    The Nuclear Physics group at the University of Tennessee, Knoxville is involved in several aspects of heavy-ion physics including both nuclear structure and reaction mechanisms. While our main emphasis is on experimental problems involving heavy-ion accelerators, we have maintained a strong collaboration with several theorists in order to best pursue the physics of our measurements. During the last year we have led several experiments at the Holifield Heavy Ion Research Facility and participated in others at Argonne National Laboratory. Also, we continue to be very active in the collaboration to study ultra-relativistic heavy ion physics utilizing the SPS accelerator at CERN in Geneva, Switzerland and in a RHIC detector R&D project. Our experimental work is in four broad areas: (1) the structure of nuclei at high angular momentum, (2) heavy-ion induced transfer reactions, (3) the structure of nuclei far from stability, and (4) ultra-relativistic heavy-ion physics. The results of studies in these particular areas will be described in this document in sections IIA, IIB, IIC, and IID, respectively. Areas (1), (3), and (4) concentrate on the structure of nuclear matter in extreme conditions of rotational motion, imbalance of neutrons and protons, or very high temperature and density. Area (2) pursues the transfer of nucleons to states with high angular momentum, both to learn about their structure and to understand the transfer of particles, energy, and angular momentum in collisions between heavy ions. An important component of our program is the strong emphasis on the theoretical aspects of nuclear structure and reactions.

  1. Manual sonic-air and ultrasonic instrumentation of root canal and irrigation with 5.25% sodium hypochlorite and 17% Ethylenediaminetetraacetic acid: A scanning electron microscope study

    Directory of Open Access Journals (Sweden)

    Ferit Koçani

    2012-01-01

    Full Text Available Objectives: The objective of this study was to evaluate the effectiveness of manual, sonic-air and ultrasonic instrumentation with varying irrigation protocols on removal of the smear layer from root canal walls. Study Design: Sixty extracted single rooted human teeth stored in 0.5% saline were used. Periodontal soft tissues were removed followed by crown separation at the cementoenamel junction (CEJ. All the teeth were randomly divided into three groups. Group I was manually instrumented and irrigated with 5.25% sodium hypochlorite (NaOCl alone and 17% Ethylenediaminetetraacetic acid (EDTA alternately, same as sonically instrumented Group II and ultrasonically instrumented Group III. The controls for all groups were irrigated with saline solution. Results: Ultrasonic over the sonic-air and manual technique, and the use of a combination of two different solutions (17% EDTA and 5.25% NaOCl alternatively yielded better outcome. Conclusions: Ultrasonic, sonic-air and manual instrumentation of the root canal and irrigation with combined solutions is effective in removal of the smear layer from the instrumented walls of the root canal.

  2. Removal of Gutta-Percha/Zinc-Oxide-Eugenol Sealer or Gutta-Percha/Epoxy Resin Sealer from Severely Curved Canals: An In Vitro Study

    Directory of Open Access Journals (Sweden)

    Santhoshini Reddy

    2011-01-01

    Full Text Available The aim of this study was to compare the cleanliness of root canal walls after retreatment using two rotary retreatment files to hand instruments in severely curved canals obturated with gutta-percha and two different sealers. Single rooted mandibular premolars (n=90 with root curvatures were instrumented and obturated with gutta-percha and an epoxy resin (Group 1, n=45 or zinc oxide eugenol sealer (Group 2, n=45. Following retreatment of the specimens (n=15 ProTaper Universal Retreatment Files (Subgroup B or R-Endo retreatment files (Subgroup C after 1 month, split specimens were examined under a stereomicroscope and the percentage of remaining root filling material was statistically compared using one way ANOVA with Bonferroni adjustment for multiple comparisons (P=0.05. The R-Endo system performed significantly better than the other two file systems (P<0.05. None of the systems used in this study cleaned root canals thoroughly. The R-Endo system did provide cleaner walls when compared to the other instruments used. The type of root filling materials had an impact on the outcomes with all techniques.

  3. Water pollution control technology and strategy for river-lake systems: a case study in Gehu Lake and Taige Canal.

    Science.gov (United States)

    Zhang, Yimin; Zhang, Yongchun; Gao, Yuexiang; Zhang, Houhu; Cao, Jianying; Cai, Jinbang; Kong, Xiangji

    2011-07-01

    The Taoge water system is located in the upstream of Taihu Lake basin and is characterized by its multi-connected rivers and lakes. In this paper, current analyses of hydrology, hydrodynamics and water pollution of Gehu Lake and Taige Canal are presented. Several technologies are proposed for pollution prevention and control, and water environmental protection in the Taihu Lake basin. These included water pollution control integration technology for the water systems of Gehu Lake, Taige Canal and Caoqiao River. Additionally, river-lake water quality and quantity regulation technology, ecological restoration technology for polluted and degraded water bodies, and water environmental integration management and optimization strategies were also examined. The main objectives of these strategies are to: (a) improve environmental quality of relative water bodies, prevent pollutants from entering Gehu Lake and Taige Canal, and ensure that the clean water after the pre-treatment through Gehu Lake is not polluted before entering the Taihu Lake through Taige Canal; (b) stably and efficiently intercept and decrease the pollution load entering the lake through enhancing the river outlet ecological system structure function and water self-purifying capacity, and (c) designate Gehu Lake as a regulation system for water quality and water quantity in the Taoge water system and thus guarantee the improvement of the water quality of the inflow into Taihu Lake. PMID:21516445

  4. Applying tracer techniques to NPP Cernavoda liquid effluents dispersed in Danube - Black Sea Canal

    International Nuclear Information System (INIS)

    Tritium routinely released as low activity liquid radioactive waste by Cernavoda nuclear power plant was used as a radiotracer to study longitudinal dispersion of Danube Black Sea Canal. A field experiment was carried out in which, after a tritium release, water was sampled downstream from three locations along the canal at periodic intervals. Tritium was measured with a low-background liquid scintillation system and the concentration time evolution for each location was obtained. In order to obtain the canal longitudinal dispersion efficiency, the Unit Peak Attenuation (UPA) curve was plotted. The UPA slope curve was used to construct software that can estimate propagation time of soluble tracer cloud and unit peak attenuation at any location from studied area. (authors)

  5. Root canals decontamination by coherent photons initiated photoacustic streaming (PIPS) of irrigants: an ex-vivo study

    Science.gov (United States)

    Pedullà, E.; Genovese, C.; Scolaro, C.; Cutroneo, M.; Tempera, G.; Rapisarda, E.; Torrisi, L.

    2014-04-01

    The aim of this ex vivo study was to assess the antibacterial effectiveness of coherent photon initiated photoacoustic streaming (PIPS) of irrigants using an Er:YAG laser equipped with a newly designed, stripped and tapered, tip in extracted teeth with infected root canals. One hundred-forty-eight single-rooted extracted teeth were prepared using a rotary abrasive instrument providing a root channel with a suitable size. The samples were sterilized and all teeth except ten (negative control group) were inoculated with Enterococcus faecalis and incubated in a CO2 chamber at 37°C for 15 days in Eppendorff tubes filled with trypticase soy broth medium changed every 2 days. Infected teeth were then randomly divided into 4 test groups (n=32 for each): pulsed erbium:YAG laser at non-ablative settings for 30 seconds with sterile bi-distilled water (Group A) or 5% sodium hypochlorite (NaOCl) (Group B); without laser activated sterile bi-distilled water irrigation for 30 seconds (Group C) or 5% NaOCl irrigation for 30 seconds (Group D); the positive control group received no treatment in infected teeth (n=10). Colony-forming units (CFUs) were counted from bacteriologic samples taken before (S1) and after treatment (S2). Data were analyzed by Kruskal-Wallis and post hoc Dunn's multiple comparison tests. CFU counts were significantly lower in groups B and D than in group C (P0.05). None of the four groups predictably generated negative samples. Under the conditions of this ex vivo study, statistically significant difference wasn't found in planktonic bacteria reduction between the laser and NaOCl or NaOCl alone groups.

  6. Technical quality of root canal fillings performed in a dental school and the associated retention of root-filled teeth: a clinical follow-up study over a 5-year period.

    LENUS (Irish Health Repository)

    Burke, F M

    2009-07-01

    The aim of this study was to examine the technical quality of root canal fillings performed in a dental school and to investigate the associated effect on the survival\\/retention of root-filled teeth. A review of case notes of patients who had root canal treatment performed in the department of Restorative Dentistry, University Dental School and Hospital, Cork, Ireland was carried out. The technical quality of the root canal filling was described according to its relationship with the radiographic apex on a post-treatment radiograph. Tooth status at review was defined as \\'tooth present\\' or \\'tooth absent\\' based on the presence or absence of the root-filled tooth recorded in the treatment records at a review appointment following placement of the root canal filling. One hundred and forty-eight teeth (129 patients) were considered. Of these, 69.6% (n = 103) were of acceptable technical quality, 23.6% (n = 35) were under-extended, and 6.8% (n = 10) were overextended. An increased number of intra-treatment radiographs to confirm the relationship of the canal preparation to the radiographic apex and operator experience were significant predictors of adequate root canal fillings (P < 0.05). Eighty-three per cent (n = 123) of teeth were present at a review appointment held an average of 40 months following completion of treatment (12-60 months). The technical quality of the root canal filling was the only significant factor in predicting tooth survival (P < 0.05), while the presence of pre-treatment periapical pathology had no significant effect on survival of the root-filled tooth. Determination and maintenance of the working length of the canal system is an important feature in producing good quality root canal fillings, which in turn, is associated with increased likelihood of survival\\/retention of root-filled teeth.

  7. Effectiveness of four different final irrigation activation techniques on smear layer removal in curved root canals : a scanning electron microscopy study.

    Directory of Open Access Journals (Sweden)

    Puneet Ahuja

    2014-02-01

    Full Text Available The aim of this study was to assess the efficacy of apical negative pressure (ANP, manual dynamic agitation (MDA, passive ultrasonic irrigation (PUI and needle irrigation (NI as final irrigation activation techniques for smear layer removal in curved root canals.Mesiobuccal root canals of 80 freshly extracted maxillary first molars with curvatures ranging between 25° and 35° were used. A glide path with #08-15 K files was established before cleaning and shaping with Mtwo rotary instruments (VDW, Munich, Germany up to size 35/0.04 taper. During instrumentation, 1 ml of 2.5% NaOCl was used at each change of file. Samples were divided into 4 equal groups (n=20 according to the final irrigation activation technique: group 1, apical negative pressure (ANP (EndoVac; group 2, manual dynamic agitation (MDA; group 3, passive ultrasonic irrigation (PUI; and group 4, needle irrigation (NI. Root canals were split longitudinally and subjected to scanning electron microscopy. The presence of smear layer at coronal, middle and apical levels was evaluated by superimposing 300-μm square grid over the obtained photomicrographs using a four-score scale with X1,000 magnification.Amongst all the groups tested, ANP showed the overall best smear layer removal efficacy (p < 0.05. Removal of smear layer was least effective with the NI technique.ANP (EndoVac system can be used as the final irrigation activation technique for effective smear layer removal in curved root canals.

  8. Comparison of the rheological properties of four root canal sealers

    Institute of Scientific and Technical Information of China (English)

    Seok Woo Chang; Kwang Shik Bae; Young-Kyu Lee; Qiang Zhu; Won Jun Shon; Woo Cheol Lee; Kee Yeon Kum; Seung Ho Baek; In Bog Lee; Bum-Soon Lim

    2015-01-01

    The flowability of a root canal sealer is clinically important because it improves the penetration of the sealer into the complex root canal system. The purpose of this study was to compare the flowabilities of four root canal sealers, measured using the simple press method (ISO 6876), and their viscosities, measured using a strain-controlled rheometer. A newly developed, calcium phosphate-based root canal sealer (Capseal) and three commercial root canal sealers (AH Plus, Sealapex and Pulp Canal Sealer EWT) were used in this study. The flowabilities of the four root canal sealers were measured using the simple press method (n55) and their viscosities were measured using a strain-controlled rheometer (n55). The correlation between these two values was statistically analysed using Spearman’s correlation test. The flow diameters and the viscosities of the root canal sealers were strongly negatively correlated (r520.8618). The viscosity of Pulp Canal Sealer EWT was the lowest and increased in the following order:AH Plus,Sealapex,Capseal (P,0.05). All of the tested root canal sealers showed characteristic time-and temperature-dependent changes in their rheological properties. The viscosities measured using the strain-controlled rheometer were more precise than the flowabilities measured using the simple press method, suggesting that the rheometer can accurately measure the rheological properties of root canal sealers.

  9. Design of canals

    CERN Document Server

    Swamee, P K

    2015-01-01

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

  10. Theoretical studies in nuclear reactions and nuclear structure

    International Nuclear Information System (INIS)

    Research in the Maryland Nuclear Theory Group focusses on problems in four basic areas of current relevance. Hadrons in nuclear matter; the structure of hadrons; relativistic nuclear physics and heavy ion dynamics and related processes. The section on hadrons in nuclear matter groups together research items which are aimed at exploring ways in which the properties of nucleons and the mesons which play a role in the nuclear force are modified in the nuclear medium. A very interesting result has been the finding that QCD sum rules supply a new insight into the decrease of the nucleon's mass in the nuclear medium. The quark condensate, which characterizes spontaneous chiral symmetry breaking of the late QCD vacuum, decreases in nuclear matter and this is responsible for the decrease of the nucleon's mass. The section on the structure of hadrons contains progress reports on our research aimed at understanding the structure of the nucleon. Widely different approaches are being studied, e.g., lattice gauge calculations, QCD sum rules, quark-meson models with confinement and other hedgehog models. A major goal of this type of research is to develop appropriate links between nuclear physics and QCD. The section on relativistic nuclear physics represents our continuing interest in developing an appropriate relativistic framework for nuclear dynamics. A Lorentz-invariant description of the nuclear force suggests a similar decrease of the nucleon's mass in the nuclear medium as has been found from QCD sum rules. Work in progress extends previous successes in elastic scattering to inelastic scattering of protons by nuclei. The section on heavy ion dynamics and related processes reports on research into the e+e- problem and heavy ion dynamics

  11. Nuclear accident dosimetry intercomparison studies.

    Science.gov (United States)

    Sims, C S

    1989-09-01

    Twenty-two nuclear accident dosimetry intercomparison studies utilizing the fast-pulse Health Physics Research Reactor at the Oak Ridge National Laboratory have been conducted since 1965. These studies have provided a total of 62 different organizations a forum for discussion of criticality accident dosimetry, an opportunity to test their neutron and gamma-ray dosimetry systems under a variety of simulated criticality accident conditions, and the experience of comparing results with reference dose values as well as with the measured results obtained by others making measurements under identical conditions. Sixty-nine nuclear accidents (27 with unmoderated neutron energy spectra and 42 with eight different shielded spectra) have been simulated in the studies. Neutron doses were in the 0.2-8.5 Gy range and gamma doses in the 0.1-2.0 Gy range. A total of 2,289 dose measurements (1,311 neutron, 978 gamma) were made during the intercomparisons. The primary methods of neutron dosimetry were activation foils, thermoluminescent dosimeters, and blood sodium activation. The main methods of gamma dose measurement were thermoluminescent dosimeters, radiophotoluminescent glass, and film. About 68% of the neutron measurements met the accuracy guidelines (+/- 25%) and about 52% of the gamma measurements met the accuracy criterion (+/- 20%) for accident dosimetry. PMID:2777549

  12. An in vitro comparison of penetration depth of two root canal sealers: An SEM study

    Directory of Open Access Journals (Sweden)

    Chandra Vijay Singh

    2012-01-01

    Full Text Available Aim: The aim of this study was to examine in vitro penetration depth of two resin-based sealers (AH plus and Resino Seal and Zinc Oxide Eugenol sealer into the dentinal tubules after removing smear layer by passive ultrasonic irrigation. Materials and Methods: Thirty freshly extracted maxillary central incisors were used. The teeth were decoronated, working length established and prepared upto size 40 file. Each root was subjected to passive ultrasonic irrigation with 2.5% sodium hypochlorite. Three different sealers and gutta-percha were used for obturation. Roots were sectioned using hard tissue microtome. These sections were gold sputtered and examined under scanning electron microscope. Results: Statistical analyses of the data were performed using Kruskal-Wallis and Mann-Whitney tests. Statistically significant difference was found between AH Plus sealer and Resino Seal sealer and Zinc Oxide Eugenol sealer. Conclusion: The results showed that AH Plus had maximum penetration depth into dentinal tubules.

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-06-01

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

  15. Analytic studies in nuclear astrophysics

    Science.gov (United States)

    Pizzochero, Pierre

    Five studies are presented in nuclear astrophysics, which deal with different stages of stellar evolution and which use analytic techniques as opposed to numerical ones. Two problems are described in neutrino astrophysics: the solar-neutrino puzzle is analyzed in the framework of the MSW mechanism for the enhancement of neutrino oscillations in matter; and the cooling of neutron stars is studied by calculating the neutrino emissivity from strangeness condensation. Radiative transfer is then examined as applied to SN1987A: its early spectrum and bolometric corrections are calculated by developing an analytic model which can describe both the extended nature of the envelope and the non-LTE state of the radiation field in the scattering-dominated early atmosphere; and a model-independent relation is derived between mass and kinetic energy for the hydrogen envelope of SN1987A, using only direct observations of its luminosity and photospheric velocity. Finally, an analytic approach is presented to relate the softness of the EOS of dense nuclear matter in the core of a supernova, the hydrostatic structure of such core and the initial strength of the shock wave.

  16. Study of canal sediments contaminated with heavy metals: fungal versus bacterial bioleaching techniques.

    Science.gov (United States)

    Sabra, Nada; Dubourguier, Henri-Charles; Duval, Marie-Nadège; Hamieh, Tayssir

    2011-01-01

    Filamentous fungi and lithotrophic bacteria were used to leach heavy metals from dredged sediments in semi-pilot scale air-lift bioreactors. A preliminary physico-chemical characterization of the sediments comprising a sequential extraction study revealed their high metallic contamination and a predominant association of the metals with sulphides and organic matter. The mobility of heavy metals from sediments was ranked by decreasing order as follows: Mn > Zn > Cd > Cu > Pb. The conditions that favoured the solubilization of heavy metals by filamentous fungi turned out to be also favourable for the activity of the sediment organotrophic bacteria. The latter produced organic acids under temporary hypoxic conditions and resulted in the solubilization of 77% of manganese, 44% of zinc, 12% of copper, and less than 2% of cadmium or lead. In general, the fungal organotrophic treatments were limited to the relatively mobile metals due to the weak nature of the organic acids produced and to their microbial consumption under limited saccharose conditions. The lithotrophic treatments yielded higher solubilization results than the organotrophic experiments. Sulphur resulted in a faster, and for some metals such as copper and cadmium, in better bioleaching results compared with reduced iron or with a combination of reduced iron and sulphur. The bioleaching percentages varied between 72 and 93% for cadmium, copper, manganese and zinc, except for lead because of the poor solubility of lead sulphate. The sediment's lithotrophic bacteria acidified the matrix through sulphur oxidation, and leached both loosely and tightly bound metals. PMID:21970173

  17. A report on the aquatic dilution experiment carried out at discharge canal, KGS site

    International Nuclear Information System (INIS)

    Under Nuclear Power Corporation of India Limited (NPCIL), three units of (each of capacity 220MWe) Nuclear Power Stations are operational and one unit of similar capacity is under advanced stage of construction at Kaiga site. The radioactive liquid effluents generated in the plant are diluted with Condenser Coolant Water Stream (CCW) which is then discharged into Kadra reservoir through an artificially made discharge canal. The basic objective of the present study is to estimate the Dilution Factors at various locations of discharge canal and to understand the process of dilution and dispersion of radioactive effluent in the discharge canal. The strategy of the experiment involved the collection of samples from discharge canal lengthwise, breadth wise and depth wise immediately after the routine release of one of the batches of effluent stream into the CCW stream. No additional activity was released for the purpose of this experiment. The study compared the experimentally obtained Dilution Factor with that calculated based on the flow rates of CCW pumps and active liquid effluent discharge pumps. In the present conditions of experiment, Dilution Factor, based on flow rates of CCW pumps and Liquid Effluent Discharge pump, works out to be 8.11 E -05 while experimentally observed Mean Dilution Factor in the discharge canal works out to be (7.75±2.15) E-05. Hence this experiment clearly demonstrate the validity of the method of calculating dilution factor based on the flow rates of CCW line and that of Effluent discharge pump. The data analysis indicates that mass flow seems to be the major process of dispersion in the discharge canal. The tritium activity was found to be moving faster in the midstream as compared to that near the shore. The conclusions are drawn purely based on experimental results. This experimental data can be used for validation of aquatic dispersion models. (author)

  18. Preliminary study on the application of radio-telemetry techniques to evaluate movements of fish in the Lateral canal at Itaipu Dam, Brazil

    Directory of Open Access Journals (Sweden)

    Lisiane Hahn

    2007-01-01

    Full Text Available A preliminary study on the application of radio-telemetry techniques to describe the movements of fish in a bypass channel at Itaipu Dam (Paraná River, known as "Canal da Piracema," was carried out between January and February of 2004. Fourteen individuals of six species (Prochilodus lineatus, Leporinus friderici, Schizodon borellii, Pseudoplatystoma fasciatum, Pterodoras granulosus and Cichla kelberi were intragastrically and surgically radiotagged and monitored by three experimental fixed radio-telemetry stations installed in the upper portion of the Canal. The surgical implantation of transmitters and the anesthesia using clove oil proved to be more efficient and allowed easier handling in comparison to intragastric implantation and electronarcosis immobilization. The use of fixed stations to obtain data was found to be very suitable for tracking movements of several different fish species in the Itaipu lateral channel. Three species (P. granulosus, S. borellii and C. kelberi moved downstream after release. Two individuals of P. fasciatum and two of P. lineatus migrated upstream, leaving the channel 7 and 10 days and 2 and 24 days after release, respectively. Leporinus friderici was the only species that did not leave the release site until the end of the study period.Um estudo preliminar sobre a aplicação de técnicas de radiotelemetria para descrever os movimentos de peixes no canal de transposição da UHE Itaipu (Rio Paraná, conhecido como "Canal da Piracema", foi realizado entre janeiro e fevereiro de 2004. Seis espécies (Prochilodus lineatus, Leporinus friderici, Schizodon borellii, Pseudoplatystoma fasciatum, Pterodoras granulosus e Cichla kelberi totalizando 14 indivíduos foram marcadas com radiotransmissores via cirúrgica e esofágica e rastreados através de três estações fixas experimentais de radiotelemetria instaladas na porção superior do Canal. A implantação de transmissores através de cirurgia e a anestesia por

  19. Mechanics of the Panama Canal slides

    Science.gov (United States)

    Becker, George F.

    1917-01-01

    Dr. Becker visited the Canal Zone in 1913 as a geologist of the United States Geological Survey and since that time has given the problem the benefit of his study. His appointment as a member of the committee of the National Academy of Sciences has made it appropriate for his conclusions, based upon his personal observations and already reported in part to the Canal Commission, to be stated for the benefit of his associates and other American scientists and engineers.

  20. Rapid Quantification of Bacteria in Infected Root Canals Using Fluorescence Reagents and a Membrane Filter: A Pilot Study on Its Clinical Application to the Evaluation of the Outcomes of Endodontic Treatment

    Directory of Open Access Journals (Sweden)

    Takuichi Sato

    2012-01-01

    Full Text Available Objective. The bacterial examination has been performed during the course of the root canal treatment. In the present pilot study, the new developed method, using fluorescence reagents and a membrane filter, was applied to the detection and quantification of bacteria in infected root canals, in order to evaluate the outcomes of the treatment. Methods. Six infected root canals with periapical lesions from 5 subjects were included. Informed consent was obtained from all subjects (age ranges, 23–79 years. Samples from infected root canals were collected at the beginning of the treatment (termed #25 First, the end of the first day of treatment (termed #55 First, and the next appointment day (termed #55 Second. Then, the bacterial count (CFU was measured using fluorescence reagents (4′,6′-diamidino-2-phenylindole and propidium iodide and the polycarbonate membrane filter by Bioplorer. Results. The mean ± SD of CFU in the sample of “#25 First” was (1.0±1.4×105. As the root canal treatment progressed, the CFU decreased as 7.9×103 (#55 First and 4.3×102 (#55 Second. Conclusion. In the present pilot study, rapid detection and quantification of bacteria in infected root canals were found to be successfully performed using fluorescence reagents and a membrane filter (Bioplorer analysis.

  1. Estudo comparativo de aspectos histológicos e imunohistoquímicos entre o colesteatoma espontâneo do meato acústico externo e o colesteatoma adquirido da orelha média Comparative study of the histological and immunohisochemical aspects of the spontaneous cholesteatomas of the external ear canal and the acquired cholesteatoma of the middle ear

    Directory of Open Access Journals (Sweden)

    Fernando de Andrade Quintanilha Ribeiro

    2004-10-01

    ear was carried out. STUDY DESIGN: Case-control. MATERIAL AND METHOD: Fragments of external ear canal cholesteatomas were submitted to histological and immunohistochemical studies to evaluate the expression of CK-16 and of the nuclear antigen Ki-67 in the matrix cells. Results were compared to the same studies in acquired cholesteatomas of the middle ear. RESULTS: Histological and immunohistochemical aspects studied were identical in both types of cholesteatomas studied. DISCUSSION: This study suggests that cholesteatomas of the external ear canal are caused by na abnormal behavior of the cells of the epithelium of the external canal with hyperproliferative properties. This potential could be explained by the presence of CK-16 at a location where these markers are not usually found. The hyperproliferative characteristic of the external ear canal cholesteatoma is possible due to the presence of the K-67 nuclear antigen in the epidermal suprabasal cells. It is possible that the disease is caused by an interaction between CK-16 and the cytocines (TGF-alpha,which are present in the subepithelial connective tissue undergoing na inflammatory process. CONCLUSIONS: The histological (presence of epithelial cones and immunohistochemical (expression of CK 16 and the nuclear antigen KI-67 characteristics of both the external ear canal and the acquired middle ear cholesteatomas are identical.

  2. Root canals decontamination by coherent photons initiated photoacustic streaming (PIPS) of irrigants: an ex-vivo study

    International Nuclear Information System (INIS)

    The aim of this ex vivo study was to assess the antibacterial effectiveness of coherent photon initiated photoacoustic streaming (PIPS) of irrigants using an Er:YAG laser equipped with a newly designed, stripped and tapered, tip in extracted teeth with infected root canals. One hundred-forty-eight single-rooted extracted teeth were prepared using a rotary abrasive instrument providing a root channel with a suitable size. The samples were sterilized and all teeth except ten (negative control group) were inoculated with Enterococcus faecalis and incubated in a CO2 chamber at 37°C for 15 days in Eppendorff tubes filled with trypticase soy broth medium changed every 2 days. Infected teeth were then randomly divided into 4 test groups (n=32 for each): pulsed erbium:YAG laser at non-ablative settings for 30 seconds with sterile bi-distilled water (Group A) or 5% sodium hypochlorite (NaOCl) (Group B); without laser activated sterile bi-distilled water irrigation for 30 seconds (Group C) or 5% NaOCl irrigation for 30 seconds (Group D); the positive control group received no treatment in infected teeth (n=10). Colony-forming units (CFUs) were counted from bacteriologic samples taken before (S1) and after treatment (S2). Data were analyzed by Kruskal-Wallis and post hoc Dunn's multiple comparison tests. CFU counts were significantly lower in groups B and D than in group C (P<0.001). Moreover, there was a significant difference between Group A and C (P<0.001). Group B showed the highest CFU reduction, which was significantly greater than that evident in groups A or C (P<0.001). There were no statistically significant differences between group B and D (P>0.05). None of the four groups predictably generated negative samples. Under the conditions of this ex vivo study, statistically significant difference wasn't found in planktonic bacteria reduction between the laser and NaOCl or NaOCl alone groups.

  3. 下颌第二恒磨牙根管系统的形态学研究%Morphological studies on the root canals of mandibular second molars

    Institute of Scientific and Technical Information of China (English)

    周春飞; 冯坤

    2012-01-01

    目的 了解下颌第二恒磨牙牙根及根管的类型,为提高根管治疗的效果提供解剖学依据.方法 收集682例离体下颌第二恒磨牙,进行牙体测量,透明牙标本制作,分别对牙根及根管系统进行研究.结果 682例离体牙中双根牙最多,占55.13%(376/682),其中97例为C形根管,占14.22%.除外97例C形根管,585例离体牙的7种不同类型根管中,1-1型、2-1型、2-2型最多,近中根为85.64%(501/585),远中根为96.75%(566/585);近中根中双根管或单双根管混合型占72.14%(422/585),远中根中占18.29%(107/585);近中根的双根管口率为60.00%(351/585),远中根为15.73%(92/585);近中根的双根尖孔率为35.21%(206/585),远中根为13.50%(79/585).根管侧支、管间侧支、根尖分叉的出现率分别为24.19%(165/682)、22.14%(151/682)和8.21%(56/682).55.76%(416/746)的近中根根尖孔位于根尖顶,57.85%(383/662)的远中根根尖孔位于根尖顶.结论 下颌第二恒磨牙根管的类型复杂,充分了解其根管解剖对提高根管治疗效果、减少根管遗漏有重要意义.%Objective To study the types of dental root and root canal of mandibular second molars so as to provide anatomical evidence for root canal therapy. Methods A total of 682 well-developed mandibular second molars were examined after decalcifying and clearing technique. Results 55.13% (376/682) of the 682 mandibular second molars had two roots. C-shaped canal system was found in 97 teeth (14.22%). Among seven categories of canal systems in the other 585 teeth, type 1-1, type 2-1 and type 2-2 were found commonly, with the incidence being 85.64% (501/585) in mesial roots and 96.75% (566/585) in distal roots. Double-canal type or the mixed form was examined in 72. 14% (422/585) of mesial roots and 18.29% (107/585) of distal roots. 60.00% (351/585) of mesial roots had double canal orifices and 35.21% (206/585) had two apical foramens, while 15.73% (92/585) of distall roots

  4. A Study on the Nuclear Foreign Policy

    International Nuclear Information System (INIS)

    In this study, the changes in international nuclear environments related to nuclear non-proliferation regimes and international nuclear cooperation activities are investigated in order to suggest recommendations for actions and measures in the national policy of Korea, focusing on the trends for strengthening international nuclear non-proliferation regimes, international discussions of multi-lateral fuel supply assurances, USA nuclear energy policy and nuclear cooperation between USA and India. International nuclear non-proliferation regime is expected to be continuously strengthened during the 21st century. Assurance of a fuel supply is a critical issue in the national nuclear power industry of Korea due to a complete dependency of its uranium enrichment services on foreign countries and the declaration of a non-possession of facilities for a uranium enrichment and nuclear reprocessing in Korea. Nuclear energy is indispensable for a national energy security and securing a competitive power of nuclear technologies, and the development and export of nuclear industry products are also very important. It is recommended to strengthen the international cooperation and diplomatic efforts of Korea for protecting the national interests in the international nuclear communities and enhancing for a national power supply as well as securing of confidence and transparency of the national nuclear policy and relevant activities

  5. A study on the nuclear technology policy

    International Nuclear Information System (INIS)

    This study was carried out as a part of institutional activities of KAERI. This study suggested the effective and systematic alternatives for the development of domestic industry through nuclear long-term R and D program while timely responding to the environmental change in local and global sense. First of all, this study investigated the current status and prospect of nuclear power supply, the global technological change of nuclear fuel cycle, the nuclear policy changes of major countries and the role of nuclear energy in East Asian countries. Second, some policy alternatives are suggested in association with the role of national R and D in enhancing industrial competitiveness, the effective management of nuclear long-term R and D program to facilitate technological innovation and the way to enlarge the utilization of nuclear R and D results and radiation technology

  6. Nuclear communication management. Case study: the Nuclear Agency of Cuba

    International Nuclear Information System (INIS)

    The development of the science is a hallmark of our time. Thousands of products, processes and services incorporated into daily newspaper innovations that are result of basic and applied research. A primary mechanism of existence and development of the science is the communication of its results, in both disclose, transmit and validate the science allows. For an institution in the sector nuclear is doubly important due to the ignorance of the technology and the public perception that it generates. The study responds to the need of the Nuclear Energy Agency and Advanced technologies to manage the communication of their activities and increase the visibility of their results in science and innovation. In response to the approach of the problem assessed the management of the communication of the agency taking into account four nuclear activity basic elements: the existence of policies, training, assessment or diagnosis and planning. The diagnosis of internal and external communication It was through a study of image. For the diagnosis was developed a method, from those used internationally for imaging studies. The results of the diagnostic allowed to conclude that insufficient visibility of the nuclear activity of the AENTA is due to internal and external factors related to communication. The study allowed to design a communication strategy for the Agency's Nuclear energy and advanced technologies for nuclear activities and develop a methodological proposal for the design of strategies of communication with the Agency. (author)

  7. Transcranial bright light treatment via the ear canals in seasonal affective disorder: a randomized, double-blind dose-response study

    OpenAIRE

    Jurvelin, Heidi; Takala, Timo; Nissilä, Juuso; Timonen, Markku; Rüger, Melanie; Jokelainen, Jari; Räsänen, Pirkko

    2014-01-01

    Background Bright light treatment is effective for seasonal affective disorder (SAD), although the mechanisms of action are still unknown. We investigated whether transcranial bright light via the ear canals has an antidepressant effect in the treatment of SAD. Methods During the four-week study period, 89 patients (67 females; 22 males, aged 22-65, mean ± SD age: 43.2 ± 10.9 years) suffering from SAD were randomized to receive a 12-min daily dose of photic energy of one of three intensities ...

  8. A Study on the Nuclear Technology Policy

    International Nuclear Information System (INIS)

    The objective of the study was to make policy-proposes for enhancing the effectiveness and efficiency of national nuclear technology development programs. To do this, changes of international nuclear energy policy environment and trends of nuclear technology development was surveyed and analyzed. In the viewpoint of analysis of the changes in the global policy environment surrounding nuclear technology development and development of national nuclear R and D strategy, this study (1) analyzed trends of nuclear technology policies and (2) developed the nuclear energy R and D innovation strategies. To put it in more detail, each subject was further explored as follows; (1) themes to analyze trends of nuclear policies: nuclear Renaissance and forecast for nuclear power plant, International collaboration for advanced nuclear technologies in GIF, INPRO and I-NERI, The present situation and outlook for world uranium market (2) themes to develop of nuclear energy R and D innovation strategies: The mid-term strategy plan of the KAERI, The technological innovation case of the KAERI

  9. A Study on the Nuclear Technology Policy

    Energy Technology Data Exchange (ETDEWEB)

    Kim, H. J.; Lim, C. Y.; Yang, M. H. (and others)

    2008-03-15

    The objective of the study was to make policy-proposes for enhancing the effectiveness and efficiency of national nuclear technology development programs. To do this, changes of international nuclear energy policy environment and trends of nuclear technology development was surveyed and analyzed. In the viewpoint of analysis of the changes in the global policy environment surrounding nuclear technology development and development of national nuclear R and D strategy, this study (1) analyzed trends of nuclear technology policies and (2) developed the nuclear energy R and D innovation strategies. To put it in more detail, each subject was further explored as follows; (1) themes to analyze trends of nuclear policies: nuclear Renaissance and forecast for nuclear power plant, International collaboration for advanced nuclear technologies in GIF, INPRO and I-NERI, The present situation and outlook for world uranium market (2) themes to develop of nuclear energy R and D innovation strategies: The mid-term strategy plan of the KAERI, The technological innovation case of the KAERI.

  10. Radiographic study of the sound navicular bone. Part 1: What about the canals on the distal border

    International Nuclear Information System (INIS)

    The scoring system based on the different types of navicular distal border canals is a good method to quantify and relativise the anomalies in number, shape and localisation of the canals. The distal border score varies significantly with the limb (fore or rear), the morphological type, the gender and the age of the horse. These anatomical variations are of importance and must be taken into account when examining a suspect bone. The score is larger for the fore navicular bone than for the rear. It could be interesting to compare both scores: rear navicular bone score is generally equal to half (or slight less) that of the fore. The score is larger for heavy types of horses and ponies (drafthorse, heavy halfbreds and Fjords). This phenomenon could be related to a larger pressure within the distal interphalangeal joint. The score is lower for the athletic halfbred than for other half-breds. This could be the result of the changes in bone architecture induced by exercise and particularly bone densification. The score is lower for the female than for the male. We think that navicular bone quality is better for the female and this idea corroborates that of other authors that consider that the risk to develop navicular disease is smaller for the female than for the male. The score increases with age. It is particularly small in young horses less than two years old and then increases strongly. This phenomenon is to be related to the progressive development, in the first year of life, of the groove between articular cartilage and distal impar ligament, canals developping only later one. In athletic horses, the score is higher between 7 and 12 years of age. During this time, we also observe more degenerative changes within the navicular bone, which could mean that bone is of lesser quality

  11. Studies on biomarkers of oxidative stress and associated genotoxicity and histopathology in Channa punctatus from heavy metal polluted canal.

    Science.gov (United States)

    Javed, Mehjbeen; Ahmad, Irshad; Usmani, Nazura; Ahmad, Masood

    2016-05-01

    Some investigations were made on the Satha canal water and health of dwelling fish Channa punctatus at Satha village, district Aligarh (U.P). Metal bioaccumulation and induction of biomarkers such as lipid peroxidation (LPO), superoxide dismutase (SOD), catalase (CAT), glutathione S transferase (GST), reduced glutathione (GSH), DNA damage and histopathology are potential indicators of stress in C. punctatus exposed to effluents. In canal water Cr, Mn, Fe and Ni concentrations were exceeding the permissible limits set by both Bureau of Indian standards (BIS) and WHO. Fe (74%) was highly bioavailable and accumulated in all organs (gill, liver, kidney, muscle and integument). The highest metal pollution index (MPI) value of 53 was observed in gills and the lowest 6 in liver tissue. SOD and LPO were significantly higher in all tissues, whereas CAT, GST and GSH levels declined significantly compared to fish from the reference site. Concomitant damage to DNA was observed with significantly higher mean tail length in the exposed fish gill cells (19 μm) and in liver (12.7 μm) compared to reference fish (5 and 4 μm respectively). Histopathology in gill and liver also show significant damage. Therefore, it can be concluded that the sugar mill effluent has the potential to cause oxidative stress, DNA damage and histopathology in C. punctatus. This canal is a prime source of water and fish food to the local residents of the area. Therefore, the consumers may suffer adverse health effects like that in indicator organism. PMID:26943742

  12. Canals, River Irrigation Company Canal, Published in 2002, Duchesne County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Canals dataset, was produced all or in part from Other information as of 2002. It is described as 'River Irrigation Company Canal'. Data by this publisher are...

  13. Canals, Yellowstone Feeder Canal, Published in 2002, Duchesne County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Canals dataset, was produced all or in part from Other information as of 2002. It is described as 'Yellowstone Feeder Canal'. Data by this publisher are often...

  14. Canals, Dry Gulch Canal, Published in 2002, Duchesne County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Canals dataset as of 2002. It is described as 'Dry Gulch Canal'. Data by this publisher are often provided in UTM coordinate system; in a Transverse Mercator...

  15. Canals, Lake Canal, Published in 2002, Duchesne County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Canals dataset, was produced all or in part from Other information as of 2002. It is described as 'Lake Canal'. Data by this publisher are often provided in...

  16. Canals, Little Blackhawk Canal, Published in 2002, Duchesne County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Canals dataset, was produced all or in part from Other information as of 2002. It is described as 'Little Blackhawk Canal'. Data by this publisher are often...

  17. Effectiveness of four different techniques in removing intracanal medicament from the root canals: An in vitro study

    OpenAIRE

    A C Bhuyan; Mukut Seal; Kartik Pendharkar

    2015-01-01

    Aim: To evaluate the effectiveness of different techniques in removing calcium hydroxide (Ca(OH) 2 ) from the root canal. Materials and Methods: Twenty-four freshly extracted mandibular premolars were instrumented using ProTaper rotary instruments. The teeth were longitudinally split into two halves, cleaned of debris. The two halves were then reassembled and filled with Ca(OH) 2 and were divided into four groups. In Group I, the teeth were irrigated with 5 mL of 2.5% sodium hypochlorite (NaO...

  18. A study on the nuclear technology policy

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Maeng Ho; Eom, T. Y.; Ham, C. H.; Kim, H. J.; Chung, W. S.; Lee, T. J.; Lee, B. O.; Yun, S. W.

    1997-01-01

    Work scopes and major contents carried out by nuclear technology policy analysis project in 1996, are as follows: First, reviews and provisions of recommendations for the revision draft of Atomic Energy Act, the national long-tem plan of use and development of nuclear technologies forward the 21st century, and KAERI vision for the next 10 years have been undertaken as parts of division`s role to support the implementation and set-up of national nuclear policy. Second, the trends of nuclear policy, research and development activities of nuclear institutes and the nuclear industries of the major advanced countries, were analyzed. Nuclear development trends in the East-Asia region emerging as a new nuclear market in the near future, were also analyzed including China. Finally, as the research works for the development of nuclear technology policy, a comparative analyses of the forecasted future nuclear technologies of nuclear advanced countries and a study for the improvement of spin-off effectiveness of nuclear research and development activities were undertaken respectively. (author). 19 refs., 29 tabs., 19 figs.

  19. Comprehensive Immunolocalization Studies of a Putative Serotonin Receptor from the Alimentary Canal of Aedes aegypti Larvae Suggest Its Diverse Roles in Digestion and Homeostasis.

    Science.gov (United States)

    Petrova, Adelina; Moffett, David Franklin

    2016-01-01

    Serotonin regulates key processes including digestion and homeostasis in insects. Serotonin effects are mediated by serotonin receptors that transduce information through initiation of second messenger signaling pathways. Lack of information on serotonin receptors associated with the alimentary canal impedes the understanding of the serotonergic role in insect physiology. To address this void, the present study has cloned and identified a putative serotonin receptor (hereafter AaSeR-1) from the alimentary canal of Aedes aegypti (yellow fever mosquito) larvae. In addition to in-silico analyses of AaSeR-1 primary sequence, immunohistochemical investigations were carried out to elucidate receptor expression patterns. Specific AaSeR-1 immunofluorescence was detected in the caeca, the mid- and hindgut, including the Malpighian tubules. These findings point out not only receptor ubiquitous nature but also its involvement in regulation of different stages of nutrient processing and homeostasis. Furthermore, AaSeR-1 may mediate an array of effects through its differential expression at various cell compartments. While AaSeR-1 specific immunofluorescence was depicted in the nucleus and nucleolus of principal cells of the anterior midgut, in the posterior, analyses suggest receptor association with the plasma membrane of both principal and regenerative cells. In addition, AaSeR-1 immunofluorescence was also found in some enteroendocrine cells and in both circular and longitudinal muscles that innervate the alimentary canal. Overall, immunohistochemical analyses of AaSeR-1 expression indicate that this receptor exercises multiple roles in digestion- and homeostasis-related mechanisms. PMID:26808995

  20. Ear canal cholesteatoma.

    Science.gov (United States)

    Holt, J J

    1992-06-01

    Although cholesteatomas are more commonly found in the middle ear and the mastoid, the disease can occur in the external ear canal. All cases of ear canal cholesteatoma treated by the author were reviewed. There were nine ears in seven patients, who had an average age of 62 years. The lesions ranged in size from a few millimeters to extensive mastoid destruction. Smaller lesions can be managed by frequent cleaning as an office procedure. Larger lesions require surgery, either canaloplasty or mastoidectomy. The otolaryngologist should suspect this disease in the elderly. Microscopic examination of the ear with meticulous cleaning of all wax, especially in elderly patients, is most useful in detecting early disease. Frequent applications of mineral oil to the canal should be used in the management of the disease and to prevent recurrence. PMID:1376388

  1. Study of nuclear data and applied nuclear physics at the Dalat Institute for Nuclear Research (Vietnam)

    International Nuclear Information System (INIS)

    The Dala Institute for Nuclear Research (DINR) is the main nuclear research establishment of Vietnam National Atomic Energy Commission (VINATOM). The activity of DINR in neutron activation analysis (NAA), radioisotope production and radiation technology has begun since 1980s using nuclear reactor and Co-60 radiation source. The safe operation and efficient exploitation of the Dalat nuclear reactor have required researches on nuclear data and reactor physics. This report presents study of nuclear data and applied nuclear physics at the Dalat Institute for Nuclear Research using filtered neutron beams and the thermal column of the reactor. The information presented is based mainly on the results of the National Research Contracts 50A-01-01-03, KT-04-3.2.3 and KC-09-08 for the period 1985-1995. (author). 28 refs, 17 figs, 3 tabs

  2. Reduction of Enterococcus faecalis in curved root canals after various sizes and tapers of canal preparation

    OpenAIRE

    Amir Abbas Moshari; Nahid Mohammadzadeh Akhlaghi; Nahid Rahimifard; Soheila Darmiani

    2015-01-01

    Aims: The aim of this study was to evaluate the reduction of Enterococcus faecalis in curved root canals after various sizes and tapers of the canal preparation. Materials and Methods: Mandibular first molars (n = 103) with curved mesiobuccal canals were divided into one control (n = 5) and 7 experimental (n = 14) groups, were inoculated with E. faecalis (ATTC 29212) and prepared with the following RaCe files (FKG Dentaire) as master apical file: Groups: 25.04, 25.06, 30.04, 30.06, 35.04,...

  3. 77 FR 18271 - Terrestrial Environmental Studies for Nuclear Power Stations

    Science.gov (United States)

    2012-03-27

    ... COMMISSION Terrestrial Environmental Studies for Nuclear Power Stations AGENCY: Nuclear Regulatory Commission... revision to Regulatory Guide (RG) 4.11, ``Terrestrial Environmental Studies for Nuclear Power Stations... environmental studies and analyses supporting licensing decisions for nuclear power reactors. ADDRESSES:...

  4. Facial nerve canal dehiscence in chronic otitis media without cholesteatoma

    OpenAIRE

    Nomiya, Shigenobu; Kariya, Shin; Nomiya, Rie; MORITA, NORIMASA; Nishizaki, Kazunori; Paparella, Michael M.; Cureoglu, Sebahattin

    2013-01-01

    The information on incidence of the facial nerve canal dehiscence in chronic otitis media is important for surgeons. The purpose of this study is to disclose the histopathologic findings of facial nerve canal dehiscence in human temporal bones with chronic otitis media. We divided the human temporal bones into two groups (age 4 years, and under 4 years of age). We evaluated the incidence and the area of the facial nerve canal dehiscence in chronic otitis media under light microscopy. Age-matc...

  5. Interactions between root canal irrigants, sealers and dentin

    OpenAIRE

    Neelakantan, P.

    2016-01-01

    The objective of this thesis was to determine the interactions between root filling materials and root dentin and to investigate if root canal irrigating solutions had an impact on these interactions. The following outcomes were assessed in the studies encompassed in this thesis: (i) dislocation resistance of an epoxy resin based root canal sealer and tricalcium silicate based root canal sealers, (ii) the influence of irrigation protocols on the sealing ability and chemical interactions with ...

  6. Endodontic Considerations in Three-canalled Premolars: A Practical Update.

    Science.gov (United States)

    Mohammadi, Zahed; Shalavi, Sousan; Giardino, Luciano; Asgary, Saeed

    2016-01-01

    The most difficult clinical considertions in orthograde root canal treatment are generally related to the anatomy of the teeth. Three-canalled maxillary and mandibular premolars (mini-molars) have been reported in several studies. The purpose of this paper was to review various aspects of three-canalled premolars including incidence, clinical and radiographic diagnosis, racial predisposition, access cavity preparation, instrumentation and obturation. PMID:27141223

  7. To evaluate the influence of smear layer with different instruments and obturation methods on microleakage of root canal filled teeth: In vitro study

    Science.gov (United States)

    Likhitkar, Manoj S.; Kulkarni, Shantaram V.; Burande, Aravind; Solanke, Vishal; Kumar, C. Sushil; Kamble, Babasaheb

    2016-01-01

    Aims and Objectives: The success of root canal treatment depends on proper debridement, instrumentation, proper accessibility, and proper restoration. The presence of a smear layer is considered to be a significant factor. This in vitro study was conducted to assess the effect of the presence/absence of a smear layer on the microleakage of root canal filled teeth using different instruments and obturation methods. Materials and Methods: One hundred extracted mandibular premolars with closed apices and single roots were chosen and then divided into six groups, A to F, consisting of 15 teeth each. The control group included 10 teeth; 5 positive and 5 negative. The teeth were decoronated at the cementoenamel junction. Groups A, B, C, and D were instrumented with engine-driven rotary Protaper NiTi files. Groups E and F were instrumented with conventional stainless steel hand files. Groups A, C, and E were flushed with 3 ml of 17% EDTA to remove the smear layer prior to obturation. All teeth were flushed with 5.25% sodium hypochlorite solution and obturated with AH-Plus sealer with lateral condensation technique for Groups C, D, E, F and with thermoplasticized gutta-percha technique for Groups A and B. Using an electrochemical technique, leakages in the obturated canals were assessed for 45 days. The results were tabulated using Student's t-test (paired and unpaired t-test) with the Statistical Package for the Social Sciences Software Version 21 (IBM Company, New York, USA). Results: Group A showed the lowest mean value at intervals of 10, 20, 30, and 45 days. There was no current flow in the negative controls during the test period. There was leakage in the positive controls within a few minutes of immersion. Conclusion: The results showed that rotary instrumentation contributed toward an exceptional preparation of root canals compared to hand instrumentation. Elimination of the smear layer enhanced the resistance to microleakage; thermoplasticized gutta

  8. Sonic versus ultrasonic activation for the cleaning of the root canal after post space preparation: an in vitro study.

    Directory of Open Access Journals (Sweden)

    René Carrasco

    2015-08-01

    Full Text Available Objective: To compare the efficacy of 3 intracanal cleaning protocols used before cementation of prosthetic posts. Material and Methods: 40 anterior teeth received endodontic treatment in hand, using lateral condensation technique. After two weeks, gutta-percha was appropriately removed from the teeth to get the necessary space to install a post. Then, teeth were randomly divided into groups; root surface was treated with chlorhexidine (CHX activated by ultrasound (US (group I, with chlorhexidine activated by sonic instrumentation (S (group II, chlorhexidine without activation (group III and without treatment (group IV. All teeth were fractured longitudinally getting 2 sections. The middle third of the root canal was microphotographed with a scanning electron microscope (SEM and the contaminated surface was measured using detritus with ImageJ 1.47. It was analyzed with Kruskal-Wallis-test using GraphPad Prism 5.01. Results: The median percentage of contaminated area of Group I was 20.06%, Group II, 19.3%; Group III, 36.05%; and Group IV, 56.45%. Conclusion: There are significant differences among different intracanal cleaning protocols in the removal efficiency of detritus from the root canal, being the activated protocols the most effective ones.

  9. Spinal canal stenosis

    International Nuclear Information System (INIS)

    Spinal stenosis is a narrowing of the spinal canal by a combination of bone and soft tissues, which can lead to mechanical compression of spinal nerve roots or the dural sac. The lumbal spinal compression of these nerve roots can be symptomatic, resulting in weakness, reflex alterations, gait disturbances, bowel or bladder dysfunction, motor and sensory changes, radicular pain or atypical leg pain and neurogenic claudication. The anatomical presence of spinal canal stenosis is confirmed radiologically with computerized tomography, myelography or magnetic resonance imaging and play a decisive role in optimal patient-oriented therapy decision-making. (orig.)

  10. syndrome du canal carpien

    OpenAIRE

    boukraa, kheira; merniz, nacera

    2012-01-01

    Le canal carpien est la principale cause des acroparesthésies de la main. I La forme habituelle est la forme sensitive pure primitive de la femme en période I post ménopausique. Le traitement médical suffit le plus souvent. La constatation et l'installation de signes déficitaires neurologiques sont une indication à un traitement chirurgical. Le syndrome du canal carpien peut être un mode de début d'une polyarthrite u rhumatoïde.

  11. Bioenvironmental and radiological-safety feasibility studies, Atlantic-Pacific Interoceanic Canal. Phase 2, Freshwater ecology: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Templeton, W.L.; Dean, J.M.; Watson, D.G.; Rancitelli, L.A. [Pacific Northwest Lab., Richland, WA (United States); Loftin, H.G. [Consultant, Florida State Univ. (United States)

    1968-06-28

    The purpose of this program is to conduct studies in the freshwater environment to acquire data needed to evaluate and predict the potential radiation hazards to human populations in the defined regions of proposed nuclear excavations in the Republics of Panama and Colombia. The results of the field surveys conducted in Phase II are presented in this report. Specifically, the data describes the elemental composition of the major components of the ecosystem, and reports the calculated stable element concentration factors for the major food organisms. This data provides baseline values from which predictions can be made of the potential maximum radionuclide intake by populations using this resource.

  12. A study on the nuclear technology policy

    International Nuclear Information System (INIS)

    This study was conducted as a part of institutional activities of KAERI, and the objective of the study is to survey and analyze the change of international environment in nuclear use and research and development environment, and to propose systematic alternatives on technology policy for efficiency and effectiveness of research and development through national R and D program while timely responding to the environmental change in local and global sense. Acknowledging the importance of the relationship between the external environment and the national nuclear R and D strategic planning for changing of environment of surrounding nuclear technology and development in the world, this study focused on the three major subjects: (1) investigation and analysis of international nuclear environmental and technological change; (2) developing nuclear R and D strategy based on the analysis of national and global environment surrounding nuclear technology development and diffusion; (3) the evaluation of role of nuclear technology and environment from the point of views of environmental effects. In order to enhance the role of national nuclear R and D program and to cope with the environmental and technological change surrounding nuclear energy, it is recommended that active participation should be done in ongoing international collaboration on future innovative nuclear technology for absorption of advanced technologies and strategic R and D planning should be centered on core technology field based on long-term vision and suggested NuTRM considering future energy-environmental surroundings for maximized use of domestic technology capabilities and resources

  13. The evolutionary genetics of canalization.

    Science.gov (United States)

    Flatt, Thomas

    2005-09-01

    Evolutionary genetics has recently made enormous progress in understanding how genetic variation maps into phenotypic variation. However why some traits are phenotypically invariant despite apparent genetic and environmental changes has remained a major puzzle. In the 1940s, Conrad Hal Waddington coined the concept and term "canalization" to describe the robustness of phenotypes to perturbation; a similar concept was proposed by Waddington's contemporary Ivan Ivanovich Schmalhausen. This paper reviews what has been learned about canalization since Waddington. Canalization implies that a genotype's phenotype remains relatively invariant when individuals of a particular genotype are exposed to different environments (environmental canalization) or when individuals of the same single- or multilocus genotype differ in their genetic background (genetic canalization). Consequently, genetic canalization can be viewed as a particular kind of epistasis, and environmental canalization and phenotypic plasticity are two aspects of the same phenomenon. Canalization results in the accumulation of phenotypically cryptic genetic variation, which can be released after a "decanalizing" event. Thus, canalized genotypes maintain a cryptic potential for expressing particular phenotypes, which are only uncovered under particular decanalizing environmental or genetic conditions. Selection may then act on this newly released genetic variation. The accumulation of cryptic genetic variation by canalization may therefore increase evolvability at the population level by leading to phenotypic diversification under decanalizing conditions. On the other hand, under canalizing conditions, a major part of the segregating genetic variation may remain phenotypically cryptic; canalization may therefore, at least temporarily, constrain phenotypic evolution. Mechanistically, canalization can be understood in terms of transmission patterns, such as epistasis, pleiotropy, and genotype by environment

  14. Histopathological Study of Periapical Inflammation Following Preparation of the Root Canal with Conventional and Profile Rotary Instrumentation in Teeth of Cats

    Directory of Open Access Journals (Sweden)

    M. Bidar

    2005-03-01

    Full Text Available Statement of Problem: Various factors are involved in causing inflammation following root canal treatment. Controlling these factors may relieve the related pain. One of these factors is extrusion of debris beyond the apex. Although debris extrusion happens in all instrumentation techniques, researchers have declared that in coronal flaring technique,there is minimum debris extrusion.Purpose: The purpose of this study was to evaluate and compare the inflammation of periapical area following root canal therapy, using conventional and profile rotary instrumentation in cats' teeth, from a histopathological point of view.Materials and Methods: This experimental study conducted on thirty Persian one year old cats. Three groups of samples were chosen and treated with different methods. First group were prepared by step-back instrumentation technique using stainless steel Ktypefiles. Second group were prepared by crown down technique using Ni-Ti files.Third group were prepared using profile GT rotary system at 150-rpm speed. Animals were subjected to vital perfusion at 8, 24 & 48 hour intervals after instrumentation. The canine teeth were separated from the jaw along with some of the supporting structures.Then decalcification and laboratory processing were carried out and samples were evaluated histologically. Collected data were analyzed using Kruskal-Wallis test.Results: The results showed that in vital teeth with no evidence of periapical pathosis,the inflammation following various instrumentation methods was not statistically different.Conclusion: In vital teeth, the periapical inflammation following various methods of instrumentation is not statistically different.

  15. Endodontic management of mandibular first molar with seven canals using cone-beam computed tomography

    Science.gov (United States)

    Banode, Ankur Mahesh; Gade, Vandana; Patil, Sanjay; Gade, Jaykumar

    2016-01-01

    The endodontic treatment of a mandibular molar with aberrant canal configuration can be diagnostically and clinically challenging. Successful endodontic therapy thus depends on the clinician's ability to anticipate and look for these aberrant variations. A mandibular first molar with seven canals represents a rare anatomical variant, particularly when four canals are found in distal root. Based on in vitro studies, its incidence is reported to be between 0.2% and 3%. With the advent of cone-beam computed tomography (CBCT) as an adjunctive diagnostic aid, the determination of root canal anatomy in teeth with complex canal configurations has become more precise. The present case report discusses successful nonsurgical management of radix entomolaris along with middle mesial canal and middle distal canal in mandibular first molar with seven canals (four canals in distal and three in mesial) employing CBCT as an adjunctive diagnostic aid to conventional radiography. PMID:27307680

  16. Clinical study on the second mesiobuccal canal in the mesiobuccal root of the maxillary second primary molar%上颌第二乳磨牙近中颊根第二根管的临床研究

    Institute of Scientific and Technical Information of China (English)

    余锦锦; 方进华

    2013-01-01

    Objective To study the clinical incidence of the second mesiobuccal (MB2) root canal of maxillary second primary molars.Methods Detecting the fissure or grooves between the mesiobuccal and palatal canal orifices to investigate the Clinical incidence of the second mesiobuccal root canal of maxillary second primary molars.Results 26 molars of the 56 maxillary second primary molars in 54 patients had second mesiobuccal root canals.The incidence rate was 46.43%.There was no significant relationship between the incidence of an MB2 canal and gender and tooth position.Conclusion There was a high incidence of the second mesiobuccal root canal of maxillary second primary molars.To improve the success of endodontic treatment in maxillary second primary molars,more attention should be paid to locate the MB2 canals.%目的:研究上颌第二乳磨牙近中颊根第二根管(Second mesiobuccal root cana1,MB2)的临床发现率.方法:探查近中颊根根管口与腭根根管口之间的发育沟或暗线,研究上颌第二乳磨牙MB2的临床发现率.结果:54例患者共56颗上颌第二乳磨牙,其中有26颗存在MB2,发现率为46.43%.临床发现率在性别及牙位中无显著性差异.结论:上颌第二乳磨牙中MB2有较高的发现率,临床上应注意探查以免遗漏.

  17. A study on nuclear technology policy

    Energy Technology Data Exchange (ETDEWEB)

    Yang, M. H.; Kim, H. J.; Chung, W. S.; Yun, S. W.; Kim, H. S

    2001-01-01

    This study was carried out as a part of institutional activities of KAERI. Major research area are as follows; Future directions and effects for national nuclear R and D to be resulted from restructuring of electricity industry are studied. Comparative study was carried out between nuclear energy and other energy sources from the point of views of environmental effects by introducing life cycle assessment(LCA) method. Japanese trends of reestablishment of nuclear policy such as restructuring of nuclear administration system and long-term plan of development and use of nuclear energy are also investigated, and Russian nuclear development program and Germany trends for phase-out of nuclear electricity generation are also investigated. And trends of the demand and supply of energy in eastern asian countries in from the point of view of energy security and tension in the south china sea are analyzed and investigation of policy trends of Vietnam and Egypt for the development and use of nuclear energy for the promotion of nuclear cooperation with these countries are also carried out. Due to the lack of energy resources and high dependence of imported energy, higher priority should be placed on the use of localized energy supply technology such as nuclear power. In this connection, technological development should be strengthened positively in order to improve economy and safety of nuclear energy and proliferation resistance of nuclear fuel cycle and wide ranged use of radiation and radioisotopes and should be reflected in re-establishment of national comprehensive promotion plan of nuclear energy in progress.

  18. A study on nuclear technology policy

    International Nuclear Information System (INIS)

    This study was carried out as a part of institutional activities of KAERI. Major research area are as follows; Future directions and effects for national nuclear R and D to be resulted from restructuring of electricity industry are studied. Comparative study was carried out between nuclear energy and other energy sources from the point of views of environmental effects by introducing life cycle assessment(LCA) method. Japanese trends of reestablishment of nuclear policy such as restructuring of nuclear administration system and long-term plan of development and use of nuclear energy are also investigated, and Russian nuclear development program and Germany trends for phase-out of nuclear electricity generation are also investigated. And trends of the demand and supply of energy in eastern asian countries in from the point of view of energy security and tension in the south china sea are analyzed and investigation of policy trends of Vietnam and Egypt for the development and use of nuclear energy for the promotion of nuclear cooperation with these countries are also carried out. Due to the lack of energy resources and high dependence of imported energy, higher priority should be placed on the use of localized energy supply technology such as nuclear power. In this connection, technological development should be strengthened positively in order to improve economy and safety of nuclear energy and proliferation resistance of nuclear fuel cycle and wide ranged use of radiation and radioisotopes and should be reflected in re-establishment of national comprehensive promotion plan of nuclear energy in progress

  19. Mapping ear canal movement using area-based surface matching

    Science.gov (United States)

    Grenness, Malcolm J.; Osborn, Jon; Weller, W. Lee

    2002-02-01

    Movement of the external ear canal, associated with jaw motion, relative to the concha region of the pinna has been studied. Pairs of open-jaw and closed-jaw impressions were taken of 14 ears from 10 subjects. Three-dimensional coordinate data were obtained from the concha and the anterior surface of the canal using a reflex microscope. Proprietary area-based matching software was used to evaluate distortion of the two surfaces between the two jaw positions. The canal data from each pair were placed into the same coordinate system with their respective concha regions aligned. Difference maps of the canal data were used to demonstrate the amount of anterior-posterior (A-P), superior-inferior (S-I), and medial-lateral (M-L) movement, relative to the concha, that occurred between the open- and closed-jaw impressions. The concha regions did not undergo significant deformation. The canal regions underwent varying amounts of deformation with all canals conforming within an rms of 136 μm across the entire surface. The majority of canals underwent significant movement relative to the concha. M-L movement ranged from +2.0 to -3.8 mm; eight canals moved laterally, five moved medially, and two showed no movement. S-I movement ranged from +3.7 to -2.7 mm; nine canals moved inferiorly, two moved superiorly, and three showed no movement. A-P movement ranged between +7.5 and -8.5 mm, with five canals moving anteriorly, three posteriorly, and four in a mixed fashion. This study has shown the variability of canal movement relative to the concha and does not support previous reports that suggest that the ear canal only widens with jaw opening.

  20. Nuclear biological studies in France

    International Nuclear Information System (INIS)

    On the occasion of a colloquium on radiobiological research programmes, a number of documents dealing with French accomplishments and projects in this field were collected together. We felt that it would be useful to assemble these papers in one report; although they are brief and leave gaps to be filled in, they provide certain data, give an overall view of the situation, and can also suggest a rough plan for the general policy to adopt in the field of 'nuclear' biological research; i.e. research based on the nuclear tracer method or devoted to the action of ionising radiations. (author)

  1. The role of resin cement on bond strength of glass-fiber posts luted into root canals: a systematic review and meta-analysis of in vitro studies.

    Science.gov (United States)

    Sarkis-Onofre, R; Skupien, J A; Cenci, M S; Moraes, R R; Pereira-Cenci, T

    2014-01-01

    Because there are several ways to cement glass-fiber posts (GFPs) into root canals, there is no consensus on the best strategy to achieve high bond strengths. A systematic review was conducted to determine if there is difference in bond strength to dentin between regular and self-adhesive resin cements and to verify the influence of several variables on the retention of GFPs. This report followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. In vitro studies that investigated the bond strength of GFPs luted with self-adhesive and regular resin cements were selected. Searches were carried out in the PubMed and Scopus databases. No publication year or language limit was used, and the last search was done in October 2012. A global comparison was performed between self-adhesive and regular resin cements. Two subgroup analyses were performed: 1) Self-adhesive × Regular resin cement + Etch-and-rinse adhesive and 2) Self-adhesive × Regular resin cement + Self-etch adhesive. The analyses were carried out using fixed-effect and random-effects models. The results showed heterogeneity in all comparisons, and higher bond strength to dentin was identified for self-adhesive cements. Although the articles included in this meta-analysis showed high heterogeneity and high risk of bias, the in vitro literature seems to suggest that use of self-adhesive resin cement could improve the retention of GFPs into root canals. PMID:23937401

  2. Effect of different final irrigating solutions on smear layer removal in apical third of root canal: A scanning electron microscope study

    Directory of Open Access Journals (Sweden)

    Sayesh Vemuri

    2016-01-01

    Full Text Available Aim: The aim of this in vitro study is to compare the smear layer removal efficacy of different irrigating solutions at the apical third of the root canal. Materials and Methods: Forty human single-rooted mandibular premolar teeth were taken and decoronated to standardize the canal length to 14 mm. They were prepared by ProTaper rotary system to an apical preparation of file size F3. Prepared teeth were randomly divided into four groups (n = 10; saline (Group 1; negative control, ethylenediaminetetraacetic acid (Group 2, BioPure MTAD (Group 3, and QMix 2 in 1 (Group 4. After final irrigation with tested irrigants, the teeth were split into two halves longitudinally and observed under a scanning electron microscope (SEM for the removal of smear layer. The SEM images were then analyzed for the amount of smear layer present using a three score system. Statistical Analysis: Data are analyzed using the Kruskal-Wallis test and Mann-Whitney U-test. Results: Intergroup comparison of groups showed statistically significant difference in the smear layer removal efficacy of irrigants tested. QMix 2 in 1 is most effective in removal of smear layer when compared to other tested irrigants. Conclusion: QMix 2 in 1 is the most effective final irrigating solution for smear layer removal.

  3. Clinical Comparative Study of Disposable and Reusable France Root Canal Treatment Pulpitis%牙髓炎治疗中应用一次性及多次法根管治疗临床对比研究

    Institute of Scientific and Technical Information of China (English)

    周颖蕊

    2014-01-01

    目的探究牙髓炎治疗中应用一次性及多次法根管治疗的临床对比研究。方法选100例患有牙髓炎患者为研究对象,随机分为观察组与对照组,分别行一次法根管、分次法根管治疗。结果实验组有效率、患者疼痛、满意度比较,实验组优于对照组,<0.05。结论发现一次法根管治疗效果优于分次法根管。%Objective To explore the application of disposable and reusable pulpitis comparative study of root canal therapy clinical treatment.Methods 100 cases of patients suf ering from pulpitis for the study were randomly divided into observation group and control group, respectively, a root canal line, graded root canal treatment.Results The experimental group was patients with pain, satisfaction, the experimental group than the control group, <0.05.Conclusion Find a method of root canal therapy is superior to graded root canal.

  4. A strategy study on international nuclear cooperation

    International Nuclear Information System (INIS)

    The implementing methodologies suggested from this study cover the following: 1) strategies for the promotion of the nation's leading roles in such international organizations as the IAEA and OECD/NEA; 2) strategies for the implementation of national nuclear policy, positively coping with international nuclear trends; 3) strategies for the promotion of technical cooperation with the Russian Federation to introduce essential nuclear technology by utilizing its new environment of science and technology. 39 tabs., 28 figs., 64 refs. (Author)

  5. Root canal medicaments.

    Science.gov (United States)

    Kawashima, Nobuyuki; Wadachi, Reiko; Suda, Hideaki; Yeng, Thai; Parashos, Peter

    2009-02-01

    The ultimate goals of endodontic treatment are complete removal of bacteria, their byproducts and pulpal remnants from infected root canals and the complete seal of disinfected root canals. Intracanal medicaments have been thought an essential step in killing the bacteria in root canals; however, in modern endodontics, shaping and cleaning may be assuming greater importance than intracanal medicaments as a means of disinfecting root canals. Until recently, formocresol and its relatives were frequently used as intracanal medicaments, but it was pointed out that such bactericidal chemicals dressed in the canal distributed to the whole body from the root apex and so might induce various harmful effects including allergies. Furthermore, as these medicaments are potent carcinogenic agents, there is no indication for these chemicals in modern endodontic treatment. Today, biocompatibility and stability are essential properties for intracanal medicaments. The more modern meaning of intracanal dressing is for a blockade against coronal leakage from the gap between filling materials and cavity wall. Calcium hydroxide has been determined as suitable for use as an intracanal medicament as it is stable for long periods, harmless to the body, and bactericidal in a limited area. It also induces hard tissue formation and is effective for stopping inflammatory exudates. Single-visit endodontics, where intracanal medicaments are not used, is generally not now contraindicated and various reports have shown that the clinical outcomes between single- and multiple- visit endodontics are similar. There is no reason to counsel against single-visit endodontics: however, if multiple-visit endodontics is chosen, calcium hydroxide is recommended to be used as an intracanal medicament. PMID:19323305

  6. Preliminary nuclear terrorist effects study

    International Nuclear Information System (INIS)

    The nuclear device is assumed to be a small-yield (less than a few tens of kilotons) fission device. A location of such a device in a city street is assumed, and the probable behavior of the blast wave, thermal radiation, and fallout is discussed

  7. 不同根管消毒药物对根管治疗效果影响的临床研究%Clinical study on the effect of different root canal disinfection drugs on root canal therapy

    Institute of Scientific and Technical Information of China (English)

    马丽娅

    2016-01-01

    目的:探讨不同根管消毒药物对根管治疗效果的影响.方法:收治急慢性根尖周炎患者180例(患牙180颗),将其划分为甲醛甲酚组、奥硝唑组以及氢氧化钙组,并分别利用这3种消毒药物对患者实施根管治疗,观察3组治疗效果.结果:经治疗后,奥硝唑组以及氢氧化钙组的临床效果明显优于甲醛甲酚组(P<0.05),差异有统计学意义.结论:对急慢性根尖周炎患者在根管治疗中应用奥硝唑以及氢氧化钙消毒药物的治疗效果显著.%Objective:To discuss the treatment effect of different root canal disinfection drugs on root canal therapy.Method:There were 180 teeth of 180 patients with acute or chronic periapical periodontitis divided into the formaldehyde cresol formocresol group,the ornidazole group and the calcium hydroxide group.The three kinds of disinfection drugs were used to treat patients with root canal therapy, and the treatment effect of the three groups were observed.Results:After treatment,the clinical effect of ornidazole group and calcium hydroxide group was obviously better than that of formaldehyde cresol formocresol group(P<0.05). There was a significant difference.Conclusion:The treatment effect of root canal therapy by ornidazole and calcium hydroxide for patients with acute or chronic periapical periodontitis was significant.

  8. Assessment of the wetting behavior of three different root canal sealers on root canal dentin

    OpenAIRE

    Muralidhar Tummala; Veeramachaneni Chandrasekhar; A Shashi Rashmi; Kundabala, M; Vasudev Ballal

    2012-01-01

    Aim: The objective of the present study was to evaluate and compare the wetting behavior of three different root canal sealers on the root canal dentin surface treated with irrigants and their combination. Materials and Methods: Decoronation and apical third resections of 27 extracted single-rooted human mandibular premolars were done. The roots were then split longitudinally into two halves, and randomly assigned into three treatment groups (n=18). The root dentin surfaces in Group1, Gro...

  9. Morphometric analysis of the cervical spinal canal on MRI.

    Science.gov (United States)

    Matveeva, Niki; Janevski, Petar; Nakeva, Natasha; Zhivadinovik, Julija; Dodevski, Ace

    2013-01-01

    Two useful numerical values, called the Torg ratio and the spinal canal diameter (SC diameter) are widely accepted as reliable morphometric determinants of spinal stenosis. The aims of the study were to examine morphometric determinants of the cervical spinal canal on MRI in both sexes and analyse them as reliable indicators of spinal stenosis. Measurements were made on 50 MR images (sagittal T2 weighted images from C3 to C7) of the cervical spine of patients from the Emergency Centre who had undertaken MRI of the cervical spine in addition to CT for various diagnostic indications. Torg ratio, used in evaluation of the spinal canal stenosis on plain x-ray radiographs, cannot be used as a spinal canal stenosis indicator due to the gender differences in the vertebral bodies' width. Sagittal canal diameters were more spread out in males than in females. MRI enables the value of the space available for the spinal cord, (SAC) to be determined, by subtracting the sagittal diameter of the spinal cord from the sagittal diameter of the spinal canal. Not gender, but individual and level differences in the SAC values were evident (cervical cord enlargement). SAC values relied more on the spinal canal than on the spinal cord, so that the differences in the dimensions of the spinal cord accounted for less variability in the SAC values. MR imaging of the cervical spine provides more accurate cervical canal and spinal cord measurements that could serve as morphometric determinants of the cervical canal stenosis. PMID:24280784

  10. Nuclear decay studies and weak interactions

    CERN Document Server

    Dessagne, P

    2002-01-01

    The study of beta decay contributes to our knowledge on both the fundamental aspects of the weak interaction and the nuclear structure. Moreover, this process plays an essential role in the definition of the astrophysical scenarios. The extensive work performed on Fermi transitions, double beta decay and first forbidden transitions allows to test predictions of the Standard Model. For nuclear structure, a specific feature of beta decay is the possibility to compare theoretical evaluations with experimental information over a wide range of masses. Nuclear gross properties and detailed nuclear structure information can be obtained in many cases far from stability.

  11. Nuclear decay studies and weak interactions

    International Nuclear Information System (INIS)

    The study of beta decay contributes to our knowledge on both the fundamental aspects of the weak interaction and the nuclear structure. Moreover, this process plays an essential role in the definition of the astrophysical scenarios. The extensive work performed on Fermi transitions, double beta decay and first forbidden transitions allows to test predictions of the Standard Model. For nuclear structure, a specific feature of beta decay is the possibility to compare theoretical evaluations with experimental information over a wide range of masses. Nuclear gross properties and detailed nuclear structure information can be obtained in many cases far from stability

  12. Electromagnetic studies of nuclear structure and reactions

    International Nuclear Information System (INIS)

    This report contains papers on the following topics: giant resonance studies; deep inelastic scattering studies; high resolution nuclear structure work; and relativistic RPA; and field theory in the Schroedinger Representation

  13. Curved canals: Ancestral files revisited

    Directory of Open Access Journals (Sweden)

    Jain Nidhi

    2008-01-01

    Full Text Available The aim of this article is to provide an insight into different techniques of cleaning and shaping of curved root canals with hand instruments. Although a plethora of root canal instruments like ProFile, ProTaper, LightSpeed ® etc dominate the current scenario, the inexpensive conventional root canal hand files such as K-files and flexible files can be used to get optimum results when handled meticulously. Special emphasis has been put on the modifications in biomechanical canal preparation in a variety of curved canal cases. This article compiles a series of clinical cases of root canals with curvatures in the middle and apical third and with S-shaped curvatures that were successfully completed by employing only conventional root canal hand instruments.

  14. Nuclear magnetic resonance studies of erythrocyte membranes

    NARCIS (Netherlands)

    Chapman, D.; Kamat, V.B.; Gier, J. de; Penkett, S.A.

    1968-01-01

    The use of nuclear magnetic resonance spectroscopy for studying molecular interactions in biological membranes has been investigated using erythrocyte membrane fragments. Sonic dispersion of these fragments produces a sharp and well-defined high-resolution nuclear magnetic resonance spectrum. The sp

  15. Studies on the pathogenesis of the degenerative lumbar canal stenosis by CT, 3. Clinical studies on the pathogenesis of the degenerative LCS

    Energy Technology Data Exchange (ETDEWEB)

    Kido, Kenji

    1988-03-01

    Computed tomography (CT) scans of lumbar canal stenosis (LCS, n = 20), osteoarthritis (OA, n = 65), disk herniation (n = 21), and lumbar pain (n = 23) were reviewed for the quanlitative evaluation of the vertebral canal and stenosis factors. Trefoil type on transverse sections of the bony vertebral canal was observed in 23 %, having no implications for pathologic significance at the L5 level. The degree of degeneration in soft tissues inside the vertebral canal varied according to diseases. This was most noticeable at the L4/L5 level in the LCS group. The morphological CT appearance of vertebral arch were divided into three types: I - the concave inner part, II - the linear inner part, and III - the convex inner part to the vertebral canal. In the group of LCS, the incidences of types II and III were high at the L5/S1 and at the L4/L5 levels, respectively. As for the angle of apophyseal joint, the incidence of sagittal joint was high at the L3/L4 and L4/L5 levels in the group of LCS. The incidence of degenerative changes was high in the groups of LCS and OA, suggesting some relationship between degenerative degree and both sagittal and asymmetric joints. This was noticeable at the L4/L5 level. Calcification surrounding the joint was seen in 13 %, reflecting the relationship to the degenerative changes. There was no relationship between degenerative changes and vacuum joint phenomenon observed in 18 %. As for the area less than 90 mm/sup 2/ of the dural canal, there was no morphological change between the LCS and OA groups. In the symptomatic mechanism in the case of LCS, morphological dynamic and unstable factors may be involved. (Namekawa, K.) 67 refs.

  16. Study of root canal filling in dogs by using compound coral paste%珊瑚糊剂用于狗牙根管充填的实验

    Institute of Scientific and Technical Information of China (English)

    雷志敏; 张敏

    2008-01-01

    BACKGROUND: The root canal filling materials available have different degrees of noxious stimulation to periapical tissue and cannot induce growth and regeneration of bone at the periapical region. Moreover, the operation of canal filling is not easily controlled.OBJECTIVE: To investigate biocompatibility and osteoconductivity between periapical tissue and compound coral paste after root canal filling.DESIGN: Controlled observation.SETTING: Department of Stomatology in the Renmin Hospital of Wuhan University.MATERIALS: The experiment was carried out in the Key Laboratory for Oral Biomedical Engineering by the State Ministry of Education, School of Stomatology in Wuhan University from September 2002 to January 2006. Eight adult female mongrel dogs, weighed 15 kg, were offered by the Wuhan General Hospital of Guangzhou Military Area Command of Chinese PLA (SYXK-2003-0007). Each dog contained 32 root canals, and totally 256 root canals were utilized in this study.METHODS: Experimental animals underwent general anesthesia by the intravenous injection of sodium pentobarbital (30 mg/kg), then tracheal intubation was utilized for the root canal filling, and the canals were randomly distributed into two groups: experimental group (n=128) with compound coral paste (coral 40 g and iodoform 8 g, offered by the Key Laboratory for Oral Biomedical Engineering by the State Ministry of Education, School of Stomatology in Wuhan University); control group (n=128) with gutta-percha point+zinc oxide-eugenol sealer. One animal was sacrificed by anesthetic overdose at 2, 4, 12 and 24 weeks after root canal filling, dental film by X-ray and light microscope were used for the examination.MAIN OUTCOME MEASURES: ①Periapical inflammation: Cells were counted in a high power field, and three levels were defined as mild (<100 cells/mm2), moderate (100-200 cells/mm2) and severe (>200 cells/mm2).②destruction and regeneration of periapical tissues.③bone substitute of compound coral paste

  17. Long-term nuclear development study

    International Nuclear Information System (INIS)

    The future supply/demand structure of total and electrical energy has been analyzed, and the sectoral energy demand forecasts for industrial, residential, transportational, and other sectors have been attempted in this study. According to the firmly established nuclear power program, 6 nuclear units by 1986 and 13 nuclear units by 1991 will be in operation in Korea. However, no official nuclear power program has been established yet beyond 1991. Therefore, the extended nuclear power planning in the years to come after 1991 has been analyzed strategically based on the supply/demand views of total energy, nuclear fuel cycle and technical manpower requirements. In addition, the optimum reactor mix scenarios among PWR, HWR and FBR have been formulated and evaluated by looking at the longterm views of both required nuclear technology developments contributing to directly domestic commercialization and the core nuclear technologies to be developed intensively with high priority. From the supply/demand view points of nuclear fuel cycle requirements, the FBR operation before the year 2000 in Korea has been resulted in economical justification. Furthermore, assuming that the FBR operation would be delayed until the year 2010, the thermal recycle possibilities of the separated plutonium or uranium from thermal reactors also have been analyzed in a sense of spent fuel storage and waste disposal. (Author)

  18. A study on the nuclear technology policy

    International Nuclear Information System (INIS)

    This study analyzed the major issues as the research activities for the support of establishment and implementation of national policy. The analyses were focused on the recommendations of the responsive direction of national policy in positive and effective manners in accordance with the changes of international nuclear affairs. This study also analyzed the creation of environmental foundation for effective implementation of the national policy and national R and D investment such as securing national consensus and openings of policy information to the public. The major results of the role and position of nuclear policy, trends of nuclear policy and nuclear R and D activities of USA, France, Japan, Asian developing countries etc. and international trends of small- and medium-sized reactor as well as spin-offs of nuclear R and D activities, were analyzed. (author). 66 refs., 27 tabs., 15 figs

  19. A study on the nuclear technology policy

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Maeng Ho; Ham, C. H.; Kim, H. J.; Chung, W. S.; Lee, T. J.; Lee, B. O.; Yun, S. W.; Choi, Y. M.; Eom, T. Y

    1998-01-01

    This study analyzed the major issues as the research activities for the support of establishment and implementation of national policy. The analyses were focused on the recommendations of the responsive direction of national policy in positive and effective manners in accordance with the changes of international nuclear affairs. This study also analyzed the creation of environmental foundation for effective implementation of the national policy and national R and D investment such as securing national consensus and openings of policy information to the public. The major results of the role and position of nuclear policy, trends of nuclear policy and nuclear R and D activities of USA, France, Japan, Asian developing countries etc. and international trends of small- and medium-sized reactor as well as spin-offs of nuclear R and D activities, were analyzed. (author). 66 refs., 27 tabs., 15 figs

  20. Comparison of two sonic handpieces during the preparation of simulated root canals.

    Science.gov (United States)

    Dummer, P M; Hutchings, R; Hartles, F R

    1993-05-01

    The objective of this study was to assess and compare two sonic handpieces during the preparation of simulated root canals. A total of 60 simulated canals in clear resin blocks of various angles and positions of curvature were prepared using Shaper files activated either by an MM1500 Sonic Air or an MM1400 Mecasonic handpiece. Each handpiece was used to prepare 30 canals using an identical preparation procedure which involved a linear filing motion and an anticurvature technique in curved canals. The efficacy of the handpieces was determined for straight and curved canals separately and included an assessment of loss of canal length, weight loss from the blocks, smoothness of canal walls, transportation and overall shape of the prepared canals. Canals were prepared rapidly and effectively by both handpieces. Overall, the MM1500 handpiece was associated with significantly less distance loss (P canals (8%) had hour-glass shapes displaying zips and elbows, each handpiece created two. Only two canals (4%) had danger zones, both were created by the MM1400 handpiece. There was little difference between the handpieces in terms of the smoothness of canal walls, the direction and amount of transportation or the overall shape of canals. Under the conditions of this study, the new MM1400 Mecasonic handpiece performed as well as the established MM1500 Sonic Air. PMID:8406963

  1. Root canal filling evaluation using optical coherence tomography

    Science.gov (United States)

    Negrutiu, Meda L.; Sinescu, Cosmin; Topala, Florin; Nica, Luminita; Ionita, Ciprian; Marcauteanu, Corina; Goguta, Luciana; Bradu, Adrian; Dobre, George; Rominu, Mihai; Podoleanu, Adrian Gh.

    2010-04-01

    Endodontic therapy consists in cleaning and shaping the root canal system, removing organic debris and sealing the intra-canal space with permanent filling materials. The purpose of this study was to evaluate various root canal fillings in order to detect material defects, the marginal adaptation at the root canal walls and to assess the quality of the apical sealing. 21 extracted single-root canal human teeth were selected for this study. We instrumented all roots using NiTi rotary instruments. All canals were enlarged with a 6% taper size 30 GT instrument, 0,5 mm from the anatomical apex. The root canals were irrigated with 5% sodium hypochlorite, followed by 17% ethylenediaminetetraacetic acid (EDTA). After the instrumentation was completed, the root canals were obturated using a thermoplasticizable polymer of polyesters. In order to assess the defects inside the filling material and the marginal fit to the root canal walls, the conebeam micro-computed tomography (CBμCT) was used first. After the CBμCT investigation, time domain optical coherence tomography working in en face mode (TDefOCT) was employed to evaluate the previous samples. The TDefOCT system was working at 1300 nm and was doubled by a confocal channel at 970 nm. The results obtained by CBμCT revealed no visible defects inside the root-canal fillings and at the interfaces with the root-canal walls. TDefOCT investigations permit to visualize a more complex stratificated structure at the interface filling material/dental hard tissue and in the apical region.

  2. Environmental assessment of water and soil contamination in Rajakhali Canal of Karnaphuli River (Bangladesh) impacted by anthropogenic influences: a preliminary case study

    Science.gov (United States)

    Islam, M. Rafiqul; Das, N. G.; Barua, Prabal; Hossain, M. Belal; Venkatramanan, S.; Chung, S. Y.

    2015-07-01

    Soil and water quality determines the health of an aquatic ecosystem. Rajakhali Canal, a tributary of Karnaphuli River estuary, flowing through Chittagong City (the commercial capital of Bangladesh) receives a huge amount of domestic and industrial wastes and sewages. Monitoring the environmental status of Karnaphuli River and its tributaries is very important for their ecological and economical services provided to city areas. This study evaluated some environmental characteristics of water and soil in the Rajakhali Canal as it affected the environment, and ultimately the life and human beings of Chittagong City. The mean concentrations of physico-chemical parameters were pH (8.5), DO (0.1 mg/L), TA (47.6 mg/L), TDS (631.8 mg/L), TSS (280 mg/L), SO4-S (2.3 mg/L), NH3 (1.1 mg/L), NO3-N (0.2 mg/L) and PO4-P (0.1 mg/L) in the dry season. During the rainy season, the mean concentrations of physico-chemical parameters were pH (7.01), DO (0.55 mg/L), TA (65.9 mg/L), TDS (653.6 mg/L), TSS (300.3 mg/L), SO4-S (1 mg/L), NH3 - (0.6 mg/L), (NO3-N (0.3 mg/L) and PO4-P (0.5 mg/L) in water. In case of soil, the mean concentration of physico-chemical parameters in dry and rainy seasons was represented respectively as follows: pH (6.8), OM (4.5 %), sand (71.7 %), silt (3.1 %), clay (25.2 %), organic nitrogen (45.4 ppm) and phosphorus (9.6 ppm); and pH (6.7), OM (4.5 %), sand (74.4 %), silt (2.4 %), clay (23.2 %), organic nitrogen (35.3 ppm) and phosphorus (7.6 ppm). The result revealed that water and soil quality of this canal became deteriorated and that the total environment of the water body became polluted due to the anthropogenic activities such as industrial, domestic and irrigation effluents. Statistical analyses also supported that water and soil parameters were strongly correlated (1-tailed 0.05 level and 0.01 level significant) with each other at all stations during all seasons. The result of this study will be useful for management and planning for water quality

  3. Shaping ability of the M4 handpiece and Safety Hedstrom files in simulated root canals.

    Science.gov (United States)

    Lloyd, A; Jaunberzins, A; Dhopatkar, A; Bryant, S; Dummer, P M

    1997-01-01

    The aim of this study was to assess the shaping ability of the M4 reciprocating handpiece and Safety Hedstrom files in simulated canals. A total of 40 simulated canals of various angles and positions of curvature were prepared with an M4 handpiece using Safety Hedstrom files oriented with the ground, flattened surface towards the inner aspect of the curve. A standard regimen was adopted throughout. Pre- and post-operative longitudinal images of the canals were taken with a video camera and stored and manipulated in a computer with image analysis software. The presence of canal aberrations and the amount and location of resin material removed as a result of preparation were determined from composite images of superimposed pre- and post-operative views. Preparation time varied significantly (P canal types; overall, 20 degrees canals were prepared more quickly than 40 degrees canals. Zips and elbows were observed in 16 out of the 40 canals with most (11) being created in 40 degrees specimens. Ledges were found in 19 canals and perforations in only 1. There were no significant differences between canal shapes for these aberrations. Excessive removal of material from the inner aspect of the canal at the curve to create a danger zone was found in 20 canals, but only in those with 40 degrees curves. Significant differences in total canal width between the canal types were seen at the zips (P danger zones (P danger zones varied significantly (P canal types. Under the conditions of this study, the M4 handpiece and Safety Hedstrom files created hour-glass preparations in a substantial proportion of canals. In reality, the Safety Hedstrom file with its one flattened surface was ineffective at reducing removal of material along the inner aspect of canal curves in severely curved specimens and clearly has the potential to create strip perforations in teeth. PMID:9477790

  4. Nuclear power options viability study

    International Nuclear Information System (INIS)

    The Oak Ridge National Laboratory has chosen to assess the present nuclear energy situation and to evaluate new directions which may offer opportunity for improvement. Options for industry, regulation, and research are considered in these assessments. Smaller reactors (500 MW or less) were chosen for emphasis because they have received less recent attention than larger units and because they fit the current lower power demand projections. They also offer potential for increased shop fabrication and standardization. Even so, larger units also must be considered since improvements are planned and they offer economy of scale. A time scale has been chosen appropriate for placing of commercial orders between the years 2000 and 2010

  5. Nuclear spectroscopic studies. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Bingham, C.R.; Riedinger, L.L.; Sorensen, S.P.

    1996-01-16

    This report describes progress in the experimental nuclear physics program of the University of Tennessee, Knoxville. It presents findings related to properties of high-spin states, low-energy levels of nuclei far from stability, and high-energy heavy-ion physics, as well as a brief description of the Joint Institute of Heavy Ion Research (a collaboration between the University of Tennessee, Vanderbilt University, and Oak Ridge National Laboratory) and its activities (particularly those of the last few years), and a list of publications. 89 refs., 18 figs., 5 tabs.

  6. Nuclear spectroscopic studies. Progress report

    International Nuclear Information System (INIS)

    This report describes progress in the experimental nuclear physics program of the University of Tennessee, Knoxville. It presents findings related to properties of high-spin states, low-energy levels of nuclei far from stability, and high-energy heavy-ion physics, as well as a brief description of the Joint Institute of Heavy Ion Research (a collaboration between the University of Tennessee, Vanderbilt University, and Oak Ridge National Laboratory) and its activities (particularly those of the last few years), and a list of publications. 89 refs., 18 figs., 5 tabs

  7. Managing curved canals

    Directory of Open Access Journals (Sweden)

    Iram Ansari

    2012-01-01

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

  8. Water Environment Evolution along the China Grand Canal

    Science.gov (United States)

    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

  9. Water Environment Evolution along the China Grand Canal

    International Nuclear Information System (INIS)

    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

  10. A study on nuclear technology policy

    International Nuclear Information System (INIS)

    This study was conducted as a part of institutional activities of KAERI, and the objective of the study is to survey and analyze the change of international environment in nuclear use and research and development environment, and to propose systematic alternatives on technology policy for efficiency and effectiveness of research and development through national R and D program while timely responding to the environmental change in local and global sense. Acknowledging the importance of the relationship between the external environment and the national nuclear R and D strategic planning, this study focused on the two major subjects: (1) the international environmental and technological change attached to the development of nuclear power; (2) the direction and strategy of nuclear R and D to improve effectiveness through national R and D programs as role of electricity in the future society, strategic environment of nuclear use and R and D in the future society, energy environment and nuclear technology development scenario in the future, strategic study on future vision of KAERI and technological road-mapping of national nuclear R and D for enhancing competitiveness

  11. Nuclear power planning study for Saudi Arabia

    International Nuclear Information System (INIS)

    The prospects of application of nuclear energy for production of electricity and desalinated water in the Kingdom are evaluated. General economic development of the country and data on reserves, production and consumption of oil and natural gas are reviewed. Electrical power system is described with data on production and consumption. Estimates of future power demand are made using Aoki method. Costs of production of electricity from 600 MW, 900 MW and 1200 MW nuclear and oil-fired power plants are calculated along with the costs of production of desalinated water from dual purpose nuclear and oil-fired plants. The economic analysis indicates that the cost of production of electricity and desalinated water are in general cheaper from the nuclear power plants. Suggests consideration of the use of nuclear energy for production of both electricity and desalinated water from 1415 H. Further detailed studies and prepartory organizational steps in this direction are outlined. 38 Ref

  12. Study of the difference in rectal and ear canal temperature according to the conformation of the acoustic conch in dogs
    Estudo da diferença das temperaturas retal e do canal auditivo de acordo com a conformação da concha acústica em cães

    OpenAIRE

    Eduardo Negri Mueller; Lucimara Konflanz Bergmann; Andreia Nobre Anciuti; Mariana Teixeira Tillmann; Márcia de Oliveira Nobre

    2012-01-01

    The auditory thermometry has being used for measurement of temperature of dogs. However there is different acoustic conch conformation in this species, being that the pendulous ears can alter the auditory microclimate. This research aimed to study the difference of rectal and auditory canal temperatures according to acoustic conch conformation in dogs. One hundred and eleven dogs were used with erect ears (group I), semi-pendulous (group II) and pendulous (group II) with 37 animals each group...

  13. Study on nuclear power introduction into Vietnam

    International Nuclear Information System (INIS)

    The report presents main results of the study on nuclear power introduction into Vietnam which have been carried out at Vietnam Atomic Energy Commission in collaboration with Ministry of Industry of Vietnam and other countries like Japan, Canada and Korea. The study covers all topics related to the nuclear power introduction into Vietnam such as electricity demands and supply, economics, finance, technology, safety, manpower, site selection etc. (author)

  14. Theoretical studies in nuclear reactions and nuclear structure: Progress report

    International Nuclear Information System (INIS)

    This report discusses topics in nuclear theory. These general topics are: Quark physics, Quantum field theory, Relativistic nuclear physics, Nuclear dynamics, and Few-body problems and nonrelativistic methods

  15. Canal Wall Reconstruction Mastoidectomy

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Objective To investigate the advantages of canal wall reconstruction (CWR) mastoidectomy, a single-stage technique for cholesteatoma removal and posterior external canal wall reconstruction, over the open and closed procedures in terms of cholesteatoma recurrence. Methods: Between June 2002 and December 2005, 38 patients (40 ears) with cholesteatoma were admited to Sun Yat-Sen Memorial Hospital and received surgical treatments. Of these patients, 25 were male with ages ranging between 11 and 60 years (mean = 31.6 years) and 13 were female with ages ranging between 20 and 65 years (mean = 38.8 years). Canal wall reconstruction (CWR)mastoidectomy was performed in 31 ears and canal wall down (CWD) mastoidectomy in 9 ears. Concha cartilage was used for ear canal wall reconstruction in 22 of the 31 CWR procedures and cortical mastoid bone was used in the remaining 9 cases. Results At 0.5 to 4 years follow up, all but one patients remained free of signs of cholesteatoma recurrence, i.e., no retraction pocket or cholesteatoma matrix. One patient, a smoker, needed revision surgery due to cholesteatoma recurrence 1.5 year after the initial operation. The recurrence rate was therefore 3.2% (1/31). Cholesteatoma recurrence was monitored using postoperative CT scans whenever possible. In the case that needed a revision procedure, a retraction pocket was identified by otoendoscopy in the pars flacida area that eventually evolved into a cholesteatoma. A pocket extending to the epitympanum filled with cholesteatoma matrix was confirmed during the revision operation, A decision to perform a modified mastoidectomy was made as the patient refused to quit smoking. The mean air-bone gap in pure tone threshold was 45 dB before surgery and 25 dB after (p < 0.05). There was no difference between using concha cartilage and cortical mastoid bone for the reconstruction regarding air-bone gap improvement, CT findings and otoendoscopic results. Conclusion CWR mastoidectomy can be used for

  16. Carcinoma of the anal canal

    International Nuclear Information System (INIS)

    There are many unresolved issues in the management of epidermoid anal canal cancer, although substantial progress has been made in gaining acceptance of techniques that preserve anal function. Resolution of the most basic questions would require formal comparisons of radical surgery, radiation therapy alone, and combined modality therapy. However, patients are unlikely to participate in studies in which one or more options would offer a chance to avoid a colostomy. Informal comparisons of published series suggest that modern radiation therapy and combined modality therapy give survival rates similar to those reported following radical surgery. Other questions being addressed include identification of optimal radiation techniques, detailed exploration of the mechanisms, efficacy, and toxicity of drug and radiation combinations, and identification of effective systemic chemotherapy. All studies are made difficult by the relative rarity of this tumor. Even without formal clinical trials, however, the series reported the use of either radiation therapy alone or combined modality therapy as the initial treatment for epidermoid anal canal carcinoma, thereby preserving anal function whenever possible and reserving radical surgery for the patient with residual carcinoma

  17. Spatial orientation of semicircular canals and afferent sensitivity vectors in pigeons

    Science.gov (United States)

    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

  18. The Influence of Canalization on the Robustness of Boolean Networks

    CERN Document Server

    Kadelka, Claus; Laubenbacher, Reinhard

    2016-01-01

    Time- and state-discrete dynamical systems are frequently used to model molecular networks. This paper provides a collection of mathematical and computational tools for the study of robustness in Boolean network models. The focus is on networks governed by $k$-canalizing functions, a recently introduced class of Boolean functions that contains the well-studied class of nested canalizing functions. The activities and sensitivity of a function quantify the impact of input changes on the function output. This paper generalizes the latter concept to $c$-sensitivity and provides formulas for the activities and $c$-sensitivity of general $k$-canalizing functions as well as canalizing functions with more precisely defined structure. A popular measure for the robustness of a network, the Derrida value, can be expressed as a weighted sum of the $c$-sensitivities of the governing canalizing functions, and can also be calculated for a stochastic extension of Boolean networks. These findings provide a computationally eff...

  19. A central incisor with 4 independent root canals: a case report

    NARCIS (Netherlands)

    C. Aznar Portoles; A.T. Moinzadeh; H. Shemesh

    2015-01-01

    The maxillary central incisor is the tooth with the least anatomic variations. Despite the fact that several studies have reported a prevalence of 100% for the presence of a single canal, root canal aberrations of maxillary central incisors with up to 3 canals have also been reported. Such cases rep

  20. The ability of optical coherence tomography to characterize the root canal walls

    NARCIS (Netherlands)

    Shemesh, Hagay; Van Soest, Gijs; Wu, Min-Kai; Van der Sluis, Lucas W. M.; Wesselink, Paul R.

    2007-01-01

    A detailed understanding of the complexity of root canal systems is imperative to ensure successful root canal therapy. The aim of this study was to evaluate the ability of an optical coherence tomography (OCT) system in imaging root canal walls after endodontic preparation and to correlate these im

  1. Prevalence of Enterococcus faecalis and Porphyromonas gingivalis in infected root canals and their susceptibility to endodontic treatment procedures: A molecular study

    Directory of Open Access Journals (Sweden)

    Stojanović Nikola

    2014-01-01

    Full Text Available Introduction. Because apical periodontitis is recognizably an infectious disease, elimination or reduction of intracanal bacteria is of utmost importance for optimum treatment outcome. Objective. The prevalence of Enterococcus faecalis and Porphyromonas gingivalis in infected root canals was studied Also, the effect of endodontic therapy by using intracanal medicaments, calcium hydroxide paste (CH or gutta-percha points containing calcium hydroxide (CH-GP or chlorhexidine (CHX-GP on these microorganisms was assessed by polymerase chain reaction (PCR assay. Methods. Fifty-one patients with chronic apical periodontitis were randomly allocated in one of the following groups according to the intracanal medicament used: CH, CH-GP and CHX-GP group. Bacterial samples were taken upon access (S1, after chemomechanical instrumentation (S2 and after 15-day medication (S3. PCR assay was used to detect the presence of selected bacteria. Results. E. faecalis was detected in 49% (25/51 and P. gingivalis in 17.6% (9/51 of the samples. Samples which showed no bacterial presence at S1 were excluded from further analysis. Overall analysis of all 29 samples revealed significant differences between S1 and S2 (p<0.001, S2 and S3 (p<0.05, and S1 and S3 (p<0.001. When distinction was made between the intracanal medications, there was a significant difference in the number of PCR positive samples between S1 and S2, S1 and S3, but not between S2 and S3 samples. Conclusion. E. faecalis is more prevalent than P. gingivalis in primary endodontic infection. Intracanal medication in conduction with instrumentation and irrigation efficiently eliminates E. faecalis and P. gingivalis from infected root canals.

  2. 上颌第二磨牙根管变异情况观察%Clinical study of the root canal variations of maxillary second molars

    Institute of Scientific and Technical Information of China (English)

    余顺兰; 袁超; 司燕

    2015-01-01

    目的:观察临床治疗中上颌第二磨牙根管变异情况。方法:选择因牙髓炎、根尖周炎行根管治疗的147例150个上颌第二磨牙,对根管的变异情况进行观察、记录和分析。结果:150个上颌第二磨牙中,单根管牙2个,双根管牙18个,3根管牙115个其中1例颊腭各1根,颊侧根管为1-2型( V型根管);4根管牙15个,其中近中颊根第二根管13个(近中颊根1-2型1例),近、远中腭根根管2个。结论:上颌第二磨牙根管变异较大。%AIM: To observe the root canal variations of maxillary second molars from a clinical point of view. METHODS:150 maxillary second molars in 147 patients underwent root canal treatment were observed and the root canal morphology was observed and analyzed. RESULTS:Of the 150 maxillary second molars, 2 teeth had only 1 root canal;18 had 2 root canals;115 had 3 root canals;and 15 had 4 root canals. Second mesiobuccal(MB2) canal and second palatal canal were found in some of these cases. When the MB2 canal was present, one of the MB roots had a type V canal configuration. A type V canal configuration was also found in 1 of the teeth that had only 1 buccal root. CONCLUSION:The variation of maxillary second molars is comparatively large.

  3. Influence of coronal restorations on the fracture resistance of root canal-treated premolar and molar teeth: a retrospective study.

    Science.gov (United States)

    Dammaschke, Till; Nykiel, Kathrin; Sagheri, Darius; Schäfer, Edgar

    2013-08-01

    To evaluate the influence of coronal restorations on the fracture resistance of endodontically treated teeth, 676 root canal-filled and restored posterior teeth were evaluated after a mean period of 9.7 (± 2.8; minimum: 5) years. A total of 86.2% of the endodontically treated and restored teeth survived the mean observation period of 9.7 years without fracture. The overall survival period was 13.6 (± 0.2) years. All teeth with gold partial crowns survived without fractures (n = 24). Teeth with crowns and adhesively sealed access cavities showed a mean survival period of 15.3 (± 0.4) years, with crown and bridge restorations 14.0 (± 0.3), with individual metal posts 13.9 (± 0.2), with composite fillings 13.4 (± 0.5), with prefabricated metal posts 12.7 (± 0.6), with amalgam fillings 11.8 (± 0.6) and with glass ionomer cements (GIC) 6.6 (± 0.5) years. Teeth with one or two surfaces restored by amalgam, composite or GIC showed a significantly lower fracture rate than teeth with three and more restored surfaces (P < 0.05). The mean fracture rate of teeth restored with GIC was significantly higher when compared with all other groups (P < 0.001). In general, endodontically treated teeth restored with prosthetic restorations demonstrated a significantly lower mean fracture rate than teeth restored with fillings. Cavities with up to three surfaces may well be successfully restored adhesively with composite filling material. PMID:23890259

  4. Southeastern Utah Nuclear Waste Transportation Study

    OpenAIRE

    Bechtel Group Inc.

    1982-01-01

    This report is published as a product of the National Waste Terminal Storage (NWTS) Program. The objective of this program is the development of terminal waste storage facilities in deep stable geologic formations for high-level nuclear waste, including spent fuel elements from commercial power reactors and transuranic nuclear waste for which the Federal Government is responsible. The initial purpose of this study was to analyze and compare possible transport modes and corridors connectin...

  5. Nuclear Power Plant Lifetime Management Study (I)

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Sung Yull; Jeong, Ill Seok; Jang, Chang Heui; Song, Taek Ho; Song, Woo Young [Korea Electric Power Research Institute, Taejon (Korea, Republic of); Jin, Tae Eun [Korea Power Engineering Company Consulting and Architecture Engineers, (Korea, Republic of); Kim, Woo Chul [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1996-12-31

    As the operation-year of nuclear power plant increases and finding sites for new nuclear power plant becomes harder, a comprehensive and systematic nuclear plant lifetime management(PLIM) program including life extension has to be established for stable and safe supply of electricity. A feasibility study was conducted to systematically evaluate technical, economic and regulatory aspect of plant lifetime managements and plant life extension for Kori-1 nuclear power plant. For technical evaluation of nuclear power plant, 13 major components were selected for lifetime evaluation by screening system. structure, and components(SSCs) of the plant. It was found that except reactor pressure vessel, which needs detailed integrity analysis, and low pressure turbine, which is scheduled to be replaced, 11 out of 13 major components have sufficient service life, for more than 40 years. Because domestic rules and regulations related to license renewal has not yet been written, review on the regulatory aspect of life extensions was conducted using US NRC rules and regulations. A cooperative effort with nuclear regulatory body is needed for early completion of license renewal rules and regulations. For economic evaluation of plant lifetime extension, a computer program was developed and used. It was found that 10 to 20 year of extension operation of Kori-1 nuclear power plant was proved. Based on the results, next phase of plant lifetime management program for detailed lifetime evaluation and presenting detailed implementation schedule for plant refurbishment for lifetime extension should be followed. (author). 74 refs., figs.

  6. Apical pressures developed by needles for canal irrigation.

    Science.gov (United States)

    Bradford, C E; Eleazer, P D; Downs, K E; Scheetz, J P

    2002-04-01

    Drying instrumented canals with pressurized air may result in patient morbidity or even fatality. Low pressure and side vent needles have been suggested to lessen the danger. This study observed apical pressures from different needles inserted deeply into small round and ovoid canals as instrumentation progressed. Low-pressure (5 psi) air was injected through the needles, and apical pressures were recorded after each instrument. Pressures varied greatly within each test group. Generalities that can be drawn are that binding the needle within the canal gives higher pressures than with the needle slightly short of binding and that pressures were higher with apexes instrumented to size 30 and higher. With the needle tightly bound, neither needle size, needle design, nor canal shape resulted in statistically significant mean pressure differences. With the needle slightly withdrawn, larger bore needles gave higher pressures than small diameter needles. Caution is advised with the clinical use of pressurized air in the drying of root canals. PMID:12043877

  7. Direct solutions for normal depths in curved irrigation canals

    CERN Document Server

    Zhang, X Y

    2013-01-01

    The normal depth is an important hydraulic element for canal design, operation and management. Curved irrigation canals including parabola, U-shaped and catenary canals have excellent hydraulic performance and strong ability of anti-frost heave, while the normal depths in the governing equations of the current common methods have no explicit analytical solution. They are only indirect methods by using trial procedures, numerical methods, and graphical tools. This study presents new direct formulas for normal depth in curved irrigation canals by applying for Marquardt method. The maximum relative error of the proposed formulas is less than 1% within the practice range by comparative analysis, and they are simple and convenient for manual calculations. The results may provide the reliable theoretical basis and useful reference for the design and operation management of irrigation canals.

  8. Infrared tympanic temperature and ear canal morphology

    NARCIS (Netherlands)

    Daanen, H.A.M.

    2006-01-01

    Several publications indicate that the infrared tympanic temperature (IRTT) underestimates the core temperature of the body when the ear canal is long, curvy and narrow. In order to quantify these observations, a study was performed in 10 subjects. The IRTT was determined and compared to the oesopha

  9. CBCT应用于老年人磨牙根管治疗效果评价的临床研究%A study on clinical application of CBCT on molar root canal treatment for elderly patients

    Institute of Scientific and Technical Information of China (English)

    李泽键; 赖仁发

    2012-01-01

    目的:探讨CBCT在老年人磨牙根管治疗术后效果评价方面的作用及应用价值.方法:选取经临床确诊并决定进行根管治疗的老年人磨牙26例.所有病例均在根管治疗前行CBCT三维重建影像,由接诊医生仔细阅片了解患牙的根管系统形态,根管治疗结束后均行CBCT三维重建影像,从根管恰充率及根管充填密合程度两个方面评价根管治疗的质量及效果.所有患牙所采用的根管治疗方法、材料、器械均一致,且均由同一位医生完成治疗.结果:所有患牙均顺利完成根管治疗.根管恰充率高达86.49%,根管充填的密合程度评定为优良者达95.31%.结论:CBCT能够帮助临床医生于根管治疗术前充分了解老年人患牙根管系统的情况,在治疗过程中指导医生的治疗操作,且能够获得良好的根管充填质量.同时CBCT可以应用于老年人磨牙根管治疗术后效果的评价.CBCT在老年人磨牙根管治疗中具有显著的指导作用.%Objective: To explorer the effect and application value of CBCT for the elderly molar root canal therapy preoperative and postoperative through a clinical study. Methods: Twenty-six molars for the elderly patients were selected, which were clinically diagnosed and supposed to receive root canal therapy. Three-dimensional reconstruction of CBCT images were obtained before and after root canal therapy. All the selected teeth were received the same root canal therapy methods, materials, equipments, and completed by the same doctor. Results: All teeth had been finished root canal therapy. The rate of complete root canal filling was 86.49%, and the rate of first-rank root canal filling sealing degree was 95.31%. Conclusions: CBCT could help clinicians with a fall understanding of root canal system for the elderly patients before root canal therapy, offer guidelines for physicians to perform operations, and promote to accomplish good quality of root canal obturation. CBCT

  10. Weak interaction studies from nuclear beta decay

    International Nuclear Information System (INIS)

    The studies performed at the theoretical nuclear physics division of the Laboratory of Nuclear Studies, Osaka University, are reported. Electron spin density and internal conversion process, nuclear excitation by electron transition, beta decay, weak charged current, and beta-ray angular distributions in oriented nuclei have been studied. The relative intensity of internal conversion electrons for the case in which the radial wave functions of orbital electrons are different for electron spin up and down was calculated. The calculated value was in good agreement with the experimental one. The nuclear excitation following the transition of orbital electrons was studied. The calculated probability of the nuclear excitation of Os189 was 1.4 x 10-7 in conformity with the experimental value 1.7 x 10-7. The second class current and other problems on beta-decay have been extensively studied, and described elsewhere. Concerning weak charged current, the effects of all induced terms, the time component of main axial vector, all partial waves of leptons, Coulomb correction for the electrons in finite size nuclei, and radiative correction were studied. The beta-ray angular distribution for the 1+ -- 0+ transition in oriented B12 and N12 was investigated. In this connection, investigation on the weak magnetism to include all higher order corrections for the evaluation of the spectral shape factors was performed. Other works carried out by the author and his collaborators are also explained. (Kato, T.)

  11. Applying tracer techniques to NPP liquid effluents for estimating the maximum concentration of soluble pollutants in a man-made canal

    International Nuclear Information System (INIS)

    Full text: The possibility of a contamination agent being accidentally or intentionally spilled upstream from a water supply is a constant concern to those diverting and using water from a channel. A method of rapidly estimating the travel-time or dispersion is needed for pollution control or warning system on channels where data are scarce. Travel-time and mixing of water within a stream are basic streamflow characteristics needed in order to predict the rate of movement and dilution of pollutants that could be introduced in the stream. In this study we propose using tritiated liquid effluents from CANDU type nuclear power plant as a tracer, to study hydrodynamics on Danube-Black Sea Canal. This canal is ideal for this kind of study, because wastewater evacuations occur occasionally due to technical operations of nuclear power plant. Tritiated water can be used to simulate the transport and dispersion of solutes in Danube-Black Sea Canal because they have the same physical characteristics as the water. Measured tracer-response curves produced from injection of a known amount of soluble tracer provide an efficient method of obtaining the necessary data. This method can estimate: (1) the rate of movement of a solute through the canal reach: (2) the rate of peak attenuation concentration of a conservative solute in time; and (3) the length of time required for the solute plume to pass a point in the canal. This paper presents the mixing length calculation for particular conditions (lateral branch of the canal, and lateral injection of wastewater from the nuclear power plant). A study of published experimentally-obtained formulas was used to determine proper mixing length. Simultaneous measurements in different locations of the canal confirm the beginning of the experiment. Another result used in a further experiment concerns the tritium level along the Danube-Black Sea Canal. We measured tritium activity concentration in water sampled along the Canal between July

  12. Nuclear-powered infrared surveillance satellite study

    International Nuclear Information System (INIS)

    A study of the applicability of nuclear power to the Deep Space Surveillance System using long wave infrared detectors was conducted. Two possibilities are explored: a hybrid approach, in which nuclear heat sources are used to drive the cryogenic refrigerators, with the remainder of the power provided by a solar-array/battery system; and an all-nuclear approach. The former results in roughly halving the electric power requirements of the satellite, with weight reductions of 5 to 15 percent. The latter permits a monolithic spacecraft design approach with resultant design simplifications and dynamic stability/control advantages, as well as projected weight reductions of 15 to 20 percent as compared to the all-solar design approach. The spacecraft power requirements of 1000 to 1500 watts (e) are within the primary range of the nuclear-dynamic systems currently in development

  13. Feasibility study on nuclear floating island (NUFIS)

    Energy Technology Data Exchange (ETDEWEB)

    Murata, H.; Taketani, K. (Japan Atomic Energy Research Inst., Tokai, Ibaraki. Tokai Research Establishment); Morozumi, M.; Katayama, M.

    1981-02-01

    Under the present oil demand/supply situation, oil consumption must be reduced in Japan, implying the reliance on nuclear energy in future. The siting for nuclear power plants is limited, however, because of the dense population; there must emerge a new concept in this connection. Feasibility of a nuclear floating island (NUFIS) has been studied. The NUFIS is located about 20 km offshore with sea depth about 150 m and has a 1,200 MWe PWR plant on a 140 m x 140 m floating platform, with displacement about 298,000 t. It is technologically feasible, and the platform is stable enough to build the power plant and its associated facilities on it. It is possible to construct a nuclear floating center offshore of Japan, which comprises VHTR, FBR, fuel reprocessing and fabrication plants.

  14. Feasibility study on nuclear floating island (NUFIS)

    International Nuclear Information System (INIS)

    Under the present oil demand/supply situation, oil consumption must be reduced in Japan, implying the reliance on nuclear energy in future. The siting for nuclear power plants is limited, however, because of the dense population; there must emerge a new concept in this connection. Feasibility of a nuclear floating island (NUFIS) has been studied. The NUFIS is located about 20 km offshore with sea depth about 150 m and has a 1,200 MWe PWR plant on a 140 m x 140 m floating platform, with displacement about 298,000 t. It is technologically feasible, and the platform is stable enough to build the power plant and its associated facilities on it. It is possible to construct a nuclear floating center offshore of Japan, which comprises VHTR, FBR, fuel reprocessing and fabrication plants. (author)

  15. A Study on the Nuclear Foreign Policy

    International Nuclear Information System (INIS)

    It is of the utmost importance in the peaceful use and development of nuclear energy to respond in a timely manner to the changes of international nuclear communities. This study were carried focused on the trends of international movements related to nuclear non-proliferation regime and major trends in the international bi- or multi-lateral technical cooperation activities. This study investigates the major changes of international technical cooperation focusing on nuclear functional organizations, IAEA and OECD/NEA which become competent and important in the international technical cooperation. 9.11 terror and international illegal trafficking of A. Q. Khan network caused the strengthening of international nonproliferation regimes and international efforts and measures against threat of nuclear terror and this movement will kept in the international communities afterwards with GTRI, G8 action plan, UN resolution of WMD and ratification and application of additional protocol of IAEA safeguards agreement into member countries. Upgrade of nuclear diplomatic and technical networks and activities are required to secure the national rights and dignity in the international communities in effective and systematic manners through the enlarged participation and contribution of the national experts to working groups activities of IAEA and OECD/NEA together

  16. Study of nuclear multifragmentation induced by ultrarelativistic μ-mesons in nuclear track emulsion

    Science.gov (United States)

    Artemenkov, D. A.; Bradnova, V.; Firu, E.; Kornegrutsa, N. K.; Haiduc, M.; Mamatkulov, K. Z.; Kattabekov, R. R.; Neagu, A.; Rukoyatkin, P. A.; Rusakova, V. V.; Stanoeva, R.; Zaitsev, A. A.; Zarubin, P. I.; Zarubina, I. G.

    2016-02-01

    Exposures of test samples of nuclear track emulsion were analyzed. The formation of high-multiplicity nuclear stars was observed upon irradiating nuclear track emulsions with ultrarelativistic muons. Kinematical features studied in this exposure of nuclear track emulsions for events of the muon-induced splitting of carbon nuclei to three α-particles are indicative of the nuclear-diffraction interaction mechanism.

  17. Nuclear Power Options Viability Study. Volume 3. Nuclear discipline topics

    International Nuclear Information System (INIS)

    Innovative reactor concepts are described and evaluated in accordance with criteria established in the study. The reactors to be studied were chosen on the basis of three ground rules: (1) the potential for commercialization between 2000-2010, (2) economic competiveness with coal-fired plants, and (3) the degree of passive safety in the design. The concepts, classified by coolants, were light water reactors, liquid metal reactors, and high temperature reactors, and most were of modular design. All the concepts appear to be potentially viable in the time frame selected, but the information available is not adequate for a definitive evaluation of their economic competitiveness. This volume primarily reports in greater detail on several topics from the study. These are: Construction, Economics, Regulation, Safety and Economic Risk, Nuclear Waste Transportation and Disposal, and Market Acceptance. Although treated generically, the topics are presented in the context of the reactor concepts of the study

  18. Evaluation of dentin cleansing by a detergent derived from castor oil (Ricinus communis) used as root canal irrigant: a scanning electron miscroscopy study

    OpenAIRE

    Letícia Molteni Aguiar; Lilian Eiko Maekawa; Adriana Chung; Maria Renata Giazzi Nassri

    2010-01-01

    Introduction and objective: To evaluate, by scanning electron microscopy (SEM), the cleaning of root canal walls after biomechanical preparation and irrigation with castor oil (Endoquil®) and 0.5% sodium hypochlorite (NaOCl). Material and methods: Fifteen maxillary incisors were subjected to standardized root canal instrumentation with different irrigants (n = 5): G1 – Endoquil; G2 – 0.5% NaOCl; G3 – saline solution (control). After instrumentation, the teeth were prepared for SEM analysis (...

  19. 利用下颌数字成像曲面断层X线片进行下颌管形态研究%Morphometric study on mandibular canal with digital image of orthopanotomography

    Institute of Scientific and Technical Information of China (English)

    朱东望; 李世芬; 李冀云; 王雨生; 卢建慧

    2001-01-01

    Objective: To study the position and course of the mandibular canal. Methods:Measurements of the position and course of mandibular canal, were carried out on 50 mature mandibles, 39 being dentale and 11 edentale, and digital image of orthopanotomographical pictures were taken. Results: 1.Position of the mental foramen.2. Position of the mandibular foramen. 3. Position and course of the mandibular canal were obtained. Conclusion: Measurement of the position and course of mandibular canal with digital image of orthopanotomography is simple and accurate for directing clinical diagnosis and treatment.%目的:研究下颌骨形态和行径。方法:利用50例离体下颌骨数字成像曲面断层X线片结合离体下颌骨进[摘要]目的:研究下颌骨形态和行径。方法:利用50例离体下颌骨数字成像曲面断层X线片结合离体下颌骨进行测量。结果:测得颏孔位置,下颌孔位置及下颌管位置和行径。结论:下颌数字成像曲面断层X线片可较好地反映下颌管位置和行径,有较高的临床参考价值。

  20. Comparison of two endodontic handpieces during the preparation of simulated root canals.

    Science.gov (United States)

    Smith, R B; Edmunds, D H

    1997-11-01

    The objective of this in vitro study was to compare and assess two endodontic handpieces during the preparation of simulated root canals. One hundred and sixty simulated root canals in clear resin blocks, of two angles and positions of curvature, were prepared using either Shaper files activated by the MM1500 Sonic Air handpiece (Micro-Mega, Besançon, France) or Excalibur files activated by the W & H Excalibur 969 handpiece (W & H, Bürmoos, Austria). Files of 21-mm or 25-mm length were used. When preparing the canals, the files were used either in line with or perpendicular to the canal curvature. Preparation of the canals was carried out using a technique described in the manufacturers' literature. A variety of parameters were used to compare the handpieces, including an assessment of the canal preparation time, the deformation or fracture of instruments, loss of canal length, weight loss from the resin blocks and the overall postpreparation canal shape. Both handpieces provided an efficient and easy method of preparing and shaping the root canal with little operator fatigue. The MM1500 Sonic Air handpiece took significantly more time (P canals and was associated with both more loss of working length (P canals. The MM1500 Sonic Air handpiece created significantly more aberrations than the Excalibur handpiece (P danger zone and coronal narrow). The effects of the variables, canal curvature, file length and the plane of use of the file, on the performance of the handpieces, were also assessed. PMID:9588976

  1. Theoretical studies in nuclear physics

    International Nuclear Information System (INIS)

    This report discusses: microscopic imaginary optical potential; isospin effects and charge exchange; multistep inelastic and charge exchange scattering; momentum space proton scattering; pion scattering from nuclei; antiproton studies; antikaons-nucleon interactions; and quantum mechanics. 11 refs

  2. Study on industrial utilization of nuclear heat

    International Nuclear Information System (INIS)

    In this study, we investigated industrial systems using nuclear heat directly as well as generating electricity. At first, we surveyed the design examples of nuclear heat utilization plants by HTGR in each country and surveyed typical complexes in Japan. On the basis of surveys, we selected the Co-generation system in a chemical plant and the coal gasification system in an ammonia synthesis plant as the industrial system using nuclear heat and designed those systems and clarified the system concept of nuclear heat utilization plants. About the coal gasification system, we could improve the heat utilization efficiency of secondary helium gas by the two-stage coal gasifier. Then we discussed subjects for the realization of such as the nuclear heat industrial utilization, and we showed that nuclear heat utilization systems could compete with conventional systems about the economical field on condition that those conventional systems should install decarburization facilities. In addition, we showed the prospects of atomic energy complexes and prepared data for estimating the select system by the energy model. (author)

  3. TWO CANALS IN MAXILLARY FIRST MOLAR: A RARE DENTAL ENTITY

    Directory of Open Access Journals (Sweden)

    Dileep

    2016-01-01

    Full Text Available Root anatomy studies were divided into laboratory studies (In-Vitro, clinical root canal system anatomy studies (In vivo and clinical case reports of anomalies. Over 95% (95.9% of maxillary first molars had three roots and 3.9% had two roots. The incidence of fusion of any two or three roots was approximately 5.2%. Conical and C-shaped roots and canals were rarely found (0.12%.The fusion of the two buccal roots has the prevalence of 0.4% in maxillary first molars. Nevertheless, presence of only one buccal root with one canal is extremely rare.

  4. Spinal canal stenosis; Spinalkanalstenose

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-11-15

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

  5. Dynamical studies of nuclear multifragmentation

    International Nuclear Information System (INIS)

    We review some dynamical approaches developed by our group to study multifragmentation of nuclei. We first investigate the problem of disassembly of hot and compressed nuclei. We show that multifragmentation occurs at low density as a consequence of the fluctuations of the mean field. The magnitude of the fluctuations is evaluated using percolation methods (lattice percolation or restructured aggregation). The dynamical expansion of the nucleus is studied either using a self consistent Thomas Fermi approach or a simple extended liquid drop. Finally, introducing a preequilibrium model to describe the first phase of the collision between two heavy ions, we use the preceeding investigations to calculate multifragmentation excitation functions. (orig.)

  6. Dynamical studies of nuclear multifragmentation

    International Nuclear Information System (INIS)

    We review some dynamical approaches developed by our group to study multifragmentation of nuclei. We first investigate the problem of disassembly of hot and compressed nuclei. We show that multifragmentation occurs at low density as a consequence of the fluctuations of the mean field. The magnitude of the fluctuations is evaluated using percolation methods (lattice percolation or restructured aggregation). The dynamical expansion of the nucleus is studied either using a self consistent Thomas Fermi approach or a simple extended liquid drop. Finally, introducing a preequilibrium model to describe the first phase of the collision between two heavy ions, we use the preceding investigations to calculate multifragmentation excitation functions

  7. Dynamical studies of nuclear multifragmentation

    Energy Technology Data Exchange (ETDEWEB)

    Ngo, C.; Boisgard, R.; Cerruti, C.; Leray, S.; Spina, M.E.; Desbois, J.; Ngo, H.; Nemeth, J.; Barranco, M.

    1989-05-01

    We review some dynamical approaches developed by our group to study multifragmentation of nuclei. We first investigate the problem of disassembly of hot and compressed nuclei. We show that multifragmentation occurs at low density as a consequence of the fluctuations of the mean field. The magnitude of the fluctuations is evaluated using percolation methods (lattice percolation or restructured aggregation). The dynamical expansion of the nucleus is studied either using a self consistent Thomas Fermi approach or a simple extended liquid drop. Finally, introducing a preequilibrium model to describe the first phase of the collision between two heavy ions, we use the preceeding investigations to calculate multifragmentation excitation functions.

  8. Comparison of Bacterial Leakage between 3 Different Root Canal Obturation Techniques in Oval Shaped Canals

    Directory of Open Access Journals (Sweden)

    Eshagh-ali Saberi

    2014-06-01

    Full Text Available Introduction: The purpose of this study was to evaluate the sealing ability of 3 obturation techniques in oval-shaped canals by bacterial leakage assessment. Methods: Sixty mandibular incisors with oval canals were selected after providing buccolingual and mesiodistal radiographs. The teeth were sectioned at a 10 mm distance from the apex. After instrumentation, the teeth were divided into 3 groups and the canals in the three groups were obturated with lateral condensation (G1, warm vertical condensation (G2 and thermoplasticized injectable gutta percha (G3. The teeth were exposed to human saliva. Observing the turbidity of the BHI broth for a period of 63 days the number of days required for the complete contamination of root canals was recorded. The data were analyzed using descriptive statistical methods and Kruskal-Wallis test with SPSS statistical software. Results: Warm vertical condensation (G2 needed a significantly greater average time for leakage than the two other methods. No significant differences were found between lateral condensations and thermoplasticized injectable G.P techniques. Conclusion: warm vertical condensation provides a better seal against bacterial leakage than lateral condensation and obtura II method in obturating oval-canals.

  9. 三种器械用于磨牙弯曲根管预备的临床评价%A Clinical study of three instruments in preparation of curved root canals

    Institute of Scientific and Technical Information of China (English)

    王天; 李桂红

    2013-01-01

    目的:评价不锈钢K锉、机用ProTaper和机用Safe-Sider预备磨牙弯曲根管的临床疗效.方法:选取因牙髓炎或根尖周炎需要进行根管治疗的磨牙180颗(413个根管),随机分为K-file组、ProTaper组和Safe Sider组,每组60颗牙.分别用不锈钢K锉、机用ProTaper和机用Safe Sider进行根管预备.三组均采用冷牙胶侧方加压技术充填根管.记录三组病例根管预备时间和术后并发症发生情况,根据治疗前、中、后的X线片评价根管预备和充填效果.结果:机用ProTaper、机用Safe Sider分别与不锈钢K锉在根管预备时间、根管成形以及充填效果方面在统计学上有显著性差异(P0.05).结论:机用ProTaper和机用Safe Sider预备磨牙弯曲根管时能较好地保持原有根管形态,省时省力,术后反应少.%Objective: To evaluate the clinical effect of K-file 、 ProTaper and SafeSider in preparation of curved molar root canals. Method: A total of 180 teeth which needed endodontic treatment were selected and randomly divided into 3 groups with 60 teeth in each group:K-file group、ProTaper group and SafeSider group. The root canals were prepared with 3 instruments respectively. All canals were obturated using lateral condensation technique. The efficacy of canal preparation and obturation by X-ray before, during and after operation was analyzed.Result: Statistically significant difference was found in mean working time, shaping curved molar canals and exact root canal obturation between K-file group、ProTaper group or SafeSider group. No Statistically significant difference was found in mean working time, shaping curved molar canals and exact root canal obturation between ProTaper group and SafeSider group. Conclusion: ProTaper and SafeSider tested in this study are effective and time-saving in shaping curved molar canals, it also caused less post-operative pain. The results indicated both ProTaper and SafeSider were comparable to optimally enlarge root

  10. The shape of the human lumbar vertebral canal A forma do canal vertebral lombar humano

    Directory of Open Access Journals (Sweden)

    Edmundo Zarzur

    1996-09-01

    Full Text Available Literature on the anatomy of the human vertebral column characterizes the shape of the lumbar vertebral canal as triangular. The purpose of the present study was to determine the precise shape of the lumbar vertebral canal. Ten lumbar vertebral columns of adult male cadavers were dissected. Two transverse sections were performed in the third lumbar vertebra. One section was performed at the level of the lower border of the ligamenta flava, and the other section was performed at the level of the pedicles. The shape of the lumbar vertebral canal at the level of the pedicles tends to be oval or circular, whereas the shape of the lumbar vertebral canal at the level of the lower border of the ligamenta flava is triangular. Thus, the shape of the human lumbar vertebral canal is not exclusively triangular, as reported in the literature. It is related to the level of the transversal section performed on the lumbar vertebra. This finding should be taken into consideration among factors involved in the spread of solutions introduced into the epidural space.A literatura sobre a anatomia da coluna vertebral descreve como sendo triangular o formato do canal vertebral na região lombar. O objetivo deste estudo é determinar a real forma do canal da coluna vertebral lombar.Dez colunas vertebrais de cadáveres de homens adultos foram dissecadas. Dois cortes transversais foram executados na terceira vértebra lombar. Um corte foi feito no nível das bordas inferiores de dois ligamentos amarelos vizinhos e o outro corte foi transversal, no nível dos pedículos. A forma do canal vertebral variou: no nível dos pedículos ela tende a ser oval ou circular e junto às bordas inferiores dos ligamentos amarelos passa a ser triangular. Portanto, a forma do canal vertebral lombar não é somente triangular; ela depende do nível em que se faz o corte transversal da vértebra. Estes achados devem ser levados em consideração entre os fatores envolvidos na difusão das

  11. Condensed matter studies by nuclear methods

    International Nuclear Information System (INIS)

    The separate abstract was prepared for 1 of the papers in this volume. The remaining 13 papers dealing with the use but not with advances in the use of nuclear methods in studies of condensed matter, were considered outside the subject scope of INIS. (M.F.W.)

  12. Nuclear structure studies at intermediate energies:

    International Nuclear Information System (INIS)

    This paper discusses progress on studies on nuclear structure at the University of Minnesota. Some of the topics discussed are: nucleon-nucleon interactions, high spin stretched states, deformed and transition nuclei, giant resonances, measurement of spin observables, pion scattering, delta resonances, and electron scattering

  13. Nuclear transformations studies in selenium isotopes

    International Nuclear Information System (INIS)

    A compilation is made with regard to the chemical effects produced by nuclear transformations, such as the chemical effects of the beta decay and the chemical effects of the reaction (n,γ) in selenium radioisotopes. As a particular case the chemical effect of the isomeric transition of sup(81m)Se(VI) in potassium selenate crystals marked with radioactive selenium is studied experimentally and the method of adsorption in activated carbon is applied for the analytical separation of the traces of the nuclear isomer tetravalent sup(81b)Se(IV) of one fraction which contains the mixture of the selenium radioisotopes. (author)

  14. A study of nuclear power in France

    International Nuclear Information System (INIS)

    It is stated that the purpose of the study is to identify and explain, for a British audience, what the author perceives to be the combination of forces and events that have led France to adopt the most thrustful nuclear programme in the world at the present time. The subject is discussed under the headings: nuclear perspectives (energy needs and supplies - forecasts and programmes); the national interest (government policies in relation to energy; reactor types - gas-graphite and LWR); the structure of the French nuclear industry; the State (the French corps of scientists; the existence of an Administrative Elite; the role of the State and its function in industrial management); decision making; the CEA (Commissariat a l'Energie Atomique); Electricite de France; electricity growth and prices; financing the expansion; the international dimension (cooperation). (author)

  15. Project safety studies - nuclear waste management (PSE)

    International Nuclear Information System (INIS)

    The project 'Safety Studies-Nuclear Waste Management' (PSE) is a research project performed by order of the Federal Minister for Research and Technology, the general purpose of which is to deepen and ensure the understanding of the safety aspects of the nuclear waste management and to prepare a risk analysis which will have to be established in the future. Owing to this the project is part of a series of projects which serve the further development of the concept of nuclear waste management and its safety, and which are set up in such a way as to accompany the realization of that concept. This report contains the results of the first stage of the project from 1978 to mid-1981. (orig./RW)

  16. A comparative evaluation of smear layer removal by using edta, etidronic acid, and maleic acid as root canal irrigants: An in vitro scanning electron microscopic study

    Directory of Open Access Journals (Sweden)

    Aby Kuruvilla

    2015-01-01

    Full Text Available Aim: The purpose of this study is to evaluate and compare the efficacy of 17% EDTA, 18% etidronic acid, and 7% maleic acid in smear layer removal using scanning electron microscopic image analysis. Materials and Methods: Thirty, freshly extracted mandibular premolars were used. The teeth were decoronated to obtain working length of 17mm and instrumentation up to 40 size (K file with 2.5% NaOCl irrigation between each file. The samples were divided into Groups I (17% ethylenediaminetetraacetic acid (EDTA, II (18% etidronic acid, and III (7% maleic acid containing 10 samples each. Longitudinal sectioning of the samples was done. Then the samples were observed under scanning electron microscope (SEM at apical, middle, and coronal levels. The images were scored according to the criteria: 1. No smear layer, 2. moderate smear layer, and 3 heavy smear layer. Statistical Analysis: Data was analyzed statistically using Kruskal-Wallis analysis of variance (ANOVA followed by Mann-Whitney U test for individual comparisons. The level for significance was set at 0.05. Results: The present study showed that all the three experimental irrigants removed the smear layer from different tooth levels (coronal, middle, and apical. Final irrigation with 7% maleic acid is more efficient than 17% EDTA and 18% etidronic acid in the removal of smear layer from the apical third of root canal.

  17. The Comparative Efficacy of Different Files in The Removal of Different Sealers in Simulated Root Canal Retreatment- An In-vitro Study

    Science.gov (United States)

    Kanaparthy, Aruna

    2016-01-01

    Introduction Root canal treatment enjoys a high success rate all over the world and has saved billions of teeth from extraction. However, there are instances of failure, the main causes being insufficient cleaning and inadequate obturation. In such cases the most conservative treatment option would be non-surgical retreatment. It requires regaining access to the entire root canal system through removal of the original root canal filling thus permitting further cleaning and re- obturation. Removal of gutta-percha and sealer becomes a critical step to gain access to the root canal system, remove necrotic tissue debris, bacteria and infected dentin. Aim To compare and evaluate the efficacy of manual hand Hedstrom files and two rotary retreatment file systems ProTaper Universal retreatment files and MtwoR (retreatment) files in the removal of root canal filling material during root canal retreatment and the influence of the type of sealers zinc oxide eugenol and AH plus on the presence of remaining debris in the reinstrumented canals in the apical, middle and coronal third. Materials and Methods Sixty single rooted human premolar teeth were divided into 3 Groups of 20 teeth each Group I (20 Teeth): prepared using hand K Files, Group II (20 Teeth): prepared using ProTaper rotary system and Group III (20 Teeth): prepared using Mtwo rotary system. In Groups- IA, IIA, IIIA: (10 teeth each) Obturation was done using Zinc Oxide Eugenol sealer and gutta percha. In Groups- IB, IIB, IIIB: (10 teeth each) obturation was done with AH Plus sealer and gutta percha. All the teeth were subjected to retreatment. Groups IA and IB with Hedstrom files, Groups IIA and IIB with ProTaper retreatment files and for Groups IIIA and IIIB with Mtwo retreatment Files. The roots were longitudinally split and were observed under a stereomicroscope for remaining amount of filling material on the canal walls. Statistical analysis was done using One–way ANOVA (Analysis of variance) test and Tukey

  18. Filling of simulated lateral canals using different obturation techniques: analysis through IDA digital radiograph system

    Directory of Open Access Journals (Sweden)

    Clarissa Teles Rodrigues

    2012-09-01

    Full Text Available Introduction: Lateral canals are part of the root canal system and may be related to periodontal-endodontic diseases. The filling techniques that employ thermoplasticized gutta-percha have demonstrated better results in filling lateral canals. Objective: The aim of this study was to evaluate, through digital radiographs, three techniques of root canal obturation (Lateral Condensation, Obtura II System, Tagger’s Hybrid regarding to the ability of filling artificial lateral canals. Material and methods: 30 extracted human lower premolars were used in this study. The crowns were removed and artificial laterals canals were prepared on the coronal, medium and apical thirds of the roots by using a reamer made of a K 10 file. The root canals were instrumented and obturated by the following techniques: Lateral Condensation, Obtura II System, and Tagger’s Hybrid. The teeth were radiographed with IDA digital radiograph system and the filling of the lateral canals was evaluated by scores for further statistical analysis. Results: No significant difference was found in the filling of lateral canals between Lateral Condensation and Obtura II, but a significant difference was found among these two and Tagger’s Hybrid technique. Conclusion: Tagger’s Hybrid technique promoted the highest numbers of obturated lateral canals. In the three groups, the root thirds presenting greater number of filled lateral canals were coronal and middle, regardless of the obturation technique employed.

  19. Discharge Estimation in a Lined Canal Using Information Entropy

    Directory of Open Access Journals (Sweden)

    Yen-Chang Chen

    2014-03-01

    Full Text Available This study applies a new method and technology to measure the discharge in a lined canal in Taiwan. An Acoustic Digital Current Meter mounted on a measurement platform is used to measure the velocities over the full cross-section for establishing the measurement method. The proposed method primarily employs Chiu’s Equation which is based on entropy to establish a constant ratio the relation between the maximum and mean velocities in an irrigation canal, and compute the maximum velocity by the observed velocity profile. In consequence, the mean velocity of the lined canal can be rapidly determined by the maximum velocity and the constant ratio. The cross-sectional area of the artificial irrigation canal can be calculated for the water stage. Finally, the discharge in the lined canal can be efficiently determined by the estimated mean velocity and the cross-sectional area. Using the data of discharges and stages collected in the Wan-Dan Canal, the correlation of stage and discharge is also developed for remote real-time monitoring and estimating discharge from the pumping station. Overall, Chiu’s Equation is demonstrated to reliably and accurately measure discharge in a lined canal, and can serve as reference for future calibration for a stage-discharge rating curve.

  20. Comparison of the Antimicrobial Efficacy of Two Antibiotics Sparfloxacin and Augmentin as Experimental Root Canal Irrigating Solutions against Enterococcus faecalis - An Invitro Study

    Science.gov (United States)

    Venigalla, Bhuvan Shome; Surakanti, Jayaprada Reddy; Thumu, Jayaprakash; Chennamaneni, Krishna Chaitanya; Kalluru, Rama S.

    2016-01-01

    Introduction One of the main goals of endodontic treatment is root canal disinfection and to prevent subsequent chances of reinfection. Adjuvant to instrumentation, root canal irrigants are required to eliminate the bacteria found on the root canal walls and lateral canals within the dentinal tubules. Aim To measure and compare the antibacterial efficacy of two antibiotics as experimental root canal irrigating solutions against Enterococcus faecalis (E. faecalis). Materials and Methods Fifteen Brain Heart Infusion agar plates were inoculated with Enterococcus faecalis-American Type Culture Collection (ATCC) 29212. 5 micrograms (mcg) Sparfloxacin discs, 30mcg Augmentin discs, and sterile paper test discs saturated with 2% Chlorhexidine (CHX), 3% Sodium Hypochlorite (NaOCl) and 5% NaOCl solutions were placed on agar plates. Sodium Chloride 0.9% (NaCl) paper discs were used as controls. Fifteen plates were incubated aerobically at 37°C. Results were expressed as per the terms of the diameter of the inhibition zone. Results Results suggested a statistically significant difference in the zones of inhibition between five irrigating solutions (p < 0.001). Conclusion Although, zones of inhibition were found in all the groups, 5mcg Sparfloxacin and 30mcg Augmentin showed maximum antimicrobial activity against E.faecalis. PMID:27135003

  1. Nuclear decay studies far-from-stability

    International Nuclear Information System (INIS)

    Nuclear decay studies far-from-stability are performed not merely to characterize new isotopes, but to establish an experimental footing for improving our theoretical understanding of nuclear structure and decay. Although progress has been made in explaining low-lying level structure for a broad range of nuclei, transition probabilities are not yet quantitatively understood. The ability to understand nuclei far-from-stability is important to astrophysics for extending r- and s-process calculations to unknown nuclei, and to nuclear engineering for decay-heat calculations. Finally, by studying nuclei far-from-stability, we probe extremes of both decay energy and proton-neutron ratios where unforeseen and important new nuclear properties may be exhibited. The decays of nearly 100 isotopes and isomers have been studied with the OASIS mass-separation facility on-line at the Lawrence Berkeley Laboratory SuperHILAC. These studies have concentrated on neutron-deficient nuclei with 55≤Z≤71 up to A=157 and neutron-rich nuclei with 166≤A≤174. The results of these experiments are combined in this paper with those from many other laboratories to provide insight into systematic trends of beta- and γ-ray transition probabilities near N=82. It is hoped that the smooth systematic trends in these transition probabilities will provide clues towards interpreting the underlying nuclear structure. Nuclei near N=82 and Z=64 are expected to be spherical and should be described by simple Shell Model considerations. Away from the shell closures, deformation sets in which should exhibit itself in the transition probabilities. The Z=64 shell closure is expected to disappear near N=78. The qualitative nature of these phenomena will be discussed

  2. Why should we study nuclear physics?

    International Nuclear Information System (INIS)

    After a brief look at the history of nuclear science and technology in the past hundred years, arguments are given for the study of Nuclear Physics, very different of course from what they were in the middle of the past century. Nuclear physics no longer appears as a good bet to study the strong force. Problems left open by QCD are better addressed by relativistic ion accelerators, RHIC and LHC/Alice. Radioactive Ion Beams have caused a renaissance of experimental nuclear physics. They explore the nuclear equation of state far from the stability valley, discovering new isotopes and new forms of dynamics, such as halo nuclei. They contribute essential data to nuclear astrophysics. They have new applications in medicine and industry. They enjoy strong support all around the world; in Asia, Japan is a leader and Korea and China are joining the club. Nuclear processes are ubiquitous in astrophysics: Big bang nucleosynthesis, Main Sequence stars, evolved stars (Asymptotic Giant Branch and Supernovae). Understanding what is going on requires knowledge from laboratory measurements; at the same time astrophysics gives nuclear physics a laboratory having no equivalent on Earth. Applications of nuclear physics pervade modern societies. Medicine and material sciences, make ample use of radioactive sources and ion beams, as do all branches of agriculture and industry. Accelerators are now commercially available and part of the industrial landscape. Implications on training competent scientists, technicians and engineers are enormous. Particularly crucial are matters of safety. Nuclear Power Plants are a major element of the Vietnamese energy policy in the decades to come. Their safe and efficient operation requires high level skills and competence that cover a broad spectrum of scientific and technical, but also socio-economic and geo-political issues. Nuclear physics must be taught to the young generation in a form that takes proper account of the current scientific

  3. Hood Canal Steelhead - Hood Canal Steelhead Supplementation Experiment

    Data.gov (United States)

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

  4. Effectiveness of different irrigation techniques on smear layer removal in apical thirds of mesial root canals of permanent mandibular first molar: A scanning electron microscopic study

    Directory of Open Access Journals (Sweden)

    Pranav Khaord

    2015-01-01

    Full Text Available Aim: The aim of this study was to compare smear layer removal after final irrigant activation with sonic irrigation (SI, manual dynamic agitation (MDA, passive ultrasonic irrigation (PUI, and conventional syringe irrigation (CI. Materials and Methods: Forty mesial canals of mandibular first molars (mesial roots were cleaned and shaped by using ProTaper system to size F1 and sodium hypochlorite 3% and 17% ethylenediaminetetraacetic acid. The specimens were divided into 4 equal groups (n = 10 according to the final irrigation activation technique: Group 1, PUI; group 2, manual dynamic activation (MDA; group 3, SI; and group 4, control group (simple irrigation. Samples were split longitudinally and examined under scanning electron microscope for smear layer presence. Results: Control groups had the highest smear scores, which showed the statistically significant highest mean score at P < 0.05. This was followed by ultrasonic, MDA, and finally sonic, with no significant differences between them. Conclusions: Final irrigant activation with sonic and MDA resulted in the better removal of the smear layer than with CI.

  5. Comparative evaluation of antimicrobial activity of hydroalcoholic extract of Aloe vera, garlic, and 5% sodium hypochlorite as root canal irrigants against Enterococcus faecalis: An in vitro study

    Directory of Open Access Journals (Sweden)

    Swati Ramesh Karkare

    2015-01-01

    Full Text Available Introduction: Enterococcus faecalis are the most resistant and predominant microorganisms recovered from root canals of teeth where previous treatment has failed. Over the past decade, interest in drugs derived from medicinal plants has markedly increased. In dentistry, phytomedicines has been used as an anti-inflammatory, antibiotic, analgesic, sedative, and also as an endodontic irrigant. In endodontics, because of the cytotoxic reactions of most of the commercial intracanal medicaments and their inability to eliminate bacteria completely from dentinal tubules, the trend is shifting toward use of biologic medication extracted from natural plants. Aim: To compare the antimicrobial efficacy of newer irrigating agents which would probably be as effective or more and at the same time less irritating to the tissues than sodium hypochlorite (NaOCl. The objective of this study was to compare the antimicrobial activity of saturated and diluted (1:1 hydroalcoholic extract of Aloe vera, garlic, and 5% NaOCl against E. faecalis using the commonly used agar diffusion method. Results: Saturated hydroalcoholic extract of A. vera showed the highest zone of inhibition against E. faecalis. NaOCl, which is considered as gold standard, also showed higher zones of inhibition.

  6. Method for Constructing Standardized Simulated Root Canals.

    Science.gov (United States)

    Schulz-Bongert, Udo; Weine, Franklin S.

    1990-01-01

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

  7. Southeastern Utah nuclear-waste-transportation study

    International Nuclear Information System (INIS)

    This report is published as a product of the National Waste Terminal Storage (NWTS) Program. The objective of this program is the development of terminal waste storage facilities in deep stable geologic formations for high-level nuclear waste, including spent fuel elements from commercial power reactors and transuranic nuclear waste for which the Federal Government is responsible. The initial purpose of this study was to analyze and compare possible transport modes and corridors connecting each of four candidate sites in Utah with existing rail lines of the Denver and Rio Grande Western Railroad (D and RG) or the Atchison, Topeka, and Santa Fe Railway (ATSF). The primary use of these routes would be for shipping spent nuclear fuel and other nuclear wastes. During the study, the Gibson Dome area was recommended as the preferred location by the screening process evaluating the four Utah areas. Therefore, this report presents transportation routes to Gibson Dome examining order-of-magnitude capital costs of railroad and heavy haul routes, railroad and heavy haul truck operating costs and environmental factors. The scope of work did not include consideration of using public highways. Information on the other candidate sites and possible routes to them is also presented. 15 figures, 10 tables

  8. Survey study of communities with nuclear facilities

    International Nuclear Information System (INIS)

    The report gives a description of the five Swedish communities that already have nuclear facilities, in order to find the potential for selecting any of these for a future Swedish nuclear waste repository. Only existing, available information has been collected for this report, with the aim to find the interest and need for more detailed localization studies. The following subjects are treated: General data like area, population, industry etc. Communications (road, rail and airports). Existing facilities. Geology. Hydrology. Experiences from rock constructions. Land use, planning, natural reserves etc. Local technical conditions for transport and construction. The following conclusions are drawn: Oskarshamn, Nykoeping and Oesthammar have good geologic potentials and should be candidates for more extensive geologic studies. The geologic potential of Varberg is less well known, and geologic mapping and geophysical measurements are needed. Kaevlinge does not have geologic or technical potentials on par with the other communities, and can be disregarded for further studies. 64 refs, 18 figs

  9. Nuclear structure studies with medium energy probes

    International Nuclear Information System (INIS)

    Progress in the continuing program of experimental research in nuclear structure with medium-energy probes during the year 1979-1980 is reviewed, and the research activities planned for the year 1980-1981 are discussed. In the study of pion-induced reactions emphasis is placed on investigation of isovector characteristics of nuclear excitations and on double charge exchange reactions. Pion production studies form the major part of the program of experiments with proton beams of 400 to 800 MeV at LAMPF. Current emphasis is on the bearing of these investigations on di-baryon existence. The study of high-spin states and magnetic scattering constitute the main goals of the electron scattering program at Bates. Representative results are presented; completed work is reported in the usual publications

  10. Study on the establishment of nuclear education and training network based on the nuclear knowledge management

    International Nuclear Information System (INIS)

    The preservation and succession of nuclear knowledge are essential for the sustainable development of nuclear energy. Nuclear knowledge management is inseparably related with education and training, also should be considered as future oriented activities for the next generation. Nevertheless mankind has enormously benefited worldwide from the use of the nuclear energy over the last half a century, nuclear energy has faced with difficulties from the public. The current nuclear workforce is getting older, less of youth are studying nuclear science and engineering. These issues should be discussed together with the government, research institutes, universities, and industries in terms of the preservation and succession of nuclear knowledge. Therefore, education and training of nuclear technology is requested to develop its role with cooperation of the national level, furthermore of regional and interregional level. This paper provides the methodology of the establishment of a regional network of nuclear education and training based on the nuclear knowledge management

  11. A PET/CT-based Morphometric Study of Spinal Canal in Korean Young Adults: Anteroposterior Diameter from Cervical Vertebra to Sacrum

    OpenAIRE

    Kang, Moo Sung; Park, Jeong Yoon; Chin, Dong Kyu; Kim, Kyung Hyun; Kuh, Sung Uk; Kim, Keun Su; Cho, Yong Eun

    2012-01-01

    Objective To establish normative data for spinal canal AP diameter from cervical vertebra to sacrum in the Korean young and to assess the exposed spinal canal after laminectomy which was related with restenosis by post-laminectomy membrane formation. Methods From PET/CT, axial bone-window CT of 83 young adults (20-29 years) were obtained, and we measured AP diameters of C3, C5, C7, T1, T4, T8, T12, L1, L3, L5 and S1. We also measured exposed AP diameter of C3, C5, C7, T1 and T2 above imaginar...

  12. 三种根管消毒方法疗效的研究%Three kinds of root canal disinfection efficacy study

    Institute of Scientific and Technical Information of China (English)

    袁慧娟

    2012-01-01

    目的:探讨微波技术,超声波根管预备技术及药物甲醛甲酚在根管消毒中的疗效.方法:采用细菌培养法检测和比较微波、超声波及甲醛甲酚(FC)的根管消毒效果,并对根管充填后1周和1年后三者的疗效作评价分析.结果:细菌学检测显示微波、超声波技术均能较好杀灭需氧菌和厌氧菌,且优于FC药物消毒,效果有显著性差异(P<0.01).1周和1年后的微波和超声波技术的成功率均高于FC法.结论:微波技术、超声波根管预备技术在根管消毒上效果确切,可替代FC法作根管充填前的根管消毒.%Objective To investigate the technique of microwave,ultrasonic root canal preparation techniques and drugs of formocresol in root canal disinfection efficacy. Methods The bacterial culture method for the detection and comparison of microwave,ultrasonic and formocresol (FC) of the root canal disinfection effect,and the root canal filling after one week and one year after the three assessment of curative effect analysis. Results Bacteriology examination showed that the microwave,ultrasonic technique can be used to kill aerobes and anaerobes,and superior to that of FC drugs disinfection effect.there was significant difference (P<0.01).One week and one year after the microwave and ultrasonic technology success rates are higher than those of FC method. Conclusion Microwave.ultrasonic root canal preparation techniques in root canal disinfection on the exact effect.can replace FC as root canal filling of root canal disinfection.

  13. Ultrasonic cleaning of root canals

    Science.gov (United States)

    Verhaagen, Bram; Boutsioukis, Christos; Jiang, Lei-Meng; Macedo, Ricardo; van der Sluis, Luc; Versluis, Michel

    2011-11-01

    A crucial step during a dental root canal treatment is irrigation, where an antimicrobial fluid is injected into the root canal system to eradicate all bacteria. Agitation of the fluid using an ultrasonically vibrating miniature file has shown significant improvement in cleaning efficacy over conventional syringe irrigation. However, the physical mechanisms underlying the cleaning process, being acoustic streaming, cavitation or chemical activity, and combinations thereof, are not fully understood. High-speed imaging allows us to visualize the flow pattern and cavitation in a root canal model at microscopic scales, at timescales relevant to the cleaning processes (microseconds). MicroPIV measurements of the induced acoustic streaming are coupled to the oscillation characteristics of the file as simulated numerically and measured with a laser vibrometer. The results give new insight into the role of acoustic streaming and the importance of the confinement for the cleaning of root canals.

  14. Mandibular first molar with three distal canals

    OpenAIRE

    Shweta Jain

    2011-01-01

    With the increasing number of reports of aberrant root canal morphology, the clinician needs to be aware of the variable anatomy. Various case reports have been published with the finding of middle mesial canal in mandibular first molar, however finding of middle distal canal in distal root of mandibular first molar is rare. This case report describes root canal treatment of two rooted mandibular first molar with five root canals (three in distal and two in mesial root), and Sert and Bayirli ...

  15. Comparative Study of Hand Use Stainless Steel Files and Nickel Titanium Rotary Instruments in Root Canal Preparation%手动及机用器械根管预备效果的临床对比分析

    Institute of Scientific and Technical Information of China (English)

    王丽娟

    2015-01-01

    目的:对比研究手用不锈钢扩管锉与Mtwo根扩系统根管预备术后的临床效果。方法选择62例慢性牙髓炎或慢性根尖周炎需行根管治疗的患牙共146个根管,分别用手动不锈钢K锉及Mtwo镍钛锉行根管预备,甲醛甲酚棉球暂封1周观察术后疼痛发生率。结果手动不锈钢锉组8例17个根管术后疼痛,Mtwo组3例6个根管术后疼痛,经χ2方检验统计学差异明显。结论 Mtwo机用镍钛锉预备根管临床效果明显优于手动不锈钢锉,值得临床推广使用。%Objective A comparative study of hand use stainless steel tube expandingclinical effect of file and the Mtwo root ex⁃pansion system root canal preparation after operation. Methods To selecrt clinical 62 teeth with chronic pulpitis or chronic periapical periodontitis need for root canal treatment, total 146 root canals, respectively using stainless steel files and Mtwo nickel titanium files for root canal preparation, formocresol cotton temporarily closed for a week to observethe incidence of postoperative pain. Results Hand use stainless steel file group of pain in 8 teeth with 17 root canals after operation, Mtwo group of pain in 3 teeth with 6 root ca⁃nals after operation, after X2 square test,there were statistically significant differences. Conclusions The clinical effect of nickel titani⁃um rotary instruments in root canal preparation is better than manual stainless steel file . Mtwo machine is worthy of clinical use.

  16. Retromolar Canal Associated with Age, Side, Sex, Bifid Mandibular Canal, and Accessory Mental Foramen in Panoramic Radiographs of Brazilians

    OpenAIRE

    Capote, Ticiana Sidorenko de O.; Marcela de Almeida Gonçalves; Juliana Álvares Duarte Bonini Campos

    2015-01-01

    Background. The retromolar canal (RMC) is an anatomical variation that can cause complications in dental procedures. Method. The RMC was evaluated according to age, sex, and presence of accessory mandibular canal and accessory mental foramen, on both sides in 500 panoramic radiographs, belonging to individuals at the age of 7 to 20 years. The associations of interest were studied through Fisher's Exact Test and Pearson's Chi-Square Test, and the correlation was studied through Pearson's Corre...

  17. Synergistic growth effect among bacteria recovered from root canal infections

    Directory of Open Access Journals (Sweden)

    Gil Moreira Júnior

    2011-09-01

    Full Text Available The objective of this study was to determine the ecological relationships between bacterial species that colonize infected root canals. Root canal bacteria recovered from one patient with pulp canal necrosis were evaluated in vitro for synergistic and antagonistic activities determined by mono and co-culture growth kinetics and the production of bacteriocin-like substances using the double layer diffusion method. Peptostreptococcus prevotii triggered a significant increase of Fusobacterium nucleatum growth, while the former bacteria did not affect the growth of P. prevotii. The bacterial species did not produce antagonism activity against itself or against any of the other two species. Despite many studies have demonstrated the capability of root canal microorganisms to produce antagonistic substances, these in vitro experimental tests show the synergistic effect of P. prevotii on the growth of F. nucleatum.

  18. Connected analysis nuclear-thermo-hydraulic of parallel channels of a BWR reactor using distributed computation; Analisis acoplado nuclear-termohidraulico de canales paralelos de un reactor BWR empleando computacion distribuida

    Energy Technology Data Exchange (ETDEWEB)

    Campos Gonzalez, Rina Margarita

    2007-07-15

    developed work only concentrates in the reactor core, but taking advantage of the modularity that PVM offers, it is possible to add component such as separators and steam dryers, lines of steam and feed water to obtain a model of a complete closed circuit. The applications concentrate mainly in the training of personnel in the phenomenology of the BWR, and as an investigation tool in the study of the dynamics of BWR reactors. The oscillations out of phase study presents challenges at the moment as are the explanation of the variation of the neutral line with time, non azimuthal but axial oscillations out of phase, etc. So far a first model oriented in this direction is at hand. [Spanish] Este trabajo consiste en la integracion de tres modelos desarrollados previamente los cuales se encuentran ampliamente descritos en la literatura: modelo del canal termohidraulico, modelo de la neutronica modal y el modelo de los lazos de recirculacion. La herramienta utilizada para este acoplamiento de modelos es el sistema PVM, Parallel Virtual Machine, que permitio paralelizar el modelo mediante el concepto de computacion distribuida. La finalidad de hacer este acoplamiento de modelos es la de obtener una herramienta mas completa que represente mejor la configuracion real y la fenomenologia del nucleo de un reactor BWR, obteniendo asi mejores resultados. Ademas mantener la flexibilidad de mejorar el modelo resultante en cualquier momento, ya que los modelos muy complejos o sofisticados resultan dificiles de mejorar siendo imposible modificar las ecuaciones que utilizan y pueden incluir variables que no son de importancia primaria en el problema tratado o que enmascaren relaciones entre variables debido al exceso de resultados. Tambien el mantener la flexibilidad de agregar modelos de componentes o sistemas del reactor BWR, todo esto dependiendo de las necesidades del modelado. Se eligio a la planta sueca Ringhals para caracterizar el modelo acoplado resultante por contar con un Benchmark

  19. Assessment of risks of stenosis of the anal canal during a prostatic radiotherapy; evaluation des risques de stenose du canal anal lors de la radiotherapie prostatique

    Energy Technology Data Exchange (ETDEWEB)

    Almokhles, H.; Pan, Q.; Calitchi, E.; Diana, C.; Muresan, M.; Jiang, M.W.; Wu, J.F.; Wang, X.W.; Lu, H.J.; Lagrange, J.L. [Hopital Henri-Mondor, Creteil (France)

    2011-10-15

    The authors report a study which aimed at assessing the late tolerance of a prostatic irradiation at the rectum and anal canal level. They assessed the length of the rectum and of the anal canal after prostate irradiation or surgery in patients who suffered from a prostate adenocarcinoma. Data of 154 patients have been analyzed regarding the number of cases of stenosis of rectum or anal canal. They highlight the importance of the irradiated length and dose level. Short communication

  20. A study on international nuclear organizations and conventions for the globalization of Korean nuclear community

    International Nuclear Information System (INIS)

    The objective of this study is to analyze the current status of international nuclear organizations and conventions in systems perspective and suggest national strategies for utilizing them for the globalization of Korean nuclear community. This study analyzes the current status of international nuclear organizations such as IAEA(International Atomic Energy Agency) and international nuclear conventions related to nuclear accidents, nuclear liability, physical protection or nuclear safety. Based on the analysis, this study suggests national strategies, in general and specific terms, to utilize international nuclear organizations and conventions for the globalization of Korean nuclear community. Separately from this report this study publishes 'IAEA Handbook', which contains all about IAEA such as statute, membership, organizational structure, main activities, finance and budget, etc.. 9 tabs., 2 figs., 35 refs. (Author)

  1. Assessment of bifid and trified mandicular canals using cone beam computed tomography

    International Nuclear Information System (INIS)

    To investigate the prevalence of bifid and trifid mandibular canals using cone-beam computed tomography (CBCT) images, and to measure their length, diameter, and angle. CBCT images of 500 patients, involving 755 hemi-mandibles, were used for this study. The presence and type of bifid mandibular canal was evaluated according to a modified classification of Naitoh et al. Prevalence rates were determined according to age group, gender, and type. Further, their diameter, length, and angles were measured using PACSPLUS Viewer and ImageJ 1.46r. Statistical analysis with chi-squared and analysis of variance (ANOVA) tests was performed. Bifid and trifid mandibular canals were found in 22.6% of the 500 patients and 16.2% of the 755 sides. There was no significant difference between genders and among age groups. The retromolar canal type accounted for 71.3% of the identified canals; the dental canal type, 18.8%; the forward canal type, 4.1%; and the trifid canal type, 5.8%. Interestingly, seven cases of the trifid canal type, which has been rarely reported, were observed. The mean diameter of the bifid and trifid mandibular canals was 2.2 mm and that of the main mandibular canal was 4.3 mm. Their mean length was 16.9 mm; the mean superior angle was 149.2 degrees, and the mean inferior angle was 37.7 degrees. Bifid and trifid mandibular canals in the Korean population were observed at a relatively high rate through a CBCT evaluation, and the most common type was the retromolar canal. CBCT is suggested for a detailed evaluation of bifid and trifid mandibular canals before mandibular surgery.

  2. Assessment of bifid and trified mandicular canals using cone beam computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Rashsyren, Oyuntugs [Dept. of Oral and Maxillofacial Radiology, School of Dentistry, Mongolian National University Medical Science, Ulaanbaatar (United States); Choi, Jin Woo; Han, Won Jeong; Kim Eun Kyung [Dept. of Oral and Maxillofacial Radiology, Dankook University College of Dentistry, Cheonan (Korea, Republic of)

    2014-09-15

    To investigate the prevalence of bifid and trifid mandibular canals using cone-beam computed tomography (CBCT) images, and to measure their length, diameter, and angle. CBCT images of 500 patients, involving 755 hemi-mandibles, were used for this study. The presence and type of bifid mandibular canal was evaluated according to a modified classification of Naitoh et al. Prevalence rates were determined according to age group, gender, and type. Further, their diameter, length, and angles were measured using PACSPLUS Viewer and ImageJ 1.46r. Statistical analysis with chi-squared and analysis of variance (ANOVA) tests was performed. Bifid and trifid mandibular canals were found in 22.6% of the 500 patients and 16.2% of the 755 sides. There was no significant difference between genders and among age groups. The retromolar canal type accounted for 71.3% of the identified canals; the dental canal type, 18.8%; the forward canal type, 4.1%; and the trifid canal type, 5.8%. Interestingly, seven cases of the trifid canal type, which has been rarely reported, were observed. The mean diameter of the bifid and trifid mandibular canals was 2.2 mm and that of the main mandibular canal was 4.3 mm. Their mean length was 16.9 mm; the mean superior angle was 149.2 degrees, and the mean inferior angle was 37.7 degrees. Bifid and trifid mandibular canals in the Korean population were observed at a relatively high rate through a CBCT evaluation, and the most common type was the retromolar canal. CBCT is suggested for a detailed evaluation of bifid and trifid mandibular canals before mandibular surgery.

  3. Using MUSIC to study relativistic nuclear collisions

    International Nuclear Information System (INIS)

    A large Multiple Sampling Ionization Chamber (MUSIC) has been developed as a part of the Heavy Ion Spectrometer System (HISS). This facility is being used for the study of relativistic nuclear collisions at the Bevalac of Lawrence Berkeley Laboratory. Preliminary data from MUSIC indicate that a charge resolution of one unit should be achieved from Z approximately equal to 7 to Z approximately equal to 100. (author)

  4. Detector instrumentation for nuclear fission studies

    Indian Academy of Sciences (India)

    Akhil Jhingan

    2015-09-01

    The study of heavy-ion-induced fusion–fission reactions require nuclear instrumentation that include particle detectors such as proportional counters, ionization chambers, silicon detectors, scintillation detectors, etc., and the front-end electronics for these detectors. Using the detectors mentioned above, experimental facilities have been developed for carrying out fusion–fission experiments. This paper reviews the development of detector instrumentation at IUAC.

  5. Progress report on nuclear spectroscopic studies

    International Nuclear Information System (INIS)

    The Nuclear Physics group at the University of Tennessee, Knoxville (UTK) is involved in several aspects of heavy-ion physics including both nuclear structure and reaction mechanisms. While the main emphasis is on experimental problems, the authors have maintained a strong collaboration with several theorists in order to best pursue the physics of their measurements. During the last year they have had several experiments at the ATLAS at Argonne National Laboratory, the GAMMASPHERE at the LBL 88 Cyclotron, and with the NORDBALL at the Niels Bohr Institute Tandem. Also, they continue to be very active in the WA93/98 collaboration studying ultra-relativistic heavy ion physics utilizing the SPS accelerator at CERN in Geneva, Switzerland and in the PHENIX Collaboration at the RHIC accelerator under construction at Brookhaven National Laboratory. During the last year their experimental work has been in three broad areas: (1) the structure of nuclei at high angular momentum, (2) the structure of nuclei far from stability, and (3) ultra-relativistic heavy-ion physics. The results of studies in these particular areas are described in this document. These studies concentrate on the structure of nuclear matter in extreme conditions of rotational motion, imbalance of neutrons and protons, or very high temperature and density. Another area of research is heavy-ion-induced transfer reactions, which utilize the transfer of nucleons to states with high angular momentum to learn about their structure and to understand the transfer of particles, energy, and angular momentum in collisions between heavy ions

  6. An investigation of the geochemistry and petrology of canal sediments

    OpenAIRE

    Dodd, Juliet S.

    2000-01-01

    Canals are artificial waterways, which are distinct from natural aquatic systems. As a result of their industrial heritage they have experienced high loadings of anthropogenic material, and consequently their sediments tend to have a bulk composition that is distinct from natural sediment. It is therefore expected that the geochemical behaviour of canal sediment may deviate significantly from that of natural sediment. This study investigates and contrasts the geochemistry and petrology of a r...

  7. Synchronous squamous and glandular neoplasia of the anal canal.

    OpenAIRE

    Yeong, M. L.; Wood, K. P.; Scott, B; Yun, K.

    1992-01-01

    A 48 year old man presented with invasive adenocarcinoma in the wall of a non-healing anal fistula. The subsequent abdomino-perineal resection specimen showed residual invasive carcinoma coexisting with in situ carcinoma of anal glands as well as in situ squamous carcinoma of the anal canal. The epithelium of the anal canal had koilocytotic features. DNA hybridisation studies by the dot blot technique showed weak positivity for human papillomavirus (HPV) subtypes 16, 18. This case illustrates...

  8. Canal network effects on the water balance in southeastern Srem

    OpenAIRE

    Gregorić Enike

    2009-01-01

    This paper presents the results of research and analyses of the effects of a drainage canal network on the water balance of southeastern Srem. The paper was derived from a doctoral thesis which contains a detailed study of key components of the water balance of southeastern Srem, including actual amounts of water removed via the drainage canal network. A linear multiple regression model was used to establish an analytical relationship between the amounts of evacuated water (a dependent variab...

  9. Electromagnetic studies of nucleon and nuclear structure

    International Nuclear Information System (INIS)

    Important objectives of the group are the study of subatomic structure through experimental measurements and the interpretation of the data through modeling. The common theme that unifies the studies of strong interactions and hadronic systems is the effort to determine the electromagnetic response as completely as possible. The general approach is coincidence detection of exclusive final states and determination of the dependence on the spin variables using polarized beams and targets and outgoing nucleon polarimetry. Direct reaction and giant resonance studies of electron quasi-elastic scattering on 12C and 16O are reported, as well as work on nuclear structure models and instrumentation development

  10. Dissolution studies of spent nuclear fuels

    International Nuclear Information System (INIS)

    To obtain quantitative data on the dissolution of high burnup spent nuclear fuel, dissolution study have been carried out at the Department of Chemistry, JAERI, from 1984 under the contract with STA entitled 'Reprocessing Test Study of High Burnup Fuel'. In this study PWR spent fuels of 8,400 to 36,100 MWd/t in averaged burnup were dissolved and the chemical composition and distribution of radioactive nuclides were measured for insoluble residue, cladding material (hull), off-gas and dissolved solution. With these analyses basic data concerning the dissolution and clarification process in the reprocessing plant were accumulated. (author)

  11. Studies of Nuclear Fuel by Means of Nuclear Spectroscopic Methods

    OpenAIRE

    Jansson, Peter

    2002-01-01

    The increasing demand for characterization of nuclear fuel, both from an operator and authority point of view, motivates the development of new experimental and, preferable, non-destructive methods. In this thesis, some methods based on nuclear spectroscopic techniques are presented. Various parameters of irradiated fuel are shown to be determined with high accuracy and confidence by utilizing gamma-ray scanning, tomography and passive neutron assay. Specifically, fuel parameters relevant for...

  12. A study on the nuclear foreign policy analysis

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Keun Bae; Choi, Y. M.; Lee, D. J.; Lee, K. S.; Lee, B. W.; Cho, I. H.; Ko, H. S.

    1996-12-01

    This study aims to analyses recent trends of international situation relating to nuclear non-proliferation and the adverse conditions in Korea`s pursuing self-support of such technology, so that it may map out effective strategies for the promotion of nuclear energy. This study analyses developments of international nuclear non-proliferation regime, which plays a main role in preventing the international proliferation of nuclear weapons. This study includes NPT, IAEA safeguards system, international export control regimes, CTBT, and NWFZs as the subjects of analysis. Second theme is international organizations concerning nuclear activities. This study mainly analyses IAEA activities which pursues the promotion of peaceful use of nuclear energy and nuclear non-proliferation simultaneously as a pivotal body of international nuclear cooperation. Third focus of this study is Northeast Asian circumstances pertaining to nuclear non-proliferation. The study looks into the DPRK nuclear issues, and reviews the developments of the proposed regional body for nuclear cooperation and the discussion on the Northeast Asian NWFZ. Fourth, but the most influential to Korean nuclear activities, is the U. S. nuclear policy, since U. S. takes the overwhelming initiative in the field of international nuclear non-proliferation. Therefore, this study gives much weight in analyzing the structure, procedures, recent trend, and pending issues of U. S. nuclear policy. (author). 78 refs., 5 tabs., 4 figs.

  13. A study on the nuclear foreign policy analysis

    International Nuclear Information System (INIS)

    This study aims to analyses recent trends of international situation relating to nuclear non-proliferation and the adverse conditions in Korea's pursuing self-support of such technology, so that it may map out effective strategies for the promotion of nuclear energy. This study analyses developments of international nuclear non-proliferation regime, which plays a main role in preventing the international proliferation of nuclear weapons. This study includes NPT, IAEA safeguards system, international export control regimes, CTBT, and NWFZs as the subjects of analysis. Second theme is international organizations concerning nuclear activities. This study mainly analyses IAEA activities which pursues the promotion of peaceful use of nuclear energy and nuclear non-proliferation simultaneously as a pivotal body of international nuclear cooperation. Third focus of this study is Northeast Asian circumstances pertaining to nuclear non-proliferation. The study looks into the DPRK nuclear issues, and reviews the developments of the proposed regional body for nuclear cooperation and the discussion on the Northeast Asian NWFZ. Fourth, but the most influential to Korean nuclear activities, is the U. S. nuclear policy, since U. S. takes the overwhelming initiative in the field of international nuclear non-proliferation. Therefore, this study gives much weight in analyzing the structure, procedures, recent trend, and pending issues of U. S. nuclear policy. (author). 78 refs., 5 tabs., 4 figs

  14. 两种根管充填剂疼痛反应临床观察%Clinical Study of Pain Reaction to Two Kinds of Root Canal Filler

    Institute of Scientific and Technical Information of China (English)

    魏达

    2012-01-01

    目的:比较Cortisomol根充糊剂和氧化锌丁香油根管充填剂进行根管充填术后疼痛反应发病率的情况.方法:对198颗惠牙分别使用Cortisomol根充糊剂和氧化锌根管充填剂进行根管充填,观察其术后反应情况.结果:Cortisomol根充糊剂组术后疼痛反应的发病率显著低于氧化锌根管充填剂组(P<0.01).结论:使用Cortisomol根充糊剂是一种比较理想的根管充填剂,可以减少病人痛苦.%Objective: To compare the incidence of pain reaction after root canal filling operation by filling Cortisomol Paste and Zinc Clove Oil Paste. Method: Use Cortisomol Paste and Zinc Clove Oil Paste to do the root canal filling operation on 198 sick teeth, respectively.Result: The incidence of pain reaction after root canal filling operation by filling Cortisomol Paste was obviously lower than the Zinc Clove Oil Paste ( P<0.01 ) . Conclusion : Relatively speaking,Cortisomol Paste is an ideal root canal filling paste since dentists can alleviate the sufferings of the patients by using it.

  15. Spinal canal narrowing during simulated frontal impact

    OpenAIRE

    Ivancic, Paul C.; Panjabi, Manohar M.; Tominaga, Yasuhiro; Pearson, Adam M.; Elena Gimenez, S.; Maak, Travis G.

    2005-01-01

    Between 23 and 70% of occupants involved in frontal impacts sustain cervical spine injuries, many with neurological involvement. It has been hypothesized that cervical spinal cord compression and injury may explain the variable neurological profile described by frontal impact victims. The goals of the present study, using a biofidelic whole cervical spine model with muscle force replication, were to quantify canal pinch diameter (CPD) narrowing during frontal impact and to evaluate the potent...

  16. Root canal filling using Resilon: a review.

    LENUS (Irish Health Repository)

    Shanahan, D J

    2011-07-01

    Root canal treatment is achieved by chemo-mechanical debridement of the root canal system followed by filling. The filling material \\'entombs\\' residual bacteria and acts as a barrier which prevents the entrance of oral microorganisms and reinfection of the root canal system through microleakage. However, filling with contemporary root filling materials such as gutta-percha offers limited long-term resistance to microorganisms; as a result other materials such as Resilon have been investigated as alternatives. The aim of this review was to analyse the literature to consider whether Resilon is a suitable root canal filling material. A MEDLINE and Cochrane library search including various keyword searches identified several papers which investigated or discussed Resilon or RealSeal\\/Epiphany. Analysis of the literature demonstrated that the bulk of the literature is in vitro in nature, based largely on leakage-type studies, and demonstrates a wide variety of methodologies with conflicting findings; as a result meaningful conclusions are difficult. Within the limit of these in vitro studies Resilon appears to perform adequately in comparison to gutta-percha, however, as a result of the questionable merit of such studies, it cannot presently be considered an evidence-based alternative to the current gold standard gutta-percha. It is imperative that before Resilon is considered as a replacement material, a better understanding of the physical properties of the resin sealer and the reality of the adhesive \\'monoblock\\' are elucidated. The literature also demonstrates a paucity of quality long-term clinical outcome studies which will need to be addressed before firm conclusions can be reached.

  17. Future of Nuclear Structure Studies. Proceedings of a Panel on the Future of Nuclear Structure Studies

    International Nuclear Information System (INIS)

    As the world enters an age in which nuclear electric power is a reality and man increasingly benefits from nuclear applications in medicine, agriculture and industry, it is useful to re-examine the basic sciences that underlie these important developments. In many ways modern nuclear technology is built on, or derived from, basic research on the atomic nucleus. Today, nuclear physics studies are a fundamental part of the national atomic energy programs in many of the Member States, now more than 100, of the International Atomic Energy Agency. The purpose of the IAEA Panel on the Future of Nuclear Structure Studies, held at Dubna on 1-3 July 1968, was to provide an appraisal of the present status of our knowledge of nuclear structure, to point out the open problems, and to suggest the most promising directions for future research. To reflect the needs of many of the IAEA member nations, special consideration was given to the problems of smaller institutes and developing countries. The major recommendation of the panel concerned the question of regional centres for low- and medium-energy nuclear physics research. The panel supported the organization of regional centres formed by three or more developing countries and equipped with apparatus of intermediate cost and sophistication. The text of the resolution appears at the end of this book, which contains the papers presented to the panel and a record of the discussions. The panel was held in conjunction with the Dubna-sponsored International Symposium on Nuclear Structure, which took place immediately after the panel, on 4-11 July 1968. The invited papers from this symposium, all in English, were published by the Agency in 1968 under the title ''Nuclear Structure: Dubna Symposium 1968''

  18. Seepage from canals having variable shape and partial lining

    Science.gov (United States)

    Mirnateghi, A.; Bruch, J. C.

    1983-07-01

    The numerical models presented here are solutions to the steady two-dimensional flow through a porous medium from canals of variable shape with partial lining. Two main cases are studied. The first case is the seepage flow from canals with impervious lining on their sloping sides. The second case is for seepage from canals in which the impervious lining is located on the base of the canal and the sides are unlined. The Baiocchi transformation and method is used to develop a boundary value problem which is then solved by the finite-difference successive over-relaxation method with projection. A sample problem of each case is presented. The discharge rates and free surfaces of the seepage flows are obtained through the numerical scheme, and are compared with available analytical results.

  19. Atypical situations in root canals anatomy of human mandibular premolars

    Directory of Open Access Journals (Sweden)

    Fabrício SCAINI

    2005-05-01

    Full Text Available The knowledge of the teeth internal anatomy that will receive endodontic treatment is very important for the success of the treatment and prognosis of those teeth. In this study, the morphological variations that may occur in relation to the number of root canals present in the premolar mandibular teeth group were discussed, as well as the most efficient methods to diagnose the existence of these variations, in order to have a clearer diagnosis of the number of root canals to be treated.A case of an endodontic treatment of a mandibular premolar with 4 root canals was reported and some cases of endodontic treatment in mandibular premolars with 1, 2 and 3 root canals were shown.

  20. Pollution of Lahore canal water in the city premises

    International Nuclear Information System (INIS)

    Water contamination is one of the major environmental pollution problems facing Pakistan because it has a direct impact on the health of human beings and crops. Lahore Canal water is being used both for irrigation and a source of ground water recharge. For the best use of this water, extent of pollution and its effect on soil hydraulic properties needs to be studied. For this purpose, water samples from twenty three sites and soil samples from three sites were collected along the Canal within the city limits of Lahore. The survey of the area from Jallo Park to Mall Road, show that all the abadies/colonies and industries situated on both sides of the canal dump their waste water and garbage in to canal. This result in increase of salinity as well as BOD and COD values which were found maximum at the locations of Herbuns Pura, Mughal Pura Dharam Pura, and Thoker Niaz Baig. (authors)

  1. Optimal volume of local anaesthetic for the adductor canal block

    DEFF Research Database (Denmark)

    Jæger, P.; Jenstrup, M. T.; Lund, J.;

    2015-01-01

    Background: Theoretically, the ideal volume of local anaesthetic for adductor canal block (ACB) would ensure sufficient filling ofthe canal and avoid proximal spread to the femoral triangle. In this dose-finding study, we aimed to investigate the minimaleffective volume for an ACB needed to fill...... the adductor canal distally in at least 95% of patients (ED95). Methods: We performed a blinded trial, enrolling 40 healthy men. All subjects received an ACB with lidocaine 1%. Volumes wereassigned sequentially to the subjects using the continual reassessment method followed by Bayesian analysis to...... baseline) and sensory block. Results: The ED95 was 20 ml, with an estimated probability of sufficiently filling the canal of 95.1% (95% credibility interval: 0.91–0.98). Proximal spread to the femoral triangle was seen in 0/4 (0%), 7/12 (58%), 4/8 (50%), and 8/16 (50%) subjects with the 5, 10, 15,and 20 ml...

  2. Underground nuclear astrophysics studies with CASPAR

    Science.gov (United States)

    Robertson, Daniel; Couder, Manoel; Greife, Uwe; Strieder, Frank; Wiescher, Michael

    2016-02-01

    The drive of low-energy nuclear astrophysics laboratories is to study the reactions of importance to stellar burning processes and elemental production through stellar nucleosynthesis, over the energy range of astrophysical interest. As laboratory measurements approach the stellar burning window, the rapid drop off of cross-sections is a significant barrier and drives the need to lower background interference. The natural background suppression of underground accelerator facilities enables the extension of current experimental data to lower energies. An example of such reactions of interest are those thought to be sources of neutrons for the s-process, the major production mechanism for elements above the iron peak. The reactions 13C(α,n)16O and 22Ne(α,n)25Mg are the proposed initial focus of the new nuclear astrophysics accelerator laboratory (CASPAR) currently under construction at the Sanford Underground Research Facility, Lead, South Dakota

  3. 红旗渠题材的文学价值%The Study on the Literary Values of the Themes of Red Flag Canal

    Institute of Scientific and Technical Information of China (English)

    王彦永

    2015-01-01

    半个世纪以来,红旗渠以其巨大的精神价值产生着越来越大的社会影响,文学创作活动始终伴随着红旗渠的建设过程,创作实践亦在随后的岁月里愈加丰富,内容和形式随着时代的变迁不断发生着变化。深入认识并持续挖掘红旗渠题材的文学价值,把握这一题材创作的变化规律,可以丰富人们对红旗渠精神的认识,并对今后一个时期繁荣该领域的文学创作发挥一定的借鉴作用。%over the past 50 years, the great spiritual values of Red Flag Canal have increasingly produced great social influence. The construction process of the Red Flag Canal is followed by the activities of literary creation based on the theme of Red Flag Canal. Such literary creation is becoming increasingly rich with the years passing by. The content and form of the literary creation with this theme are constantly changing with the ages changing. The in-depth understanding and continuous digging of the literary value of the Red Flag Canal, and grasping the rules of variation of this literary subject, can enrich people's knowledge of the Red Flag Canal spirit, which will play a role as a reference for the future prosperity of the literary creation based on this theme.

  4. Prominent central spinal canal on MRI - normal variant or pathology

    International Nuclear Information System (INIS)

    Full text: The sensitivity of MRI can make differentiation of normal from abnormal challenging.The study investigates whether a visible central spinal canal is pathological or a normal variant. We review eight MRI (mostly on a 1.5 Tesla unit) cases where there is a visible central cavity in keeping with a central canal and review the literature. The central canal is a space in the medial part of the grey-matter commissure between the anterior and posterior horns. Histopathological studies show that the canal is present at birth with the majority showing subsequent involution but is uncommonly imaged on MRI. The main differential diagnosis is syringomyelia which usually presents with deficits in pain and sensation corresponding to the appropriate level often with a demonstrable aetiology. Two thirds of our patients were female with an average age of thirty-six years (range 26-45). The patients were largely asymptomatic or their symptoms appeared unrelated to the imaging findings. Three patients had minor previous trauma and two others had non-bacterial meningitis up to twenty years earlier. No patient had known spinal surgery or trauma.The cavity corresponded tomographically to the expected site of the central canal. The canal was in the thoracic location. The canal diameter ranged from one to five millimetres and its length varied from one half a vertebral body height to extending over the entire thoracic region. Its configuration was either filiform or fusiform, with smooth contours. No predisposing features to suggest syringomyelia or other structural abnormalities were noted. Where Gadolinium was given no abnormal enhancement was observed. These cases add to the literature and suggest that these prominent canals are largely asymptomatic and should be viewed as normal variants. Copyright (2002) Blackwell Science Pty Ltd

  5. Inclination of the infraorbital canal studied on dry skulls expresses the maxillary growth pattern: a new contribution to the understanding of change in inclination of ectopic canines during puberty

    DEFF Research Database (Denmark)

    Caspersen, Louise M; Christensen, Ib J; Kjær, Inger

    2009-01-01

    anomalies. Frontal radiographs were taken of each skull placed in the Frankfort horizontal plane, with a radiopaque marker in the infraorbital canal. The maxillary transversal growth pattern was expressed as the infraorbital transversal angle (IOt) formed between a line through the contour of the bilateral...... analysis. Results. The direction of the infraorbital canal (66.08 degrees , 95% CI: 62.53-69.64) depended on the transversal growth: an increased PW of 1 mm resulted in a decreased IOt of 1.84 degrees (p=0.041); an increase in IO of 1 mm resulted in an increased IOt of 2.24 degrees (p=0.017); and an...... increased AP of 1 mm resulted in a decreased IOt of 3.30 degrees (p=0.066). Conclusions. The study indicates that the direction of the infraorbital canal in frontal view reflects the transversal growth of the maxilla. A wide maxilla posteriorly resulted in a small infraorbital transversal angle. These...

  6. Pollution of the Begej Canal sediment--metals, radioactivity and toxicity assessment.

    Science.gov (United States)

    Dalmacija, B; Prica, M; Ivancev-Tumbas, I; van der Kooij, A; Roncevic, S; Krcmar, D; Bikit, I; Teodorovic, I

    2006-07-01

    The Begej Canal is one among a large number of canals in Vojvodina (Northern Province of Serbia and Montenegro). The paper describes a study of metal and radioactivity contamination of the Begej Canal sediment. It is also concerned with the evaluation of sediment acute toxicity based on standard test species Daphnia magna and simultaneously extracted metals and acid volatile sulfides. The quality of sediment was assessed according to Dutch standards, but the results were also compared with some Canadian and USEPA (United States Environmental Protection Agency) guidelines for sediment quality. The results showed severe pollution with chromium, copper, cadmium and zinc, whereby the anthropogenic origin of these contaminants was indicated. The tests of toxicity of sediment pore water to D. magna, gave no indication of the presence of substances in acutely toxic concentrations to this species. It can be speculated that, despite of high metal contents, the observed toxicity was low because of the high contents of clay and iron, as well as sulphide. Also, based on a comparison with the Danube sediment and Vojvodina soil in general, the data of the Begej sediment contamination with 238U and 137Cs. The 137Cs data were used for approximate dating of the sediment. No traces of contamination by nuclear power plants in the region were found, while the presence of technologically enhanced naturally occurring radioactive materials (TENORM) was proved. Conclusions based on different criteria for sediment quality assessment were in some cases contradictory. Study also showed that radioactivity aspects can be useful in sediment quality surveys. The obtained results will be invaluable for the future activities regarding integrated water management based on EC Water Framework Directive (2000/60/EC) in the Danube basin, and particularly in the region of crossborder water body of the Begej Canal. PMID:16527352

  7. Study of nuclear data online services

    International Nuclear Information System (INIS)

    A web-based nuclear data service software system, NDOS ( Nuclear Data Online Services), has been developed and released in Sep. 2001. Through the Internet, this system distributes charge of free 8 international nuclear databases: 5 evaluated neutron databases (BROND, CENDL, ENDF, JEF and, JENDL), Evaluated Nuclear Structure and Decay File ENSDF, Experimental Nuclear Data Library EXFOR database and IAEA Photonuclear Data Library. A software package, NDVS (Nuclear Data Viewing System), facilitates the visualization and manipulation of nuclear data. The computer programs providing support for database management and data retrievals are based on the Linux implementation of PHP and the MySQL software. (authors)

  8. Cleaning ability of chlorhexidine gel and sodium hypochlorite associated or not with EDTA as root canal irrigants: a scanning electron microscopy study

    Directory of Open Access Journals (Sweden)

    Bruno Carvalho de Vasconcelos

    2007-10-01

    Full Text Available The aim of this study was to evaluate the cleaning efficacy of 2% chlorhexidine gluconate gel (CHX compared to 2.5% sodium hypochlorite solution (NaOCl associated or not with 17% EDTA used as irrigants during the biomechanical preparation. Fifty freshly extracted single-rooted human teeth with complete apex formation were randomly divided into five groups: G1 - sterile saline, G2 - 2.5% NaOCl, G3 - 2% CHX, G4 - 2.5% NaOCl + EDTA and G5 - 2% CHX + EDTA. The specimens of G1 were subdivided into two control groups. The teeth were decoronated and the coronal and middle root thirds were prepared with Gates-Glidden burs, and the apical third was reserved to manual instrumentation. All procedures were performed by a single operator. In all groups, 2 mL of irrigant was delivered between each file change. The teeth were sectioned and prepared for analyses under scanning electron microscopy (SEM. SEM micrographs were graded according to a score scale by two examiners. Data were analyzed statistically by Kruskal-Wallis and Dunn tests at 1% significance level. The best results were obtained in the groups in which the irrigant was used followed by the chelating agent. No statistically significant difference was observed among G4, G5 and the positive control group (p<0.01. The groups G2 and G3 were significantly different from the others, presenting the worst cleaning capacity. In conclusion, the use of the chelating agent is necessary to obtain clean canal walls, with open tubules and no heavy debris. The use of 2% chlorhexidine gluconate gel alone is not able to remove the smear layer.

  9. Studies in Low-Energy Nuclear Science

    International Nuclear Information System (INIS)

    This report presents a summary of research projects in the area of low energy nuclear reactions and structure, carried out between 1 January 2003 and 31 December 2005 and supported by U.S. DOE grant number DE-FG03-03NA00074. Cross sections measured with high resolution have been subjected to an Ericson theory analysis to infer information about the nuclear level density. Other measurements were made of the spectral shape of particles produced in evaporation processes; these also yield level density information. A major project was the development of a new Hauser-Feshbach code for analyzing such spectra. Other measurements produced information on the spectra of gamma rays emitted in reactions on heavy nuclei and gave a means of refining our understanding of gamma-ray strength functions. Finally,reactions on light nuclei were studied and subjected to an R-matrix analysis. Cross sections fora network of nuclear reactions proceedingthrough a given compound nucleus shouldgreatly constrain the family of allowed parameters. Modifications to the formalism andcomputer code are also discussed.

  10. Studies in Low-Energy Nuclear Science

    Energy Technology Data Exchange (ETDEWEB)

    Brune, Carl R; Grimes, Steven M

    2006-03-30

    This report presents a summary of research projects in the area of low energy nuclear reactions and structure, carried out between 1 January 2003 and 31 December 2005 and supported by U.S. DOE grant number DE-FG03-03NA00074. Cross sections measured with high resolution have been subjected to an Ericson theory analysis to infer information about the nuclear level density. Other measurements were made of the spectral shape of particles produced in evaporation processes; these also yield level density information. A major project was the development of a new Hauser-Feshbach code for analyzing such spectra. Other measurements produced information on the spectra of gamma rays emitted in reactions on heavy nuclei and gave a means of refining our understanding of gamma-ray strength functions. Finally,reactions on light nuclei were studied and subjected to an R-matrix analysis. Cross sections fora network of nuclear reactions proceedingthrough a given compound nucleus shouldgreatly constrain the family of allowed parameters. Modifications to the formalism andcomputer code are also discussed.

  11. Perspectives in nuclear medicine: pulmonary studies

    International Nuclear Information System (INIS)

    Since the introduction of I-131 labeled macroaggregates in 1964, noninvasive techniques involving injection of radiolabeled agents and remote detection of emitted radiation have become well established in detecting pulmonary disorders in routine clinical medicine. In the past, pulmonary nuclear medicine has been dominated by studies that depict the distribution of pulmonary perfusion and/or ventilation-perfusion balance (e.g., for the detection of pulmonary embolism, obstructive airway disease, lung carcinoma). With the recent development of emission tomography and the potential for new, function-oriented radiopharmaceuticals, however, pulmonary nuclear medicine is entering a new era. The status of contemporary pulmonary nuclear medicine is briefly reviewed in several areas of major interest and applications and focus on areas where new developments are needed and seem feasible in the near future. Several important regional physiological processes measurable by these techniques include: (a) the presence or absence of pulmonary embolism, (b) relative pulmonary blood flow, (c) permeability to specific molecules, (d) lung tissue metabolism, (e) ventilation distribution and (f) the relationship between ventilation and blood flow (perfusion)

  12. Studies in Low-Energy Nuclear Science

    International Nuclear Information System (INIS)

    This report presents a summary of research projects in the area of low energy nuclear reactions and structure, carried out between March 1, 2006 and October 31, 2009 which were supported by U.S. DOE grant number DE-FG52-06NA26187. We describe here research into low-energy nuclear reactions and structure. The statistical properties of nuclei have been studied by measuring level densities and also calculating them theoretically. Our approach of measuring level densities via evaporation spectra is able to reach a very wide range of nuclei by using heavy ion beams (we expect to develop experiments using radioactive beams in the near future). Another focus of the program has been on γ-ray strength functions. These clearly impact nuclear reactions, but they are much less understood than corresponding transmission coefficients for nucleons. We have begun investigations of a new approach, using γ-γ coincidences following radiative capture. Finally, we have undertaken several measurements of cross sections involving light nuclei which are important in various applications. The 9Be(α,n) and B(d,n) reactions have been measured at Ohio University, while neutron-induced reactions have been measured at Los Alamos (LANSCE).

  13. Chlorhexidine as a root canal irrigant: Antimicrobial and scanning electron microscopic evaluation

    OpenAIRE

    Živković Slavoljub; Pavlović Violeta

    2010-01-01

    Introduction. Selection of irrigant is very important for longterm success of root canal therapy. Objective. This study was undertaken to evaluate the antimicrobial effects of 2% chlorhexidine digluconate solution (CHX) against five selected microorganisms and to evaluate its efficacy in root canal cleaning. Methods. In this study, by agar diffusion test, were evaluated antimicrobial effects of three root canal irrigants: 5.25% NaOCl, 2.5% NaOCl and 2% CHX. The microorganisms tested in ...

  14. The Effect of Three Irrigants on the Coronal Leakage of the Root Canals System Irrigants

    OpenAIRE

    Zare Jahromi, Maryam; Barekatain, Mehrdad; Ebrahimi, Maziar; Askari, Bahare

    2010-01-01

    INTRODUCTION The production of smear layer during canal instrumentation is thought to increase coronal microleakage even after canal obturation. Previous studies have shown that the type of irrigant does not necessarily affect the seal of the obturation. Our study aimed to evaluate the effect of three irrigation solutions (MTAD, citric acid and EDTA/NaOCl) on the coronal microleakage of root canals. MATERIALS AND METHODS Fifty five intact single rooted teeth were instrumented and randomly div...

  15. Effect of postmilking teat antisepsis on teat canal infections in lactating dairy cows.

    Science.gov (United States)

    Nickerson, S C; Watts, J L; Boddie, R L; Ray, C H

    1990-02-01

    Effects of a .18% iodophor teat dip and a fatty acid plus lactic acid teat dip on teat canal infections were studied in two separate trials under experimental challenge procedures using Staphylococcus aureus and Streptococcus agalactiae. The iodophor teat dip was 90% effective in preventing new S. aureus teat canal infections and 95.6% effective in reducing progression of S. aureus teat canal infections to intramammary infections. The dip also reduced persistence of S. aureus teat canal colonizations from week to week by 94.4%. The fatty acid plus lactic acid dip had no effect on preventing S. aureus teat canal infections but reduced progression of S. aureus teat canal infections to intramammary infections by 43.8%. The fatty acid plus lactic acid dip also reduced the persistence of S. aureus teat canal infections by 39%. An insufficient number of Strep. agalactiae teat canal infections was detected in both trials for valid analyses. Neither dip had any effect on prevalence of naturally occurring, coagulase-negative staphylococcal teat canal infections or on teat canal infections by other organisms. PMID:2184176

  16. Deadbands and the Dynamic Response and Performance of Large Water Transfer Canal System

    Institute of Scientific and Technical Information of China (English)

    DING Zhiliang; WANG Changde; TAN Guangming; GUAN Guanghua

    2009-01-01

    An operating simulation mode for multireach canal system in series under gate regulating is established. The discharge feedforward plus water lever feedback PID controller was adopted. And the performance indicators are introduced to evaluate the control effects of canal operation. Influence on dynamic response process and dynamic performance as well as the control actions of canal system are studied according to the variation of the gate deadband and water level deadband. The results showed that the larger the gate deadband, the worse, the control effect of canal system over water level, and so done the stable process of gate discharge, yet the stable process of gate opening was getting better, while the upstream gate regulation of each canal pool was less at the time when canal stabilizes;the closer to downstream end of canal, the lager steady-state error of this canal pool was, and the lager influence of gate deadband on the steady-state error as well as response time of this canal pool was;the canal system can not acquire superiority in both the control performance and control actions when only the water level deadband was established.

  17. El Canal del Atazar I

    Directory of Open Access Journals (Sweden)

    López de Berges y de los Santos, Emilio

    1967-03-01

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

  18. Long-term cytotoxic effects of contemporary root canal sealers

    Directory of Open Access Journals (Sweden)

    Emmanuel Joao Nogueira Leal da SILVA

    2013-03-01

    Full Text Available Objectives The aim of the present study was to investigate the effects of root canal sealers on the cytotoxicity of 3T3 fibroblasts during a period of 5 weeks. Material and Methods Fibroblasts (3T3, 1×105 cells per well were incubated with elutes of fresh specimens from eight root canal sealers (AH Plus, Epiphany, Endomethasone N, EndoREZ, MTA Fillapex, Pulp Canal Sealer EWT, RoekoSeal and Sealapex and with elutes of the same specimens for 5 succeeding weeks after immersing in simulated body fluid. The cytotoxicity of all root canal sealers was determined using the MTT assay. Data were analyzed using ANOVA and Tukey's test. Results RoekoSeal was the only sealer that did not show any cytotoxic effects (p<0.05. All the other tested sealers exhibited severe toxicity initially (week 0. MTA Fillapex remained moderately cytotoxic after the end of experimental period. Toxicity of the other tested sealers decreased gradually over time. The evaluated root canal sealers presented varying degrees of cytotoxicity, mainly in fresh mode. Conclusions RoekoSeal had no cytotoxic effect both freshly mixed and in the other tested time points. MTA Fillapex was associated with significantly less cell viability when compared to the other tested root canal sealers.

  19. [Solid liver mass. Studies with nuclear medicine].

    Science.gov (United States)

    Domínguez Gadea, L; Fernández Salazar, L; García Grávalos, R; Rodríguez Eyré, J L

    2000-04-01

    We present the case of a 23 year old female with two incidentally detected hepatic mass that have not clinically o radiologically specific findings. Nuclear medicine tracers, including colloids and hepatobiliary agents showing the characteristic findings of focal nodular hyperplasia: Hypervascularization, normal uptake of colloids, accumulation of hepatobiliary tracer and hot spots due to the retention of this tracer during the clearance fhase. The patient was underwent hepatectomy. The examination of surgical specimen revealed focal nodular hyperplasia. The scintigraphic studies could be an useful tool in the noninvasive diagnosis of liver masses. PMID:10893773

  20. Study of Iodine Prophylaxis Following Nuclear Accidents

    International Nuclear Information System (INIS)

    Study of iodine prophylaxis following nuclear accidents has been done. Giving stable iodine to a population exposed by I-131 is one of preventive action from internal radiation to the thyroid gland. Stable iodine could be given as Kl tablet in a range of dose of 30 mg/day to 130 mg/day. Improper giving of stable iodine could cause side effect to health, so then some factors should be considered i. e. dose estimation, age, dose of stable iodine to be given, duration of stable iodine prophylaxis and risk of health. (author)

  1. Nuclear-Powered GPS Spacecraft Design Study

    Energy Technology Data Exchange (ETDEWEB)

    Raab, Bernard

    1977-05-01

    This is the final report of a study to investigate the potential benefits of a nuclear (radioisotope) - powered satellite for advanced phases of the Global Positioning System (GPS) program. The critical parameters were: power to user; mean mission duration; orbital predictability; thermal control of on-board frequency standards; and vulnerability. The reference design approach is described, and input data are given for two power systems that are under development: an organic Rankine system and a Brayton cycle system. Reference design details are provided and structural design and analysis are discussed, as well as thermal design and analysis. A higher altitude version is also considered.

  2. Shell model studies for nuclear astrophysics

    International Nuclear Information System (INIS)

    Shell model studies have contributed in recent years significantly to improve nuclear input required in simulations of the dynamics of astrophysical objects and their associated nucleosynthesis. This manuscript highlights a few examples like electron capture rates of importance for the evolution of core-collapse supernovae and the nucleosynthesis in thermonuclear supernovae, neutrino-nucleus cross sections with relevance to the supernova neutrino spectra and finally half lives of neutron-rich nuclei with magic neutron numbers which serve as waiting points in the mass flow of the astrophysical r-process

  3. Isomeric target for nuclear structure studies

    CERN Document Server

    Maunoury, L; Aubert, P; Aupiais, J; Baudin, M; Blier, G; Bonnereau, B; Boulin, Y; Pointurier, F; Sauvestre, J E; Sigaud, J; Szmigiel, M

    2002-01-01

    The experimental studies on nuclear structure and reactions dealing with nuclei in their isomeric state are, actually, mainly constrained by the difficulty of producing isomeric targets. The CEA/Bruyeres-le-Chatel laboratory has initiated the production of a sup 1 sup 7 sup 7 Lu sup m isomeric target. We plan to reach a 45% isomeric purity associated with a number of isomeric nuclei about 10 sup 1 sup 5. This target will be available for experiments at the end of the year 2000. The method performed to produce such targets will be discussed.

  4. Shaping ability of NT Engine and McXim rotary nickel-titanium instruments in simulated root canals. Part 2.

    Science.gov (United States)

    Thompson, S A; Dummer, P M

    1997-07-01

    The aim of this laboratory-based study was to determine the shaping ability of NT Engine and McXim nickel-titanium rotary instruments in simulated root canals. A total of 40 canals with four different shapes in terms of angle and position of curve were prepared with NT Engine and McXim instruments, using the technique recommended by the manufacturer. Part 2 of this report describes the efficacy of the instruments in terms of prevalence of canal aberrations, the amount and direction of canal transportation and overall postoperative shape. Pre- and postoperative images of the canals were taken using a video camera attached to a computer with image analysis software. The pre- and postoperative views were superimposed to highlight the amount and position of material removed during preparation. No zips, elbows, perforations or danger zones were created during preparation. Forty-two per cent of canals had ledges on the outer aspect of the curve, the majority of which (16 out of 17) occurred in canals with short acute curves. There were significant differences (P canal shapes in terms of the incidence of ledges. There were highly significant differences (P canal shapes in total canal width at specific points along the canal length and in the amount or resin removed from the inner and outer aspects of the curve. The direction of canal transportation at the end-point of preparation was most frequently towards the outer aspect of the curve, especially in canals with 40 degrees curves. At the beginning of the curve, transportation in the majority of canals was towards the inner aspect of the curve. Mean absolute transportation was less than 0.03 mm throughout the curve and towards the end-point, with significant differences between canal shapes occurring at the apex (P canals was good. PMID:9477813

  5. A quantitative analysis of rotary, ultrasonic and manual techniques to treat proximally flattened root canals

    Directory of Open Access Journals (Sweden)

    Fabiana Soares Grecca

    2007-04-01

    Full Text Available OBJECTIVE: The efficiency of rotary, manual and ultrasonic root canal instrumentation techniques was investigated in proximally flattened root canals. MATERIAL AND METHODS: Forty human mandibular left and right central incisors, lateral incisors and premolars were used. The pulp tissue was removed and the root canals were filled with red die. Teeth were instrumented using three techniques: (i K3 and ProTaper rotary systems; (ii ultrasonic crown-down technique; and (iii progressive manual technique. Roots were bisected longitudinally in a buccolingual direction. The instrumented canal walls were digitally captured and the images obtained were analyzed using the Sigma Scan software. Canal walls were evaluated for total canal wall area versus non-instrumented area on which dye remained. RESULTS: No statistically significant difference was found between the instrumentation techniques studied (p<0.05. CONCLUSION: The findings of this study showed that no instrumentation technique was 100% efficient to remove the dye.

  6. A Study on Research Trend in Nuclear Forensics

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyungmin; Yim, Hobin; Lee, Seungmin; Hong, Yunjeong; Kim, Jae Kwang [Korea Institute of Nuclear Nonproliferation and Control, Daejeon (Korea, Republic of)

    2014-05-15

    The international community has recognized the serious threat posed by nuclear and other radioactive material out of regulatory control. To address these concerns, the Office of Nuclear Security of the international Atomic Energy Agency (IAEA) is developing, inter alia, guidance for nuclear forensics to assist Member States. According to the IAEA Incident and Trafficking Database (ITDB) of the IAEA to record the illegal trade and trafficking incidents of nuclear material or other radioactive material, incidents of 2331 have been reported in 1993 to 2012. These incidents mean that we are not safe for nuclear material. In order to solve the case generated by the illicit trafficking of nuclear material and the efficient management of nuclear material, the study of nuclear forensics is very important. In this study, we investigated the analytical techniques and the current status of nuclear forensics research. In this study, we investigated the current status of research of nuclear forensics, procedures for analysis and nuclear forensics analysis technique. A result of the study, we have been found that the major institutes and laboratory actively research on analysis technique and nuclear forensics. However, research on nuclear forensics is still in early stage, ROK is necessary preliminary survey of analysis technique and foundation of physical, chemical, and morphology characteristics of nuclear materials.

  7. A Study on Research Trend in Nuclear Forensics

    International Nuclear Information System (INIS)

    The international community has recognized the serious threat posed by nuclear and other radioactive material out of regulatory control. To address these concerns, the Office of Nuclear Security of the international Atomic Energy Agency (IAEA) is developing, inter alia, guidance for nuclear forensics to assist Member States. According to the IAEA Incident and Trafficking Database (ITDB) of the IAEA to record the illegal trade and trafficking incidents of nuclear material or other radioactive material, incidents of 2331 have been reported in 1993 to 2012. These incidents mean that we are not safe for nuclear material. In order to solve the case generated by the illicit trafficking of nuclear material and the efficient management of nuclear material, the study of nuclear forensics is very important. In this study, we investigated the analytical techniques and the current status of nuclear forensics research. In this study, we investigated the current status of research of nuclear forensics, procedures for analysis and nuclear forensics analysis technique. A result of the study, we have been found that the major institutes and laboratory actively research on analysis technique and nuclear forensics. However, research on nuclear forensics is still in early stage, ROK is necessary preliminary survey of analysis technique and foundation of physical, chemical, and morphology characteristics of nuclear materials

  8. An alternative magnesium-based root canal disinfectant:Preliminary study of its efficacy against Enterococcus faecalis and Candida albicans in vitro

    Institute of Scientific and Technical Information of China (English)

    Lin Zhu; Peng Wan; Jiaohong Duan; Lili Tan; Ke Yang

    2014-01-01

    Organisms invading root canal systems result in serious pulpal and periapical disease. To eliminate microorganisms and restrain secondary infections, dental materials with antibacterial properties are urgently needed in endodontics. Magnesium is considered as a promising biodegradable and biocompatible implant material. However, there are barely researches about its application in endodontic therapy. This work investigated the in vitro efficacy of magnesium powder against Enterococcus faecalis and Candida albicans compared with a common disinfectant, calcium hydroxide. With Calcium hydroxide served as a comparison it demonstrated the qualified antibacterial and anti-fungus properties of Mg as root canal disinfectant due to its high alkalinity of degradation, and the antimicrobial efficacy enhanced with the decreasing powder size.

  9. Advanced nuclear systems. Review study; Fortgeschrittene Nuklearsysteme. Review Study

    Energy Technology Data Exchange (ETDEWEB)

    Liebert, Wolfgang; Glaser, Alexander; Pistner, Christoph [Interdisziplinaere Arbeitsgruppe Naturwissenschaft, Technik und Sicherheit (IANUS), Darmstadt University of Technology, Hochschulstrasse 10, D-64289 Darmstadt (Germany); Baehr, Roland; Hahn, Lothar [Institute for applied ecology (Oeko-Institut), Elisabethenstrasse 55-57, D-64283 Darmstadt (Germany)

    1999-04-01

    The task of this review study is to from provide an overview of the developments in the field of the various advanced nuclear systems, and to create the basis for more comprehensive studies of technology assessment. In an overview the concepts for advanced nuclear systems pursued worldwide are subdivided into eight subgroups. A coarse examination raster (set pattern) is developed to enable a detailed examination of the selected systems. In addition to a focus on enhanced safety features, further aspects are also taken into consideration, like the lowering of the proliferation risk, the enhancement of the economic competitiveness of the facilities and new usage possibilities (for instance concerning the relaxation of the waste disposal problem or the usage of alternative fuels to uranium). The question about the expected time span for realization and the discussion about the obstacles on the way to a commercially usable reactor also play a substantial role as well as disposal requirements as far as they can be presently recognized. In the central chapter of this study, the documentation of the representatively selected concepts is evaluated as well as existing technology assessment studies and expert opinions. In a few cases where this appears to be necessary, according technical literature, further policy advisory reports, expert statements as well as other relevant sources are taken into account. Contradictions, different assessments and dissents in the literature as well as a few unsettled questions are thus indicated. The potential of advanced nuclear systems with respect to economical and societal as well as environmental objectives cannot exclusively be measured by the corresponding intrinsic or in comparison remarkable technical improvements. The acceptability of novel or improved systems in nuclear technology will have to be judged by their convincing solutions for the crucial questions of safety, nuclear waste and risk of proliferation of nuclear weapons

  10. Energy policy study. Volume 10. Nuclear power regulation

    International Nuclear Information System (INIS)

    This report examines the programs for regulating the safety, design, and operation of domestic nuclear power plants. The first part of the study describes the Federal and State regulatory procedures. It describes the legal foundations for the Federal licensing process and the associated State regulatory activities. It then analyzes the aspects of these procedures that affect the cost and supply of nuclear-generated electricity. The second part of this study examines the effects of nuclear safety regulations on the planning and construction lead time for nuclear power stations, the cost of nuclear power, and, ultimately, the decision to invest in nuclear power

  11. Radiochemical studies on nuclear fission at Trombay

    Indian Academy of Sciences (India)

    Asok Goswami

    2015-08-01

    Since the discovery of nuclear fission in the year 1939, both physical and radiochemical techniques have been adopted for the study of various aspects of the phenomenon. Due to the ability to separate individual elements from a complex reaction mixture with a high degree of sensitivity and selectivity, a chemist plays a significant role in the measurements of mass, charge, kinetic energy, angular momentum and angular distribution of fission products in various fissioning systems. At Trombay, a small group of radiochemists initiated the work on radiochemical studies of mass distribution in the early sixties. Since then, radiochemical investigations on various fission observables have been carried out at Trombay in , , and heavy-ion-induced fissions. An attempt has been made to highlight the important findings of such studies in this paper, with an emphasis on medium energy and heavy-ion-induced fission.

  12. magnetic order studied by nuclear methods

    CERN Document Server

    Reichl, C

    2001-01-01

    investigated within the frame of this work. The studies on the highly concentrated deuterides revealed a gradual loss in local field due to a distribution of 'local Curie temperatures' depending on the number of Fe neighbours and their distances from the Moessbauer nucleus. On rising the temperature, during a magnetic transition, an increasing number of Fe sites with different local environment loose their hyperfine fields, whereas bulk measurements showed a relatively sharp, however, incomplete transition. By using a combination of neutron diffraction- and muon spin relaxation studies the complex magnetic phase diagram of the system Ce(Rh,Ru) sub 3 B sub 2 , where weak magnetic moments exist, could be studied. There, transitions from para- to ferromagnetism, and more complicated magnetic structures could be observed. Due to the existence of several isotopes of B and Ru, each carrying different nuclear spins and magnetic moment, particularly complicated second moment simulations for interpreting the muon data...

  13. Nuclear cancellations follow-on study

    Energy Technology Data Exchange (ETDEWEB)

    1982-01-29

    The serious reduction in the aggregate commitment to nuclear power by US utilities over the past few years, as well as the serious stretchout of the completion schedules for many ongoing projects, has continued. A 1980 study which studied the factors causing this retrenchment is discussed. In this 1982 study, utilities were interviewed in an attempt to identify possible remedies which the Federal government might take to induce utilities to postpone rather than cancel units less than 10% complete, and to complete expeditiously units in the 10 to 60% completion range. The quality of the reserve margin is examined. The actions of state regulators are considered. Regulatory reform emerges as the key action the Federal government can take. (DLC)

  14. Effect of different root canal irrigants on the sealing ability of two all-in-one self-etch adhesives: An in vitro study

    OpenAIRE

    Rashi Agrawal; Shashi Prabha Tyagi; Rajni Nagpal; Chandrakar Chaman Mishra; Udai Pratap Singh

    2012-01-01

    Aim: To evaluate the effect of different root canal irrigants on the sealing ability of two self-etch adhesives, using dye penetration method, within the pulp chamber. Materials and Methods: 72 extracted human molars were divided into six groups, according to the irrigant and self-etch adhesives used. After de-roofing the pulp chamber with a carborundum disc, the pulp was extirpated using excavator and broaches. In 36 samples, pulp chambers were bonded with Xeno V after irrigation with ei...

  15. Comparative evaluation of antimicrobial activity of hydroalcoholic extract of Aloe vera, garlic, and 5% sodium hypochlorite as root canal irrigants against Enterococcus faecalis: An in vitro study

    OpenAIRE

    Swati Ramesh Karkare; Nivedita Pramod Ahire; Smita Uday Khedkar

    2015-01-01

    Introduction: Enterococcus faecalis are the most resistant and predominant microorganisms recovered from root canals of teeth where previous treatment has failed. Over the past decade, interest in drugs derived from medicinal plants has markedly increased. In dentistry, phytomedicines has been used as an anti-inflammatory, antibiotic, analgesic, sedative, and also as an endodontic irrigant. In endodontics, because of the cytotoxic reactions of most of the commercial intracanal medicaments and...

  16. Feasibility study on floating nuclear power station

    International Nuclear Information System (INIS)

    It is stipulated that nuclear power plants are to be built on solid rock bases on land in Japan. However, there are a limited number of appropriate siting grounds. The Central Research Institute of Electric Power Industry has engaged since 1981 in the studies on the construction technology of power plants, aiming at establishing new siting technology to expand the possible siting areas for nuclear power plants. Underground siting is regarded as a proven technology due to the experience in underground hydroelectric power plants. The technology of siting on quaternary ground is now at the stage of verification. In this report, the outline of floating type offshore/inshore siting technology is introduced, which is considered to be feasible in view of the technical and economical aspects. Three fixed structure types were selected, of which the foundations are fixed to seabed, plant superstructures are above sea surface, and which are floating type. Aiming at ensuring the aseismatic stability of the plant foundations, the construction technology is studied, and the structural concept omitting buoyancy is possible. The most practical water depth is not more than 20 m. The overall plant design, earthquake isolation effect and breakwater are described. (Kako, I.)

  17. Estudio del oído con TC Multidetector de 64 canales 64 - Detector CT findings in the study of the ear

    Directory of Open Access Journals (Sweden)

    María Lourdes Mallo

    2010-12-01

    Full Text Available El oído es una estructura anatómica compleja. Su estudio y comprensión resultan un reto diario para el radiólogo, siendo la tomografía computada una herramienta esencial para su estudio. La tomografía computada convencional con cortes finos en planos axiales y coronales permite una buena visualización de las diferentes estructuras. Sin embargo, se necesitan tiempos prolongados para su realización y posicionamientos incómodos o intolerables para muchos pacientes. Además la visualización de algunas de sus estructuras es limitada. La tomografía axial computada multidetector de 64 canales a nuestro medio permite optimizar el estudio de la compleja y pequeña anatomía del oído. La realización de adquisiciones volumétricas con cortes de 0,5 mm, con reconstrucciones multiplanares en los tres planos básicos, en planos curvos y reconstrucciones tridimensionales, hacen posible la visualización detallada de las estructuras en escasos segundos y en condiciones cómodas para el paciente. Nuestro propósito en este artículo es demostrar la utilidad de las reconstrucciones, particularmente en planos oblicuos, para identificar y analizar los diferentes reparos anatómicos del oído y alcanzar la visualización óptima de la anatomía relevante del hueso temporal.The ear is a complex anatomic structure. Its study and understanding represent a constant challenge for the radiologist. As a consequence the computed tomography becomes an essential tool for its examination. Conventional tomographic examination with both axial and coronal reconstruction of the image allows a satisfactory visualization of the different structures. However, the study requires long periods of time for its acquisition and uncomfortable or intolerable positions for the patients. Moreover, the characterization of some structures of the ear becomes limited. Sixty-four slice multidetector computed tomography allows the optimal study of the small and complex ear anatomy

  18. Neutronics analyses for fast spectrum nuclear systems and scenario studies for advanced nuclear fuel cycles

    OpenAIRE

    Grasso, Giacomo

    2010-01-01

    The present PhD thesis summarizes the three-years study about the neutronic investigation of a new concept nuclear reactor aiming at the optimization and the sustainable management of nuclear fuel in a possible European scenario. A new generation nuclear reactor for the nuclear reinassance is indeed desired by the actual industrialized world, both for the solution of the energetic question arising from the continuously growing energy demand together with the corresponding reduction of oil ava...

  19. Monte Carlo simulation of nuclear energy study (II). Annual report on Nuclear Code Evaluation Committee

    International Nuclear Information System (INIS)

    In the report, research results discussed in 1999 fiscal year at Nuclear Code Evaluation Committee of Nuclear Code Research Committee were summarized. Present status of Monte Carlo simulation on nuclear energy study was described. Especially, besides of criticality, shielding and core analyses, present status of applications to risk and radiation damage analyses, high energy transport and nuclear theory calculations of Monte Carlo Method was described. The 18 papers are indexed individually. (J.P.N.)

  20. 76 FR 50274 - Terrestrial Environmental Studies for Nuclear Power Stations

    Science.gov (United States)

    2011-08-12

    ...The U.S. Nuclear Regulatory Commission (NRC or the Commission) is issuing for public comment draft regulatory guide (DG), DG-4016, ``Terrestrial Environmental Studies for Nuclear Power Stations.'' This guide provides technical guidance that the NRC staff considers acceptable for terrestrial environmental studies and analyses supporting licensing decisions for nuclear power...

  1. Antibacterial Activity of Diode Laser and Sodium Hypochlorite in Enterococcus Faecalis-Contaminated Root Canals

    OpenAIRE

    Sohrabi, Khosrow; Sooratgar, Aidin; Zolfagharnasab, Kaveh; Kharazifard, Mohammad Javad; Afkhami, Farzaneh

    2015-01-01

    Introduction: The aim of the present in vitro study was to evaluate the disinfection ability of 980-nm diode laser in comparison with sodium hypochlorite (NaOCl) as a common root canal irrigant in canals infected with Enterococcus faecalis (E. faecalis). Methods and Materials: The root canals of 18 extracted single-rooted premolars were prepared by rotary system. After decoronation, the roots were autoclaved. One specimen was chosen for the negative control, and the remaining teeth were incub...

  2. Assessment of risks of stenosis of the anal canal during a prostatic radiotherapy

    International Nuclear Information System (INIS)

    The authors report a study which aimed at assessing the late tolerance of a prostatic irradiation at the rectum and anal canal level. They assessed the length of the rectum and of the anal canal after prostate irradiation or surgery in patients who suffered from a prostate adenocarcinoma. Data of 154 patients have been analyzed regarding the number of cases of stenosis of rectum or anal canal. They highlight the importance of the irradiated length and dose level. Short communication

  3. In vitro comparison of antimicrobial effectiveness of QMix and other final irrigants in human root canals

    OpenAIRE

    Ying Liu; Lili Guo; Yuqin Li; Xiangjun Guo; Bin Wang; Ligeng Wu

    2015-01-01

    Final root canal irrigation stands as an effective strategy for eliminating the dentin infection. This study aimed to investigate and compare the antibacterial efficacy of QMix and other four final irrigation regimens in reducing Enterococcus faecalis within human root canals. Single-canal human teeth contaminated with E. faecalis for 4 weeks were prepared chemomechanically with sodium hypochlorite (NaOCl). Then, the teeth were randomly assigned into six groups according to the final irrigati...

  4. INSTRUMENTATION OF CURVED CANALS: A REVIEW

    Directory of Open Access Journals (Sweden)

    Senthil Kumar

    2013-02-01

    Full Text Available INTRODUCTION: Nature seldom draws a straight line. Nowhere is thi s more apparent than in the anatomy of teeth roots and root canal systems o f human teeth. Even teeth with straight roots can harbor severely curved canals. Canal shapi ng is a critical aspect of endodontic treatment because it influences the outcome of the subsequent phases of canal irrigation and filling and the success of the treatment itself. In fact, curved canals are the most common endodontic complexity 1 . The need for some manner of root canal preparation pri or to root canal filling has long been recognized as an essential step in endodontic t reatment. Concepts concerning the role and purpose of this canal preparation, however, have differ ed remarkably at different times in the development of endodontics and in the hands of diffe rent practitioners 2

  5. Comparison of Irrigation Penetration into the Apical Part of Canals in Hand and Rotary Instrumentations

    Directory of Open Access Journals (Sweden)

    M. Khabiri

    2007-01-01

    Full Text Available Introduction: The penetration of irrigating solution to the apical one third of canals and removal of debris are dependent on the final size of the instruments and instrumentation techniques used in the canals. The purpose of this study was to evaluate the effect of final instrument size, on irrigation penetration into the apical part of canals in hand K-file instrumentation versus rotary system of Hero 642.Methods and Materials: The mesiobuccal canals of 48 first mandibular molar teeth were selected for this study. The teeth were divided into 2 groups of 24 in each and the mesiobuccal canals were instrumented by hand K-file or rotary system of Hero 642 at 2 stages. After each stage, a contrast medium was injected into the canals and radiographs were taken by RVG system. The irrigation penetration was measured in radiographs by Diamax software. The data were analyzed using t – student test.Results: This study showed that instrumentation up to # 25 file is not enough for irrigation penetration into the apical area. Also by more flaring the canals, more irrigating solution penetrates into the apical part of canals (P 0 0.001, but the difference between hand and rotary systems was not statistically significant (P > 0.05.Discussion: According to this study, instrumentation up to # 30 file results in better irrigation penetration into the apical area. The flaring of the canals is essential for better cleaning and irrigation of apical area.

  6. Radiographic Evaluation of Root and Canal Morphologies of Third Molar Teeth in Iranian Population

    Directory of Open Access Journals (Sweden)

    Faramarzi

    2013-06-01

    Full Text Available Background Root and canal morphology of teeth has a significant role in endodontic treatment success. Third molars have strategic roles after losing first and second molars. Objectives This study investigated the morphology of permanent third molar using radiography in Dentistry University of Hamadan during 2011. Materials and Methods In this experimental study, 352 extracted molars (179 maxillary and 173 mandibular molars were collected. After preparing access cavity and file placement in canals, to investigate the number of roots, canals and canal type periapical radiographies were taken from two directions (mesiodistal and buccolingual. The results were analyzed using SPSS version 16.0 software and descriptive statistics. Results According to the study on 173 mandibular third molars, 92.4%, 4.6%, and 2.89% had two, one, and three roots, respectively. Majority of them had two or three canals and most of mesial root canals were type 2; but in 179 maxillary third molars, findings showed that 67.6%, 15%, 11.7%, and 5.6% of teeth had three, one, two, and four roots, respectively, majority of which had three canals (68.7%. Canals of 100% of distobuccal and palatal roots and 91% of mesiobuccal roots were type 1. Conclusions However, root and canal anatomies of third molar teeth are unknown, but studies focusing on third molar teeth have shown their possibility of treatment.

  7. Decay heat studies for nuclear energy

    Science.gov (United States)

    Algora, A.; Jordan, D.; Taín, J. L.; Rubio, B.; Agramunt, J.; Caballero, L.; Nácher, E.; Perez-Cerdan, A. B.; Molina, F.; Estevez, E.; Valencia, E.; Krasznahorkay, A.; Hunyadi, M. D.; Gulyás, J.; Vitéz, A.; Csatlós, M.; Csige, L.; Eronen, T.; Rissanen, J.; Saastamoinen, A.; Moore, I. D.; Penttilä, H.; Kolhinen, V. S.; Burkard, K.; Hüller, W.; Batist, L.; Gelletly, W.; Nichols, A. L.; Yoshida, T.; Sonzogni, A. A.; Peräjärvi, K.

    2014-01-01

    The energy associated with the decay of fission products plays an important role in the estimation of the amount of heat released by nuclear fuel in reactors. In this article we present results of the study of the beta decay of some refractory isotopes that were considered important contributors to the decay heat in reactors. The measurements were performed at the IGISOL facility of the University of Jyväskylä, Finland. In these studies we have combined for the first time a Penning trap (JYFLTRAP), which was used as a high resolution isobaric separator, with a total absorption spectrometer. The results of the measurements as well as their consequences for decay heat summation calculations are discussed.

  8. European nuclear data studies for fast systems

    International Nuclear Information System (INIS)

    Nuclear data needs for fast systems are highlighted and the following projects are described: Joint European research projects: MUSE Experiments for Sub-critical Neutronics Validation; High- and Intermediate Energy Nuclear Data for ADS (HINDAS); and the Time-Of-Flight facility for Nuclear Data Measurements for ADS (nTOFNDADS); European Research Programme for the Transmutation of High Level Nuclear Waste in an Accelerator Driven System (EUROTRANS-NUDATRA); and CANDIDE; Programmes for transnational access to experimental facilities in Europe: European Facilities for Nuclear Data Measurements (EFNUDAT); Neutron Data Measurements at IRMM (NUDAME); European facility for innovative reactor and transmutation neutron data (EUFRAT) (P.A.)

  9. Display of nuclear medicine imaging studies

    International Nuclear Information System (INIS)

    Nuclear medicine imaging studies involve evaluation of a large amount of image data. Digital signal processing techniques have introduced processing algorithms that increase the information content of the display. Nuclear medicine imaging studies require interactive selection of suitable form of display and pre-display processing. Static imaging study requires pre-display processing to detect focal defects. Point operations (histogram modification) along with zoom and capability to display more than one image in one screen is essential. This album mode of display is also applicable to dynamic, MUGA and SPECT data. Isometric display or 3-D graph of the image data is helpful in some cases e.g. point spread function, flood field data. Cine display is used on a sequence of images e.g. dynamic, MUGA and SPECT imaging studies -to assess the spatial movement of tracer with time. Following methods are used at the investigator's discretion for inspection of the 3-D object. 1) Display of orthogonal projections, 2) Display of album of user selected coronal/ sagital/ transverse orthogonal slices, 3) Display of three orthogonal slices through user selected point, 4) Display of a set of orthogonal slices generated in the user-selected volume, 5) Generation and display of 3-D shaded surface. 6) Generation of volume data and display along with the 3-D shaded surface, 7) Side by side display orthogonal slices of two 3-D objects. Displaying a set of two-dimensional slices of a 3-D reconstructed object through shows all the defects but lacks the 3-D perspective. Display of shaded surface lacks the ability to show the embedded defects. Volume display -combining the 3-D surface and gray level volume data is perhaps the best form of display. This report describes these forms of display along with the theory. (author)

  10. Studies of fracture in nuclear graphite

    International Nuclear Information System (INIS)

    This work is directed towards establishing an improved understanding of the mechanisms which control fracture in nuclear graphites. Fracture has been studied dynamically by straining graphite specimens on the stage of an optical microscope. Semi-quantitative fracture data were obtained by monitoring the acoustic emission (AE) response of a wide range of polygranular graphites, whilst the application of Linear Elastic Fracture Mechanics (LEFM) has yielded quantitative data. Changes in Young's Modulus and strength of Civil Advanced Gas-Cooled Reactor (CAGR) fuel sleeve graphite irradiated to 22 GWd/Te (approximately 6% wt. loss) are reported. The AE response of irradiated graphite has been investigated and the observed changes explained in terms of the known changes to microstructure and mechanical properties caused by fast neutron hardening and radiolytic oxidation. A new fracture model for nuclear graphites, which has a microstructural basis combined with a fracture mechanics type failure criterion, and which considers the crack like nature of pores in graphite is developed. The model accurately predicts the distribution of tensile failure stresses for CAGR fuel sleeve graphite and qualitatively predicts the AE response of graphite and the reduction of strength due to radiolytic oxidation. (author)

  11. The incidence and configuration of the bifid mandibular canal in Koreans by using cone-beam computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Ju Han; Lee, Kook Sun; Oh, Min Gyu; Choi, Hwa Young; Lee, Sae Rom; Oh, Song Hee; Choi, Yoon Joo; Kim, Gyu Tae; Choi, Yong Suk; Hwang, Eui Hwan [Dept. of Oral and Maxillofacial Radiology, School of Dentistry, Kyung Hee University, Seoul (Korea, Republic of)

    2014-03-15

    This study was performed to investigate the incidence and configuration of the bifid mandibular canal in a Korean population by using cone-beam computed tomography (CBCT) imaging. CBCT images of 1933 patients (884 male and 1049 female) were evaluated using PSR-9000N and Alphard-Vega 3030 Dental CT units (Asahi Roentgen Ind. Co., Ltd, Kyoto, Japan). Image analysis was performed by using OnDemand3D software (CyberMed Inc., Seoul, Korea). The bifid mandibular canal was identified and classified into four types, namely, the forward canal, buccolingual canal, dental canal, and retromolar canal. Statistical analysis was performed by using the chi-squared test and one-way analysis of variance (ANOVA). Bifid mandibular canals were observed in 198 (10.2%) of 1933 patients. The most frequently observed type of bifid mandibular canal was the retromolar canal (n=104, rate: 52.5%) without any significant difference among the incidence of each age and gender. The mean diameter of the accessory canal was 1.27 mm (range: 0.27-3.29 mm) without any significant difference among the mean diameter of each type of the bifid mandibular canal. The mean length of the bifid mandibular canals was 14.97mm(range: 2.17-38.8 mm) with only a significant difference between the dental canal and the other types. The bifid mandibular canal is not uncommon in Koreans and has a prevalence of 10.2% as indicated in the present study. It is suggested that a CBCT examination be recommended for detecting a bifid canal.

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

    Science.gov (United States)

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

    2013-04-01

    The research investigates the field methodologies to evaluate water losses from canals, in order to find a reliable method to identify and quantify them. This study was conducted in five canal lines in Piedmont, north-western Italy, different for hydraulic, morphological, geological and hydrogeological contexts (De Luca et alii, 2012). At a regional scale, Piedmont network consists of several tens of thousands km of irrigation canals. The loss of water due to seepage from irrigation canals constitutes a substantial part of the usable water. Irrigation canals placed in natural soil or fine and coarse sediments are characterized by water losses ranging from 20 % to more than 50 %. These losses cause economic, hydrogeological and environmental consequences: water losses evaluation from irrigation canals in the basis for the sustainable water resource use and management. First, hydrogeological and hydrological characterisation of the study area and of the bottom of the irrigation canals was carried out for every investigated canal, in order to evaluate the relationships between groundwater and stream water (eg. piezometric and hydrogeochemical survey campaigns, infiltrometry tests, penetrometric tests and electrical tomographies, soil characterizations from the bottom of investigated canals). The canals seepage rates were subsequently estimated using different methodologies: empirical formulas, inflow-outflow tests and double tracer tests. The empirical formulas applied for the study underestimated the real amount of the losses probably due to the scarce number of the considered variables. Then the canals seepage rates were evaluated employing inflow-outflow tests, considered the best tool by several authors. This method allows the determination of seepage quantities measuring inflow and outflow of a canal test reach either by instruments. The canal discharge was evaluated using a current meter. This method, even if easy to apply and practical, is not efficient

  13. Radiographic evaluation of the course and visibility of the mandibular canal

    International Nuclear Information System (INIS)

    This study was performed to investigate the course of the mandibular canal on panoramic radiography and the visibility of this canal on both panoramic radiography and cone-beam computed tomography (CBCT). The study consisted of panoramic radiographs and CBCT images from 262 patients. The course of the mandibular canal, as seen in panoramic radiographs, was classified into four types: linear, elliptical, spoon-shaped, and turning curves. The visibility of this canal from the first to the third molar region was evaluated by visually determining whether the mandibular canal was clearly visible, probably visible, or invisible. The visibility of the canal on panoramic radiographs was compared with that on CBCT images. Elliptical curves were most frequently observed along the course of the mandibular canal. The percentage of clearly visible mandibular canals was the highest among the spoon-shaped curves and the lowest among the linear curves. On panoramic radiographs, invisible mandibular canals were found in 22.7% of the examined sites in the first molar region, 11.8% in the second molar region, and 1.3% in the third molar region. On CBCT cross-sectional images, the mandibular canal was invisible in 8.2% of the examined sites in the first molar region, 5.7% in the second molar region, and 0.2% in the third molar region. The visibility of this canal was lower in the first molar region than in the third molar region. The mandibular canal presented better visibility on CBCT images than on panoramic radiographs.

  14. Comparación de Controladores de Nivel para Canales Abiertos Basados en un Modelo por Colocación A Comparative Study between Level Controllers for Open Channels Based on a Collocation Model

    Directory of Open Access Journals (Sweden)

    Jean F Dulhoste

    2007-01-01

    Full Text Available El propósito del presente estudio es comparar el funcionamiento de controladores no lineales de nivel para canales abiertos. La dinámica del flujo en canales abiertos normalmente se representa mediante las ecuaciones de Saint-Venant. En este trabajo se presentan tres leyes de control no lineal que se desarrollaron a partir de un modelo de colocación. Las leyes incluidas son: linealización entrada salida, linealización entrada salida dinámica y linealización por realimentación escalonada (backstepping. Se implementó un simulador unidimensional para resolver las ecuaciones de Saint-Venant, lo que permitió estudiar el comportamiento del sistema controlado. Los resultados de funcionamiento mostraron que la técnica de linealización entrada-salida dinámica parece ser la mejor de las tres estudiadas y que éstas técnicas muestran ser bastante precisas en los casos estudiados.This paper proposed a comparative study between different nonlinear control techniques for level regulation in an open channel. Flow dynamics in a canal can be modeled by Saint-Venant equations. In this paper three control laws derived from a collocation model are presented. These laws are: input output linearization, dynamic input output linearization, and backstepping. A one-dimensional simulator that solves Saint-Venant’s equations was implemented, allowing to study the controlled system. The results showed that the dynamic input output linearization control technique was the best among the studied control techniques, and that these techniques are reliable in the cases studied.

  15. Contemporary root canal filling strategies

    NARCIS (Netherlands)

    A.T. Moinzadeh

    2016-01-01

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

  16. Canal Water Scarcity Hits Farmers

    Institute of Scientific and Technical Information of China (English)

    张忠潮

    2007-01-01

    Acute shortage of canal water for irrigation in this district has caused resentment among the farmers.The water is being released in the various channels for just one week in a month,which is not enough to meet the irrigation needs of the farmers who are preparing their fields for paddy

  17. Sandia nuclear-power-plant siting study

    International Nuclear Information System (INIS)

    NRC's Siting Analysis Branch requested Sandia National Laboratories to provide technical guidance for establishing (1) numerical criteria for population density and distribution surrounding future nuclear power plant sites and (2) standoff distances from plants for offsite hazards. The first task involved analyses in four areas, each of which could play a role in evaluating the impact of a siting policy. The four areas were risks from possible plant accidents, population distribution characteristics for existing sites, availability of sites, and socioeconomic impacts. The second task had two areas of concern: determination of which classes of offsite hazards are amenable to regulation by fixed standoff distances, and review of available models for the determination of appropriate standoff distances. Results, conclusions, and recommendations of the study are summarized

  18. Sandia nuclear power plant siting study

    International Nuclear Information System (INIS)

    NRC's Siting Analysis Branch requested Sandia National Laboratories to provide technical guidance for establishing (1) numerical criteria for population density and distribution surrounding future nuclear power plant sites and (2) standoff distances from plants for offsite hazards. The first task involved analyses in four areas, each of which could play a role in evaluating the impact of a siting policy. The four areas were risks from possible plant accidents, population distribution characteristics for existing sites, availability of sites, and socioeconomic impacts. The second task had two areas of concern: determination of which classes of offsite hazards are amenable to regulation by fixed standoff distances, and review of available models for the determination of appropriate standoff distances. Results, conclusions, and recommendations of the study are summarized

  19. Long-term clinical evaluation of endodontically treated teeth by 15 F CO2 laser microprobe: three years clinical follow-up of 1512 root canals--in-vivo study

    Science.gov (United States)

    Kesler, Gavriel; Koren, Rumelia; Kesler, Anat; Hay, Nissim; Gal, Rivka

    1999-05-01

    The purpose of this study was to determine the efficiency of 15 F CO2 laser microprobe, in cases of periapical lesions, by eliminating the pathological reaction caused by certain species of bacteria, reduction of reinfection and stimulation of osteogenesis in the periapical region. Until now, no suitable delivery fiber existed for CO2 laser endodontic radiation in the apical region where it is most difficult to eliminate the pulp tissue using conventional methods. To overcome this problem, Sharplan laser designed a microprobe that reaches closer to the apex, distributing the energy density to a smaller area of the root canal, thus favorably increasing the thermal effects. The study was conducted on 900 teeth, divided in two groups. 468 were new case, carefully selected according to strict parameters such as: wide periapical translucency over 1mm, supported by digital x-ray, with a lesion of 3mm and more. All root canals were mechanically prepared in the conventional method up to size 35, Physiological saline solution served as finding solution and were treated by 15 F CO2 laser microprobe for 60 pulses repeatedly. The temperature at the surrounding tissue of the root did not exceed 38 degrees C filling of the canal was possible at the same appointment, without antibiotical treatment. 432 of the cases, which were referred to us by other dentists, after an unsuccessful treatment according to the classical therapy, were treated by the same laser therapy. Follow up was performed by clinical examination, and digital x-ray taken, during and after treatment as well as after 3, 6, 9, 12 month. The result demonstrate 98% success rate in both study groups, according to objective criteria for a successful treatment such as: reduction of apical translucency after 2- 6 months, freedom form clinical complains, and no need for periapical surgery.

  20. Correlation between symptoms and sagittal alignment parameters in patients with lumbar canal stenosis: a case-control study Correlación entre síntomas y parámetros de alineación sagital en pacientes con estenosis del canal lumbar: un estudio de control de casos Correlação entre os sintomas e os parâmetros de alinhamento sagital em pacientes com estenose do canal lombar: estudo de caso-controle

    Directory of Open Access Journals (Sweden)

    Paulo Tadeu Maia Cavali

    2012-12-01

    Full Text Available OBJECTIVE: To examine the relationship between sagittal balance parameters and different symptoms of spinal disease in patients with lumbar canal stenosis (LCS and controls. METHODS: In this prospective, diagnostic, case-control study, we included all patients consecutively admitted to a public teaching hospital for surgical treatment of LCS between July 2010 and October 2011, aged more than 40 years, with back pain plus radiculopathy or neurogenic claudication, and controls without LCS. Magnetic resonance and x-rays allowed the measurement of sagittal axis parameters. Clinical data, the Oswestry Disability Index and the visual analogue scale of pain were assessed. RESULTS: 23 patients were in the Stenosis group, and 17 were controls. The Stenosis group presented lower values of total lumbopelvic lordosis and regional lordosis L1, L2 and L3. In LCS patients and back pain, total lumbopelvic and regional lordosis at L1, L2 and L3 were smaller. Those with stenosis and radiculopathy had higher values of pelvic tilt and lower total lumbopelvic lordosis and regional lordosis in L1 and L2. In patients with claudication, regional lumbopelvic lordosis in L1 and L2 and the T9 sagittal offset were smaller. All patients with pain had higher values of thoracic kyphosis, regional lumbopelvic lordosis in L1, lower values for pelvic tilt, sagittal T1 offset, sacro-femoral distance and overhang compared to patients without pain. CONCLUSIONS: This study shows significant correlations between symptoms and sagittal axis parameters between patients with and without spinal canal stenosis and also in subgroups of the patients with stenosis with different complaints.OBJETIVO: Analizar la relación entre los parámetros del equilibrio sagital y los diversos síntomas de enfermedad espinal en pacientes con estenosis del canal lumbar (ECL y sus controles. MÉTODOS: En esta perspectiva, de estudio de diagnóstico, de control de casos, incluimos a todos los pacientes

  1. Shaping ability of Quantec Series 2000 rotary nickel-titanium instruments in simulated root canals: Part 2.

    Science.gov (United States)

    Thompson, S A; Dummer, P M

    1998-07-01

    The aim of this laboratory based study was to determine the shaping ability of Quantec Series 2000 nickel-titanium rotary instruments in simulated root canals. A total of 40 canals with four different shapes in terms of angle and position of curve were prepared with Quantec Series 2000 instruments using the technique recommended by the manufacturer. Part 2 of this report describes the efficacy of the instruments in terms of prevalence of canal aberrations, the amount and direction of canal transportation and overall post-operative shape. Pre- and post-operative images of the canals were taken using a video camera attached to a computer with image analysis software. The pre- and post-operative views were superimposed to highlight the amount and position of material removed during preparation. Twenty-one zips and elbows were created during preparation with a significant difference (P canal shapes in terms of the incidence of aberrations. Four perforations were created, with significant differences (P canal shapes; three ledges were also created but no danger zones. Highly significant differences (P canal shapes in total canal width at specific points along the canal length and in the amount of resin removed from the inner and outer aspects of the curve. Canal transportation at the end-point of preparation was most frequently directed towards the outer aspect of the curve, and without exception in canals with 40 degrees curves. At the beginning of the curve, transportation became more evenly balanced between the inner and outer aspect of the curve, although predominated towards the outer. Transportation was generally directed towards the outer at the orifice, especially in canals with 40 degrees curves. Mean absolute transportation at the various measurement points was less than 0.11 mm; significant differences occurred between canal shapes at the end-point of preparation (P canals. PMID:9823116

  2. Shaping ability of Lightspeed rotary nickel-titanium instruments in simulated root canals. Part 2.

    Science.gov (United States)

    Thompson, S A; Dummer, P M

    1997-12-01

    The aim of this laboratory based study was to determine the shaping ability of Lightspeed nickel-titanium rotary instruments in simulated root canals. A total of 40 canals with four different shapes in terms of angle and position of curve were prepared with Lightspeed instruments using the stepback technique recommended by the manufacturer. This report describes the efficacy of the instruments in terms of prevalence of canal aberrations, the amount and direction of canal transportation, and overall postoperative shape. Preoperative and postoperative images of the canals were taken using a video camera attached to a computer with image analysis software. The preoperative and postoperative views were superimposed to highlight the amount and position of material removed during preparation. Only one (2.5%) zip and one elbow were created, with no ledges, perforations, danger zones, or blockages being produced. At specific points along the canal length there were highly significant differences (p canal shapes in total canal width and in the amount of resin removed from the inner and outer aspects of the curve. The direction of canal transportation at the end point of preparation was most frequently toward the outer aspect of the curve; although in half of the canals, transportation was either directed toward the inner aspect or not observed. At the apex of the curve, the beginning of the curve, and halfway to the orifice, transportation was reversed with the majority of canals being transported toward the inner aspect of the curve. Mean absolute transportation was small and was below 0.06 mm at every position except the orifice. Overall, Lightspeed rotary instruments prepared canals well and would appear to be a valuable addition to the endodontic armamentarium. PMID:9487850

  3. Studies and research concerning BNFP. Nuclear spent fuel transportation studies

    International Nuclear Information System (INIS)

    Currently, there are a number of institutional problems associated with the shipment of spent fuel assemblies from commercial nuclear power plants: new and conflicting regulations, embargoing of certain routes, imposition of transport safeguards, physical security in-transit, and a lack of definition of when and where the fuel will be moved. This report presents a summary of these types and kinds of problems. It represents the results of evaluations performed relative to fuel receipt at the Barnwell Nuclear Fuel Plant. Case studies were made which address existing reactor sites with near-term spent fuel transportation needs. Shipment by either highway, rail, water, or intermodal water-rail was considered. The report identifies the impact of new regulations and uncertainty caused by indeterminate regulatory policy and lack of action on spent fuel acceptance and storage. This stagnant situation has made it impossible for industry to determine realistic transportation scenarios for business planning and financial risk analysis. A current lack of private investment in nuclear transportation equipment is expected to further prolong the problems associated with nuclear spent fuel and waste disposition. These problems are expected to intensify in the 1980's and in certain cases will make continuing reactor plant operation difficult or impossible

  4. Nuclear magnetometry studies of spin dynamics in quantum Hall systems

    Science.gov (United States)

    Fauzi, M. H.; Watanabe, S.; Hirayama, Y.

    2014-12-01

    We performed a nuclear magnetometry study on quantum Hall ferromagnet with a bilayer total filling factor of νtot=2 . We found not only a rapid nuclear relaxation but also a sudden change in the nuclear-spin polarization distribution after a one-second interaction with a canted antiferromagnetic phase. We discuss the possibility of observing cooperative phenomena coming from nuclear-spin ensemble triggered by hyperfine interaction in quantum Hall system.

  5. Nuclear deterrence in second tier nuclear weapon states: a case study of India

    International Nuclear Information System (INIS)

    Nuclear deterrence today anchors the national security of all states that possess nuclear weapons. Certain principles or requirements of nuclear deterrence are the same for all such countries. For instance, the ability to threaten with unacceptable damage, or the ability to raise the costs of an action that an adversary might want to take by threatening punishment that would make the act seem meaningless and even regrettable. But must every nuclear nation indulge in an exercise of large-scale warhead accumulation or yield refinements through nuclear testing, or creation of elaborate nuclear war fighting plans in order to claim credible deterrence? Can the practice of deterrence in the second tier states follow a different course? The study examines the manner in which India is engaged in constructing a credible and stable deterrence relationship with two of its nuclear armed adversaries, Pakistan and China with an arsenal much smaller, and command and control structures far simpler than in any of the P-5 nations. Does this difference impact the nature of its nuclear deterrence? In its efforts at creating and sustaining credible nuclear deterrence should India necessarily be expected to follow the same path and rules as those of the P-5? Would it be compelled to build hundreds of warheads and a huge weapons infrastructure? Would a deterrence based on anything less not be credible or stable? The study concludes that even countries with small nuclear arsenals behave no differently from states that possess several thousands of such weapons. The assumption that small nuclear arsenals and rudimentary command and control lend themselves to temptations of easy nuclear use is misplaced. Credible nuclear deterrence between India and Pakistan or India and China would hold on the same bases it has held elsewhere - fear of nuclear destruction, imposition of unacceptable damage, and the ability to rationally calculate and weigh the benefits against the costs of use of nuclear

  6. Introducing Knowledge Management in Study Program of Nuclear Engineering

    International Nuclear Information System (INIS)

    Nuclear engineering is the branch of engineering concerning application of the fission as well as the fusion of atomic nuclei, and the application of other sub-atomic physics, based on the principles of nuclear physics. In the sub-field of nuclear fission there are many investigations of interactions and maintaining of systems and components like nuclear reactors and nuclear power plants. The field also includes the study of different applications of ionizing radiation (medicine, agriculture...), nuclear safety, the problems of thermodynamics transport, nuclear materials and nuclear fuels, and other related technologies like radioactive waste management. In the area of nuclear science and engineering a big amount of knowledge has been accumulated over the last decades. Different levels of nuclear knowledge were considered in different ways and they were taught to different parts of population as a general human culture and as a general scientific-technical-technological culture (high schools, nuclear information centres, training centres, universities...). An advanced level of nuclear knowledge has been accumulated by many experienced workers, specialists and experts in all nuclear and nuclear-related fields and applications. In the last 20 years knowledge management has established itself as a discipline of enabling individuals, teams and whole organizations to create, share and apply knowledge collectively and systematically, with goal to better achieve their objectives. Also, knowledge management became key strategic approach for management of intellectual assets and knowledge that can improve safety, efficiency and innovation, and lead to preserve and enhance current knowledge. Knowledge management could be applied in education, training, networking, human resource development and capacity building, sharing, pooling and transferring knowledge form centres of knowledge to centres of growth. Considering the critical importance of nuclear knowledge it is important

  7. Bioceramic-Based Root Canal Sealers: A Review

    Directory of Open Access Journals (Sweden)

    Afaf AL-Haddad

    2016-01-01

    Full Text Available Bioceramic-based root canal sealers are considered to be an advantageous technology in endodontics. The aim of this review was to consider laboratory experiments and clinical studies of these sealers. An extensive search of the endodontic literature was made to identify publications related to bioceramic-based root canal sealers. The outcome of laboratory and clinical studies on the biological and physical properties of bioceramic-based sealers along with comparative studies with other sealers was assessed. Several studies were evaluated covering different properties of bioceramic-based sealers including physical properties, biocompatibility, sealing ability, adhesion, solubility, and antibacterial efficacy. Bioceramic-based sealers were found to be biocompatible and comparable to other commercial sealers. The clinical outcomes associated with the use of bioceramic-based root canal sealers are not established in the literature.

  8. Bioceramic-Based Root Canal Sealers: A Review

    Science.gov (United States)

    Che Ab Aziz, Zeti A.

    2016-01-01

    Bioceramic-based root canal sealers are considered to be an advantageous technology in endodontics. The aim of this review was to consider laboratory experiments and clinical studies of these sealers. An extensive search of the endodontic literature was made to identify publications related to bioceramic-based root canal sealers. The outcome of laboratory and clinical studies on the biological and physical properties of bioceramic-based sealers along with comparative studies with other sealers was assessed. Several studies were evaluated covering different properties of bioceramic-based sealers including physical properties, biocompatibility, sealing ability, adhesion, solubility, and antibacterial efficacy. Bioceramic-based sealers were found to be biocompatible and comparable to other commercial sealers. The clinical outcomes associated with the use of bioceramic-based root canal sealers are not established in the literature. PMID:27242904

  9. Mandibular Second Premolar with Four Canals

    Directory of Open Access Journals (Sweden)

    Javad Ghiasi

    2015-09-01

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

  10. Effects of irrigation solutions and Calcium hydroxide dressing on root canal treatments of periapical lesions

    Directory of Open Access Journals (Sweden)

    Vita Nirmala

    2006-03-01

    Full Text Available The preparation of root canal in endodontic treatment plays an important role in treating non vital teeth with periapical lesion. Some factors influence the success of root canal treatment in short and long terms are the irrigation of root canal using antiseptic solution and the use of root canal medicament. The aim of this literature study is to determined the effect of irrigation solution and Calcium hydroxide dressing in root canal treatment of periapical lesions. The use of root canal medicament during the endodontic treatment could sterilized and decreased the number of pathogenic microorganism of root canal. An effective root canal irrigation solution must be able to dissolve organic and anorganic debris, lubricate endodontic instruments, disinfect microorganisms, non toxic and economical. The best irrigation solution has maximum antimicrobial effect with minimum toxicity. Division of calcium hydroxide into Calcium and hydroxyl ions is responsible for alkalinization of cavity, subsequently it makes the condition of cavity to be inappropriate for bacterial endotoxin in vitro as well as in vivo, and considered as the only clinically effective medicament in inactivating bacterial endotoxin. Calcium hydroxide is the only medication which has the ability to clinically inactive bacterial endotoxin in vitro in vivo and accepted as the best of root canal medication.

  11. Comparison of two stainless steel files to shape simulated root canals.

    Science.gov (United States)

    al-Omari, M A; Bryant, S; Dummer, P M

    1997-01-01

    The aim of this study was to compare the shaping ability of two stainless steel files using simulated canals. A total of 80 simulated canals of various angles and positions of curvature were prepared by hand using either Mani K-Files or Micro Mega K-Files. Following orifice enlargement each file type was used to prepare 40 canals employing a linear filing motion and an anticurvature stepback technique. Pre- and post-operative longitudinal images of the canals were taken with a video camera and stored and manipulated in a computer with image analysis software. The presence of canal aberrations and the amount of material removed as a result of preparation were determined from composite images of superimposed pre- and post-operative views. Overall, canal preparation with Mani K-Files was significantly quicker (P danger zones. Micro Mega K-Files created significantly wider (P Canal shape had a significant influence on preparation time (P danger zones (P canals with better shapes. Original canal shape had a substantial influence on the outcome of shaping procedures. PMID:9477792

  12. Groundwater quality and soil salinization in a canal command area and management options

    International Nuclear Information System (INIS)

    This study was undertaken to examine the groundwater quality and soil salinization in canal irrigated areas. Data were collected along six secondary canals (2 each at head, middle and tail end) of a main canal and nine tertiary canals (3 each at head, middle and tail) on each of the secondary canal. The farmers were also interviewed to investigate the impact of location along the irrigation channels on their crop yield and income. The results showed that groundwater quality has deteriorated from head to tail reaches of the irrigation channels i.e. the main canal, the secondary and the tertiary canals. Similarly, the soil salinization has increased with increase in distance from the head of the irrigation system along all the irrigation channels. Location of the water users along the canal irrigation system has significant impact on their crop yield as well as income and these parameters decrease with increase in distance from the head of the irrigation channels. The net income of the tail end farmers is only 43-59% of the head end farmers. The reduced canal water supply at lower reaches of the irrigation system forced the down reach water users to pump more groundwater of inferior quality resulting in many times increase in their irrigation cost. The deteriorating groundwater quality further added misery to the downstream farmers by degrading productivity of their lands due to increased soil salinity. (author)

  13. The levels of heavy metals in water and all aquatic in Ismailia canal, (Egypt) compared with the international permissible limits and accumulative studies for these metals in biota

    International Nuclear Information System (INIS)

    The concentration of Pb, Cd, Cu, Zu, Ni, Fe and Mn were determined in water, and in different organs of fishes, bivalves, snails and plants in Ismailia canal, Egypt. Moreover, accumulation of the investigated heavy metals by aquatic biota in Ismailia canal and the concentration factor values for this accumulation were calculated to qualify the degree of pollution and compare these levels with the international permissible limits. Results showed that Pb, Cd, Cu and Zn were exceeded the permissible limits especially in the industrial area of Abu- Zaabal, Kalubia governorate. The relative order of heavy metal levels in the canal water was: Fe>Mn>Pb>Zn>Ni>Cd>Cu.Accumulation of heavy metals by the aquatic biota was determined. The accumulation of heavy metals by common snails, namely physa acuta and biomphalaria alexandrina and the bivalve oyster Caelatura (caelatura) companyoi was found mainly in the edible parts (soft parts), whereas, the accumulation by their shells, which are mainly formed of calcium carbonate was via adsorption and surface complexation, since all the accumulated heavy metals were released by adding 0.1 M HCl for few minutes . Moreover, accumulation of heavy metals by common plants namely water hyacinth plant (Eichhornia crassipes) and freshwater weeds were determined. It was found that the accumulation of heavy metals was higher in roots than in leaves. On the other hand, the accumulation of heavy metals by common fish namely, Oreochromis niloticus (Nile Tilapia) was measured in its organs : muscles, liver, gills and gonads. It was found that there is variation of distribution of heavy metals among fish organs. Since the high accumulation of heavy metals among the investigated biota, they can be used as biological indicator for pollution of heavy metals in aquatic ecosystem . The average values and standard deviation for all measurements were determined. Data obtained were compared with the permissible concentrations of the environmental protection

  14. [Electromagnetic studies of nuclear structure and reactions

    International Nuclear Information System (INIS)

    The experimental goals are focused on developing an understanding of strong interactions and the structure of hadronic systems by determination of the electromagnetic response; these goals will be accomplished through coincidence detection of final states. Nuclear modeling objectives are to organize and interpret the data through a consistent description of a broad spectrum of reaction observables; calculations are performed in a nonrelativistic diagrammatic framework as well as a relativistic QHD approach. Work is described according to the following arrangement: direct knockout reactions (completion of 16O(e,e'p), 12C(e,e'pp) progress, large acceptance detector physics simulations), giant resonance studies (intermediate-energy experiments with solid-state detectors, the third response function in 12C(e,e'p0) and 16O(e,e'p0), comparison of the 12C(e, e'p0) and 16O(e,e'p3) reactions, quadrupole strength in the 16O(e,e'α0) reaction, quadrupole strength in the 12C(e,e'α) reaction, analysis of the 12C(e,e'p1) and 16O(e,e'p3) angular distributions, analysis of the 40Ca(e,e'x) reaction at low q, analysis of the higher-q 12C(e,e'x) data from Bates), models of nuclear structure (experimental work, Hartree-Fock calculations, phonon excitations in spherical nuclei, shell model calculations, variational methods for relativistic fields), and instrumentation development efforts (developments at CEBAF, CLAS contracts, BLAST developments)

  15. A study on international nuclear cooperation and technology self-reliance strategies for nuclear development in other countries

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Young Myung; Han, Pil Soon; Park, Yun Sik; Song, Ki Dong; Yang, Mang Ho; Oh, Keun Bae; Jang, Hong Lae; Lee, Dong Jin; Lee, Kang Suk; Kim, Sung Ki; Ko, Han Suk [Korea Atomic Energy Res. Inst., Taejon (Korea, Republic of)

    1993-12-01

    This study deals with international nuclear cooperation and technology self-reliance for nuclear development in other countries. This study also analyses the international and domestic nuclear environment such as NPT, nuclear export control, gloval environmental issues, and public acceptance. Finally, a suggestion is made for the future direction of strategy for nuclear technology self-reliance in Korea. (Author).

  16. A Study on the Enforcement of Korean Nuclear Legal System

    International Nuclear Information System (INIS)

    Recently, the reform of nuclear legal system requires the adaptation of the new paradigm while the use of nuclear revitalize in domestic and global society. In this study, we investigated the relationship of nuclear legal system and related laws in Korea, and compared with the administration and legal system of nuclear in major developed countries. And we suggested the representative factors of the environmental changes related to atomic act in Korea recently. The major contents of the atomic energy law in order to meet the new environment of nuclear are following as; - the items for nuclear law presented intermediate and long term basic direction of the national nuclear policy with binding authority. - the items for the efficient support of nuclear R and D - the items for efficient regulation of nuclear reactor - the items for efficient regulation of nuclear fuel cycle - the items for strict radiation protection - the items for the export support of the nuclear technology including the nuclear power plant and etc. - the items for the support of processing and disposal facilities of high level radioactive waste - the items for the nuclear spent fuel policy of transparency and the clear decision-making structure

  17. The study on the microbiologic of root canals with different severity of infection%不同感染程度根管内微生物分析

    Institute of Scientific and Technical Information of China (English)

    周琦; 李军心; 钟波; 张晓洁; 江双风

    2016-01-01

    目的:采用细菌培养技术比较不同感染程度根管内微生物组成。方法:选择四种不同感染程度根管各5例:有瘘管的慢性根尖周炎、无瘘管的慢性根尖周炎、根管治疗失败后的根尖周炎、根管治疗欠填但无根尖暗影五年以上。所有样本进行根管内取样、后培养鉴定根管内的细菌种类。结果:根管治疗欠填但无根尖暗影五年以上的根管样本中细菌检出率明显低于其他对照组,但粪肠球菌仍有较高检出率。结论:根管治疗欠填但多年观察无根尖暗影的患牙根管环境相对简单但仍有潜在致病的可能。%Objective: To compare the patterns of microbial infection of root canals with different severity of infection. Methods: The intraradicular biofilm samples were collected from 4 different kinds of root canal:periapical periodontitis with fistula, periapical periodontitis without fistula, underfilling teeth with periapical infection after endodontic treatmentand underfilling teeth without periapical infection after endodontic treatment for at least 5 years. The samples were taken from the canal, cultivated and de-tected. Results: In underfilling teeth without periapical infection after endodontic treatment, the com-positon of the microbial flora is relatively simple, but enterococcus faecalis still exist in some of root canals. Conclusions: Underfilling teeth without periapical infection after endodontic treatment shows a relatively simple situation, but still has the risk of becoming periapical periodontitis.

  18. Feasibility Study on Nuclear Propulsion Ship according to Economic Evaluation

    International Nuclear Information System (INIS)

    The use of nuclear ships has been extending to the icebreaker, the deep-water exploration ship, and the floating nuclear power plant. Prior to developing the new ship, the relevant regulations need to be considered. In this study, we reviewed the nuclear ship-related regulations. In addition, economic value is one of the most important factors which should be considered in the pre-design phase. To evaluate the economics of the nuclear ship, we calculated Capital Expenditure (abbreviated as CAPEX) and Operation Expenditure (abbreviated as OPEX) for various types of ships. We reviewed the nuclear ship-related regulations and evaluated the economics of the nuclear ship compared to the diesel ship. The calculation result shows that economic feasibility of the nuclear ship depends on the oil price as well as the cost of the nuclear reactor

  19. Feasibility Study on Nuclear Propulsion Ship according to Economic Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Gil, Youngmi; Yoo, Seongjin; Oh, June; Byun, Yoonchul; Woo, Ilguk [Daewoo Shipbuilding and Marine Engineering Co., Ltd, Seoul (Korea, Republic of); Kim, Jiho; Choi, Suhn [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-05-15

    The use of nuclear ships has been extending to the icebreaker, the deep-water exploration ship, and the floating nuclear power plant. Prior to developing the new ship, the relevant regulations need to be considered. In this study, we reviewed the nuclear ship-related regulations. In addition, economic value is one of the most important factors which should be considered in the pre-design phase. To evaluate the economics of the nuclear ship, we calculated Capital Expenditure (abbreviated as CAPEX) and Operation Expenditure (abbreviated as OPEX) for various types of ships. We reviewed the nuclear ship-related regulations and evaluated the economics of the nuclear ship compared to the diesel ship. The calculation result shows that economic feasibility of the nuclear ship depends on the oil price as well as the cost of the nuclear reactor.

  20. A study on enhancing policy transparency in the nuclear field

    Energy Technology Data Exchange (ETDEWEB)

    Cheon, S. W. [Korea Institute for National Unification, Seoul (Korea)

    2000-11-01

    Enhancing transparency in the nuclear field is a pending issue for the South Korea's nuclear community. International suspicions and mistrust of ROK's nuclear activities have been obstacles to the developments of South Korea's nuclear industry. South Korea's efforts have not been sufficient enough to ensure international community that its nuclear program will be used solely for peaceful purposes. Therefore, the purpose of this study is to conduct a positive and creative research on the issue of transparency and provide policy options that are conducive to developing of South Korea's nuclear industry. Based on an in-depth study on transparency of national policies, this study presents a package of detail policy measures that can contribute to enhancing transparency in the nuclear filed. 75 refs., 2 tabs. (Author)

  1. Study of a Federal Nuclear Operations Corps

    International Nuclear Information System (INIS)

    The staffing requirements of the nuclear electric utility industry will create very large demands in the next 3 years for nuclear trained personnel in operation and maintenance. The commercial nuclear industry recognizes these needs, the importance of having qualified trained personnel, and is taking appropriate action to satisfy these requirements. The education and training capabilities both inside and outside of the utility industry have the capacity to meet these demands if they are properly managed. In particular, the Institute of Nuclear Power Operations Human Resource Management System provides a framework for an organized industry-wide program. The Nuclear Regulatory Commission's Office of Inspection and Enforcement is in effect a Federal Corps focused on nuclear operations. Its Reactor Training Center trains the professionals required to inspect nuclear operations and enforce regulations. Therefore, the Department of Energy (DOE) believes that the objectives of a Federal Nuclear Operations Corps can be met by existing private and Federal efforts and that there is no need to establish another corps or training academy. This is consistent with the Administration's policy of minimizing the Federal role in areas where the private sector is capable

  2. Theoretical studies in nuclear reactions and nuclear structure

    International Nuclear Information System (INIS)

    During the past year, research in theoretical nuclear physics at the University of Maryland attained a number of exciting and important results. These are described in some detail throughout the report, but some of the highlights are as follows: large Nc QCD has been shown to place strong constraints on vacuum effects of hadronic field theories; color dielectric models of hadrons have been understood in terms of lattice QCD; we have completed a relativistic analysis of proton scattering to test virtual pair contributions; we have also re-derived the Mandelzweig-Wallace two-body Dirac equation in covariant form, and applied it to the atomic two-body bound states: hydrogen, muonium and positronium; we have carried out the first calculation of the triton binding energy with a realistic quark-based nucleon-nucleon interaction and have learned that new kinds of nonlocalities in the tensor force may produce unexpected results; and we have shown that the Quadronium Conjecture can lead to spontaneous creation of the atom with low momentum as required by the observations, and are constructing a model to quantify the Quadronium phenomenology of the e+e- Puzzle

  3. CAVERNOUS HEMANGIOMA OF THE INTERNAL AUDITORY CANAL

    Directory of Open Access Journals (Sweden)

    Mohammad Hossein Hekmatara

    1993-06-01

    Full Text Available Cavernous hemangioma is a rare benign tumor of the internal auditory canal (IAC of which fourteen cases have been reported so far."nTinnitus and progressive sensorineural hearing loss (SNHL are the chief complaints of the patients. Audiological and radiological planes, CTScan, and magnetic resonance image (MRI studies are helpful in diagnosis. The only choice of treatment is surgery with elective transmastoid trans¬labyrinthine approach. And if tumor is very large, the method of choice will be retrosigmoid approach.

  4. Nuclear microprobe applications to biomedical studies

    International Nuclear Information System (INIS)

    Nuclear Microprobe techniques have a remarkable potential in biomedicine once image information on tissue topography, structural organisation and elemental distribution is simultaneously obtained. These micro-analytical techniques can constitute an important tool for studies of the influence of external aggressors in health, such as internalised airborne particulate matter, and in pathological conditions associated to inflammatory processes that may result from endogenous aggressors (e.g., reactive products of metabolism, essential trace elements impairment). The tissue reactivity to exogenous or endogenous toxic substances may involve remodelling of specific cells organisation, such as epithelial layers or basement membranes. The evaluation of the magnitude of tissue remodelling and its progression is of the foremost importance to assess the mechanisms involved. The fate of respired particles in the human respiratory system and the evaluation of skin alterations in haemochromatosis condition (disease characterised by impaired Fe metabolism) will illustrate some of the helpful aspects of NMP in biomedical studies. The chemical characterisation of individual particles in the epithelial regions of trachea and bronchi, the accumulation of toxic elements, such as V, Cr, and Ni, in lung alveoli and their mobilisation to surrounding tissue, to phagocytic cells and to the associated lymphatic tissue will be discussed. Also, the abnormal deposition of Fe and its possible role in skin inflammation an din changes of skin integrity and structure will also be presented

  5. Progress report on nuclear spectroscopic studies

    Energy Technology Data Exchange (ETDEWEB)

    Bingham, C.R.; Riedinger, L.L.; Sorensen, S.P.

    1996-01-16

    The experimental program in nuclear physics at the University of Tennessee, Knoxville, is led by Professors Carrol Bingham, Lee Riedinger, and Soren Sorenseni who respectively lead the studies of the exotic decay modes of nuclei far from stability, the program of high-spin research, and our effort in relativistic heavy-ion physics. Over the years, this broad program of research has been successful partially because of the shared University resources applied to this group effort. The proximity of the Oak Ridge National Laboratory has allowed us to build extremely strong programs of joint research, and in addition to play an important leadership role in the Joint Institute for Heavy Ion Research (JIHIR). Our experimental program is also very closely linked with those at other national laboratories: Argonne (collaborations involving the Fragment Mass Analyzer (FMA) and {gamma}-ray arrays), Brookhaven (the RHIC and Phenix projects), and Berkeley (GAMMASPHERE). We have worked closely with a variety of university groups in the last three years, especially those in the UNISOR and now UNIRIB collaborations. And, in all aspects of our program, we have maintained close collaborations with theorists, both to inspire the most exciting experiments to perform and to extract the pertinent physics from the results. The specific areas discussed in this report are: properties of high-spin states; study of low-energy levels of nuclei far from stability; and high energy heavy-ion physics.

  6. Nuclear analytical techniques for nanotoxicology studies

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Z.Y.; Zhao, Y.L.; Chai, Z.F. [Chinese Academy of Sciences, Beijing (China). Key Lab for Biomedical Effects of Nanomaterials and Nanosafety

    2011-07-01

    With the rapid development of nanotechnology and its applications, a wide variety of nanomaterials are now used in commodities, pharmaceutics, cosmetics, biomedical products, and industries. The potential interactions of nanomaterials with living systems and the environment have attracted increasing attention from the public, as well as from manufacturers of nanomaterial-based products, academic researchers and policymakers. It is important to consider the environmental, health and safety aspects at an early stage of nanomaterial development and application in order to more effectively identify and manage potential human and environmental health impacts from nanomaterial exposure. This will require research in a range of areas, including detection and characterization, environmental fate and transport, ecotoxicology and toxicology. Nuclear analytical techniques (NATs) can play an important role in such studies due to their intrinsic merits such as high sensitivity, good accuracy, high space resolution, ability to distinguish the endogenous or exogenous sources of materials, and ability of in situ and in vivo analysis. In this paper, the applications of NATs in nanotoxicological and nano-ecotoxicological studies are outlined, and some recent results obtained in our laboratory are reported. (orig.)

  7. Nuclear analytical techniques for nanotoxicology studies

    International Nuclear Information System (INIS)

    With the rapid development of nanotechnology and its applications, a wide variety of nanomaterials are now used in commodities, pharmaceutics, cosmetics, biomedical products, and industries. The potential interactions of nanomaterials with living systems and the environment have attracted increasing attention from the public, as well as from manufacturers of nanomaterial-based products, academic researchers and policymakers. It is important to consider the environmental, health and safety aspects at an early stage of nanomaterial development and application in order to more effectively identify and manage potential human and environmental health impacts from nanomaterial exposure. This will require research in a range of areas, including detection and characterization, environmental fate and transport, ecotoxicology and toxicology. Nuclear analytical techniques (NATs) can play an important role in such studies due to their intrinsic merits such as high sensitivity, good accuracy, high space resolution, ability to distinguish the endogenous or exogenous sources of materials, and ability of in situ and in vivo analysis. In this paper, the applications of NATs in nanotoxicological and nano-ecotoxicological studies are outlined, and some recent results obtained in our laboratory are reported. (orig.)

  8. Progress report on nuclear spectroscopic studies

    International Nuclear Information System (INIS)

    The experimental program in nuclear physics at the University of Tennessee, Knoxville, is led by Professors Carrol Bingham, Lee Riedinger, and Soren Sorenseni who respectively lead the studies of the exotic decay modes of nuclei far from stability, the program of high-spin research, and our effort in relativistic heavy-ion physics. Over the years, this broad program of research has been successful partially because of the shared University resources applied to this group effort. The proximity of the Oak Ridge National Laboratory has allowed us to build extremely strong programs of joint research, and in addition to play an important leadership role in the Joint Institute for Heavy Ion Research (JIHIR). Our experimental program is also very closely linked with those at other national laboratories: Argonne (collaborations involving the Fragment Mass Analyzer (FMA) and γ-ray arrays), Brookhaven (the RHIC and Phenix projects), and Berkeley (GAMMASPHERE). We have worked closely with a variety of university groups in the last three years, especially those in the UNISOR and now UNIRIB collaborations. And, in all aspects of our program, we have maintained close collaborations with theorists, both to inspire the most exciting experiments to perform and to extract the pertinent physics from the results. The specific areas discussed in this report are: properties of high-spin states; study of low-energy levels of nuclei far from stability; and high energy heavy-ion physics

  9. Nuclear legislation. Analytical study: regulatory and institutional framework for nuclear activities

    International Nuclear Information System (INIS)

    This study is part of the series of analytical studies of the major aspects of nuclear legislation in OECD Member countries, prepared by the OECD Nuclear Energy Agency (NEA) with the co-operation of the appropriate services of countries concerned. The first study, published in 1967, dealt with national legislations concerning nuclear third party liability. Since then, several studies on other aspects of nuclear law (e.g., transport, radiation protection, trade, etc) in Member countries have been issued. Each study is based, to the extent possible, on a standardised plan of all countries, allowing an easier retrieval and comparison of the information contained. Periodical updates are also issued in order to help the reader keep abreast of amendments in national nuclear laws and regulations, such s the revision of the study on nuclear third party liability, in 1990. The reader will find a revised and expanded version of the 1983-1984 study reflecting new changes in nuclear law and encompassing new Member countries to the OECD since then. This new version reviews the body of regulations governing nuclear activities in the OECD area as well as the institutional framework in which such regulations are applied in each country. This study is based on information available to the NEA Secretariat as of May 1995, and neither the Secretariat nor national authorities concerned assume any liability for it. It is published under the responsibility of the Secretary-General of the OECD. (author)

  10. Reduction of Enterococcus faecalis in curved root canals after various sizes and tapers of canal preparation

    Directory of Open Access Journals (Sweden)

    Amir Abbas Moshari

    2015-01-01

    Full Text Available Aims: The aim of this study was to evaluate the reduction of Enterococcus faecalis in curved root canals after various sizes and tapers of the canal preparation. Materials and Methods: Mandibular first molars (n = 103 with curved mesiobuccal canals were divided into one control (n = 5 and 7 experimental (n = 14 groups, were inoculated with E. faecalis (ATTC 29212 and prepared with the following RaCe files (FKG Dentaire as master apical file: Groups: 25.04, 25.06, 30.04, 30.06, 35.04, 35.06 and 40.06. All the experimental groups were irrigated with 2 mL of 1% sodium hypochlorite during instrumentation and finally rinsed with 17% ethylenediaminetetraacetic acid (EDTA (2 mL followed by 5.25% NaOCl (2 mL and sterile distilled water. Colony counting was performed after incubation. Statistical Analysis Used: Resulting data were analyzed using one-way ANOVA and Tukey′s post-hoc test, (P < 0.05. Results and Conclusions: All the experimental groups showed significant bacterial reduction (P < 0.001. Although the greater the size/taper or both led to more decreased amount of bacteria, differences between the groups with the identical size and different tapers, and among the groups with the same taper and different sizes were not significant. Based on this study, 25.04 along with using 2 mL of 1% NaOCl during instrumentation, and using 17% EDTA and 5.25% NaOCl as final rinse successively after the termination of preparation, can effectively reduce intra-canal bacteria and preserve root structure.

  11. Micro-Machined Flow Sensors Mimicking Lateral Line Canal Neuromasts

    Directory of Open Access Journals (Sweden)

    Hendrik Herzog

    2015-08-01

    Full Text Available Fish sense water motions with their lateral line. The lateral line is a sensory system that contains up to several thousand mechanoreceptors, called neuromasts. Neuromasts occur freestanding on the skin and in subepidermal canals. We developed arrays of flow sensors based on lateral line canal neuromasts using a biomimetic approach. Each flow sensor was equipped with a PDMS (polydimethylsiloxane lamella integrated into a canal system by means of thick- and thin-film technology. Our artificial lateral line system can estimate bulk flow velocity from the spatio-temporal propagation of flow fluctuations. Based on the modular sensor design, we were able to detect flow rates in an industrial application of tap water flow metering. Our sensory system withstood water pressures of up to six bar. We used finite element modeling to study the fluid flow inside the canal system and how this flow depends on canal dimensions. In a second set of experiments, we separated the flow sensors from the main stream by means of a flexible membrane. Nevertheless, these biomimetic neuromasts were still able to sense flow fluctuations. Fluid separation is a prerequisite for flow measurements in medical and pharmaceutical applications.

  12. RVG数字成像系统用于离体牙根管工作长度测量的研究%A study of root canal working length measurement of extracted teeth on radio visio graphy.

    Institute of Scientific and Technical Information of China (English)

    余小伟; 朱友家; 卢爽

    2011-01-01

    目的:研究 RVG(Radio Visio Graphy)数字成像系统测量根管工作长度的准确性,为临床应用提供参考依据.方法:收集离体牙 150 颗,其中前牙 40 颗、前磨牙 60 颗、磨牙 50 颗,采用改良双敞技术根管预备后,插入根管锉,保持根管锉尖与根尖孔齐平.模拟 X 线平行投照技术拍摄 RVG 数字图像,利用配套的测量软件进行校正处理后测量根管工作长度.再用电子游标卡尺测得根管锉插入根管的实际长度:两种方法测量结果使用 SPSS 17.0 软件进行统计分析.结果:前牙、前磨牙 RVG 数字系统测量值十分接近真实值(P>0.05);磨牙 RVG 数字系统测量值较真实值大(P0.85).结论:RVG 数字成像系统对临床测量根管工作长度有一定指导意义.%Objective: TO evaluate the accuracy of root canal working length measurement on radio visio graphy, in order to provide reference date for the clinical application.Method: According to experimental standard, The 150 extracted teeth were collected in this study,40 anterior teeth,60 premolars and 50 molars.After root canals were treated with modified double-flared technique,put the file in the root canals,ensured the tip of files reached the apical foramens.Imitated X-ray parallel technique,the length of root canels were measured in the RVG digital images with the software.And compared with the actual length of files through the SPSS 17.0 software.Result: The difference of anterior teeth and premolars between the two goups of measurments had no statistical significance (P >0.05); however, the difference of molars was accepted as significant but rc>0.85.Conclusion: Radio Visio Graphy should be valuable in the measurement of root canal working length.

  13. Application of Tritium Tracer to Canal Seepage Measurements

    International Nuclear Information System (INIS)

    The paper considers the problem of seepage loss from water carrier and storage systems and the application of tritiated water to the detection and measurement of such losses. A field study of seepage loss from an 800 ft reach of the Madera Canal, located in the San Joaquin Valley of California, was made. Tritiated water was employed to measure the progress of underground seepage from the canal and the loss of water from an isolated reach of the canal. Velocities of ground water flow were also determined by the point-dilution technique with both chloride and tritium tracers. Laboratory studies of the point-dilution method were conducted for determination of its theoretical validity under controlled conditions and for comparison of the relative efficacies of chloride and tritium. (author)

  14. Improved Visualization of Cartilage Canals Using Quantitative Susceptibility Mapping.

    Directory of Open Access Journals (Sweden)

    Mikko J Nissi

    Full Text Available Cartilage canal vessels are critical to the normal function of epiphyseal (growth cartilage and damage to these vessels is demonstrated or suspected in several important developmental orthopaedic diseases. High-resolution, three-dimensional (3-D visualization of cartilage canals has recently been demonstrated using susceptibility weighted imaging (SWI. In the present study, a quantitative susceptibility mapping (QSM approach is evaluated for 3-D visualization of the cartilage canals. It is hypothesized that QSM post-processing improves visualization of the cartilage canals by resolving artifacts present in the standard SWI post-processing while retaining sensitivity to the cartilage canals.Ex vivo distal femoral specimens from 3- and 8-week-old piglets and a 1-month-old human cadaver were scanned at 9.4 T with a 3-D gradient recalled echo sequence suitable for SWI and QSM post-processing. The human specimen and the stifle joint of a live, 3-week-old piglet also were scanned at 7.0 T. Datasets were processed using the standard SWI method and truncated k-space division QSM approach. To compare the post-processing methods, minimum/maximum intensity projections and 3-D reconstructions of the processed datasets were generated and evaluated.Cartilage canals were successfully visualized using both SWI and QSM approaches. The artifactual splitting of the cartilage canals that occurs due to the dipolar phase, which was present in the SWI post-processed data, was eliminated by the QSM approach. Thus, orientation-independent visualization and better localization of the cartilage canals was achieved with the QSM approach. Combination of GRE with a mask based on QSM data further improved visualization.Improved and artifact-free 3-D visualization of the cartilage canals was demonstrated by QSM processing of the data, especially by utilizing susceptibility data as an enhancing mask. Utilizing tissue-inherent contrast, this method allows noninvasive assessment

  15. Forced extrusion for removal of impacted third molars close to the mandibular canal Extrusión forzada para extraer los terceros molares impactados cerca del canal mandibular

    Directory of Open Access Journals (Sweden)

    Dennis Flanagan DDS

    2012-03-01

    Full Text Available Impacted mandibular third molars can be located in close proximity to the mandibular canal. This creates a risk for the nerve or artery injury. These are contained in the canal. However, the impacted third molar can be moved coronally by orthodontic means, after removal of overlying bone, and safely extracted. The orthodontic intervention slowly moves the tooth apex away from the mandibular canal and reduces the potential for a neural injury. This method may be useful for older patients with root apices that approximate or are actually located in the mandibular canal. This technique needs further study. There is a theoretical potential for neural or arterial injury from physical contact of the tooth apex as it moves by or through the mandibular canal.Los terceros molares inferiores impactados pueden localizarse muy cerca del canal mandibular. Esto constituye un riesgo de lesión del nervio o la arteria, que se localizan dentro del canal. No obstante, el tercer molar impactado puede desplazarse en dirección coronal con ortodoncia, tras ostectomía del hueso suprayacente, y extraerse sin riesgos. La intervención ortodóncica desplaza lentamente el ápice del diente fuera del canal mandibular y reduce la posibilidad de lesión neural. Este método puede ser útil para pacientes de edad avanzada con ápices dentales que se aproximan o en realidad se localizan en el canal mandibular. La técnica necesita un estudio adicional. Hay la posibilidad teórica de lesión neural o arterial a partir del contacto físico del ápice del diente a medida que se desplaza a través del canal mandibular.

  16. Evaluation of Clinical Findings and Treatment Results in Patients With Lumber Spinal Canal Stenosis and Osteoporosis Treated With Calcitonin and Physical Therapy

    OpenAIRE

    Hidayet Sarı; Ülkü Akarırmak; A. Akkan; D. Onel

    2002-01-01

    Objective: The role of osteoporosis in the etiology of degenerative lumbar spinal canal stenosis is debatable. The aim of this study was to evaluate clinic as well as therapeutic results in subjects with osteoporosis combined with lumbar spinal canal stenosis (LSS). Material and Methods: The study was conducted in İ.Ü. Cerrahpaşa Medical Faculty PMR Department on 40 patients diagnosed as spinal canal stenosis . Lumbar canal was imaged by computerized tomography (CT). Bone mineral content (...

  17. Comparison of root canal lathing measurement by conventional and digital radiology

    International Nuclear Information System (INIS)

    A correct working length is a critical factor within the endodontic treatment. The length of the root canal can be measured by different methods. The aim of this study was to compare methods used for measuring the length of root canals using conventional and digital radiology. The measurement was provided in both - in vitro and in vivo conditions. (authors)

  18. Effect of needle insertion depth and root canal curvature on irrigant extrusion ex vivo

    NARCIS (Netherlands)

    Psimma, Z.; Boutsioukis, C.; Kastrinakis, E.; Vasiliadis, L.

    2013-01-01

    Introduction The aim of this study was to evaluate the effect of needle type and insertion depth, apical preparation size, and root canal curvature on irrigant extrusion by using a recently introduced method. Methods Sixteen human teeth with a straight root canal (group A) and 16 with a moderatel

  19. Nuclear structure studies of F-24

    Czech Academy of Sciences Publication Activity Database

    Caceres, L.; Lepailleur, A.; Sorlin, O.; Stanoiu, M.; Grévy, S.; Mrázek, Jaromír; Negoita, F.; Oliveira de Santos, F.; Penionzhkevich, Y. E.; Rotaru, F.

    2015-01-01

    Roč. 92, č. 1 (2015), 014327. ISSN 0556-2813 Institutional support: RVO:61389005 Keywords : spectrometer * GANIL * forces Subject RIV: BG - Nuclear , Atomic and Molecular Physics, Colliders Impact factor: 3.733, year: 2014

  20. Nuclear magnetic resonance studies of metabolic regulation

    International Nuclear Information System (INIS)

    Nuclear magnetic resonance (NMR) techniques for the detection of the metabolic transformations of biological compounds labeled with stable isotopes, particularly carbon-13 have been explored. We have studied adipose tissue in the intact rat, the exteriorized epididymal fat pad, and the isolated adipocyte. Triacylglycerol metabolism in adipose tissue is regulated by lipogenic factors (insulin, corticosterone, thyroxine, and growth hormone) and lipolytic factors (glucagon and catecholamines). The synthesis of triglyceride from 5.5 mM glucose was stimulated by about 4-fold by 10 nM insulin. Triglyceride synthesis from glucose in the presence of insulin occurred at a rate of 330 nmol/hr/106 cells. Since the NMR signals from free and esterified fatty acids and glycerol are distinct, we could directly measure the rate of hormone-stimulated lipolysis. Epinephrine (10 μM) gave a lipolytic rate of 0.30 μmol/hr/106 cells as monitored by free-glycerol appearance in the medium. 13C NMR provides a superior method for the measurement of triglyceride metabolism since it directly measures the changes in the substrates and products in situ

  1. Study of nuclear fuel burn-up

    International Nuclear Information System (INIS)

    The authors approach theoretical treatment of isotopic composition changement for nuclear fuel in nuclear reactors. They show the difficulty of exhaustive treatment of burn-up problems and introduce the principal simplifying principles. Due to these principles they write and solve analytically the evolution equations of the concentration for the principal nuclides both in the case of fast and thermal reactors. Finally, they expose and comment the results obtained in the case of a power fast reactor. (author)

  2. Theoretical studies in hadronic and nuclear physics

    International Nuclear Information System (INIS)

    Research in the Maryland Nuclear Theory Group focusses on problems in four basic areas of current relevance. The section on Hadrons in Nuclei reports research into the ways in which the properties of nucleons and the mesons which play a role in the nuclear force are modified in the nuclear medium. QCD sum rules supply a new insight into the decrease of the nucleon's mass in the nuclear medium. The quark condensate decreases in nuclear matter, and this is responsible for the decrease of the nucleon's mass. The section on the Structure of Hadrons reports progress in understanding the structure of the nucleon. These results cover widely different approaches -- lattice gauge calculations, QCD sum rules, quark-meson models with confinement and other hedgehog models. Progress in Relativistic Nuclear Physics is reported on electromagnetic interactions in a relativistic bound state formalism, with applications to elastic electron scattering by deuterium, and on application of a two-body quasipotential equation to calculate the spectrum of mesons formed as bound states of a quark and antiquark. A Lorentz-invariant description of the nuclear force suggests a decrease of the nucleon's mass in the nuclear medium similar to that found from QCD sum rules. Calculations of three-body bound states with simple forms of relativistic dynamics are also discussed. The section on Heavy Ion Dynamics and Related Processes describes progress on the (e+e-) problem and heavy-on dynamics. In particular, the sharp electrons observed in β+ irradiation of heavy atoms have recently been subsumed into the ''Composite Particle Scenario,'' generalizing the ''(e+e--Puzzle'' of the pairs from heavy ion collisions to the ''Sharp Lepton Problem.''

  3. Nuclear Image Analysis Study of Neuroendocrine Tumors

    OpenAIRE

    Park, Meeja; Baek, Taehwa; Baek, Jongho; Son, Hyunjin; Kang, Dongwook; Kim, Jooheon; Lee, Hyekyung

    2012-01-01

    Background There is a subjective disagreement about nuclear chromatin in the field of pathology. Objective values of red, green, and blue (RGB) light intensities for nuclear chromatin can be obtained through a quantitative analysis using digital images. Methods We examined 10 cases of well differentiated neuroendocrine tumors of the rectum, small cell lung carcinomas, and moderately differentiated squamous cell lung carcinomas respectively. For each case, we selected 30 representative cells a...

  4. Evolution of canals system linking the Vistula, Dnieper and Neman basins

    Science.gov (United States)

    Brykala, Dariusz; Badziai, Vitali

    2014-05-01

    The aim of this study is to reconstruct landscape changes in the Polesie Region - one of the largest European swampy areas (Belarus), as a result of the creation and operation of a network of canals. From the 16th century efforts were undertaken to connect the Polish areas located in the drainage basins of the Black Sea and Baltic Sea with canals. Already in 1631 the Polish Sejm (parliament) approved the project to build a canal linking the River Berezina (Dnieper basin) with the River Neris (Neman basin). However, the complicated political and economic situation of the country did not allow doing this. Only in the second half of the 18th c. hetman Ogiński financed the construction of a canal linking the Dnieper and Neman basins. The canal connecting the River Szczara (Neman basin) with the River Jasiołda (Pripyat basin) was named after its creator - the Ogiński Canal. At the same time the construction of the Królewski (Royal) Canal linking the River Muchavets (Vistula basin) and the River Pina (Pripyat basin) was under way. The construction of the canal was completed in 1783. The winding channels of the Pina and Muchavets were straightened, and the numerous canals feeding the waterway system drained vast area of marshes and wetlands of the Polesia Region. The last element that connects the catchments of the Vistula and Neman is the Augustów Canal built in the years 1825-1839 (linking the catchments of the Biebrza and Neman). Numerous changes in political boundaries in the watershed area between the Black Sea and the Baltic Sea drainage basins caused the destruction of the hydraulic structures. All the analysed canals were completely destroyed during the two world wars. In the last 200 years the amount and type of locks and weirs has changed. For example, there were no weirs on the Royal Canal in the late 18th c., in the middle of the 19th c. there were 22 such structures, while now that number has gone down to 10. All canals were created for economic reasons

  5. Scalloping at the lumbosacral canal

    Energy Technology Data Exchange (ETDEWEB)

    Reinhardt, R.

    1987-07-01

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

  6. Scalloping at the lumbosacral canal

    International Nuclear Information System (INIS)

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

  7. Contemporary root canal filling strategies

    OpenAIRE

    Moinzadeh, A.T.

    2016-01-01

    Currently, clinicians can choose from a wide range of root canal filling materials and techniques, some of which have been evaluated in this thesis. Methacrylate resin-based sealers suffer from polymerization shrinkage stresses. This limitation may partly be overcome by a two-step cementation procedure. This alternative placement technique results in an increase and homogenization of the adhesion of the material to intraradicular dentin. Subsequent research should aim at developing sealers wi...

  8. Nuclear wasteform materials: Atomistic simulation case studies

    Energy Technology Data Exchange (ETDEWEB)

    Chroneos, A., E-mail: alex.chroneos@open.ac.uk [Materials Engineering, The Open University, Milton Keynes MK7 6AA (United Kingdom); Department of Materials, Imperial College London, London SW7 2AZ (United Kingdom); Institute of Materials Science, NCSR Demokritos, GR-15310 Athens (Greece); Rushton, M.J.D. [Department of Materials, Imperial College London, London SW7 2AZ (United Kingdom); Jiang, C. [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); Tsoukalas, L.H. [Department of Nuclear Engineering, Purdue University, West Lafayette, IN 47907 (United States)

    2013-10-15

    Ever increasing global energy demand combined with a requirement to reduce CO{sub 2} emissions has rekindled an interest in nuclear power generation. In order that nuclear energy remains publicly acceptable and therefore a sustainable source of power it is important that nuclear waste is dealt with in a responsible manner. To achieve this, improved materials for the long-term immobilisation of waste should be developed. The extreme conditions experienced by nuclear wasteforms necessitate the detailed understanding of their properties and the mechanisms acting within them at the atomic scale. This latter issue is the focus of the present review. Atomic scale simulation techniques can accelerate the development of new materials for nuclear wasteform applications and provide detailed information on their physical properties that cannot be easily accessed by experiment. The present article introduces examples of how atomic scale, computational modelling techniques have led to an improved understanding of current nuclear wasteform materials and also suggest how they may be used in the development of new wasteforms.

  9. Direct digital radiography versus conventional radiography for estimation of canal length in curved canals

    Energy Technology Data Exchange (ETDEWEB)

    Mohtavipour, Seiedeh Tahereh; Dalili, Zahra; Azar, Nasim Gheshlaghi [Faculty of Dentistry, Guilan University of Medical Sciences, Guilan (Iran, Islamic Republic of)

    2011-03-15

    The purpose of this study was to compare the conventional and digital radiography in the estimation of working length in mandibular molars. Sixty molar teeth were selected and divided into three groups in the basis of canal curves (0-15 degree, 15-30 degree, >30 degree). After the placement of a 15 K-file, radiographs were taken with a conventional film (F-speed) and a digital sensor. Canal lengths were measured in these images by two observers. Statistical analysis was performed with repeated measures of ANOVA and paired sample t-test with 95% confidence. There was a high inter-observer agreement on the measurements of working length in conventional and digital radiographs. There was no significant difference between the mean values of measurements in conventional and digital radiography. Moreover, there was no significant difference between conventional and digital radiography with the actual values in the basis of canal curves. The accuracy of conventional and digital radiography in the determination of the working length was in an acceptable range.

  10. Direct digital radiography versus conventional radiography for estimation of canal length in curved canals

    International Nuclear Information System (INIS)

    The purpose of this study was to compare the conventional and digital radiography in the estimation of working length in mandibular molars. Sixty molar teeth were selected and divided into three groups in the basis of canal curves (0-15 degree, 15-30 degree, >30 degree). After the placement of a 15 K-file, radiographs were taken with a conventional film (F-speed) and a digital sensor. Canal lengths were measured in these images by two observers. Statistical analysis was performed with repeated measures of ANOVA and paired sample t-test with 95% confidence. There was a high inter-observer agreement on the measurements of working length in conventional and digital radiographs. There was no significant difference between the mean values of measurements in conventional and digital radiography. Moreover, there was no significant difference between conventional and digital radiography with the actual values in the basis of canal curves. The accuracy of conventional and digital radiography in the determination of the working length was in an acceptable range.

  11. Analysis Study on the News Media Report of Nuclear Events

    International Nuclear Information System (INIS)

    competitiveness. Those relations are very important to survive in this planet as a powered country. So, the ROK should be at the head of countries in the energy problem. But, the nuclear industry in Korea is effected by public media. On this study, I would like to study the way of newspapers report about nuclear issues. This paper could offer journalists recommendations on how to improve their skills in reporting issues related to the nuclear industry. I would like to introduce better ways of informing the press and public of the benefits and safety of the nuclear industry

  12. A comparative study of European nuclear energy programs

    Energy Technology Data Exchange (ETDEWEB)

    Presas i Puig, Albert (ed.)

    2011-07-01

    The report includes the following contributions: Comparative study of European Nuclear Energy Programs. From international cooperation to the failure of a national program: the Austrian case. The ''go-and-stop'' of the Italian civil nuclear programs, among improvisations, ambitions and conspiracy. Nuclear energy in Spain - a research agenda for economic historians. The Portuguese nuclear program: a peripheral experience under dictatorship (1945-1973). The nuclear energy programs in Switzerland. The rise and decline of an independent nuclear power industry in Sweden, 1945-1970. The German fast breeder program, a historical review. Fast reactors as future visions - the case of Sweden. Transnational flows of nuclear knowledge between the U.S. and the U.K. and continental Europe in the 1950/60s. The Carter administration and its non-proliferation policies: the road to INFCE.

  13. Study of nuclear environment and material strategy

    International Nuclear Information System (INIS)

    There is a concern about the environmental hazard caused by radioactive materials coming with the expansion of nuclear power and even by renewable energies, which are used as countermeasures against global warming to construct a sustainable society. A concept to internalize the pollution caused by radioactive materials, which are directly or indirectly related to nuclear power, to economical activities by adopting externality is proposed. Energy and industrial productions are strongly related to the supply of material. Therefore material flow is also part of this internalization concept. The concept is named 'NEMS (Nuclear Environment and Material Strategy)'. Fission products and transuranic isotopes from nuclear power such as plutonium are considered in this concept. Thorium, which comes from the material flow of rare-earth production to support the elaboration of renewable energies including electric vehicles on the consumer side, is considered as an externality of the non-nuclear power field. Fission products contain some rare-earth materials. Thus, these rare-earth materials, which are extracted by the advanced ORIENT (Optimization by Recycling Instructive Elements) cycle, are internalized as rare-earth supplier in economy. However, the supply quantity is limited. Therefore rare-earth production itself is still needed. The externality of rare-earth production is thorium and is internalized by using it as nuclear fuel. In this case, the demand of thorium is still small within these few decades compared to the production of thorium as byproduct of the rare-earth production. A thorium energy bank (The Bank) is advanced to regulate the storage of the excess amount of thorium inside of an international framework in order to prevent environmental hazard resulting from the illegal disposal of thorium. In this paper, the material flows of thorium and rare-earth are outlined. Their material balance are demonstrated based on the prediction of rare-earth mining and an

  14. Feasibility study for the Nuclear Research Centre of the Nuclear Energy Commission

    International Nuclear Information System (INIS)

    The feasibility study was carried out in order to evaluate the possibility of building a Nuclear Research Centre in Uruguay, which would support a wide range of nuclear related technological activities. A market research was carried out, of the products to be manufactured at the Nuclear Centre, regarding the size of production. A detailed list of the main products considered is enclosed. The siting study was performed through the analysis of the incidental factors, such as environment, technical scope and socio-ecomonic factors. An engineering study for the main installations was done. The investment and financial sources were also studied

  15. 单根管与多根管铸造桩核用于磨牙残冠修复的比较研究%Comparative study of defected molar restored by cast post-core in single root canal or multiple root canals

    Institute of Scientific and Technical Information of China (English)

    赵倩; 周源; 王左敏

    2012-01-01

    目的 比较单根管与多根管铸造桩核冠修复磨牙残冠的临床效果.方法 选择140例患者的153颗磨牙残冠,在修复前行完善的根管治疗,其中92颗采用单根管整体铸造桩核冠修复,61颗采用插销式铸造的多根管桩核冠修复.对修复后两年的复查结果进行临床效果评价.结果 单根管固位修复体桩核松动1个,其余桩核X线片显示桩核与根管结合紧密,修复效果良好.多根管分体插销式铸造桩核冠无松动.修复的临床效果无显著性差异(P>0.05).结论 采用单根管铸造桩核修复磨牙残冠不仅制作简单,而且与多根管分体桩核修复无显著性差异,同样可取得良好的临床效果.%Objective To compare the clinical effects of defected molar restored by cast post-core in single root canal or multiple root canals. Methods Selected 153 residual crown or root molars of 140 patients which had been made complete root canal treatment, including 92 teeth restored by a whole cast post-core crowns in single-root canal, 61 restored by bolt cast post-core crowns in multiple root canals. Reviewed the results of the clinical effects after two years of restoration. Results We discovered movement in one tooth which be fixed by single root canal post-core crown, and observed that other teeth did not move and had a close integration with the root canals.Teeth restored by bolt cast post-core crowns in multiple root canals had no movement. The clinical effects of repair had no significant difference (P>0.05). Conclusion It is well simple way that using cast post-core crown in single-root canal to restore defected molar.It has no significant difference with multiple root canal post-core.The same can be achieved good clinical effects.

  16. Optodynamic Phenomena During Laser-Activated Irrigation Within Root Canals

    Science.gov (United States)

    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.

  17. Lightlike Hypersurfaces and Canal Hypersurfaces of Lorentzian Surfaces

    Directory of Open Access Journals (Sweden)

    Jianguo Sun

    2014-01-01

    Full Text Available The lightlike hypersurfaces in semi-Euclidean space are of special interest in Relativity Theory. In particular, the singularities of these lightlike hypersurfaces provide good models for the study of different horizon types. And we obtain some geometrical propositions of the canal hypersurfaces of Lorentzian surfaces. We introduce the notions of flatness for these hypersurfaces and study their singularities.

  18. Complex radiodiagnosis of the lumbar spine spinal canal stenosis

    International Nuclear Information System (INIS)

    Ultrasound study was done in 67 patients with osteochondrosis of the lumbar spine revealed by x-ray study, magnetic resonance imaging and computed tomography. Ultrasound technique is highly informative in visualizing location, direction, size of the hernia in lumbar osteochondrosis and stenosis of spinal canal

  19. Visibility of the central canal on MRI

    Energy Technology Data Exchange (ETDEWEB)

    Petit-Lacour, M.C.; Lasjaunias, P.; Iffenecker, C.; Benoudiba, F.; Hadj Rabia, M.; Doyon, D. [Service de Neuroradiologie, Faculte de Paris Sud (France); Hurth, M. [Department of Neurosurgery, Faculte Paris Sud, Kremlin-Bicetre (France)

    2000-10-01

    The central canal of the spinal cord is present at birth and becomes progressively obliterated. Cadaver studies have shown that it may persiste partially or completely. To our knowledge, this entity has not been described on MRI. We reviewed 794 MRI studies of the spinal cord, and found 12 patients (aged 14 to 65 years) who had an intramedullary cavity. The cavity was at the junction of the ventral {sup 1}/{sub 3} and dorsal {sup 2}/{sub 3} of the spinal cord, except at the level of the lumbar enlargement, where it was central. It was filiform in most cases, although sometimes fusiform (3 to 4 mm in diameter), and had regular contours. The cavity were thoracic in 69 % of cases. The clinical features were totally unrelated to the image, and there were no anatomical factors (Chiari malformation, dysraphism) predisposing to syringomyelia. The images were perfectly compatible with a persistent central canal, which we interpret as a variant of normal anatomy. Therefore it is important to regard these findings as normal, to avoid unnecessary treatment and follow-up. (orig.)

  20. Nuclear weapons and NATO operations: Doctrine, studies, and exercises

    International Nuclear Information System (INIS)

    A listing of papers is presented on the doctrine, studies, and exercises dealing with nuclear weapons and NATO operations for the period 1950-1983. The papers deal with studies on massive retaliation, sword and shield, and flexible response. Some of the enduring issues of nuclear weapons in NATO are listed

  1. A study on the globalization of nuclear development

    International Nuclear Information System (INIS)

    Nuclear power technology in Korea has been reached at about 95 % level to self-reliance, which has developed energetically since mid of 1980s. Nowadays, it is required to set up globalization of nuclear policy to ensure the introduction of more advanced technologies and to enlarge the use of their developed technologies. In this study, prospects of nuclear power and wastes management, international safeguards, and international co-operation were analyzed focusing on the International Atomic Energy Agency to support timely the introduction of advanced technologies and assure international nuclear communities of Korean nuclear transparency in order to enhance the national policy for self-reliance on their future technology development. This study can be applied to the efficient implementation of Korean nuclear development policy and globalization policy as well. 3 tabs., 1 fig., 13 refs. (Author)

  2. Nuclear Criticality Technology and Safety Project parameter study database

    International Nuclear Information System (INIS)

    A computerized, knowledge-screened, comprehensive database of the nuclear criticality safety documentation has been assembled as part of the Nuclear Criticality Technology and Safety (NCTS) Project. The database is focused on nuclear criticality parameter studies. The database has been computerized using dBASE III Plus and can be used on a personal computer or a workstation. More than 1300 documents have been reviewed by nuclear criticality specialists over the last 5 years to produce over 800 database entries. Nuclear criticality specialists will be able to access the database and retrieve information about topical parameter studies, authors, and chronology. The database places the accumulated knowledge in the nuclear criticality area over the last 50 years at the fingertips of a criticality analyst

  3. Productivity studies of the nuclear waste programme

    International Nuclear Information System (INIS)

    The Swedish Nuclear Inspectorate reviews and supplements the SKB proposal for cost estimations for the nuclear waste programme. These estimations are of great importance for the determination of annual fees to the Nuclear Waste Fund and guarantee amounts in accordance with the Financing Act. The majority of the Nuclear Waste Fund's assets are invested in real interest bonds, issued by the Swedish state. The average duration for the Nuclear Waste Fund investments was 12.8 years at the end of December 2001. From July 1, 2002 on the Nuclear waste Fund investments will consist of nominal and real bonds on the official market. The Fund is increased in line with the Consumer Price Index (KPI). If real costs within the nuclear waste programme increase at a faster rate than the KPI, there is a risk that the Nuclear Waste Fund will be 'under balanced'. SKI has developed a weighted index, the KBS-3-index, to compare the SKB cost re-estimate with. Productivity changes have however no impact on these indices. The KBS-3-index indicates that there might be a risk that the de facto, cost increases will exceed KPI. An improved productivity might however balance the cost escalations. Productivity is normally defined as production divided by the input of production factors. The production can be a quantity measurement or the value added. A common approach is calculation of the labour productivity. The productivity development within different industries in Sweden and in EU varies, and is not only positive. The so called DEA method is used for productivity and efficiency measurements in public and private operations. Efficiency evaluations based on known norms are not made with the DEA models. Instead the evaluation is performed in relation to an empirically based reference technology, a relative efficiency. A selection or an optimisation of output is difficult for the nuclear waste programme. It is not possible to change parts of the nuclear waste programme to something else

  4. Stability of guest molecules in urea canal complexes by canal polymerization

    International Nuclear Information System (INIS)

    It was found that various organic materials are attracted into urea canal by hexanediol diacrylate (HDDA) and long chain compounds. This means that materials which does not form complex by itself are induced in canal by HDDA and long chain compounds. To include with stability perfumes, insecticides, attractants and repellents in urea canal, leaf alcohol was used as a model compound for guest molecules in the canal. The leaf alcohol from the canal released gradually over many days and the release was inhibited for 15 days by long chain compounds and for 30 days by polymerized HDDA after irradiation. After releasing, the leaf alcohol in the canal remained 25 % stable for long chain compounds and 40 % for polymerized HDDA. The dose required for stabilization of leaf alcohol in the urea canal by canal polymerization of HDDA was 30 kGy. (author)

  5. Nuclear power planning and feasibility studies

    International Nuclear Information System (INIS)

    This lecture will review the basic steps associated with planning the introduction of nuclear power. Areas covered will include power market surveys, energy resources evaluations, potential alternative strategies, organisational factors and implementational requirements. The lecture will then consider the implications and requirements associated with establishing the feasibility of a nuclear project. Among others, aspects of power systems integration, site selection reactor type evaluation, cost and economic analysis, influence of contracting strategies, comparison with alternative power generation solutions, financial impact, etc. will be discussed and reviewed. (HK)

  6. Nuclear physics studies using high energy lasers

    International Nuclear Information System (INIS)

    This paper presents several mechanisms expected to be responsible for nuclear excitation in laser-heated plasma. Attempts to detect such processes in nuclei initially in their ground state are discussed in 181Ta and 235U cases. A calculation of the nuclear excitation by electronic transition (NEET) rate is presented in a 201Hg plasma at local thermodynamic equilibrium. We also report on a new way of de-exciting isomeric states in plasma. This indirect decay mode is illustrated in the case of the 84Rb isomer nucleus.

  7. Case studies of application of nuclear forensics to analyze nuclear trafficking activities

    International Nuclear Information System (INIS)

    Discuses the use of nuclear forensics to identify the source of 14 uranium pellets found in Germany. The pellets were found to be homogeneous typical of western european PWR pellets. Based on geometry Siemens , Germany was identified as the only possible manufacturer. The other case study considered was on a metal can containing of 18 grams of uranium dioxide powder found at ulm together with a lead foil containing 1.8 kilograms of uranium dioxide powder plus pellets of Uranium. Four other case studies are considered. the case studies demonstrates the use of nuclear forensics as a key element in combating illicit trafficking of nuclear materials.

  8. For and against nuclear power - a study for social planners

    International Nuclear Information System (INIS)

    A summary is given of contributions by members of a study group of five experts in Holland regarding future nuclear power developments - especially in terms of a contrast between nuclear and fossil fuel power. Aspects considered include growth of installed electric generating capacity, load factors, investment in the transmission line network and safety aspects of the nuclear installation. The latter feature is mainly amplified in terms of radioactive waste, and the proliferation of damage resulting from an accident. (G.C.)

  9. Endoscopic posterior decompression of lumbar canal stenosis

    OpenAIRE

    Yad Ram Yadav; Nishtha Yadav; Vijay Parihar; Yatin Kher; Shailendra Ratre

    2013-01-01

    Lumbar canal stenosis (LCS) is quite common. Surgery is indicated when patient fails to improve after conservative treatment. Endoscopic technique can be used in LCS and lateral recess stenosis. It can be performed in degenerative canal stenosis or with disc bulges. Bilateral severe bony canal stenosis and unstable spine are the contraindications. This procedure should be avoided in patients with a history of trauma. Detailed history and thorough physical examination should be performed to fi...

  10. Maxillary canine with two root canals

    OpenAIRE

    Nagesh Bolla; Sarath Raj Kavuri

    2011-01-01

    To report a rare case of maxillary canine with two root canals. The case describes the treatment of a maxillary canine with two root canals which was referred from department of prosthodontia for intentional root canal treatment for prosthetic rehabilitation. Clinical examination revealed a maxillary canine with carious lesion and responded within normal limits to electric pulp test. Radiographic examination revealed a distal carious lesion (close proximity to pulp) and also appeared to be an...

  11. The number and probability of canalizing functions

    OpenAIRE

    Just, Winfried; Shmulevich, Ilya; Konvalina, John

    2003-01-01

    Canalizing functions have important applications in physics and biology. For example, they represent a mechanism capable of stabilizing chaotic behavior in Boolean network models of discrete dynamical systems. When comparing the class of canalizing functions to other classes of functions with respect to their evolutionary plausibility as emergent control rules in genetic regulatory systems, it is informative to know the number of canalizing functions with a given number of input variables. Th...

  12. The petromastoid canal on computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Krombach, G.A.; Schmitz-Rode, T.; Weidner, J.; Guenther, R.W. [Department of Diagnostic Radiology, University of Technology, Pauwelstrasse 30, 52057 Aachen (Germany); Prescher, A. [Department of Anatomy, University of Technology, Pauwelstrasse 30, 52057 Aachen (Germany); DiMartino, E. [Department of Otorhinolaryngology, University of Technology, Pauwelstrasse 30, 52057 Aachen (Germany)

    2002-11-01

    The objective was to assess visibility and anatomy of the petromastoid canal in high-resolution CT. Computed tomography images of 188 patients were reviewed for delineation of the petromastoid canal. This bony canal connects the mastoid antrum with the cranial cavity and houses the subarcuate artery and vein. The diameter, obtained in the middle portion of the canal, was compared with the diameter of the vestibular and cochlear aqueduct in all patients, and absolute values measured in 20 cases. Collimation was 1 mm in 164 and 2 mm in 24 examinations. Additionally, temporal bone of a cadaver was imaged and microdissected. The petromastoid canal was identified bilaterally in all 164 scans that were obtained with a slice thickness of 1 mm. In 5 of the 24 patients imaged with a collimation of 2 mm, the canal was not visible, most probably due to partial-volume effects. The petromastoid canal had the same diameter as the cochlear aqueduct in 42/44 (right/left), exceeded it in 66/61 and was smaller in 75/78 cases. In comparison to the vestibular aqueduct it had an equal diameter in 38/41 (right/left), exceeded it in 63/61, and was rated as smaller in 82/81 temporal bones. Diameters for the canals were: petromastoid canal 0.51{+-}0.04 mm; cochlear aqueduct 0.57{+-}0.03; and vestibular aqueduct 0.63{+-}0.06 mm. Microdissection of the specimen revealed the entire course of the canal and demonstrated a similar appearance of the structure as in the images. The petromastoid canal can easily be identified on high-resolution, thin-slice CT images. Knowledge of the anatomy of this bony canal prevents misinterpretation as pathological structure, such as fracture line, which might occur if this structure is not known. (orig.)

  13. Linear stability of a fuel channel uniformly heated considering retrofeeding by vacuum. Theoretical study; Estabilidad lineal de un canal combustible uniformemente calentado considerando retroalimentacion por vacios

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez M, V. [Comision Nacional de Seguridad Nuclear y Salvaguardias, 03000 Mexico D.F. (Mexico); Salinas H, J.G.; Espinosa P, G. [Universidad Autonoma Metropolitana-Iztapalapa, 09000 Mexico D.F. (Mexico)

    2000-07-01

    The Technology, Regulation and Services Management of the National Commission of Nuclear Safety and Safeguards in coordinated form with the IPH Department of the Metropolitan Autonomous-Iztapalapa University, developed the present project to study the linear stability in a fuel channel uniformly heated with effects of retrofeeding by vacuums. In this study the methodology used in the analysis of linear stability of the nuclear reactor unit 1 at Laguna Verde power plant is described which represented by an average channel uniformly heated. The conceptual model consists of two cells which represent the two regions in which is divided the channel according to the cooling is in one and two phases, considering the boiling length dependent in the time. It is used the homogeneous flux models for describing the thermohydraulic behavior of the cooling in the two phases region. The neutron processes with the punctual model of the neutron kinetics with a group of retarded neutrons precursors are described. It is studied the behavior of the system in the frequency domain with the transfer functions obtained and it is characterized in four operation states corresponding to the four corners of the low stability zone in the map power-flow Laguna Verde power plant. For these operation states the characteristic frequency is determined and the corresponding Nyquist diagrams are obtained. The results show that the system stability depends on the power-flow relation and that the operations which implicate a reduction of this relation improve the stability of the system (reducing the power introducing control bars with constant cooling flow or increase cooling flow with bars pattern established). The obtained results with effects of retrofeeding by vacuums show that the value of the characteristic frequency is modified very little with respect to the model without retrofeeding, therefore the thermohydraulic processes seem to determine the response of the stability of the system

  14. Mandibular lingual vascular canals (MLVC): Evaluation on dental CTs of a case series

    International Nuclear Information System (INIS)

    Purpose: The aim of this study was to assess the anatomy of the mandibular lingual foramen (MLF) and its linked canals (mandibular lingual vascular canals - MLVC), describing their frequency, diameter, location, and course. Materials and methods: One hundred and fourteen computed tomography (CT) images of the mandible (57 male and 57 female; mean age 44.70 ± 12.53; age range 13-75 years, were evaluated. The CT sections were obtained on axial plane by using a bone reconstruction algorithm and then processed with dedicated software (Dentascan), with a standard protocol. Results: 103 patients (90.35%) had at least one lingual vascular canal and 52 (45.61%) had multiple (two or three) canals. The typical locations of MLVC were the midline of the mandible (median lingual canal [MLC]). The mean diameter of the lingual canals in the midline (MLC) was 0.8 mm ± 0. The direction of MLC progresses in an anterior and slightly caudal sense. Conclusions: Dental CT examination easily demonstrates the presence, position, direction and size of the lingual foramen and of the lingual vascular canals of the mandible. Radiologists and oral surgeons should be aware of these canals and their importance, in order to prevent bleeding complications during implants placement and other surgical procedures.

  15. Mandibular lingual vascular canals (MLVC): Evaluation on dental CTs of a case series

    Energy Technology Data Exchange (ETDEWEB)

    Scaravilli, Maria Serena; Mariniello, Mauro [Department of Oral and Maxillo-Facial Sciences, Section of Oral and Implant Surgery, University of Naples ' Federico II' , Naples (Italy); Sammartino, Gilberto, E-mail: serena.scaravilli@gmail.com [Department of Oral and Maxillo-Facial Sciences, Section of Oral and Implant Surgery, University of Naples ' Federico II' , Naples (Italy)

    2010-11-15

    Purpose: The aim of this study was to assess the anatomy of the mandibular lingual foramen (MLF) and its linked canals (mandibular lingual vascular canals - MLVC), describing their frequency, diameter, location, and course. Materials and methods: One hundred and fourteen computed tomography (CT) images of the mandible (57 male and 57 female; mean age 44.70 {+-} 12.53; age range 13-75 years, were evaluated. The CT sections were obtained on axial plane by using a bone reconstruction algorithm and then processed with dedicated software (Dentascan), with a standard protocol. Results: 103 patients (90.35%) had at least one lingual vascular canal and 52 (45.61%) had multiple (two or three) canals. The typical locations of MLVC were the midline of the mandible (median lingual canal [MLC]). The mean diameter of the lingual canals in the midline (MLC) was 0.8 mm {+-} 0. The direction of MLC progresses in an anterior and slightly caudal sense. Conclusions: Dental CT examination easily demonstrates the presence, position, direction and size of the lingual foramen and of the lingual vascular canals of the mandible. Radiologists and oral surgeons should be aware of these canals and their importance, in order to prevent bleeding complications during implants placement and other surgical procedures.

  16. Studies in Low-Energy Nuclear Science

    Energy Technology Data Exchange (ETDEWEB)

    Carl R. Brune; Steven M. Grimes

    2010-01-13

    This report presents a summary of research projects in the area of low energy nuclear reactions and structure, carried out between March 1, 2006 and October 31, 2009 which were supported by U.S. DOE grant number DE-FG52-06NA26187.

  17. Study of nuclear properties in isospin formalism

    International Nuclear Information System (INIS)

    The statistical theory of hot nuclei was used to extract the nuclear properties such as the asymmetry parameter, single particle level density parameter, entropy ..etc. as functions of isospin temperature and triaxial deformation. These properties are obtained for a temperature of 0.04 MeV for N-Z nuclei in the mass region 80-132

  18. Efficacy of three techniques in cleaning the apical portion of curved root canals.

    Science.gov (United States)

    Wu, M K; Wesselink, P R

    1995-04-01

    Various techniques for root canal instrumentation may have different effects in cleaning curved root canals, especially their apical portions. One hundred thirty-five mesiobuccal canals with an average curvature of 25 degrees from human mandibular molars were treated with step-back, crown-down pressureless, or balanced-force techniques with 2% sodium hypochlorite used as an irrigant. The cleaning efficacy of these techniques was evaluated by counting the remaining surface debris under a stereomicroscope with a calibrated eyepiece micrometer. The results indicated that the apical portion of the canal was less clean than the middle and coronal portions regardless of the technique performed and that the balanced-force technique produced a cleaner apical portion of the canal than did the other techniques studied. PMID:7614212

  19. The microsonics concept: maxillary first molar with five root canals – case report

    Directory of Open Access Journals (Sweden)

    Rodrigo Sanches Cunha

    2011-04-01

    Full Text Available Introduction: The complex anatomy of the root canal system is a continuous challenge for endodontists. Permanent maxillary first molars may present several morphological variations, both in the number and location of roots and canals. Therefore, the success of the endodontic treatment depends on an accurate knowledge of root canal anatomy. Objective and case report: This study describes the endodontic treatment of a permanent maxillary first molar diagnosed with irreversible pulpitis. The technology employed to evaluate the case, namely dental operating microscope associated with ultrasonic tips, was essential to delineate the anatomic characteristics of the tooth to be treated, revealing the presence of five root canals: two mesiobuccal, two distobuccal, and one palatal canal. Conclusion: The knowledge of the tooth anatomy, as well as its possible anatomic variations, combined with the use of current technologies, such as dental operating microscope, ultrasonic tips, and computed tomography, help to enhance the endodontic treatment success.

  20. Semicircular canal dehiscence: comparison of T2-weighted turbo spin-echo MRI and CT

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-04-01

    We assessed the value of MRI for delineation of dehiscence of the superior or posterior semicircular canal, as compared with CT, the current standard study for this entity. We reviewed heavily T2-weighted fast spin-echo images and high-resolution CT of the temporal bones of 185 patients independently semicircular canal dehiscence and its extent. In 30 patients (19 men, 11 women) we identified dehiscence of the bone over the superior and/or posterior semicircular canal on MRI. In 27 of these cases CT also showed circumscribed bone defects. In one patient dehiscence of the superior semicircular canal was initially overlooked on MRI, but seen on CT. MRI imaging thus had a sensitivity of 96% and specificity of 98%. Knowledge of the appearances of this entity on MRI may contribute to early diagnosis in patients with vertigo due to semicircular canal dehiscence. (orig.)