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Sample records for canal study nuclear

  1. Nuclear magnetic resonance tomography of the cervical canal

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    Terwey, B.; Koschorek, F.; Jensen, H.P.

    1985-12-01

    170 patients with suspected lesions of the cervical part of the medulla were examined using nuclear magnetic resonance (NMR) tomography. 27 cases revealed no pathological changes in the regions of the cervical medulla, the cervical canal and of the cervical spine. 143 cases produced pathological findings whose diagnoses determined therapeutical approach. Verified pathological changes comprised anomalies of the cranio-cervical junction like basilar impression and Arnold-Chiari malformation, various types of cavity formation in the cervical medulla (syringomyelia, hydromyelia), demyelinization processes, intramedullary and extramedullary tumours, intervertebral disk degeneration processes, dislocation of intervertebral disks and spondylophytes with spinal stenoses. Sagittal sections in different functional positions allowed to demonstrate the biomechanical effects of extramedullary masses on the cervical medulla. However, proven tumours could not be differentiated successfully using histological methods. Nevertheless, NMR tomography will replace invasive methods like conventional cervical myelography and CT myelography in diagnostic clarification of diseases of the cervical medulla.

  2. A radiographic study of mandibular canal

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    Kim, Won Chul; Lee, Sang Rae [Dept. of Oral Radiology, Division of Dentistry, Kyung Hee University, Seoul (Korea, Republic of)

    1987-11-15

    The author invested the gonial angle, the angle of mandibular and mental canal to the lower border of the mandible, and a relationship of the position of the mandibular canal to the root apex of the posterior teeth and the cortical plate of the lower of the mandible. The materials consisted of 458 pantomograms in male and female aged 11-40 and divided into 5 groups at year intervals and subdivided into 3 groups by gonial angle. The results were as follows: 1. The gonial angle decreased with age, but slight increase occurred over 26-30 years. 2. The average angle of the mandibular canal to the lower border of the mandible was 151.6 degree and did not correlate with age. 3. The average angle of the mental canal to the lower border of the mandible was 36.9 degree and didn't correlate with age. 4. The angles of mandibular and mental canal to the lower border of mandible correlated with gonial angle. 5. The distance from the root apex of the posterior teeth to the upper wall mandibular canal was most short at the region of the distal root of the mandibular second and increased with age at the region of the mandibular second molar. 6. The distance from the lower wall of the mandibular canal to the cortical plate of the lower border of the mandibule was most short at the region of the mesial root of the mandibular first molar and didn't correlate with age.

  3. Assessment of three root canal preparation techniques on root canal geometry using micro-computed tomography: In vitro study

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    Shaikha M Al-Ali

    2012-01-01

    Full Text Available Aim: To assess the effects of three root canal preparation techniques on canal volume and surface area using three-dimensionally reconstructed root canals in extracted human maxillary molars. Materials and Methods: Thirty extracted Human Maxillary Molars having three separate roots and similar root shape were randomly selected from a pool of extracted teeth for this study and stored in normal saline solution until used. A computed tomography scanner (Philips Brilliance CT 64-slice was used to analyze root canals in extracted maxillary molars. Specimens were scanned before and after canals were prepared using stainless steel K-Files, Ni-Ti rotary ProTaper and rotary SafeSiders instruments. Differences in dentin volume removed, the surface area, the proportion of unchanged area and canal transportation were calculated using specially developed software. Results: Instrumentation of canals increased volume and surface area. Statistical analysis found a statistically significant difference among the 3 groups in total change in volume (P = 0.001 and total change in surface area (P = 0.13. Significant differences were found when testing both groups with group III (SafeSiders. Significant differences in change of volume were noted when grouping was made with respect to canal type (in MB and DB (P < 0.05. Conclusion: The current study used computed tomography, an innovative and non destructive technique, to illustrate changes in canal geometry. Overall, there were few statistically significant differences between the three instrumentation techniques used. SafeSiders stainless steel 40/0.02 instruments exhibit a greater cutting efficiency on dentin than K-Files and ProTaper. CT is a new and valuable tool to study root canal geometry and changes after preparation in great details. Further studies with 3D-techniques are required to fully understand the biomechanical aspects of root canal preparation.

  4. RADIOLOGICAL STUDY OF HUMAN LUMBAR VERTEBRAL CANAL IN VIDHARBHA REGION

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    Shruti

    2015-06-01

    Full Text Available Increase in number of patients suffering from backache all over world needs changing health polices and cost benefit analysis, it is important to look at diseases causing low back pain and for this study of radiological structure of lumbar vertebral canal is undertaken. AIMS : To reveal the radiological feature of Human lumbar vert ebral canal. METHOD AND MATERIAL : 50 - xray of lumbar canal was collected from orthopedic department of government medical college, Nagpur. STATISTICAL ANALYSIS : Data is presented in mean ± standard deviation and categorical variable are presented in percen tage. Comparison with previous study is done. RESULT : M aximum measurement as greater in male than female of same age group. CONCLUSION : T he present study and previous studies are compared and the non - significant result is found.

  5. 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...

  6. Assessing the accuracy of tympanometric evaluation of external auditory canal volume: a scientific study using an ear canal model.

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    Al-Hussaini, A; Owens, D; Tomkinson, A

    2011-12-01

    Tympanometric evaluation is routinely used as part of the complete otological examination. During tympanometric examination, evaluation of middle ear pressure and ear canal volume is undertaken. Little is reported in relation to the accuracy and precision tympanometry evaluates external ear canal volume. This study examines the capability of the tympanometer to accurately evaluate external auditory canal volume in both simple and partially obstructed ear canal models and assesses its capability to be used in studies examining the effectiveness of cerumolytics. An ear canal model was designed using simple laboratory equipment, including a 5 ml calibrated clinical syringe (Becton Dickinson, Spain). The ear canal model was attached to the sensing probe of a Kamplex tympanometer (Interacoustics, Denmark). Three basic trials were undertaken: evaluation of the tympanometer in simple canal volume measurement, evaluation of the tympanometer in assessing canal volume with partial canal occlusion at different positions within the model, and evaluation of the tympanometer in assessing canal volume with varying degrees of canal occlusion. 1,290 individual test scenarios were completed over the three arms of the study. At volumes of 1.4 cm(3) or below, a perfect relationship was noted between the actual and tympanometric volumes in the simple model (Spearman's ρ = 1) with weakening degrees of agreement with increasing volume of the canal. Bland-Altman plotting confirmed the accuracy of this agreement. In the wax substitute models, tympanometry was observed to have a close relationship (Spearman's ρ > 0.99) with the actual volume present with worsening error above a volume of 1.4 cm(3). Bland-Altman plotting and precision calculations provided evidence of accuracy. Size and position of the wax substitute had no statistical effect on results [Wilcoxon rank-sum test (WRST) p > 0.99], nor did degree of partial obstruction (WRST p > 0.99). The Kamplex tympanometer

  7. PARAMETERS OF NUCLEAR MAGNETIC RESONANCE IN PATIENTS WITH CONGENITAL NARROWING OF THE LUMBAR SPINAL CANAL

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    ELIU HAZAEL MORALES-RANGEL

    Full Text Available ABSTRACT Objective: To compare the morphological parameters of magnetic resonance in patients with congenital narrowing of the lumbar spinal canal with patients with low back pain. Methods: A descriptive, retrospective, observational study was conducted with measurements in the axial and sagittal magnetic resonance sections of the vertebral body and canal of the lumbar spine of 64 patients with diagnosis of low back pain, which were compared with resonance images taken from 31 Mexican patients with congenital narrowing of the lumbar spinal canal. Results: The results show that patients with congenital narrowing of the lumbar spinal canal in the axial sections have a difference in diameters, being L2<13.9 mm, L3<13.3 mm, L4<12.9 mm, L5<13.1 mm, compared with controls L2<20.5 mm, L3<20.5 mm, L4<19.3 mm, L5<18.1 mm with p = 0.000. Conclusions: We found different measurements in the Mexican population compared to those found by similar studies. With the parameters obtained, it would be possible to make the proper diagnosis, surgical planning, and treatment.

  8. Anatomo-radiological study of the Superior Semicircular Canal Dehiscence

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    Crovetto, M., E-mail: macdlt@telefonica.net [Otolaryngology Department, Hospital de Basurto, University of the Basque Country, Avenida de Montevideo 18, Bilbao 48013, Vizcaya (Spain); Whyte, J., E-mail: jwhite@unizar.es [Faculty of Medicine, Department of Human Anatomy and Histology, University of Zaragoza, C/Domingo Mirall s/n, Zaragoza (Spain); Rodriguez, O.M., E-mail: OLIVIAMARIA.RODRIGUEZSANVICENT@osakidetza.net [Hospital de Cruces, Baracaldo, Vizcaya (Spain); Lecumberri, I., E-mail: INIGO.LECUMBERRICORTES@osakidetza.net [Hospital de Basurto, Avenida Montevideo 18, Bilbao 498013 (Spain); Martinez, C., E-mail: claudiorayosx@yahoo.es [Hospital General de la Defensa, Via Iberica s/n Zaragoza (Spain); Elexpuru, J., E-mail: jelexpuru@mac.com [Hospital de Basurto, Avenida de Montevideo 18, Bilbao 48013, Vizcaya (Spain)

    2010-11-15

    Introduction: The main purpose of this study is to determine the radiological incidence of Superior (SSCD) and Posterior Semicircular Canal Dehiscence (PSCD) and to compare radiologic SSCD to the incidence of this condition on cadaver specimen. We have also analysed the relation between the ossification state of the semicircular canals and the degree of mastoid pneumatization and integrity of Tegmen Tympani. Material and methods: Temporal bones have been investigated by means of CT scan on patients and direct observation on cadaver specimen, respectively. Results: 604 ears and 160 cadaver temporal bones have been investigated by means of CT scan and direct observation, respectively. 3.6% and 0.3% of the studied ears had SSCD and PSCD, respectively, on CT scan. Only 0.6% of the cadaver specimen ears did have anatomical SSCD. Degree of pneumatization of the mastoid bone is related to the mean thickness of bone overlying the Superior and Posterior Semicircular Canal. Radiological absence of Tegmen Tympani is more frequent in ears that also have radiologic SSCD. Conclusion: CT scanning gives higher incidence figures of SSCD than anatomical studies, 3.6% vs. 0.6%. We also found a 0.6% incidence of radiological PSCD in the studied ears. There is a direct relation between the degree of ossification of Superior and Posterior Semicircular Canal and certain temporal bone anatomic features: temporal bone pneumatization and absence/presence of Tegmen Tympani or Antri.

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

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    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.

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

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    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.

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

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    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.

  12. Computed Tomography Evaluation of Canal Transportation and Volumetric Changes in Root Canal Dentin of Curved Canals Using Mtwo, ProTaper and ProTaper Next Rotary System-An In-vitro Study

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    Shivashankar, Mayuri Biccodu; Jayasheel, Arun; Kenchanagoudra, Mallikarjun Goud

    2016-01-01

    Introduction Complete cleaning and shaping of root canal system is of paramount importance to achieve a successful root canal treatment. There are various rotary Ni-Ti systems available in the market to achieve mechanical goal of root canal preparation. But aggressive preparation of root canal with such systems would result in canal transportation and excess root dentin removal that would be one of the major reasons to decide the prognosis of root canal treated tooth. Aim The present study was conducted to compare the root canal preparation in terms of canal transportation and volumetric changes in the root canal dentin among three Ni-Ti file systems, namely Mtwo, ProTaper (PT) and ProTaper NEXT (PTN) file system, using Computed Tomography (CT). Materials and Methods A total of 45 mesiobuccal root canals of extracted first molar teeth with completely formed root apices and angle of curvature ranging between 10°- 35° were selected. These teeth were randomly divided into three experimental groups containing 15 teeth each, based on rotary system used. Group-I: Mtwo files, Group-II: PT files and Group-III: PTN files. Pre-instrumentation CT images were obtained at three cross-sectional planes – 3mm, 7mm and 11mm from apical end of the root. Similarly, post-instrumentation images were obtained. Shortest distance from the edge of the canal to the periphery of the root was analyzed by using Analysis of Variance. Results All three file systems tested in the present study presented similar behaviour with respect to the root canal transportation. Lesser canal transportation was recorded in Mtwo. But no statistically significant difference was seen in terms of canal transportation and volume of dentin removed between all three rotary systems (p>0.05). Conclusion Mtwo, PT and PTN rotary systems have similar behaviour with respect to canal transportation and volume of dentin removed. PMID:28050495

  13. An Osteologic Study of Cranial Opening of Optic Canal in Gujarat Region

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    Singh, Praveen R

    2016-01-01

    Introduction Optic canal is a bony canal situated in between the roots of lesser wings of sphenoid, lateral to body of sphenoid. It transmits optic nerve and ophthalmic artery, surrounded by meninges. Various authors have studied variations in skull foramina and correlated clinically, as variants in the body structures have been found to be associated with many inherited or acquired diseases. Aim The present study aimed to examine morphologic and morphometric variations in cranial openings of optic canals. Materials and Methods The study was undertaken in total 150 dry adult human skulls. The variations in size, shape, presence or absence and duplication or multiplication if any, in optic canal were observed bilaterally. Unusual features such as recess, fissure and notch were also observed bilaterally. Student’s t-test was applied to compare size of cranial openings of optic canal on both sides. Similarly, morphologic features related with the canal were studied by calculating frequency and proportions of various parameters. Results Optic canal was present in all 150 skulls studied bilaterally. The mean maximum dimension of the canal at cranial opening was 5.03±0.72 mm on right side and 5.02±0.76 mm on left side. The shape of the canal was ovoid at cranial opening in all the skulls studied. Duplication of optic canal was present in one skull on left side. Recess was found in 105(35%) sides of total skulls observed. Fissure was found in 20(6.67%) sides and notch was observed in 30(10%) sides of total skulls. Conclusion The optic canal showed variability in various parameters. Knowledge regarding variations in size, shape and unusual features on cranial opening of optic canal can be helpful to clinicians while approaching optic canal for various invasive procedures such as optic nerve decompression. PMID:28050353

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

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

    2016-01-01

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

  15. 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.

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

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    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.

  17. Root canal anatomy of mandibular first premolars in an Emirati subpopulation: A laboratory study

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    Abraham, Sheela Balu; Gopinath, Vellore Kannan

    2015-01-01

    Objective: The purpose of this study was to determine the root canal anatomy of mandibular first premolar teeth in an Emirati subpopulation using a decalcification and clearing method. Materials and Methods: One hundred permanent mandibular first premolar teeth extracted for orthodontic purposes from an Emirati subpopulation from the United Arab Emirates were used for this study. They were subjected to decalcification and clearing. The tooth length, the canal orifice shape, mesial invagination, canal pattern, the location of apex, presence of lateral canals, and intercanal communications were determined. Results: The most common canal pattern was the Vertucci Type I (65%) followed by Type V (14%) and Type IV (13%). The most common type of canal orifice seen was the oval shape (36%) followed by the round shape (25%). Mesial invaginations were seen in 44% of the teeth. The mean tooth length was 19.9 mm, and apical deltas were seen in 24% of teeth. Conclusion: The Vertucci Type I canal pattern was the most prevalent in the mandibular first premolars while the occurrence of multiple canals was noted in 35% of this population. PMID:26929684

  18. The connective tissue of the adductor canal--a morphological study in fetal and adult specimens.

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    de Oliveira, Flavia; de Vasconcellos Fontes, Ricardo Bragança; da Silva Baptista, Josemberg; Mayer, William Paganini; de Campos Boldrini, Silvia; Liberti, Edson Aparecido

    2009-03-01

    The adductor canal is a conical or pyramid-shaped pathway that contains the femoral vessels, saphenous nerve and a varying amount of fibrous tissue. It is involved in adductor canal syndrome, a claudication syndrome involving young individuals. Our objective was to study modifications induced by aging on the connective tissue and to correlate them to the proposed pathophysiological mechanism. The bilateral adductor canals and femoral vessels of four adult and five fetal specimens were removed en bloc and analyzed. Sections 12 microm thick were obtained and the connective tissue studied with Sirius Red, Verhoeff, Weigert and Azo stains. Scanning electron microscopy (SEM) photomicrographs of the surfaces of each adductor canal were also analyzed. Findings were homogeneous inside each group. The connective tissue of the canal was continuous with the outer layer of the vessels in both groups. The pattern of concentric, thick collagen type I bundles in fetal specimens was replaced by a diffuse network of compact collagen bundles with several transversal fibers and an impressive content of collagen III fibers. Elastic fibers in adults were not concentrated in the thick bundles but dispersed in line with the transversal fiber system. A dynamic compression mechanism with or without an evident constricting fibrous band has been proposed previously for adductor canal syndrome, possibly involving the connective tissue inside the canal. The vessels may not slide freely during movement. These age-related modifications in normal individuals may represent necessary conditions for this syndrome to develop.

  19. 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...

  20. An imaging study of the facial nerve canal in congenital aural atresia.

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    Zhao, Shouqin; Han, Demin; Wang, Zhenchang; Li, Jie; Qian, Yanni; Ren, Yuanyuan; Dong, Jiyong

    2015-01-01

    We conducted a prospective study to investigate the abnormalities of the facial nerve canal in patients with congenital aural atresia by computed tomography (CT). Our study population was made up of 99 patients--68 males and 31 females, aged 6 to 22 years (mean: 13.5)--who had unilateral congenital aural atresia without any inner ear malformations. We compared our findings in these patients with those in 50 controls-33 males and 17 females, aged 5 to 22 years (mean: 15.0)-who had normal ears. We classified the congenital aural atresia patients into three groups (A, B, and C) according to their Jahrsdoerfer grading scale score (≥8; 6 or 7; and ≤5, respectively). The course of the facial nerve canal in both the controls and the study patients was determined by temporal bone CT with multiplanar reconstruction. The distances from different parts of the facial nerve canal to surrounding structures were also measured. The course of the facial nerve canal in the normal ears did not vary much, and there were no statistically significant differences according to head side and sex. In groups B and C, the tympanic segment, mastoid segment, and angle of the second genu of the facial nerve canal were all significantly smaller than those of the controls (p < 0.01 in all cases). Statistically, the tympanic segment of the facial nerve canal in patients with congenital aural atresia was downwardly displaced. The mastoid segment of the facial nerve canal in these patients was more anterior than that of the controls. We conclude that congenital aural atresia is often accompanied by abnormalities of the facial nerve canal, especially in the tympanic segment, the mastoid segment, and the second genu. We found that the lower the Jahrsdoerfer score was, the shorter the tympanic segment was and the more forward the mastoid segment was.

  1. The Length of the Greater Palatine Canal in a Lebanese Population: a Radio-anatomical Study

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    Aoun, Georges; Nasseh, Ibrahim

    2016-01-01

    Objective: The aim of this study was to evaluate the length of the greater palatine canal in a Lebanese population using cone-beam computed tomography (CBCT) technology. Material and methods: In this study, we measured the length of 148 greater palatine canals in 74 CBCT images of Lebanese adult patients (38 females and 36 males). The data obtained was analyzed statistically to determine 1) if age is related to the length of the canal, 2) if the length of the left side tends to be systematically larger or smaller than the length of the right side, and 3) if the mean length of the canals in females is different than the one in males. Results: In a sagittal plane, the average length of the greater palatine canal was 30.62 (30.64 mm on the right and 30.60 mm on the left). Conclusion: Within the limits of this study, we concluded that in our sample in a Lebanese population, the length of the greater palatine canal does not significantly vary according to age, gender, and side. PMID:28077902

  2. Nuclear spectroscopic studies

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    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.

  3. Root Canal Anatomy and Morphology of Mandibular First Molars in a Selected Iranian Population: An In Vitro Study

    Science.gov (United States)

    Mohammadzadeh Akhlaghi, Nahid; Khalilak, Zohreh; Vatanpour, Mehdi; Mohammadi, Saman; Pirmoradi, Sakineh; Fazlyab, Mahta; Safavi, Kamran

    2017-01-01

    Introduction: The aim of this study was to evaluate root canal anatomy of mandibular first molars (MFM) in a selected Iranian Population using clearing technique. Methods and Materials: A total of 150 extracted MFMs were cleared. The root canal morphology (including the root numbers and root length) and the anatomy of the root canal system (including is the number and type of canals based on Vertucci’s classification, canal curvature according to Schneider's method and the presence of isthmus) was evaluated using the buccolingual and mesiodistal parallel x-rays and stereomicroscope. The data were analyzed using the chi-square test. Results: Two and three roots were present in 96.7% and 33% of the teeth, respectively (P=0.0001). All the teeth (100%) had two canals in the mesial root, while 61.3% of the samples had one distal root canal (P=0.006). The root canal configuration in the mesial canal included type IV (55.3%) and type II (41.3%) (P=0.0001). In doubled-canalled distal roots, 68.8% and 24.3% were type II and type IV, respectively (P=0.0001). Isthmii were observed in 44.6% of mesial and 27.3% of distal roots (P=0.0001). Conclusion: The notable prevalence of type IV configuration in both roots of mandibular first molars, presence of isthmus and root curvature, necessitates the careful negotiation and cleaning of all accessible canal spaces. PMID:28179932

  4. 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

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

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    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

  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. A comparative study of intra canal stress pattern in endodontically treated teeth with average sized canal diameter and reinforced wide canals with three different post systems using finite element analysis

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    Kaur Amandeep

    2010-01-01

    Full Text Available Study methodology: This is a comparative study of intra canal stress patterns in endodontically treated maxillary central incisor with: average sized canal diameter and wide canals reinforced with three different post systems - cast post and core, carbon fiber post, stainless steel post; restored with ceramic crown using finite element analysis (FEA. All the models were subjected to a force of 100N applied at 450 to the long axis of the tooth at the middle third of the palatal surface of the restored ceramic crown. Results: The FEA revealed that all the post systems showed maximum stress in the coronal and middle third of the root. Maximum stress was seen on the inner dentinal wall in case of stainless steel post followed by cast gold and carbon fiber post, both in the models without reinforcement as well as in the reinforced models.

  8. Dispositivo de posicionamiento de muestras biológicas para su irradiación en un canal radial de un reactor nuclear // Biological samples positioning device for irradiations on a radial channel at the nuclear research reactor

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    Maritza Rodríguez - Gual

    2010-05-01

    Full Text Available ResumenPor la demanda de un dispositivo experimental para el posicionamiento de las muestras biológicaspara su irradiación en un canal radial de un reactor nuclear de investigaciones en funcionamiento, seconstruyó y se puso en marcha un dispositivo para la colocación y retirada de las muestras en laposición de irradiación de dicho canal. Se efectuaron las valoraciones económicas comparando conotro tipo de dispositivo con las mismas funciones. Este trabajo formó parte de un proyectointernacional entre Cuba y Brasil que abarcó el estudio de los daños inducidos por diferentes tipos deradiación ionizante en moléculas de ADN. La solución propuesta es comprobada experimentalmente,lo que demuestra la validez práctica del dispositivo. Como resultado del trabajo, el dispositivoexperimental para la irradiación de las muestras biológicas se encuentra instalado y funcionando yapor 5 años en el canal radial # 3(BH#3 Palabras claves: reactor nuclear de investigaciones, dispositivo para posicionamiento de muestras,___________________________________________________________________________AbstractFor the demand of an experimental device for biological samples positioning system for irradiationson a radial channel at the nuclear research reactor in operation was constructed and started up adevice for the place and remove of the biological samples from the irradiation channels withoutinterrupting the operation of the reactor. The economical valuations are effected comparing withanother type of device with the same functions. This work formed part of an international projectbetween Cuba and Brazil that undertook the study of the induced damages by various types ofionizing radiation in DNA molecules. Was experimentally tested the proposed solution, whichdemonstrates the practical validity of the device. As a result of the work, the experimental device forbiological samples irradiations are installed and operating in the radial beam hole #3(BH#3

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

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    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.

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

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    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.

  11. A pilot study to assess adductor canal catheter tip migration in a cadaver model.

    Science.gov (United States)

    Leng, Jody C; Harrison, T Kyle; Miller, Brett; Howard, Steven K; Conroy, Myles; Udani, Ankeet; Shum, Cynthia; Mariano, Edward R

    2015-04-01

    An adductor canal catheter may facilitate early ambulation after total knee arthroplasty, but there is concern over preoperative placement since intraoperative migration of catheters may occur from surgical manipulation and result in ineffective analgesia. We hypothesized that catheter type and subcutaneous tunneling may influence tip migration for preoperatively inserted adductor canal catheters. In a male unembalmed human cadaver, 20 catheter insertion trials were divided randomly into one of four groups: flexible epidural catheter either tunneled or not tunneled; or rigid stimulating catheter either tunneled or not tunneled. Intraoperative patient manipulation was simulated by five range-of-motion exercises of the knee. Distance and length measurements were performed by a blinded regional anesthesiologist. Changes in catheter tip to nerve distance (p = 0.225) and length of catheter within the adductor canal (p = 0.467) were not different between the four groups. Two of five non-tunneled stimulating catheters (40 %) were dislodged compared to 0/5 in all other groups (p = 0.187). A cadaver model may be useful for assessing migration of regional anesthesia catheters; catheter type and subcutaneous tunneling may not affect migration of adductor canal catheters based on this preliminary study. However, future studies involving a larger sample size, actual patients, and other catheter types are warranted.

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

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    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.

  13. 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)

  14. Ascidian introductions through the Suez Canal: The case study of an Indo-Pacific species.

    Science.gov (United States)

    Rius, Marc; Shenkar, Noa

    2012-10-01

    Although marine biological invasions via the Suez Canal have been extensively documented, little is known about the introduction of non-indigenous ascidians (Chordata, Ascidiacea), a group containing particularly aggressive invasive species. Here, we used a multidisciplinary approach to study the introduction of the ascidian Herdmania momus into the Mediterranean Sea. We reviewed its taxonomy and global distribution, and analyzed how genetic variation is partitioned between sides of the Suez Canal. The taxonomic revision showed that H. momus currently has a wide Indo-Pacific distribution. Genetic data indicated two well-differentiated colonization histories across the eastern Mediterranean. Our findings suggest that the range expansion of H. momus has been greatly facilitated by the combined effect of human-mediated transport and the species' ability to adapt to different environments. The integrative approach presented here is critical to attain a holistic understanding of marine biological invasions, especially when studying groups with a poorly resolved taxonomy.

  15. A study on the nuclear foreign policy

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Jae Soo; Lee, H. M.; Jun, E. J.; Lee, D. H.; Lee, B. W.; Won, B. C.; Kim, H. J.

    2011-12-15

    This study addresses four arenas to assist national nuclear foreign policies under international nuclear nonproliferation regimes. Firstly, this study analyzes the trends 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 fissile material cut-off treaty. Secondly, this study analyzes the trends of international nuclear organizations and fora, which include the International Atomic Energy Agency (IAEA) as a central body of international nuclear diplomacy and technical cooperation and International Framework for Nuclear Energy Cooperation (IFNEC) as a forum for international nuclear cooperation. Thirdly, this study analyzes the nuclear foreign policy of the U. S. Administration and reviews bilateral nuclear cooperation agreement between the ROK and the other countries including the U. S. Lastly, this study analyzes the nuclear issues of North Korea and Iran and multilateral nuclear approaches as assurances of nuclear fuel supply.

  16. Dentin Morphology of Root Canal Surface: A Quantitative Evaluation Based on a Scanning Electronic Microscopy Study

    OpenAIRE

    Giuseppe Lo Giudice; Giuseppina Cutroneo; Antonio Centofanti; Alessandro Artemisia; Ennio Bramanti; Angela Militi; Giuseppina Rizzo; Angelo Favaloro; Alessia Irrera; Roberto Lo Giudice; Marco Cicciù

    2015-01-01

    Dentin is a vital, hydrated composite tissue with structural components and properties that vary in the different topographic portions of the teeth. These variations have a significant implication for biomechanical teeth properties and for the adhesive systems utilized in conservative dentistry. The aim of this study is to analyse the root canal dentin going from coronal to apical zone to find the ratio between the intertubular dentin area and the surface occupied by dentin tubules varies. Ob...

  17. Comparative evaluation of canal cleaning ability of various rotary endodontic filesin apical third: A scanning electron microscopic study

    Science.gov (United States)

    Jadhav, Ganesh Ranganath; Mittal, Priya; Kulkarni, Anish; Syed, Shibli; Bagul, Ravikiran; Elahi, Saina; Kalra, Dheeraj

    2016-01-01

    Background: The purpose of this study was to evaluate the canal cleaning ability of three novel endodontic rotary instruments and compare with ProTaper files as a control in apical third of root canals under scanning electron microscopy (SEM). Materials and Methods: Eighty freshly extracted mandibular premolars were selected according to inclusion criteria. Buccal cusp tips were ground to ensure having a flat coronal reference point with a total tooth length of 16 mm for all samples. Teeth were divided equally into four groups: Group I (ProTaper group), Group II (ProTaper next group), Group III (variable taper group), and Group IV (self-adjusting file [SAF] group). Using SEM, the dentinal surfaces were observed and rated at apical thirds with a magnification of ×1000 for the presence/absence of smear layer and debris. Descriptive analysis was performed, and analysis of variance with Bonferroni post hoc test was carried out for comparison between the groups, at a significance level of 0.05. Results: There was statistically significant difference between Group II and Group IV for debris (P = 0.047) and smear layer (P = 0.037). Conclusion: In apical third of root canal, SAF showed statistically significant canal cleaning ability due to combined effect of continuous streaming irrigation with effectively replacing the irrigant from the apical portion of the root canal, irrigants activation through the creation of turbulence, and its self-adapting design to root canal anatomy with a scrubbing motion on the canal walls. PMID:28182065

  18. 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.

  19. 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.

  20. Apical sealing ability of two novel root canal sealers: An ex-vivo study

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    Priyanka Setia

    2013-01-01

    Full Text Available Objective: The objective was to compare the sealing ability of two root canal sealers viz.: Hybrid Root SEAL (Sun Medical, Tokyo, Japan and iRoot SP (Innovative BioCeramix Inc., Vancouver, Canada. Materials and Methods: A sample of 60 permanent single rooted, human maxillary central incisors of similar sizes was selected for the study. The teeth were decoronated and randomly divided into two groups viz.: Group A and Group B, comprising of thirty teeth each. In Group A, Hybrid Root SEAL and Group B, iRoot SP were used as root canal sealers along with Gutta-percha cones using lateral condensation technique to obturate the canals. After obturation roots were covered with nail paint except 2.0 mm of root and stored in 0.5% methylene blue dye for 1 week. The teeth were immersed in 10 ml of 65% nitric acid for complete dissolution and subsequently subjected to UV spectrophotometer to quantify the concentration of the dye in each sample. The data were analyzed using the unpaired t-test. Results: The mean dye leakage value in Group B (0.368 was less as compared to Group A (0.408. However, statistically the difference was nonsignificant (P = 0.053. Conclusion: There was no statistically significant difference among the two groups.

  1. Three-Dimensional Analysis of the Characteristics of the Femoral Canal Isthmus: An Anatomical Study

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    Xiu-yun Su

    2015-01-01

    Full Text Available Purpose. To establish a new approach for measuring and locating the femoral intramedullary canal isthmus in 3-dimensional (3D space. Methods. Based on the computed tomography data from 204 Chinese patients, 3D models of the whole femur and the corresponding femoral isthmus tube were reconstructed using Mimics software (Materialise, Haasrode, Belgium. The anatomical parameters of the femur and the isthmus, including the femur length and radius, and the isthmus diameter and height, were measured accordingly. Results. The mean ratio of the isthmus height versus the femoral height was 55 ± 4.8%. The mean diameter of the isthmus was 10.49 ± 1.52 mm. The femoral length, the isthmus diameter, and the isthmus tube length were significantly larger in the male group. Significant correlations were observed between the femoral length and the isthmus diameter (r=0.24, p<0.01 and between the femoral length and the isthmus height (r=0.6, p<0.01. Stepwise linear regression analyses demonstrated that the femoral length and radius were the most important factors influencing the location and dimension of the femoral canal isthmus. Conclusion. The current study developed a new approach for measuring the femoral canal and for optimization of customer-specific femoral implants.

  2. 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.).

  3. Evaluation of Mandibular Anterior Nutrient Canals in Periodontal Diseases: A Prospective Case Control Radiographic Study

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    Govind Singh

    2011-01-01

    Conclusions: The prevalence of nutrient canals was higher in patients with periodontitis. As age advanced, prevalence was more. Increased frequency of nutrient canals of 3 or more than 3 was seen with increased seventy of bone loss.

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

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    Rahul Kumar

    2013-01-01

    Full Text Available 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 completed before WL determination versus late CF (flaring completed after WL determination. Selected were 90 canals of extracted maxillary or mandibular first molars (mesial root of mandibular molars and the mesiobuccal root of the maxillary molars from three groups. CF was accomplished for the SS group using G. G. drills and for the Ni-Ti group using rotary ProTaper and Hero Shaper files. WL was determined by a digital vernier caliper before CF, immediately after CF, and again after canal preparation. Statistical Analysis: A repeated measures analysis of variance (ANOVA test and a Tukey′s multiple prosthoc test were used for this study. Results: Results indicated that WL decreased for all canals as a result of canal preparation. The mean decrease in WL was significantly greater for the SS group (−0.77 ± 0.42 mm than for the Ni-Ti groups (−0.33 mm ± 0.44. Less change in WL occurred in all groups when initial WL was determined after CF. Conclusion: WL in curved canals consistently decreases during the course of instrumentation. Clinician should keep this in mind for better treatment outcome.

  5. CANAL CONFIGURATION IN THE ROOTS OF MAXILLARY SECON D PREMOLAR: A CLINICAL STUDY

    Directory of Open Access Journals (Sweden)

    Ganesh.

    2012-10-01

    Full Text Available ABSTRACT: Modified access cavity preparation and X ray- interpre tation were used clinically to find out the additional canals in the root of maxil lary second premolars. In 85% of the case two canals were located and treated, of these 30% had t wo separate apical foramen and 50.66% had two canal, joined at the apical third in 5% of the cases, two roots with two different canals were located and in 15% of the cases, one canal was loca ted KEY WORDS: Access Preparation, Apical Foramen.

  6. Bilateral presence of two root canals in maxillary central incisors: A rare case study

    Directory of Open Access Journals (Sweden)

    M Kavitha

    2014-01-01

    Full Text Available Success in root canal treatment is achieved after thorough cleaning and shaping followed by complete obturation of the canal system. Therefore, endodontic therapy requires specific and complete knowledge of the internal and external dental anatomy, and its variations in presentation. The internal anatomy of the maxillary central incisor is well-known and usually presents one root canal system. This case report describes an endodontic treatment of traumatized both maxillary central incisors with two canal systems. Knowledge of dental anatomy is fundamental for proper endodontic practice. When root canal treatment is performed, the clinician should be aware that both external and internal anatomy may be abnormal.

  7. Bilateral presence of two root canals in maxillary central incisors: A rare case study.

    Science.gov (United States)

    Kavitha, M; Gokul, Kannan; Ramaprabha, B; Lakshmi, Amudha

    2014-04-01

    Success in root canal treatment is achieved after thorough cleaning and shaping followed by complete obturation of the canal system. Therefore, endodontic therapy requires specific and complete knowledge of the internal and external dental anatomy, and its variations in presentation. The internal anatomy of the maxillary central incisor is well-known and usually presents one root canal system. This case report describes an endodontic treatment of traumatized both maxillary central incisors with two canal systems. Knowledge of dental anatomy is fundamental for proper endodontic practice. When root canal treatment is performed, the clinician should be aware that both external and internal anatomy may be abnormal.

  8. 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).

  9. Nutrient canal of the fibula

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Joo-Hyuk; Ehara, Shigeru; Tamakawa, Yoshiharu [Departments of Radiology, Iwate Medical University School of Medicine, Morioka (Japan); Horiguchi, Masahura [Department of Anatomy I, Iwate Medical University School of Medicine, Morioka (Japan)

    2000-01-01

    Objective. To investigate the radiological features of the nutrient canal in the fibula.Design and patients. One hundred and seventy-nine dried fibulae were studied regarding the type, number, location, and direction of the nutrient canal. They were classified into a usual type (type I: a radiolucent line confined to the cortex) and an atypical type (type II: a radiolucent line extending beyond the cortex).Results. Among the total of 230 nutrient canals seen on radiography, 197 (86%) were type I and 33 (14%) were type II. On CT scans, the ossified rim of the canal extended into the medullary cavity in type II canals. The most common site was the posteromedial aspect in both type I and type II canals. Type II canals were significantly more common in fibulae with two or three nutrient canals. The frequency of the upward direction was more common in type II canals.Conclusion. Nutrient canals with extension of the ossified rim into the medullary canal are the cause of linear lucency that may simulate a fracture. Their features are slightly different from those of usual canals. (orig.)

  10. Studies of nuclear fuel by means of nuclear spectroscopy methods

    Energy Technology Data Exchange (ETDEWEB)

    Jansson, Peter

    2000-02-01

    This paper is a summary text of several works performed by the author regarding spectroscopic measurements on spent nuclear fuel. Methods for determining the decay heat of spent nuclear fuel by means of gamma-ray spectroscopy and for verifying the integrity of nuclear fuel by means of tomography is presented. A summary of work performed regarding gamma-ray detector technology for studies of fission gas release is presented.

  11. Theoretical studies in nuclear reactions and nuclear structure. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    1992-05-01

    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{sup +}e{sup {minus}} problem and heavy ion dynamics.

  12. Theoretical studies in nuclear reactions and nuclear structure

    Energy Technology Data Exchange (ETDEWEB)

    1992-05-01

    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{sup +}e{sup {minus}} problem and heavy ion dynamics.

  13. Dentin Morphology of Root Canal Surface: A Quantitative Evaluation Based on a Scanning Electronic Microscopy Study

    Science.gov (United States)

    Lo Giudice, Giuseppe; Cutroneo, Giuseppina; Centofanti, Antonio; Artemisia, Alessandro; Bramanti, Ennio; Militi, Angela; Rizzo, Giuseppina; Favaloro, Angelo; Irrera, Alessia; Lo Giudice, Roberto; Cicciù, Marco

    2015-01-01

    Dentin is a vital, hydrated composite tissue with structural components and properties that vary in the different topographic portions of the teeth. These variations have a significant implication for biomechanical teeth properties and for the adhesive systems utilized in conservative dentistry. The aim of this study is to analyse the root canal dentin going from coronal to apical zone to find the ratio between the intertubular dentin area and the surface occupied by dentin tubules varies. Observations were conducted on 30 healthy premolar teeth extracted for orthodontic reasons in patients aged between 10 and 14. A SEM analysis of the data obtained in different canal portions showed that, in the coronal zone, dentinal tubules had a greater diameter (4.32 μm) than the middle zone (3.74 μm) and the apical zone (1.73 μm). The average number of dentinal tubules (in an area of 1 mm2) was similar in coronal zone (46,798 ± 10,644) and apical zone (45,192 ± 10,888), while in the middle zone they were lower in number (30,940 ± 7,651). However, intertubular dentin area was bigger going from apical to coronal portion. The differences between the analysed areas must be considered for the choice of the adhesive system. PMID:26413504

  14. Dentin Morphology of Root Canal Surface: A Quantitative Evaluation Based on a Scanning Electronic Microscopy Study

    Directory of Open Access Journals (Sweden)

    Giuseppe Lo Giudice

    2015-01-01

    Full Text Available Dentin is a vital, hydrated composite tissue with structural components and properties that vary in the different topographic portions of the teeth. These variations have a significant implication for biomechanical teeth properties and for the adhesive systems utilized in conservative dentistry. The aim of this study is to analyse the root canal dentin going from coronal to apical zone to find the ratio between the intertubular dentin area and the surface occupied by dentin tubules varies. Observations were conducted on 30 healthy premolar teeth extracted for orthodontic reasons in patients aged between 10 and 14. A SEM analysis of the data obtained in different canal portions showed that, in the coronal zone, dentinal tubules had a greater diameter (4.32 μm than the middle zone (3.74 μm and the apical zone (1.73 μm. The average number of dentinal tubules (in an area of 1 mm2 was similar in coronal zone (46,798±10,644 and apical zone (45,192±10,888, while in the middle zone they were lower in number (30,940±7,651. However, intertubular dentin area was bigger going from apical to coronal portion. The differences between the analysed areas must be considered for the choice of the adhesive system.

  15. Study on 3D visualization application for the Grand Canal heritage site research

    Science.gov (United States)

    Du, Xiaoping; Fan, Xiangtao; Tan, Jian; Zhu, Junjie

    2010-11-01

    This study focuses on two problems in 3D visualization application for heritage site research. Firstly, methods for large scale terrain modeling and rendering were presented. Complex virtual environments were constructed with sequences of remote sensing images and DEM data. The algorithm of precise 3D scenes modeling was optimized. At the same time, the spatial index of quadtree and the images cache management strategies were introduced for improving the performance of interactive 3D visualization system. A novel method creating a mapping between 3D models and the image textures were put forward, so that the models and the textures can be managed respectively. As a result, the capacity of massive 3D terrain surface models management was enhanced as well as the real-time rendering was accelerated. Secondly, methods for 3D culture relics modeling were presented. The culture relics and ancient buildings of the Canal were simulated, which will contribute to its reconstruction and protection. Some ancient water facilities such as ship-lock and docks models and animated navigation scenes were created based on the construction principle and architecture of the Canal transport hub.

  16. 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.

  17. A Cone Beam Computed Tomography (CBCT) evaluation of MB2 canals in endodontically treated permanent maxillary molars. A retrospective study in Indian population

    Science.gov (United States)

    Sontakke, Subodh; Karjodkar, Freny; Gupta, Pankaj; Mandwe, Ashish; Banga, K.S

    2017-01-01

    Background Current technological advances have allowed application of different study designs and techniques for investigation of dental anatomy. Some clinical studies have provided evidence that Cone Beam computed tomography (CBCT) scanning is an important resource in assessment of root canal systems notably to identify MB2 canals in maxillary molars as CBCT scans allow in vivo dental investigation in axial, sagittal and coronal planes simultaneously. The current study was undertaken to detect and evaluate filled/unfilled MB2 canals in endodontically treated, asymptomatic maxillary molars utilizing cone beam computed tomography (CBCT). Material and Methods A retrospective study of 100 CBCTs of patients were underwent scanning for various treatment modalities, with asymptomatic endodontically treated permanent first and second maxillary molars were selected. History of root canal treatment varied from minimum of 1 year to a maximum of 10 years. Axial and paraxial images obtained were used to assess the presence of MB2 canal. Paraxial images were used to assess the periapical status. Results Of the 100 scans, 66 were of permanent maxillary first molar and 34 were of permanent maxillary second molar. The incidence of MB2 canal was 86.36% in maxillary first molars and 29.4% in maxillary second molars. 77.19 % of maxillary first molars and 90% of maxillary second molars had an unfilled MB2 canal. 72.7% of maxillary first molars and 88.8% of maxillary second molars showed significant periapical radiolucencies in unfilled MB2 canals. Conclusions MB2 canals were present in majority of cases and most of the unfilled MB2 canals showed evidence of periapical radiolucencies. Key words:MB2 Canals, Cone Beam computed Tomography (CBCT), Filled /Unfilled canals, Endodontically treated teeth. PMID:28149463

  18. 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...

  19. In vitro evaluation of the sealing ability of three newly developed root canal sealers: A bacterial microleakage study

    Science.gov (United States)

    Sobhani, Ehsan; Samadi-Kafil, Hossein; Pirzadeh, Ahmad; Jafari, Sanaz

    2016-01-01

    Background The purpose of this study was to compare the sealing ability of MTA Fillapex, Apatite Root Canal Sealer and AH26 sealers. Material and Methods The present in vitro study was carried out on 142 extracted single-rooted human mature teeth. The teeth were randomly divided into three experimental groups (n=44) and two control groups (n=5). Three root canal sealers were MTA Fillapex, Apatite Root Canal Sealer and AH26. The teeth in the control groups were either filled with no sealer or made completely impermeable. The root canals were prepared and obturated with gutta-percha and one of the sealers. The teeth were sterilized with ethylene oxide gas prior to the bacterial leakage assessment using Enterococcus faecalis. Leakage was evaluated every 24 hours for 90 days. Data were analyzed with descriptive statistical methods and chi-squared test. If the data were significant, a proper post hoc test was used. Statistical significance was set at P<0.05. Results The positive control specimens exhibited total bacterial penetration whilst the negative control specimens showed no evidence of bacterial penetration. At the end of the study, the analysis of microleakage with chi-squared test showed no significant differences between the experimental groups (P<0.05). The results of chi-squared test analyzing the pair-wise differences between the groups considering the numerical values for leakage day indicated the lowest leakage with AH26 and the highest with Apatite root sealer. Conclusions According to the results of the present study, sealing ability of AH26 was significantly higher than that of MTA Fillapex and Apatite Root Canal Sealer. Key words:Mineral Trioxide aggregate, root canal obturation, dental seal. PMID:27957271

  20. The ependyma of goat. II. Ependymal lining of the lateral ventricles, mesencephalic canal, and fourth ventricle: scanning electron microscopic study.

    Science.gov (United States)

    Rajtová, V

    1990-01-01

    The ependymal surface of the lateral cerebral ventricle, mesencephalic canal, and IVth ventricle of 13 male and female goats were studied by means of scanning electron microscopy. The lateral cerebral ventricle was covered mostly with thin cilia that might have club-like terminations on nucleus caudatus, the wide "naked" places with bleb-like protrusions occurred in the transition to cornu temporale during anestrous cycle. The ependymal surface of mesencephalic canal of female goats during anestrus was covered with abundant spherical protrusions. No other changes that could be related to the sexual differences were found.

  1. Management of distortion channels in the Cofrentes NPP; Gestion de la deformacion de canales en la central nuclear de Cofrentes

    Energy Technology Data Exchange (ETDEWEB)

    Albendea, J. C.; Garcia, P. J.; Iglesias, J.; Mascarell, R.

    2015-07-01

    Fuel channels distortion in BWR (Boiling Water Reactor) reactors may have implication for safety. This phenomenon is complex and, at the present time it is not known in detail. This article provides the Iberdrola Generacion Nuclear SAU ongoing activities to know, predict and mitigate the consequences that this phenomenon may cause in Cofrentes Nuclear Power Plant. (Author)

  2. 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.

  3. Comparative scanning electron microscopy evaluation of Canal Brushing technique, sonic activation, and master apical file for the removal of triple antibiotic paste from root canal (in vitro study

    Directory of Open Access Journals (Sweden)

    Deepa Ashoksingh Thakur

    2015-01-01

    Full Text Available Aims: To compare and evaluate the effectiveness of Canal Brushing technique, sonic activation, and master apical file (MAF for the removal of triple antibiotic paste (TAP from root canal using scanning electron microscopy (SEM. Materials and Methods: Twenty-two single rooted teeth were instrumented with ProTaper up to the size number F2 and dressed with TAP. TAP was removed with Canal Brush technique (Group I, n: 6, sonic (EndoActivator (Group II, n: 6, and MAF (Group III, n: 6. Four teeth served as positive (n: 2 and negative (n: 2 controls. The roots were split in the buccolingual direction and prepared for SEM examination (×1000 at coronal, middle, and apical third. Three examiners evaluated the wall cleanliness. Statistical Analysis: Statistical analysis was performed by Kruskal–Wallis test and Wilcoxon rank sum test. Results: Difference in cleanliness between three groups is statistically significant in cervical region only. Pairwise comparison in cervical region Canal Brush and sonic activation showed more removal of TAP than MAF. Conclusions: Canal Brush and sonic activation system showed better result than MAF in the cervical and middle third of canal. In the apical third, none of the techniques showed a better result. None of the techniques showed complete removal of TAP from the canal.

  4. Present and future in the use of micro-CT scanner 3D analysis for the study of dental and root canal morphology

    Directory of Open Access Journals (Sweden)

    Nicola M. Grande

    2012-01-01

    Full Text Available The goal of the present article is to illustrate and analyze the applications and the potential of microcomputed tomography (micro-CT in the analysis of tooth anatomy and root canal morphology. The authors performed a micro-CT analysis of the following different teeth: maxillary first molars with a second canal in the mesiobuccal (MB root, mandibular first molars with complex anatomy in the mesial root, premolars with single and double roots and with complicated apical anatomy. The hardware device used in this study was a desktop X-ray microfocus CT scanner (SkyScan 1072, SkyScan bvba, Aartselaar, Belgium. A specific software ResolveRT Amira (Visage Imaging was used for the 3D analysis and imaging. The authors obtained three-dimensional images from 15 teeth. It was possible to precisely visualize and analyze external and internal anatomy of teeth, showing the finest details. Among the 5 upper molars analyzed, in three cases, the MB canals joined into one canal, while in the other two molars the two mesial canals were separate. Among the lower molars two of the five samples exhibited a single canal in the mesial root, which had a broad, flat appearance in a mesiodistal dimension. In the five premolar teeth, the canals were independent; however, the apical delta and ramifications of the root canals were quite complex. Micro-CT offers a simple and reproducible technique for 3D noninvasive assessment of the anatomy of root canal systems.

  5. Present and future in the use of micro-CT scanner 3D analysis for the study of dental and root canal morphology.

    Science.gov (United States)

    Grande, Nicola M; Plotino, Gianluca; Gambarini, Gianluca; Testarelli, Luca; D'Ambrosio, Ferdinando; Pecci, Raffaella; Bedini, Rossella

    2012-01-01

    The goal of the present article is to illustrate and analyze the applications and the potential of microcomputed tomography (micro-CT) in the analysis of tooth anatomy and root canal morphology. The authors performed a micro-CT analysis of the following different teeth: maxillary first molars with a second canal in the mesiobuccal (MB) root, mandibular first molars with complex anatomy in the mesial root, premolars with single and double roots and with complicated apical anatomy. The hardware device used in this study was a desktop X-ray microfocus CT scanner (SkyScan 1072, SkyScan bvba, Aartselaar, Belgium). A specific software ResolveRT Amira (Visage Imaging) was used for the 3D analysis and imaging. The authors obtained three-dimensional images from 15 teeth. It was possible to precisely visualize and analyze external and internal anatomy of teeth, showing the finest details. Among the 5 upper molars analyzed, in three cases, the MB canals joined into one canal, while in the other two molars the two mesial canals were separate. Among the lower molars two of the five samples exhibited a single canal in the mesial root, which had a broad, flat appearance in a mesiodistal dimension. In the five premolar teeth, the canals were independent; however, the apical delta and ramifications of the root canals were quite complex. Micro-CT offers a simple and reproducible technique for 3D noninvasive assessment of the anatomy of root canal systems.

  6. ANATOMO-MORPHOLOGICAL FEUTURES OF THE ROOT CANAL SYSTEM IN GEORGIAN POPULATION - CONE-BEAM COMPUTED TOMOGRAPHY STUDY.

    Science.gov (United States)

    Beshkenadze, E; Chipashvili, N

    2015-10-01

    Incomplete and superficial knowledge of morphological types and anatomical variations of the root canal system will become the reason leading to the failure of endodontic treatment. cone-beam computed tomography (CBCT) - it is a technologically more sophisticated, interesting, reliable, non-invasive imaging technique with high degree of visualization, considered as a particularly important and useful tool to study complexity and variability of canal system. 2753 teeth of 228 patients have been studied by CT. Ages of the patients varied within 25-55 years. Among them 122 men and 106 women. Maxillary teeth - 1394 and mandibular - 1359, respectively. The aim of our study was investigation and evaluation of: tooth length, number of roots and canals, type of configuration, root canal curvature and degree of curvature in Georgian population. The results of the study revealed interesting data and anatomical characteristics, those replicating the racial signs and differs from the data recorded by the other researchers, became evident. In studying of dental form variations were interested anatomists (description and comparison) anthropologists, biologists, palaeontologists and stomatologists. The field of human dental anatomy has not been completely explored so, the modern human teeth still remain a matter of continual curiosity and research. The knowledge of anatomical characteristics of dental root canals will help clinicians to optimize the algorithm of endodontic treatment. Thus, statistic data are not the universal criterias, however, basing on these indicators anthropometrical data of roots and canals vary according to the geographic zones and nationalities. The study of variations in tooth form has interested anatomists (description and comparison), anthropologists, biologists, palaeontologists and dentists. The field of human dental anatomy has not been completely explored and the dentition of modern man still remains a matter of continual curiosity and research

  7. In Vitro Stereomicroscopic Study of the Incidence and Position of Root Canal Isthmuses in Mandibular First Molars

    Directory of Open Access Journals (Sweden)

    Tabrizizadeh

    2014-06-01

    Full Text Available Background Accessibility to all sites of root canal and its mechanical and chemical cleaning is mandatory for successful root canal therapy. The presence of isthmus is a major hindrance to complete root canal accessibility. Objectives The purpose of the present study was to determine the relative frequency and type of isthmuses in the apical region of mesial root of the first mandibular molar extracted in Yazd. Materials and Methods In this descriptive-laboratory study, 100 mandibular first molar teeth were collected. The mesial roots were excised at the cervical region and three horizontal sections perpendicular to the longitudinal axis of the root were secured with 1-, 3-, and 5-mm distances upwards from apex region of the roots. The incised surfaces were stained using India ink and viewed under stereomicroscope with a magnifying power of ×60 and photographed. The obtained images were studied regarding the presence or absence of isthmuses and the various anatomical forms of isthmuses were recorded based on Hsu and Kim taxonomy. Results Isthmus was present in 54% of teeth. The greatest frequency of isthmuses was observed in the 5 mm from the apex. The type V isthmus was the most prevalent isthmuses between all levels of roots. Conclusions The frequency of isthmuses in the mesial root of mandibular first molars was high. The results of clinical and surgical endodontic procedures may be affected by this aspect of root canal anatomy.

  8. DE CANALES

    Directory of Open Access Journals (Sweden)

    Roberto Carlos Guevara C.

    2013-01-01

    Full Text Available La amplia utilización de redes WiFi en los diversos escenarios sociales está generando una especie de saturación de canales, que a su vez ocasiona interferencia entre estas redes. Esta situación genera solapamiento de canales, lo que hace que las tasas de trasferencia se reduzcan. En este artículo se detalla esta situación, y se estructura y aplica un experimento para encontrarle solución al problema. También se presentan los resultados tabulados y graficados utilizando la herramienta de software libre inSSider.

  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. 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.

  11. A micro-computed tomography study of the negotiation and anatomical feature in apical root canal of mandibular molars.

    Science.gov (United States)

    Min, Yi; Ma, Jing-Zhi; Shen, Ya; Cheung, Gary Shun-Pan; Gao, Yuan

    2016-11-01

    The aim of this study was to investigate the clinical negotiation of various apical anatomic features of the mandibular first molars in a Chinese population using micro-computed tomography (micro-CT). A total of 152 mandibular first molars were scanned with micro-CT at 30 µm resolution. The apical 5 mm of root canal (ARC) was reconstructed three dimensionally and classified. Subsequently, the access cavity was prepared with the ARC anatomy blinded to the operator. The ARC was negotiated with a size 10 K file with or without precurve. Information on the ability to obtain a reproducible glide path was recorded. The anatomical classification of ARC was Type I with 68.45% in mandibular first molars. The negotiation result of ARC with Category i was 387 canals (74.00%). With a bent negotiating file, 96 canals were negotiated, including 88 reproducible glide paths (Category ii) and 8 irregular glide paths (Category iii). About 7.65% canals could not be negotiated with patency successfully (Category iv). The statistical analyze shown the anatomic feature of ARC had effect on the negotiation of ARC (p negotiation. The category of negotiation in ARC would be helpful in the using of NiTi rotary instruments. Negotiation of ARC to the working length with patency should be careful and skillful because of the complexities of ARC. SCANNING 38:819-824, 2016. © 2016 Wiley Periodicals, Inc.

  12. 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.

  13. Working Length Determination of Root Canal of Young Permanent Tooth: An In vitro Study

    Science.gov (United States)

    Diwanji, A; Rathore, AS; Arora, R; Dhar, V; Madhusudan, A; Doshi, J

    2014-01-01

    Background: Determination of correct working length is one of the keys to success in endodontic therapy. Aim: The aim of this study was to evaluate the diagnostic efficacy of various methods to determine working length of root canal. Materials and Methods: Tactile method was assessed using digital radiography and compared with electronic method using apex locator. A total sample of 30 single rooted young permanent teeth the (mandibular first premolars) with matured apices were selected for the study. Access cavity preparation was carried out. Working length was measured by tactile method using digital radiography and electronic method using apex locator with no 15 K file. Actual working length was established by grinding of cementum and dentine from the root apex and was observed under stereomicroscope. Data was collected and statistical analysis was carried out with the help of SPSS-15. Results: The results of this study showed that there was a significant difference between tactile method assessed by digital radiography and electronic method using apex locator. Conclusion: Apex locator was found to be more reliable and accurate when compared with the actual length. PMID:25221703

  14. 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.

  15. 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 ...

  16. 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

  17. 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.

  18. 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.

  19. Love canal questions

    Science.gov (United States)

    Bell, Peter M.

    The Environmental Protection Agency (EPA) conducted a 3-month monitoring study of the Love Canal area near Niagara Falls, N.Y., after the federal government pronounced that a potential health risk existed due to chemical waste dumps. In 1982 the Department of Health and Human Services (HHS) decided that the area was habitable, subject to implementation of effective safeguards against leakage from the canal and to cleaning up of the contaminants. Now, the Congressional Office of Technology Assessment (OTA) has announced that, with the information available, it is not possible to demonstrate with certainty that unsafe levels do not exist within the so-called “emergency declaration area” (EDA).

  20. 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

  1. 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.

  2. Study of Root Canal Anatomy in Human Permanent Teeth in A Subpopulation of Brazil's Center Region Using Cone-Beam Computed Tomography - Part 1.

    Science.gov (United States)

    Estrela, Carlos; Bueno, Mike R; Couto, Gabriela S; Rabelo, Luiz Eduardo G; Alencar, Ana Helena G; Silva, Ricardo Gariba; Pécora, Jesus Djalma; Sousa-Neto, Manoel Damião

    2015-10-01

    The aim of this study was to evaluate the frequency of roots, root canals and apical foramina in human permanent teeth using cone beam computed tomography (CBCT). CBCT images of 1,400 teeth from database previously evaluated were used to determine the frequency of number of roots, root canals and apical foramina. All teeth were evaluated by preview of the planes sagittal, axial, and coronal. Navigation in axial slices of 0.1 mm/0.1 mm followed the coronal to apical direction, as well as the apical to coronal direction. Two examiners assessed all CBCT images. Statistical data were analyzed including frequency distribution and cross-tabulation. The highest frequency of four root canals and four apical foramina was found in maxillary first molars (76%, 33%, respectively), followed by maxillary second molars (41%, 25%, respectively). The frequency of four root canals in mandibular first molars was 51%. Mandibular first premolars had two root canals and two apical foramina in 29% and 20% of the cases, respectively. Mandibular central and lateral incisors and canines presented two root canals in 35%, 42% and 22% of the cases, respectively. The navigation strategy in CBCT images favors a better identification of frequency and position of roots, root canals and apical foramina in human permanent teeth.

  3. 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.

  4. A comparative evaluation of electronic and radiographic determination of root canal length in primary teeth: An in vitro study

    Directory of Open Access Journals (Sweden)

    Iyer Satishkumar Krishnan

    2012-01-01

    Full Text Available Aims: The purpose of this in vitro study was to compare the root canal length determination by Electronic apex locator (EAL (Raypex 5 and conventional radiography, and then compare them with the actual measurements obtained by direct visualization. Settings and Design: This study was conducted at the Department of Pedodontics and Preventive Dentistry, Government Dental College, Thiruvananthapuram, Kerala, India. Subjects and Methods: One hundred single rooted primary teeth extracted due to extensive caries, trauma, serial extraction or unwillingness of the parent to save the teeth were selected. The teeth were numbered and root canal length was determined using the visual, electronic and the radiographic methods. The actual, electronic and the radiographic measurements were recorded. Statistical Analysis Used: Data were analyzed using Intraclass correlation test and linear regression analysis. Results: The accuracy of EAL and radiographic methods were 92% and 72%, respectively within + 0.5 mm. Both the electronic and conventional radiographic methods showed a high correlation and agreement (ICC intraclass correlation coefficient = 0.99 and 0.98 respectively with the actual measurements. Conclusions: EALs proved to be more accurate in determining the root canal length than the radiographic method.

  5. A comparative evaluation of electronic and radiographic determination of root canal length in primary teeth: An in vitro study

    Science.gov (United States)

    Krishnan, Iyer Satishkumar; Sreedharan, Sheela

    2012-01-01

    Aims: The purpose of this in vitro study was to compare the root canal length determination by Electronic apex locator (EAL) (Raypex 5) and conventional radiography, and then compare them with the actual measurements obtained by direct visualization. Settings and Design: This study was conducted at the Department of Pedodontics and Preventive Dentistry, Government Dental College, Thiruvananthapuram, Kerala, India. Subjects and Methods: One hundred single rooted primary teeth extracted due to extensive caries, trauma, serial extraction or unwillingness of the parent to save the teeth were selected. The teeth were numbered and root canal length was determined using the visual, electronic and the radiographic methods. The actual, electronic and the radiographic measurements were recorded. Statistical Analysis Used: Data were analyzed using Intraclass correlation test and linear regression analysis. Results: The accuracy of EAL and radiographic methods were 92% and 72%, respectively within + 0.5 mm. Both the electronic and conventional radiographic methods showed a high correlation and agreement (ICC intraclass correlation coefficient = 0.99 and 0.98 respectively) with the actual measurements. Conclusions: EALs proved to be more accurate in determining the root canal length than the radiographic method. PMID:23633801

  6. Electromagnetic studies of nuclear structure and reactions

    Science.gov (United States)

    Hersman, F. W.; Dawson, J. F.; Heisenberg, J. H.; Calarco, J. R.

    1990-06-01

    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.

  7. Efficiency of a semiconductor diode laser in disinfection of the root canal system in endodontics: An in vitro study

    Directory of Open Access Journals (Sweden)

    Mithra N Hegde

    2015-01-01

    Full Text Available Context: The success of endodontic treatment depends on the eradication of microbes from the rootcanal system and prevention of reinfection. The root canal is shaped with hand and rotary instruments under constant irrigation to remove the inflamed and necrotic tissue, microbes/biofilms, and other debris from the root canal space. The main goal of instrumentation is to facilitate effective irrigation, disinfection, and filling. Throughout the history of endodontics, endeavors have continuously been made to develop more effective irrigant delivery and agitation systems for root canal irrigation. Aim: The purpose of this study was to evaluate the efficacy of three different newer irrigation delivery techniques; namely Endovac, Stropko Irrigator, and laser disinfection with 5.25% sodium hypochlorite. Materials and Methods: Forty teeth after disinfection by Occupational Safety and Health Administration (OSHA regulations were instrumented and inoculated with bacterial strains of Enterococcusfaecalis. The teeth were divided into four groups, in the experimental group, the irrigants were delivered with the Endovac, Stropko Irrigator, and laser irradiation and the control group which received no irrigation. The samples were incubated in Muller-Hilton media plates and incubated for 24 h. Statistical analysis used: The colony forming units were determined and statistically analyzed using the chi-square test. Results: According to the results obtained, laser irradiation resulted in complete disinfection of the root canal system. The Endovac system resulted in significant disinfection as compared to the Stropko Irrigator system. Conclusion: Laser irradiation resulted in significantly higher antimicrobial effects compared with the Endovac and Stropko irrigation groups when in conjunction with sodium hypochlorite

  8. The Antibacterial Efficacy of Photo-Activated Disinfection, Chlorhexidine and Sodium Hypochlorite in Infected Root Canals: An in Vitro Study

    Science.gov (United States)

    Samiei, Mohammad; Shahi, Shahriar; Abdollahi, Amir Ardalan; Eskandarinezhad, Mahsa; Negahdari, Ramin; Pakseresht, Zahra

    2016-01-01

    Introduction: This study compared the efficacy of light-activated low-power laser, 2% chlorhexidine (CHX) and 2.5% NaOCl in eliminating Enterococcus faecalis (E. faecalis) from the root canal system. Methods and Materials: The root canals of 60 maxillary central incisors were contaminated with E. faecalis and then the bacteria were incubated for 24 h. All the root canals were instrumented in a crown-down manner with #4 and 3 Gates-Glidden drills, followed by RaCe rotary files (40/0.10, 35/0.08, and 30/0.06). The samples were randomly assigned to three experimental groups and one control group (n=15). In the control group no intervention was made. In the photo-activated disinfection (PAD) group, laser therapy was undertaken with diode laser beams (with an output power of 100 mW/cm2) for 120 sec. For the other two experimental groups, root canals were irrigated either with 5 mL of 2% CHX or 2.5% NaOCl solutions, respectively. The Kruskal-Wallis test was used to compare the CFU values of the bacteria and post-hoc Bonferroni test was used for pairwise comparisons. The level of significance was set at 0.05. Results: The inhibition of bacterial growth in all the experimental groups was significantly superior to the control group (Pfaecalis counts in comparison with the control group, but 2.5% NaOCl solution was the most effective protocol. PMID:27471527

  9. Phenotypic diversity in chondromyxoid fibroma reveals differentiation pattern of tumor mimicking fetal cartilage canals development: an immunohistochemical study.

    Science.gov (United States)

    Zustin, Jozef; Akpalo, Hana; Gambarotti, Marco; Priemel, Matthias; Rueger, Johannes M; Luebke, Andreas M; Reske, Dennis; Lange, Claudia; Pueschel, Klaus; Lohmann, Christoph; Rüther, Wolfgang; Amling, Michael; Alberghini, Marco

    2010-09-01

    Chondromyxoid fibroma represents a rare benign cartilaginous tumor of young patients occurring in a subcortical metaphyseal location. The histogenesis of chondromyxoid fibroma has not yet been postulated, even though the conventional histology and recent immunohistochemical studies on phenotype of the mesenchymal cells and extracellular matrix components suggested its origin in immature cartilage. Therefore, we wished to compare the morphological pattern of immature cartilage tissue with chondromyxoid fibroma to investigate a possible developmental counterpart of chondromyxoid fibroma. Archival paraffin-embedded tissues from 4 fetal femora and 10 cases of chondromyxoid fibroma were analyzed simultaneously using histochemistry (safranin O) and established immunohistochemical antibodies (CD34, CD163, and smooth muscle actin). Vascularized cartilage canals growing into the fetal cartilage from the perichondrium displayed characteristic glomeruloid structures with central arterioles within the immature mesenchymal stroma and numerous superficial sinusoidal blood vessels accompanied by macrophage infiltration. Similarly, each case of chondromyxoid fibroma demonstrated admixture of two characteristic components: immature fibrous tissue of vascularized stroma with accumulation of macrophages in areas of superficial sinusoidal proliferation, and variable amounts of lobulated chondroid tissue. Based on the observed substantial morphological similarity between the cartilage canals and chondromyxoid fibroma, we suggest that the chondromyxoid fibroma represents a neoplasm originating from or mimicking the fetal cartilage canals within the immature cartilage.

  10. 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.

  11. Frequency, Impact, and Predictors of Persistent Pain Following 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

    2015-01-01

    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. While biopsychosocial mechanisms are thought to be associated with the development of such pain, similar to persistent pain following surgery in other body sites, little is known about the baseline predictors for persistent pain. We assessed the frequency of persistent pain 6 months following RCT, measured the impact this pain had on patients, and determined predictive factors for persistent tooth pain in a multi-center 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 following RCT. On average, these patients reported their pain as mild to moderate in intensity, present for about 10 days in the preceding month, and minimally interfered with daily activities. After adjusting for type of dental practitioner and patient age, gender and household income, pain duration over the week prior to RCT significantly increased the risk of developing persistent pain (odds ratio [OR]=1.19 per 1 day increase in pain duration, 95% confidence interval [CI]: 1.07–1.33), whereas optimism about the procedure reduced the risk (OR=0.39, 95% CI: 0.22–0.67). Our data suggest that persistent pain following 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, while pre-operative pain duration and the patient’s expectation did. PMID:26335907

  12. 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.

  13. 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

  14. 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.

  15. An experimental study on the frog semicircular canal--functions of cupula and vestibular ganglion.

    Science.gov (United States)

    Suzuki, M; Harada, Y

    1985-02-01

    An isolated frog posterior semicircular canal was stimulated either by mechanical or thermal endolymphatic flow. Ampullofugal stimulation induced action potentials from the posterior ampullary nerve. These potentials adapted in six to eight seconds. While mechanical endolymphatic flow was induced, the cupula maintained its shift position without swinging back to the neutral point. This indicates that adaptation is mainly of sensorineural origin. When the canal was stimulated by a piece of frozen Ringer's solution, an increase in spike discharge was observed. The responses from the vestibular nerve trunk were compared to those from the posterior ampullary nerve. The time course of the response was shorter and the maximum spike count was smaller in the recordings from the vestibular nerve trunk.

  16. Study on nuclear power introduction into Vietnam

    Energy Technology Data Exchange (ETDEWEB)

    Vuong Huu Tan [Vietnam Atomic Energy Commission, 59 Ly Thuong Kiet, Hanoi (Viet Nam)

    2000-03-01

    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)

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

    Directory of Open Access Journals (Sweden)

    Suroopa Das

    2015-01-01

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

  18. 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.

  19. 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.

  20. Ependyma of the central canal of the rat spinal cord: a light and transmission electron microscopic study.

    Science.gov (United States)

    Bruni, J E; Reddy, K

    1987-06-01

    Ependymal cells of the rat central canal were examined with a view to identifying features that distinguish them regionally and from their counterparts elsewhere in the ventricular system. The results revealed that the lining consisted for the most part of a pseudostratified layer of uniformly organised cuboidal to columnar ependymal cells present in largest numbers in lumbar and sacral segments and in the conus. Two cell variants were identified on the basis of the presence or absence of a radially directed cytoplasmic process originating from the base of the cell. The tanycytic form of ependymal cell was encountered along the entire length of the central canal but with increased frequency in caudalmost segments. Ependymal cells were largely similar in ultrastructural appearance along the length of the cord. Although they were also similar in appearance and orientation to their counterparts in the ventricles they did exhibit some unique features. The most notable were the prominent junctional complexes and associated filaments present along the lateral border of the cells near their apex and the abundance of intermediate filaments in tanycytes. The central canal of the filum differed most markedly from other segments of the cord and resembled in structure the primitive ependymal tube of the caudal cord in lower vertebrates. Ependymal cells of the cord were not sufficiently dissimilar morphologically from their counterparts in the ventricles to account for differences in proliferative capacity in response to localised injury. A factor that merits further study is the difference in numbers of tanycyte ependymal cells in the two locations for they may be the reactive elements that proliferate in response to injury.

  1. The Love Canal: Beyond science?

    Science.gov (United States)

    Bell, Peter M.

    When in 1978, the New York State Department of Health issued the report, ‘Love Canal—Public Health Time Bomb,’ the serious effects of chemical waste contamination in the Love Canal area became an issue of national concern. A few ‘studies’ since then have produced results in concert with those of initial reports that described ‘conditions of acute health effects’ as being linked to hazardous wastes incorporated in landfill in the Love Canal site near Niagara Falls, New York. Now that a ‘blue ribbon’ panel of experts from the medical sciences has reviewed the problems of Love Canal, however, a different view has emerged. The ‘Report of the Governors' Panel to Review Scientific Studies and the Development of Public Policy on Problems Resulting from Hazardous Wastes,’ transmitted in October of this year, identifies the following factors about the health effects at Love Canal:

  2. Comparative evaluation of a novel smart-seal obturating system and its homogeneity of using cone beam computed tomography: In vitro simulated lateral canal study

    Directory of Open Access Journals (Sweden)

    Shashank Arora

    2014-01-01

    Full Text Available Aim: The aim was to evaluate and compare a novel polyamide polymer based obturating system and Gutta-percha and sealer in filling simulated lateral canals and their homogeneity when used for obturating the root canals. Materials and Methods: A total of 60 freshly extracted human single rooted teeth with fully formed apices were selected for this study. Teeth were de-coronated, and roots were standardized to a working length of 15 mm. Root canal preparation was carried out with rotary Protaper file system in all groups. The specimens were then randomly divided into three groups A, B, and C (n = 20. Ten samples from each group were decalcified and simulated lateral canals were made at 2, 4, and 6 mm from the root apex. Remaining ten samples from each group were maintained calcified. Group A was obturated with SmartSeal system (Prosmart-DRFP Ltd., Stamford, UK. Group B was obturated with sectional backfill method. Group C was obutrated with cold lateral compaction method (control. Decalcified samples from the respective groups were analyzed with digital radiography and photography and the measurement of the linear extension and area of lateral canal filling was done using UTHSCSA (UTHSCSA Image Tool for Windows version 3.0, San Antonio, TX, USA software. Calcified samples were subjected to cone beam computed tomography image analysis sectioned axially. Results: Group A 92.46 ± 19.45 showed greatest extent of filling in lateral canals and denser homogeneity of oburation, followed by Group B 78.43 ± 26.45 and Group C 52.12 ± 36.67. Conclusions: Polyamide polymer obturation proved to have greater efficiency when compared with Gutta-percha system, when used for obturation with regards to adaptation of the sealer and penetration into the simulated lateral canals.

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

    Energy Technology Data Exchange (ETDEWEB)

    Lee, U. J.; Han, K. W.; Jeon, P. I.; Kim, Y. T.; Nam, Y. M.; Won, J. Y.; Kim, H. K. [KAERI, Taejon (Korea, Republic of)

    2004-07-01

    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.

  4. Study of the injury risk to the mandibular canal bycone beam computed tomography images

    OpenAIRE

    Leandro Scomparin

    2013-01-01

    O conhecimento anatômico da mandíbula, do canal mandibular e outros reparos presentes na região mandibular são essenciais para o sucesso em vários procedimentos odontológicos, variando desde o mais básico como a anestesia, até procedimentos mais complexos, tais como a instalação de implantes, cirurgias ortognáticas e até mesmo cirurgias para correções estéticas de ângulo mandibular. O objetivo deste trabalho foi analisar as distâncias presentes da cortical vestibular mandibular, até a cortica...

  5. Coupled Cluster studies of infinite nuclear matter

    CERN Document Server

    Baardsen, G; Hagen, G; Hjorth-Jensen, M

    2013-01-01

    The aim of this work is to develop the relevant formalism for performing Coupled Cluster calculations in nuclear matter and neutron star matter, including thereby important correlations to infinite order in the interaction and testing modern nuclear forces based on chiral effective field theory. Our formalism includes the exact treatment of the so-called Pauli operator in a partial wave expansion of the equation of state. Nuclear and neutron matter calculations are done using a coupled particle-particle and hole-hole ladder approximation. The coupled ladder equations are derived as an approximation of CC theory, leaving out particle-hole and non-linear diagrams from the CC doubles amplitude equation. This study is a first step toward CC calculations for nuclear and neutron matter. We present results for both symmetric nuclear matter and pure neutron matter employing state-of-the-art nucleon-nucleon interactions based on chiral effective field theory. We employ also the newly optimized chiral interaction [A. E...

  6. CBCT法研究上颌第一磨牙根管形态%Cone beam computed tomography study of the root canal morphology of maxillary first molars

    Institute of Scientific and Technical Information of China (English)

    刘海霞; 马胤喆

    2016-01-01

    目的:探讨应用锥形束CT研究上颌第一磨牙牙根及根管形态的价值。方法选取70例患者83颗上颌第一磨牙的锥形束CT(cone beam computed tomogaphy,CBCT)影像,分析其牙根数目、根管数目及根管系统的解剖结构。参照Vertucci分类法对根管形态进行分类,统计近中颊根第二根管(the seconal mesiobuual canal, MB2)率。结果83颗上颌第一磨牙均为3个独立牙根,其中MB2的发生率为38.6%,近中颊根根管VertucciⅠ型(1⁃1)、Ⅳ型(2⁃2型)、Ⅱ型(2⁃1)、Ⅲ型(1⁃2⁃1)所占百分比分别为61.4%、18.1%、15.7%和4.8%。结论上颌第一磨牙根管系统复杂,CBCT影像可反映真实根管形态,为根管治疗提供参考。%Objective To study the value of the application of cone beam CT on the research of root canal morphol⁃ogy of maxillary first molars. Methods Eighty⁃three maxillary first molars of 70 patients were randomly selected in this study. All teeth were examined for morphology of roots and root canals by cone beam computed tomography (CBCT). The root canals configuration was classified using Vertucci��s classification. The incidence of second mesiobuccal canal (MB2) was calculated. Results All of the maxillary first molars had three separated roots. The incidence of MB2 canal was 38.6%. In the mesiobuccal roots, the most common Vertucci classifications of canal types were typeⅠ(1⁃1, 61.4%), typeⅣ(2⁃2, 18.1%), typeⅡ(2⁃1, 15.7%), typeⅢ(1⁃2⁃1, 4.8%). Conclusion The root canal system of maxillary first molars is complicated. CBCT images can facilitate the identification of root canal and provide reference for the root ca⁃nal treatment.

  7. Spent Nuclear Fuel Transport Reliability Study

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jy-An John [ORNL; Wang, Hong [ORNL; Jiang, Hao [ORNL

    2016-01-01

    This conference paper was orignated and shorten from the following publisehd PTS documents: 1. Jy-An Wang, Hao Jiang, and Hong Wang, Dynamic Deformation Simulation of Spent Nuclear Fuel Assembly and CIRFT Deformation Sensor Stability Investigation, ORNL/SPR-2015/662, November 2015. 2. Jy-An Wang, Hong Wang, Mechanical Fatigue Testing of High-Burnup Fuel for Transportation Applications, NUREG/CR-7198, ORNL/TM-2014/214, May 2015. 3. Jy-An Wang, Hong Wang, Hao Jiang, Yong Yan, Bruce Bevard, Spent Nuclear Fuel Vibration Integrity Study 16332, WM2016 Conference, March 6 10, 2016, Phoenix, Arizona.

  8. Nuclear Proliferation: A Unit for Study.

    Science.gov (United States)

    Fernekes, William R.

    1990-01-01

    Using Argentina as a sample case study, presents a classroom unit designed to explain the implications for world peace of nuclear weapons development. Employs a policy analysis model to make an indepth examination of the values underlying all government policy decisions. Includes unit topics and procedures for the exercise. (NL)

  9. An in vitro comparative study of intracanal fluid motion and wall shear stress induced by ultrasonic and polymer rotary finishing files in a simulated root canal model.

    Science.gov (United States)

    Koch, Jon; Borg, John; Mattson, Abby; Olsen, Kris; Bahcall, James

    2012-01-01

    Objective. This in vitro study compared the flow pattern and shear stress of an irrigant induced by ultrasonic and polymer rotary finishing file activation in an acrylic root canal model. Flow visualization analysis was performed using an acrylic canal filled with a mixture of distilled water and rheoscopic fluid. The ultrasonic and polymer rotary finishing file were separately tested in the canal and activated in a static position and in a cyclical axial motion (up and down). Particle movement in the fluid was captured using a high-speed digital camera and DaVis 7.1 software. The fluid shear stress analysis was performed using hot film anemometry. A hot-wire was placed in an acrylic root canal and the canal was filled with distilled water. The ultrasonic and polymer rotary finishing files were separately tested in a static position and in a cyclical axial motion. Positive needle irrigation was also tested separately for fluid shear stress. The induced wall shear stress was measured using LabVIEW 8.0 software.

  10. Juvenile Salmonid Pit-Tag Studies at Prosser Dam and the Chandler Canal Fish Collection Facility, Yakima River, 1991 and 1992 Final Report.

    Energy Technology Data Exchange (ETDEWEB)

    Ruehle, Thomas E.; Sandford, Benjamin P.

    1996-01-01

    In 1991 and 1992, the National Marine Fisheries Service completed the second and third years of a 3-year study to estimate juvenile salmonid (Oncorhynchus spp.) timing and survival characteristics related to passage through the Prosser Dam complex, including the Chandler Canal and the Chandler fish collection facility, on the Yakima River. Yearling chinook (O. tshawyacha) and coho salmon (O. kisutch) were collected at the Chandler facility, PIT tagged, and released at various locations in the Yakima River, Chandler Canal, and the Chandler facility. Individual fish were subsequently detected at PIT-tag detection monitors at the Chandler facility and/or McNary Dam on the Columbia River. Survival through various reaches, PIT-tag detection efficiency, and Chandler Canal fish entrainment proportion parameters were estimated using maximum likelihood techniques. The research objectives in 1991 and 1992 were to: (1) assess the effects of passage through the Chandler Canal and the Chandler facility on the survival of juvenile salmonids, (2) determine the entrainment rate of juvenile salmonids into the Chandler Canal as a function of river flow, and (3) determine the efficiency and reliability of the PIT-tag monitoring system at the Chandler facility. The initial 1990 research plan was expanded in 1991 and 1992 to include several more release locations and many more release days.

  11. Estudio vascular renal por TC multidetector de 64 canales 64-Multidetector row CT for the Renal Vascular Study

    Directory of Open Access Journals (Sweden)

    Daniela Stoisa

    2009-03-01

    Full Text Available Objetivo: Mostrar las diversas variantes anatómicas vasculares tanto arteriales como venosas en el estudio angiográfico renal por tomografìa computada multidetector (TCMD de 64 canales, dada su implicancia en un eventual planeamiento quirúrgico. Material y métodos: Evaluamos retrospectivamente 26 estudios realizados con tomógrafo Philips Brilliance de 64 canales. Se obtuvieron secuencias sin contraste y postcontraste e.v. en fases arterial y venosa, administrado con bomba inyectora doble cabezal. Para una fase arterial apropiada se utilizó técnica de bolus track. Las imágenes fueron posteriormente procesadas en Workstation Philips Brilliance 190P en un tiempo promedio de 30 minutos y reconstruidas con técnicas MIP y volumétrica. Resultados: Dentro de las variantes anatómicas arteriales, encontramos: bifurcaciones prehiliares (n=3, arterias accesorias (n=4 y arterias polares (n=9. Dentro de las variantes venosas fueron halladas: venas renales múltiples (n=5, venas circumaórticas (n=2, retroaórticas (n=2 y vena tributaria lumbar prominente (n=1. Conclusión: El estudio vascular renal adquiere importancia en el planeamiento quirúrgico en casos de nefrectomías parciales, laparoscópicas y en el transplante renal. Esto otorga suma utilidad al estudio de TCMD de 64 canales por su eficacia diagnóstica, dada la alta calidad de las reconstrucciones obtenidas, llegando a igualar a la angiografía digital, sin ser un método invasivo.Purpose: To show the wide range of anatomical vascular variants, arterial and venous, that can be seen in the angiographic renal study using 64-multidetector-row computed tomography (64-MDCT, due to its importance in an eventual surgical planning. Material and Methods: We have evaluated retrospectively 26 studies that have been done using a 64 channels Philips Brilliance CT scanner. We have obtained non enhanced and both in arterial and venous enhanced sequences. For the injection of the contrast material we

  12. 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...... imaging (MRI) scans were performed during upright standing and supine positions with and without axial load. In section 2, MRI scans were performed exclusively in supine positions, one with flexion of the lumbar spine (psoas-relaxed position), an extended position (legs straight), and an extended position...... of precautions taken to secure immobility during the vertical scans. This seemingly makes our standing posture less valuable as a standard of reference. In section 2, DCSA was reduced at all 5 lumbar levels after extension, and further reduced at 2 levels after adding compression (P

  13. Detection of hypoplasia of bony cochlear nerve canal by virtual endoscopy: a pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Quan Yong; Wu Lebin; Gong Wuxian; Gong Ruozhen (Shandong Medical Imaging Research Institute, Shandong Univeristy, Jinan, Shandong (China)), email: grzh99@yahoo.com.cn; Zu Zushan (Dept. of Radiology, Wendeng Central Hospital, Weifang Medical College, Weihai (China))

    2011-09-15

    Background: Dimensions of the bony cochlear nerve canal (BCNC) have been proposed as a potential diagnostic standard for hypoplasia of BCNC, but the standard remains inconsistent. We have previously found that a helix-like shape appears in normal BCNCs at VE images, whereas, the sign does not appear in some hypoplastic BCNCs. Purpose: To retrospectively examine the feasibility of computed tomographic (CT) virtual endoscopy (VE) in the evaluation of hypoplasia of BCNC on the basis of absence of a helix-like shape. Material and Methods: Twenty ears in 14 consecutive patients (mean age 5.5 years, range 1-15 years, 6 boys, 8 girls) diagnosed with hypoplasia of BCNC were included in this work. One hundred ears in 50 gender- and age-matched individuals (mean age 6.6 years, range 1-15 years, 29 boys, 21 girls) without inner ear disease and internal auditory canal (IAC) malformations served as controls. The presence or absence of a helix-like shape was evaluated by two independent reviewers. The value of VE for the diagnosis of hypoplasia of BCNC was assessed with clinical results and routine radiologic evaluation as the reference standard. Inter-observer agreement was calculated. Sensitivity, specificity, and accuracy were selected to test the diagnostic ability of the VE. Results: Absence of a helix-like shape was found in the cochlear area of 17 of 20 ears in patients with hypoplasia of BCNC but in none of the control subjects. Inter-observer agreement was substantial (? = 0.773). The diagnostic rates of absence of a helix-like shape for hypoplasia of BCNC in terms of sensitivity, specificity, and accuracy were 85%, 100%, and 98%, respectively. There were significant differences between the two groups with respect to VE findings for absence of a helix-like shape (P < 0.001). Conclusion: The absence of a helix-like shape at VE images may be used as a potentially useful sign in the diagnosis of hypoplasia of BCNC

  14. Nested Canalizing Functions and Their Networks

    CERN Document Server

    Kadelka, Claus; Adeyeye, John O; Laubenbacher, Reinhard

    2014-01-01

    The concept of a nested canalizing Boolean function has been studied over the last decade in the context of understanding the regulatory logic of molecular interaction networks, such as gene regulatory networks. Such networks are predominantly governed by nested canalizing functions. Derrida values are frequently used to analyze the robustness of a Boolean network to perturbations. This paper introduces closed formulas for the calculation of Derrida values of networks governed by Boolean nested canalizing functions, which previously required extensive simulations. Recently, the concept of nested canalizing functions has been generalized to include multistate functions, and a recursive formula has been derived for their number, as a function of the number of variables. This paper contains a detailed analysis of the class of nested canalizing functions over an arbitrary finite field. In addition, the concept of nested canalization is further generalized and closed formulas for the number of such generalized fun...

  15. 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

  16. An in-vitro comparative study for assessment of apical sealing ability of Epiphany/AH Plus sealer with Resilon/gutta-percha root canal filling materials

    Science.gov (United States)

    Sultana, Meraj; Musani, Mohammad A.; Ahmed, Iffat M.

    2016-01-01

    Aims and Objectives: Endodontic treatment is directed to eliminate microbial challenges from the root canal system and to create a complete seal. The aim of this study was to assess the apical sealing ability of resin-based Epiphany-Resilon root canal filling system and to compare it with the sealing abilities of different combinations of AH Plus, gutta-percha, Epiphany, and Resilon. Materials and Methods: One hundred extracted human maxillary incisor roots were treated endodontically. The samples were divided into groups A, B, C, and D, with each group containing 25 samples. Group A: Canals obturated with gutta-percha and AH Plus sealer; Group B: Canals obturated with Resilon and Epiphany; Group C: Canals obturated with gutta-percha and Epiphany; Group D: Control group canals obturated with gutta-percha without a sealer. The sealing ability of each of the obturation techniques was tested using the dye penetration method followed by the clearing method using alcohol. Stereo microscope was used to measure the extent of dye penetration. Statistical data analysis was performed using analysis of variance and Tukey tests. Results: Microleakage was found in all the four groups. Apical extent of mean microleakage was maximum for gutta-percha, followed by Gutta-percha + AH-plus and Gutta-percha + Epiphany, and the least with Resilon + Epiphany. Statistically significant difference (P < 0.01) was seen in the apical leakage. Conclusion: All the samples tested showed microleakage. The “Epiphany soft resin endodontic obturation system” showed a superior result compared to other obturation materials. PMID:27583220

  17. Comparison of calcium hydroxide removal by self-adjusting file, EndoVac, and CanalBrush agitation techniques: An in vitro study

    Directory of Open Access Journals (Sweden)

    Sevinç Aktemur Türker

    2013-01-01

    Full Text Available Objectives: This study comparatively evaluated the efficacy of self-adjusting file (SAF, Endovac, and CanalBrush irrigant agitation protocols in removing calcium hydroxide (Ca(OH 2 from the root canals. Materials and Methods: Sixty extracted human mandibular canine teeth were instrumented with ProTaper rotary instruments to size #40 and dressed with Ca(OH 2 . The roots were randomly assigned to four groups according to irrigant agitation protocol used (n = 15. In Group 1: Conventional syringe irrigation (no activation, control; Group 2: Rotary brush agitation (CanalBrush; Group 3: Apical negative pressure irrigation (EndoVac system; and Group 4: Sonic agitation (SAF were used. Scanning electron microscopic (SEM evaluation was done for assessment of Ca(OH 2 removal in the coronal and apical thirds. Statistical analysis was performed by Wilcoxon and Kruskal-Wallis tests. Results: There were statistically significant differences among the groups (P = 0.218. A statistically significant difference was seen between the test groups in Ca(OH 2 removal from the apical third of the canal (P 0.05. The most efficient Ca(OH 2 removal in apical third was recorded in Group 3 (EndoVac and Group 4 (SAF (P < 0.05. In Group 4 (sonic agitation, there was no significantly difference between Ca(OH 2 removal in coronal and apical thirds. Conclusions: SAF and EndoVac showed significantly better performance than CanalBrush and conventional syringe irrigation in removing Ca(OH 2 from apical third of the root canals.

  18. Modelling of Buckingham Canal water quality.

    Science.gov (United States)

    Abbasi, S A; Khan, F I; Sentilvelan, K; Shabudeen, A

    2002-10-01

    The paper presents a case study of the modelling of the water quality of a canal situated in a petrochemical industrial complex, which receives wastewaters from Madras Refineries Limited (MRL), and Madras Fertilizers Limited (MFL). The canal well known Buckingham Canal which passes through Chennai (Madras), India has been modelled using the software QUAL2E-UNCAS. After testing and validation of the model, simulations have been carried out. The exercise enables forecasting the impacts of different seasons, base flows, and waste water inputs on the water quality of the Buckingham Canal. It also enables development of water management strategies.

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

    Energy Technology Data Exchange (ETDEWEB)

    Do Nascimento, Eduarda Helena Leandro [Dept. of Oral Diagnosis, Division of Oral Radiology, Piracicaba Dental School, University of Campinas (UNICAMP), Sao Paulo (Brazil); Ddos Anjos Pontual, Maria Luiza; Dos Anjos Pontual, Andra; Da Cruz Perez, Danyel Elias; De Moraes Ramos-Perez, Flavia Maria [Dept. of Clinical and Preventive Dentistry, School of Dentistry, Federal University of Pernambuco (UFPE), Pernambuco (Brazil); Figueiroa, Jose Natal [Instituto de Medicina Integral Professor Fernando Figueira - IMIP, Pernambuco (Brazil); Frazao, Marco Antonio Gomes [Dept. of Oral Radiology, Recife Dental School (FOR), Pernambuco (Brazil)

    2016-06-15

    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). 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. 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). 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.

  20. 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.

  1. 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.

  2. Progress report on nuclear spectroscopic studies

    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 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.

  3. 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...

  4. Underground nuclear astrophysics studies with CASPAR

    Directory of Open Access Journals (Sweden)

    Robertson Daniel

    2016-01-01

    Full Text Available 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,n16O and 22Ne(α,n25Mg 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

  5. 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

  6. Nuclear analytical techniques in environmental studies.

    Science.gov (United States)

    Jervis, R E

    1994-01-01

    Nuclear analytical techniques are particularly suitable for measuring trace components in a wide variety of environmental samples, and for that reason, the techniques have made a significant contribution to environmental research. Presently, at a time when biosphere contamination and threats of global change in the atmosphere are of widespread concern, there exist an impressive array of specialized instrumental methods available to life scientists engaged in environmental studies; however, the nuclear techniques will probably continue to play a useful role in the future, notwithstanding the decreasing availability of necessary facilities, such as research reactors and accelerators. Reasons for the particular suitability of radionanalytical techniques are reviewed and illustrated by examples of recent applications to solid wastes, biomonitoring, and urban aerosol source identification in this laboratory.

  7. Electromagnetic studies of nucleon and nuclear structure

    Energy Technology Data Exchange (ETDEWEB)

    Heisenberg, J.H.; Calarco, J.R.; Hersman, F.W.; Dawson, J.F.

    1993-06-01

    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 {sup 12}C and {sup 16}O are reported, as well as work on nuclear structure models and instrumentation development.

  8. Controversy at Love Canal.

    Science.gov (United States)

    Paigen, B

    1982-06-01

    A cancer researcher reviews the events surrounding the toxic waste contamination at Love Canal with emphasis on the political nature of the controversy about its health impact. Antagonism between the community and the New York State Department of Health was fueled by several factors: the state's awareness that it gained from delay in investigation, disagreement on health problems to be studied, control over the information gathering process, silencing of opposition opinion, and the violation of norms of scientific behavior. The author calls for the establishment of standards of ethical behavior for scientists in such situations, standards for conflict resolution, and means of appeal for those injured.

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-01-01

    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.)

  10. Long-term results of external auditory canal closure and mastoid obliteration in cochlear implantation after radical mastoidectomy: a clinical and radiological study.

    Science.gov (United States)

    Vincenti, Vincenzo; Pasanisi, Enrico; Bacciu, Andrea; Bacciu, Salvatore

    2014-08-01

    Cochlear implant candidates with mastoid cavity present a significant challenge to safe cochlear implantation because of possible spread of infection to the inner ear as well as an increased risk of electrode array extrusion. Closure of the external auditory canal is one of the several surgical techniques utilized to block the potential entry routes for infection and to protect the implanted device. The main concern after external auditory canal closure is the risk of developing a cholesteatoma, which can lead to an asymptomatic erosion of the temporal bone and/or cochlear implant failure. In this study we present the results of very long-term (mean 12 years) clinical and radiological follow-up in 12 patients who underwent external auditory canal closure associated with mastoid and Eustachian tube obliteration to facilitate cochlear implantation. To date, with a mean ± SD follow-up of 12 ± 4.7 years (range 5-21 years), the only complication experienced was the breakdown of the EAC closure in one patient, successfully treated by performing a rotation skin flap. The results of this study confirmed that external auditory canal closure is a reliable technique in cochlear implantation after radical mastoidectomy provided that a rigorous surgical technique is performed. A right balance between the need to reduce costs and to avoid unnecessary doses of radiation to patients and the task of a radiological surveillance may be represented by performing computed tomography 12-18 months postoperatively and then, only if clinically warranted.

  11. 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.

  12. Benign Paroxysmal Positional Vertigo with Simultaneous Involvement of Multiple Semicircular Canals

    OpenAIRE

    Shim, Dae Bo; Song, Chang Eun; Jung, Eun Jung; Ko, Kyung Min; Park, Jin Woo; Song, Mee Hyun

    2014-01-01

    Background and Objectives Benign paroxysmal positional vertigo (BPPV) generally involves a single semicircular canal (single canal BPPV) but it has been reported that more than one semicircular canal on either the same or the opposite side can be involved in 6.8-20% of the cases (multiple canal BPPV). In this study, the clinical characteristics of multiple canal BPPV were analyzed and compared to those of single canal BPPV. Materials and Methods Retrospective analysis was performed on 1054 co...

  13. 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.

  14. Comparison of Antibacterial Effects of 810 and 980- nanometer Diode Lasers on Enterococcus Faecalis in the Root Canal System -An in vitro study.

    Science.gov (United States)

    Asnaashari, Mohamad; Ebad, Leila Tahmasebi; Shojaeian, Shiva

    2016-10-01

    Background and aim: Use of laser technology in endodontics has greatly increased in the recent years due to the introduction of new wavelengths and methods and optimal antimicrobial and smear layer removal properties of lasers. This in vitro study aimed to compare the antibacterial effects of diode lasers of 810 nm and 980 nm wavelength on Enterococcus faecalis (E. faecalis) biofilm in the root canal system. Materials and methods: Fifty single-canal human anterior teeth were cleaned, shaped, sterilized and randomly divided into four groups namely two experimental, one positive and one negative control group. The experimental and positive control groups were inoculated with E. faecalis and incubated for two weeks. The experimental group one (n=20) received 810 nm diode laser irradiation (1.5W) while the experimental group two (n=20) was subjected to 980 nm diode laser irradiation (1.5W). The E. faecalis colony forming units (CFUs) were counted in each root canal before and after laser irradiation. Results: Laser irradiation significantly decreased the bacterial colony count in both experimental groups. The reduction in microbial count was significantly greater in 810 nm laser group compared to 980 nm laser group. Conclusion: Irradiation of both 810 and 980 nm lasers significantly decreased the E. faecalis count in the root canal system; 810 nm laser was more effective in decreasing the intracanal microbial load.

  15. 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...

  16. Comparative evaluation of debris removal from root canal wall by using EndoVac and conventional needle irrigation: An in vitro study

    Directory of Open Access Journals (Sweden)

    Vandana J Gade

    2013-01-01

    Full Text Available Context: Microbial control is of paramount importance in Clinical Endodontics. Therefore, cleaning and disinfection of root canals are essential to achieve endodontic success. Aims: The purpose of this study is to compare the efficacy of EndoVac irrigation system and conventional needle (30 gauges side venting needle irrigation for removal of debris from the root canal walls at coronal, middle and apical third by using the scanning electron microscopy (SEM. Settings and Design: An in vitro randomized control trial study. Materials and Methods: A total of 20 mandibular premolars with completely formed roots were selected and randomly divided into two groups - Group 1: Irrigation with the Conventional system and Group 2: EndoVac irrigation. After access opening and working length determination biomechanical preparation completed up to a rotary protaper F4 file. Groupwise irrigation with sodium hypochlorite and ethylenediaminetetraacetic acid was done with each canal in between instrumentation. Then, the teeth were sectioned in buccolingual direction and the halves were sputter-coated with gold palladium and coronal, middle and apical third were examined by SEM at x2000 magnification. Statistical Analysis: Mann-Whitney test for comparison between methods, Kruskal-Wallis test for comparison among thirds and Miller test for individual comparisons. Results: The apical, middle and cervical root canal thirds were evaluated and the results were analyzed statistically by the Mann-Whitney test for comparison between methods, Kruskal-Wallis test for comparison among thirds and Miller test for individual comparisons. Conclusions: EndoVac group resulted in significantly less debris at apical third compared with the conventional needle irrigation group. There was no statistical significant difference found in debris removal at coronal and middle third of root canal wall between the EndoVac group and conventional needle irrigation group.

  17. 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.

  18. Clinical Value of Nuclear Magnetic Resonance Imaging in Diagnosis of Spinal Canal Tumors%核磁共振对椎管肿瘤诊断的临床价值评价

    Institute of Scientific and Technical Information of China (English)

    周航; 王晖; 王全; 刘宁

    2016-01-01

    目的:研究核磁共振对于椎管肿瘤的诊断价值。方法针对我院诊治的60位有椎管肿瘤患者,在手术之前进行核磁共振检测,在手术当中进行病理检测,对两组检测方法的准确性进行对比分析。结果对于60位患者诊断出血管母细胞瘤1位,呈型细胞瘤14位,神经细胞瘤3位,转移瘤11位,脊膜瘤11位,室管膜瘤8位,精神纤维瘤6位,脂肪瘤6位,手术当中进行病理检测于上述结果一致。结论磁共振对于椎管肿瘤的确诊有良好的效果,并且操作简便,对患者的伤害小。%Objective To study the value of nuclear magnetic resonance imaging in diagnosis of spinal canal tumors.Methods 60 patients with spinal tumor in our hospital were detected by MRI before surgery,and the accuracy of the two groups were compared and analyzed.ResultsFor 60 patients diagnosed of hemangioblastoma 1 case,a type cel tumor of 14 cases,neuroblastoma 3 cases,metastasis 11 cases, meningioma 11 cases,the ependymal membrane tumor 8 cases,spirit fibroma 6 cases,lipoma 6 cases. During the operation for pathological examination was in the same.Conclusion Magnetic resonance imaging for the diagnosis of spinal tumors has a good effect,and easy to operate,and the patient's injury is smal.

  19. 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.

  20. Hanford Nuclear Energy Center: a conceptual study

    Energy Technology Data Exchange (ETDEWEB)

    Harty, H. (comp.)

    1978-09-30

    The objective of the study is to develop an improved understanding of the nuclear energy center (NEC) concept and to identify research and development needed to evaluate the concept fully. A specific context was selected for the study--the Hanford site. Thus, the study primarily addresses the HNEC concept, but the findings are extrapolated to generic NECs where possible. The major emphasis in the HNEC study was to explore potential technical and environmental problems in a specific context and in sufficient detail to evaluate potential problems and propose practical solutions. The areas of concern are typical of those considered in preparing environmental and safety analysis reports, including: topics dealing with engineering choices (e.g., site selection, heat sink management, electrical transmission, and reliability of generation); environmental matters (e.g., terrestrial and radiological effects); socioeconomic factors (e.g., community impacts); and licensing considerations.

  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. 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.

  3. 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.

  4. 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...

  5. 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.

  6. New Progresses in Study of Bifid Mandibular Canal%下颌双神经管的研究进展

    Institute of Scientific and Technical Information of China (English)

    杨晓莉; 邹德荣

    2015-01-01

    锥形束CT(cone-beam computed tomography,CBCT)应用于口腔部位的三维成像,是近年来口腔医生关注的热点,常被应用于口腔种植学.下颌后区是种植的重要部位,同时也是双神经管变异的常发地带.本文综述了下颌双神经管的分类,运用CBCT研究的新进展,对其存在的临床意义进行总结.%Cone-beam CT(cone-beam computed tomography, CBCT) applied to the oral part of three-dimensional imag-ing, is the focus of attention in recent years and used in dental implantology frequently. Mandibular posterior region is an important part of implanting, but also a risk place about anatomic variation of the mandible. The classification of bi-fid mandibular canal, the use of new progress CBCT study, the clinical significance of their presence, summarized were in this passage.

  7. Microbiological evaluation of different irrigation protocols on root canal disinfection in teeth with apical periodontitis: an in vivo study.

    Science.gov (United States)

    Cohenca, Nestor; Silva, Lea Assed Bezerra; Silva, Raquel Assed Bezerra; Nelson-Filho, Paulo; Heilborn, Carlos; Watanabe, Evandro; Saraiva, Maria Conceição Pereira

    2013-01-01

    The present in vivo study was designed to evaluate the efficacy of apical negative pressure irrigation (ANP), passive ultrasonic irrigation (PUI) and positive pressure irrigation (PP) in the reduction of intracanal bacteria of dogs' teeth with pulp necrosis and apical periodontitis. Eighty root canals were randomly distributed into 3 experimental and 2 control groups according to the irrigation delivery system: group ANP (n=20), group PUI (n=20), group PP (n=20), group PC (positive control - sterile saline irrigation; n=10) and group NC (negative control - vital pulps not subjected to bacterial inoculation; n=10). The first sample (S1) was collected at baseline, and the second sample (S2) was collected after the disinfection protocols. All samples were seeded in culture media for anaerobic bacteria. CFU counts were analyzed statistically by the Kruskal-Wallis, Dwass-Steel-Critchlow-Fligner post-hoc and Chi-square followed by Tukey like multiple comparisons for proportions (α=0.05). All experimental groups were effective in reducing Gram-positive bacteria compared with PC (p0.05). In dog's teeth with apical periodontitis, the use of ANP and PUI can be considered promising disinfection protocols as both delivery systems promoted a significant bacterial reduction.

  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. An electron microscopic study of the development of the ependyma of the central canal of the mouse spinal cord.

    OpenAIRE

    Sturrock, R R

    1981-01-01

    The central canal of the adult mouse spinal cord is lined for most of its extent by ependymal cells which are rich in microfilaments and whose apical surface is covered with matted, broad microvilli. The canal itself is filled with amorphous material containing glycogen granules. Two forms of this material are present, a dark form rich in glycogen, and a light form containing a few glycogen granules. Each type appears to be surrounded by a membrane. The upper cervical region, however, has a l...

  10. 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.

  11. 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

  12. 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

  13. 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

  14. The Effect of EDTA and Citric Acid on Smear Layer Removal of Mesial Canals of First Mandibular Molars, A Scanning Electron Microscopic Study

    Directory of Open Access Journals (Sweden)

    A Khademi

    2004-04-01

    Full Text Available Background: The purpose of this in vitro study was to determine the effect of EDTA and citric acid on smear layer removal in different regions of root canals. Methods: In this study, mesial roots of 48 freshly extracted human mature mandibular first molar teeth with curved mesial roots of about 15-45 degrees and lengths of 20-23 mm were used. Instrumentation was done using the crown down technique by hand and rotary filing. Irrigant used during instrumentation was NaOCl. The teeth were divided in three groups. The mesial canals of teeth were irrigated by 17% EDTA in group I, 7% citric acid in group II and 5.25% NaOCl in group III as the control group. Then, the mesial roots were split in to two parts and studied under scanning electron microscopy. Results: The degree of cleanliness by 17% EDTA and 7% citric acid were 96.55% and 95% respectively. Although both solutions seem to be appropriate, their difference was statistically significant (P<0.05 and EDTA proved better than citric acid especially in middle and apical thirds of canals. The smear layer removal in apical area was less than that in other areas and was maximum in the middle third. However, the removal of smear layer in apical area was acceptable in both groups. Conclusion: It seems that use of both 17% EDTA and 7% citric acid offer desired results and they can remove smear layer from narrow and curved canals especially from apical region. Keywords: EDTA, citric acid, smear layer, irrigation

  15. 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.

  16. 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)

  17. Antimicrobial efficacy of different root canal sealers by using real-time polymerase chain reaction: An ex vivo study

    Directory of Open Access Journals (Sweden)

    R Gnana Seelan

    2015-01-01

    Full Text Available Background: Root canal sealers help to minimize leakage, provides antimicrobial activity to reduce the possibility of residual bacteria, and to resolve periapical lesion. Aim: To compare five different root canal sealers against Enterococcus faecalis in an infected root canal model by using real-time polymerase chain reaction (RT-PCR. Settings and Design: Sixty human mandibular premolars were sectioned to standardize a uniform length of 14 mm. Fifty microliters of the inoculum containing E. faecalis were transferred into each microcentrifuge tube (n = 60. The samples were divided into six groups Tubli-Seal, Apexit Plus, Fillapex, AH Plus, RoekoSeal, and Positive control, respectively. Materials and Methods: Five groups after the incubation with the microorganism E. faecalis were coated with different root canal sealers and obturated using F3 ProTaper Gutta-percha point. The dentinal shavings were collected and analyzed for RT-PCR. Statistical Analysis: The mean difference between six groups was calculated using analysis of variance and post-hoc test. Results: The highest antibacterial activity was achieved with Tubli-Seal (1938.13 DNA in pictogram [pg] and least by RoekoSeal (3034.54 DNA in pg. Conclusion: The maximum antimicrobial activity was achieved AH Plus and Tubli-Seal. RT-PCR can be used as a valuable and accurate tool for testing antimicrobial activity.

  18. 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.

  19. 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.

  20. Sonic versus ultrasonic activation for removal of calcium hydroxide from curved root canals: an in vitro study.

    Directory of Open Access Journals (Sweden)

    Tamara Cid

    2014-12-01

    Full Text Available To compare the remaining calcium hydroxide (Ca(OH2 coated area in the apical third of curved canals after sonic and ultrasonic activation using Scanning Electron Microscope (SEM. Permanent mandibular molars were collected. Those which radiographically presented a curvature between 15º and 30° in the mesial root were included. A total of 39 mesiolinguales canals were instrumented with rotary ProTaper and filled with Ca(OH2 mixed with propylene glycol. They were randomly divided into three groups according to the type of removal. Group I: three inserts with File F2 and 2ml of 5.25% sodium hypochlorite (NaOCl irrigation between each insertion. Group II: three sonic activations, irrigattion with 2ml of 5.25% NaOCl between activations. Group III: three ultrasonic activations irrigating with 2ml of 5.25% NaOCl between activations. Three root canals were left without filling and other three were completely filled as positive and negative control, respectively. Then, they were fractured lengthwise to get two sections. The apical third of the root canal of each section was taken x-rays with SEM and subsequently, in an area of 100.000um2, the remaining Ca(OH2 coated surface from both sections was measured using ImageJ 1.47. They were analyzed with one-way ANOVA using Graph Pad-Prism (5.01. The percentage of the remaining Ca(OH2 coated area in group I was 62.93%, 51.77% in group II, and 58.90% in group III. There were no significant differences between the three groups (p>0.01. There are no significant differences in the percentage of the remaining Ca(OH2 coated area in the apical third of curved root canals when comparing sonic and ultrasonic activation using SEM.

  1. [Upper premolars: study of the number of roots and their canals].

    Science.gov (United States)

    Sánchez Mercant, H; Mangarelli Vence, A A

    1989-08-01

    The number of roots and cannals were observed and studied in upper bicuspids. For the study of the root cannals was used a diafanization technique. The results were prosessed by stadistic analysis and compared with those published. By the observation, in this work, was stated that the first upper bicuspid has one root and two cannals in the most of the cases. This situation was confirmed by stadistic analysis. Conclusions were extracted refering them to the clinical application.

  2. Nuclear Structure and Nuclear Astrophysics Studies with Fast Heavy-Ion Beams

    Science.gov (United States)

    Motobayashi, Tohru

    Collaboration between France and Japan on studies with fast RI (radioactive isotope) beams and related technical developments started in 1980s, when the GANIL accelerators and RIKEN cyclotron complex started operation and RI beam production technique was developed. Several examples of collaboration on nuclear physics and nuclear astrophysics experiments including related technical development are discussed.

  3. 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.

  4. 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.

  5. Efficacy of Twisted File Adaptive, Reciproc and ProTaper Universal Retreatment instruments for root-canal-filling removal: A cone-beam computed tomography study.

    Science.gov (United States)

    Akbulut, Makbule Bilge; Akman, Melek; Terlemez, Arslan; Magat, Guldane; Sener, Sevgi; Shetty, Heeresh

    2016-01-01

    The aim of this study was to evaluate the efficacy of Twisted File (TF) Adaptive, Reciproc, and ProTaper Universal Retreatment (UR) System instruments for removing root-canal-filling. Sixty single rooted teeth were decoronated, instrumented and obturated. Preoperative CBCT scans were taken and the teeth were retreated with TF Adaptive, Reciproc, ProTaper UR, or hand files (n=15). Then, the teeth were rescanned, and the percentage volume of the residual root-canal-filling material was established. The total time for retreatment was recorded, and the data was statistically analyzed. The statistical ranking of the residual filling material volume was as follows: hand file=TF Adaptive>ProTaper UR=Reciproc. The ProTaper UR and Reciproc systems required shorter periods of time for retreatment. Root canal filling was more efficiently removed by using Reciproc and ProTaper UR instruments than TF Adaptive instruments and hand files. The TF Adaptive system was advantageous over hand files with regard to operating time.

  6. Book Review of Emerging Markets for Ecosystem Services: A Case Study of the Panama Canal Watershed

    Science.gov (United States)

    This book is an outstanding contribution to our current, applied knowledge on markets of ecosystems services. In an integrated framework of study, the authors assessed the opportunities and limitations of carbon sequestration mainly via reforestation, hydrological services (water quantity and qualit...

  7. 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.

  8. ROLE OF MODIFIED EPLEY’S MANEUVER AND BRANDT-DAROFF EXERCISES IN TREATMENT OF POSTERIOR CANAL BPPV: A COMPARATIVE STUDY

    Directory of Open Access Journals (Sweden)

    Devangi S. Desai

    2015-06-01

    Full Text Available Background: Benign paroxysmal positional vertigo (BPPV defined by Dix and Hallpike is one of the most common disorders causing vertigo. BPPV is more prevalent in adults and in women. BPPV mostly develops in the posterior semicircular canal. The main symptom of BPPV is vertigo induced by a change in head position with respect to gravity. The Dix-Hallpike test is the most commonly used test to confirm the diagnosis of posterior canal BPPV. Treatment options for posterior canal BPPV are Epley's maneuver, Liberatory maneuver and Brandt-Daroff exercises. In modified epley’s maneuver few modifications were done in original epley’s maneuver without affecting outcome. Objective: To assess effectiveness of modified epley’s maneuver as well as combination of modified epley’s maneuver with Brandt-Daroff exercise in patients with posterior canal BPPV and to compare both treatment protocols. Methodology: All patients were examined by Dix-Hallpike test (D-H Test and those suffering from posterior canal BPPV and fulfilling inclusion criteria were taken up for the study. Total thirty five patients took part in this study on a voluntary basis after signing consent form. The patients were randomly assigned to two groups. In group 1, combination of modified epley’s maneuver and Brandt-Daroff exercise were given and in group 2 only modified epley’s maneuver was given. All patients were reexamined after 1 week of treatment and were asked to come for follow up after 1 month. In follow up visits response to Dix – Hallpike maneuver and Dizziness Handicap Inventory(DHI were assessed as outcome measures. Result: Data collected through this study showed highly significant improvement in DHI score and response to D-H test when intragroup comparison is made in both the groups after 1 week and 1 month of treatment at 1% level of significance. When intergroup comparison is made we found better improvement in group 2 after 1 week and in group 1 after 1 month of

  9. NUCLEAR MAGNETIC RESONANCE STUDIES OF URANOCENES

    Energy Technology Data Exchange (ETDEWEB)

    Luke, Wayne D.; Streitwieser, Jr., Andrew

    1979-12-01

    In the past several years a substantial amount of work has been devoted toward evaluation of the contact and pseudocontact contributions to the observed isotropic shifts in H nuclear magnetic resonance (NMR) spectra of uranium(IV) organometallic compounds. One reason for interest in this area arises from using the presence of contact shifts as a prcbe for covalent character in the uranium carbon bonds in these compounds. Several extensive {sup 1}H NNR studies on Cp{sub 3} U-X compounds and less extensive studies on uranocenes have been reported. Interpretation of these results suggests that contact shifts-contribute significantly to the observed isotropic shifts. Their presence has been taken as indicative of covalent character of metal carbon bonds in these systems, but agreement is not complete. In this paper we shall review critically the work reported on uranocenes in the light of recent results and report recent work on attempted separation of the observed isotropic shifts in alkyluranocenes into contact and pseudocontact components.

  10. 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.)

  11. 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.

  12. 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.

  13. Questioning nuclear waste substitution: a case study.

    Science.gov (United States)

    Marshall, Alan

    2007-03-01

    This article looks at the ethical quandaries, and their social and political context, which emerge as a result of international nuclear waste substitution. In particular it addresses the dilemmas inherent within the proposed return of nuclear waste owned by Japanese nuclear companies and currently stored in the United Kingdom. The UK company responsible for this waste, British Nuclear Fuels Limited (BNFL), wish to substitute this high volume intermediate-level Japanese-owned radioactive waste for a much lower volume of much more highly radioactive waste. Special focus is given to ethical problems that they, and the UK government, have not wished to address as they move forward with waste substitution. The conclusion is that waste substitution can only be considered an ethical practice if a set of moderating conditions are observed by all parties. These conditions are listed and, as of yet, they are not being observed.

  14. 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.

  15. 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.

  16. 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.)

  17. Ependyma of the central canal of the rat spinal cord: a light and transmission electron microscopic study.

    OpenAIRE

    Bruni, J.E.; Reddy, K

    1987-01-01

    Ependymal cells of the rat central canal were examined with a view to identifying features that distinguish them regionally and from their counterparts elsewhere in the ventricular system. The results revealed that the lining consisted for the most part of a pseudostratified layer of uniformly organised cuboidal to columnar ependymal cells present in largest numbers in lumbar and sacral segments and in the conus. Two cell variants were identified on the basis of the presence or absence of a r...

  18. Transportation capabilities study of DOE-owned spent nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Clark, G.L.; Johnson, R.A.; Smith, R.W. [Packaging Technology, Inc., Tacoma, WA (United States); Abbott, D.G.; Tyacke, M.J. [Lockheed Idaho Technologies Co., Idaho Falls, ID (United States)

    1994-10-01

    This study evaluates current capabilities for transporting spent nuclear fuel owned by the US Department of Energy. Currently licensed irradiated fuel shipping packages that have the potential for shipping the spent nuclear fuel are identified and then matched against the various spent nuclear fuel types. Also included are the results of a limited investigation into other certified packages and new packages currently under development. This study is intended to support top-level planning for the disposition of the Department of Energy`s spent nuclear fuel inventory.

  19. Nuclear Quadrupole Resonance Study of Potassium - - Chloride.

    Science.gov (United States)

    Ramia, Maximo Elias

    Fast Fourier transform nuclear quadrupole resonance (NQR) was used to study the cubic antifluorite crystal potassium hexacloro-osmate, K(,2)OsCl(,6). The study of the ('35)Cl and ('37)Cl resonances were performed on three samples of K(,2)OsCl(,6), a powder sample, a powder sample recrystallized from D(,2)O and a single crystal sample. The studies were carried out in the temperature range 300 to 6K. A detailed study of the ('35)Cl and ('37)Cl NQR lineshapes, in the temperature range 70 to 300K, showed that the lineshapes reflect the strain fields produced by lattice dislocations and point defects. The temperature evolution of these strain fields give rise to a satellite line which previously was attributed to H('+) ion impurities present in the samples. A comprehensive study of the temperature evolution of the NQR spectrum in the vicinity of the phase transition revealed a drop of line intensity and the progressive appearance of an extra broad resonance component. Both effects are associated with the existence of precursor dynamic clusters at temperatures higher than T(,C). Qualitatively similar but quantitatively different behaviour was observed in the powder and single crystal samples. Although the precursor clusters are an intrinsic property of the phrase transition, their detailed dynamics is sample independent. A NQR study of the tetragonal phase showed that at the lowest temperature the ratio of line intensities is 2:1. The phase shift effect previously observed in the tetragonal phase of K(,2)ReCl(,6) was also observed in K(,2)OsCl(,6). The effect has been explained as an experimental artifact introduced by the truncation of the FID due to the spectrometer dead time. Spin-lattice relaxation measurements in the cubic phase show two component relaxation in the vicinity of T(,C). The behaviour is quantitatively different in the powder and single crystal samples. The short relaxation time is associated with dynamic clusters. Spin-lattice relaxation time

  20. Studying Nuclear Level Densities of 238U in the Nuclear Reactions within the Macroscopic Nuclear Models

    Science.gov (United States)

    Razavi, Rohallah; Rahmatinejad, Azam; Kakavand, Tayeb; Taheri, Fariba; Aghajani, Maghsood; Khooy, Asghar

    2016-02-01

    In this work the nuclear level density parameters of 238U have been extracted in the back-shifted Fermi gas model (BSFGM), as well as the constant temperature model (CTM), through fitting with the recent experimental data on nuclear level densities measured by the Oslo group. The excitation functions for 238U(p,2nα)233Pa, and 238U(p,4n)235Np reactions and the fragment yields for the fragments of the 238U(p,f) reaction have been calculated using obtained level density parameters. The results are compared to their corresponding experimental values. It was found that the extracted excitation functions and the fragment yields in the CTM coincide well with the experimental values in the low-energy region. This finding is according to the claim made by the Oslo group that the extracted level densities of 238U show a constant temperature behaviour.

  1. 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

  2. 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.

  3. Nuclear Magnetic Resonance Technology for Medical Studies.

    Science.gov (United States)

    Budinger, Thomas F.; Lauterbur, Paul C.

    1984-01-01

    Reports on the status of nuclear magnetic resonance (NMR) from theoretical and clinical perspectives, reviewing NMR theory and relaxation parameters relevant to NMR imaging. Also reviews literature related to modern imaging strategies, signal-to-noise ratio, contrast agents, in vivo spectroscopy, spectroscopic imaging, clinical applications, and…

  4. 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.

  5. Studies of Fourteen Nuclear-Powered Airplanes

    Energy Technology Data Exchange (ETDEWEB)

    Hutton, J. N.; McCulloch, J. C.; Schmill, W. C.; Ward, W. H.

    1952-09-01

    A representative series of aircraft which could be powered by a relatively low-temperature liquid-coolant-cycle nuclear power plant are described. Present aircraft such as the B-36, B-52, and B-47 bombers as well as new designs were investigated. Design and performance characteristics of all the aircraft are presented.

  6. 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

  7. 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

  8. 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.

  9. Canals, Bypass 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 'Bypass Canal'. Data by this publisher are often provided in...

  10. Recent advances in maize nuclear proteomic studies reveal histone modifications.

    Science.gov (United States)

    Casati, Paula

    2012-01-01

    The nucleus of eukaryotic organisms is highly dynamic and complex, containing different types of macromolecules including DNA, RNA, and a wide range of proteins. Novel proteomic applications have led to a better overall determination of nucleus protein content. Although nuclear plant proteomics is only at the initial phase, several studies have been reported and are summarized in this review using different plants species, such as Arabidopsis thaliana, rice, cowpea, onion, garden cress, and barrel clover. These include the description of the total nuclear or phospho-proteome (i.e., Arabidopsis, cowpea, onion), or the analysis of the differential nuclear proteome under different growth environments (i.e., Arabidopsis, rice, cowpea, onion, garden cress, and barrel clover). However, only few reports exist on the analysis of the maize nuclear proteome or its changes under various conditions. This review will present recent data on the study of the nuclear maize proteome, including the analysis of changes in posttranslational modifications in histone proteins.

  11. Studies of Fluctuation Processes in Nuclear Collisions

    Energy Technology Data Exchange (ETDEWEB)

    Ayik, Sakir [Tennessee Technological Univ., Cookeville, TN (United States). Dept. of Physics

    2016-04-14

    The standard one-body transport approaches have been extensively applied to investigate heavy-ion collision dynamics at low and intermediate energies. At low energies the approach is the mean-field description of the time-dependent Hartree-Fock (TDHF) theory. At intermediate energies the approach is extended by including a collision term, and its application has been carried out mostly in the semi-classical framework of the Boltzmann-Uhling-Uhlenbeck (BUU) model. The standard transport models provide a good understanding of the average properties of the collision dynamics in terms of the effective interactions in both low and intermediate energies. However, the standard models are inadequate for describing the fluctuation dynamics of collective motion at low energies and disassembling of the nuclear system into fragments at intermediate energies resulting from the growth of density fluctuations in the spinodal region. Our tasks have been to improve the standard transport approaches by incorporating fluctuation mechanisms into the description. There are mainly two different mechanisms for fluctuations: (i) Collisional fluctuations generated by binary nucleon collisions, which provide the dominant mechanism at intermediate energies, and (ii) One-body mechanism or mean-field fluctuations, which is the dominant mechanism at low energies. In the first part of our project, the PI extended the standard transport model at intermediate energies by incorporating collisional mechanism according to the “Generalized Langevin Description” of Mori formalism. The PI and his collaborators carried out a number of applications for describing dynamical mechanism of nuclear multi fragmentations, and nuclear collective response in the semi-classical framework of the approach, which is known as the Boltzmann-Langevin model. In the second part of the project, we considered dynamical description at low energies. Because of the effective Pauli blocking, the collisional dissipation and

  12. Study of nuclear level densities for exotic nuclei

    Directory of Open Access Journals (Sweden)

    M Nasri Nasrabadi

    2012-06-01

    Full Text Available Nuclear level density (NLD is one of the properties of nuclei with widespread applications in astrophysics and nuclear medicine. Since there has been little experimental and theoretical research on the study of nuclei which are far from stability line, studying NLD for these nuclei is of crucial importance. Also, as NLD is an important input for nuclear research codes, hence studying the methods for calculation of this parameter is essential. Besides introducing various methods and models for calculating NLD for practical applications, we used exact spectra distribution (SPDM for determining NLD of two neutron and proton enriched exotic nuclei with the same mass number.

  13. 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.

  14. Progresses in studies of nuclear actin

    Institute of Scientific and Technical Information of China (English)

    ZHU Xiaojuan; ZENG Xianlu; SONG Zhaoxia; HAO Shui

    2004-01-01

    Actin is a protein abundant in cells. Recently, it has been proved to be universally existent in the nuclei of many cell types. Actin and actin-binding proteins, as well as actin-related proteins, are necessary for the mediation of the conformation and function of nuclear actin, including the transformation of actin between unpolymerized and polymerized, chroinatin remodeling, regulation of gene expression and RNA processing as well as RNA transportation. In this paper, we summarized the progresses in the research of nu clear actin.

  15. A panel study of nuclear energy consumption and economic growth

    Energy Technology Data Exchange (ETDEWEB)

    Apergis, Nicholas [Department of Banking and Financial Management, University of Piraeus, Karaoli and Dimitriou 80, Piraeus, ATTIKI 18534 (Greece); Payne, James E. [Interim Dean and Professor of Economics, College of Arts and Sciences, Illinois State University, Normal, IL 61790-4100 (United States)

    2010-05-15

    This study examines the relationship between nuclear energy consumption and economic growth for sixteen countries within a multivariate panel framework over the period 1980-2005. Pedroni's (1999, 2004) heterogeneous panel cointegration test reveals there is a long-run equilibrium relationship between real GDP, nuclear energy consumption, real gross fixed capital formation, and the labor force with the respective coefficients positive and statistically significant. The results of the panel vector error correction model finds bidirectional causality between nuclear energy consumption and economic growth in the short-run while unidirectional causality from nuclear energy consumption to economic growth in the long-run. Thus, the results provide support for the feedback hypothesis associated with the relationship between nuclear energy consumption and economic growth. (author)

  16. 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

  17. Three root canals in the maxillary second premolar

    Directory of Open Access Journals (Sweden)

    de Almeida-Gomes Fabio

    2009-01-01

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

  18. Global study of nuclear modifications on parton distribution functions

    CERN Document Server

    Wang, Rong; Fu, Qiang

    2016-01-01

    A global analysis of nuclear medium modifications of parton distributions is presented using deeply inelastic scattering data of various nuclear targets. Two obtained data sets are provided for quark and gluon nuclear modification factors, referred as nIMParton16. One is from the global fit only to the experimental data of isospin-scalar nuclei (Set A), and the other is from the fit to all the measured nuclear data (Set B). The scale-dependence is described by DGLAP equations with nonlinear corrections in this work. The Fermi motion and off-shell effect, nucleon swelling, and parton-parton recombination are taken into account together for modeling the complicated $x$-dependence of nuclear modification. The nuclear gluon shadowing in this paper is dynamically generated by the QCD evolution of parton splitting and recombination processes with zero gluon density at the input scale. Sophisticated nuclear dependence of nuclear medium effects is studied with only two free parameters. With the obtained free paramete...

  19. Defining the Location of the Adductor Canal Using Ultrasound

    DEFF Research Database (Denmark)

    Wong, Wan Yi; Bjørn, Siska; Strid, Jennie Maria Christin;

    2016-01-01

    BACKGROUND AND OBJECTIVES: The precise location of the adductor canal remains controversial among anesthesiologists. In numerous studies of the analgesic effect of the so-called adductor canal block for total knee arthroplasty, the needle insertion point has been the midpoint of the thigh......, determined as the midpoint between the anterior superior iliac spine and base of patella. "Adductor canal block" may be a misnomer for an approach that is actually an injection into the femoral triangle, a "femoral triangle block." This block probably has a different analgesic effect compared...... with an injection into the adductor canal. We sought to determine the exact location of the adductor canal using ultrasound and relate it to the midpoint of the thigh. METHODS: Twenty-two volunteers were examined using ultrasound. The proximal end of the adductor canal was identified where the medial border...

  20. 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.

  1. Research Progress of Nuclear Astrophysics Physics:Study of Key Scientific Problems in Nuclear Synthesis

    Institute of Scientific and Technical Information of China (English)

    GUO; Bing; LIU; Wei-ping; LI; Zhi-hong; WANG; You-bao; HE; Jian-jun; SHI; Jian-rong; TANG; Xiao-dong; YAN; Sheng-quan; SU; Jun; LI; Yun-ju; ZENG; Sheng; LIAN; Gang; BAI; Xi-xiang; CHEN; Yong-shou; PANG; Dan-yang; GU; Jian-zhong; HAN; Zhi-yu; LI; Xin-yue

    2015-01-01

    1 Summary A systematic study of the key scientific problems in nuclear synthesis has been conducted.Significant research achievements from several important subjects such as direct measurement of astrophysical reaction,observation of abundances of elements,studies on decay properties of nuclei and reaction rates of primordial nucleosynthesis have been made utilizing large scientific facilities from China

  2. Basic research for nuclear energy. y Study on the nuclear materials technology

    Energy Technology Data Exchange (ETDEWEB)

    Kuk, I. H.; Lee, H. S.; Jeong, Y. H.; Sung, K. W.; Han, J. H.; Lee, J. T.; Lee, H. K.; Kim, S. J.; Kang, H. S.; An, D. H.; Kim, K. R.; Park, S. D.; Han, C. H.; Jung, M. K.; Oh, Y. J.; Kim, K. H.; Kim, S. H.; Back, J. H.; Kim, C. H.; Lim, K. S.; Kim, Y. Y.; Na, J. W.; Ku, J. H.; Lee, D. H.

    1996-12-01

    A study on the nuclear materials technologies which are necessary to establish the base for alloy development was performed. - The feasibility study on the application of Zircaloy scrap waste for hydrogen storage - The development of metal hydride battery for energy storage system - The establishment of transmission electron microscopy database for nuclear materials - The basic technology for the development of cladding materials for high burnup - The water chemistry technology for secondary system pH control and the photocatalysis technology for decomposition and removal of organics. - Improvement of primary component integrity of PWR by Zinc injection. (author). 175 refs., 58 tabs., 262 figs.

  3. 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.

  4. Effect of diode laser and ultrasonics with and without ethylenediaminetetraacetic acid on smear layer removal from the root canals: A scanning electron microscope study

    Science.gov (United States)

    Amin, Khalid; Masoodi, Ajaz; Nabi, Shahnaz; Ahmad, Parvaiz; Farooq, Riyaz; Purra, Aamir Rashid; Ahangar, Fayaz Ahmad

    2016-01-01

    Aim: To evaluate the effect of diode laser and ultrasonics with and without ethylenediaminetetraacetic acid (EDTA) on the smear layer removal from root canals. Materials and Methods: A total of 120 mandibular premolars were decoronated to working the length of 12 mm and prepared with protaper rotary files up to size F3. Group A canals irrigated with 1 ml of 3% sodium hypochlorite (NaOCl) followed by 3 ml of 3% NaOCl. Group B canals irrigated with 1 ml of 17% EDTA followed by 3 ml of 3% NaOCl. Group C canals lased with a diode laser. Group D canals were initially irrigated with 0.8 ml of 17% EDTA the remaining 0.2 ml was used to fill the root canals, and diode laser application was done. Group E canals were irrigated with 1 ml distilled water with passive ultrasonic activation, followed by 3 ml of 3% NaOCl. Group F canals were irrigated with 1 ml EDTA with passive ultrasonic activation, followed by 3 ml of 3% NaOCl. Scanning electron microscope examination of canals was done for remaining smear layer at coronal middle and apical third levels. Results: Ultrasonics with EDTA had the least smear layer scores. Conclusion: Diode laser alone performed significantly better than ultrasonics. PMID:27656060

  5. Neutron Diffraction Studies of Nuclear Magnetic Ordering in Copper

    DEFF Research Database (Denmark)

    Jyrkkiö, T.A.; Huiku, M.T.; Siemensmeyer, K.;

    1989-01-01

    to depend strongly on the external magnetic field between zero and the critical fieldB c=0.25 mT, indicating the existence of at least two antiferromagnetic phases. The results are compared to previous measurements of the magnetic susceptibility. Theoretical calculations do not provide a full explanation......We have constructed a two-stage nuclear demagnetization cryostat for neutron diffraction studies of nuclear magnetism in copper. The cryostat is combined with a two-axis neutron spectrometer which can use both polarized and unpolarized neutrons. By demagnetizing highly polarized copper nuclear...

  6. Nuclear electric propulsion mission engineering study. Volume 2: Final report

    Science.gov (United States)

    1973-01-01

    Results of a mission engineering analysis of nuclear-thermionic electric propulsion spacecraft for unmanned interplanetary and geocentric missions are summarized. Critical technologies associated with the development of nuclear electric propulsion (NEP) are assessed, along with the impact of its availability on future space programs. Outer planet and comet rendezvous mission analysis, NEP stage design for geocentric and interplanetary missions, NEP system development cost and unit costs, and technology requirements for NEP stage development are studied.

  7. Evaluation of torque within manual preparation with root canal instruments

    OpenAIRE

    Gorski, Christof

    2016-01-01

    Used root canal instruments are often deformed; they can fracture, persist and reinfect teeth. There are no evident studies consulting torque and manual preparation of root canals. Thus, the purpose of this study is the evaluation of torque within manual preparation in connection with its impact on file deformation. With the aid of torque measurement a change in dental education could potentially be achieved.

  8. Spent Nuclear Fuel Vibration Integrity Study

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jy-An John [ORNL; Wang, Hong [ORNL; Jiang, Hao [ORNL; Yan, Yong [ORNL; Bevard, Bruce Balkcom [ORNL

    2016-01-01

    The objective of this research is to collect dynamic experimental data on spent nuclear fuel (SNF) under simulated transportation environments using the Cyclic Integrated Reversible-Bending Fatigue Tester (CIRFT), the hot-cell testing technology developed at Oak Ridge National Laboratory (ORNL). The collected CIRFT data will be utilized to support ongoing spent fuel modeling activities, and support SNF transportation related licensing issues. Recent testing to understand the effects of hydride reorientation on SNF vibration integrity is also being evaluated. CIRFT results have provided insight into the fuel/clad system response to transportation related loads. The major findings of CIRFT on the HBU SNF are as follows: SNF system interface bonding plays an important role in SNF vibration performance, Fuel structure contributes to the SNF system stiffness, There are significant variations in stress and curvature of SNF systems during vibration cycles resulting from segment pellets and clad interaction, and SNF failure initiates at the pellet-pellet interface region and appears to be spontaneous. Because of the non-homogeneous composite structure of the SNF system, finite element analyses (FEA) are needed to translate the global moment-curvature measurement into local stress-strain profiles. The detailed mechanisms of the pellet-pellet and pellet-clad interactions and the stress concentration effects at the pellet-pellet interface cannot be readily obtained directly from a CIRFT system measurement. Therefore, detailed FEA is used to understand the global test response, and that data will also be presented.

  9. 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.

  10. The Kra Canal and Southeast Asian Relations

    Directory of Open Access Journals (Sweden)

    Rini Suryati Sulong

    2012-01-01

    Full Text Available This paper is a conceptual study that attempts to analyse the possible effects of the development of the Kra Isthmus Canal on ASEAN relations. The Kra Canal would constitute a mega-project, a passageway that would connect the Andaman Sea and the Gulf of Thailand at the Isthmus of Kra, Thailand. Although the proposed Kra Canal is projected to provide many economic and trade benefits to Thailand, and to the region as a whole, steps toward its development have yet to be taken. There has been much debate over the costs for trade, the costs for the environment, national and regional security concerns, as well as major concerns related to political and economic relations in the region. Therefore, one of the main purposes of this study is to contribute to the debate on the possible impact of the devel-opment of the Kra Canal on ASEAN’s regional relations. In particular, it proposes that the development of the Kra Canal could threaten regional solidarity as it would physically divide maritime Southeast Asia from main-land Southeast Asia, which would ultimately result in an economic, cultural and political divide of ASEAN itself.

  11. Studies of Health Effects from Nuclear Testing near the Semipalatinsk Nuclear Test Site, Kazakhstan

    Directory of Open Access Journals (Sweden)

    Bernd Grosche

    2015-05-01

    Full Text Available The nuclear bomb testing conducted at the Semipalatinsk nuclear test site in Kazakhstan is of great importance for today’s radiation protection research, particularly in the area of low dose exposures. This type of radiation is of particular interest due to the lack of research in this field and how it impacts population health. In order to understand the possible health effects of nuclear bomb testing, it is important to determine what studies have been conducted on the effects of low dose exposure and dosimetry, and evaluate new epidemiologic data and biological material collected from populations living in proximity to the test site. With time, new epidemiological data has been made available, and it is possible that these data may be linked to biological samples. Next to linking existing and newly available data to examine health effects, the existing dosimetry system needs to be expanded and further developed to include residential areas, which have not yet been taken into account. The aim of this paper is to provide an overview of previous studies evaluating the health effects of nuclear testing, including some information on dosimetry efforts, and pointing out directions for future epidemiologic studies.

  12. 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.

  13. The Effect of Canal Contamination with Saliva on Apical Sealing

    Directory of Open Access Journals (Sweden)

    S Sabaghi

    2014-08-01

    Full Text Available Introduction: Root canal obturation aims at sealing the root canal system to prevent re-contamination of canal and periapical space. Presence of moisture in canal before obturation may posit a negative effect on the quality of canal sealing. Therefore, this study was conducted to investigate the effect of canal contamination with saliva on apical microleakage. Methods: In this laboratory study, 58 human uni-root teeth were cleaned and shaped for obturation with gutta percha and sealer AH26. In the case group, specimens were contaminated with human saliva immediately before obturation, whereas the teeth in the control group were kept dry. All canals were filled by lateral condensation technique. Moreover, the teeth were placed in methylene blue dye for 3 days. Dye penetration was measured using a stereomicrosope. As a matter of fact, the study data were analyzed via utilizing t-test. Results: A significant difference was found between the two groups in regard with the apical leakage(P<0.001. The microleakage mean of dye in the dry group was 3/48mm, whereas it was 6/36mm in the saliva contaminated group. Conclusion: The study findings revealed that complete drying of canal can improve apical sealing.

  14. 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

  15. Review on studies for external cost of nuclear power generation

    Energy Technology Data Exchange (ETDEWEB)

    Park, Byung Heung [Korea National University of Transportation, Chungju (Korea, Republic of); Ko, Won Il [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-12-15

    External cost is cost imposed on a third party when producing or consuming a good or service. Since the 1990s, the external costs of nuclear powered electricity production have been studied. Costs are a very important factor in policy decision and the external cost is considered for cost comparison on electricity production. As for nuclear fuel cycle, a chosen technology will determine the external cost. However, there has been little research on this issue. For this study, methods for external cost on nuclear power production have been surveyed and analyzed to develop an approach for evaluating external cost on nuclear fuel cycles. Before the Fukushima accident, external cost research had focused on damage costs during normal operation of a fuel cycle. However, accident cost becomes a major concern after the accident. Various considerations for external cost including accident cost have been used to different studies, and different methods have been applied corresponding to the considerations. In this study, the results of the evaluation were compared and analyzed to identify methodological applicability to the external cost estimation with nuclear fuel cycles.

  16. Nuclear transfer to study the nuclear reprogramming of human stem cells.

    Science.gov (United States)

    Saito, Shigeo; Sawai, Ken; Murayama, Yoshinobu; Fukuda, Keiichi; Yokoyama, Kazunari

    2008-01-01

    Research of stem cells will enable us to understand the development and function of tissues and organs in mammals. The ability to induce regeneration of new tissues from embryonic stem (ES) cells derived from cloned blastocysts via nuclear transfer can be expected in the not-too-distant future. The fact that there is no way except nuclear cloning for the return of differentiated cells to undifferentiated cells remains an interesting problem to be solved. We describe protocols for the production of cloned calves from bovine ES cells to study nuclear reprogramming ability of stem cells. The frequency of term pregnancies for blastocysts from ES cells is higher than those of early pregnancies and maintained pregnancies after nuclear transfer with bovine somatic cells. We also describe protocols for gene introduction into bovine ES cells in vitro, particularly the human leukocyte antigens (HLA). Bovine ES cells provide a powerful tool for the generation of transgenic clonal offspring. This technique, when perfected for humans, may be critical for neural stem cell transplantation.

  17. Synchronous rectal adenocarcinoma and anal canal adenocarcinoma

    Institute of Scientific and Technical Information of China (English)

    GU Jin; LI Jiyou; YAO Yunfeng; LU Aiping; WANG Hongyi

    2007-01-01

    It is difficult to distinguish a tectal carcinoma with anal metastases from coexistent synchronous anorectal carcinomas.The therapeutic strategy for rectal and anal carcinoma is so different that it should be clearly identified.Here,we report on the case of a 63-year-old man who presented with an upper-third rectal adenocarcinoma.Five months after resection,he developed an adenocarcinoma in the anal canal.The histological slides of both tumors were reviewed and immunohistochemical studies for cytokeratins(CKs)7 and 20 were performed.The index tumor demonstrated CK 7-/CK 20+and the second showed CK7+/CK20+.For this reason,we believe the present case had synchronous adenocarcinomas arising from anal canal and the rectum separately.It is very important to difierentiate the anorectal lesions pathologically because of the impact on the therapeutic options available,especially for the lesion arising in the anal canal.

  18. Benign paroxysmal positional vertigo simultaneously affecting several canals: a 46-patient series.

    Science.gov (United States)

    Soto-Varela, Andrés; Rossi-Izquierdo, Marcos; Santos-Pérez, Sofía

    2013-03-01

    Although it is uncommon for benign paroxysmal positional vertigo (BPPV) to affect more than one canal simultaneously, it is not exceptional. We attempt to determine whether these patients present differences relative to "single-canal" cases. A prospective study was done in patients with BPPV, divided into three groups: single-canal BPPV, multi-canal BPPV in one ear and multi-canal BPPV in both ears. Diagnosis was by Dix and Hallpike, supine roll and cephalic hyperextension tests. Treatment was according to the affected canals, by Semont, Epley, Lempert and Yacovino manoeuvres. Aetiology, sex, age, response to treatment, recurrence and final status in each of the three groups was evaluated. Five hundred and eighty-three patients were diagnosed with BPPV: 537 single-canal (92 %) and 46 multi-canal (8 %); of the latter, 36 bilateral and 10 unilateral cases. Basic differences between groups were: greater percentage of idiopathic cases in single-canal (p BPPV was more common in unilateral multi-canal (p = 0.006, Chi-square). No differences between groups in response to treatment, recurrence and final status were detected. There are aetiological differences between patients with single-canal BPPV, unilateral multi-canal BPPV and bilateral multi-canal BPPV. Response to therapeutic manoeuvres, however, shows that over 90 % of the patients in all the groups are cured.

  19. 上颌第一磨牙近中颊侧第二根管的锥形束CT影像学研究%Cone-beam CT imaging study of the second mesiobuccal root canal in maxillary first permanent molar

    Institute of Scientific and Technical Information of China (English)

    谢怡汀; 罗俊; 刘鹏; 林居红

    2012-01-01

    Objective To study the incidence of the second mesiobuccal root canal (MB2) in maxillary first permanent molar by cone-beam CT, and to provide imaging evidence for the clinical treatment of root canal. Methods The patients were grouped by age, 70 images were randomly chosen from each group, all of 420 cone-beam CT images. The cross-sectional images of the root canal in maxillary first permanent molar were intercepted. The mesiobuccal root canal number of maxillary first permanent molar and the position of the second mesiobuccal root canal were analyzed and studied. Results Cone-beam CT could clearly show the existence and distribution of the second mesiobuccal root canal in maxillary first permanent molar in the cross-sectional images of root canal. Conclusion Cone-beam CT can truly reflect the anatomical shape of the second mesiobuccal root canal in maxillary first permanent molar, and the image is clear, which provide an important and favorable reference for the clinical work.%目的 利用锥形束CT(CBCT)研究活体上颌第一磨牙近中颊侧第二根管(MB2)的发生率和根管影像,为临床根管治疗提供一定的影像学依据.方法 按年龄段分组,各随机选择70张,共420张锥形束CT扫描图像,截取上颌第一磨牙根管口横断面影像,针对上颌第一磨牙近中颊侧根管数目、近中颊侧第二根管根管口的位置进行分析研究.结果 锥形束CT能在根管口横断面上清晰显示上颌第一磨牙近中颊侧第二根管的存在和分布.结论 锥形束CT可以真实反映上颌第一磨牙近中颊侧第二根管的解剖形态,图像清晰,给临床工作提供了重要的、有利的参考.

  20. Study of stress in nuclear area workers: silent enemy

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Maria da Penha Sanches; Vanni, Silvia Regina [Centro Tecnologico da Marinha (CTMSP-SP), SP (Brazil); Andrade, Delvonei Alves de; Sabundjian, Gaiane, E-mail: delvonei@ipen.b, E-mail: gdjian@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    The nuclear accidents occurred in Three Mile Island, Chernobyl and Fukushima were influenced by human factors. The objective of this paper is to study about the factors that influence the level of stress of the nuclear area workers. The paper is based on theoretical assumptions on occupational stress and its manifestations. The methodology used is based on questionnaires and interviews, obtained from Martins' work published in 2008 about the study of human factors focused on research reactor operators IEA-R1, of the Instituto de Pesquisas Energeticas e Nucleares (IPEN). In that study were analyzed the accidents occurred by human failure. The results presented in this paper showed some improvements in the reactors operators' work, and health. Operational reliability and facilities safety also improved. (author)

  1. 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

  2. Spent nuclear fuel project design basis capacity study

    Energy Technology Data Exchange (ETDEWEB)

    Cleveland, K.J.

    1996-09-09

    A parametric study of the Spent Nuclear Fuel Project system capacity is presented. The study was completed using a commercially available software package to develop a summary level model of the major project systems. Alternative configurations, sub-system cycle times, and operating scenarios were tested to identify their impact on total project duration and equipment requirements.

  3. Analytical study of nozzle performance for nuclear thermal rockets

    Science.gov (United States)

    Davidian, Kenneth O.; Kacynski, Kenneth J.

    1991-01-01

    A parametric study has been conducted by the NASA-Lewis Rocket Engine Design Expert System for the convergent-divergent nozzle of the Nuclear Thermal Rocket system, which uses a nuclear reactor to heat hydrogen to high temperature and then expands it through the nozzle. It is established by the study that finite-rate chemical reactions lower performance levels from theoretical levels. Major parametric roles are played by chamber temperature and chamber pressure. A maximum performance of 930 sec is projected at 2700 K, and of 1030 at 3100 K.

  4. 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...

  5. Recent advances in maize nuclear proteomic studies reveal histone modifications

    Directory of Open Access Journals (Sweden)

    Paula eCasati

    2012-12-01

    Full Text Available The nucleus of eukaryotic organisms is highly dynamic and complex, containing different types of macromolecules including DNA, RNA, and a wide range of proteins. Novel proteomic applications have led to a better overall determination of nucleus protein content. Although nuclear plant proteomics is only at the initial phase, several studies have been reported and are summarized in this review using different plants species, such as Arabidopsis thaliana, rice, cowpea, onion, garden cress, and barrel clover. These include the description of the total nuclear or phospho-proteome (i.e. Arabidopsis, cowpea, onion, or the analysis of the differential nuclear proteome under different growth environments (i.e. Arabidopsis, rice, cowpea, onion, garden cress and barrel clover. However, only few reports exist on the analysis of the maize nuclear proteome or its changes under various conditions. This review will present recent data on the study of the nuclear maize proteome, including the analysis of changes in posttranslational modifications in histone proteins.

  6. Microbial leakage of Cavit, IRM, and Temp Bond in post-prepared root canals using two methods of gutta-percha removal: an in vitro study.

    Science.gov (United States)

    Balto, Hanan; Al-Nazhan, Saad; Al-Mansour, Khulood; Al-Otaibi, Moneera; Siddiqu, Yunus

    2005-08-15

    The aim of this study was to evaluate the integrity of the coronal seal of Temp-Bond and compare it to Cavit and IRM after post space preparation using S. faecalis as a microbial tracer. In addition, the affect of two methods of gutta percha removal on the apical seal of root canal fillings was also evaluated. Forty extracted human single rooted teeth were prepared chemomechanically and obturated with gutta percha and AH26 sealer cement using the lateral cold condensation technique to a standardized working length of 15 mm. About 10 mm of the coronal gutta-percha was removed with either Peeso-reamer or a hot plugger. The roots were divided into three experimental groups of 10 roots and a control group. Each experimental group was subdivided equally into two groups of 15 each according to the method of post space preparation. Cavit, IRM, and Temp-Bond were used to seal the access opening. Each root was fixed in a cuvette containing Tryptic Soya Broth which, covered 2 mm of the root apex. Bacterial suspension was introduced through pipette. Fresh bacterial suspension was added every week, and the system was monitored daily for the growth of microorganisms for a period of one month. The results showed there was no significant difference in terms of coronal leakage between the three coronal materials used (P=0.478), but the methods of gutta-percha removal did have an impact on the apical leakage (P=0.047). The mean value showed the Peeso-reamer provided less leakage compared to using a hot plugger during the 30-day experimental time period. It was concluded the temporary type of coronal seal of endodontically treated teeth will not prevent coronal leakage if left for a long period of time. In addition, permanent cementation of the post with the coronal restoration should be carried out as soon as possible to prevent recontamination of the root canal.

  7. Risk factors for gastroenteritis associated with canal swimming in two cities in the Netherlands during the summer of 2015: A prospective study

    Science.gov (United States)

    Sonder, Gerard; Parkkali, Saara; Brandwagt, Diederik; Fanoy, Ewout; Mughini-Gras, Lapo; Lodder, Willemijn; Ruland, Erik; Siedenburg, Evelien; Kliffen, Suzanne; van Pelt, Wilfrid

    2017-01-01

    Urban canal swimming events are popular in the Netherlands. In 2015, two city canal swimming events took place, in Utrecht (Utrecht Singel Swim, USS) and in Amsterdam (Amsterdam City Swim, ACS). This prospective study characterizes the health risks associated with swimming in urban waters. Online questionnaires were sent to 160 (USS) and 2,692 (ACS) participants, with relatives of participants who did not swim completing the questionnaire as a control. Swimming water specimens and stool specimens of diarrheic participants in the ACS group were analysed. A total of 49% of USS and 51% of ACS swimmers returned their questionnaires. Nine percent of USS swimmers and 4% of non-swimmers reported gastrointestinal complaints (aRR 2.1; 95% CI: 0.3–16), while a total of 31% of ACS swimmers and 5% of non-swimmers reported gastrointestinal complaints (aRR 6.3; 95% CI: 4.1–9.5). AGI risk among ACS participants was directly related to increasing number of mouthfuls of water swallowed. Various norovirus genotypes were detected in five out of seven stool specimens taken from ACS participants and in all three tested ACS water samples. We conclude that the AGI risk among open-water swimmers in urban areas depends on the circumstances around the event. The epidemiological curve, the statistical association between swimming and AGI, and the microbiological evidence for norovirus in stool and water specimens suggest that AGI outbreak after the ACS event was due to water contamination by multiple norovirus strains, which is possibly linked to sewage overflow due to prior heavy rainfall. There is need for more targeted preventive measurements and recommendations for organizers, municipal authorities and participants to prevent this reoccurring in the future. PMID:28369101

  8. 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.

  9. Nuclear Hybrid Energy Systems Regional Studies: West Texas & Northeastern Arizona

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Humberto E. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Chen, Jun [Idaho National Lab. (INL), Idaho Falls, ID (United States); Kim, Jong Suk [Idaho National Lab. (INL), Idaho Falls, ID (United States); McKellar, Michael George [Idaho National Lab. (INL), Idaho Falls, ID (United States); Deason, Wesley R [Idaho National Lab. (INL), Idaho Falls, ID (United States); Vilim, Richard B. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Bragg-Sitton, Shannon M. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Boardman, Richard D. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-04-01

    The primary objective of this study is to conduct a preliminary dynamic analysis of two realistic hybrid energy systems (HES) including a nuclear reactor as the main baseload heat generator (denoted as nuclear HES or nuclear hybrid energy systems [[NHES]) and to assess the local (e.g., HES owners) and system (e.g., the electric grid) benefits attainable by the application of NHES in scenarios with multiple commodity production and high penetration of renewable energy. It is performed for regional cases not generic examples based on available resources, existing infrastructure, and markets within the selected regions. This study also briefly addresses the computational capabilities developed to conduct such analyses, reviews technical gaps, and suggests some research paths forward.

  10. A study on the environmental friendliness of nuclear fuel cycle

    Energy Technology Data Exchange (ETDEWEB)

    Lee, K. J.; Lee, B. H.; Lee, S. Y.; Lim, C. Y.; Choi, Y. S.; Lee, Y. E.; Hong, D. S.; Cheong, J. H; Park, J. B.; Kim, K. K.; Cheong, H. Y; Song, M. C; Lee, H. J. [Korea Advanced Inst. of Science and Technology, Taejon (Korea, Republic of)

    1998-01-01

    The purpose of this study is to develop methodologies for quantifying environmental and socio-political factors involved with nuclear fuel cycle and finally to evaluate nuclear fuel cycle options with special emphasis given to the factors. Moreover, methodologies for developing practical radiological health risk assessment code system will be developed by which the assessment could be achieved for the recycling and reuse of scrap materials containing residual radioactive contamination. Selected scenarios are direct disposal, DUPIC(Direct use of PWR spent fuel in CANDU), and MOX recycle, land use, radiological effect, and non-radiological effect were chosen for environmental criteria and public acceptance and non-proliferation of nuclear material for socio-political ones. As a result of this study, potential scenarios to be chosen in Korea were selected and methodologies were developed to quantify the environmental and socio-political criteria. 24 refs., 27 tabs., 29 figs. (author)

  11. Opportunities for nuclear reaction studies at future facilities

    CERN Document Server

    Veselsky, Martin; Vujisicova, Nikoleta; Souliotis, Georgios A

    2016-01-01

    Opportunities for investigations of nuclear reactions at the future nuclear physics facilities such as radioactive ion beam facilities and high-power laser facilities are considered. Post-accelerated radioactive ion beams offer possibilities for study of the role of isospin asymmetry in the reaction mechanisms at various beam energies. Fission barrier heights of neutron-deficient nuclei can be directly determined at low energies. Post-accelerated radioactive ion beams, specifically at the future facilities such as HIE-ISOLDE, SPIRAL-2 or RAON-RISP can be also considered as a candidate for production of very neutron-rich nuclei via mechanism of multi-nucleon transfer. High-power laser facilities such as ELI-NP offer possibilities for nuclear reaction studies with beams of unprecedented properties. Specific cases such as ternary reactions or even production of super-heavy elements are considered.

  12. Nuclear-powered Hysat spacecraft: comparative design study

    Energy Technology Data Exchange (ETDEWEB)

    Raab, B.

    1975-08-01

    The study shows that the all-nuclear spacecraft can have a substantial weight advantage over a hybrid (nuclear/solar) or all-solar spacecraft, owing to a further reduction in power requirement, and to the elimination of such equipment as the sensor gimbal and rotating joint assemblies. Because the need for a sun-oriented section is eliminated, the all-nuclear spacecraft can be designed as a monolithic structure, with the sensor and other payload firmly secured in a fixed position on the structure. This enhances attitude stability while minimizing structural weight and eliminating the need for flexible fluid lines. Sensor motion can be produced, varied, and controlled within the limits specified by the study contractors by moving the entire spacecraft in the prescribed pattern. A simple attitude control system using available hardware suffices to meet all requirements.

  13. 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

    Objective. The purpose of this study was to analyze the correlation between direction of the infraorbital canal and maxillary width on frontal radiographs of dry human skulls. Material and methods. Forty-two symmetrical, dry human skulls (late adolescence and adult) with no dental or skeletal...

  14. Spatial and seasonal variations of the contamination within water body of the Grand Canal, China

    NARCIS (Netherlands)

    Wang, X.L.; Han, Jingyi; Xu, L.G.; Zhang, Q.

    2010-01-01

    To delineate the character of contaminations in the Grand Canal, China, a three-year study (2004-2006) was conducted to investigate variations the water quality in the canal. Results showed that the variation of water quality within the Grand Canal was of there is remarkable spatial and seasonal het

  15. Determinants for a successful Sémont maneuver: an in-vitro study with a semicircular canal model

    Directory of Open Access Journals (Sweden)

    Dominik Obrist

    2016-09-01

    Full Text Available Objective: To evaluate the effect of time between the movements/steps, angle of body movements as well as the angular velocity of the maneuvers in an in-vitro model of a semicircular canal (SCC to improve the efficacy of the Sémont maneuver in benign paroxysmal positional vertigo (BPPV.Methods: Sémont maneuvers were performed on an in-vitro SCC model. Otoconia trajectories were captured by a video camera. The effects of time between the movements, angles of motion (0°, 10°, 20°, 30° below the horizontal line, different angular velocities (90, 135, 180°/s and otoconia size (36 and 50µm on the final position of the otoconia in the SCC were tested.Results: Without extension of the movements beyond the horizontal, the in-vitro experiments (with particles corresponding to 50 m diameter did not yield successful canalith repositioning. If the movements were extended by 20° beyond the horizontal position, Sémont maneuvers were successful with resting times of at least 16 s. For larger extension angles the required time decreased. However, for smaller particles (36 m the required time doubled. The angular maneuver velocity (tested between 90 and 180°/s did not have a major impact on the final position of the otoconia.Interpretation: The two primary determinants for success of the Sémont maneuver are the time between the movements and the extension of the movements beyond the horizontal. The time between the movements should be at least 45 s. Angles of 20° or more below horizontal line (so-called Sémont ++ should increase the success rate of SM.

  16. Studying Nuclear Receptor Complexes in the Cellular Environment.

    Science.gov (United States)

    Schaufele, Fred

    2016-01-01

    The ligand-regulated structure and biochemistry of nuclear receptor complexes are commonly determined by in vitro studies of isolated receptors, cofactors, and their fragments. However, in the living cell, the complexes that form are governed not just by the relative affinities of isolated cofactors for the receptor but also by the cell-specific sequestration or concentration of subsets of competing or cooperating cofactors, receptors, and other effectors into distinct subcellular domains and/or their temporary diversion into other cellular activities. Most methods developed to understand nuclear receptor function in the cellular environment involve the direct tagging of the nuclear receptor or its cofactors with fluorescent proteins (FPs) and the tracking of those FP-tagged factors by fluorescence microscopy. One of those approaches, Förster resonance energy transfer (FRET) microscopy, quantifies the transfer of energy from a higher energy "donor" FP to a lower energy "acceptor" FP attached to a single protein or to interacting proteins. The amount of FRET is influenced by the ligand-induced changes in the proximities and orientations of the FPs within the tagged nuclear receptor complexes, which is an indicator of the structure of the complexes, and by the kinetics of the interaction between FP-tagged factors. Here, we provide a guide for parsing information about the structure and biochemistry of nuclear receptor complexes from FRET measurements in living cells.

  17. Kiwi: An Evaluated Library of Uncertainties in Nuclear Data and Package for Nuclear Sensitivity Studies

    Energy Technology Data Exchange (ETDEWEB)

    Pruet, J

    2007-06-23

    This report describes Kiwi, a program developed at Livermore to enable mature studies of the relation between imperfectly known nuclear physics and uncertainties in simulations of complicated systems. Kiwi includes a library of evaluated nuclear data uncertainties, tools for modifying data according to these uncertainties, and a simple interface for generating processed data used by transport codes. As well, Kiwi provides access to calculations of k eigenvalues for critical assemblies. This allows the user to check implications of data modifications against integral experiments for multiplying systems. Kiwi is written in python. The uncertainty library has the same format and directory structure as the native ENDL used at Livermore. Calculations for critical assemblies rely on deterministic and Monte Carlo codes developed by B division.

  18. 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.

  19. A maxillary central incisor with four root canals

    Directory of Open Access Journals (Sweden)

    Fábio de Almeida-Gomes

    2012-01-01

    Full Text Available The objective of the present study is to present a case report of endodontic treatment of a maxillary central incisor with 1 root and 4 root canals. The success of endodontic treatment requires knowledge of dental anatomy and its variations. This clinical article reports an unusual anatomy detected in a maxillary central incisor with 4 root canals with an associated periapical lesion. The incidence of 4 root canals in this tooth is rare. However, it must be taken into consideration, the clinical and radiographic evaluations during the endodontic treatment in order to enhance the diagnostic. Many times, the presence of a supernumerary canal is noticed only after canal treatment due to continuing post-operative discomfort or treatment failure.

  20. Study of the derivative expansions for the nuclear structure functions

    CERN Document Server

    Simo, I Ruiz

    2008-01-01

    We study the convergence of the series expansions sometimes used in the analysis of the nuclear effects in Deep Inelastic Scattering (DIS) proccesses induced by leptons. The recent advances in statistics and quality of the data, in particular for neutrinos calls for a good control of the theoretical uncertainties of the models used in the analysis. Using realistic nuclear spectral functions which include nucleon correlations, we find that the convergence of the derivative expansions to the full results is poor except at very low values of $x$.

  1. Nuclear electric propulsion mission engineering study. Volume 1: Executive summary

    Science.gov (United States)

    1973-01-01

    Results of a mission engineering analysis of nuclear-thermionic electric propulsion spacecraft for unmanned interplanetary and geocentric missions are summarized. Critical technologies associated with the development of nuclear electric propulsion (NEP) are assessed. Outer planet and comet rendezvous mission analysis, NEP stage design for geocentric and interplanetary missions, NEP system development cost and unit costs, and technology requirements for NEP stage development are studied. The NEP stage design provides both inherent reliability and high payload mass capability. The NEP stage and payload integration was found to be compatible with the space shuttle.

  2. Polyacrylamide Transport in Water Delivery Canals

    Science.gov (United States)

    Chen, L.; Zhu, J.; Young, M.

    2007-12-01

    Linear, anionic polyacrylamide (PAM) is being considered in the western United States as a technology to reduce seepage in unlined water delivery canals. A broad laboratory and field testing program has been undertaken to understand the benefits and potential environmental impacts of PAM use. The ability to predict the fate and transport of PAM in water delivery canals could prove to be a useful planning tool for PAM application. However, one key area of uncertainty of this type of canal treatment is the hydration, reaction, and settling rates of PAM after the dry powder is added to the canal water. In this study, we have developed a model that incorporates a number of known physical and chemical processes that can affect PAM transport, such as convection, dispersion, dissolution, flocculation, and settling, while solving the governing convection-dispersion transport equation. The model uses a mixed analytical and advanced numerical approach, and implements a transient partitioning of PAM mass between the canal water, the substrate soil, and potentially to open water bodies downstream of the application point. All source terms are modeled based on physical and chemical mechanisms as well as laboratory or field determined parameters. To more closely simulate field treatment of some canals, where PAM application moves upstream in time, the model is capable of implementing either a fixed or mobile upper boundary. In the latter treatment, the PAM can be added discretely or continuously in both time and space. A number of test situations have been simulated thus far, including theoretical and hypothetical cases for a wide range of conditions. The model also performed well when predicting PAM concentrations from a full-scale canal treatment experiment. The model provides a useful tool for predicting PAM fate and transport in water delivery canals, and therefore can play an important role in evaluating the efficacy of PAM application for water resources management

  3. Study on efficiency of DCP for nuclear hydrogen production

    Institute of Scientific and Technical Information of China (English)

    LIN Qian; CAO Xue-Wu; JIANG Rui-Peng; ZHANG Xu

    2005-01-01

    With many advantages, hydrogen is considered as the fuel of the future. But there is no natural resource of hydrogen and it must be produced by other kinds of energy. As for the primary energy, nuclear energy is a promising alternative. Using heat from nuclear reactor to produce hydrogen is receiving more and more concerns in recent years. This paper mainly emphasizes the study of the direct contact pyrolysis (DCP) of methane using heat from nuclear reactor. A facility was designed to investigate the efficiency of DCP process in certain conditions. The experimental results show that this process produces only hydrogen and carbon. The conversion efficiency increases with temperature and residence time, but decreases as flow rate increases. The highest efficiency of DCP obtained in this experiment is about 22%.

  4. A Study on Human Resources Development in Nuclear Field

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Keehwan; Lee, M. K.; Kim, S. S.; Nam, J. H.; Won, B. C.; Lee, D. S; Hwang, I. A.; Seo, M. W.

    2011-11-15

    The study encompasses 4 major parts, each results being described here under: Various policy alternatives through supply-demand analysis of domestic nuclear skilled manpower are suggested. Human resources development programs of main educational organizations in domestic and overseas are comprehensively reviewed. Establishment of 'Integrated Management Organization' which can combine and manage domestic educational organizations' educational functions is necessary to efficiently deal with the increased educational demand and the shift of educational paradigm from supply-driven to needs-driven education and to make nuclear energy export sustainable. And road map on human resource development to efficiently accomplish 'Integrated Management Organization's mission is suggested. It is provided that an overall strategies for the reasonable educational program reflecting the good practices with their implications in overseas nuclear education programs.

  5. Nuclear Minerals Plants in Brazil-Case Studies

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This paper presents the process flow sheet of the main nuclear industrial units in Brazil and discusses some solvent extraction technical support required for these plants. The Center for the Development of Nuclear Technology-CDTN has been investigating alternative ways to supply the nuclear industry in order to improve the industrial processes. Some case study examples are presented, Emulsion from Uranium has caused continuous changes in the composition of pregnant liquor mainly in the sulfate and chloride concentrations. After some water recirculation cycles, a decrease in the uranium extraction efficiency was noted which was followed by the formation of stable emulsion at the uranium extraction stage. Itataia Ufanium Developments were performed in a pilot plant for Itataia ore. This ore has the uranium mineral associated to the phosphate. The process consists of four main steps: 1) phosphate concentration, 2) chemical digestion of the concentrate to produce phosphoric acid with dissolved uranium, 3) uranium recovery, and 4) phosphoric acid purification by solvent extraction.

  6. 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

  7. 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

  8. Study of Particle Production and Nuclear Fragmentation in Relativistic Heavy-Ion Collisions in Nuclear Emulsions

    CERN Multimedia

    2002-01-01

    % EMU11 \\\\ \\\\ We propose to use nuclear emulsions for the study of nuclear collisions of $^{207}$Pb, $^{197}$Au, and any other heavy-ion beams when they are available. We have, in the past, used $^{32}$S at 200A~GeV and $^{16}$O at 200A and 60A~GeV from CERN (Experiment EMU08) and at present the analysis is going on with $^{28}$Si beam from BNL at 14.5A~GeV. It will be important to compare the previous and the present investigations with the new $^{207}$Pb beam at 60-160A~GeV. We want to measure in nuclear emulsion, on an event by event basis, shower particle multiplicity, pseudorapidity density and density fluctuations of charged particles, charge multiplicity and angular distributions of projectile fragments, production and interaction cross-sections of heavily ionizing particles emitted from the target fragmentation. Special emphasis will be placed on the analysis of events produced in the central collisions which are selected on the basis of low energy fragments emitted from the target excitation. It woul...

  9. 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.)

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

    Directory of Open Access Journals (Sweden)

    Kavita Tarale

    2013-01-01

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

  11. Spent nuclear fuel project design basis capacity study

    Energy Technology Data Exchange (ETDEWEB)

    Cleveland, K.J.

    1998-07-22

    A parametric study of the Spent Nuclear Fuel Project system capacity is presented. The study was completed using a commercially available software package to develop a summary level model of the major project systems. A base case, reflecting the Fiscal Year 1998 process configuration, is evaluated. Parametric evaluations are also considered, investigating the impact of higher fuel retrieval system productivity and reduced shift operations at the canister storage building on total project duration.

  12. Preparation of feasibility studies for nuclear power plants; Elaboracion de estudios de viabilidad de centrales nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Andujar Sagredo, R.

    2013-07-01

    The feasibility study falls within the pre-purchase of a new nuclear plant jobs. This is a key process for the early identification of risks associated with the construction of the same, and the investment needed and the time within which such investment return, taking into account that this is a complex industrial project with an iron control and accurate high inputs of capital. Set the risks in these early stages of the project can make the difference in keeping both the budget and the execution time initially considered.

  13. Cervical spinal canal narrowing in idiopathic syringomyelia

    Energy Technology Data Exchange (ETDEWEB)

    Struck, Aaron F. [Massachusetts General Hospital, Department of Neurology, Boston, MA (United States); Carr, Carrie M. [Mayo Clinic, Department of Radiology, Rochester, MN (United States); Shah, Vinil [University of California San Francisco, Department of Radiology, San Francisco, CA (United States); Hesselink, John R. [University of California San Diego, Department of Radiology, San Diego, CA (United States); Haughton, Victor M. [University of Wisconsin, Department of Radiology, Madison, WI (United States)

    2016-08-15

    The cervical spine in Chiari I patient with syringomyelia has significantly different anteroposterior diameters than it does in Chiari I patients without syringomyelia. We tested the hypothesis that patients with idiopathic syringomyelia (IS) also have abnormal cervical spinal canal diameters. The finding in both groups may relate to the pathogenesis of syringomyelia. Local institutional review boards approved this retrospective study. Patients with IS were compared to age-matched controls with normal sagittal spine MR. All subjects had T1-weighted spin-echo (500/20) and T2-weighted fast spin-echo (2000/90) sagittal cervical spine images at 1.5 T. Readers blinded to demographic data and study hypothesis measured anteroposterior diameters at each cervical level. The spinal canal diameters were compared with a Mann-Whitney U test. The overall difference was assessed with a Friedman test. Seventeen subjects were read by two reviewers to assess inter-rater reliability. Fifty IS patients with 50 age-matched controls were studied. IS subjects had one or more syrinxes varying from 1 to 19 spinal segments. Spinal canal diameters narrowed from C1 to C3 and then enlarged from C5 to C7 in both groups. Diameters from C2 to C4 were narrower in the IS group (p < 0.005) than in controls. The ratio of the C3 to the C7 diameters was also smaller (p = 0.004) in IS than controls. Collectively, the spinal canal diameters in the IS were significantly different from controls (Friedman test p < 0.0001). Patients with IS have abnormally narrow upper and mid cervical spinal canal diameters and greater positive tapering between C3 and C7. (orig.)

  14. Comparative evaluation of canal transportation, centering ability, and remaining dentin thickness between WaveOne and ProTaper rotary by using cone beam computed tomography: An in vitro study

    Science.gov (United States)

    Jain, Aditi; Asrani, Hemant; Singhal, Abhinav Chand; Bhatia, Taranjeet Kaur; Sharma, Vaibhav; Jaiswal, Pragya

    2016-01-01

    Aims: To compare the canal transportation, centering ability, and remaining dentin thickness of WaveOne and ProTaper systems using cone beam computed tomography. Subjects and Methods: Forty extracted human single-rooted premolars were used in the present study. Preinstrumentation scanning of all teeth was taken; canal curvatures were calculated, and the samples were randomly divided into two groups, with twenty samples in each group; one group was instrumented with WaveOne system and the other group with ProTaper rotary system. Postinstrumentation scans were performed, and the two scans were compared to determine canal transportation, centering ability, and remaining dentin thickness at 3 mm, 6 mm, and 9 mm from the root apex. Statistical Analysis Used: Student's unpaired t-test. Results: Using Student's unpaired t-test, results were as follows: for canal transportation, Group 1 showed significant difference at 3 mm and 6 mm and insignificant difference at 9 mm while Group 2 showed insignificant difference in all the three regions. For centering ability and remaining dentin thickness, Group 1 showed insignificant difference at 3 mm and 9 mm while significant difference at 6 mm was obtained. When comparison of remaining dentin thickness was done at three levels using two groups WaveOne and ProTaper, there was no significant difference between two groups. Conclusions: (1) WaveOne single reciprocation file system respected better canal anatomy better than ProTaper. (2) Individually, centering ability of WaveOne was better at 3 mm, 6 mm, and 9 mm levels. (3) However, ProTaper individually was better centered at 3 mm (apical third) and 9 mm (coronal 3rd) levels than 6 mm level (middle third). PMID:27656063

  15. Nuclear structure studies in JUSTIPEN and EFES activities

    Science.gov (United States)

    Itagaki, Naoyuki

    2009-10-01

    JUSTIPEN: Japan-US Theory Institute for Physics with Exotic Nuclei was launched in June 2006. JUSTIPEN has been established in order to facilitate collaborations between U.S. and Japanese scientists whose main research thrust is in the area of the physics of exotic nuclei. More than 40 nuclear scientists in U.S. have visited Japan in three years, and the many collaborations are established. I briefly summarize the JUSTIPEN activity from the Japanese side. There is counterpart program for the Japanese scientists. International Research Network for Exotic Femto Systems (EFES) was selected as one of the Core-to-Core Programs of Japan Society for the Promotion of Science (JSPS). This is the program to send Japanese nuclear scientists to U.S., Germany, France, Italy, Norway, and Finland and to promote the international collaborations in the field of nuclear study. Many joint workshops were held with partner countries. To operate these international programs, University of Tokyo and RIKEN agreed to corporate with each other and established Todai-RIKEN Joint International Program for Nuclear Physics (TORIJIN) in June 2006. I summarize the activities in three years, and I also mention about the relation between these activities and my personal research -- many-body correlations in light nuclei.

  16. Study on the Internationalization of Korean Nuclear Journals

    Energy Technology Data Exchange (ETDEWEB)

    Chun, Y. C.; Yoo, J. B. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    2006-07-01

    This paper is intended to provide some thoughts for a listing of the Korean nuclear journals in the Science Citation Index(SCI), by an analysis of indicators based on the data gathered from relevant literature : Journal of Korean Nuclear Society(JKNS) and Nuclear Engineering and Technology (NET) as cited in the SCI source journal. The study examines as an indicator the number of papers in the JKNS and NET that have been cited by KAERI researchers in the SCI Source Journal (to the end of August 2006). This paper also gives a review of the statistics provided by the Institute for Scientific Information (ISI), as an authoritative source for an evaluation of a global cataloguing of scientific and technical journals, and suggests a view for a listing of the Korean nuclear journals in the SCI by a review of associated selection criteria and methods. It concludes there is a need to increase the number of citations in the SCI source journals of the NET papers to be published from the most recent previous two years.

  17. Application of nuclear logging to porosity studies in Itaborai basin

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Milena F.S.; Lima, Inaya; Lopes, Ricardo Tadeu, E-mail: milena@lin.ufrj.br, E-mail: inaya@lin.ufrj.br, E-mail: ricardo@lin.ufrj.br [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Lab. de Instrumentacao Nuclear; Ferrucio, Paula Lucia; Borghi, Leonardo, E-mail: ferrucio@acd.ufrj.br, E-mail: borghi@ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Geociencias. Dept. de Geologia; Abreu, Carlos Jorge, E-mail: jo_abreu@unb.br [Universidade de Brasilia (UnB), DF (Brazil). Inst. de Geociencias

    2011-07-01

    Nuclear logging provides information on bulk density and porosity variations by measuring the intensity of the scattered radiation induced on the formation by radioactive sources. In this study, nuclear logging was employed to analyze the pore-space system of the 2-ITAB-1-RJ well placed on the Itaborai limestone basin, in the state of Rio de Janeiro. This is one of the smallest sedimentary basin in Brazil and it is formed by clastic deposits and travertine limestone rocks which are fractured. Understanding the pore-space system of carbonate rocks has become important subject for the oil industry, specially in Brazil. A Density Gamma Probe (LSD) and a Neutron Probe (NEUT) were used for data acquisition, which nuclear logging was carried out in part of the well, with continuous detection for about 50 m of deep. The detection speed was 4 m/min for the LSD and 5 m/min for the NEUT. The results obtained by nuclear logging showed that the 2-ITAB-1-RJ well consists of three different intervals with rocks ranging from low to moderate porosity present in travertine, marls and gneisses. (author)

  18. Virtual reality at nuclear issues : a review study

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Marcio Henrique da; Legey, Ana Paula; Mol, Antonio Carlos de A., E-mail: marciohenrique@lmp.ufrj.br, E-mail: ana.legey@pq.cnpq.br, E-mail: mol@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    Recently, several applications using concepts related to virtual reality has been proposed to help on solving issues of great interest in Nuclear Engineering. Among them are power plant's control rooms simulators; measurement of the estimated radiation dose in a nuclear power plant; use of game engines to create virtual environments to support evacuation planning of buildings and circulation in areas subjected to radiation; development of a man - machine interface based on speech recognition; virtual control tables for simulation of nuclear power plants; evacuation plans support; security teams training and evaluation of physical protection barriers; ergonomic evaluation of control rooms, and other ones. Many of these applications are developed at Instituto de Engenharia Nuclear (IEN), having their results published in form of articles in periodicals and conferences. This article presents a review of some of these studies showing the evolution in the use of these concepts, describing some of its results and showing prospects for future applications that can make use of virtual reality technology. (author)

  19. 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

  20. 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

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

    Science.gov (United States)

    2017-01-01

    Background Successful root canal treatment depends on proper cleaning, disinfecting and shaping of the root canal space. Pulpless teeth have lower dentin microhardness value compared to that of vital teeth. A material which can cause change in dentin composition may affect the microhardness. Thus the aim of this study was to evaluate and compare the effect of two root canal sealers on dentin microhardness. Material and Methods Forty two single rooted teeth were selected and divided into 3 equal groups; Apexit, iRootSP and control groups (n=14) Each group was then divided into 2 subgroups according to the post evaluation period; 1 week and 2 months (n=7). Root canal procedure was done in the experimental groups and obturation was made using either; Apexit, iRootSP or left unprepared and unobturated in the control group. Roots were sectioned transversely into cervical, middle and apical segments. The three sections of each root were mounted in a plastic chuck with acrylic resin. The coronal dentin surfaces of the root segments werepolished. Microhardness of each section was measured at 500 µm and 1000 µm from the canal lumen. Results Four way-ANOVA revealed that different tested sealer materials, canal third, measuring distance from the pulp and time as independent variables had statistically non significant effect on mean microhardness values (VHN) at p≤0.001. Among iRootSP groups there was a statistically significant difference between iRoot SP at coronal root portion (87.79±17.83) and iRoot SP at apical root portion (76.26±9.33) groups where (p=0.01). IRoot SP at coronal canal third had higher statistically significant mean microhardness value (87.79±17.83) compared to Apexit at coronal third (73.61±13.47) where (p=0.01). Conclusions Root canal sealers do not affect dentin microhardness. Key words:Root canal, dentin, sealers, microhardness, bioceramic. PMID:28149466

  2. Comprehensive Technical Report, General Electric Direct-Air-Cycle Aircraft Nuclear Propulsion Program; Aircraft Nuclear Propulsion Application Studies

    Energy Technology Data Exchange (ETDEWEB)

    Comassar, S.

    1962-04-30

    This volume is one of twenty-one summarizing the Aircraft Nuclear Propulsion Program of the General Electric Company. This portion describes the studies of advanced applications of nuclear reactors that were performed, including various types of aircraft, missiles, space vehicles, ships, and portable power plants.

  3. Isospin and symmetry energy study in nuclear EOS

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    This paper summarizes the isoscaling and isospin related studies in asymmetry nuclear reactions by different dynamic and sta tistical models. Isospin dependent quantum molecular dynamics model (IQMD) and lattice gas model (LGM) are used to study the isoscaling properties and isoscaling parameters dependence on incident energies, impact parameters, temperature and other parameters. In the LGM model, the signal of phase transition has been found in free neutron (proton) chemical potential dif ference Δμn or Δμp as a function of temperature, or in free neutron and proton chemical potential difference Δμn-Δμp. Density dependence of symmetry energy coefficient Csym(ρ/ρ0) is also studied in the frame of LGM, with the potential parameters which can reproduce the nuclear ground state property, soft density dependence of symmetry energy is deduced from the sim ulation results. Giant dipole resonance (GDR) induced by isospin asymmetry in entrance channel is also studied via IQMD model, and the dynamic dipole resonance shows isospin sensitivity on the isospin asymmetry of entrance channel and sym metry energy of the nuclear equation of state (EOS). GDR can also be regarded as a possible isospin sensitive signature.

  4. Study of nuclear recoils in liquid argon with monoenergetic neutrons

    CERN Document Server

    Regenfus, C; Amsler, C; Creus, W; Ferella, A; Rochet, J; Walter, M

    2012-01-01

    For the development of liquid argon dark matter detectors we assembled a setup in the laboratory to scatter neutrons on a small liquid argon target. The neutrons are produced mono-energetically (E_kin=2.45 MeV) by nuclear fusion in a deuterium plasma and are collimated onto a 3" liquid argon cell operating in single-phase mode (zero electric field). Organic liquid scintillators are used to tag scattered neutrons and to provide a time-of-flight measurement. The setup is designed to study light pulse shapes and scintillation yields from nuclear and electronic recoils as well as from {\\alpha}-particles at working points relevant to dark matter searches. Liquid argon offers the possibility to scrutinise scintillation yields in noble liquids with respect to the populations of the two fundamental excimer states. Here we present experimental methods and first results from recent data towards such studies.

  5. Nuclear structure studies at Saha Institute of Nuclear Physics using gamma detector arrays

    Indian Academy of Sciences (India)

    P Banerjee

    2001-07-01

    In-beam gamma-ray spectroscopy, carried out at the Saha Institute of Nuclear Physics in the recent past, using heavy-ion projectiles from the pelletron accelerator centres in the country and multi-detector arrays have yielded significant data on the structure of a large number of nuclei spanning different mass regions. The experiments included the study of two-fold -coincidence events for establishing decay schemes, directional correlation of oriented nuclei (DCO) for help in spin assignments and Doppler shift attenuation for lifetime information. The studies have led to the observation of rotational sequences of states in nuclei near closed shell in the mass = 110 region, vibrational spectra in nuclei with ∼ 60, interplay between single-particle and collective modes of excitation in the doubly-odd bromine isotopes, decoupled bands with large quadrupole deformation in 77Br, shape transition with rotational frequency within a band in 138Pm and octupole collectivity in 153Eu. Particle-rotor-model and cranked-shell-model calculations have been carried out to provide an understanding of the underlying nuclear structure

  6. Shaping ability of reciprocating motion of WaveOne and HyFlex in moderate to severe curved canals: A comparative study with cone beam computed tomography

    Science.gov (United States)

    Simpsy, Gurram Samuel; Sajjan, Girija S.; Mudunuri, Padmaja; Chittem, Jyothi; Prasanthi, Nalam N. V. D.; Balaga, Pankaj

    2016-01-01

    Introduction: M-Wire and reciprocating motion of WaveOne and controlled memory (CM) wire) of HyFlex were the recent innovations using thermal treatment. Therefore, a study was planned to evaluate the shaping ability of reciprocating motion of WaveOne and HyFlex using cone beam computed tomography (CBCT). Methodology: Forty-five freshly extracted mandibular teeth were selected and stored in saline until use. All teeth were scanned pre- and post-operatively using CBCT (Kodak 9000). All teeth were accessed and divided into three groups. (1) Group 1 (control n = 15): Instrumented with ProTaper. (2) Group 2 (n = 15): Instrumented with primary file (8%/25) WaveOne. (3) Group 3 (n = 15): Instrumented with (4%/25) HyFlex CM. Sections at 1, 3, and 5 mm were obtained from the pre- and post-operative scans. Measurement was done using CS3D software and Adobe Photoshop software. Apical transportation and degree of straightening were measured and statistically analyzed. Results: HyFlex showed lesser apical transportation when compared to other groups at 1 and 3 mm. WaveOne showed lesser degree of straightening when compared to other groups. Conclusion: This present study concluded that all systems could be employed in routine endodontics whereas HyFlex and WaveOne could be employed in severely curved canals. PMID:27994323

  7. In vitro comparison of passive and continuous ultrasonic irrigation in curved root canals

    Science.gov (United States)

    Castelo-Baz, Pablo; Varela-Patiño, Purificación; Cantatore, Giuseppe; Domínguez-Perez, Ana; Ruíz-Piñón, Manuel; Martín-Biedma, Benjamín

    2016-01-01

    Background The efficacy of endodontic irrigation procedures can be compromised by the complexity of the root canal system. Delivering irrigants to the apical third of curved canals presents a particular challenge to endodontists. This study compared the effects of two ultrasonic irrigation techniques on the penetration of sodium hypochlorite into the main canal and simulated lateral canals of curved roots in extracted teeth. Material and Methods Two sets of simulated lateral canals were created at 2, 4, and 6 mm from the working length in 60 single-rooted teeth (6 canals/tooth, n = 360 canals). The teeth were randomly divided into three experimental irrigation groups: group 1 (n = 20), positive pressure irrigation (PPI); group 2 (n = 20), passive ultrasonic irrigation (PUI); and group 3 (n = 20), continuous ultrasonic irrigation (CUI). To assess the irrigation solution penetration, 20% Chinese ink (Sanford Rotring GmbH, Hamburg, Germany) was added to a 5% sodium hypochlorite solution and delivered into the curved root canals. The penetration of contrast solution into the simulated lateral canals was scored by counting the number of lateral canals (0-2) penetrated to at least 50% of the total length. Results The CUI group showed significantly higher (P irrigant penetration into the lateral canals and into the apical third of the main canals. The PPI group showed significantly lower sodium hypochlorite penetration (P irrigant penetration was observed in the PUI group than the PPI group. Conclusions Using CUI as the final rinse significantly increased the penetration of irrigant solution into the simulated lateral canals and apical third of curved roots. Key words:Continuous ultrasonic irrigation, curved root canals, passive ultrasonic irrigation, positive pressure irrigation, root canal irrigation.

  8. Special nuclear material detection studies with the SMANDRA mobile system

    OpenAIRE

    Cester, D.; Nebbia, G.; Stevanato, L.; G. Viesti; Neri, F; Petrucci, S; S. Selmi; Tintori, C.; PEERANI, P; Tomanin, Alice

    2012-01-01

    The detection of special nuclear material has been studied with the SMANDRA mobile inspection system used both as a high sensitivity passive neutron/gamma spectroscopic tool and as an active inspection device using tagged neutrons. The detection of plutonium samples is possible with passive interrogation, the passive detection of uranium being much more difficult because of the low neutron yield and of the easiness of shielding the gamma rays. However, we show that active interrogation with t...

  9. 27Al nuclear quadrupole resonance study of crystalline aluminosilicates

    Science.gov (United States)

    Lee, Donghoon; Bray, P. J.

    27Al NQR responses have been obtained from the three different forms of crystalline Al 2SiO 5, andalusite, kyanite, and sillimanite, by a very sensitive Robinson-type continuous wave NQR spectrometer at 77 K or at room temperature. From the NQR responses the values of Qcc and of η were determined for all the aluminum coordinations in the powdered samples. The values are compared with those obtained by nuclear magnetic resonance studies of single crystals.

  10. Bacterial coronal leakage after obturation with three root canal sealers.

    Science.gov (United States)

    Timpawat, S; Amornchat, C; Trisuwan, W R

    2001-01-01

    The purpose of this study was to compare the bacterial leakage of root canals obturated with three root canal sealers, using Endodontalis faecalis as a microbial tracer to determine the length of time for bacteria to penetrate through the obturated root canal to the root apex. Seventy-five, single-rooted teeth with straight root canals had the crown cut off at the cementoenamel junction. Root canals were instrumented by a step-back technique. The prepared teeth were randomly divided into 3 groups of 19 teeth each and another 2 groups as positive and negative controls (9 teeth each). The experimental groups were dependent on the sealer used: AH-Plus, Apexit, and Ketac-Endo. The root canals were obturated using a lateral condensation technique. After 24 h the teeth were attached to microcentrifuge tubes with 2 mm of the root apex submerged in Brain Heart Infusion broth in glass test tubes. The coronal portions of the root canal filling materials were placed in contact with E. faecalis. The teeth were observed for bacterial leakage daily for 30 and 60 days. With the chi2 test for comparing pairs of groups at the 0.05 level (p 0.06), but Apexit had significantly higher leakage (p 0.05), but Apexit leaked more than AH-Plus. The conclusion drawn from this experiment was that epoxy resin root canal sealer was found to be more adaptable to the root canal wall and filling material than a calcium hydroxide sealer when bacterial coronal leakage was studied.

  11. Facial Canal Dehiscence in Patients with Chronic Otitis Surgery

    Directory of Open Access Journals (Sweden)

    Ahmet Uluat

    2016-04-01

    Full Text Available Aim: To examine facial canal status in patients with chronic otitis media (COM surgery and to detect the relation between facial canals dehiscence (FCD with middle ear pathology in these patients. Material and Method: The surgery data of patients who were subjected to tympanoplasty with or without mastoidectomy and radical mastoidectomy due to COM were analyzed retrospectively from January 2006 to December 2012. In addition to demonstrative data of the patients, status of facial canal and preoperative diagnoses of patients, type of the operation performed, status of middle ear, number of surgeries, existence of cholesteatoma, existence of ossicular chain defect, lateral canal defect and dura defect were assessed and the relation thereof with facial canal dehiscence (FCD was analyzed statistically. Results: Seven hundred ninety six patients were included in the study. FCD was detected in 10.05% of the patients. FCD was most frequently observed in the tympanic segment. It was found out that there was a statistically significant relationship of middle ear pathology, cholesteatoma, revision surgery, lateral semicircular canal and ossicular chain defect with FCD. Discussion: COM diagnosed patients may have defect in facial canal according to their preoperative diagnoses, middle ear pathologies, number of operations and ossicular chain defects. These patients should be applied a more careful surgery and closely followed up in postoperative periods.

  12. Faraday ghosts depolarization canals in the Galactic radio emission

    CERN Document Server

    Shukurov, A M; Shukurov, Anvar; Berkhuijsen, Elly M.

    2003-01-01

    Narrow, elongated regions of very low polarized intensity -- so-called canals -- have recently been observed by several authors at decimeter wavelengths in various directions in the Milky Way, but their origin remains enigmatic. We show that the canals arise from depolarization by differential Faraday rotation in the interstellar medium and that they represent level lines of Faraday rotation measure RM, a random function of position in the sky. Statistical properties of the separation of canals depend on the autocorrelation function of RM, and so provide a useful tool for studies of interstellar turbulence.

  13. [The study of proliferative epithelial activity in cholesteatoma of the middle ear during cytomorphophotometry].

    Science.gov (United States)

    Amador, J M; Esquivias, J J; Ciges, M

    1994-01-01

    Epithelial proliferation in colesteatoma and its influence on the subepithelial inflammatory reaction was studied using morphometry and nuclear photometry of specimens. Twenty specimens of colesteatoma and 15 specimens of skin from the external auditory canal were examined. Nuclear content was greater in the basal cells of colesteatoma epithelium than in the basal cells of external auditory canal epithelium, suggesting increased proliferative activity. This activity was found to be reted to the inflammatory infiltrate of the conjunctive tissue and varied in different specimens.

  14. Social impacts of hazardous and nuclear facilities and events: Implications for Nevada and the Yucca Mountain high-level nuclear waste repository; [Final report

    Energy Technology Data Exchange (ETDEWEB)

    Freudenburg, W.R. [Wisconsin Univ., Madison, WI (United States); Carter, L.F.; Willard, W. [Washington State Univ., Pullman, WA (United States); Lodwick, D.G. [Miami Univ., Oxford, OH (United States); Hardert, R.A. [Arizona State Univ., Tempe, AZ (United States); Levine, A.G. [State Univ. of New York, Buffalo, NY (United States). Dept. of Sociology; Kroll-Smith, S. [New Orleans Univ., LA (United States); Couch, S.R. [Pennsylvania State Univ., University Park, PA (United States); Edelstein, M.R. [Ramapo College, Mahwah, NJ (United States)

    1992-05-01

    Social impacts of a nuclear waste repository are described. Various case studies are cited such as Rocky Flats Plant, the Feed Materials Production Center, and Love Canal. The social impacts of toxic contamination, mitigating environmental stigma and loss of trust are also discussed.

  15. 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...

  16. Evaluation of microcrack formation in root canals after instrumentation with different NiTi rotary file systems: a scanning electron microscopy study.

    Science.gov (United States)

    Çiçek, Ersan; Koçak, Mustafa Murat; Sağlam, Baran Can; Koçak, Sibel

    2015-01-01

    The aim of this study was to evaluate the dentinal microcrack formation of ProTaper Universal, ProTaper Next, and WaveOne. Sixty extracted mandibular molars were selected. The mesial roots were resected and randomly divided into four groups (n = 15). The canals were prepared with hand files (group 1), ProTaper Universal (group 2), ProTaper Next (group 3), and WaveOne (group 4) instrument systems. The roots were separated horizontally at 3, 6, and 9 mm from the apex. Digital images were captured at ×40 magnification using scanning electron microscopy to detect microcrack formation. Statistical analysis was performed by Pearson Chi-square test. The prevalence of microcracks in group 2, group 3, and group 4 were significantly higher when compared to group 1 (p  0.05) in all sections. All instruments caused microcracks except for hand file. The highest percentage of microcrack was recorded in 3 mm section for all groups.

  17. 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.

  18. 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.

  19. Apparent Resistivity and Estimated Interaction Potential of Surface Water and Groundwater along Selected Canals and Streams in the Elkhorn-Loup Model Study Area, North-Central Nebraska, 2006-07

    Science.gov (United States)

    Teeple, Andrew P.; Vrabel, Joseph; Kress, Wade H.; Cannia, James C.

    2009-01-01

    In 2005, the State of Nebraska adopted new legislation that in part requires local Natural Resources Districts to include the effect of groundwater use on surface-water systems in their groundwater management plan. In response the U.S. Geological Survey, in cooperation with the Upper Elkhorn, Lower Elkhorn, Upper Loup, Lower Loup, Middle Niobrara, Lower Niobrara, Lewis and Clark, and Lower Platte North Natural Resources Districts, did a study during 2006-07 to investigate the surface-water and groundwater interaction within a 79,800-square-kilometer area in north-central Nebraska. To determine how streambed materials affect surface-water and groundwater interaction, surface geophysical and lithologic data were integrated at four sites to characterize the hydrogeologic conditions within the study area. Frequency-domain electromagnetic and waterborne direct- current resistivity profiles were collected to map the near-surface hydrogeologic conditions along sections of Ainsworth Canal near Ainsworth, Nebraska; Mirdan and Geranium Canals near Ord, Nebraska; North Loup River near Ord, Nebraska; and Middle Loup River near Thedford, Nebraska. Lithologic data were collected from test holes at each site to aid interpretation of the geophysical data. Geostatistical analysis incorporating the spatial variability of resistivity was used to account for the effect of lithologic heterogeneity on effective hydraulic permeability. The geostatistical analysis and lithologic data descriptions were used to make an interpretation of the hydrogeologic system and derive estimates of surface-water/groundwater interaction potential within the canals and streambeds. The estimated interaction potential at the Ainsworth Canal site and the Mirdan and Geranium Canal site is generally low to moderately low. The sediment textures at nearby test holes typically were silt and clay and fine-to-medium sand. The apparent resistivity values for these sites ranged from 2 to 120 ohm-meters. The vertical

  20. Nuclear-structure studies of exotic nuclei with MINIBALL

    Science.gov (United States)

    Butler, P. A.; Cederkall, J.; Reiter, P.

    2017-04-01

    High-resolution γ-ray spectroscopy has been established at ISOLDE for nuclear-structure and nuclear-reaction studies with reaccelerated radioactive ion beams provided by the REX-ISOLDE facility. The MINIBALL spectrometer comprises 24 six-fold segmented, encapsulated high-purity germanium crystals. It was specially designed for highest γ-ray detection efficiency which is advantageous for low-intensity radioactive ion beams. The MINIBALL array has been used in numerous Coulomb-excitation and transfer-reaction experiments with exotic ion beams of energies up to 3 MeV A–1. The physics case covers a wide range of topics which are addressed with beams ranging from neutron-rich magnesium isotopes up to heavy radium isotopes. In the future the HIE-ISOLDE will allow the in-beam γ-ray spectroscopy program to proceed with higher secondary-beam intensity, higher beam energy and better beam quality.

  1. A Semi-Classical Model to Study Nuclear Fragmentation

    Science.gov (United States)

    Navarro, Martha; Chernomoretz, Ariel; Dorso, Claudio; Lopez, Jorge

    1999-10-01

    A semi-classical model based on the use of molecular dynamics has been developed for the study of heavy-ion reactions at intermediate energies. The model reproduces nucleon-nucleon cross sections through the use of a two-body potential. The study covers several characteristics of heavy-ion collisions, such as formation of necks, and formation of intermediate residue. Preliminary results on the use of the model to study the caloric curve of nuclear matter and the temperature evolution of the system are also discussed.

  2. Efeito da nifedipina gel 0,2% nas pressões de canal anal e na dor pós-operatória: estudo após hemorroidectomia pela técnica aberta Effect of 0.2% nifedipine gel on anal canal pressures and postoperative pain: study following hemorrhoidectomy by open technique

    Directory of Open Access Journals (Sweden)

    Maria Auxiliadora Prolungatti Cesar

    2007-12-01

    Full Text Available INTRODUÇÃO: As hemorróidas são muito freqüentes e após o seu tratamento cirúrgico tem se observado que a dor causa muito sofrimento. Várias alternativas tem sido estudadas para melhorar a dor pós-operatória dentre elas a esfincterotomia cirúrgica que pode em alguns casos causar algum grau de incontinência fecal. Por esse motivo vários estudos tem utilizado a esfincterotomia química com nifedipina, diltiazen, trinitrato de glicerina e toxina botulínica. O objetivo dessa pesquisa foi avaliar o efeito da nifedipina tópica nas diminuições das pressões do canal anal e consequente influência na melhora da dor pós-operatória. MATERIAL E MÉTODO: Utilização da nifedipina tópica gel 0,2% (Grupo 1 e lidocaina 2% (Grupo 2 no pós operatório de hemorroidectomia aferindo as pressões no pré, primeiro, quarto e sétimo dias de pós operatório, associado de medida de dor todos os dias do pós-operatório através de tabela analógica. RESULTADOS: Os autores não encontraram diferenças em relação às pressões de canal anal mas em relação à dor referida estas foram em menor intensidade no grupo que recebeu a nifedipina. CONCLUSÕES: a nifedipina gel foi eficiente na analgesia pós-operatória, no entanto não alterou as pressões do canal anal.INTRODUCTION: Hemorrhoids are very common and pain following their surgical treatment causes great suffering. Various alternatives have been studied for reducing postoperative pain. Among these is surgical sphincterotomy, which may in some cases cause some degree of fecal incontinence. For this reason, several studies have used chemical sphincterotomy, with nifedipine, diltiazem, glycerin trinitrate or botulinum toxin. The objective of the present study was to investigate the effects of topical nifedipine for reducing anal canal pressures and consequently reducing postoperative pain. MATERIAL AND METHOD: Topical gels of 0.2% nifedipine plus 2% lidocaine (Group 1 and 2% lidocaine alone

  3. Analysis of root canal anatomy morphological study of maxillary second molars%上颌第二磨牙根管解剖形态的分析

    Institute of Scientific and Technical Information of China (English)

    彭林红

    2011-01-01

    Objective To observe the root canal anatomy morphology of the maxillary second molars. Methods Collected 86 maxillary second molars. Observed their root canal orifices distribution under naked eye and magnifying glass,then take account of the numbers of rootcanal orifices. Observed the location of apical foramens under the naked eye. Results Totally 9. 3% of maxillary second molars had two root canals under naked eye and magnifying glass. 84. 9% and 74. 4% had three root canals ,5. 8% and 16. 3% had four root canals under naked eye or magnifying glass. 76. 7% of the main apical foramens were located at lateral. Conclusions The orientation of root canal orifices could be improved by use of equipments. Knowing about root canal anatomy morphological could be useful in root canal therapy.%目的 观察上颌第二磨牙根管的解剖形态及其变异情况.方法 收集86个上颌第二磨牙,肉眼及放大镜下观察其根管口的数目,不锈钢K锉扩锉根管至根尖孔,肉眼下观察其根尖孔开口位置并测量其牙根和根管长度.结果 肉眼下及放大镜下检出上颌第二磨牙双根管口者均为9.3%;肉眼下及放大镜下检出上颌第二磨牙三根管口者分别为84.9%和74.4%(P<0.05),检出四根管口者分别为5.8%和16.3%(P<0.05),76.7%的根尖孔为侧方开口,根管长度小于牙根长度.结论 在放大视野下,可提高上颌第二磨牙的根管口检出率,了解上颌第二磨牙根管解剖形态,可提高根管治疗的成功率.

  4. 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...

  5. Analytical study of nozzle performance for nuclear thermal rockets

    Science.gov (United States)

    Davidian, Kenneth O.; Kacynski, Kenneth J.

    1991-01-01

    Nuclear propulsion has been identified as one of the key technologies needed for human exploration of the Moon and Mars. The Nuclear Thermal Rocket (NTR) uses a nuclear reactor to heat hydrogen to a high temperature followed by expansion through a conventional convergent-divergent nozzle. A parametric study of NTR nozzles was performed using the Rocket Engine Design Expert System (REDES) at the NASA Lewis Research Center. The REDES used the JANNAF standard rigorous methodology to determine nozzle performance over a range of chamber temperatures, chamber pressures, thrust levels, and different nozzle configurations. A design condition was set by fixing the propulsion system exit radius at five meters and throat radius was varied to achieve a target thrust level. An adiabatic wall was assumed for the nozzle, and its length was assumed to be 80 percent of a 15 degree cone. The results conclude that although the performance of the NTR, based on infinite reaction rates, looks promising at low chamber pressures, finite rate chemical reactions will cause the actual performance to be considerably lower. Parameters which have a major influence on the delivered specific impulse value include the chamber temperature and the chamber pressures in the high thrust domain. Other parameters, such as 2-D and boundary layer effects, kinetic rates, and number of nozzles, affect the deliverable performance of an NTR nozzle to a lesser degree. For a single nozzle, maximum performance of 930 seconds and 1030 seconds occur at chamber temperatures of 2700 and 3100 K, respectively.

  6. Depolarization canals and interstellar turbulence

    CERN Document Server

    Fletcher, A; Fletcher, Andrew; Shukurov, Anvar

    2006-01-01

    Recent radio polarization observations have revealed a plethora of unexpected features in the polarized Galactic radio background that arise from propagation effects in the random (turbulent) interstellar medium. The canals are especially striking among them, a random network of very dark, narrow regions clearly visible in many directions against a bright polarized Galactic synchrotron background. There are no obvious physical structures in the ISM that may have caused the canals, and so they have been called Faraday ghosts. They evidently carry information about interstellar turbulence but only now is it becoming clear how this information can be extracted. Two theories for the origin of the canals have been proposed; both attribute the canals to Faraday rotation, but one invokes strong gradients in Faraday rotation in the sky plane (specifically, in a foreground Faraday screen) and the other only relies on line-of-sight effects (differential Faraday rotation). In this review we discuss the physical nature o...

  7. Clinical study on root canal preparation immediately after root canal treatment%根管治疗术后即刻桩核预备并冠修复的临床观察

    Institute of Scientific and Technical Information of China (English)

    田鸿旭; 王毅

    2015-01-01

    Objective To observe the effects of root canal preparation for post-core immediately after root canal obtu-ration. Methods A total of 106 cases of mutilated coronal tooth structure, after endodontic therapy, indicated for post-core and crown, collected from dental outpatients in our hospital during 1st Oct 2011-30th Sep 2013, were randomly divided into the control group and the experimental group. The experimental group were prepared for post space 7 days after root obturation, and then the teeth were prepared for retention of crowns; while in control group, post space was made 7 days after obturation. The two groups were observed in intervals of every half a year after treatment to examine the integrity, masticatory function and retention. Meteyards were established to evaluate its clinical effects. Results During follow-up visiting patients half a year to 2 years, in control group, there was 1 patient with splitting along buc-clingual direction and 4 patients with fracture of coronal structure before preparation;after restoration there were 3 pa-tients with periodontitis in the 1st year, 4 patients with periodical periodontitis, and 1 patient with loosening of post in the 2nd year, all of which were failure cases. In experimental group, before preparation there were no fracture case;after restoration there were 2 patients with periodical periodontitis in the 2nd year and 1 patient with periodontitis in 1 year. All the 3 cases counted as failure cases. The total successful rate in control group was 76.36%, and 94.12% in experimental group. The successful rate in the experimental group was significantly higher than the control group(P<0.05). Conclusion Root canal preparation for post-core immediately after obturation is more successful than the usual way with better apical sealing,less complication and frequency of teeth fracture .%目的 观察根管充填术后即刻进行桩核预备的临床疗效. 方法 选取我院2011年10月1日~2013年9月30日门诊93

  8. Horizontal Canal Benign Positional Vertigo

    Directory of Open Access Journals (Sweden)

    Mohtaram Najafi

    1998-03-01

    Full Text Available Benign paroxysmal positional vertigo (BPPV is a syndrome characterized by transient episodes of vertigo in association with rapid changes in head position in Dix-Halpike Maneuver. This kind of vertigo is thought to be caused by migration of otoconial debris into canals other than the posterior canal, such as the anterior or lateral canals. It is also theoretically possible for many aberrant patterns of BPPV to occur from an interaction of debris in several canals, location of debris within the canal, and central adaptation patterns to lesions. The symptoms of BPPV are much more consistent with free-moving densities (canaliths in the posterior SCC rather than fixed densities attached to the cupula. While the head is upright, the particles sit in the PSC at the most gravity-dependent position. The best method to induce and see vertigo and nystagmus in BPPV of the lateral semicircular canal is to rotate head 90°while patient is in the supine position, nystagmus would appear in the unaffected side weaker but longer than the affected side. canal paresis has been described in one third of the patients with BPPV. Adaptation which is one of the remarkable features of BPPV in PSC is rarely seen in LSC. Rotations of 270° or 360° around the yaw axis (the so-called barbecue maneuver toward the unaffected ear are popular methods for the treatment of geotropic HC-BPPV. These maneuvers consist of sequential head turning of 90° toward the healthy side while supine. With these maneuvers, the free-floating otoconial debris migrates in the ampullofugal direction, finally entering the utricle through the nonampullated end of the horizontal canal. This kind of vertigo recovers spontaneously more rapidly and suddenly.

  9. 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.

  10. Radio-anatomical Study of the Greater Palatine Canal and the Pterygopalatine Fossa in a Lebanese Population: A Consideration for Maxillary Nerve Block

    Directory of Open Access Journals (Sweden)

    Georges Aoun

    2016-01-01

    Full Text Available Aim: The aim of this study was to describe the morphology of the component, greater palatine canal-pterygopalatine fossa (GPC-PPF, in a Lebanese population using cone-beam computed tomography (CBCT technology. Materials and Methods: CBCT images of 79 Lebanese adult patients (38 females and 41 males were included in this study, and a total of 158 cases were evaluated bilaterally. The length and path of the GPCs-PPFs were determined, and the data obtained analyzed statistically. Results: In the sagittal plane, of all the GPCs-PPFs assessed, the average length was 35.02 mm on the right and 35.01 mm on the left. The most common anatomic path consisted in the presence of a curvature resulting in an internal narrowing whose average diameter was 2.4 mm on the right and 2.45 mm on the left. The mean diameter of the upper opening was 5.85 mm on the right and 5.82 mm on the left. As for the lower opening corresponding to the greater palatine foramen, the right and left average diameters were 6.39 mm and 6.42 mm, respectively. Conclusion: Within the limits of this study, we concluded that throughout the Lebanese population, the GPC-PPF path is variable with a predominance of curved one (77.21% [122/158] in both the right and left sides; however, the GPC-PPF length does not significantly vary according to gender and side.

  11. Nuclear forensics of special nuclear material at Los Alamos: three recent studies

    Energy Technology Data Exchange (ETDEWEB)

    Tandon, Lav [Los Alamos National Laboratory; Gallimore, David L [Los Alamos National Laboratory; Garduon, Katherine [Los Alamos National Laboratory; Keller, Russell C [Los Alamos National Laboratory; Kuhn, Kevin J [Los Alamos National Laboratory; Lujan, Elmer J [Los Alamos National Laboratory; Martinez, Alexander [Los Alamos National Laboratory; Myers, Steven C [Los Alamos National Laboratory; Moore, Steve S [Los Alamos National Laboratory; Porterfield, Donivan R [Los Alamos National Laboratory; Schwartz, Daniel S [Los Alamos National Laboratory; Spencer, Khalil J [Los Alamos National Laboratory; Townsend, Lisa E [Los Alamos National Laboratory; Xu, Ning [Los Alamos National Laboratory

    2010-01-01

    Nuclear forensics of special nuclear materials is a highly specialized field because there are few analytical laboratories in the world that can safely handle nuclear materials, perform high accuracy and precision analysis using validated analytical methods. The goal of nuclear forensics is to establish an unambiguous link between illicitly trafficked nuclear material and its origin. The Los Alamos National Laboratory Nuclear Materials Signatures Program has implemented a graded 'conduct of operations' type approach for determining the unique nuclear, chemical, and physical signatures needed to identify the manufacturing process, intended use, and origin of interdicted nuclear material. In our approach an analysis flow path was developed for determining key signatures necessary for attributing unknown materials to a source. This analysis flow path included both destructive (i.e., alpha spectrometry, ICP-MS, ICP-AES, TIMS, particle size distribution, density and particle fractionation) and non-destructive (i.e., gamma-ray spectrometry, optical microscopy, SEM, XRD, and x-ray fluorescence) characterization techniques. Analytical techniques and results from three recent cases characterized by this analysis flow path along with an evaluation of the usefulness of this approach will be discussed in this paper.

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

    OpenAIRE

    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 faecali...

  13. Lesions in the external auditory canal

    Directory of Open Access Journals (Sweden)

    Priyank S Chatra

    2011-01-01

    Full Text Available The external auditory canal is an S- shaped osseo-cartilaginous structure that extends from the auricle to the tympanic membrane. Congenital, inflammatory, neoplastic, and traumatic lesions can affect the EAC. High-resolution CT is well suited for the evaluation of the temporal bone, which has a complex anatomy with multiple small structures. In this study, we describe the various lesions affecting the EAC.

  14. Carotid canal dehiscence in the human skull

    Energy Technology Data Exchange (ETDEWEB)

    Pastor Vazquez, J.F.; Gil Verona, J.A. [Department of Anatomy, Faculty of Medicine, University of Valladolid, Ramon y Cajal, 7, E-47005 Valladolid (Spain); Garcia Porrero, M. [Department of Radiology, Faculty of Medicine, University of Valladolid (Spain)

    1999-06-01

    Abnormalities of the floor of the carotid canal have been studied in 538 skulls. These abnormalities range from a fissure to total absence of the floor. This variation may be caused by abnormalities of the internal carotid artery or deficiencies in ossification of the skull base. CT suggests that these changes should be taken into account by surgeons working on the skull base. (orig.) With 4 figs., 8 refs.

  15. 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.

  16. Occurrence and abundance of antibiotics and resistance genes in rivers, canal and near drug formulation facilities--a study in Pakistan.

    Directory of Open Access Journals (Sweden)

    Ghazanfar Ali Khan

    Full Text Available Antibiotic resistance (AR is a global phenomenon that has severe epidemiological ramifications world-wide. It has been suggested that antibiotics that have been discharged into the natural aquatic environments after usage or manufacture can promote the occurrence of antibiotic resistance genes (ARG. These environmental ARGs could serve as a reservoir and be horizontally transferred to human-associated bacteria and thus contribute to AR proliferation. The aim of this study was to investigate the anthropogenic load of antibiotics in Northern Pakistan and study the occurrence of ARGs in selected samples from this region. 19 sampling sites were selected; including six rivers, one dam, one canal, one sewage drain and four drug formulation facilities. Our results show that five of the rivers have antibiotic levels comparable to surface water measurements in unpolluted sites in Europe and the US. However, high levels of antibiotics could be detected in the downstream river in close vicinity of the 10 million city Lahore, 1100, 1700 and 2700 ng L(-1 for oxytetracycline, trimethoprim, and sulfamethoxazole respectively. Highest detected levels were at one of the drug formulation facilities, with the measured levels of 1100, 4100, 6200, 7300, 8000, 27,000, 28,000 and 49,000 ng L(-1 of erythromycin, lincomycin, ciprofloxacin, ofloxacin, levofloxacin, oxytetracycline, trimethoprim and sulfamethoxazole respectively. ARGs were also detected at the sites and the highest levels of ARGs detected, sulI and dfrA1, were directly associated with the antibiotics detected at the highest concentrations, sulfamethoxazole and trimethoprim. Highest levels of both antibiotics and ARGs were seen at a drug formulation facility, within an industrial estate with a low number of local residents and no hospitals in the vicinity, which indicates that the levels of ARGs at this site were associated with the environmental levels of antibiotics.

  17. 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.

  18. 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 determine...... theED95. Distal filling of the adductor canal was assessed by magnetic resonance imaging (primary outcome). Secondary outcomeswere the effect of volume on proximal spread to the femoral triangle (also assessed by magnetic resonance imaging), quadricepsmuscle weakness (decrease by ≥25% from baseline...

  19. Special nuclear material detection studies with the SMANDRA mobile system

    Science.gov (United States)

    Cester, D.; Nebbia, G.; Stevanato, L.; Viesti, G.; Neri, F.; Petrucci, S.; Selmi, S.; Tintori, C.; Peerani, P.; Tomanin, A.

    2012-02-01

    The detection of special nuclear material has been studied with the SMANDRA mobile inspection system used both as a high sensitivity passive neutron/gamma spectroscopic tool and as an active inspection device using tagged neutrons. The detection of plutonium samples is possible with passive interrogation, the passive detection of uranium being much more difficult because of the low neutron yield and of the easiness of shielding the gamma rays. However, we show that active interrogation with tagged neutrons is able to provide signatures for the discrimination of uranium against other materials.

  20. Tokamak Transmutation of (nuclear) Waste (TTW): Parametric studies

    Science.gov (United States)

    Cheng, E. T.; Krakowski, R. A.; Peng, Y. K. M.

    Radioactive waste generated as part of the commercial-power and defense nuclear programs can be either stored or transmuted. The latter treatment requires a capital-intensive neutron source and is reserved for particularly hazardous and long-lived actinide and fission-product waste. A comparative description of fusion-based transmutation is made on the basis of rudimentary estimates of ergonic performance and transmutation capacities versus inventories for both ultra-low aspect-ratio (spherical torus, ST) and conversional (aspect-ratio) tokamak fusion-power-core drivers. The parametric systems studies reported herein provides a preamble to more-detailed, cost-based systems analyses.

  1. 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.

  2. An application study on effect of three different impression materials on taking impression of root canals%三种印模材料在根管取模中的比较研究

    Institute of Scientific and Technical Information of China (English)

    肖云鹤; 刘洋; 余美芳; 熊贵忠; 王行

    2016-01-01

    Objective:The purpose of this study is to evaluate the effect of three different impression materials on taking impression of root canals of extracted teeth by observing the microleakage degree of post core. Method:Extracted bicuspids were chosen and divided into three groups after root canal therapy. In each group,root canal impressions were made by hydrocolloid,silicone rubber and polyether respectively to generate post cores. The microleakages were observed af-ter the restoration of post cores. Result:The microleakages of silicone rubber and polyether were less than hydrocolloid,The differences between the two groups were statistically significant (P0.05). Conclusion:The silicone rubber and polyether are all suitable for use as root-canal impression materials.%目的:采用3种印模材料对离体牙根管进行取模,对比观察桩核微渗漏情况。方法:离体前磨牙根管治疗后桩道预备,分别用琼脂、硅橡胶、聚醚橡胶进行根管取模,桩核修复后观测微渗漏情况。结果:硅橡胶组和聚醚橡胶组微渗漏小于琼脂组,组间比较差异有统计学意义(P0.05)。结论:硅橡胶和聚醚橡胶是很好的根管取模印模材。

  3. Study of nuclear clustering using the modern shell model approach

    Science.gov (United States)

    Volya, Alexander; Tchuvil'Sky, Yury

    2014-03-01

    Nuclear clustering, alpha decays, and multi-particle correlations are important components of nuclear dynamics. In this work we use the modern configuration-interaction approach with most advanced realistic shell-model Hamiltonians to study these questions. We utilize the algebraic many-nucleon structures and the corresponding fractional parentage coefficients to build the translationally invariant wave functions of the alpha-cluster channels. We explore the alpha spectroscopic factors, study the distribution of clustering strength, and discuss the structure of an effective 4-body operator describing the in-medium alpha dynamics in the multi-shell valence configuration space. Sensitivity of alpha clustering to the components of an effective Hamiltonian, which includes its collective and many-body components, as well as isospin symmetry breaking terms, are of interest. We offer effective techniques for evaluation of the cluster spectroscopic factors satisfying the orthogonality conditions of the respective cluster channels. We present a study of clustering phenomena, single-particle dynamics, and electromagnetic transitions for a number of nuclei in p-sd shells and compare our results with the experimentally available data. This work is supported by the U.S. Department of Energy under contract number DE-SC0009883.

  4. The efficacy of the Self-Adjusting File versus WaveOne in removal of root filling residue that remains in oval canals after the use of ProTaper retreatment files: A cone-beam computed tomography study

    Directory of Open Access Journals (Sweden)

    Ajinkya M Pawar

    2016-01-01

    Full Text Available Aim: The current ex vivo study compared the efficacy of removing root fillings using ProTaper retreatment files followed by either WaveOne reciprocating file or the Self-Adjusting File (SAF. Materials and Methods: Forty maxillary canines with single oval root canal were selected and sectioned to obtain 18-mm root segments. The root canals were instrumented with WaveOne primary files, followed by obturation using warm lateral compaction, and the sealer was allowed to fully set. The teeth were then divided into two equal groups (N = 20. Initial removal of the bulk of root filling material was performed with ProTaper retreatment files, followed by either WaveOne files (Group 1 or SAF (Group 2. Endosolv R was used as a gutta-percha softener. Preoperative and postoperative high-resolution cone-beam computed tomography (CBCT was used to measure the volume of the root filling residue that was left after the procedure. Statistical analysis was performed using t-test. Results: The mean volume of root filling residue in Group 1 was 9.4 (±0.5 mm 3 , whereas in Group 2 the residue volume was 2.6 (±0.4 mm 3 , (P < 0.001; t-test. Conclusions: When SAF was used after ProTaper retreatment files, significantly less root filling residue was left in the canals compared to when WaveOne was used.

  5. Study of Nuclear Effects in the Computation of the 0{\

    CERN Document Server

    Neacsu, Andrei

    2013-01-01

    We analyse the effects that different nuclear structure approximations associated with the short range correlations (SRC), finite nucleon size (FNS), higher order terms in the nucleon currents (HOC) and with some nuclear input parameters, have on the values of the nuclear matrix elements (NMEs) for the neutrinoless double beta (0{\

  6. Limitations of navigation through Nubaria canal, Egypt.

    Science.gov (United States)

    Samuel, Magdy G

    2014-03-01

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

  7. Limitations of navigation through Nubaria canal, Egypt

    Directory of Open Access Journals (Sweden)

    Magdy G. Samuel

    2014-03-01

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

  8. Delineating ground water recharge from leaking irrigation canals using water chemistry and isotopes.

    Science.gov (United States)

    Harvey, F E; Sibray, S S

    2001-01-01

    Across the Great Plains irrigation canals are used to transport water to cropland. Many of these canals are unlined, and leakage from them has been the focus of an ongoing legal, economic, and philosophical debate as to whether this lost water should be considered waste or be viewed as a beneficial and reasonable use since it contributes to regional ground water recharge. While historically there has been much speculation about the impact of canal leakage on local ground water, actual data are scarce. This study was launched to investigate the impact of leakage from the Interstate Canal, in the western panhandle of Nebraska, on the hydrology and water quality of the local aquifer using water chemistry and environmental isotopes. Numerous monitoring wells were installed in and around a small wetland area adjacent to the canal, and ground water levels were monitored from June 1992 until January 1995. Using the water level data, the seepage loss from the canal was estimated. In addition, the canal, the monitoring wells, and several nearby stock and irrigation wells were sampled for inorganic and environmental isotope analysis to assess water quality changes, and to determine the extent of recharge resulting from canal leakage. The results of water level monitoring within study wells indicates a rise in local ground water levels occurs seasonally as a result of leakage during periods when the canal is filled. This rise redirects local ground water flow and provides water to nearby wetland ecosystems during the summer months. Chemical and isotopic results were used to delineate canal, surface, and ground water and indicate that leaking canal water recharges both the surface alluvial aquifer and upper portions of the underlying Brule Aquifer. The results of this study indicate that lining the Interstate Canal could lower ground water levels adjacent to the canal, and could adversely impact the local aquifer.

  9. Dimensions of the spinal canal in individuals symptomatic and non-symptomatic for sciatica: A CT study

    Energy Technology Data Exchange (ETDEWEB)

    Wilmink, J.T.; Korte, J.H.; Penning, L.

    1988-12-01

    Measurements obtained in 50 spinal CT studies of patients referred for suspected lumbosacral nerve root compression, were compared to those of a group of 30 individuals asymptomatic in this respect, who had been referred for abdominal pathology. Transverse ligamentous interfacet and transverse dural dimensions were significantly reduced in the sciatica group, with usually normal interpedicular and sagittal dimensions ruling out idiopathic developmental stenosis. The borderline value for ligamentous interfacet distance (ILD) at L4-5 appeared to be 11 mm.

  10. Numerical study of the structure of thermal plume in a vertical channel: Effect of the height of canal

    Directory of Open Access Journals (Sweden)

    Jouini Belgacem

    2016-01-01

    Full Text Available In this paper we propose to study numerically, by means of a software Named Calculation FDS, a thermal plume evolve from a source at the entrance to of a vertical channel. In the literature, there are researchers who interested in the interaction of plume with his the confinement medium. These studies are based on the determination of the global structure of plume confined. They found that this plume consists of three distinct zones. A first zone near source (instability zone followed by a second zone, such as the development of plume, and a third zone which is the zone of turbulence, Comparing the overall structure of the plume confined to that of the free plume, we can identify the presence of a third zone (zone of instability. The aim is firstly to determine the height of the instability zone located above of source, and secondly, to make a spectral study frequencies exhaust. Thus, effects of the geometrical parameters on frequencies of these escapements and the height an instability zone. The final aim is to establish correlations between the dimensionless numbers of Strouhal and Grashof.

  11. A study on the establishment of national nuclear foreign policy

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Keun Bae; Ham, Chul Hoon; Lee, Kwang Suk; Cho, Il Hoon; Lee, Byung Wook; Lee, Jae Sung; Lee, Byung Woon; Choi, Yung Lok; Koh, Han Suk [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1994-12-01

    This study is composed mainly of the current status of international non-proliferation, the NPT extension, IAEA Status, the circumstances of nuclear export control system, and the Vienna convention and London convention. The recent circumstances of the NPT have been analyzed. We established counter measures and strategies on the NPT extension conference. After reviewing the international export control system of NSG members, we suggested the factors which should be involved in the nuclear export control system. Also, U.S. systems on retransferring were intensively reviewed. In connection with the challenges coped with by the IAEA, several agenda have been reviewed and analyzed: the financing status of the Agency; the program 93+2 for the strengthening of effectiveness and improving of efficiency in the safeguards system. In connection with the amendment work of the Vienna Convention, we studied the major contents of four proposals which were suggested. In the case of the London Convention, the causes of maritime pollution and the kinds of sea dumping material were investigated. 3 figs, 13 tabs, 66 refs. (Author).

  12. The Epidemiological Study on Cervical Spinal Canal Ratio of Xinjiang Uighur%新疆维吾尔族人正常颈椎管率的流行病学研究

    Institute of Scientific and Technical Information of China (English)

    张鹰; 杨宇; 凯赛尔江·艾合买提; 徐子昂; 倪鹏辉

    2016-01-01

    目的:研究新疆维吾尔族正常颈椎管率的流行病学特点。方法应用随机、整群、分层抽样法,抽取新疆5个市(喀什、和田、吐鲁番、哈密、伊宁)健康成年人群脊柱样本,收集维吾尔民族不同性别、不同年龄组人群的正常颈椎侧位 X 线片,测量并统计颈椎 C2~7各节段椎管矢状径(a)及与其对应的椎体矢状径(b),并换算成颈椎管率(a/ b)。结果新疆维吾尔族的平均颈椎 C2~7节段(除 C4稍低于 C5节段外)椎管率呈现从高到低的趋势;不同性别间的椎管率在颈椎C2~7节段男性明显小于女性( P ﹤0.05),不同性别间的椎体矢状径在颈椎C2~7节段男性大于女性( P ﹤0.05),不同性别间的椎管矢状径在颈椎 C2~7节段女性与男性接近,差异无统计学意义(P ﹥0.05)。维吾尔族不同年龄组的颈椎管率在 C2、C3、C4、C6、C7节段的差异有统计学意义(P ﹤0.05),但不同年龄组颈椎管率在颈椎 C5节段的差异无统计学意义(P ﹥0.05),不同年龄组的椎管及椎体矢状径在颈椎 C2~7节段女性与男性接近,差异均无统计学意义(P ﹥0.05)。结论颈椎管率的相关测量结果揭示了新疆维吾尔族正常颈椎管率的流行病学特点,为临床应用及进一步基因学研究新疆维吾尔族颈椎管率的解剖学和遗传学的特点提供统计学依据。%Objective To study the epidemiological characteristics of the rate of cervical spinal canal of Xinjiang uygur. Methods We selected five cities(kashi,hotan,turpan,hami,yining)of Xinjiang and examed the adults of healthy spine as samples by random layer sampling method. Lateral X-ray of cervical vertebral of different genders groups and different age groups of Xinjiang uygur were collected. We measured sagittal diameter of vertebral canal(a)and the sagittal diameter of ver-tebral body(b)of each of cervical vertebra C2 ~ 7 and converted to

  13. Assessment of trace metal contamination in a historical freshwater canal (Buckingham Canal), Chennai, India.

    Science.gov (United States)

    Jayaprakash, M; Nagarajan, R; Velmurugan, P M; Sathiyamoorthy, J; Krishnamurthy, R R; Urban, B

    2012-12-01

    The present study was done to assess the sources and the major processes controlling the trace metal distribution in sediments of Buckingham Canal. Based on the observed geochemical variations, the sediments are grouped as South Buckingham Canal and North Buckingham Canal sediments (SBC and NBC, respectively). SBC sediments show enrichment in Fe, Ti, Mn, Cr, V, Mo, and As concentrations, while NBC sediments show enrichment in Sn, Cu, Pb, Zn, Ni, and Hg. The calculated Chemical Index of Alteration and Chemical Index of Weathering values for all the sediments are relatively higher than the North American Shale Composite and Upper Continental Crust but similar to Post-Archaean Average Shale, and suggest a source area with moderate weathering. Overall, SBC sediments are highly enriched in Mo, Zn, Cu, and Hg (geoaccumulation index (I(geo)) class 4-6), whereas NBC sediments are enriched in Sn, Cu, Zn, and Hg (I(geo) class 4-6). Cu, Ni, and Cr show higher than Effects-Range Median values and hence the biological adverse effect of these metals is 20%; Zn, which accounts for 50%, in the NBC sediments, has a more biological adverse effect than other metals found in these sediments. The calculated I(geo), Enrichment Factor, and Contamination Factor values indicate that Mo, Hg, Sn, Cu, and Zn are highly enriched in the Buckingham Canal sediments, suggesting the rapid urban and industrial development of Chennai Metropolitan City have negatively influenced on the surrounding aquatic ecosystem.

  14. World nuclear performance report 2016. A new study by World Nuclear Association

    Energy Technology Data Exchange (ETDEWEB)

    Cobb, Jonathan [World Nuclear Association, London (United Kingdom)

    2016-08-15

    A larger number of nuclear power units are under construction than at any other time in the last 25 years, and with another ten new reactors coming online 2015 demonstrated improving new build performance all round. The existing global fleet, totally 439 by year-end, generated roughly 10 % of the world's electricity, making up around one-third of the world's low-carbon electricity supply. Nevertheless, there are challenges ahead for the global nuclear industry. The World Nuclear Association's vision for the future global electricity system consists of a diverse mix of low-carbon technologies - where renewables, nuclear and a fossil fuels work together in harmony to ensure a reliable, affordable and clean energy supply.

  15. Study on the establishment of effective nuclear export system

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Byung Koo; So, Dong Sup; Baik, Dae Hyun; Kwack, Eun Ho; Shin, Jang Soo; Yoon, Wan Ki; Park, Wan Soo; Kim, Hyun Tae

    1997-02-01

    To improve Korean nuclear export control system, the modification of the present export license procedure for the nuclear equipment and materials and the classification of control items and their related technologies are required. And it is also necessary to make a database of the original countries who have the right of prior consent. For the efficient export control of LWR items to DPRK, it is desirable to manage the export license scheme of nuclear reactor facility as a total package, and to prepare a control regime for the retransfer of nuclear reactor component such as reactor coolant pump and nuclear fuel whose technologies are not self-reliant. It is especially essential to prepare a systematic procedure for the supply of nuclear equipment and materials to DPRK in order to meet international guidelines of NSG and others through an accord on the nuclear cooperation between Republic of Korea (ROK) and DPRK. The principal elements to be included in the accord are the range of cooperation, the restriction within the peaceful uses, prior consent right in case of retransfer of important nuclear reactor components and of storage, transfer and changes of nuclear fuels, application of safeguards to the supplied Trigger list items, physical protection of nuclear material, requirement of the return of nuclear equipment and materials, and restriction right for the suspension or termination of the agreement. (author). 40 refs., 5 tabs., 8 figs.

  16. 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

  17. A study on future nuclear reactor technology and development strategy

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S. Y.; Kim, S. H.; Sohn, D. S.; Suk, S. D.; Zee, S. K.; Yang, M. H.; Kim, H. J.; Park, W. S

    2000-12-01

    Development of nuclear reactor and fuel cycle technology for future is essential to meet the current issues such as enhancement of nuclear power reactor safety, economically competitive with gas turbine power generation, less production of radioactive waste, proliferation resistant fuel cycle, and public acceptance in consideration of lack of energy resources in the nuclear countries worldwide as well as in Korea. This report deals with as follows, 1) Review the world energy demand and supply perspective and analyse nature of energy and sustainable development to set-up nuclear policy in Korea 2) Recaptitulate the current long term nuclear R and D activities 3) Review nuclear R and D activities and programs of USA, Japan, France, Russia, international organizations such as IAEA, OECD/NEA 4) Recommend development directions of nuclear reactors and fuels.

  18. A study on the development of nuclear policy to respond to international non-proliferation regimes

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byung Wook; Oh, K. B.; Yang, M. H.; Lee, H. M.; Ko, H. S.; Ryu, J. S.; Jung, W. H.; Lim, C. Y

    2006-01-15

    This study analyzed the trends of the nonproliferation regimes in the following three aspects. First, this study analyzed the trends of the international nuclear non-proliferation regime, which includes the NPT, the IAEA safeguards system, the international nuclear export control regime and multilateral nuclear approach. Second, this study forecast the future trends of the nonproliferation systems with the reflection of current international situations. Third, this study also analyzed outstanding issues in nuclear control regimes and derived some factors to reflect national nuclear foreign policy.

  19. 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.

  20. Could spinal canal compression be a cause of polyneuropathy?

    Directory of Open Access Journals (Sweden)

    Richard Bostelmann

    2016-04-01

    Full Text Available Causality between spinal cord compression and polyneuropathy is difficult to define, especially under the circumstances that polyneuropathy can have many causes. Seven patients with spinal cord compression and electrophysiological signs of polyneuropathy were treated surgically on decompression of their spinal canal stenosis in the time from April 2010 to January 2013. Median follow up time was 9 months (2-23 months. Causes of polyneuropathy were: 1 patient with methotrexate-induced polyneuropathy, 1 endocrine-dysfunction-induced, 2 with diabetic- polyneuropathy, and 3 patients had unknown reasons. The localization of the spinal canal stenosis was also varying: 2 patients suffered of cervical spinal canal stenosis and 5 of lumbar. Decompressive surgery led to pain relieve in all patients initially. Surprisingly, also symptoms of polyneuropathy seemed to regress in all 7 patients for the first 5 months after surgery, and in 5 patients for the time of 9 months after surgery. There are two points we would like to emphasize in this short report. Since 5/7 patients with polyneuropathy and spinal canal stenosis improved clinically after surgery, surgery has a place in the treatment of such a combined pathology. Since it seems to be a possible causality between polyneuropathy of unknown origin and spinal cord stenosis, decompression of the spinal canal could also be a therapeutic step in a specific kind of polyneuropathy. Which patients could possibly have a spinal canal stenosis induced polyneuropathy remains a subject of further studies.

  1. 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.

  2. Studying nuclear level densities of {sup 238}U in the nuclear reactions within the macroscopic nuclear models

    Energy Technology Data Exchange (ETDEWEB)

    Razavi, Rohallah; Aghajani, Maghsood; Khooy, Asghar [Imam Hossein Comprehensive Univ., Tehran (Iran, Islamic Republic of). Dept. of Physics; Rahmatinejad, Azam; Taheri, Fariba [Univ. of Zanjan (Iran, Islamic Republic of). Dept. of Physics; Kakavand, Tayeb [Imam Khomeini International Univ., Qazvin (Iran, Islamic Republic of). Dept. of Physics

    2016-05-01

    In this work the nuclear level density parameters of {sup 238}U have been extracted in the back-shifted Fermi gas model (BSFGM), as well as the constant temperature model (CTM), through fitting with the recent experimental data on nuclear level densities measured by the Oslo group. The excitation functions for {sup 238}U(p,2nα){sup 233}Pa, and {sup 238}U(p,4n){sup 235}Np reactions and the fragment yields for the fragments of the {sup 238}U(p,f) reaction have been calculated using obtained level density parameters. The results are compared to their corresponding experimental values. It was found that the extracted excitation functions and the fragment yields in the CTM coincide well with the experimental values in the low-energy region. This finding is according to the claim made by the Oslo group that the extracted level densities of {sup 238}U show a constant temperature behaviour.

  3. Novel nuclear magnetic resonance techniques for studying biological molecules

    Energy Technology Data Exchange (ETDEWEB)

    Laws, David D.

    2000-06-01

    Over the fifty-five year history of Nuclear Magnetic Resonance (NMR), considerable progress has been made in the development of techniques for studying the structure, function, and dynamics of biological molecules. The majority of this research has involved the development of multi-dimensional NMR experiments for studying molecules in solution, although in recent years a number of groups have begun to explore NMR methods for studying biological systems in the solid-state. Despite this new effort, a need still exists for the development of techniques that improve sensitivity, maximize information, and take advantage of all the NMR interactions available in biological molecules. In this dissertation, a variety of novel NMR techniques for studying biomolecules are discussed. A method for determining backbone ({phi}/{psi}) dihedral angles by comparing experimentally determined {sup 13}C{sub a}, chemical-shift anisotropies with theoretical calculations is presented, along with a brief description of the theory behind chemical-shift computation in proteins and peptides. The utility of the Spin-Polarization Induced Nuclear Overhauser Effect (SPINOE) to selectively enhance NMR signals in solution is examined in a variety of systems, as are methods for extracting structural information from cross-relaxation rates that can be measured in SPINOE experiments. Techniques for the production of supercritical and liquid laser-polarized xenon are discussed, as well as the prospects for using optically pumped xenon as a polarizing solvent. In addition, a detailed study of the structure of PrP 89-143 is presented. PrP 89-143 is a 54 residue fragment of the prion proteins which, upon mutation and aggregation, can induce prion diseases in transgenic mice. Whereas the structure of the wild-type PrP 89-143 is a generally unstructured mixture of {alpha}-helical and {beta}-sheet conformers in the solid state, the aggregates formed from the PrP 89-143 mutants appear to be mostly {beta}-sheet.

  4. Exclusive study of nuclear collisions at the AGS

    Energy Technology Data Exchange (ETDEWEB)

    Rai, G.; E895 Collaboration

    1993-08-01

    We propose to carry out a systematic and exclusive measurement of the energy and mass dependence of particle production, correlations and collective effects in Au+Au collisions. We wish to determine the highest compression achievable in nuclear matter and to study its properties. We shall search for evidence for an exotic Equation of State, that is, new physics such as Resonance Matter, Exotica, and QGP. We are also interested in signatures of critical phenomena in dilute nuclear matter. We propose to measure the four-momentum of light mass particles ({pi}{sup {plus_minus}}, K{sub s}{sup 0}, K{sup {plus_minus}}, {Lambda}, n,p,d, {sup 3}He, {sup 4}He, {sup 6}He, and the isotopes of Li and Be), projectile fragments from Z = 6 to Z = 79, and anti-proton production. The majority of the data will be acquired, on an event by event basis, from a state-of-the-art Time Projection Chamber (EOSTPC) built and used at LBL by the EOC collaboration. The TPC provides continuous tracking, almost 4{pi} acceptance and particle identification for the light mass particles.

  5. Nuclear Track Detectors for Environmental Studies and Radiation Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Manzoor, S. [Department of Physics of the University of Bologna and INFN Sezione di Bologna, Viale Berti Pichat 6/2, I-40127 Bologna (Italy); PRD, PINSTECH, P.O. Nilore, Islamabad (Pakistan); COMSATS Institute of Information Technology (CIIT), Islamabad (Pakistan)], E-mail: manzoor@bo.infn.it; Balestra, S.; Cozzi, M.; Errico, M.; Giacomelli, G.; Giorgini, M. [Department of Physics of the University of Bologna and INFN Sezione di Bologna, Viale Berti Pichat 6/2, I-40127 Bologna (Italy); Kumar, A. [Department of Physics of the University of Bologna and INFN Sezione di Bologna, Viale Berti Pichat 6/2, I-40127 Bologna (Italy); Dept. of Physics, Sant Longowal Institute of Eng. and Tech., Longowal 148 106 India (India); Margiotta, A.; Medinaceli, E.; Patrizii, L. [Department of Physics of the University of Bologna and INFN Sezione di Bologna, Viale Berti Pichat 6/2, I-40127 Bologna (Italy); Popa, V. [Department of Physics of the University of Bologna and INFN Sezione di Bologna, Viale Berti Pichat 6/2, I-40127 Bologna (Italy); Institute of Space Sciences, Bucharest R-77125 (Romania); Qureshi, I.E. [PRD, PINSTECH, P.O. Nilore, Islamabad (Pakistan); COMSATS Institute of Information Technology (CIIT), Islamabad (Pakistan); Togo, V. [Department of Physics of the University of Bologna and INFN Sezione di Bologna, Viale Berti Pichat 6/2, I-40127 Bologna (Italy)

    2007-10-15

    Several improvements were made for Nuclear Track Detectors (NTDs) used for environmental studies and for particle searches. A new method was used to determine the bulk etch rate of CR39 and Makrofol NTDs. It is based on the simultaneous measurement of the diameter and of the height of etch-pit cones caused by relativistic heavy ions (158 A GeV Pb{sup 82+} and In{sup 49+} ions) and their fragments. The use of alcohol in the etching solution improves the surface quality of NTDs and it raises their thresholds. The detectors were used for the determination of nuclear fragmentation cross sections of Iron and Silicon ions of 1.0 and 0.41 GeV/nucleon. These measurements are important for the determination of doses in hadrontherapy and for doses received by astronauts. The detectors were also used in the search of massive particles in the cosmic radiation, for the determination of the mass spectrum of cosmic rays and for the evaluation of Po{sup 210}{alpha}-decay and of natural radon concentrations.

  6. Canals - CANALS_HISTORIC_STRUCTURES_IN: Historic Canal Structures in Indiana (Bernardin-Lochmueller & Associates, Point Shapefile)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — Data depicts the locations of historic structures associated with the Wabash-Erie, Central, and Whitewater Canals constructed in Indiana in from 1830-1870. Canal...

  7. Nuclear Magnetic Resonance Study of Nanoscale Ionic Materials

    KAUST Repository

    Oommen, Joanna Mary

    2010-08-13

    Nanoscale ionic materials (NIMs) are a new class of nanomaterials that exhibit interesting properties including negligible vapor pressures and tunable physical states, among others. In this study, we analyzed the temperature-wise performance of NIMs using nuclear magnetic resonance (NMR) spectroscopy. NIMs are relatively stable over a temperature range from 300 to 383 K, rendering them usable in high temperature applications. We confirmed the presence of covalent bonds between the SiO2 core and the sulfonate group and determined relative concentrations of aromatic and aliphatic hydrocarbons. These findings serve as first hand proof-of-concept for the usefulness of NMR analyses in further studies on the diffusive properties of NIMs. © 2010 The Electrochemical Society.

  8. Nuclear structure studies. Progress report, [1988--1994

    Energy Technology Data Exchange (ETDEWEB)

    Walters, W.B.

    1993-07-31

    In this report, newly initiated work at the FMA is described where the use of double-sided strip detectors for charged particle spectroscopy on nuclides near the proton drip line has been investigated. Half lives for proton emitting nuclides have been determined with improved uncertainties. Several sections report on the results of studies of model parameters in the Z = 50 region for even-even nuclides, for odd-mass nuclides and for odd-odd nuclides. Other studies are reported for nuclear orientation in Br and for structure of Pr-147 which lies in a transition zone between reflection-asymmetric, spherical, and prolate nuclides. And there is a section in which the positions of the single Particle levels in the A = 100 region are discussed.

  9. XAFS studies of radiation damage in nuclear materials

    Science.gov (United States)

    Olive, Daniel Thomas

    The growing demand for nuclear energy places a high importance on the development of new materials capable of withstanding higher temperatures and harsher irradiation conditions than those used in existing reactors. By supporting the development of next generation reactors it also becomes possible to close the nuclear fuel cycle, greatly reducing the amount of waste sent for disposal in deep geologic repositories, where its interaction with the environment is also a matter of interest. In this thesis, X-ray absorption fine structure (XAFS) spectroscopy is used to investigate the local atomic structure of systems of interest to nuclear energy. First, two XAFS studies on environmental materials are presented. Granular activated carbon (GAC) was treated with iron to improve its water remediation properties, specifically with respect to arsenic. XAFS was used to determine the nature of iron coating on the GAC surface, and the method of arsenic bonding to the treated surface. Next, a neodymium precipitate from solubility studies carried out for the Waste Isolation Pilot Plant (WIPP) was analyzed. Neodymium was used as an analog for plutonium in brine solutions. XAFS fitting indicated that the neodymium substituted for calcium in a gypsum lattice, providing information useful for future geochemical modeling. XAFS was also used to study radiation damage in materials. A candidate material for advanced reactor structural materials, modified 9Cr--1Mo, was irradiated to 1, 4, and 10 displacements per atom (dpa). XAFS analyses were performed on the Fe, Mo, and Nb K-edges. Irradiation caused a reduction in coordination for all three elements, but the exact behavior was element specific. Damage around Fe atoms was linear with dose, while damage around Mo atoms saturated at or before 1 dpa. XAFS was shown to provide a useful atomic level description of radiation damage for a complex alloy system. Finally, zirconium carbide and zirconium nitride, candidate materials for advanced

  10. 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.

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

    Directory of Open Access Journals (Sweden)

    Lin Zhu

    2014-10-01

    Full Text Available 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.

  12. Study on Enhancing nuclear security cooperation in Northeast Asia

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jounghoon; Heo, Chul [Korea Institute of Nuclear Non-proliferation and Control, Daejeon (Korea, Republic of)

    2015-10-15

    Regional and global cooperation in nuclear security was urged. Nevertheless, it is hard to seek a successful example of regional cooperation in nuclear security, with the exception of EURATOM. Northeast Asia which includes China, Russia, Japan, ROK and, DPRK has many nuclear issues. For example, the concerns of the international community were raised when the DPRK has conducted three nuclear tests. Countries in this region also possess many nuclear power plants and materials. However, there has been no attempt at creating a community or organization for multinational security in this region. In this paper, we discuss various ways of enhancing nuclear security cooperation in Northeast Asia. We begin with an examination of current global, regional and national nuclear security cooperation efforts. We then discuss directions and strategies for nuclear security cooperation in Northeast Asia, and offer some detailed cooperation agendas to be considers. Northeast Asia countries have tried to cooperate in many areas such as energy, environment, economy, and policy. However, nuclear security issues have not been discussed seriously. We need to start cooperating on nuclear security issues, because a nuclear security event may affect several countries. One country may not be able to respond to such an event independently. In order to gain cooperate in nuclear security, we have to be able to suggest pertinent agendas to Northeast Asia countries. R and D, education and training of nuclear security may be a good suggestion for starting cooperation. And more practical and detailed agendas such as joint response and information sharing may be suggested for cooperation strengthening.

  13. Corinth Canal, Greece

    Science.gov (United States)

    2006-01-01

    The Isthmus of Corinth has played a very important role in the history of Greece. It is the only land bridge between the country's north (Attica) and south (Peloponnese). It is a 6 km wide tongue of land separating the Gulf of Corinth from the Saronic Sea. Populations, armies and commodities have got to move through it. In the 6th century BCE, the Greeks built the Diolkos, a 10 meter-wide stone roadway to pull ships across the Isthmus on wooden cylinders and wheeled vehicles. In 1882, a canal was started and completed 11 years later. It is 6343 meters long, 25 meters wide, and 8 meters deep. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet. ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance. The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate. Size: 25.3 by 37.7 kilometers (15.7 by 23.4 miles) Location: 37.9 degrees North latitude, 23 degrees East longitude Orientation: North at top Image

  14. 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.

  15. Fluidmechanics of semicircular canals revisited

    Science.gov (United States)

    Obrist, Dominik

    2008-05-01

    In this work we find the exact solution for the flow field in a semicircular canal which is the main sensor for angular motion in the human body. When the head is rotated the inertia of the fluid in the semicircular canal leads to a deflection of sensory hair cells which are part of a gelatinous structure called cupula. A modal expansion of the governing equation shows that the semicircular organ can be understood as a dynamic system governed by duct modes and a single cupular mode. We use this result to derive an explicit expression for the displacement of the cupula as a function of the angular motion of the head. This result shows in a mathematically and physically clean way that the semicircular canal is a transducer for angular velocity.

  16. 下颌切牙根管解剖显微CT研究%Study of root canal morphology of mandibular incisors by micro-computed tomography in vitro

    Institute of Scientific and Technical Information of China (English)

    朱艳玲; 杨健

    2014-01-01

    Objective:To investigate the anatomy of mandibular incisors using microcomputed tomography(Micro-CT).Methods:62 extracted mandibular incisors were selected from dental clinic and observed by Micro-CT.The anatomy of the teeth was analyzed. Results:83.9% of mandibular incisors had a single canal,72.6% had no accessory canal.The location of the apical foramen varied considerably.The mean distance from the root apex to the major lateral apical foramen was (0.613 ±0.298)mm.Of the canals the bucco-lingual diameter were greater than the mesio-distal diameters and the root bucco-lingual canal tapers were greater than the me-sio-distal.Conclusion:The morphology data of mandibular incisors were obtained using Micro-CT.%目的:采用高分辨率的显微CT观察离体下颌切牙根管解剖结构。方法:收集62颗离体下颌切牙,使用显微CT扫描及三维重建获取每颗牙的解剖数据。结果:83.9%下颌切牙为单根管,72.6%无侧副根管,根尖孔位于旁侧者占56.5%,侧方根尖孔至解剖根尖的距离为(0.613±0.298)mm,下颌切牙根管颊舌向直径及锥度大于近远中向。结论:利用显微CT获得了下颌切牙根管复杂解剖结构的解剖数据。

  17. Surface water quality in a water run-off canal system: A case study in Jubail Industrial City, Kingdom of Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Zia Mahmood Siddiqi

    2016-06-01

    Full Text Available Water quality in a run-off canal system in an industrial area was evaluated for a range of physical and chemical properties comprising trace metals (including mercury (Hg, chromium (Cr, iron (Fe, manganese (Mn, salinity, pH, turbidity, total dissolved solids, total suspended solids, chemical oxygen demand (COD, and dissolved oxygen. High concentrations of potassium (K (1.260–2.345 mg/l and calcium (Ca (19.170–35510 mg/l demonstrated that the salinity in the water was high, which indicates that industrial effluents from fertilizer manufacturing and Chlor-alkali units are being discharged into the canal system. Almost all the metal concentrations in water and sediment were within the thresholds established by the local regulatory body. Concentrations of Cr (0.0154–0.0184 mg/l, Mn (0.0608–0.199 mg/l, Fe (0.023–0.035 mg/l, COD (807–916 mg/l, and turbidity (633 ± 15–783 ± 22 NTU were high where the canal discharges into the Persian Gulf; these discharges may compromise the health of the aquatic ecosystem. There is concern about the levels of Hg in water (0.00135–0.0084 mg/l, suspended sediment (0.00308–0.0096 mg/l, and bed sediment (0.00172–0.00442 mg/l because of the bio-accumulative nature of Hg. We also compared the total Hg concentrations in fish from Jubail, and two nearby cities. Hg contents were highest in fish tissues from Jubail. This is the first time that heavy metal pollution has been assessed in this water run-off canal system; information about Hg is of particular interest and will form the basis of an Hg database for the area that will be useful for future investigations.

  18. 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

  19. ANATOMIC STUDY OF LOCALIZATION OF FORAMEN OVALE, CAROTID CANAL, JUGULAR FORAMEN USING HENLE’S SPINE AS SURFACE LANDMARK IN SOUTH INDIAN ADULT SKULLS

    Directory of Open Access Journals (Sweden)

    Yogitha Ravindranath

    2016-07-01

    Full Text Available BACKGROUND Henle’s Spine (HS is a small bony prominence, anterior to the supramastoid pit, at the postero-superior margin of the external acoustic meatus. Localization of cranial structures using this anatomical landmark is of immense surgical importance to identify and avoid surgical morbidities. AIMS Considering the limited number of research articles describing its anatomy in South Indian skulls, present study was conducted to estimate the location and the difference between the right and left sides of the skull base foramen by using HS as surface landmark, which can act as a guide to various approaches of the skull base surgeries. SETTING AND DESIGN Cross-sectional observational study. MATERIALS AND METHODS Twenty nine (58 sides adult South Indian skulls with prominent HS were studied. Following distances on both right and left sides of the skulls were measured from tip of HS to anterior margin and posterior margin of foramen ovale (HS–AMFO, HS-PMFO; posterolateral and medial jugular foramen (HS-PLJF, HS-PMJF; lateral and medial margin of carotid canal (HS-LMCC, HS-MMCC using digital calliper of 0.01 mm accuracy. STATISTICAL ANALYSIS Data was analysed using SPSS version 16. Mean, Standard deviation was calculated. Side differences were estimated using paired ‘t’ test. RESULTS The mean distance from HS-AMFO was 35.96±2.05 mm, HS-PMFO was 42.57±2.38 mm; HS-PLJF 22.82±2.12 mm, HS-PMJF was 34.08±2.48 mm; HS-LMCC was 26.68±1.95 mm, HS-MMCC was 32.27±2.22 mm. There was a significant difference noted between right and left sides (p<0.05 of Henle’s spine to posterolateral margin of jugular foramen. CONCLUSION Henle’s spine can be used as a reliable landmark to locate the deeper structures of skull base. However, the possibility of side difference among the population should be kept in mind prior to surgery

  20. Bovine Reissner's fiber (RF) and the central canal of the spinal cord: an immunocytochemical study using a set of monoclonal antibodies against the RF-glycoproteins.

    Science.gov (United States)

    Pérez, J; Garrido, O; Cifuentes, M; Alonso, F J; Estivill-Torrús, G; Eller, G; Nualart, F; López-Avalos, M D; Fernández-Llebrez, P; Rodríguez, E M

    1996-10-01

    The subcommissural organ secretes N-linked complex-type glycoproteins into the cerebrospinal fluid. These glycoproteins condense to form Reissner's fiber (RF), which extends along the fourth ventricle and central canal of the spinal cord. A set of three monoclonal antibodies (Mabs 3E6, 3B1, and 2A5) has been obtained using these glycoproteins as immunogens. Competitive and sandwich enzyme-linked immunoassay methods have demonstrated that the three monoclonal antibodies are directed against different epitopes, and that there is no competition among them for their binding to glycoproteins of RF. Mab 3E6 displays immunoblotting properties that are similar to those of a polyclonal antibody against the pool of glycoproteins from RF, but that are different from those of Mabs 3B1 and 2A5. All three antibodies immunostain the bovine subcommissural organ and RF. A population of ependymal cells is stained by the polyclonal antibody, and Mabs 2A5 and 3E6, but not by Mab 3B1. The material present in a population of ependymal cells of the central canal, and the glycoproteins secreted by the subcommissural organ thus probably have partial chemical identity. Some evidence suggests that the immunoreactive ependymal cells are secretory cells. The luminal surface of the central canal is coated by a thin layer of material with immunocytochemical characteristics different from those of the ependymal cells; such a coat may correspond to material released from RF.

  1. Theoretical Studies in Nuclear Physics. [Oregon State Univ. , Corvallis, Oregon

    Energy Technology Data Exchange (ETDEWEB)

    Landau, R.H.; Madsen, V.A.

    1992-01-01

    Work in nuclear structure and reaction theory, specifically, the relation of reactions to the nuclear structure. Other work was in intermediate energy physics, few-body problems, and computational physics that heavy ions can be used to measure simultaneously both neutron and proton multipole matrix elements of the target nucleus has added new interest to this area of nuclear structure. Considerable attention to the is therefore paid to the to the methods for calculating multiple matrix elements.

  2. A Study on Appropriate Measures Against In-and-out Nuclear Environmental Changes

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Young Kyu; Kim, Jae Rok; Hwang, Kyung Ho; Choi, Yoon Seok [KANS, Seoul (Korea, Republic of); Ro, Seung Gi [UMI Co., Seoul (Korea, Republic of); Kim, Shi Hwan [Ulsan University, Ulsan (Korea, Republic of); Nam, Jang Soo [Korean Nuclear Socierty, Daejeon (Korea, Republic of)

    2009-12-15

    To derive appropriate measures against current issues in Korea nuclear community, nuclear senior's forum meetings have been held several times during the study year 2009. Some key issues have been discussed among nuclear seniors including persons in charge of many nuclear organizations, and opinion leaders. Followings are discussed issues and the relevant measures: - To pre-occupy the world market of nuclear power generation following arrangements are essential: diversifying trade commodities, developing export business models, privatising the nuclear industrial organization, simplifying nuclear export window, and putting the retired nuclear scientists to practical use. - To develop future nuclear systems the following arrangements are required: Setting-up detailed milestones, amending the ROK-US nuclear cooperation agreement so as to enable R and D company relations between the two countries, and securing R and D fund as well as a site available for verification of the future nuclear system technology. - To rectify the future nuclear cooperation agreement viable between ROK and US, it would be essential to some basic achievements in pyro-processing technology, and on such a firm ground a strategic cooperation proposal might be effective in line with negotiation between the programmatic prior-consent and the joint determination. - For the effective way of attaining public acceptance, development of creative communication model reflecting the nation's cultural characteristics is required as well as procurement of reliability in communication. These derived policy related measures would be useful for the future nuclear policy development in this country

  3. 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

  4. Specific immunoglobulin measurements related to exposure and resistance to Schistosoma mansoni infection in Sudanese canal cleaners

    DEFF Research Database (Denmark)

    Satti, M.Z.; Lind, Peter; Vennervald, B.J.;

    1996-01-01

    The present work comprises a longitudinal study of Schistosoma mansoni infection in occupationally hyper-exposed canal cleaners in the Sudan and the influence of chemotherapy on humoral immune parameters. The study groups included chronically infected canal cleaners (n = 19), newly recruited canal...... was used to detect specific IgE and IgG subclasses in response to whole worm antigen (WWH) and soluble egg antigen (SEA) before and 3 months after praziquantel treatment in the groups of canal cleaners and before and 1 year after treatment in normally exposed adults. When intensity of infection...

  5. Ablation study of tungsten-based nuclear thermal rocket fuel

    Science.gov (United States)

    Smith, Tabitha Elizabeth Rose

    The research described in this thesis has been performed in order to support the materials research and development efforts of NASA Marshall Space Flight Center (MSFC), of Tungsten-based Nuclear Thermal Rocket (NTR) fuel. The NTR was developed to a point of flight readiness nearly six decades ago and has been undergoing gradual modification and upgrading since then. Due to the simplicity in design of the NTR, and also in the modernization of the materials fabrication processes of nuclear fuel since the 1960's, the fuel of the NTR has been upgraded continuously. Tungsten-based fuel is of great interest to the NTR community, seeking to determine its advantages over the Carbide-based fuel of the previous NTR programs. The materials development and fabrication process contains failure testing, which is currently being conducted at MSFC in the form of heating the material externally and internally to replicate operation within the nuclear reactor of the NTR, such as with hot gas and RF coils. In order to expand on these efforts, experiments and computational studies of Tungsten and a Tungsten Zirconium Oxide sample provided by NASA have been conducted for this dissertation within a plasma arc-jet, meant to induce ablation on the material. Mathematical analysis was also conducted, for purposes of verifying experiments and making predictions. The computational method utilizes Anisimov's kinetic method of plasma ablation, including a thermal conduction parameter from the Chapman Enskog expansion of the Maxwell Boltzmann equations, and has been modified to include a tangential velocity component. Experimental data matches that of the computational data, in which plasma ablation at an angle shows nearly half the ablation of plasma ablation at no angle. Fuel failure analysis of two NASA samples post-testing was conducted, and suggestions have been made for future materials fabrication processes. These studies, including the computational kinetic model at an angle and the

  6. A study on the enhancement of the international environment for nuclear Rand D in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Young Myung; Lee, K. S.; Oh, B. Y.; Lee, H. S.; Yang, M. H.; Kim, H. J.; Song, K. D

    1999-08-01

    The objectives of this study are to identify international environmental factors which could hamper the successful implementation of national nuclear R and D programs and to derive measures of enhancing international nuclear environments confident for Korea's nuclear program to resolve or mitigate possible constraints due to those international factors. To accomplish these objectives, first, this study identifies national needs in the energy field and then in the nuclear field. Second, this study identifies international environmental factors which could hamper the successful implementation of national nuclear R and D programs. Third, this study suggests goals, strategies and measures of enhancing international nuclear environments confident for Korea's nuclear program to resolve possible constraints due to those international factors. (author)

  7. Comparative Analysis of Crack Propagation in Roots with Hand and Rotary Instrumentation of the Root Canal -An Ex-vivo Study

    Science.gov (United States)

    Krishnaswamy, Manjunath Mysore

    2016-01-01

    Introduction Success of any endodontic treatment depends on strict adherence to ‘endodontic triad’. Preparation of root canal system is recognized as being one of the most important stages in root canal treatment. At times, we inevitably end up damaging root dentin which becomes a Gateway for infections like perforation, zipping, dentinal cracks and minute intricate fractures or even vertical root fractures, thereby resulting in failure of treatment. Several factors may be responsible for the formation of dentinal cracks like high concentration of sodium hypochlorite, compaction methods and various canal shaping methods. Aim To compare and evaluate the effects of root canal preparation techniques and instrumentation length on the development of apical root cracks. Materials and Methods Seventy extracted premolars with straight roots were mounted on resin blocks with simulated periodontal ligaments, exposing 1-2 mm of the apex followed by sectioning of 1mm of root tip for better visualization under stereomicroscope. The teeth were divided into seven groups of 10 teeth each – a control group and six experimental groups. Subgroup A & B were instrumented with: Stainless Steel hand files (SS) up to Root Canal Length (RCL) & (RCL –1 mm) respectively; sub group C & D were instrumented using ProTaper Universal (PTU) up to RCL and (RCL -1mm) respectively; subgroup E & F were instrumented using ProTaper Next (PTN) up to RCL & (RCL -1 mm) respectively. Stereomicroscopic images of the instrumentation sequence were compared for each tooth. The data was analyzed statistically using descriptive analysis by ‘Phi’ and ‘Cramers’ test to find out statistical significance between the groups. The level of significance was set at pProTaper Universal & ProTaper Next though statistically not significant. Samples instrumented up to 1mm short of working length (RCL-1mm) showed lesser number of cracks. Conclusion All groups showed cracks formation, the stainless steel group

  8. Studies in High Energy Heavy Ion Nuclear Physics

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, Gerald W. [Univ. of Texas, Austin, TX (United States); Markert, Christina [Univ. of Texas, Austin, TX (United States)

    2016-09-01

    This close-out report covers the period 1994 - 2015 for DOE grant DE-FG02-94ER40845 with the University of Texas at Austin. The research was concerned with studies of the strong nuclear force and properties of nuclear matter under extreme conditions of temperature and density which far exceed that in atomic nuclei. Such extreme conditions are briefly created (for about 10 trillionths of a trillionth of a second) during head-on collisions of large atomic nuclei (e.g. gold) colliding at speeds very close to the speed-of-light. The collisions produce thousands of subatomic particles, many of which are detected in our experiment called STAR at the Relativistic Heavy-Ion Collider at the Brookhaven National Lab in New York. The goal of our research is to learn how the strong nuclear force and its fundamental particles (quarks and gluons) behave in extreme conditions similar to that of the early Universe when it was about 1 micro-second old, and in the cores of very dense neutron stars. To learn anything new about the matter which exists for such a very short amount of time requires carefully designed probes. In our research we focused on two such probes, one being short-lived resonance particles and the other using correlations between pairs of the detected particles. Resonances are short-lived particles created in the collision, which interact with the surrounding matter, and which break apart, or "decay" into more stable particles which survive long enough to be seen in our detectors. The dependence of resonance properties on the conditions in the collision system permit tests of theoretical models and improve our understanding. Dynamical interactions in the matter also leave imprints on the final, outgoing particle distributions measured in the experiment. In particular, angular correlations between pairs of particles can be related to the fundamental strong force as it behaves in the hot, dense matter. Studying correlations as a function of experimentally controlled

  9. Studies in High Energy Heavy Ion Nuclear Physics

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, Gerald W. [Univ. of Texas, Austin, TX (United States); Markert, Christina [Univ. of Texas, Austin, TX (United States)

    2016-09-01

    This close-out report covers the period 1994 - 2015 for DOE grant DE-FG02-94ER40845 with the University of Texas at Austin. The research was concerned with studies of the strong nuclear force and properties of nuclear matter under extreme conditions of temperature and density which far exceed that in atomic nuclei. Such extreme conditions are briefly created (for about 10 trillionths of a trillionth of a second) during head-on collisions of large atomic nuclei (e.g. gold) colliding at speeds very close to the speed-of-light. The collisions produce thousands of subatomic particles, many of which are detected in our experiment called STAR at the Relativistic Heavy-Ion Collider at the Brookhaven National Lab in New York. The goal of our research is to learn how the strong nuclear force and its fundamental particles (quarks and gluons) behave in extreme conditions similar to that of the early Universe when it was about 1 micro-second old, and in the cores of very dense neutron stars. To learn anything new about the matter which exists for such a very short amount of time requires carefully designed probes. In our research we focused on two such probes, one being short-lived resonance particles and the other using correlations between pairs of the detected particles. Resonances are short-lived particles created in the collision, which interact with the surrounding matter, and which break apart, or "decay" into more stable particles which survive long enough to be seen in our detectors. The dependence of resonance properties on the conditions in the collision system permit tests of theoretical models and improve our understanding. Dynamical interactions in the matter also leave imprints on the final, outgoing particle distributions measured in the experiment. In particular, angular correlations between pairs of particles can be related to the fundamental strong force as it behaves in the hot, dense matter. Studying correlations as a function of experimentally controlled

  10. Studies of nuclear processes at the Triangle Universities Nuclear Laboratory. Progress report, 1 September 1994--31 August 1995

    Energy Technology Data Exchange (ETDEWEB)

    Ludwig, E.J.

    1995-09-01

    The Triangle Universities Nuclear Laboratory (TUNL)--a collaboration of Duke University, North Carolina State University, and the University of North Carolina at Chapel Hill--has had a very productive year. This report covers the second year of a three-year grant between the US Department of Energy and the three collaborating universities. The TUNL research program focuses on the following areas of nuclear physics: parity violation in neutron and charged-particle resonances--the mass and energy dependence of the weak interaction spreading width; chaotic behavior in {sup 30}P from studies of eigenvalue fluctuations in nuclear level schemes; studies of few-body systems; nuclear astrophysics; nuclear data evaluation for A = 3--20, for which TUNL is now the international center; high-spin spectroscopy and superdeformation in nuclei, involving collaborations at Argonne National Laboratory. Developments in technology and instrumentation have been vital to the research and training program. In this progress report the author describes: a proposed polarized {gamma}-beam facility at the Duke Free Electron Laser Laboratory; cryogenic systems and microcalorimeter development; continuing development of the Low Energy Beam Facility. The research summaries presented in this progress report are preliminary.

  11. Studies of nuclear processes at the Triangle Universities Nuclear Laboratory. Progress report, 1 September 1995--31 August 1996

    Energy Technology Data Exchange (ETDEWEB)

    Ludwig, E.J.

    1996-09-01

    The Triangle Universities Nuclear Laboratory (TUNL)--a collaboration of Duke University, North Carolina State University, and the University of North Carolina at Chapel Hill--has had a very productive year. This report covers parts of the second and third year of a three-year grant between the US Department of Energy and the three collaborating universities. The TUNL research program focuses on the following areas: precision test of parity-invariance violation in resonance neutron scattering at LANSCE/LANL; parity violation measurements using charged-particle resonances in A = 20--40 targets and the A = 4 system at TUNL; chaotic behavior in the nuclei {sup 30}P and {sup 34}Cl from studies of eigenvalue fluctuations in nuclear level schemes; search for anomalies in the level density (pairing phase transition) in 1f-2p shell nuclei using GEANIE at LANSCE/LANL; parity-conserving time-reversal noninvariance tests using {sup 166}Ho resonances at Geel, ORELA, or LANSCE/LANL; nuclear astrophysics; few-body nuclear systems; Nuclear Data evaluation for A = 3--20 for which TUNL is now the international center. Developments in technology and instrumentation are vital to the research and training program. Innovative work was continued in: polarized beam development; polarized target development; designing new cryogenic systems; designing new detectors; improving high-resolution beams for the KN and FN accelerators; development of an unpolarized Low-Energy Beam Facility for radiative capture studies of astrophysical interest. Preliminary research summaries are presented.

  12. 33 CFR 117.444 - Falgout Canal.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Falgout Canal. 117.444 Section 117.444 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.444 Falgout Canal. The draw of the LA 315 bridge across Falgout Canal, mile 3.1,...

  13. Developmental spinal canal stenosis and somatotype.

    OpenAIRE

    Nightingale, S.

    1989-01-01

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

  14. A study on nuclear specific material detection technique using nuclear resonance reactions

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Y. K.; Ha, J. H.; Cho, Y. S.; Choi, B. H. [KAERI, Taejon (Korea, Republic of)

    2001-10-01

    The non-destructive nuclear material detection technique is one of the novel methods under somewhat dangerous environments, for example, high level radiation or landmine areas. Specially, the detection of a landmine is a hot issue on the peaceful use of nuclear technology for human welfare. Generally, the explosives contain specific elements such as {sup 14}N or {sup 35}Cl. The photo-nuclear resonance gamma-rays are produced by nuclear reaction {sup 13}C(p , {gamma}){sup 14}N or {sup 34}S(p, {gamma}){sup 35}Cl in which target is bombarded by about 2MeV proton beam extracted from the proton accelerator. To avoid other neighboring resonant gamma-rays, we selected a higher resonant energy above 5MeV. The resonance gamma rays produced are absorbed or scattered when they react with {sup 14}N or {sup 35}Cl included in the mines and explosive. We can determine existence and position of mines or explosives by detecting the absorption and scattering gamma-ray signals.

  15. Feasibility Study of Hydrogen Production at Existing Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Stephen Schey

    2009-07-01

    Cooperative Agreement DE-FC07-06ID14788 was executed between the U.S. Department of Energy, Electric Transportation Applications, and Idaho National Laboratory to investigate the economics of producing hydrogen by electrolysis using electricity generated by nuclear power. The work under this agreement is divided into the following four tasks: Task 1 – Produce Data and Analyses Task 2 – Economic Analysis of Large-Scale Alkaline Electrolysis Task 3 – Commercial-Scale Hydrogen Production Task 4 – Disseminate Data and Analyses. Reports exist on the prospect that utility companies may benefit from having the option to produce electricity or produce hydrogen, depending on market conditions for both. This study advances that discussion in the affirmative by providing data and suggesting further areas of study. While some reports have identified issues related to licensing hydrogen plants with nuclear plants, this study provides more specifics and could be a resource guide for further study and clarifications. At the same time, this report identifies other area of risks and uncertainties associated with hydrogen production on this scale. Suggestions for further study in some of these topics, including water availability, are included in the report. The goals and objectives of the original project description have been met. Lack of industry design for proton exchange membrane electrolysis hydrogen production facilities of this magnitude was a roadblock for a significant period. However, recent design breakthroughs have made costing this facility much more accurate. In fact, the new design information on proton exchange membrane electrolyzers scaled to the 1 kg of hydrogen per second electrolyzer reduced the model costs from $500 to $100 million. Task 1 was delayed when the original electrolyzer failed at the end of its economic life. However, additional valuable information was obtained when the new electrolyzer was installed. Products developed during this study

  16. Nuclear space power safety and facility guidelines study

    Energy Technology Data Exchange (ETDEWEB)

    Mehlman, W.F.

    1995-09-11

    This report addresses safety guidelines for space nuclear reactor power missions and was prepared by The Johns Hopkins University Applied Physics Laboratory (JHU/APL) under a Department of Energy grant, DE-FG01-94NE32180 dated 27 September 1994. This grant was based on a proposal submitted by the JHU/APL in response to an {open_quotes}Invitation for Proposals Designed to Support Federal Agencies and Commercial Interests in Meeting Special Power and Propulsion Needs for Future Space Missions{close_quotes}. The United States has not launched a nuclear reactor since SNAP 10A in April 1965 although many Radioisotope Thermoelectric Generators (RTGs) have been launched. An RTG powered system is planned for launch as part of the Cassini mission to Saturn in 1997. Recently the Ballistic Missile Defense Office (BMDO) sponsored the Nuclear Electric Propulsion Space Test Program (NEPSTP) which was to demonstrate and evaluate the Russian-built TOPAZ II nuclear reactor as a power source in space. As of late 1993 the flight portion of this program was canceled but work to investigate the attributes of the reactor were continued but at a reduced level. While the future of space nuclear power systems is uncertain there are potential space missions which would require space nuclear power systems. The differences between space nuclear power systems and RTG devices are sufficient that safety and facility requirements warrant a review in the context of the unique features of a space nuclear reactor power system.

  17. Study on Seal Technology for Nuclear Material Control

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The seals have important application in nuclear safeguards, and are designed to record unauthorizedaccess or entry to inspected material and equipment. They can provide assurance for the continuity andintegrity of nuclear material accountancy. It is very useful to improve the inspection efficiency by means

  18. 基于关联耦合法的城市运河景观生态规划初探--以南京秦淮新河为例%The Study of Ecological Planning of City Canal Landscape Based on the Linkage Method--A Case Study of Qinhuai New River

    Institute of Scientific and Technical Information of China (English)

    王淼; 徐晨; 丁山

    2015-01-01

    聚焦城市运河景观,以南京秦淮新河为例,使用关联耦合法的方法,选取生态驳岸、缓冲带、慢行系统和园林小品四个方面进行论述,探索城市运河景观的规划方法,为当前城市运河开发建设提供有益的借鉴与参考。%This paper examines city canal landscape. Trough a case study of QinHuai new river, using the method of linkage theory, it discusses four aspects of ecological revetment, bufer zone, slow system and landscape pieces. This article tries to point out the planning method of city canal landscape, which providing useful reference to the curent city development and canal construction.

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

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Yun Hoa; Cho, Bong Hae [Dept. of Oral and Maxillofacial Radiology, School of Dentistry, Pusan National University, Yangsan (Korea, Republic of)

    2014-12-15

    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.

  20. Topographical evaluation of the mandibular canal through panoramic radiograph

    Directory of Open Access Journals (Sweden)

    Ingrid Macedo Oliveira

    2016-10-01

    Full Text Available The mandibular canal is located inside the body of the mandible and may have anatomical variations. The topographic knowledge of the mandibular canal by the Dental surgeons is fundamental to achieving success in surgical planning, anesthetics and clinical interventions involving the jaw. To study the anatomy of the mandibular canal through panoramic radiographs. A retrospective descriptive study, developed after review and approval by the Ethics and Research Committee with the number of opinion 431095. Were analyzed 252 panoramic radiographs of patients of male and female attended in dental clinics UNINOVAFAPI University Center, Teresina-Pi, Brazil. The radiographs were analyzed with the aid of a light box and each antimere the jaw was observed separately. The classification of Nortjé and Langlais for description of the topography of the mandibular canal were used. Descriptive statistical analysis was performed with SPSS version 18.0. There was a prevalence of 38.89% in both antimeres, of mandibular channel the Type II. The type IV was present in 25.4% in the right hemi-arch and 26.6% on the left. Mandibular canal with unilateral bifurcation was observed in 0.77% of the sample and molar straight channel has not been identified. We observed anatomical variations as for the number and path, of the mandibular canal with the highest prevalence of Types II and IV, and the absence of bifurcations. Most was mandibular channels showed no bifurcation. The panoramic radiograph showed up an aid important to identify the mandibular canal and its variations.

  1. 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

  2. [Endodontic microbiology: antimicrobial canal medications].

    Science.gov (United States)

    Seltzer, S; Farber, P A

    1989-06-01

    Medicaments used for reducing or eliminating microorganisms from infected root canals include: irrigating solutions, such as sodium hypochlorite, urea peroxide and hydrogen peroxide, chloramine, iodine-potassium-iodide solution, and chlorhexidine solution. In addition, various intracanal drugs, such as calcium hydroxide and antibiotics, are in use. The characteristics of these drugs are discussed.

  3. Novel nuclear magnetic resonance techniques for studying biological molecules

    Energy Technology Data Exchange (ETDEWEB)

    Laws, David Douglas [Univ. of California, Berkeley, CA (United States)

    2000-06-01

    Over the fifty-five year history of Nuclear Magnetic Resonance (NMR), considerable progress has been made in the development of techniques for studying the structure, function, and dynamics of biological molecules. The majority of this research has involved the development of multi-dimensional NMR experiments for studying molecules in solution, although in recent years a number of groups have begun to explore NMR methods for studying biological systems in the solid-state. Despite this new effort, a need still exists for the development of techniques that improve sensitivity, maximize information, and take advantage of all the NMR interactions available in biological molecules. In this dissertation, a variety of novel NMR techniques for studying biomolecules are discussed. A method for determining backbone (Φ/Ψ) dihedral angles by comparing experimentally determined 13Ca, chemical-shift anisotropies with theoretical calculations is presented, along with a brief description of the theory behind chemical-shift computation in proteins and peptides. The utility of the Spin-Polarization Induced Nuclear Overhauser Effect (SPINOE) to selectively enhance NMR signals in solution is examined in a variety of systems, as are methods for extracting structural information from cross-relaxation rates that can be measured in SPINOE experiments. Techniques for the production of supercritical and liquid laser-polarized xenon are discussed, as well as the prospects for using optically pumped xenon as a polarizing solvent. In addition, a detailed study of the structure of PrP 89-143 is presented. PrP 89-143 is a 54 residue fragment of the prion proteins which, upon mutation and aggregation, can induce prion diseases in transgenic mice. Whereas the structure of the wild-type PrP 89-143 is a generally unstructured mixture of α-helical and β-sheet conformers in the solid state, the aggregates formed from the PrP 89-143 mutants appear to be mostly β-sheet.

  4. Comparison of canal transportation and centering ability of hand Protaper files and rotary Protaper files by using micro computed tomography

    OpenAIRE

    Amit Gandhi; Taru Gandhi

    2011-01-01

    Introduction and objective: The aim of the present study was to compare root canal preparation with rotary ProTaper files and hand ProTaper files to find a better instrumentation technique for maintaining root canal geometry with the aid of computed tomography. Material and methods: Twenty curved root canals with at least 10 degree of curvature were divided into 2 groups of 10 teeth each. In group I the canals were prepared with hand ProTaper files and in group II the canals were prepared wit...

  5. Nuclear magnetic resonance imaging of the spine

    Energy Technology Data Exchange (ETDEWEB)

    Modic, M.T.; Weinstein, M.A.; Pavlicek, W.; Starnes, D.L.; Duchesneau, P.M.; Boumphrey, F.; Hardy, R.J. Jr.

    1984-01-01

    Forty subjects were examined to determine the accuracy and clinical usefulness of nuclear magnetic resonance (NMR) examination of the spine. The NMR images were compared with plain radiographs, high-resolution computed tomograms, and myelograms. The study included 15 patients with normal spinal cord anatomy and 25 patients whose pathological conditions included canal stenosis, herniated discs, metastatic tumors, primary cord tumor, trauma, Chiari malformations, syringomyelia, and developmental disorders. Saturation recovery images were best in differentiating between soft tissue and cerebrospinal fluid. NMR was excellent for the evaluation of the foramen magnum region and is presently the modality of choice for the diagnosis of syringomyelia and Chiari malformation. NMR was accurate in diagnosing spinal cord trauma and spinal canal block.

  6. 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

  7. A study on the development and application of expert system for nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Woo, Hee Gon; Kim, Seong Bok [Korea Electric Power Corp. (KEPCO), Taejon (Korea, Republic of). Research Center

    1995-12-31

    It is a final report of the research that is a study on the development and application of expert system for nuclear power plants and development of the schemes computing environments and user interfaces for the expert system, which is a systematic and efficient development of expert system for nuclear power plants in the future. This report is consisted of -Development trends of expert system for nuclear power plants. -Classification of expert system applications for nuclear power plants. -Systematic and efficient developments schemes of expert system for nuclear power plants, and -Suitable computing environments and user interfaces for the expert systems. (author). 113 refs., 85 figs.

  8. Historic images in nuclear medicine: 1976: the first issue of clinical nuclear medicine and the first human FDG study.

    Science.gov (United States)

    Hess, Søren; Høilund-Carlsen, Poul Flemming; Alavi, Abass

    2014-08-01

    In 1976, 2 major molecular imaging events coincidentally took place: Clinical Nuclear Medicine was first published in June, and in August researchers at the Hospital of the University of Pennsylvania created the first images in humans with F-FDG. FDG was initially developed as part of an evolution set in motion by fundamental research studies with positron-emitting tracers in the 1950s by Michel Ter-Pegossian and coworkers at the Washington University. Today, Clinical Nuclear Medicine is a valued scientific contributor to the molecular imaging community, and FDG PET is considered the backbone of this evolving and exciting discipline.

  9. Nuclear study of Melusine; Etude nucleaire de Melusine

    Energy Technology Data Exchange (ETDEWEB)

    Cherot, J. [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1959-07-01

    In this report are reviewed - with respect to starting of experiments - the main nuclear characteristics of a 20 per cent enriched uranium lattice, with light water as moderator and reflector. The reactor is to operate at 1 MW. 1) Study of various critical masses. 2) Control. Effectiveness of cadmium. Control rods and of a stainless steel regulating rod. 3) Study of the effect on reactivity of disturbances in the core center. 4) Study of xenon and samarium poisoning. 5) Temperature factor. 6) Heat exchanges in a fuel element. (author) [French] On etudie, dans ce rapport, les principales proprietes nucleaires d'un reseau a uranium enrichi (20 pour cent), dont le moderateur et le reflecteur sont l'eau legere en vue des experiences de demarrage. Ce reacteur devra fonctionner a 1 MW. 1) Etude de diverses masses critiques. 2) Controle. Efficacite des barres de controle en cadmium et d'une barre de reglage en acier inoxydable. 3) Etude de l'effet sur la reactivite de perturbation au centre du coeur. 4) Etude de l'empoisonnement xenon et samarium. 5) Coefficient de temperature. 6) Echanges thermiques dans un element. (auteur)

  10. Dissolution Dynamic Nuclear Polarization capability study with fluid path

    Science.gov (United States)

    Malinowski, Ronja M.; Lipsø, Kasper W.; Lerche, Mathilde H.; Ardenkjær-Larsen, Jan H.

    2016-11-01

    Signal enhancement by hyperpolarization is a way of overcoming the low sensitivity in magnetic resonance; MRI in particular. One of the most well-known methods, dissolution Dynamic Nuclear Polarization, has been used clinically in cancer patients. One way of ensuring a low bioburden of the hyperpolarized product is by use of a closed fluid path that constitutes a barrier to contamination. The fluid path can be filled with the pharmaceuticals, i.e. imaging agent and solvents, in a clean room, and then stored or immediately used at the polarizer. In this study, we present a method of filling the fluid path that allows it to be reused. The filling method has been investigated in terms of reproducibility at two extrema, high dose for patient use and low dose for rodent studies, using [1-13C]pyruvate as example. We demonstrate that the filling method allows high reproducibility of six quality control parameters with standard deviations 3-10 times smaller than the acceptance criteria intervals in clinical studies.

  11. NATO Advanced Study Institute on New Aspects of Nuclear Dynamics

    CERN Document Server

    Huberts, P

    1989-01-01

    The 1988 Summer School on New Aspects of Nuclear Dynamics took place in the style that by now has become a tradition: a series of lectures by well known scientists on modem topics of nuclear physics, where special emphasis is placed on the didactic aspects of the lectures. In the past few years, we have witnessed a rapid evolution of the field of nuclear physics towards novel directions of research. This development is accompanied by the construction of some of the largest experimental facilities ever built for nuclear research. The subjects covered by the Summer School focussed on two main issues currently under active investigation and which will be pursued with the new facilities: the transition from nucleonic to quark degrees of freedom in the decription of nuclear reactions, and the behavior of nuclear matter as one approaches extreme densities and temperatures. These topics in many respects go beyond traditional nuclear physics and the speakers therefore also included high energy physicists. From the re...

  12. Estudo anatomotopográfico do canal arterial em fetos natimortos dirigido para sua abordagem por videotoracoscopia Anatomotopographic study of ductus arteriosus in newborn cadavers directed for its videotoracoscopic approach

    Directory of Open Access Journals (Sweden)

    Josué Viana de Castro Neto

    2001-03-01

    Full Text Available Este trabalho objetiva realizar um estudo anatomotopográfico do Canal Arterial em fetos natimortos enfatizando o seu comprimento e seu diâmetro de acordo com o tamanho de cada feto. Além de que, descrevemos as distâncias entre este e pontos de reparo importantes para sua abordagem por videotoracoscopia. Estudamos dezesseis fetos natimortos, sendo que oito eram do sexo masculino. O tamanho do feto e os perímetros torácico e cefálico variaram de 42-57, 26-35 e 29-35,5 cm, respectivamente. A média de comprimento e diâmetro foram 11,06 e 5,56 cm. Distâncias entre o Canal e as seguintes estruturas: clavícula-22,13mm, segunda costela-20,75mm, esterno-33,88mm e a.subclávia esquerda-5,30mm. Acreditamos que as medidas apresentadas podem facilitar a abordagem do canal por videotoracoscopia.The purpose of this work is to realize an anatomic and topographic study of the ductus arteriosus in newborn cadavers emphasizing its lenght and diameter according to each size of the newborn cadaver. We also describe distances between the ductus and important structures for thoracoscopic approach. We study sixteen newborn cadavers. Eight were male. Size of the cadavers, thoracic and cephalic perimeters ranged from 42-47,26-35 and 29-35,5 cm, respectively. Median lenght and diameter were 11,06 and 5,56 mm. Distances between ductus arteriosus and follow structures were: collarbone-22,13mm, second rib-20,75mm, sternum-33,88mm and left subclavian artery-5,30mm. We belived that these distances described can facilitate thoracoscopic surgical approach to the ductus arteriosus.

  13. 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

  14. Mandibular Second Premolar with Four Canals

    Directory of Open Access Journals (Sweden)

    Javad Ghiasi

    2015-09-01

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

  15. A Study on the Economic Feasibility of Nuclear Power Caused by Fukushima Nuclear Power Accident

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dongwon [Korea Nuclear Energy Promotion Agency, Seoul (Korea, Republic of)

    2013-05-15

    It would be necessary to utilize the economic competitiveness of the generation cost calculated based on the previous power plant generation cost and the overall safety related costs taken into account after the Fukushima incident, i. e. expenses related to safety facilities, legal restrictions, environmental expenses and social expenses for the mid and long-term strategy establishment of energy. The above conclusion is premised on utilizing the levelized generation cost method, base load operation (based on a certain utilization rate), straight-line depreciation method, etc. However, this thesis would be significantly meaningful at this point where the general public, including civic groups, etc. are concerned with the economic feasibility and safety of nuclear power plant, and that even after considering the social expenses such as safety related expenses after the Fukushima incident, the generation cost of nuclear power plant still remains competitive.

  16. 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.

  17. Histological analysis of cleaning efficacy of hand and rotary instruments in the apical third of the root canal: A comparative study

    OpenAIRE

    Ashtha Arya; Dildeep Bali; Grewal, Mandeep S

    2011-01-01

    Aim: To compare the cleaning efficiency of manual and rotary instrumentation in the apical third of the root canal system. Materials and Methods: In group 1 (n=10), instrumentation was performed with stainless steel K-file; in group 2 (n=10), it was done with hand ProTaper files; and in group 3 (n=10), instrumentation was done with ProTaper rotary. Distilled water was used for irrigation. The apical third was sectioned transversally and histologically processed. The cross sections were ex...

  18. Cleaning and shaping curved root canals: Mtwo® vs ProTaper® instruments, a lab comparison

    Directory of Open Access Journals (Sweden)

    Kuzekanani Maryam

    2009-01-01

    Full Text Available Objectives: The purpose of this study was to compare root canal preparation in curved canals in molar teeth with the rotary NiTi Mtwo and ProTaper systems in terms of canal shape and smear layer. Materials and Methods: Mesiobuccal canals of 60 molar teeth with angles of curvature between 25 and 35 degrees were prepared with a torque controlled low speed engine; 30 canals for each system. Each individual instrument was used to prepare four root canals and the time required for preparation was recorded. Standardized radiographs were taken before and following instrumentation and used to determine changes in canal curvature. Results: There was no significant difference in preparation time between the two systems. No instruments separated during use. The Mtwo system gave a statistically smaller change in canal curvature and thus was better for maintaining the original shape of the root canal, with less transportation (P less than 0.05. The greatest difference was seen for maxillary molar teeth. When prepared root canals were examined by SEM there was no difference between the two systems at the coronal, middle or apical thirds. Conclusion: Overall, the results of this study suggest that Mtwo instruments are preferable for situations where canals are curved, particularly for maxillary molars.

  19. Nuclear structure and reaction studies at medium energies

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, G.W.; Ray, R.L.

    1990-10-01

    This document constitutes the (1988--1991) technical progress report for the ongoing medium energy physics research program supported by the US Department of Energy through special Research Grant FG05-88ER40444. The experiments discussed are conducted at the Los Alamos National Laboratory's (LANL) Clinton P. Anderson Meson Physics Facility (LAMPF), the Alternating Gradient Synchrotron (AGS) facility of the Brookhaven National Laboratory (BNL), and at the Fermi National Accelerator Laboratory (FNAL). The overall motivation for the work discussed in this document is driven by three main objectives: (1) provide hadron-nucleon and hadron-nucleus scattering data which serve to facilitate the study of effective two-body interactions, test (and possibly determine) nuclear structure, and help study reaction mechanisms and dynamics;(2) provide unique, first-of-a-kind exploratory'' hadron-nucleus scattering data in the hope that such data will lead to discovery of new phenomena and new physics; and (3) perform precision tests of fundamental interactions, such as rare decay searches, whose observation would imply fundamental new physics.

  20. Study on Nuclear Accident Precursors Using AHP and BBN

    Directory of Open Access Journals (Sweden)

    Sujin Park

    2014-01-01

    Full Text Available Most of the nuclear accident reports used to indicate the implicit precursors which are not easily quantified as underlying factors. The current Probabilistic Safety Assessment (PSA is capable of quantifying the importance of accident causes in limited scope. It was, therefore, difficult to achieve quantifiable decision-making for resource allocation. In this study, the methodology which facilitates quantifying these precursors and a case study were presented. First, four implicit precursors have been obtained by evaluating the causality and hierarchy structure of various accident factors. Eventually, it turned out that they represent the lack of knowledge. After four precursors are selected, subprecursors were investigated and their cause-consequence relationship was implemented by Bayesian Belief Network (BBN. To prioritize the precursors, the prior probability is initially estimated by expert judgment and updated upon observations. The pair-wise importance between precursors is calculated by Analytic Hierarchy Process (AHP and the results are converted into node probability tables of the BBN model. Using this method, the sensitivity and the posterior probability of each precursor can be analyzed so that it enables making prioritization for the factors. We tried to prioritize the lessons learned from Fukushima accident to demonstrate the feasibility of the proposed methodology.

  1. A study on the enhancement of nuclear cooperation with African countries including utilization of radioisotope

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Maeng Ho; Oh, K. B; Lee, H. M. and others

    2005-05-15

    In this study, potential countries for nuclear cooperation in African region and possible cooperation areas were investigated between Korea and African countries including radioisotopes and more fields were also analysed in depth in order to suggest the recommendations for future cooperation to be considered as follows; First, current status and perspectives of demand and supply of energy and electricity in the African countries, use and development of nuclear energy and international nuclear cooperation were analyzed. Second, current status of nuclear cooperation between Korea and African countries were investigated as well as analysis of future cooperation potential and countries having potential for nuclear cooperation and possible cooperative activities were suggested considering potential of nuclear market in mid- and long term base and step by step. Third, desirable strategies and directions for the establishment and promotion of nuclear cooperation relations between Korea and African developing countries were suggested in order to develope cooperative relations in efficient and effective manners with African developing countries.

  2. Nanodiamond-Gutta Percha Composite Biomaterials for Root Canal Therapy.

    Science.gov (United States)

    Lee, Dong-Keun; Kim, Sue Vin; Limansubroto, Adelheid Nerisa; Yen, Albert; Soundia, Akrivoula; Wang, Cun-Yu; Shi, Wenyuan; Hong, Christine; Tetradis, Sotirios; Kim, Yong; Park, No-Hee; Kang, Mo K; Ho, Dean

    2015-11-24

    Root canal therapy (RCT) represents a standard of treatment that addresses infected pulp tissue in teeth and protects against future infection. RCT involves removing dental pulp comprising blood vessels and nerve tissue, decontaminating residually infected tissue through biomechanical instrumentation, and root canal obturation using a filler material to replace the space that was previously composed of dental pulp. Gutta percha (GP) is typically used as the filler material, as it is malleable, inert, and biocompatible. While filling the root canal space with GP is the standard of care for endodontic therapies, it has exhibited limitations including leakage, root canal reinfection, and poor mechanical properties. To address these challenges, clinicians have explored the use of alternative root filling materials other than GP. Among the classes of materials that are being explored as novel endodontic therapy platforms, nanodiamonds (NDs) may offer unique advantages due to their favorable properties, particularly for dental applications. These include versatile faceted surface chemistry, biocompatibility, and their role in improving mechanical properties, among others. This study developed a ND-embedded GP (NDGP) that was functionalized with amoxicillin, a broad-spectrum antibiotic commonly used for endodontic infection. Comprehensive materials characterization confirmed improved mechanical properties of NDGP over unmodified GP. In addition, digital radiography and microcomputed tomography imaging demonstrated that obturation of root canals with NDGP could be achieved using clinically relevant techniques. Furthermore, bacterial growth inhibition assays confirmed drug functionality of NDGP functionalized with amoxicillin. This study demonstrates a promising path toward NDGP implementation in future endodontic therapy for improved treatment outcomes.

  3. Nuclear magnetic resonance studies of macroscopic morphology and dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Barrall, Geoffrey Alden [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry

    1995-09-01

    Nuclear magnetic resonance techniques are traditionally used to study molecular level structure and dynamics with a noted exception in medically applied NMR imaging (MRI). In this work, new experimental methods and theory are presented relevant to the study of macroscopic morphology and dynamics using NMR field gradient techniques and solid state two-dimensional exchange NMR. The goal in this work is not to take some particular system and study it in great detail, rather it is to show the utility of a number of new and novel techniques using ideal systems primarily as a proof of principle. By taking advantage of the analogy between NMR imaging and diffraction, one may simplify the experiments necessary for characterizing the statistical properties of the sample morphology. For a sample composed of many small features, e.g. a porous medium, the NMR diffraction techniques take advantage of both the narrow spatial range and spatial isotropy of the sample`s density autocorrelation function to obtain high resolution structural information in considerably less time than that required by conventional NMR imaging approaches. The time savings of the technique indicates that NMR diffraction is capable of finer spatial resolution than conventional NMR imaging techniques. Radio frequency NMR imaging with a coaxial resonator represents the first use of cylindrically symmetric field gradients in imaging. The apparatus as built has achieved resolution at the micron level for water samples, and has the potential to be very useful in the imaging of circularly symmetric systems. The study of displacement probability densities in flow through a random porous medium has revealed the presence of features related to the interconnectedness of the void volumes. The pulsed gradient techniques used have proven successful at measuring flow properties for time and length scales considerably shorter than those studied by more conventional techniques.

  4. The study for the high qualification of international nuclear training

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Byong Chull; Kim, Hyun Jin

    2012-12-15

    It is suggested how to reach high qualification of KAERI international nuclear training and how to play a leading role for new paradigm on the international training on the world. 1. The formulation of the core nuclear training framework- The systematic formulation of nuclear training framework based on the existing turning course design 2. Planning and operation of KAERI- Excellent Technology Series training course- The advertisement for KAERI Excellent Technology through the continuous international training and the future market development on the world for the nuclear technology 3. e-Learning training contents development- e-Learning training contents development to play a leading role for new training paradigm on the world and to overcome the limit of time/spacy.

  5. Nuclear techniques using radioactive beams for biophysical studies

    CERN Document Server

    Stachura, Monika Kinga

    Perturbed angular correlation of "-rays (PAC) spectroscopy and nuclear magnetic resonance measured by !-decay (betaNMR) spectroscopy are two very sensitive and, among life-scientists, infrequently encountered nuclear techniques. Both of them belong to the family of hyperfine techniques, which allow for measurements of the interactions of extra-nuclear electromagnetic fields with the nuclear moments. In this way - they can provide useful information about the local structure of the investigated systems. The first part of the work presented here focuses on investigating the fundamental chemistry of heavy metal ion - protein interactions mainly with PAC spectroscopy. A variety of questions concerning both the function of metal ions in natural systems and in synthetic biomolecules on the one hand and the toxic effects of some metal ions on the other were addressed, the results of which are described in four different papers. Paper I is a review article entitled ”Selected applications of perturbed angular correl...

  6. Functional renormalization group studies of nuclear and neutron matter

    CERN Document Server

    Drews, Matthias

    2016-01-01

    Functional renormalization group (FRG) methods applied to calculations of isospin-symmetric and asymmetric nuclear matter as well as neutron matter are reviewed. The approach is based on a chiral Lagrangian expressed in terms of nucleon and meson degrees of freedom as appropriate for the hadronic phase of QCD with spontaneously broken chiral symmetry. Fluctuations beyond mean-field approximation are treated solving Wetterich's FRG flow equations. Nuclear thermodynamics and the nuclear liquid-gas phase transition are investigated in detail, both in symmetric matter and as a function of the proton fraction in asymmetric matter. The equations of state at zero temperature of symmetric nuclear matter and pure neutron matter are found to be in good agreement with advanced ab-initio many-body computations. Contacts with perturbative many-body approaches (in-medium chiral perturbation theory) are discussed. As an interesting test case, the density dependence of the pion mass in the medium is investigated. The questio...

  7. 口腔根管治疗80例牙髓根尖周病的临床疗效研究%The Clinical Efficacy Study of Dental Root Canal Therapy of 80 Cases with Dental Pulp Periapical Disease

    Institute of Scientific and Technical Information of China (English)

    陆丽荣

    2015-01-01

    were selected as the compare group,who treated with the choice of a one-time root canal therapy,their remaining 40 cases of patients with the use of endodontic root canal treatment graded methods of treatment were selected as the study group.Finally,the treatment effect of the two groups were compared.Result:The quality of the dental root canal therapy of the compare group was higher than that of the study group, the total effective rate of the compare group was 100%, and the study group was only 85.0%.The dental recovery time of the compare group was (10.25±2.50) days,the dental inflammation subsidise time was (12.50±3.50) days;The dental recovery time of the study group was (15.50±4.50) days,the dental inflammation subsidise time was (18.50±2.50) days.The differences were statistically significant(P<0.05).The curative effect of the disposable root canal treatment was better than the fractional root canal treatment,and the effect of the dental pulp periapical disease was more noticeable. Conclusion:The treatment effect of dental root canal therapy of the dental pulp periapical disease is good,in reality, the clinical diagnosis and treatment of patients must be closely combined with the actual situation of the appropriate choice of oral root canal treatment.

  8. Theoretical studies in medium-energy nuclear and hadronic physics

    Energy Technology Data Exchange (ETDEWEB)

    Horowitz, C.J.; Macfarlane, M.H.; Matsui, Tetsuo; Serot, B.D.

    1991-12-03

    In the period covered by this report (April 1, 1991 to March 31, 1992), work focused on six main areas: (1) Relativistic Theories of Nuclear Structure and Saturation, (2) Relativistic Descriptions of Proton-Nucleus and Electron-Nucleus Scattering, (3) Nonrelativistic Theory of Nucleon-Nucleus Reactions, (4) Relativistic Many-Body Theory at Finite Temperature and Density, (5) Neutrino Interactions in Dense Matter, (6) Quark Models of Nuclear and Quark Matter.

  9. The role of cone beam computed tomography in the endodontic management of a mandibular first molar with three distal canals

    Directory of Open Access Journals (Sweden)

    Aishvarya Kaushik

    2014-01-01

    Full Text Available The presence of three root canals in the distal root of the mandibular first permanent molars is rare; 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 extra canals and complex canal configurations has become more precise. CBCT provides three dimensional visualization of the pulp canal space, allowing the clinician in determining the spatial relationships of the root canals with each other at various cross sectional levels along the length of the root. The present report discusses the endodontic management of a mandibular first permanent molar with three canals in the distal root, employing CBCT as an adjunctive diagnostic aid to conventional radiography.

  10. 75 FR 39632 - Regulated Navigation Area; Gulf Intracoastal Waterway, Inner Harbor Navigation Canal, Harvey...

    Science.gov (United States)

    2010-07-12

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

  11. 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.

  12. Cancer incidence in the Love Canal area.

    Science.gov (United States)

    Janerich, D T; Burnett, W S; Feck, G; Hoff, M; Nasca, P; Polednak, A P; Greenwald, P; Vianna, N

    1981-06-19

    Data from the New York Cancer Registry show no evidence for higher cancer rates associated with residence near the Love Canal toxic waste burial site in comparison with the entire state outside of New York City. Rates of liver cancer, lymphoma, and leukemia, which were selected for special attention, were not consistently elevated. Among the other cancers studied, a higher rate was noted only for respiratory cancer, but it was not consistent across age groups and appeared to be related to a high rate for the entire city of Niagara Falls. There was no evidence that the lung cancer rate was associated with the toxic wastes buried at the dump site.

  13. Difficulties in Probing Nuclear Physics: A Study of $^{44}$Ti and $^{56}$Ni

    CERN Document Server

    Hungerford, Aimee; Timmes, Francis X; Young, Patrick; Bennett, Michael; Diehl, Steven; Herwig, Falk; Hirschi, Raphael; Pignatari, Marco; Magkotsios, Georgios; Rockefeller, Gabriel

    2008-01-01

    The nucleosynthetic yield from a supernova explosion depends upon a variety of effects: progenitor evolution, explosion process, details of the nuclear network, and nuclear rates. Especially in studies of integrated stellar yields, simplifications reduce these uncertainties. But nature is much more complex, and to actually study nuclear rates, we will have to understand the full, complex set of processes involved in nucleosynthesis. Here we discuss a few of these complexities and detail how the NuGrid collaboration will address them.

  14. 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

  15. BWR Spent Nuclear Fuel Interfacial Bonding Efficiency Study

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jy-An John [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Jiang, Hao [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-04-30

    The objective of this project is to perform a systematic study of spent nuclear fuel (SNF, also known as “used nuclear fuel” [UNF]) integrity under simulated transportation environments using the Cyclic Integrated Reversible-Bending Fatigue Tester (CIRFT) hot-cell testing technology developed at Oak Ridge National Laboratory (ORNL) in August 2013. Under Nuclear Regulatory Commission (NRC) sponsorship, ORNL completed four benchmark tests, four static tests, and twelve dynamic or cycle tests on H. B. Robinson (HBR) high burn-up (HBU) fuel. The clad of the HBR fuels was made of Zircaloy-4. Testing was continued in fiscal year (FY) 2014 using Department of Energy (DOE) funds. Additional CIRFT testing was conducted on three HBR rods; two specimens failed, and one specimen was tested to over 2.23 × 107 cycles without failing. The data analysis on all the HBR SNF rods demonstrated that it is necessary to characterize the fatigue life of the SNF rods in terms of (1) the curvature amplitude and (2) the maximum absolute of curvature extremes. The maximum extremes are significant because they signify the maximum tensile stress for the outer fiber of the bending rod. CIRFT testing has also addressed a large variation in hydrogen content on the HBR rods. While the load amplitude is the dominant factor that controls the fatigue life of bending rods, the hydrogen content also has an important effect on the lifetime attained at each load range tested. In FY 15, eleven SNF rod segments from the Limerick BWR were tested using the ORNL CIRFT equipment; one test under static conditions and ten tests under dynamic loading conditions. Under static unidirectional loading, a moment of 85 N·m was obtained at a maximum curvature of 4.0 m-1. The specimen did not show any sign of failure during three repeated loading cycles to a similar maximum curvature. Ten cyclic tests were conducted with amplitudes varying from 15.2 to 7.1 N·m. Failure was observed in nine of

  16. 小下颌畸形患儿下颌神经管CT解剖特征%Mandibular canal's anatomy in children with micrognathia: a computed tomography study

    Institute of Scientific and Technical Information of China (English)

    李建明; 崔颖秋; 徐文彪; 张靖; 李鹤虹; 艾斌; 吴慧莹; 邝民伟; 谢君宜

    2014-01-01

    Objective To assess the anatomy feature of mandibular canal in children with micrognathia by CT scanning.Methods Three thickness indexes of mandibular canal were measured in 36 cases of children with micrognathia on mandible's coronary CT,including the distance between the mandibular canal and the external surfaces of the mandible (buccal,lingual,and inferior) on each molar regions; the data were analyzed by SPSS13.0 software.Results The mean and standard deviation of three thickness indexes (buccal,lingual,and inferior) were as follows:in the second premolar area:(4.71±1.25),(2.77±1.02),(2.92±0.83) mm; in the first molar area:(2.64±0.99),(4.33±1.12),(2.38±0.72) mm; in the second molar area:(2.44±0.76),(4.20±0.89),(3.38±1.31) mm.There were no significant differences about all the indexes between left and right side.From the second premolar area to second molar area,mandibular canal locating at lingual side accounted for 94.4% (68 sides),and locating at buccal side acounted for 5.6% (4 sides).Mental foramen locating between the first and second premolar area acounted for 76.3% (55 sides),and 23.7% (17 sides) of mental foramen located in the second premolar area.The mandibular canal with a branch accounted for 3.5% (3 sides).Conclusions Mandibular canal arises from mandibular foramen,courses the mandible on the inferior and lingual side,and ends in mental foremen.Some anatomical variations of mandibular canal should be noticed by the surgeons,such as a branch line of mandibular canal,coursing on the buccal side,with position of mental foremen moving backward.%目的 探讨小下颌畸形患儿下颌神经管的CT解剖特征.方法 在36例小下颌畸形患儿下颌骨冠状位CT图像上,分区测量下颌神经管内缘与下颌骨舌侧骨壁(舌侧指数)、外缘与颊侧骨壁(颊侧指数)、下缘与下颌骨下缘(下缘指数)间的距离.结果 第2前磨牙下颌神经管舌侧、颊侧和下缘的骨壁厚度指数为(4.71±1.25)、(2

  17. Comparative analysis of SAF, Protaper Next and BT-Race in eliminating Enterococcus faecalis from long oval canals: An ex vivo study.

    Science.gov (United States)

    Krokidis, Andreas; Bonfanti, Carlo; Cerutti, Antonio; Barabanti, Nicola; Zinelis, Spyros; Panopoulos, Panos

    2016-11-03

    Comparison of the ability of newly designed rotary files to eliminate viable Enterococcus faecalis populations from long oval root canals of extracted human teeth to that of the self-adjusting file (SAF). One hundred caries-free, single-rooted, long oval teeth were contaminated with E. faecalis. The teeth were randomly distributed into four groups (n = 25) as follows: G.1, manual; G.2, SAF; G.3, ProTaper Next; and G.4, BT-Race. Two microbial samples were obtained from each tooth with sterile paper points, (s1) before and (s2) after instrumentation. The relative reduction in colony-forming units (CFUs) from s1 to s2 measurements was calculated and compared among the groups using parametric Kruskal-Wallis one-way anova on ranks and Dunn's method (a = 0.05). The results indicated a descending order of the groups with regard to efficacy as follows: BT-Race, Next, SAF and manual. The statistical analysis showed that the relative percentage reduction (RR) of CFUs was lower in the manual group than in the other groups, while the SAF group showed a significantly lower RR than the BT-Race group (P < 0.05). The efficacy in reduction of the microbiological load of viable E. faecalis from long oval root canals was different between the tested endodontic systems.

  18. Scanning electron microscopic evaluation of the influence of manual and mechanical glide path on the surface of nickel-titanium rotary instruments in moderately curved root canals: An in-vivo study

    Science.gov (United States)

    Patel, Dishant; Bashetty, Kusum; Srirekha, A.; Archana, S.; Savitha, B.; Vijay, R.

    2016-01-01

    Aim: The aim of this study was to evaluate the influence of manual versus mechanical glide path (GP) on the surface changes of two different nickel-titanium rotary instruments used during root canal therapy in a moderately curved root canal. Materials and Methods: Sixty systemically healthy controls were selected for the study. Controls were divided randomly into four groups: Group 1: Manual GP followed by RaCe rotary instruments, Group 2: Manual GP followed by HyFlex rotary instruments, Group 3: Mechanical GP followed by RaCe rotary instruments, Group 4: Mechanical GP followed by HyFlex rotary instruments. After access opening, GP was prepared and rotary instruments were used according to manufacturer's instructions. All instruments were evaluated for defects under standard error mean before their use and after a single use. The scorings for the files were given at apical and middle third. Statistical Analysis Used: Chi-squared test was used. Results: The results showed that there is no statistical difference between any of the groups. Irrespective of the GP and rotary files used, more defects were present in the apical third when compared to middle third of the rotary instrument. Conclusion: Within the limitations of this study, it can be concluded that there was no effect of manual or mechanical GP on surface defects of subsequent rotary file system used. PMID:27994317

  19. Sample size considerations for clinical research studies in nuclear cardiology.

    Science.gov (United States)

    Chiuzan, Cody; West, Erin A; Duong, Jimmy; Cheung, Ken Y K; Einstein, Andrew J

    2015-12-01

    Sample size calculation is an important element of research design that investigators need to consider in the planning stage of the study. Funding agencies and research review panels request a power analysis, for example, to determine the minimum number of subjects needed for an experiment to be informative. Calculating the right sample size is crucial to gaining accurate information and ensures that research resources are used efficiently and ethically. The simple question "How many subjects do I need?" does not always have a simple answer. Before calculating the sample size requirements, a researcher must address several aspects, such as purpose of the research (descriptive or comparative), type of samples (one or more groups), and data being collected (continuous or categorical). In this article, we describe some of the most frequent methods for calculating the sample size with examples from nuclear cardiology research, including for t tests, analysis of variance (ANOVA), non-parametric tests, correlation, Chi-squared tests, and survival analysis. For the ease of implementation, several examples are also illustrated via user-friendly free statistical software.

  20. 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.

  1. Effectiveness of ProTaper Universal® and D-RaCe® retreatment files in the removal of root canal filling material: an in vitro study using digital subtraction radiography

    Directory of Open Access Journals (Sweden)

    Caroline Zanesco

    2014-01-01

    Full Text Available Aim: To compare the effectiveness of the ProTaper Universal ® Retreatment system, the D-Race ® NiTi system and Hedströem fi les for removal of fi lling material from curved root canals. Methodology: A total of 39 fi rst mandibular molars were selected and their mesiobuccal (MB canals were used for the study. Teeth were assigned to one of three identical groups (n = 13 per group according to removal technique: G1 – ProTaper Universal ® Retreatment (D1, D2, D3; G2 – D-RaCe ® (DR1, DR2; or G3 – Hedströem fi les (35, 30, 25, 20. In all groups, supplementary fi les were used for re-preparation. Digital subtraction radiography images were produced by superimposing the fi rst radiograph, taken after fi lling the canal, over the second, taking after removal of the fi lling, in buccolingual (BL and mesiodistal (MD projections. Quantitative data were analyzed using intraclass correlation coef fi cients and the Kruskal-Wallis and Friedman non-parametric tests (p ≤ 0.05. Results: Comparison of groups detected no differences in fi lling removal between teeth in the ProTaper Universal ® Retreatment, D-RaCe ® or Hedströem fi le groups for the cervical or mid thirds (for either MD or BL projections. In the apical third (MD projection, ProTaper Universal ® Retreatment produced the best results; and Hedströem fi les exhibited the worst results (MD projection. Intra-group comparisons showed that the cervical third was the cleanest and the apical third was the least well-cleaned, for the ProTaper Universal ® Retreatment and D-RaCe ® groups (MD projection, while less fi lling material was removed using Hedströem when the canals approached the apical third (MD and BL projections. Conclusions: Our fi ndings indicate that the ProTaper Universal ® Retreatment system is the best choice for endodontic fi lling material removal, combined with supplementary instrumentation to achieve better results in the apical third.

  2. 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.

  3. Origin and evolution of the canal raphe system in diatoms.

    Science.gov (United States)

    Ruck, Elizabeth C; Theriot, Edward C

    2011-11-01

    One lineage of pennate diatoms has a slit through the siliceous cell wall, called a "raphe," that functions in motility. Raphid pennate diatoms number in the perhaps tens of thousands of species, with the diversity of raphe forms potentially matching this number. Three lineages-the Bacillariales, Rhopalodiales, and Surirellales-possess a complex and presumably highly derived raphe that is physically separated from the cell interior, most often by a set of siliceous braces. Because the relationship among these three lineages is unclear, the number of origins of the canal raphe system and the homology of it and its constitutive parts among these lineages, is equally unclear. We reconstructed the phylogeny of raphid pennate diatoms and included, for the first time, members of all three canal raphid diatom lineages, and used the phylogeny to test specific hypotheses about the origin of the canal raphe. The canal raphe appears to have evolved twice, once in the common ancestor of Bacillariales and once in the common ancestor of Rhopalodiales and Surirellales, which form a monophyletic group in our analyses. These results recommend careful follow-up morphogenesis studies of the canal raphe in these two lineages to determine the underlying developmental basis for this remarkable case of parallel evolution.

  4. CT and MR Imagings of Semicircular Canal Aplasia

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Chung Hee; Hong, Hyun Sook; Yi, Beom Ha; Cha, Jang Gyu; Park, Seong Jin; Kim, Dae Ho; Lee, Hae Kyung; Kim, Shi Chan [Soonchunhyang University Bucheon Hospital, Bucheon (Korea, Republic of)

    2009-07-15

    To evaluate the clinical, CT and MR imaging findings of semicircular canal (SCC) aplasia and to evaluate if a correlation exists between these findings and the associated anomalies or syndromes. This study retrospectively reviewed the CT and MRI findings of five patients with SCC aplasia. The CT and MR findings were analyzed for SCC, direction of facial nerve canal, cochlea, vestibule, oval or round window, middle ear ossicles, and internal auditory canal (IAC). The subjects included three boys and two girls ranging in age from one to 120 months (mean age; 51 months). Four of the subjects had the CHARGE syndrome, and one had the Goldenhar syndrome. Moreover, four subjects had sensorineural hearing loss and one had combined hearing loss. The course of the facial nerve canal was abnormal in all five cases. Moreover, trapped cochlea and dysplastic modiolus were each observed in one case. Four subjects had atresia of the oval window; whereas ankylosis of the ossicles was present in three subjects. IAC stenosis was present in one patient with the CHARGE syndrome. The aberrant course of the facial nerve canal, atresia of the oval window, and abnormal ossicles were frequently associated in patients with SCC aplasia. In addition, the Goldenhar and CHARGE syndromes were also commonly associated syndromes.

  5. 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.

  6. 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.

  7. Integrating Nuclear Energy to Oilfield Operations – Two Case Studies

    Energy Technology Data Exchange (ETDEWEB)

    Eric P. Robertson; Lee O. Nelson; Michael G. McKellar; Anastasia M. Gandrik; Mike W. Patterson

    2011-11-01

    Fossil fuel resources that require large energy inputs for extraction, such as the Canadian oil sands and the Green River oil shale resource in the western USA, could benefit from the use of nuclear power instead of power generated by natural gas combustion. This paper discusses the technical and economic aspects of integrating nuclear energy with oil sands operations and the development of oil shale resources. A high temperature gas reactor (HTGR) that produces heat in the form of high pressure steam (no electricity production) was selected as the nuclear power source for both fossil fuel resources. Both cases were based on 50,000 bbl/day output. The oil sands case was a steam-assisted, gravity-drainage (SAGD) operation located in the Canadian oil sands belt. The oil shale development was an in-situ oil shale retorting operation located in western Colorado, USA. The technical feasibility of the integrating nuclear power was assessed. The economic feasibility of each case was evaluated using a discounted cash flow, rate of return analysis. Integrating an HTGR to both the SAGD oil sands operation and the oil shale development was found to be technically feasible for both cases. In the oil sands case, integrating an HTGR eliminated natural gas combustion and associated CO2 emissions, although there were still some emissions associated with imported electrical power. In the in situ oil shale case, integrating an HTGR reduced CO2 emissions by 88% and increased natural gas production by 100%. Economic viabilities of both nuclear integrated cases were poorer than the non-nuclear-integrated cases when CO2 emissions were not taxed. However, taxing the CO2 emissions had a significant effect on the economics of the non-nuclear base cases, bringing them in line with the economics of the nuclear-integrated cases. As we move toward limiting CO2 emissions, integrating non-CO2-emitting energy sources to the development of energy-intense fossil fuel resources is becoming

  8. 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.

  9. Functional renormalization group studies of nuclear and neutron matter

    Science.gov (United States)

    Drews, Matthias; Weise, Wolfram

    2017-03-01

    Functional renormalization group (FRG) methods applied to calculations of isospin-symmetric and asymmetric nuclear matter as well as neutron matter are reviewed. The approach is based on a chiral Lagrangian expressed in terms of nucleon and meson degrees of freedom as appropriate for the hadronic phase of QCD with spontaneously broken chiral symmetry. Fluctuations beyond mean-field approximation are treated solving Wetterich's FRG flow equations. Nuclear thermodynamics and the nuclear liquid-gas phase transition are investigated in detail, both in symmetric matter and as a function of the proton fraction in asymmetric matter. The equations of state at zero temperature of symmetric nuclear matter and pure neutron matter are found to be in good agreement with advanced ab-initio many-body computations. Contacts with perturbative many-body approaches (in-medium chiral perturbation theory) are discussed. As an interesting test case, the density dependence of the pion mass in the medium is investigated. The question of chiral symmetry restoration in nuclear and neutron matter is addressed. A stabilization of the phase with spontaneously broken chiral symmetry is found to persist up to high baryon densities once fluctuations beyond mean-field are included. Neutron star matter including beta equilibrium is discussed under the aspect of the constraints imposed by the existence of two-solar-mass neutron stars.

  10. Uncontrolled removal of dentin during in vitro ultrasonic irrigant activation in curved root canals

    NARCIS (Netherlands)

    Retsas, A.; Koursoumis, A.; Tzimpoulas, N.; Boutsioukis, C.

    2016-01-01

    Introduction: The aim of this study was to examine the effect of file type and activation time on the uncontrolled removal of dentin during in vitro ultrasonic irrigant activation in prepared curved root canals. Methods: Seventy-two curved mesial root canals of human mandibular molars were prepared

  11. 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

  12. Effects of Self-Adjusting File, Mtwo, and ProTaper on the root canal wall

    NARCIS (Netherlands)

    Hin, E.S.; Wu, M.K.; Wesselink, P.R.; Shemesh, H.

    2013-01-01

    Introduction The purpose of this ex vivo study was to observe the incidence of cracks in root dentin after root canal preparation with hand files, self-adjusting file (SAF), ProTaper, and Mtwo. Methods One hundred extracted mandibular premolars with single canals were randomly selected. Two angulate

  13. Radiation dose study in nuclear medicine using GATE

    Science.gov (United States)

    Aguwa, Kasarachi

    Dose as a result of radiation exposure is the notion generally used to disclose the imparted energy in a volume of tissue to a potential biological effect. The basic unit defined by the international system of units (SI system) is the radiation absorbed dose, which is expressed as the mean imparted energy in a mass element of the tissue known as "gray" (Gy) or J/kg. The procedure for ascertaining the absorbed dose is complicated since it involves the radiation transport of numerous types of charged particles and coupled photon interactions. The most precise method is to perform a full 3D Monte Carlo simulation of the radiation transport. There are various Monte Carlo toolkits that have tool compartments for dose calculations and measurements. The dose studies in this thesis were performed using the GEANT4 Application for Emission Tomography (GATE) software (Jan et al., 2011) GATE simulation toolkit has been used extensively in the medical imaging community, due to the fact that it uses the full capabilities of GEANT4. It also utilizes an easy to-learn GATE macro language, which is more accessible than learning the GEANT4/C++ programming language. This work combines GATE with digital phantoms generated using the NCAT (NURBS-based cardiac-torso phantom) toolkit (Segars et al., 2004) to allow efficient and effective estimation of 3D radiation dose maps. The GATE simulation tool has developed into a beneficial tool for Monte Carlo simulations involving both radiotherapy and imaging experiments. This work will present an overview of absorbed dose of common radionuclides used in nuclear medicine and serve as a guide to a user who is setting up a GATE simulation for a PET and SPECT study.

  14. A study on the research and development planning of nuclear energy

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Byong Chull; Won, B. C.; Kim, J. W.; Cho, C. Y.; Cheon, S. H.; Kim, J. U.; Kim, I. C.; Hong, Y. P.; Kang, W. J.; Lee, H. S.; Yoon, Y. S.; Park, J. H.; Kim, S. S.; Park, C. S.; Yang, M. S.; Lee, Y. H

    1998-01-01

    This study was performed aiming to provide the basic input to establish `the mild and long-term nuclear R and D program (1997 - 2006)` for government. This program is announced by the government as an official plan after endorsement of Atomic Energy Commission (AEC). Second, the historical formation and transition of both nuclear R and D policy and nuclear R and D development system after the introduction of nuclear energy in Korea were analyzed. Third, the current status of several nuclear-related R and D projects and R and D management, which have been conducted at KAERI were analyzed and a better direction for effective and efficient R and D activities was suggested. Finally, on the basis of above analysis, this study made an effort to extract the appropriate lessons for future directions for carrying out nuclear R and D projects. (author). 19 refs., 40 tabs., 10 figs

  15. 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

  16. Study on evaluation system for Chinese nuclear power plants

    Institute of Scientific and Technical Information of China (English)

    LI Song-bai; CHENG Jian-xiu

    2006-01-01

    This paper analyzes the meaning, structure, function and assessment methods of a nuclear power plant evaluation system, and the similarities and differences among various assessment methods. Based on this research an integrated and detailed suggestion is proposed on how to establish and improve internal and external evaluation systems for Chinese NPPs. It includes: to prepare and implement the nuclear power plant operational management program, to build an integrated performance indicator system, to improve the present audit system and conduct the comprehensive evaluation system, to set up and implement the integrated corrective action system, to position precisely the status of operation assessment of nuclear power plants, to conduct the assessment activities on constructing NPP, to initiate the specific assessment in some important areas, to establish industry performance indicator system, to improve the assessment methods, to share the assessment results, to select,cultivate and certify the reviewers, and to enhance international communication and cooperation.

  17. Dissolution Dynamic Nuclear Polarization capability study with fluid path

    DEFF Research Database (Denmark)

    Malinowski, Ronja Maja; Lipsø, Hans Kasper Wigh; Lerche, Mathilde Hauge

    2016-01-01

    Signal enhancement by hyperpolarization is a way of overcoming the low sensitivity in magnetic resonance; MRI in particular. One of the most well-known methods, dissolution Dynamic Nuclear Polarization, has been used clinically in cancer patients. One way of ensuring a low bioburden of the hyperp......Signal enhancement by hyperpolarization is a way of overcoming the low sensitivity in magnetic resonance; MRI in particular. One of the most well-known methods, dissolution Dynamic Nuclear Polarization, has been used clinically in cancer patients. One way of ensuring a low bioburden...

  18. Poro-elastic modeling of Syringomyelia - a systematic study of the effects of pia mater, central canal, median fissure, white and gray matter on pressure wave propagation and fluid movement within the cervical spinal cord.

    Science.gov (United States)

    Støverud, Karen H; Alnæs, Martin; Langtangen, Hans Petter; Haughton, Victor; Mardal, Kent-André

    2016-01-01

    Syringomyelia, fluid-filled cavities within the spinal cord, occurs frequently in association with a Chiari I malformation and produces some of its most severe neurological symptoms. The exact mechanism causing syringomyelia remains unknown. Since syringomyelia occurs frequently in association with obstructed cerebrospinal fluid (CSF) flow, it has been hypothesized that syrinx formation is mechanically driven. In this study we model the spinal cord tissue either as a poro-elastic medium or as a solid linear elastic medium, and simulate the propagation of pressure waves through an anatomically plausible 3D geometry, with boundary conditions based on in vivo CSF pressure measurements. Then various anatomic and tissue properties are modified, resulting in a total of 11 variations of the model that are compared. The results show that an open segment of the central canal and a stiff pia (relative to the cord) both increase the radial pressure gradients and enhance interstitial fluid flow in the central canal. The anterior median fissure, anisotropic permeability of the white matter, and Poisson ratio play minor roles.

  19. A study on establishing export system of nuclear related equipments to the IAEA

    Energy Technology Data Exchange (ETDEWEB)

    Song, Ki Dong; Lee, Man Ki; Moon, Ki Hwan; Kim, Seung Soo; Lim, Chae Young; Kim, Hwa Sup; Min, Tae Sik [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2002-04-01

    In spite of the advanced status in the international nuclear society, exports of domestic nuclear industries to procurement market of the international organizations has been negligible. This study briefly explained the role and the structure of the IAEA. Then, this study surveyed the size of procurement market, major procurement items, and procurement process. This study also gave an export example to the IAEA from Korea Atomic Energy Research Institute for the ease of understanding the procurement process. Based on these surveys and analysis, this study established the goal and strategy for exports of nuclear equipments to the IAEA. Besides, this study surveyed domestic nuclear industries that have potential to export their products to the IAEA. Then, Korea Atomic Energy Research Institute, by a cooperation with Korea Atomic Industrial Forum Inc., held workshop on 'export of nuclear equipments to IAEA' in May 2001 for them. 4 refs., 1 fig., 10 tabs. (Author)

  20. Spent Nuclear Fuel (SNF) Project Design Basis Capacity Study

    Energy Technology Data Exchange (ETDEWEB)

    CLEVELAND, K.J.

    2000-08-17

    This study of the design basis capacity of process systems was prepared by Fluor Federal Services for the Spent Nuclear Fuel Project. The evaluation uses a summary level model of major process sub-systems to determine the impact of sub-system interactions on the overall time to complete fuel removal operations. The process system model configuration and time cycle estimates developed in the original version of this report have been updated as operating scenario assumptions evolve. The initial document released in Fiscal Year (FY) 1996 varied the number of parallel systems and transport systems over a wide range, estimating a conservative design basis for completing fuel processing in a two year time period. Configurations modeling planned operations were updated in FY 1998 and FY 1999. The FY 1998 Base Case continued to indicate that fuel removal activities at the basins could be completed in slightly over 2 years. Evaluations completed in FY 1999 were based on schedule modifications that delayed the start of KE Basin fuel removal, with respect to the start of KW Basin fuel removal activities, by 12 months. This delay resulted in extending the time to complete all fuel removal activities by 12 months. However, the results indicated that the number of Cold Vacuum Drying (CVD) stations could be reduced from four to three without impacting the projected time to complete fuel removal activities. This update of the design basis capacity evaluation, performed for FY 2000, evaluates a fuel removal scenario that delays the start of KE Basin activities such that staffing peaks are minimized. The number of CVD stations included in all cases for the FY 2000 evaluation is reduced from three to two, since the scenario schedule results in minimal time periods of simultaneous fuel removal from both basins. The FY 2000 evaluation also considers removal of Shippingport fuel from T Plant storage and transfer to the Canister Storage Building for storage.

  1. Radiation damage studies related to nuclear waste forms

    Energy Technology Data Exchange (ETDEWEB)

    Gray, W.J.; Wald, J.W.; Turcotte, R.P.

    1981-12-01

    Much of the previously reported work on alpha radiation effects on crystalline phases of importance to nuclear waste forms has been derived from radiation effects studies of composite waste forms. In the present work, two single-phase crystalline materials, Gd/sub 2/Ti/sub 2/O/sub 7/ (pyrochlore) and CaZrTi/sub 2/O/sub 7/ (zirconolite), of relative importance to current waste forms were studied independently by doping with /sup 244/Cm at the 3 wt % level. Changes in the crystalline structure measured by x-ray diffraction as a function of dose show that damage ingrowth follows an expected exponential relationship of the form ..delta..V/V/sub 0/ = A(1-exp(-BD)). In both cases, the materials became x-ray amorphous before the estimated saturation value was reached. The predicted magnitudes of the unit cell volume changes at saturation are 5.4% and 3.5%, respectively, for Gd/sub 2/Ti/sub 2/O/sub 7/ and CaZrTi/sub 2/O/sub 7/. The later material exhibited anisotropic behavior in which the expansion of the monoclinic cell in the c/sub 0/ direction was over five times that of the a/sub 0/ direction. The effects of transmutations on the properties of high-level waste solids have not been studied until now because of the long half-lives of the important fission products. This problem was circumvented in the present study by preparing materials containing natural cesium and then irradiating them with neutrons to produce /sup 134/Cs, which has only a 2y half-life. The properties monitored at about one year intervals following irradiation have been density, leach rate and microstructure. A small amount of x-ray diffraction work has also been done. Small changes in density and leach rate have been observed for some of the materials, but they were not large enough to be of any consequence for the final disposal of high level wastes.

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

    OpenAIRE

    Fabrício SCAINI; Fabio Leal BRAGA; Irdival Cristino FIGUEIREDO JÚNIOR; Rafael Brandão FERREIRA; Baratto Filho,Flares; de SOUSA NETO, Manoel Damião

    2005-01-01

    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 cas...

  3. Evaluation of pre-fabricated root canal posts.

    Science.gov (United States)

    Hew, Y S; Purton, D G; Love, R M

    2001-03-01

    In this in vitro study, properties of a titanium alloy post recently introduced to the market (IntegraPost), were compared with those of a clinically proven stainless steel post (ParaPost). The IntegraPost has a unique, perforated, spherical head and a microknurled shank surface. The posts were tested for rigidity, for retention within the root canals of extracted teeth and for ability to retain composite resin cores. The two post types exhibited similar properties in core and root canal retention, however, the IntegraPost was significantly less rigid than the ParaPost.

  4. 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.

  5. 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.)

  6. A study on emergency preparedness for nuclear power plant/ Establishment of emergency communication network system

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Y. K.; Jung, Y. D.; Kim, S. Y. [Korea Institute of Science and Technology, Seoul (Korea, Republic of)

    1991-12-15

    The objective of this study was to develop an emergency database search system for nuclear power plants during nuclear incidents / accidents. Image data reported from nuclear power plants to the regulatory body and other related data will be stored systematically in the computer. The data will be utilized during nuclear emergency to prevent the accident from spreading out and to minimize its effect. It will also be used in exchanging information on accident or incidents with the foreign countries. The operational documents in the Kori-4 nuclear power plant are used as the major source for the categorization and analysis in performing this research. It was not easy to access the detailed operational data due to its unique characteric for the security. Therefore, we strongly suggest to increase manpower for this project in Korea Institute of Nuclear Safety (KINS) and archive involvement from Korea Electric Power Company to establish better database retrieval system.

  7. A brief history of design studies on innovative nuclear reactors

    Energy Technology Data Exchange (ETDEWEB)

    Sekimoto, Hiroshi, E-mail: hsekimot@gmail.com [Emeritus Professor, Tokyo Institute of Technology (Japan)

    2014-09-30

    In a short period after the success of CP1, many types of nuclear reactors were proposed and investigated. However, soon only a small number of reactors were selected for practical use. Around 1970, only LWRs with small number of CANDUs were operated in the western world, and FBRs were under development. It was about the time when Apollo moon landing was accomplished. However, at the same time, the future of human being was widely considered pessimistic and Limits to Growth was published. In the end of 1970’s the TMI accident occurred and many nuclear reactor contracts were cancelled in USA and any more contracts had not been concluded until recent years. From the reflection of this accident, many Inherent Safe Reactors (ISRs) were proposed, though none of them were constructed. A common idea of ISRs is smallness of their size. Tokyo Institute of Technology (TokyoTech) held a symposium on small reactors, SR/TIT, in 1991, where many types of small ISRs were presented. Recently small reactors attract interest again. The most ideas employed in these reactors were the same discussed in SR/TIT. In 1980’s the radioactive wastes from fuel cycle became a severe problem around the world. In TokyoTech, this issue was discussed mainly from the viewpoint of nuclear transmutations. The neutron economy became inevitable for these innovative nuclear reactors especially small long-life reactors and transmutation reactors.

  8. Neutron studies of nuclear magnetism at ultralow temperature

    DEFF Research Database (Denmark)

    Siemensmeyer, K.; Clausen, K.N.; Lefmann, K.

    1998-01-01

    Nuclear magnetic order in copper and silver has been investigated by neutron diffraction. Antiferromagnetic order is observed in these simple, diamagnetic metals at temperatures below 50 nK and 560 pK, respectively. Both crystallize in the FCC-symmetry which is fully frustrated for nearest...

  9. A brief history of design studies on innovative nuclear reactors

    Science.gov (United States)

    Sekimoto, Hiroshi

    2014-09-01

    In a short period after the success of CP1, many types of nuclear reactors were proposed and investigated. However, soon only a small number of reactors were selected for practical use. Around 1970, only LWRs with small number of CANDUs were operated in the western world, and FBRs were under development. It was about the time when Apollo moon landing was accomplished. However, at the same time, the future of human being was widely considered pessimistic and Limits to Growth was published. In the end of 1970's the TMI accident occurred and many nuclear reactor contracts were cancelled in USA and any more contracts had not been concluded until recent years. From the reflection of this accident, many Inherent Safe Reactors (ISRs) were proposed, though none of them were constructed. A common idea of ISRs is smallness of their size. Tokyo Institute of Technology (TokyoTech) held a symposium on small reactors, SR/TIT, in 1991, where many types of small ISRs were presented. Recently small reactors attract interest again. The most ideas employed in these reactors were the same discussed in SR/TIT. In 1980's the radioactive wastes from fuel cycle became a severe problem around the world. In TokyoTech, this issue was discussed mainly from the viewpoint of nuclear transmutations. The neutron economy became inevitable for these innovative nuclear reactors especially small long-life reactors and transmutation reactors.

  10. Nuclear astrophysics studies by SAMURAI spectrometer in RIKEN RIBF

    Science.gov (United States)

    Yoneda, K.

    2012-11-01

    SAMURAI is a spectrometer which is now being constructed at RIKEN RI Beam Factory. This spectrometer is characterized by a large angular-and momentum-acceptance enabling, for example, multi-particle coincidence measurements. Here brief descriptions of SAMURAI spectrometer and physics topics relevant to nuclear astrophysics are presented.

  11. Nuclear astrophysics studies by SAMURAI spectrometer in RIKEN RIBF

    Energy Technology Data Exchange (ETDEWEB)

    Yoneda, K. [RIKEN Nishina Center, 2-1, Hirosawa, Wako, Saitama 351-0198 (Japan)

    2012-11-12

    SAMURAI is a spectrometer which is now being constructed at RIKEN RI Beam Factory. This spectrometer is characterized by a large angular-and momentum-acceptance enabling, for example, multi-particle coincidence measurements. Here brief descriptions of SAMURAI spectrometer and physics topics relevant to nuclear astrophysics are presented.

  12. 三种根管预备器械预备根管根尖碎屑推出量和根管清理能力的比较%Self-adjusting files, ProTaper Next and ProTaper Universal:a comparative study of root canal cleanness and the amount of apically extruded debris during root canal preparation

    Institute of Scientific and Technical Information of China (English)

    伍婉翠; 陈广盛

    2015-01-01

    BACKGROUND:Amount of debris extruded apicaly is an important indicator to evaluate the effect of root canal preparation instrument. Studies have shown that debris extruded apicaly can cause post-treatment pain, and thus, reducing the amount of debris extruded apicaly can decrease the incidence of post-treatment pain. OBJECTIVE:To compare the root canal cleanness and the amount of apicaly extruded debris during root canal preparation with Self-adjusting files, ProTaper Next and ProTaper Universal. METHODS:Forty-five premolars with single canal were divided into three groups randomly, and then prepared by Self-adjusting files, ProTaper Next and ProTaper Universal, respectively. Debris extruded apicaly was colected, dried and weighed. Then roots were longitudinaly sectioned and observed under scanning electronic microscope to evaluate the cleanness of the root canal. RESULTS AND CONCLUSION:The amount of apicaly extruded debris in the ProTaper Universal group was significantly higher than that in the Self-adjusting files group and ProTaper Next group (P 0.05). Scores on debris and smear layer were lower in the group of Self-adjusting files than the groups of ProTaper Next and ProTaper Universal (P 0.05). These findings indicate that the Self-adjusting files and ProTaper Next can extrude less debris beyond the apical foramen, which may decrease the incidence of post-treatment pain. Cleaning ability of Self-adjusting files is better than ProTaper Next and ProTaper Universal.%背景:根尖碎屑推出量是评价根管预备器械预备效果的一项重要指标。研究表明,推出根尖孔的碎屑将引起根管治疗后疼痛,减少根尖区碎屑的推出可降低术后疼痛发生率。目的:比较新型镍钛器械自调节根管锉、ProTaper Next和传统镍钛器械ProTaper Universal预备人下颌单根管前磨牙的根尖碎屑推出量和根管清理能力。方法:将45颗离体人下颌单根管前磨牙随机均分为3组,分别使用新

  13. Morphology of the mandibular canal and the angulation between the mandibular and mental canals in dry skulls

    DEFF Research Database (Denmark)

    Pálsson, S R; Kjaer, I

    2008-01-01

    The aim of this study was to analyse the correlation between external and internal mandibular morphology in adult or adolescent normal anthropological mandibles. Lateral radiographs of 31 symmetrical mandibles were analysed. The external morphology was defined by the gonial and beta......-angles. In order to analyse internal morphology, a metallic pin was placed in the mental canal on the left side before radiography. The angle between the mental and the mandibular canals was termed the 'mental angle' and that expressing the curvature of the mandibular canal, the 'mandibular angle'. Spearman...... correlation analysis was used to investigate the relationships between the angles. Internal morphology: a statistically significant correlation was found between the mental and mandibular angles (correlation coefficient: -0.60, P=0.0004). When the mental angle was narrow, the mandibular angle tended...

  14. Stability of guest molecules in urea canal complexes by canal polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Yoshii, Fumio; Makuuchi, Keizo [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    1995-03-01

    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).

  15. Canals, DMADCanals-Irrigation canals in Millard Co., Published in 2007, Millard County.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Canals dataset, was produced all or in part from Other information as of 2007. It is described as 'DMADCanals-Irrigation canals in Millard Co.'. Data by this...

  16. MRI Findings in Spinal Canal Stenosis

    OpenAIRE

    Maryam Barzin

    2010-01-01

    Spinal canal stenosis results from progressive narrowing of the central spinal canal and the lateral recesses. Primary (congenital) lumbar spinal stenosis is associated with achondroplastic dwarfism. The spinal canal may become narrowed by bulging or protrusion of the intervertebral disc annulus, herniation of the nucleus pulposus posteriorly, thickening of the posterior longitudinal ligament, hypertrophy of the facet joints, hypertrophy of the ligamentum flavum, epidural fat deposition, spon...

  17. Comparative morphology of stingray lateral line canal and electrosensory systems.

    Science.gov (United States)

    Jordan, Laura K

    2008-11-01

    Elasmobranchs (sharks, skates, and rays) possess a variety of sensory systems including the mechanosensory lateral line and electrosensory systems, which are particularly complex with high levels of interspecific variation in batoids (skates and rays). Rays have dorsoventrally compressed, laterally expanded bodies that prevent them from seeing their mouths and more often than not, their prey. This study uses quantitative image analysis techniques to identify, quantify, and compare structural differences that may have functional consequences in the detection capabilities of three Eastern Pacific stingray species. The benthic round stingray, Urobatis halleri, pelagic stingray, Pteroplatytrygon (Dasyatis) violacea, and benthopelagic bat ray, Myliobatis californica, show significant differences in sensory morphology. Ventral lateral line canals correlate with feeding ecology and differ primarily in the proportion of pored and nonpored canals and the degree of branching complexity. Urobatis halleri shows a high proportion of nonpored canals, while P. violacea has an intermediate proportion of pored and nonpored canals with almost no secondary branching of pored canals. In contrast, M. californica has extensive and highly branched pored ventral lateral line canals that extended laterally toward the wing tips on the anterior edge of the pectoral fins. Electrosensory morphology correlates with feeding habitat and prey mobility; benthic feeders U. halleri and M. californica, have greater electrosensory pore numbers and densities than P. violacea. The percentage of the wing surface covered by these sensory systems appears to be inversely related to swimming style. These methods can be applied to a broader range of species to enable further discussion of the relationship of phylogeny, ecology, and morphology, while the results provide testable predictions of detection capabilities.

  18. How the cross-sectional discontinuity between ear canal and probe affects the ear canal length estimation.

    Science.gov (United States)

    Zebian, Makram; Hensel, Johannes; Fedtke, Thomas

    2012-07-01

    Many ear canal probes both deliver and measure sound via narrow tubes. This study investigates the effect of the cross-sectional discontinuity at the interface between ear canal models and the connecting tubes of a commercially available otoacoustic emission probe on the "acoustically" estimated cavity lengths. Rigid cavities having the same length but different diameters were produced, and modeled by the finite element method. Cavities with a diameter larger than 8 mm had acoustic lengths that considerably overestimated the real geometry. A length correction was derived, which, in most applications, compensates for the measurement errors emerging from the discontinuity effects.

  19. Shape and Deformation Analysis of the Human Ear Canal

    DEFF Research Database (Denmark)

    Darkner, Sune

    This thesis presents work on the analysis of the dynamic behavior of the human ear canal. The work is based on two studies designed during the project, a pilot study with 30 normal hearing subjects and a main study with 42 hearing impaired subjects, all hearing-aid users. The main focus is on the......This thesis presents work on the analysis of the dynamic behavior of the human ear canal. The work is based on two studies designed during the project, a pilot study with 30 normal hearing subjects and a main study with 42 hearing impaired subjects, all hearing-aid users. The main focus...... is on the extraction and analysis of the shape and deformation of the ear canal due to movements of the mandible, leaning over, and turning of the head. Methods for surface registration with focus on non-rigid registration are presented, as well as a wide range of statistical methods used for analyzing the shapes...... and deformation fields. The results show that the ear canal changes shape significantly in all subjects and that the deformation is more complicated than previously described in the literature. It is shown that the deformation at specific locations in the ear is significantly correlated to comfort issues reported...

  20. The adult macaque spinal cord central canal zone contains proliferative cells and closely resembles the human.

    Science.gov (United States)

    Alfaro-Cervello, Clara; Cebrian-Silla, Arantxa; Soriano-Navarro, Mario; Garcia-Tarraga, Patricia; Matías-Guiu, Jorge; Gomez-Pinedo, Ulises; Molina Aguilar, Pilar; Alvarez-Buylla, Arturo; Luquin, Maria-Rosario; Garcia-Verdugo, Jose Manuel

    2014-06-01

    The persistence of proliferative cells, which could correspond to progenitor populations or potential cells of origin for tumors, has been extensively studied in the adult mammalian forebrain, including human and nonhuman primates. Proliferating cells have been found along the entire ventricular system, including around the central canal, of rodents, but little is known about the primate spinal cord. Here we describe the central canal cellular composition of the Old World primate Macaca fascicularis via scanning and transmission electron microscopy and immunohistochemistry and identify central canal proliferating cells with Ki67 and newly generated cells with bromodeoxyuridine incorporation 3 months after the injection. The central canal is composed of uniciliated, biciliated, and multiciliated ependymal cells, astrocytes, and neurons. Multiciliated ependymal cells show morphological characteristics similar to multiciliated ependymal cells from the lateral ventricles, and uniciliated and biciliated ependymal cells display cilia with large, star-shaped basal bodies, similar to the Ecc cells described for the rodent central canal. Here we show that ependymal cells with one or two cilia, but not multiciliated ependymal cells, proliferate and give rise to new ependymal cells that presumably remain in the macaque central canal. We found that the infant and adult human spinal cord contains ependymal cell types that resemble those present in the macaque. Interestingly, a wide hypocellular layer formed by bundles of intermediate filaments surrounded the central canal both in the monkey and in the human, being more prominent in the stenosed adult human central canal.

  1. Response of selenium concentrations in groundwater to seasonal canal leakage, lower Gunnison River Basin, Colorado, 2013

    Science.gov (United States)

    Linard, J.I.; McMahon, P.B.; Arnold, L.R.; Thomas, J.C.

    2016-05-23

    Selenium is a water-quality concern in the lower Gunnison River Basin because irrigation water interacting with seleniferous soils derived from the Mancos Shale Formation has mobilized selenium and increased its concentrations in surface water. Understanding the occurrence of elevated selenium concentrations in groundwater is necessary because groundwater discharge is an important source of selenium in surface water in the basin. In 2013, the U.S. Geological Survey, in cooperation with the Bureau of Reclamation and the Colorado Water Conservation Board, began a study to understand how changes in groundwater levels attributed to canal leakage affected the concentrations and speciation of dissolved selenium in groundwater. The purpose of this report is to characterize the groundwater adjacent to an unlined leaky canal. Two locations, near the East Canal (W-N1 and W-N2) and farther from the East Canal (W-M1 and W-M2), were selected for nested monitoring well installations. The pressure exerted by changes in canal stage was more readily transferred to the deep groundwater measured in the W-N1 near the canal than the shallow groundwater at the W-N2 well. No definitive relation could be made between canal water-level elevation and water-level elevations in monitoring wells farther from the canal (W-M1 and W-M2). 

  2. Yard flooding by irrigation canals increased the risk of West Nile disease in El Paso, Texas

    Science.gov (United States)

    Cardenas, Victor M.; Jaime, Javier; Ford, Paula B.; Gonzalez, Fernando J.; Carrillo, Irma; Gallegos, Jorge E.; Watts, Douglas M.

    2011-01-01

    Purpose To investigate the effects of use of water from irrigation canals to flood residential yards on the risk of West Nile disease in El Paso, Texas. Methods West Nile disease confirmed cases in 2009–2010 were compared with a random sample of 50 residents of the county according to access to and use of water from irrigation canals by subjects or their neighbors, as well as geo-referenced closest distance between their home address and the nearest irrigation canal. A windshield survey of 600 meters around the study subjects’ home address recorded the presence of irrigation canals. The distance from the residence of 182 confirmed cases of West Nile disease reported in 2003–2010 to canals was compared to that of the centroids of 182 blocks selected at random. Results Cases were more likely than controls to report their neighbors flooded their yards with water from canals. Irrigation canals were more often observed in neighborhoods of cases than of controls. Using the set of addresses of 182 confirmed cases and 182 hypothetic controls the authors found a statistically significant inverse relation with risk of West Nile disease. Conclusions Flooding of yards with water from canals increased the risk of West Nile disease. PMID:21943648

  3. Dynamic intratubular biomineralization following root canal obturation with pozzolan‐based mineral trioxide aggregate sealer cement

    Science.gov (United States)

    Yoo, Yeon‐Jee; Baek, Seung‐Ho; Kum, Kee‐Yeon; Shon, Won‐Jun; Woo, Kyung‐Mi

    2015-01-01

    Summary The application of mineral trioxide aggregates (MTA) cement during the root canal obturation is gaining concern due to its bioactive characteristic to form an apatite in dentinal tubules. In this regard, this study was to assess the biomineralization of dentinal tubules following root canal obturation by using pozzolan‐based (Pz‐) MTA sealer cement (EndoSeal MTA, Maruchi). Sixty curved roots (mesiobuccal, distobuccal) from human maxillary molars were instrumented and prepared for root canal obturation. The canals were obturated with gutta‐percha (GP) and Pz‐MTA sealer by using continuous wave of condensation technique. Canals obturated solely with ProRoot MTA (Dentsply Tulsa Dental) or Pz‐MTA sealer were used for comparison. In order to evaluate the biomineralization ability under different conditions, the PBS pretreatment before the root canal obturation was performed in each additional samples. At dentin‐material interfaces, the extension of intratubular biomineralization was analyzed using scanning electron microscopy (SEM) and energy dispersive spectroscopy. When the root canal was obturated with GP and Pz‐MTA sealer, enhanced biomineralization of the dentinal tubules beyond the penetrated sealer tag was confirmed under the SEM observation (p cement can be used as a promising bioactive root canal sealer to enhance biomineralization of dentinal tubules under controlled environment. SCANNING 38:50–56, 2016. © 2015 The Authors. Scanning Published by Wiley Periodicals, Inc. PMID:26179659

  4. Dynamic intratubular biomineralization following root canal obturation with pozzolan-based mineral trioxide aggregate sealer cement.

    Science.gov (United States)

    Yoo, Yeon-Jee; Baek, Seung-Ho; Kum, Kee-Yeon; Shon, Won-Jun; Woo, Kyung-Mi; Lee, WooCheol

    2016-01-01

    The application of mineral trioxide aggregates (MTA) cement during the root canal obturation is gaining concern due to its bioactive characteristic to form an apatite in dentinal tubules. In this regard, this study was to assess the biomineralization of dentinal tubules following root canal obturation by using pozzolan-based (Pz-) MTA sealer cement (EndoSeal MTA, Maruchi). Sixty curved roots (mesiobuccal, distobuccal) from human maxillary molars were instrumented and prepared for root canal obturation. The canals were obturated with gutta-percha (GP) and Pz-MTA sealer by using continuous wave of condensation technique. Canals obturated solely with ProRoot MTA (Dentsply Tulsa Dental) or Pz-MTA sealer were used for comparison. In order to evaluate the biomineralization ability under different conditions, the PBS pretreatment before the root canal obturation was performed in each additional samples. At dentin-material interfaces, the extension of intratubular biomineralization was analyzed using scanning electron microscopy (SEM) and energy dispersive spectroscopy. When the root canal was obturated with GP and Pz-MTA sealer, enhanced biomineralization of the dentinal tubules beyond the penetrated sealer tag was confirmed under the SEM observation (p cement can be used as a promising bioactive root canal sealer to enhance biomineralization of dentinal tubules under controlled environment.

  5. Feasibility Study on the Development of Index that Shows Social and Cultural Acceptance of Nuclear Power

    Energy Technology Data Exchange (ETDEWEB)

    Cho, SeongKyung [Bangmok College of General Education at Myongji Univ., Yongin (Korea, Republic of); Choi, Seungho; Yoon, Hana; Song, Jiyeon [Domo Brodeur, Seoul (Korea, Republic of)

    2015-05-15

    In this context, it is necessary to manage and develop an index that can measure the level of public acceptance by establishing the terms of social/cultural public acceptance of nuclear power in a practical manner and by identifying influential factors of public acceptance. Developing an index itself is not intended to increase the public acceptance of nuclear power. This study intends to contribute to determining energy policy acceptable to the public by estimating the level of potential social conflicts related to nuclear power policies with eligible evaluation criteria on social/cultural acceptance and by reducing relevant social costs. Key conclusions and proposal of this research are as follows. First, the influential factors of acceptance are reliability of nuclear safety, risk perception of nuclear power and beneficial perception of nuclear power. Among them, reliability of nuclear safety appears to have the most influence. In addition, benefit perception of nuclear power at the social level is significantly higher than that at the individual level. However, in relation to risk perception, a gap between experts and the public is found as nuclear industry premises that accident does not occur while the public premises that accident may occur.

  6. Study on international publicity and export strategy establishment of nuclear technology

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ji Bok; Choi, C.O.; Park, K. B.; Chang, M. H.; Kim, K. K.; Yang, M. S.; Jung, I. H.; Kim, K. P.; Wu, J. S.; Jang, C. I.; Han, B. O.; Sim, J. H.; Chung, M.; Chung, J.K

    1999-05-01

    The objective of this study is to devise a proper measure for international publicity and technology export strategy. Analysed and summaries in detail are other countries nuclear policy trend and the current technology development status of Korea Standard Nuclear Plant that we developed on our own technology, design and construction technology for research reactor, System-integrated Modular Advanced Reactor of which design is in progress, Direct use of Spent PWR Fuel in CANDU Reactors, and Radioisotopes. Based on that, the measures are proposed for the export industrialization of nuclear technology and establishment of the export basis. Also the international nuclear cooperation and publicity strategy are suggested to support the technology export basis. By surveying the world nuclear status, the direction for the international cooperation and publicity is settled and the specific publicity strategy is proposed for the cooperation with IAEA and multi-countries and the establishment of the nuclear technology export basis. As part of this project, the panel on major technologies such as Korea Standard Nuclear Plant, HANARO, and System-integrated Modular Advanced Reactor was displayed successfully at the IAEA meeting, which contribute much to the publicity of our nuclear technology to the international nuclear society. (author)

  7. 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.)

  8. Nuclear magnetic and quadrupole resonance studies of the stripes materials

    Energy Technology Data Exchange (ETDEWEB)

    Grafe, H.-J., E-mail: h.grafe@ifw-dresden.de [IFW Dresden, Institute for Solid State Research, P.O. Box 270116, D-01171 Dresden (Germany)

    2012-11-01

    Nuclear Magnetic and Quadrupole Resonance (NMR/NQR) is a powerful tool to probe electronic inhomogeneities in correlated electron systems. Its local character allows for probing different environments due to spin density modulations or inhomogeneous doping distributions emerging from the correlations in these systems. In fact, NMR/NQR is not only sensitive to magnetic properties through interaction of the nuclear spin, but also allows to probe the symmetry of the charge distribution and its homogeneity, as well as structural modulations, through sensitivity to the electric field gradient (EFG). We review the results of NMR and NQR in the cuprates from intrinsic spatial variations of the hole concentration in the normal state to stripe order at low temperatures, thereby keeping in mind the influence of doping induced disorder and inhomogeneities. Finally, we briefly discuss NQR evidence for local electronic inhomogeneities in the recently discovered iron pnictides, suggesting that electronic inhomogeneities are a common feature of correlated electron systems.

  9. Comparative nuclear effects of biomedical interest. Civil effects study

    Energy Technology Data Exchange (ETDEWEB)

    White, C.S.; Bowen, I.G.; Richmond, D.R.; Corsbie, R.L.

    1961-01-12

    Selected physical and biological data bearing upon the environmental variations created by nuclear explosions are presented in simplified form. Emphasis is placed upon the ``early`` consequences of exposure to blast, thermal radiation, and ionizing radiation to elucidate the comparative ranges of the major effects as they vary with explosive yield and as they contribute to the total hazard to man. A section containing brief definitions of the terminology employed is followed by a section that utilizes text and tabular material to set forth events that follow nuclear explosions and the varied responses of exposed physical and biological materials. Finally, selected quantitative weapons-effects data in graphic and tabular form are presented over a wide range of explosive yields to show the relative distances from Ground Zero affected by significant levels of blast overpressures, thermal fluxes, and initial and residual penetrating ionizing radiations. However, only the ``early`` rather than the ``late`` effects of the latter are considered.

  10. Study of heuristics in ant system for nuclear reload optimisation

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Alan M.M. de; Schirru, Roberto; Silva, Fernando C. da; Machado, Marcelo D.; Medeiros, Jose A.C.C. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Programa de Engenharia Nuclear]. E-mail: alan@lmp.ufrj.br; schirru@lmp.ufrj.br; fernando@con.ufrj.br; marcelo@lmp.ufrj.br; canedo@lmp.ufrj.br

    2007-07-01

    A Pressurized Water Reactor core must be reloaded every time the fuel burnup reaches a level when it is not possible to sustain nominal power operation. The nuclear core fuel reload optimization consists in finding a burned-up and fresh-fuel-assembly loading pattern that maximizes the number of effective full power days, minimizing the relationship cost/benefit. This problem is NP-hard, meaning that complexity grows exponentially with the number of fuel assemblies in the core. Besides that, the problem is non-linear and its search space is highly discontinual and multimodal. In this work a parallel computational system based on Ant Colony System (ACS) called Artificial-Ant-Colony Networks is used to solve the nuclear reactor core fuel reload optimization problem, with compatibles heuristics. ACS is a system based on artificial agents that uses the reinforcement learning technique and was originally developed to solve the Traveling Salesman Problem, which is conceptually similar to the nuclear fuel reload problem. (author)

  11. Interactions between root canal irrigants, sealers and dentin

    NARCIS (Netherlands)

    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 res

  12. Mimamata and Love Canal: A Pollution Tale of Two Cities.

    Science.gov (United States)

    Williams, Mary Louise

    1993-01-01

    Presents a lesson plan about case studies of the environmental disasters of Minamata, Japan and Love Canal, New York. Compares how the legal cases were handled in two constitutional democracies. Provides six handouts that include maps, role descriptions for simulations, and student readings. (CFR)

  13. Narrow, duplicated internal auditory canal

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, T. [Servico de Neurorradiologia, Hospital Garcia de Orta, Avenida Torrado da Silva, 2801-951, Almada (Portugal); Shayestehfar, B. [Department of Radiology, UCLA Oliveview School of Medicine, Los Angeles, California (United States); Lufkin, R. [Department of Radiology, UCLA School of Medicine, Los Angeles, California (United States)

    2003-05-01

    A narrow internal auditory canal (IAC) constitutes a relative contraindication to cochlear implantation because it is associated with aplasia or hypoplasia of the vestibulocochlear nerve or its cochlear branch. We report an unusual case of a narrow, duplicated IAC, divided by a bony septum into a superior relatively large portion and an inferior stenotic portion, in which we could identify only the facial nerve. This case adds support to the association between a narrow IAC and aplasia or hypoplasia of the vestibulocochlear nerve. The normal facial nerve argues against the hypothesis that the narrow IAC is the result of a primary bony defect which inhibits the growth of the vestibulocochlear nerve. (orig.)

  14. Relationship between lower third molar and mandibular canal; Preoperative evaluation using CT scan

    Energy Technology Data Exchange (ETDEWEB)

    Itou, Masaki; Miyagishima, Toshio; Onizuka, Hiroyuki (Fujieda City Shida General Hospital, Shizuoka (Japan)); Takagi, Norio

    1994-01-01

    The mandibular canal is often closely related to the lower third molars. During the surgical removal of the third molar, the inferior alveolar nerve in the canal is sometimes damaged leading to impaired sensation in the lower lip. This is one of the most unpleasant postoperative complications. The buccolingual relationship between the lower third molar and the mandibular canal cannot be diagnosed by ortho-pantomography although preoperative evaluation must be carried out radiologically. In present study, the relationship was determined by using CT scan. Forty-seven lower third molars of 35 patients were evaluated preoperatively by CT scan. The mandibular canal of all cases overlapped with the third molar on ortho-pantomography. CT scan was taken in two ways. The first was the Tragion-Menton plane which was nearly parallel to the canal at the apex of the third molar. The second was the plane of the axis of the third molar. Axial CT scan was taken when the third molar erupted horizontally, and coronal CT scan was done when the molar erupted vertically. CT scan examination exactly revealed the position of the mandibular canal in relation to the root of the third molar. The canal was located buccally to the roots in 55 percent of cases, apicobuccally in 6 percent, apically in 23 percent, apicolingually in 6 percent, lingually in 2 percent, and between roots in 6 percent. The results of the present study were consistent with previous reports. In 12 cases, the inferior alveolar neurovascular bundle was visible during operation. It was visible in only 2 of 22 cases when the canal was located buccally. It was visible, on the other hand, in all cases in which the canal was located apicolingually, lingually, and between roots. It also tended to be visible when the canal overlapped more strongly with the third molar on preoperative ortho-pantomography. (author).

  15. Studies on spent nuclear fuel evolution during storage

    Energy Technology Data Exchange (ETDEWEB)

    Rondinella, V.V.; Wiss, T.A.G.; Papaioannou, D.; Nasyrow, R. [European Commission Joint Research Centre, Karlsruhe (Germany). Inst. for Transuranium Elements

    2015-07-01

    Initially conceived to last only a few decades (40 years in Germany), extended storage periods have now to be considered for spent nuclear fuel due to the expanding timeline for the definition and implementation of the disposal in geologic repository. In some countries, extended storage may encompass a timeframe of the order of centuries. The safety assessment of extended storage requires predicting the behavior of the spent fuel assemblies and the package systems over a correspondingly long timescale, to ensure that the mechanical integrity and the required level of functionality of all components of the containment system are retained. Since no measurement of ''old'' fuel can cover the ageing time of interest, spent fuel characterization must be complemented by studies targeting specific mechanisms that may affect properties and behavior of spent fuel during extended storage. Tests conducted under accelerated ageing conditions and other relevant simulations are useful for this purpose. During storage, radioactive decay determines the overall conditions of spent fuel and generates heat that must be dissipated. Alpha-decay damage and helium accumulation are key processes affecting the evolution of properties and behavior of spent fuel. The radiation damage induced by a decay event during storage is significantly lower than that caused by a fission during in-pile operation: however, the duration of the storage is much longer and the temperature levels are different. Another factor potentially affecting the mechanical integrity of spent fuel rods during storage and handling / transportation is the behavior of hydrogen present in the cladding. At the Institute for Transuranium Elements, part of the Joint Research Centre of the European Commission, spent fuel alterations as a function of time and activity are monitored at different scales, from the microstructural level (defects and lattice parameter swelling) up to macroscopic properties such as

  16. Classifications of mandibular canal branching:A review of literature

    Institute of Scientific and Technical Information of China (English)

    Mauricio Augusto Aquino Castro; Manuel Oscar Lagravere-Vich; Tania Mara Pimenta Amaral; Mauro Henrique Guimaraes Abreu; Ricardo Alves Mesquita

    2015-01-01

    AIM: To gather existing radiographic classifications of mandibular canals branching, considering the criteria on which these were based.METHODS: The search for studies on mandibular canals based on imaging exams included literature reviews, epidemiological studies of prevalence, descriptive studies, or case reports. An electronic search in the MEDLINE(Ovid SP), Pub Med, EMBASE(Ovid SP), Web of Science(Thompson Reuters), and Scopus(Elsevier) databases was performed, as well as a manual evaluation of the references of the selected articles. Combinations of key words were placed in each database. No restrictions were imposed regarding the year of publication or language. References collected in duplicate were removed by the authors. A table was drawn up, containing the included studies and respective interest data.RESULTS: Six classifications of mandibular canals branching were selected for the present literature review. Four were based on two-dimensional radiographic exams, and two were performed based on threedimensional tomographic exams. Three-dimensional classifications were determined based on the analysis found in the least number of exams, comparatively to two-dimensional studies. The prevalence of mandibular canal branching varied from 0% to 38.75% in the works based on two-dimensional exams, while those found inthree-dimensional exams ranged from 15.6% to 65%. The studies were mostly referred to branches that began in the mandibular ramus. Just one classification considered the branches that began in the mandibular body region.CONCLUSION: Three-dimensional exams appear to be the best method to view mandibular canal branching. Further studies are warranted to determine its true prevalence and questions concerning to associations.

  17. A study on the planning for the research and development of nuclear energy

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Byong Chull; Won, B. C.; Bang, J. K.; Jung, Y. H.; Kim, M. R.; Cho, C. Y.; Lee, H. S.; Kim, J. U.; Yeo, J. W.; Hong, Y. P.; Kim, I. C.; Rha, K. H.; Yoon, Y. S.; Park, J. H.; Ko, Y. S.; Kim, S. S.; Kang, W. J.; Lee, Y. H.; Shim, H. W.

    1997-01-01

    This study has performed aiming to provide the government with the basic input to establish `the comprehensive promotion plan for utilization, research and development of nuclear energy` and `the mid- and long-term nuclear research and development program`, thus the government set it up as a national plan after endorsement of Atomic Energy Commission. Next, the feasibility study of the proton accelerators construction which is expected to use for nuclear research and development and industry. And a systematic and integrated research and development management system for the large-scale projects has been studied considering the inherent uncertainty and high risk of research and development. (author). 24 tabs., 6 figs.

  18. Ultrastructural investigation of root canal dentine surface after application of active ultrasonic method

    Directory of Open Access Journals (Sweden)

    Mitić Aleksandar

    2008-01-01

    Full Text Available INTRODUCTION The basic work principle of all ultrasonic techniques is the piezoelectric effect of producing high frequency ultrasounds of small length, which are transmitted over the endodontic extensions or canal instruments into the root canal. When in contact with the tissue, ultrasonic vibrations are converted into mechanical oscillations. Ultrasonic waves and the obtained oscillations along with the synergic effect of irrigation bring about the elimination of smear layer from the root canal walls. OBJECTIVE The aim of the study was to ultrastucturally examine the effect of smear layer removal from the walls of canals by the application of the active ultrasonic method without irrigation, that is by the application of ultrasound and irrigation using distilled water and 2.5% NaOCl. METHOD The investigation comprised 35 single-canal, extracted human teeth. After removal of the root canal content, experimental samples were divided into three groups. According to the procedure required, the first group was treated by ultrasound without irrigation; the second one by ultrasound with irrigation using distilled water; and the third group was treated by ultrasound and irrigation using 2.5% NaOCl solution. The control samples were treated by machine rotating instruments (Pro-File and were rinsed by distilled water. RESULTS The obtained results showed that the ultrasonic treatment of the root canal without irrigation did not remove the smear layer. The dentine canals are masked, and big dentine particles are scattered on the intertubular dentine. The ultrasonic treatment by using irrigation with distilled water provides cleaner dentine walls and open dentine tubules but with smaller particles on the intertubular dentine. The ultrasound treatment by using irrigation with 2.5% NaOCl solution provides a clean intertubular dentine surface without a smear layer and clearly open dentine tubules. CONCLUSION Instrumentation of the root canal by application of

  19. Influence of flexion angle of files on the decentralization of oval canals during instrumentation

    Directory of Open Access Journals (Sweden)

    Maria Antonieta Veloso Carvalho de OLIVEIRA

    2015-01-01

    Full Text Available The aim of this study was to evaluate the influence of the flexion angle of files on the decentralization of root canals during instrumentation. Fifteen lower incisors were instrumented with Protaper Universal files and radiographed in two directions (mesiodistal and buccolingual before and after instrumentation with a #15 K-file in position for evaluating the flexion angle of files. The specimens were also scanned before and after instrumentation using micro-computed tomography to obtain the canal area and the distance from the center position of the file to the canal walls. Sections located 1.0 mm (end of the canal, 3.0 mm (apical third, 9.0 mm (middle third, and 15.0 mm (cervical third from the apex were verified. After instrumentation, the flexion angles of files decreased by an average of 0.76º in the buccolingual direction and 1.92º in the mesiodistal direction (p < 0.001; the canal area increased by an average of 0.58, 0.37, 0.23 and 0.13 mm2 from the cervical to the end of the root canal (p < 0.001. Non-instrumented areas were observed on the buccal and lingual walls, and effective action of files was determined on the mesial and distal walls. The sections from the end of the canal showed canal deviation toward the lingual wall, whereas the other sections showed deviation toward the buccal wall. The flexion angles of files influence the final shape of the root canal, resulting in file decentralization along the pathway of the canal.

  20. Canal isthmus in mandibular first premolars studied by micro-computed tomography%下颌第一前磨牙根管峡部的显微CT研究

    Institute of Scientific and Technical Information of China (English)

    胡晓菁; 杨健

    2011-01-01

    Objective; To investigate the incidence and location of the isthmus in mandibular first premolars with 2 or more canals. Methods: 40 human mandibular first premolars with 2 or mure canals were included in the study. Each tooth was scanned by micro-CT with resolution of 15 μm and section thickness of 30 μm. The cross- sectional views of the apical 0-6 mm of the roots were obtained. The number of sections showing isthmus at each level was recorded and compared. Results: In human mandibular first premolars with 2 or more canals at each 1 mm level from apical 0-6 mm, the incidence(% ) of isthmus was 6. 0,18.5 ,78. 6,80,79. 2 and 72. 5 respectively. Conclusion; Mandibular first premolars have a high incidence of isthmus. In the apical 3 ~4 mm area,the isthmus incidence is the highest.%目的:运用显微CT研究非单根管的下颌第一前磨牙根尖0~6 mm区域根管峡部出现的位置和发生率,为提高根管治疗和根尖外科手术的成功率提供解剖学依据.方法:从147颗下颌第一前磨牙中挑选出非单根管的40颗,用显微CT以15 μm分辨率、30 μm层厚扫描及软件三维重建,观察并记录根尖0~6 mm区域各横截面的峡部形态及分布情况,并对根管系统的解剖形态三维重建后,进行二维、三维图像分析.结果:非单根管的下颌第一前磨牙距根尖0~6 mm区域内根管峡部的发生率(%)由根方向冠方以每l mm为间距依次为:6%、18.5%、78.6%、80%、79.2%、72.5%.结论:非单根管下颌第一前磨牙根管峡部在距根尖3~6 mm区域高发,其中距根尖3~4 mm区域发生率最高.

  1. Nuclear fuel cycle assessment of India: A technical study for U.S.-India cooperation

    Science.gov (United States)

    Krishna, Taraknath Woddi Venkat

    The recent civil nuclear cooperation proposed by the Bush Administration and the Government of India has heightened the necessity of assessing India's nuclear fuel cycle inclusive of nuclear materials and facilities. This agreement proposes to change the long-standing U.S. policy of preventing the spread of nuclear weapons by denying nuclear technology transfer to non-NPT signatory states. The nuclear tests in 1998 have convinced the world community that India would never relinquish its nuclear arsenal. This has driven the desire to engage India through civilian nuclear cooperation. The cornerstone of any civilian nuclear technological support necessitates the separation of military and civilian facilities. A complete nuclear fuel cycle assessment of India emphasizes the entwinment of the military and civilian facilities and would aid in moving forward with the separation plan. To estimate the existing uranium reserves in India, a complete historical assessment of ore production, conversion, and processing capabilities was performed using open source information and compared to independent reports. Nuclear energy and plutonium production (reactor- and weapons-grade) was simulated using declared capacity factors and modern simulation tools. The three-stage nuclear power program entities and all the components of civilian and military significance were assembled into a flowsheet to allow for a macroscopic vision of the Indian fuel cycle. A detailed view of the nuclear fuel cycle opens avenues for technological collaboration. The fuel cycle that grows from this study exploits domestic thorium reserves with advanced international technology and optimized for the existing system. To utilize any appreciable fraction of the world's supply of thorium, nuclear breeding is necessary. The two known possibilities for production of more fissionable material in the reactor than is consumed as fuel are fast breeders or thermal breeders. This dissertation analyzes a thermal

  2. In vitro study of the sealing ability of root canal sealers%根管充填糊剂根尖封闭性的体外研究

    Institute of Scientific and Technical Information of China (English)

    肖喜梅; 张春阳; 苏凡; 段艳艳; 苏勤; 林浩志

    2014-01-01

    Objective To evaluate the sealing ability of three root canal sealers(AH-Plus、iRoot SP and GuttaFlow). Methods Sixty-eight extracted single-rooted human mandibular premolars were randomly divided into 6 groups including four test groups (named A、B、C、D) (n=12) and a positive control group (named E) (n=10) and a negative control (named F) (n=10). All teeth were prepared by crown-down techniques with K3 Nickel-Tita-nium files. After that, all root canals were obturated as follows:group A and group B were filled with Resin-based sealers AH-Plus and biocompatible ceramic sealers iRoot SP respectively using a lateral condensation technique;group C and group D were filled with biocompatible ceramic sealers iRoot SP and Silicone-based sealers Gutta-flow respectively using a single cone technique;group E and group F (the control groups ) were filled with gutta-percha without any sealer using a lateral condensation technique. All samples were immersed in indian ink to be stained. Among these samples, the root surface in experimental and positive control groups were coated with nail polish except for the apical 2mm, and the whole root surface in negative control group was coated with two layers of nail polish. The micro-leakage of the 6 groups was evaluated by dye penetration with the transparent method. The length of dye penetration was measured with image J under the stereograph microscope. The data was ana-lyzed using ANOVA;the remaining teeth were sectioned and examined under scanning electron microscope (SEM) to observe the micro-structure. Results The mean length of dying line of four test groups were 1.02± 0.46mm,1.05±0.42mm,1.02±0.45mm and 1.16±0.43mm, respectively. There is no significant difference among each group in the length of dying line (P>0.05). SEM revealed there was gap between the dentinal walls and the filling paste in each group. Conclusion Three root canal sealers do not completely fill the root canal system and the sealing ability of AH

  3. Application study of nuclear technologies for dual use

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Jae Gon; Chung, W. S.; Park, W. S.; Lee, K. W.; Cha, H. K.; Han, M. H.; Yoon, J. S.; Honh, D. H.; Park, J. Y.; Lee, C. H.; Yeo, J. W.; Jung, M.; Ra, G. H

    2000-02-01

    The projects for the joint development of technology common to the civilian and military sectors are being carried out at national level to maximize the utilization of limited resources. The technologies have been identified through a process which considered whether they are duplicates of the present military technology, whether they are necessary, and whether their realization is feasible. In addition, the problems surfaced during the identification process have been analyzed and suggestions to vitalize the military application of civilian nuclear technology are presented in the contexts of personal channel, institutional networking, R and D information exchange, and budgetary support. (author)

  4. STUDY ON NUCLEAR MATRIX PROTEINS FROM HUMAN BREAST CARCINOMA

    Institute of Scientific and Technical Information of China (English)

    HE Qian; ZHANG Shu-qun; CHU Yong-lie; JIA Xiao-li; JIANG Jian-tao

    2009-01-01

    Objective To investigate the marker protein of human breast carcinoma from nuclear matrix proteins (NMPs).Methods NMPs were injected subcutaneously into rabbit to get antiserum, which was used to detect the NMPs specificity for breast carcinoma.Results There was an apparent positive band (100kD) in the NMPs of breast carcinoma, which did not exist in normal breast and other tumors that were detected.Conclusion One or one group of 100kD NMPs were found to be related to human breast carcinoma, which may be involved in the carcinogenesis and development of human breast carcinoma and valuable for breast carcinoma diagnosis.

  5. Initial studies to assess microbial impacts on nuclear waste disposal

    Energy Technology Data Exchange (ETDEWEB)

    Horn, J.M.; Meike, A.; McCright, R.D. [Lawrence Livermore National Lab., CA (United States); Economides, B. [Univ. of California, Berkeley, CA (United States). Dept. of Geology and Geophysics

    1996-02-20

    The impacts of the native and introduced bacteria on the performance of geologic nuclear waste disposal facilities should be evaluated because these bacteria could promote corrosion of repository components and alteration of chemical and hydrological properties of the surrounding engineered and rock barriers. As a first step towards investigating these potentialities, native and introduced bacteria obtained from post-construction Yucca Mountain (YM) rock were isolated under varying conditions, including elevated temperature, low nutrient availability, and the absence of available oxygen. Individual isolates are being screened for activities associated with microbially induced corrosion of metals (MIC). Preliminary determination of growth rates of whole YM microbial communities under varying conditions was also undertaken.

  6. [Upper lateral incisor with 2 canals].

    Science.gov (United States)

    Fabra Campos, H

    1991-01-01

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

  7. Bilateral duplication of the internal auditory canal

    Energy Technology Data Exchange (ETDEWEB)

    Weon, Young Cheol; Kim, Jae Hyoung; Choi, Sung Kyu [Seoul National University College of Medicine, Department of Radiology, Seoul National University Bundang Hospital, Seongnam-si (Korea); Koo, Ja-Won [Seoul National University College of Medicine, Department of Otolaryngology, Seoul National University Bundang Hospital, Seongnam-si (Korea)

    2007-10-15

    Duplication of the internal auditory canal is an extremely rare temporal bone anomaly that is believed to result from aplasia or hypoplasia of the vestibulocochlear nerve. We report bilateral duplication of the internal auditory canal in a 28-month-old boy with developmental delay and sensorineural hearing loss. (orig.)

  8. 33 CFR 117.285 - Grand Canal.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Grand Canal. 117.285 Section 117.285 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.285 Grand Canal. (a) The draw of the Lansing Island bridge, mile 0.7, shall open on...

  9. 33 CFR 117.453 - Houma Canal.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Houma Canal. 117.453 Section 117.453 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.453 Houma Canal. The draw of the S3197 bridge, mile 1.7 at Houma, shall open on signal...

  10. 33 CFR 117.438 - Company Canal.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Company Canal. 117.438 Section 117.438 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.438 Company Canal. (a) The draw of the S1 bridge, mile 0.4 at Lockport, shall open...

  11. Neuronal hyperplasia in the anal canal

    DEFF Research Database (Denmark)

    Fenger, C; Schrøder, H D

    1990-01-01

    In a consecutive series of minor surgical specimens from the anal canal, neuronal hyperplasia was found in nine of 56 haemorrhoidectomy specimens and in four of 23 fibrous polyps. In an additional series of 14 resections of the anal canal, neuronal hyperplasia was present in six cases, of which...

  12. 33 CFR 117.787 - Gowanus Canal.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Gowanus Canal. 117.787 Section 117.787 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New York § 117.787 Gowanus Canal. The draws of the Ninth Street Bridge, mile 1.4, the Third...

  13. Blending Canal Surfaces Based on PH Curves

    Institute of Scientific and Technical Information of China (English)

    Chen-Dong Xu; Fa-Lai Chen

    2005-01-01

    In this paper, a new method for blending two canal surfaces is proposed. The blending surface is itself a generalized canal surface, the spine curve of which is a PH (Pythagorean-Hodograph) curve. The blending surface possesses an attractive property - its representation is rational. The method is extensible to blend general surfaces as long as the blending boundaries are well-defined.

  14. 33 CFR 117.445 - Franklin Canal.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Franklin Canal. 117.445 Section 117.445 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Louisiana § 117.445 Franklin Canal. The draw of the Chatsworth Bridge, mile 4.8 at Franklin, shall...

  15. 33 CFR 117.1045 - Hood Canal.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Hood Canal. 117.1045 Section 117.1045 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Washington § 117.1045 Hood Canal. The draw of the Washington State pontoon highway bridge near...

  16. DESIGN OF SEDIMENT TRANSPORTING CANAL SECTIONS

    Institute of Scientific and Technical Information of China (English)

    Prabhata K.SWAMEE; Nimisha SWAMEE

    2004-01-01

    Design equations for minimum area or maximum velocity canal-sections for transport of bulk sediment carried by water have been obtained. Such canals are economically feasible in the terrain where large slopes are available. The design procedure is illustrated by a practical example.

  17. The nuclear data, A key component for reactor studies, Overview of AREVA NP needs and applications

    Directory of Open Access Journals (Sweden)

    Ravaux Simon

    2016-01-01

    Full Text Available The quality of the nuclear data is essential for AREVA NP. Indeed, many AREVA NP activities such as reactor design, safety studies or reactor instrumentation use them as input data. So, the nuclear data can be considered as a key element for AREVA NP. REVA NP’s contribution in the improvement of the nuclear data consists in a joint effort with the CEA. It means a financing and a sharing of information which can give an orientation to the future research axis. The aim of this article is to present the industrial point of view from AREVA NP on the research on nuclear data. Several examples of collaborations with the CEA which have resulted in an improvement of the nuclear data are presented.

  18. On safety management and nuclear safety - A frame of reference for studies of safety management with examples from non-nuclear contects of relevance for nuclear safety

    Energy Technology Data Exchange (ETDEWEB)

    Svenson, O.; Allwin, P. [Stockholm Univ. (Sweden); Salo, I. [Lund Univ. (Sweden)

    2004-03-01

    The report includes three case studies of safety management. The studies are presented as chapters, but are written in a format that makes them easy to read separately. Two of the studies cover regulators (the Swedish Civil Aviation Safety Authority, Luftfartsinspektionen) and the Norwegian Petroleum Directorate) and one a regulated activity/industry (a car manufacturer, Volvo Car). The introduction outlines a living system framework and relates this to concepts used in organizational management. The report concludes with some findings with potential relevance for safety management in the nuclear power domain. In the next phase of the work, the regulated counterparts of the regulators here will be investigated in addition to a fourth case study of a regulated activity/industry. (au)

  19. MANAGEMENT OF LUMBAR SPINAL CANAL STENOSIS

    Directory of Open Access Journals (Sweden)

    Mukhergee G. S

    2016-06-01

    Full Text Available BACKGROUND Spinal stenosis is one of the most common conditions in the elderly. It is defined as a narrowing of the spinal canal. The term stenosis is derived from the Greek word for narrow, which is “Stenos”. The first description of this condition is attributed to Antoine portal in 1803. Verbiest is credited with coining the term spinal stenosis and the associated narrowing of the spinal canal as its potential cause. [1-10] Kirkaldy–Willis subsequently described the degenerative cascade in the lumbar spine as the cause for the altered anatomy and pathophysiology in spinal stenosis. [11-15] If compression does not occur, the canal should be described as narrow but not stenotic. Some studies defined lumbar spinal stenosis as a “narrowing of the osteoligamentous vertebral canal and/or the intervertebral foramina causing compression of the thecal sac and/or the caudal nerve roots; at a single vertebral level, narrowing may affect the whole canal or part of it” (Postacchini 1983. This definition distinguished between disc herniation and stenosis. [16] . The most common type of spinal stenosis is caused by degenerative arthritis of the spine. Hypertrophy and ossification of the posterior longitudinal ligament which usually are confined to the cervical spine, and diffuse idiopathic skeletal hyperostosis (DISH syndrome also may result in an acquired form of spinal stenosis. Congenital forms caused by disorders such as achondroplasia and dysplastic spondylolisthesis are much less common. Congenital spinal stenosis usually is central and is evident or imaging studies. Idiopathic congenital narrowing usually involves the anteroposterior dimension of the canal secondary to short pedicles; the patient otherwise is normal. In contrast, in achondroplasia, the canal is narrowed in the anteroposterior plane owing to shortened pedicles and in lateral dimension because of diminished interpedicular distance. Acquired forms of spinal stenosis usually are

  20. A brief comparative study of the wind and nuclear energy; Um breve estudo comparativo entre as energias eolica e nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Flores, Tarcisio Santos [Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Diamantina, MG (Brazil). Inst. de Ciencia e Tecnologia

    2015-07-01

    It is apparent the human need to use electricity in the current globalized world. And along with the social and industrial and beyond the everyday comfort evolution came the abuse of power. Aware that Brazil is used as an energy source originating from hydroelectric and that it does not include all domestic demand, should be studied energy sources that can assist it. Two clean and cheap energy alternatives which can contribute to reducing the environmental impacts such as global warming and water shortages are wind and nuclear energy. Which again, exhibit ideal characteristics to serve as alternative sources for electricity production, mainly in the dry season. (author)

  1. Tissue engineering in endodontics: root canal revascularization.

    Science.gov (United States)

    Palit Madhu Chanda; Hegde, K Sundeep; Bhat, Sham S; Sargod, Sharan S; Mantha, Somasundar; Chattopadhyay, Sayan

    2014-01-01

    Root canal revascularization attempts to make necrotic tooth alive by the use of certain simple clinical protocols. Earlier apexification was the treatment of choice for treating and preserving immature permanent teeth that have lost pulp vitality. This procedure promoted the formation of apical barrier to seal the root canal of immature teeth and nonvital filling materials contained within root canal space. However with the success of root canal revascularization to regenerate the pulp dentin complex of necrotic immature tooth has made us to rethink if apexification is at the beginning of its end. The objective of this review is to discuss the new concepts of tissue engineering in endodontics and the clinical steps of root canal revascularization.

  2. Clinical management of infected root canal dentin.

    Science.gov (United States)

    Love, R M

    1996-08-01

    Several hundred different species of bacteria are present in the human intraoral environment. Bacterial penetration of root canal dentin occurs when bacteria invade the root canal system. These bacteria may constitute a reservoir from which root canal reinfection may occur during or after endodontic treatment. The learning objective of this article is to review endodontic microbiology, update readers on the role of bacteria in pulp and periapical disease, and discuss the principles of management of infected root canal dentin. Complete debridement, removal of microorganisms and affected dentin, and chemomechanical cleansing of the root canal are suggested as being the cornerstones of successful endodontic therapy, followed by intracanal medication to remove residual bacteria, when required.

  3. Type III apical transportation of root canal

    Directory of Open Access Journals (Sweden)

    Shiv P Mantri

    2012-01-01

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

  4. Up-regulation of gelatinases and tissue type plasminogen activator by root canal sealers in human osteoblastic cells.

    Science.gov (United States)

    Huang, Fu-Mei; Yang, Shun-Fa; Chang, Yu-Chao

    2008-03-01

    Histologic investigations have demonstrated that root canal sealers can induce mild to severe inflammatory alternations. However, there is little information on the precise mechanisms about root canal sealer-induced inflammatory reaction. The proteolysis of extracellular matrix by matrix metalloproteinases (MMPs) and plasminogen activators (PAs) seems to be a key initiating event for the progression of the inflammatory process. The aim of this study was to investigate the effects of epoxy resin-based root canal sealer AH26 and zinc oxide-eugenol-based root canal sealer Canals and one paste sealer N2 on the expression of MMPs and PAs in human osteoblastic cell line U2OS cells. The levels of gelatinolytic and caseinolytic activities were measured by gelatin and casein zymography. The results showed that AH26, Canals, and N2 were cytotoxic to U2OS cells in a concentration-dependent manner (P inflammation.

  5. Radiography of the mandible prior to endosseous implant treatment. Localization of the mandibular canal and assessment of trabecular bone

    Energy Technology Data Exchange (ETDEWEB)

    Lindh, C.

    1996-03-01

    Mandibular autopsy specimens were examined with different radiographic techniques in order to evaluate the visibility of the mandibular canal and the measurement accuracy of distances related to the mandibular canal. Hypocycloidal, spiral and computed tomography (CT) were superior to periapical and panoramic radiography in visualizing the mandibular canal. The tomographic techniques were more accurate when measurements of distances related to the mandibular canal were performed. No difference in measurement accuracy was found between the tomographic techniques. Concerning visibility of the mandibular canal, interobserver agreement was lowest for periapical radiography and highest for CT. Intraobserver agreement was moderate or good for all techniques. A high interobserver variation was found for measurability of distances related to the mandibular canal. The trabecular bone tissue in mandibular autopsy specimens was studied concerning different characteristics. A classification system to be used prior to implant treatment, based on the trabecular pattern in periapical radiographs, was proposed. 74 refs.

  6. MRI Findings in Spinal Canal Stenosis

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    Maryam Barzin

    2010-05-01

    Full Text Available Spinal canal stenosis results from progressive narrowing of the central spinal canal and the lateral recesses. Primary (congenital lumbar spinal stenosis is associated with achondroplastic dwarfism. The spinal canal may become narrowed by bulging or protrusion of the intervertebral disc annulus, herniation of the nucleus pulposus posteriorly, thickening of the posterior longitudinal ligament, hypertrophy of the facet joints, hypertrophy of the ligamentum flavum, epidural fat deposition, spondylosis of the intervertebral disc margins and uncovertebral joint hypertrophy in the neck. The central canal and the neurorecess may be compromised by tumor infiltration, such as metastatic disease, or by infectious spondylitis."nAP diameter of the normal adult cervical canal has a mean value of 17-18 mm at vertebral levels C3-5. The lower cervical canal measures 12-14 mm. Cervical stenosis is associated with an AP diameter of less than 10 mm. The thoracic spinal canal varies from 12 to 14 mm in diameter in the adult. The diameter of the normal lumbar spinal canal varies from 15 to 27 mm. Lumbar stenosis results from a spinal canal diameter of less than 12 mm in some patients; a diameter of 10 mm is definitely stenotic."nSpinal MRI is the most suitable technique for the diagnosis of spinal stenosis. The examination should be performed using thin sections (3 mm and high resolution, including the axial and sagittal planes using T1-weighted, proton-density, and T2-weighted techniques. The bony and osteophytic components are seen best using a T2-weighted gradient-echo technique."nOn MRI, findings of spinal stenosis have a variable presentation depending on the specific disease. The goal of spinal imaging is to localize the site and level of disease and to help differentiate between conditions in which patients require surgery or conservative treatment."nIn this presentation, different kinds of spinal canal stenosis and their MRI findings would be discussed.

  7. The spiral ganglion and Rosenthal's canal in beluga whales.

    Science.gov (United States)

    Sensor, Jennifer D; Suydam, Robert; George, John C; Liberman, M C; Lovano, Denise; Rhaganti, Mary Ann; Usip, Sharon; Vinyard, Christopher J; Thewissen, J G M

    2015-12-01

    With the increase of human activity and corresponding increase in anthropogenic sounds in marine waters of the Arctic, it is necessary to understand its effect on the hearing of marine wildlife. We have conducted a baseline study on the spiral ganglion and Rosenthal's canal of the cochlea in beluga whales (Delphinapterus leucas) as an initial assessment of auditory anatomy and health. We present morphometric data on the length of the cochlea, number of whorls, neuron densities along its length, Rosenthal's canal length, and cross-sectional area, and show some histological results. In belugas, Rosenthal's canal is not a cylinder of equal cross-sectional area, but its cross-section is greatest near the apex of the basal whorl. We found systematic variation in the numbers of neurons along the length of the spiral ganglion, indicating that neurons are not dispersed evenly in Rosenthal's canal. These results provide data on functionally important structural parameters of the beluga ear. We observed no signs of acoustic trauma in our sample of beluga whales.

  8. Root canal length measurement in teeth with electrolyte compensation.

    Science.gov (United States)

    Nam, K C; Kim, S C; Lee, S J; Kim, Y J; Kim, N G; Kim, D W

    2002-03-01

    Electronic root canal length measurement devices have made it easier and faster to measure the root canal length of a tooth compared with the conventional radiographic method. Of these electronic apex locators, the frequency-dependent type features greater accuracy and convenience in operation. However, its accuracy is still influenced by the presence of blood and/or the various electrolytes used in root canal therapy. This study describes the development of a new frequency-dependent electronic apex locator featuring electrolyte compensation, utilising an impedance ratio and voltage difference technique to minimise the influence of electrolytes on the accuracy of root canal length measurement. The errors for distances from file tips to apical constrictions were determined in vivo with the device operating with electrolyte compensation. The measured lengths were compared with the true lengths of the extracted teeth determined using a microscope. The mean error was +0.14+/-0.27mm, and 95.2% of the measurements were within the clinical tolerance of +/-0.5mm. It was also found that the degree of accuracy was not dependent on the size of the apical foramen (p = 0.74).

  9. Effect of Canal Bank Filtration on Quality of Water Long Hyderabad City

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    IMDAD ALI KANDHAR

    2016-07-01

    Full Text Available The focus of the present study was to examine the effect of canal bank filtration on the quality of water and the geological settings along the banks of canals at the shallow depth aquifers. The four Model wells were drilled at different locations of the Line channel, Pinyari and phulali canals in the study area. The samples of soil were collected throughout drilling of the model wells for the analysis of grain size distribution .In addition to this, canal water and model well water samples were collected and analyzed for the water quality characteristics during winter and summer seasons. The analysis of soil and water samples reveals that the ground water is influenced by the grain size distribution, hydraulic conductivity and the location of the model Wells. The model well that has higher percentage of 0.075 mm of grain size distribution(hydraulic conductivity between 10-25 ft/day was more suitable for the filtration of the canal water through its banks, followed by 0.15 mm of grain size distribution (hydraulic conductivity > 25ft/ day. Moreover, the present study also shows that the canal water filtration is suitable in terms of total alkalinity, nitrate-nitrogen, total iron and pH to get the potable water at the location near upstream of the canal, especially in the summer season.

  10. Comparative study on storage and disposal of liquid waste in nuclear medicine diagnostic; Estudio comparativo sobre almacenamiento y eliminacion de residuos liquidos para diagnostico en medicina nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez Vazquez, R.; Sanchez Garcia, M.; Santamarina Vazquez, F.; Soto Bua, M.; Montoya Pastor, A.; Luna Vega, V.; Mosquera Suueiro, J.; Otero Martinez, C.; Lobato Busto, R.; Pombar Camean, M.

    2011-07-01

    The aim of this paper presents a comparative study on the total activity of material discharge to public sewers and the activity concentration in the final point of discharge, for a typical installation of Nuclear Medicine, in the case of having no deposit or storage of liquid radioactive waste from diagnostic techniques, based on actual data from the Nuclear Medicine Department of our hospital.

  11. A simple method for routine monitoring of glyphosate and its main metabolite in surface waters using lyophilization and LC-FLD+MS/MS. Case study: canals with influence on Biscayne National Park.

    Science.gov (United States)

    Ramirez, Cesar E; Bellmund, Sarah; Gardinali, Piero R

    2014-10-15

    A novel method was developed for the analysis of the herbicide glyphosate and its main metabolite aminomethylphosphonic acid (AMPA) based on lyophilization. Sample preparation steps are limited to fortification with aspartic acid as internal standard and water removal by lyophilization (3-4 days for 72 samples), followed by suspension of dry residues in borate buffer (pH=9.0) and addition of ethylenediaminetetraacetic acid (EDTA) and 9-fluorenylmethylchloroformate (FMOC-Cl) for pre-column derivatization. The obtained derivatization mixture was injected on a highly endcapped C18 column where a basic pH gradient separation of the anionic analytes from neutral derivatization byproducts was achieved, with simultaneous quantitation by fluorescence and compound confirmation by tandem mass spectrometry. Method detection limits (for 20 mL samples) were 0.058 μg/L and 0.108 μg/L for glyphosate and AMPA, respectively. The method had a high dynamic range (0.1-50.0 μg/L) which allowed quantitation at both background and high levels of the herbicide. As a case study, the methodology was successfully applied to detect the occurrence of these compounds in water canals managed by the South Florida Water Management District. These canals will be used as freshwater source to hydrate estuarine wetlands of Biscayne National Park under the Comprehensive Everglades Restoration Project, in order to decrease ecosystem stress from hypersaline conditions caused by anthropogenic reduction of historical freshwater flow towards the Biscayne Bay. Method development, validation, advantages, limitations and measured environmental concentrations are discussed. This methodology has minimal requirements in terms of materials, instruments and analyst training, which could represent a desirable tool for laboratories interested in the monitoring of glyphosate in surface waters.

  12. Candida auris sp. nov., a novel ascomycetous yeast isolated from the external ear canal of an inpatient in a Japanese hospital.

    Science.gov (United States)

    Satoh, Kazuo; Makimura, Koichi; Hasumi, Yayoi; Nishiyama, Yayoi; Uchida, Katsuhisa; Yamaguchi, Hideyo

    2009-01-01

    A single strain of a novel ascomycetous yeast species belonging to the genus Candida was isolated from the external ear canal of an inpatient in a Japanese hospital. Analyses of the 26S rDNA D1/D2 domain, nuclear ribosomal DNA ITS region sequences, and chemotaxonomic studies indicated that this strain represents a new species with a close phylogenetic relationship to Candida ruelliae and Candida haemulonii in the Metschnikowiaceae clade. This strain grew well at 40 degrees C, but showed slow and weak growth at 42 degrees C. The taxonomic description of Candida auris sp. nov. is proposed (type strain JCM15448T= CBS10913T= DSM21092T).

  13. A Study on Nuclear Blast Overpressure on Buildings and other infrastructures using Geospatial Technology

    Directory of Open Access Journals (Sweden)

    D. Thirumalaivasan

    2012-01-01

    Full Text Available An Improvised Nuclear Device or nuclear bomb of yield 10 kiloton to 20 kiloton explodes in any major city due to terrorism or any other reason can cause catastrophic damages on the building's and other infrastructures and also shutting down of critical life-safety systems.. The explosion may produce blast overpressure, thermal radiation and harmful instant and delayed nuclear radiations. The buildings and other Civil Engineering structures may be highly vulnerabke due to the blast overpressure from the explosion and thermal radiation. In this present study Remote Sensing and Geographical Information System is effectively utilized to model the blast affected zone from the ground Zero of the study area. This study also introduces different emperical methods to estimate blast loads and structural response. The purpose is to describe the blast effects of a nuclear explosion, thereby informing people of the real dangers posed by nuclear weapons. Therefore, as a case study, we consider a hypothetical City as a target for detonation. Due to security reasons the data for existing City is not used for this study purpose. The study area is hypothetically detonated with a 15 kiloton yield nuclear explosion as surface blast and wind spped is assumed as 5 meters per second.

  14. Seaborg's Plutonium? A Case Study in Nuclear Forensics

    Science.gov (United States)

    Norman, Eric B.; Thomas, Keenan J.; Telhami, Kristina E.

    2015-10-01

    Passive X-ray and gamma-ray analysis was performed on UC Berkeley's EH&S Sample S338. The object was found to contain 239Pu. No other radioactive isotopes were observed. The mass of 239Pu contained in this object was determined to be 2.0 +- 0.3 μg. These observatio