WorldWideScience

Sample records for analysis surrounding implant-supported

  1. Evaluation of Tissues Surrounding Implant Supported Fixed Partial Denture with and without Cantilever Extension

    OpenAIRE

    Fazel, A.; M. Rismanchian

    2007-01-01

    Objective: The aim of this study was to evaluate and compare the status of supporting tissue around implant-supported fixed partial denture with or without cantilever clinically and radiographically during a four-year period.Materials and Methods: One hundred and fifty nine patients who were treated by 482 implants supported fixed partial prosthesis with and without cantilever after at least four years of treatment, were evaluated. Clinical and radiographic indices of plaque index,probing poc...

  2. Evaluation of Tissues Surrounding Implant Supported Fixed Partial Denture with and without Cantilever Extension

    Directory of Open Access Journals (Sweden)

    A. Fazel

    2007-12-01

    Full Text Available Objective: The aim of this study was to evaluate and compare the status of supporting tissue around implant-supported fixed partial denture with or without cantilever clinically and radiographically during a four-year period.Materials and Methods: One hundred and fifty nine patients who were treated by 482 implants supported fixed partial prosthesis with and without cantilever after at least four years of treatment, were evaluated. Clinical and radiographic indices of plaque index,probing pocket depth, bleeding index, and marginal bone loss were measured. Collected data were analyzed by Mann-Whitney, Fridman and repeated-measures ANOVA tests using SPSS software.Results: The overall survival rate of implant supported prosthesis was 95.9% after at least four years of treatment. The success rates of implant supported fixed prosthesis with and without cantilever were 94.6% and 96.8% respectively. Marginal bone loss in the cantilevered fixed prosthesis was significantly more than the second group after two and four years of treatment (P<0.001, however, all the clinical indices were not significantly different.Conclusion: Considering the guidelines of cantilever prosthesis applications, using the cantilevered fixed partial dentures have a similar and comparable prognosis as the traditional implant-supported fixed prostheses.

  3. Effect of axial loads on implant-supported partial fixed prostheses by strain gauge analysis

    Directory of Open Access Journals (Sweden)

    Luis Gustavo Oliveira de Vasconcellos

    2011-12-01

    Full Text Available OBJECTIVES: The present study used strain gauge analysis to perform an in vitro evaluation of the effect of axial loading on 3 elements of implant-supported partial fixed prostheses, varying the type of prosthetic cylinder and the loading points. MATERIAL AND METHODS: Three internal hexagon implants were linearly embedded in a polyurethane block. Microunit abutments were connected to the implants applying a torque of 20 Ncm, and prefabricated Co-Cr cylinders and plastic prosthetic cylinders were screwed onto the abutments, which received standard patterns cast in Co-Cr alloy (n=5. Four strain gauges (SG were bonded onto the surface of the block tangentially to the implants, SG 01 mesially to implant 1, SG 02 and SG 03 mesially and distally to implant 2, respectively, and SG 04 distally to implant 3. Each metallic structure was screwed onto the abutments with a 10 Ncm torque and an axial load of 30 kg was applied at five predetermined points (A, B, C, D, E. The data obtained from the strain gauge analyses were analyzed statistically by RM ANOVA and Tukey's test, with a level of significance of p<0.05. RESULTS: There was a significant difference for the loading point (p=0.0001, with point B generating the smallest microdeformation (239.49 µε and point D the highest (442.77 µε. No significant difference was found for the cylinder type (p=0.748. CONCLUSIONS: It was concluded that the type of cylinder did not affect in the magnitude of microdeformation, but the axial loading location influenced this magnitude.

  4. An analysis of the implant-supported overdenture in the edentulous mandible.

    Science.gov (United States)

    Chen, K-W; Lin, T-M; Liu, P-R; Ramp, L C; Lin, H-J; Wu, C-T; Pan, Y-H

    2013-01-01

    This investigation examined the cumulative survival rate of the implant-supported overdenture using two types of attachments in patients treated at Show Chwan Memorial Hospital Implant Center from 1992 to 2006. Fifty-one patients (30 men and 21 women) were treated with mandibular implant-supported overdentures. Attachment systems used were the Hader bar with bilateral, cast ERA attachments (Group A, 31 patients with 15 men and 16 women, 134 implants) and the Hader bar with bilateral, distal extension cantilevers (Group B, 20 patients with 15 men and 5 women, 85 implants). Two hundred and four implants remained at the end of the follow-up period. Among failed implants, 10 implants were in Group A (failure rate: 10/134 = 7·5%), whereas five implants were in Group B (failure rate: 5/85 = 5·9%). Sixty-six point seven per cent (10/15) of failed implants were placed in the distal anterior mandible, and 33·3% (5/15) were placed in the middle anterior mandible. Survival was also examined with respect to condition of the opposing arch. Patients wearing a maxillary removable partial denture had the highest implant failure rate (5/51 = 9·8%), whereas the failure rate of the maxillary complete denture group was only 5·7%. The most frequent need for maintenance was wear over patrix component of ERA or Hader clip (n = 56). Eight patients experienced connector fracture between ERA and Hader bar, and one experienced distal extension cantilever fracture. The implant-supported overdenture can be an effective and reliable alternative to the conventional complete mandibular denture. Fewer prosthetic complications were seen in overdentures retained with distal extension cantilever attachments. PMID:23121231

  5. Three-Dimensional Finite Element Analysis of Anterior Single Implant-Supported Prostheses with Different Bone Anchorages

    OpenAIRE

    Fellippo Ramos Verri; Joel Ferreira Santiago Júnior; Daniel Augusto de Faria Almeida; Ana Caroline Gonçales Verri; Victor Eduardo de Souza Batista; Cleidiel Aparecido Araujo Lemos; Pedro Yoshito Noritomi; Eduardo Piza Pellizzer

    2015-01-01

    The aim of this study was to evaluate the stress distribution of monocortical and bicortical implant placement of external hexagon connection in the anterior region of the maxilla by 3D finite element analysis (FEA). 3D models were simulated to represent a bone block of anterior region of the maxilla containing an implant (4.0 × 10.0 mm) and an implant-supported cemented metalloceramic crown of the central incisor. Different techniques were tested (monocortical, bicortical, and bicortical ass...

  6. Photoelastic Analysis on Different Retention Methods of Implant-Supported Prosthesis.

    Science.gov (United States)

    Pimentel, Angélica Castro; Manzi, Marcello Roberto; Polo, Cristiane Ibanhês; Sendyk, Claudio Luiz; da Graça Naclério-Homem, Maria; Sendyk, Wilson Roberto

    2015-06-01

    The aim of this study was to evaluate the stress distribution of different retention systems (screwed, cemented, and mixed) in 5-unit implant-supported fixed partial dentures through the photoelasticity method. Twenty standardized titanium suprastructures were manufactured, of which 5 were screw retained, 5 were cement retained, and 10 were mixed (with an alternating sequence of abutments), each supported by 5 external hexagon (4.0 mm × 11.5 mm) implants. A circular polariscope was used, and an axial compressive load of 100 N was applied on a universal testing machine. The results were photographed and qualitatively analyzed. We observed the formation of isochromatic fringes as a result of the stresses generated around the implant after installation of the different suprastructures and after the application of a compressive axial load of 100 N. We conclude that a lack of passive adaptation was observed in all suprastructures with the formation of low-magnitude stress in some implants. When cemented and mixed suprastructures were subjected to a compressive load, they displayed lower levels of stress distribution and lower intensity fringes compared to the screwed prosthesis. PMID:25198152

  7. An Investigation of Three types of Tooth Implant Supported Fixed Prosthesis Designs with 3D Finite Element Analysis

    Directory of Open Access Journals (Sweden)

    Sara Koosha

    2013-01-01

    Full Text Available Objective: Tooth/implant supported fixed prostheses may present biomechanical design problems, as the implant is rigidly anchored within the alveolus, whereas the tooth is attached by the periodontal ligament to the bone allowing movement. Many clinicians prefer tooth/implant supported fixed prosthesis designs with rigid connectors. However, there are some doubts about the effect of attachment placement in different prosthesis designs. The purpose of this study was to examine the stresses accumulated around the implant and natural teeth under occlusal forces using three dimensional finite element analysis (3D FEA.Materials and Methods: In this study, different connection designs of tooth/implant fixed prosthesis in distal extension situations were investigated by 3D FEA. Three models with various connection designs were studied; in the first model an implant rigidly connected to an abutment, in the second and third models an implant connected to abutment tooth with nonrigid connector in the distal part of the tooth and mesial part of the implant. In each model, a screw type implant (5×11mm and a mandibular second premolar were used. The stress values of these models loaded with vertical forces (250N were analyzed.Results: There was no difference in stress distribution around the bone support of the implant. Maximum stress values were observed at the crestal bone of the implant. In all models, tooth movement was higher than implant movement.Conclusion: There is no difference in using a rigid connector, non rigid connector in the distal surface of the tooth or in the mesial surface of an implant.

  8. A two-short-implant-supported molar restoration in atrophic posterior maxilla: A finite element analysis

    Science.gov (United States)

    2016-01-01

    PURPOSE The aim of this study was to investigate the stress distribution of 2-short implants (2SIs) installed in a severely atrophic maxillary molar site. MATERIALS AND METHODS Three different diameters of internal connection implants were modeled: narrow platform (NP), regular platform (RP), and wide platform (WP). The maxillary first molars were restored with one implant or two short implants. Three 2SI models (NP-oblique, NP-vertical, and NP-horizontal) and four single implant models (RP and WP in a centered or cantilevered position) were used. Axial and oblique loadings were applied on the occlusal surface of the crown. The von Mises stress values were measured at the bone-implant, peri-implant bone, and implant/abutment complex. RESULTS The highest stress distribution at the bone-implant interface and the peri-implant bone was noticed in the RP group, and the lowest stress distribution was observed in the 2SI groups. Cantilevered position showed unfavorable stress distribution with axial loading. 2SI types did not affect the stress distribution in oblique loading. The number and installation positions of the implant, rather than the bone level, influenced the stress distribution of 2SIs. The implant/abutment complex of WP presented the highest stress concentration while that of 2SIs showed the lowest stress concentration. CONCLUSION 2SIs may be useful for achieving stable stress distribution on the surrounding bone and implant-abutment complex in the atrophic posterior maxilla.

  9. Stress analysis on the free-end distal extension of an implant-supported mandibular complete denture

    Directory of Open Access Journals (Sweden)

    Gustavo Diniz Greco

    2009-06-01

    Full Text Available A comparative and qualitative analysis of the tensions generated in the cantilever region of an implant-supported mandibular complete denture was conducted using the three-dimensional finite element method. The mechanical properties of the components were input in the model and a load of 15 N was applied in pre-determined points. In the first simulation, the load was applied on the occlusal surface of the first premolar. In the second simulation, it was applied on the first and second premolars. In the third simulation, it was applied on the first and second premolars and on the first molar. The different occlusion patterns produced similar tension distributions in the cantilever region, which followed a similar pattern in the three simulations. In all of the cases, the highest levels of tension were located in the region of the first implant. However, as the loads were dislocated distally, the tensions increased considerably. The more extensive the cantilever, the more compromised will be the infrastructure, the prosthetic components and the implants. Regardless of the length of the cantilever, the highest tensions will always be located in the region of the implant next to the load application point.

  10. Analysis of load distribution in tooth-implant supported fixed partial dentures by the use of resilient abutment

    Directory of Open Access Journals (Sweden)

    Glišić Mirko

    2016-01-01

    Full Text Available Introduction. Differences between the tooth and implant response to load can lead to many biological and technical implications in the conditions of occlusal forces. Objective. The objective of this study was to analyze load distribution in tooth/implant-supported fixed partial dentures with the use of resilient TSA (Titan Shock Absorber, BoneCare GmbH, Augsburg, Germany abutment and conventional non-resilient abutment using finite element method. Methods. This study presents two basic 3D models. For one model a standard non-resilient abutment is used, and on the implant of the second model a resilient TSA abutment is applied. The virtual model contains drawn contours of tooth, mucous membranes, implant, cortical bones and spongiosa, abutment and suprastructure. The experiment used 500 N of vertical force, applied in three different cases of axial load. Calculations of von Mises equivalent stresses of the tooth root and periodontium, implants and peri-implant tissue were made. Results. For the model to which a non-resilient abutment is applied, maximum stress values in all three cases are observed in the cortical part of the bone (maximum stress value of 49.7 MPa. Measurements of stress and deformation in the bone tissue in the model with application of the resilient TSA abutment demonstrated similar distribution; however, these values are many times lower than in the model with non-resilient TSA abutment (maximum stress value of 28.9 MPa. Conclusion. Application of the resilient TSA abutment results in more equal distribution of stress and deformations in the bone tissue under vertical forces. These values are many times lower than in the model with the non-resilient abutment.

  11. An analysis of reliability and validity of the papilla index score of implant-supported single crowns of maxillary central incisors

    DEFF Research Database (Denmark)

    Peng, Min; Fei, Wei; Hosseini, Mandana;

    2012-01-01

    Objectives: To test the reliability and validity of the papilla index scores of the implant-supported single crowns (ISSCs) of maxillary central incisors. Materials and Methods: Twenty-five patients with 25 ISSCs were included. Two prosthodontists evaluated the papilla index score (PIS) of three ...

  12. Effect of the number of implants on stress distribution of anterior implant-supported fixed prostheses combined with a removable partial denture: a finite element analysis.

    Directory of Open Access Journals (Sweden)

    Minoo Mahshid

    2014-06-01

    Full Text Available The main goal of this study was to evaluate differences in stress distribution relevant to the number of implants under an anterior bridge when combined with a removable partial denture in the posterior region.Four three-dimensional finite element models (3D FEM were designed from a mandible containing an implant-supported bridge extending between canines, and a bilateral distal extension removable partial denture. A nonrigid connection was selected as the attachment method between the partial denture and the anterior implant-supported fixed prosthesis; 2, 3, 4 and 5 implants supporting the bridge all with 10mm length and 3.8 mm diameter were assessed. With the aid of the finite element program ANSYS 8.0, the models were loaded and von Mises stresses were evaluated.In spongy bone, stress forces showed a decrease from 2 implants to 4 implants but showed an increase in the 5-implant model. Stresses on cortical bone of terminal implants were in similar range in the 2-, 3- and 4-implant models. While, in the 5-implant model the amount of stresses on terminal implants increased dramatically. The stresses on implants were nearly similar in all models, with the greatest amount on terminal implants.Within the limitations of this study, 2-, 3- and 4-implant models showed less stress on cortical and spongy bone in comparison with the 5-implant model. The stresses transferred to implants were nearly similar.

  13. Masticatory function with implant-supported overdentures

    NARCIS (Netherlands)

    van Kampen, FMC; van der Bilt, A; Cune, MS; Fontijn-Tekamp, FA; Bosman, F

    2004-01-01

    The type of attachment that is used in implant-supported mandibular overdentures may influence the retention and stability of the prosthesis and, thus, masticatory function. In this within- subject cross- over clinical trial, we examined the hypothesis that greater retention and stability of the ove

  14. Implant supported overdentures--the Copenhagen experience

    DEFF Research Database (Denmark)

    Gotfredsen, K

    1997-01-01

    OBJECTIVES: To evaluate the functional and biological effect of implant-supported overdenture treatment in the lower jaw. METHODS AND MATERIALS: Thirty-two patients were consecutively treated with Astra Tech implants in the lower jaw for retaining overdentures. All implants had a diameter of 3.5 ...

  15. Attachment alternatives in implant-supported overdentures

    OpenAIRE

    Aktaş, Güliz; CANAY, Şenay

    2015-01-01

    Severe resorption of the alveolar ridges often makes it very difficult for patients to wear conventional dentures due to the lack of retention and stability of the dentures. Implant-supported overdentures offer edentulous patients a better retained and more stable prosthesis resulting in improved chewing ability and patient satisfaction compared against conventional complete dentures. There exist various attachment systems to be used with overdenture prostheses and are available in the market...

  16. Treatment Outcome and Patient Satisfaction with Two Adjacent Implant-Supported Restorations in the Esthetic Zone

    NARCIS (Netherlands)

    Tymstra, Nynke; Meijer, Henny J. A.; Stellingsma, Kees; Raghoebar, Gerry M.; Vissink, Arjan

    2010-01-01

    The purpose of this study was to evaluate the clinical and radiographic parameters as well as the esthetic outcome of two adjacent implant-supported restorations and the surrounding peri-implant mucosa in the maxillary esthetic zone. Ten patients were treated with two adjacent implants in the anteri

  17. Survival of Implant-supported Fixed Partial Prostheses with Cantilevers: A Retrospective Analysis%悬臂梁式种植固定义齿的回顾性研究

    Institute of Scientific and Technical Information of China (English)

    张震; 李影; 陈菲; 谢超; 宋应亮; 李德华

    2013-01-01

    目的:评价悬臂梁式种植固定义齿的长期临床效果.方法:采用回顾性研究方法,收集2005-01-2011-06,在我科室采用悬臂梁式种植固定义齿修复58例患者(60个修复体,共103枚种植体)的临床及影像学资料.记录种植体的失败个数、修复体失败个数、边缘骨吸收情况、机械及生物并发症情况.结果:随访期内无种植体失败,有3个修复体失败.种植体7年累计存留率100%,修复体7年累计存留率为92.3%.随访期内并未见严重的边缘骨吸收,近悬臂端种植体周边缘骨吸收为(0.08±0.12)mm,远悬臂端种植体周边缘骨吸收为(0.09±0.14)mm.8个修复体(13%)、14枚种植体(14%)发生生物学并发症,11个修复体(18.3%)出现机械并发症.结论:本研究初步证实悬臂梁式种植固定义齿的修复方式临床效果是可靠的,可作为临床种植设计的一个可选方案.因较高的机械并发症,在选择螺丝固位方式时需加以注意.%Objective:To evaluate the long-term clinical and radiographic outcomes of implant-supported fixed partial dentures with cantilevers. Methods: The clinical and radiographic data of 103 implants-supported 60 fixed dentures with cantilevers in 58 patients were collected from January 2005 to June 2011 and retrospectively studied. Complication and failure of implants and/or prosthesis, peri -implant marginal bone loss, biological and technical complications were evaluated. Results: No implant failure was observed during the follow-up period. 3 prostheses were failed. The 7-year cumulative survival rate was 100% for implant-based analysis, and 92.3% for prostheses-based analysis. The mean peri-implant bone loss for implants mesial to cantilevers was (0.08±0.12) mm and (0.09 ±0.14) mm for implants distal to cantilever. 8 (13%) prostheses and 14 (14%) implants were exposed to biological complications, where as 11 (18.3%) prostheses were involved in technical complications. Conclusion: The

  18. [Analysis of the effect of contact strength on three-dimensional displacement of an implant-supported fixed bridge under axial-concentrated load using digital laser speckle photography].

    Science.gov (United States)

    Wang, Jun; Peng, Zhenzhen; Li, Aijie; Xu, Zujie; Chen, Xinmin

    2013-12-01

    The purpose of this study was to investigate the effect of four kinds of different contact strength on the three-dimensional displacement of an implant-supported fixed bridge using digital laser speckle photography method. An in vitro model of beagle mandible with an implant-supported fixed bridge in its right premolar region was developed. The bridge was Au-Pt metal-ceramic. The contact was recovered to four different tightnesses, named 0, 1, 2, and 3. Different axial concentrated static load was applied to abutments and bridge respectively. The three-dimensional displacement of the implant-supported fixed bridge was measured using digital laser speckle photographic method. The results demonstrated that the influence of contact tightness was mainly on the mesio-distal and buccal lingual parts. When the contact tightness reached number 3, the regularity of displacement distribution was changed. The present study proved that digital laser speckle photography was an effective method of measuring the micro-displacement. One of the criterions of contact recovering decreased the implant displacement effectively without changing the regularity of displacement distribution.

  19. A systematic review of implant-supported maxillary overdentures after a mean observation period of at least 1 year

    NARCIS (Netherlands)

    Slot, Wim; Raghoebar, Gerry M.; Vissink, Arjan; Slater, James J. Huddleston; Meijer, Henny J. A.

    2010-01-01

    P>Aim The aim of the present systematic review of implant-supported maxillary overdentures was to assess the survival of implants, survival of maxillary overdentures and the condition of surrounding hard and soft tissues after a mean observation period of at least 1 year. Material and methods MEDLIN

  20. Remote Sensing Efficiency for Urban Analysis of Mecca and Surrounds

    Science.gov (United States)

    Imam, Ayman; Alhaddad, Bahaa; Roca, Josep

    2016-06-01

    Situated in the southwest of Saudi Arabia, Mecca is considered the spiritual capital of one and a half billion worldwide Muslims. The city is visited by millions of pilgrims every year. It has undergone significant changes in land cover (LC) since the government first embarked on a series of ambitious development projects 20 years ago to accommodate the growing number of pilgrims and citizens. The main objective of our study is to detect, identify, analyze and measure the evolving land cover and urban morphology composition from multi-temporal satellite images. To characterize the morphological change during a period of twenty years, four satellite images, acquired in 1998 by Landsat TM and in 2003, 2008 and 2013 by Landsat ETM+, were classified into five main categories: Urban, Street, Soil and Vegetation. In addition, DEM has been extracted and included as Mountain. Change detection (CD) analysis is applied using post-classification comparison and GIS. As part of the study, morphological index, such as, Entropy is included for better understanding of urban structures behaviour. Mecca and its surroundings show a noticeable increase in urban and vegetation cover. Urban cover (UC) changes were divided into five radial directions: Northeast, Southeast, Southwest, East, and Northwest. These changes are influenced by mountain ranges surrounding the city and the highways. These revelations can play a significant role towards future planning and development activities, which may further promote urban growth.

  1. REMOTE SENSING EFFICIENCY FOR URBAN ANALYSIS OF MECCA AND SURROUNDS

    Directory of Open Access Journals (Sweden)

    A. Imam

    2016-06-01

    Full Text Available Situated in the southwest of Saudi Arabia, Mecca is considered the spiritual capital of one and a half billion worldwide Muslims. The city is visited by millions of pilgrims every year. It has undergone significant changes in land cover (LC since the government first embarked on a series of ambitious development projects 20 years ago to accommodate the growing number of pilgrims and citizens. The main objective of our study is to detect, identify, analyze and measure the evolving land cover and urban morphology composition from multi-temporal satellite images. To characterize the morphological change during a period of twenty years, four satellite images, acquired in 1998 by Landsat TM and in 2003, 2008 and 2013 by Landsat ETM+, were classified into five main categories: Urban, Street, Soil and Vegetation. In addition, DEM has been extracted and included as Mountain. Change detection (CD analysis is applied using post-classification comparison and GIS. As part of the study, morphological index, such as, Entropy is included for better understanding of urban structures behaviour. Mecca and its surroundings show a noticeable increase in urban and vegetation cover. Urban cover (UC changes were divided into five radial directions: Northeast, Southeast, Southwest, East, and Northwest. These changes are influenced by mountain ranges surrounding the city and the highways. These revelations can play a significant role towards future planning and development activities, which may further promote urban growth.

  2. Mechanical performance of implant-supported posterior crowns

    NARCIS (Netherlands)

    P. de Kok; C.J. Kleverlaan; N. de Jager; R. Kuijs; A.J. Feilzer

    2015-01-01

    Statement of problem The fracture of implant-supported restorations, especially of the veneering layer, is a common problem in dentistry. Monolithic ceramic or resin restorations might help solve this problem. Purpose The purpose of this in vitro study was to obtain additional insight into the risk

  3. Occlusal wear of provisional implant-supported restorations

    NARCIS (Netherlands)

    Santing, Hendrik J.; Kleverlaan, Cornelis J.; Werner, Arie; Feilzer, Albert J.; Raghoebar, Gerry M.; Meijer, Henny J. A.

    2015-01-01

    BACKGROUND: Implant-supported provisional restorations should be resistant to occlusal wear. PURPOSE: The purpose of this laboratory study was to evaluate three-body wear of three indirect laboratory composite resins, five chair side bis-acryl resin-based materials, and two chair side methacrylate-b

  4. Occlusal wear of provisional implant-supported restorations

    NARCIS (Netherlands)

    H.J. Santing; C.J. Kleverlaan; A. Werner; A.J. Feilzer; G.M. Raghoebar; H.J.A. Meijer

    2015-01-01

    Background Implant-supported provisional restorations should be resistant to occlusal wear. Purpose The purpose of this laboratory study was to evaluate three-body wear of three indirect laboratory composite resins, five chair side bis-acryl resin-based materials, and two chair side methacrylate-bas

  5. The clinical success of tooth- and implant-supported zirconia-based fixed dental prostheses. A systematic review.

    Science.gov (United States)

    Le, M; Papia, E; Larsson, C

    2015-06-01

    The aim was to make an inventory of the current literature on the clinical performance of tooth- or implant-supported zirconia-based FDPs and analyse and discuss any complications. Electronic databases, PubMed.gov, Cochrane Library and Science Direct, were searched for original studies reporting on the clinical performance of tooth- or implant-supported zirconia-based FDPs. The electronic search was complemented by manual searches of the bibliographies of all retrieved full-text articles and reviews, as well as a hand search of the following journals: International Journal of Prosthodontics, Journal of Oral Rehabilitation, International Journal of Oral & Maxillofacial Implants and Clinical Oral Implants Research. The search yielded 4253 titles. Sixty-eight potentially relevant full-text articles were retrieved. After applying pre-established criteria, 27 studies were included. Twenty-three studies reported on tooth-supported and 4 on implant-supported FDPs. Five of the studies were randomised, comparing Y-TZP-based restorations with metal-ceramic or other all-ceramic restorations. Most tooth-supported FDPs were FDPs of 3-5 units, whereas most implant-supported FDPs were full arch. The majority of the studies reported on 3- to 5-year follow-up. Life table analysis revealed cumulative 5-year survival rates of 93.5% for tooth-supported and 100% for implant-supported FDPs. For tooth-supported FDPs, the most common reasons for failure were veneering material fractures, framework fractures and caries. Cumulative 5-year complication rates were 27.6% and 30.5% for tooth- and implant-supported FDPs, respectively. The most common complications were veneering material fractures for tooth- as well as implant-supported FDPs. Loss of retention occurred more frequently in FDPs luted with zinc phosphate or glass-ionomer cement compared to those luted with resin cements. The results suggest that the 5-year survival rate is excellent for implant-supported zirconia-based FDPs

  6. Electromyographic evaluation of mastication and swallowing in elderly individuals with mandibular fixed implant-supported prostheses

    Directory of Open Access Journals (Sweden)

    Giédre Berretin-Felix

    2008-04-01

    Full Text Available This study evaluated the effect of implant-supported oral rehabilitation in the mandible on the electromyographic activity during mastication and swallowing in edentulous elderly individuals. Fifteen patients aged more than 60 years were evaluated, being 10 females and 5 males. All patients were edentulous, wore removable complete dentures on both dental arches, and had the mandibular dentures replaced by implant-supported prostheses. All patients were submitted to electromyographic evaluation of the masseter, superior orbicularis oris muscles, and the submental muscles, before surgery and 3, 6 and 18 months postoperatively, using foods of different textures. The results obtained at the different periods were analyzed statistically by Kruskal-Wallis non-parametric test. Statistical analysis showed that only the masseter muscle had a significant loss in electromyographic activity (p<0.001, with a tendency of similar response for the submental muscles. Moreover, there was an increase in the activity of the orbicularis oris muscle during rubber chewing after treatment, yet without statistically significant difference. Mandibular fixed implant-supported prostheses in elderly individuals revealed a decrease in electromyographic amplitude for the masseter muscles during swallowing, which may indicate adaptation to new conditions of stability provided by fixation of the complete denture in the mandibular arch.

  7. Simplified custom impression post for implant-supported restorations.

    Science.gov (United States)

    Patras, Michael; Martin, William

    2016-05-01

    The esthetic outcome of an implant-supported restoration is greatly influenced by the relationship between the contours of the definitive prosthesis and the periimplant tissues. In this clinical technique, an implant analog holder and autopolymerizing acrylic resin were used to accurately register the soft-tissue transition zone created by the interim restoration and transfer it to the impression post during the definitive impression. PMID:26774317

  8. Patient satisfaction concerning implant-supported prostheses: an observational study

    OpenAIRE

    Bruno César de Vasconcelos GURGEL; Ana Luísa de Barros PASCOAL; Bruno Luiz Menezes de SOUZA; Poliana Medeiros Cunha DANTAS; Sheyla Christinne Lira MONTENEGRO; Angelo Giuseppe Roncalli da Costa OLIVEIRA; Calderon, Patrícia dos Santos

    2015-01-01

    The aim of this observational study was to assess the degree of patient satisfaction toward implant-supported prostheses. A questionnaire was used with two scales (one consisting of detailed adjectival and the other of numerical responses) regarding chewing, esthetics, speaking, comfort and overall satisfaction. The scales were administered to a sample of 147 patients treated with implants and prostheses. The data were submitted to the Kappa statistic and the Chi-square test to analyze the as...

  9. Biomechanical considerations on tooth-implant supported fixed partial dentures

    OpenAIRE

    Michalakis, Konstantinos X.; Calvani, Pasquale; Hirayama, Hiroshi

    2012-01-01

    This article discusses the connection of teeth to implants, in order to restore partial edentulism. The main problem arising from this connection is tooth intrusion, which can occur in up to 7.3% of the cases. The justification of this complication is being attempted through the perspective of biomechanics of the involved anatomical structures, that is, the periodontal ligament and the bone, as well as that of the teeth- and implant-supported fixed partial dentures.

  10. Split-Framework in Mandibular Implant-Supported Prosthesis

    Directory of Open Access Journals (Sweden)

    Danny Omar Mendoza Marin

    2015-01-01

    Full Text Available During oral rehabilitation of an edentulous patient with an implant-supported prosthesis, mandibular flexure must be considered an important biomechanical factor when planning the metal framework design, especially if implants are installed posterior to the interforaminal region. When an edentulous mandible is restored with a fixed implant-supported prosthesis connected by a fixed full-arch framework, mandibular flexure may cause needless stress in the overall restorative system and lead to screw loosening, poor fit of prosthesis, loss of the posterior implant, and patient’s discomfort due to deformation properties of the mandible during functional movements. The use of a split-framework could decrease the stress with a precise and passive fit on the implants and restore a more natural functional condition of the mandible, helping in the longevity of the prosthesis. Therefore, the present clinical report describes the oral rehabilitation of an edentulous patient by a mandibular fixed implant-supported prosthesis with a split-framework to compensate for mandibular flexure. Clinical Significance. The present clinical report shows that the use of a split-framework reduced the risk of loss of the posterior implants or screws loosening with acceptable patient comfort over the period of a year. The split-framework might have compensated for the mandibular flexure during functional activities.

  11. Stability analysis and support study on surroundings of finishing cut

    Energy Technology Data Exchange (ETDEWEB)

    Xu, J.; Miao, X.; Lu, A.; Xing, C. [CUMT, Jiangsu (China). College of Mineral and Energy Resources

    2003-09-01

    By means of finishing cut the trackless rubber-tried vehicle can directly go to the working face to remove the equipment. It can promote the efficiency in removing the equipment. Because of the finishing cut continuously affected by the dynamic pressure of face, it is important to find the reasonable position of the finishing cut and the proportion support. Based on the study of the ground pressure and the moving law of overlying strata during the terminal mining in sublevel caving face, the optimal position and the proportion support way of finishing cut were obtained using experiment with analog simulation and numerical simulation. This method can keep the stability for the surroundings of the finishing cut and lay the foundation for finishing the face quickly and safely. The engineering practice shows this technique is efficient and the significant social and economy benefit is obtained. 7 refs.,11 figs.

  12. Reliability analysis of tunnel surrounding rock stability by Monte-Carlo method

    Institute of Scientific and Technical Information of China (English)

    XI Jia-mi; YANG Geng-she

    2008-01-01

    Discussed advantages of improved Monte-Carlo method and feasibility aboutproposed approach applying in reliability analysis for tunnel surrounding rock stability. Onthe basis of deterministic parsing for tunnel surrounding rock, reliability computing methodof surrounding rock stability was derived from improved Monte-Carlo method. The com-puting method considered random of related parameters, and therefore satisfies relativityamong parameters. The proposed method can reasonably determine reliability of sur-rounding rock stability. Calculation results show that this method is a scientific method indiscriminating and checking surrounding rock stability.

  13. Impact of fixed implant supported prostheses in edentulous patients: protocol for a systematic review

    Science.gov (United States)

    López, Carolina S; Saka, Constanza H; Rada, Gabriel; Valenzuela, Daniela D

    2016-01-01

    Introduction Edentulism is a debilitating and irreversible condition described as the ‘final marker of disease burden for oral health’. Therapy with dental implants is being used on a large scale to replace missing teeth and to rehabilitate edentulous patients with overdentures and implant supported fixed dentures as a method of solving the problem of instability and lack of retention associated with conventional removable prostheses. Fixed implant supported prostheses are an alternative for implant rehabilitation treatment that allow patients to have new fixed teeth. They can be indicated in partial or total edentulous patients, and they can replace single teeth, or teeth and supporting tissues (hybrid prosthesis). They overcome the limitations of conventional dentures, increasing stability and retention, providing functional and psychological advantages for the patients. Methods and analysis We will electronically search for randomised controlled trials evaluating the effects of fixed implant supported prostheses in edentulous patients in the following databases: Pubmed/MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials. We will also try to obtain literature screening references of included studies, searching for trial protocols in the WHO International Clinical Trials Registry Platform, reviewing International Team for Implantology conference proceedings and searching for non-published studies through Open Gray. Two researchers will independently undertake selection of studies, data extraction and assessment of the quality of the included studies. Data synthesis and subgroup analyses will be performed using special Review Manager software. Data will be combined in a meta-analysis using a random effects model. Results The results will be presented as risk ratios for dichotomous data, and as mean difference or standardised mean difference for continuous data. Ethics and dissemination No ethics approval is considered necessary. The results

  14. Patient satisfaction concerning implant-supported prostheses: an observational study

    Directory of Open Access Journals (Sweden)

    Bruno César de Vasconcelos GURGEL

    2015-01-01

    Full Text Available The aim of this observational study was to assess the degree of patient satisfaction toward implant-supported prostheses. A questionnaire was used with two scales (one consisting of detailed adjectival and the other of numerical responses regarding chewing, esthetics, speaking, comfort and overall satisfaction. The scales were administered to a sample of 147 patients treated with implants and prostheses. The data were submitted to the Kappa statistic and the Chi-square test to analyze the association between dependent and independent variables. High degrees of satisfaction (greater than 91% were found for all categories evaluated, regardless of gender, age, number of implants or type of prosthesis. “Comfort” was associated significantly with the number of implants (p = 0.038, and “speaking” was associated significantly with the type of prosthesis (p = 0.029. Positive agreement was found between the scales for all categories evaluated, without statistically significant differences regarding respondent preference (p = 0.735. Patients treated with implant-supported prostheses were highly satisfied with the treatment.

  15. Marginal fit of implant-supported all-ceramic zirconia frameworks.

    Science.gov (United States)

    Zaghloul, Hanaa Hassan; Younis, Jihan Farouk

    2013-08-01

    This study evaluated the effect of fabrication techniques and cyclic loading on the vertical marginal fit of implant-supported fixed partial denture (FPD) frameworks. Thirty implant-supported 3-unit FPD frameworks were fabricated on a model system, divided into 3 equal groups (n = 10). The first group (control) was constructed from base metal alloy; the other 2 test groups were constructed from all-ceramic zirconia using a computer-aided design/computer-aided manufacturing (CAD/CAM) Cerec 3 system and a copy milling (Zirkonzahn) system. A cyclic load of 200 N was applied to each framework for up to 50,000 cycles. Linear measurements were made in micrometers of the vertical gap between the framework and the implant-supported abutment at 16 predetermined points before and after cyclic loading. The frameworks were viewed using scanning electron microscopy to inspect any fractographic features. One-way analysis of variance was performed to compare the marginal discrepancy values of the control and the 2 test groups and for each group; a t test was applied to determine whether significant changes in the fit were observed after cyclic loading (α = 0.05). The CAD/CAM group showed significantly higher marginal gap mean values (80.58 μm) than the Zirkonzahn and control groups (50.33 μm and 42.27 μm, respectively) with no significant difference. After cyclic loading, the CAD/CAM group recorded the highest marginal gap mean value (91.50 ± 4.260 μm) followed by control group (72.00 ± 2.795 μm); the Zirkonzahn group recorded the lowest marginal gap (65.37 ± 6.138 μm). Cyclic loading significantly increased the marginal gap mean values in the control group only. A marginal chip was observed in one of the CAD/CAM ceramic frameworks. Within the limitations of this study, the fabrication technique influenced the marginal fit of the implant-supported 3-unit FPD frameworks. Cyclic loading failed to change the fit of all-ceramic zirconia frameworks, whereas significant

  16. Bone's responses to different designs of implant-supported fixed partial dentures.

    Science.gov (United States)

    Rungsiyakull, Chaiy; Chen, Junning; Rungsiyakull, Pimduen; Li, Wei; Swain, Michael; Li, Qing

    2015-04-01

    This paper explores the biomechanics and associated bone remodeling responses of two different abutment configurations, namely implant-implant-supported versus tooth-implant-supported fixed partial dentures. Two 3D finite element analysis models are created based upon computerized tomography data. The strain energy density induced by occlusal loading is used as a mechanical stimulus for driving the bone remodeling. To measure osseointegration and stability during healing, a resonance frequency analysis is conducted. At the second premolar peri-implant region, overloading resorption around the neck of implant is identified in both the models over the first 12 months. Stress-shielding around the edentulous region is also observed in both the models with a greater resorption rate found in the implant-implant case. The remodeling and resonance frequency analyses reveal that the tooth-implant scheme offers a higher degree of osseointegration. The remodeling procedure is expected to provide prosthodontists with a modeling tool to assess possible long-term clinical outcomes. PMID:25209424

  17. Implant-supported overdentures: the ZAAG attachment system.

    Science.gov (United States)

    Davidoff, S R

    1997-11-01

    It has been amply demonstrated during the last decade that there are significant advantages to implant-supported overdentures beyond conventional complete dentures. Several attachment systems exist for connecting the overdenture to the implants, and practically all of them present notable benefits to the patients. This article discusses the use of the Zest Anchor Advanced Generation (ZAAG). This system, an outgrowth from the original Zest attachment, uses both individual implant attachments and bar attachments, and is compatible with all major implant systems. In addition to the retention, stability, and resiliency the ZAAG implant attachment system provides, it has the advantage of placing the resistance force of the attachment close to the implant body. PMID:9533347

  18. Effect of veneering material on the deformation suffered by implant-supported fixed prosthesis framework

    Directory of Open Access Journals (Sweden)

    Antônio Francisco GRANDO

    2014-06-01

    Full Text Available Knowing how stresses are dissipated on the fixed implant-supported complex allows adequate treatment planning and better choice of the materials used for prosthesis fabrication. Objectives: The aim of this study was to evaluate the deformation suffered by cantilevered implant-supported fixed prostheses frameworks cast in silver-palladium alloy and coated with two occlusal veneering materials: acrylic resin or porcelain. Material and Methods: Two strain gauges were bonded to the inferior surface of the silver-palladium framework and two other were bonded to the occlusal surface of the prosthesis framework covered with ceramic and acrylic resin on each of its two halves. The framework was fixed to a metallic master model and a 35.2 N compression force was applied to the cantilever at 10, 15 and 20 mm from the most distal implant. The measurements of deformation by compression and tension were obtained. The statistical 2-way ANOVA test was used for individual analysis of the experiment variables and the Tukey test was used for the interrelation between all the variables (material and distance of force application. Results: The results showed that both variables had influence on the studied factors (deformation by compression and tension. Conclusion: The ceramic coating provided greater rigidity to the assembly and therefore less distortion compared with the uncoated framework and with the resin-coated framework. The cantilever arm length also influenced the prosthesis rigidity, causing higher deformation the farther the load was applied from the last implant.

  19. A meta-analysis of effectiveness of an implant-supported mandibular overdenture retained with a ball attachment%种植体支持球帽附着体固位下颌覆盖全口义齿应用效果的Meta分析

    Institute of Scientific and Technical Information of China (English)

    黄岩; 郭娜

    2014-01-01

    with a bal attachment and other control methods for dentures. The time limit was from database creation to February 2014. Two researchers independently completed literature screening according to inclusion and exclusion criteria, data extraction and quality assessment. RevMan 5.1 software was used for meta-analysis. RESULTS AND CONCLUSION: There were 10 studies included in result analysis, including 7 from China and 3 from other countries. Analysis results showed that statistical heterogeneity was remarkable in included studies, and there was no significant difference in patient’s satisfaction, clinical and objective indicators, and complications, suggesting that this approach continues to be explored in clinic. The implant-supported bal attachment-retained mandibular overdenture is relatively expensive, which is identical with the current research progress that is in the exploration stage worldwide. Due to the limited quantity and quality of included studies, the conclusions of this systematic review only provide references for clinical practice and research. The implant-supported bal attachment-retained mandibular overdenture stil needs further exploration and improvement.

  20. Stability classification model of mine-lane surrounding rock based on distance discriminant analysis method

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wei; LI Xi-bing; GONG Feng-qiang

    2008-01-01

    Based on the principle of Mahalanobis distance discriminant analysis (DDA) theory, a stability classification model for mine-lane surrounding rock was established, including six indexes of discriminant factors that reflect the engineering quality of surrounding rock: lane depth below surface, span of lane, ratio of directly top layer thickness to coal thickness, uniaxial comprehensive strength of surrounding rock, development degree coefficient of surrounding rock joint and range of broken surrounding rock zone. A DDA model was obtained through training 15 practical measuring samples. The re-substitution method was introduced to verify the stability of DDA model and the ratio of mis-discrimination is zero. The DDA model was used to discriminate3 new samples and the results are identical with actual rock kind. Compared with the artificial neural network method and support vector mechanic method, the results show that this model has high prediction accuracy and can be used in practical engineering.

  1. Comparison of Implant-Supported Crown Length Measured on Digitized Casts and Intraoral Radiographs

    NARCIS (Netherlands)

    Meijer, Henny J. A.; Telleman, Gerdien; Gareb, Chawan; Den Hartog, Laurens; Vissink, Arjan; Raghoebar, Gerry M.

    2012-01-01

    Correct measurement of crown length is important for calculating the crown-implant ratio. The aim of this study was to compare the length of implant-supported crowns measured on digitized casts and intraoral radiographs. Crown lengths were studied in 50 patients with 86 implant-supported crowns in t

  2. Numerical Analysis of Advanced Displacement in Construction Progress of Tunnel Excavation with Weak Surrounding Rock

    Directory of Open Access Journals (Sweden)

    Qian Zhang

    2013-07-01

    Full Text Available Analysis of advanced displacement in construction progress of tunnel excavation with weak surrounding rock is carried out by numerical method and comparison of model test result. In allusion to the problems of regional landslides and extruded large-deformation seriously impacting the stability of rock mass in construction process of large-section tunnel with weak surrounding rock, the elastic-plastic numerical simulation relying on Liangshui tunnel of Lan-Yu railroad is conducted on mechanical behaviors and deformation steric effect of tunnel construction and the calculation results are compared with the modeling data. The research results show that: the steric effect of excavation face is the dominant factor in the incidence of working face and the stress of surrounding rocks gradually releases from excavation face; the range of 0.5~1 times the cave diameter around rock mass in front of working face is the disturbance range and the key area of stabilization and reinforcement for wake surrounding rock. According to the analysis and construction practice, the supporting structure of large-section tunnel with weak surrounding rock should be established as soon as possible to control the displacement change of surrounding rock in the range of load-bearing ring, reduce disturbance and improve the self-bearing capability of surrounding rock. Because of the distinct excavation steric effect of weak surrounding rock, the secondary lining structure must be established in time to bear the later pressure and restrict the large displacement of surrounding rock. The research results can provide reliable basis for engineering stability control of analogous tunnels.

  3. Zirconia- versus metal-based, implant-supported abutments and crowns

    DEFF Research Database (Denmark)

    Hosseini, Mandana

    was to test the reliability and validity of six aesthetic parameters used at the Copenhagen Dental School to assess the aesthetic outcome of implant-supported restorations. The aims of study III and IV were to compare the influence of different abutment and crown materials on biological, biomechanical......To restore oral functions in patients with missing teeth, single-tooth implants are a well-documented treatment option. Along with high survival rates, aesthetic factors have become an important clinical outcome variable for evaluating treatment success of implant-supported restorations. Thus...... studies have reported on aesthetic, biological, biomechanical and patient-reported outcomes of implant-supported single-tooth restorations of various biomaterials. The aim of the present thesis was to investigate the clinical performance of zirconia-based implant-supported single-tooth restorations...

  4. Implant-supported hybrid prosthesis: Conventional treatment method for borderline cases

    OpenAIRE

    Egilmez, Ferhan; Ergun, Gulfem; Cekic-Nagas, Isil; Bozkaya, Suleyman

    2015-01-01

    An implant-supported hybrid prosthesis is an acrylic resin complete fixed dental prosthesis and supported by implants might be a solution in extreme cases that the need of the restoration for esthetics, function, lip support, and speech. This clinical report aims to present the esthetic and functional prosthetic rehabilitation of three borderline cases with implant-supported hybrid prostheses. Patient 1 (62-year-old man) and Patient 2 (61-year-old man) presented a chief complaint of a comprom...

  5. Impact of fixed implant supported prostheses in edentulous patients: protocol for a systematic review

    OpenAIRE

    López, Carolina S; Saka, Constanza H; Rada, Gabriel; Valenzuela, Daniela D

    2016-01-01

    Introduction Edentulism is a debilitating and irreversible condition described as the ‘final marker of disease burden for oral health’. Therapy with dental implants is being used on a large scale to replace missing teeth and to rehabilitate edentulous patients with overdentures and implant supported fixed dentures as a method of solving the problem of instability and lack of retention associated with conventional removable prostheses. Fixed implant supported prostheses are an alternative for ...

  6. Effect of veneering material on the deformation suffered by implant-supported fixed prosthesis framework

    OpenAIRE

    GRANDO, Antônio Francisco; Carlos Eduardo Edwards REZENDE; SOUSA, Edson Antônio Capello; RUBO, José Henrique

    2014-01-01

    Knowing how stresses are dissipated on the fixed implant-supported complex allows adequate treatment planning and better choice of the materials used for prosthesis fabrication. Objectives: The aim of this study was to evaluate the deformation suffered by cantilevered implant-supported fixed prostheses frameworks cast in silver-palladium alloy and coated with two occlusal veneering materials: acrylic resin or porcelain. Material and Methods: Two strain gauges were bonded to the inferior su...

  7. Analysis for interaction of supports and surrounding rock of gateways in Iongwall minging

    Institute of Scientific and Technical Information of China (English)

    伍永平

    2001-01-01

    Gateway supporting in long-wall mining has been a problem that restricts the mine production and safety, the paper sets up an interaction model between support and surrounding rock ( rock mass structure) and probes the elementary t.heory about ground pressure behaviors of gateway. Based on the analysis of supporting theories, some new viewpoints about gateways supporting and ground pressure controlling are put forward.

  8. Analysis for interaction of supports and surrounding rock of gateways in longwall minging

    Institute of Scientific and Technical Information of China (English)

    WU Yong-ping

    2001-01-01

    Gateway supporting in long-wall mining has been a problem that restri cts the mine production and safety, the paper sets up an interaction model betwe en support and surrounding rock (rock mass structure) and probes the elementary theory about ground pressure behaviors of gateway. Based on the analysis of supp orting theories, some new viewpoints about gateways supporting and ground pressu re controlling are put forward.

  9. Elements of implant-supported rehabilitation planning in patients with bruxism.

    Science.gov (United States)

    Sarmento, Hugo Ramalho; Dantas, Raquel Venâncio Fernandes; Pereira-Cenci, Tatiana; Faot, Fernanda

    2012-11-01

    The rehabilitation of partial or completely edentulous patients with implant-supported prostheses has been widely used, achieving high success rates. However, many studies consider the presence of bruxism as a contraindication for this treatment modality. The purpose of this study was to revise the literature and identify risk factors in implant-supported rehabilitation planning in subjects with bruxism. Available literature was searched through Medline, with no time limit, including only studies in English. Topics discussed were etiology of bruxism and its implications on dental implants, biomechanical considerations regarding the overload on dental implants, and methods to prevent the occurrence of overloads in implant-supported prostheses. The rehabilitation of bruxers using implant-supported prostheses, using implants with adequate length and diameter, as well as proper positioning seems to be a reliable treatment, with reduced risks of failure. Bruxism control through the use of a nightguard by rigid occlusal stabilization appliance relieved in the region of implants is highly indicated. Although it is clear that implant-supported rehabilitation of patients with bruxism requires adequate planning and follow-up, well-designed randomized controlled trials are needed to provide reliable evidence on the long-term success of this treatment modality. PMID:23172439

  10. Numerical analysis and field monitoring tests on shallow tunnels under weak surrounding rock

    Institute of Scientific and Technical Information of China (English)

    刘建华; 刘晓明; 张永杰; 肖庭

    2015-01-01

    The Jianpudong No. 4 tunnel is a shallow tunnel, which belongs to Shaoshan County scenic highway in Hunan province, China and whose surrounding rock is weak. According to its characteristics, the field monitoring tests and numerical analysis were done. The mechanical characteristics of shallow tunnels under weak surrounding rock and the stress−strain rule of surrounding rock and support were analyzed. The numerical analysis results show that the settlement caused by upper bench excavating accounts for 44% of the total settlement, and the settlement caused by tunnel upper bench supporting accounts for 56% of the total settlement. The maximum axial force of shotcrete lining is 177.2 kN, which locates in hance under the secondary lining. The maximum moment of shotcrete lining is 5.08 kN·m, which locates in the arch foot. The stress curve of steel arch has three obvious stages during the tunnel construction. The maximum axial force of steel arch is 297.4 kN, which locates in tunnel vault. The axial forces of steel arch are respectively 23.5 kN and−21.8 kN, which is influenced by eccentric compression of shallow tunnel and locates in hance. The results show that there is larger earth pressure in tunnel vault which is most unfavorable position of steel arch. Therefore, the advance support should be strengthened in tunnel vault during construction process.

  11. Strain development of implant-supported fixed prostheses copy milled from zirconia ceramic.

    Science.gov (United States)

    Karl, Matthias; Graef, Friedrich; Wichmann, Manfred

    2011-01-01

    The aim of this research was to quantify the strain development of three-unit implant-supported fixed partial dentures (ISFPDs) copy milled from zirconia ceramic. Three ISFPD groups (n = 10) were fabricated by means of casting, copy milling, and computer-aided design/computer-assisted manufacturing (CAD/CAM) to fit an in vitro model with two implants. During cementation of the restorations, the emerging strains were recorded using strain gauges attached to the cast material mesially and distally adjacent to the implants. Absolute mean strain development ranged from 85.39 Μm/m to 326.83 Μm/m at the different strain gauge locations. Fabrication method had a significant effect on strain development (multivariate analysis of variance, P = .011), with the cast restorations showing the highest strain development and the CAD/CAM-fabricated ISFPDs showing the lowest. Copy milling leads to ISFPs that are more precise than cast restorations but less precise than CAD/CAM-fabricated restorations. PMID:21909492

  12. Stress distribution in implant-supported prostheses using different connection systems and cantilever lengths: digital photoelasticity.

    Science.gov (United States)

    Goiato, Marcelo Coelho; Shibayama, Ricardo; Gennari Filho, Humberto; de Medeiros, Rodrigo Antonio; Pesqueira, Aldiéris Alves; dos Santos, Daniela Micheline; de Araújo, Cleudmar Amaral

    2016-01-01

    Photoelastic analysis was used to evaluate the biomechanical behaviour of implant-supported, double-screwed crowns with different connection systems and cantilever lengths. Three models were made in PL-2 photoelastic resin and divided into six groups, on the basis of the implant connection system (external hexagon [EH] or Morse taper [MT]), type of abutment (Mini Pilar [Neodent, Curitiba, Paraná, Brazil] or "UCLA") and number of crowns in the cantilever (one or two). The implant-prosthesis unit was placed in a circular polariscope. Occlusal surfaces of the crowns were subjected to 100-N loads in the axial and oblique (45°) directions in a universal testing machine (EMIC). Generated stresses were recorded and analysed qualitatively in a graphics program (Adobe Photoshop). Under axial loading, all of the groups had similar numbers of fringes, which were increased when the crowns were subjected to oblique loading. The highest number of fringes was found during oblique loading in the EH + Mini Pilar group. In conclusion, although the type of implant connection system did not have a direct influence on the stress distribution for axial loading, the cantilever length did have a direct influence on stress distribution. Models with two crowns in the cantilever showed more stress, with a greater concentration of force on the cervical part of the implant. PMID:26783652

  13. Stress distribution in implant-supported prostheses using different connection systems and cantilever lengths: digital photoelasticity.

    Science.gov (United States)

    Goiato, Marcelo Coelho; Shibayama, Ricardo; Gennari Filho, Humberto; de Medeiros, Rodrigo Antonio; Pesqueira, Aldiéris Alves; dos Santos, Daniela Micheline; de Araújo, Cleudmar Amaral

    2016-01-01

    Photoelastic analysis was used to evaluate the biomechanical behaviour of implant-supported, double-screwed crowns with different connection systems and cantilever lengths. Three models were made in PL-2 photoelastic resin and divided into six groups, on the basis of the implant connection system (external hexagon [EH] or Morse taper [MT]), type of abutment (Mini Pilar [Neodent, Curitiba, Paraná, Brazil] or "UCLA") and number of crowns in the cantilever (one or two). The implant-prosthesis unit was placed in a circular polariscope. Occlusal surfaces of the crowns were subjected to 100-N loads in the axial and oblique (45°) directions in a universal testing machine (EMIC). Generated stresses were recorded and analysed qualitatively in a graphics program (Adobe Photoshop). Under axial loading, all of the groups had similar numbers of fringes, which were increased when the crowns were subjected to oblique loading. The highest number of fringes was found during oblique loading in the EH + Mini Pilar group. In conclusion, although the type of implant connection system did not have a direct influence on the stress distribution for axial loading, the cantilever length did have a direct influence on stress distribution. Models with two crowns in the cantilever showed more stress, with a greater concentration of force on the cervical part of the implant.

  14. Individual lithium disilicate crowns in a full-arch, implant-supported rehabilitation: a clinical report.

    Science.gov (United States)

    Maló, Paulo; de Sousa, Sérgio Tavares; De Araújo Nobre, Miguel; Moura Guedes, Carlos; Almeida, Ricardo; Roma Torres, António; Legatheaux, João; Silva, António

    2014-08-01

    This clinical report presents the clinical outcome of a maxillary full-arch implant-supported fixed rehabilitation with lithium disilicate reinforced glass ceramic monolithic crowns opposing a mandibular metal-acrylic implant-supported fixed rehabilitation in a 62-year-old woman. Eight implants were successfully placed (four maxillary, four mandibular), and no complications occurred in the postoperative or maintenance periods. Six months after delivery, the maxillary and mandibular prostheses were found to be clinically, biologically, and mechanically stable, and the patient was satisfied with the esthetics and her ability to function. Although the present indications for the use of lithium disilicate are still restricted to tooth-borne restorations, it is possible to successfully rehabilitate edentulous patients through implant-supported fixed prostheses using lithium disilicate reinforced glass ceramic monolithic crowns.

  15. The periodontal prosthesis mode of transition to an implant-supported dentition.

    Science.gov (United States)

    Hunt, Peter; Norkin, Frederic; Serrano, Julian

    2006-01-01

    In recent years, implant-supported reconstructions have become a welcome alternative to dentures for those who have lost their natural dentition. While the benefits of the final implant-supported reconstruction may be obvious, the planning and execution of therapy to achieve this result may be bewildering to many dentists. Four main modes of transfer have evolved: an uncontrolled or "haphazard" transition; the traditional "dentures first" mode, an immediate transition, and a staged transition. This article proposes an additional mode of transition called periodontal prosthesis, which has the potential to make the transition process smoother and more predictable while providing optimal retention of alveolar supporting structures and generating optimal esthetics.

  16. Implant-connected versus tooth-connected implant-supported partial dentures: 2-year clinical and radiographic comparative evaluation.

    Science.gov (United States)

    Mostafa, Tamer Mohamed; El-Sheikh, Mohamed M; Abd El-Fattah, Fadel

    2015-01-01

    The purpose of this study was to clinically and radiographically compare implant-connected and tooth-connected implant-supported fixed-detachable mandibular partial dentures. Twenty partially edentulous patients (age range: 25 to 50 years) with mandibular Kennedy Class II configurations were equally divided into two groups receiving a three-unit, fixed-detachable, screw-retained partial denture. Group 1 comprised patients with unilateral missing mandibular molars and premolars. Two implants were placed at the mandibular first premolar and first molar areas. Group 2 comprised patients with missing mandibular molars and second premolars. An implant was placed at the mandibular first molar area, the first premolar was prepared, and a coping was cemented to the tooth with permanent cement. Each case was evaluated clinically and radiographically at baseline (partial denture insertion) and after 6, 12, and 24 months. Data were collected and statistically analyzed using repeated-measures one-way and two-way analysis of variance tests. There was no statistically significant difference between the two groups (P > .05). The implant-tooth-supported prosthesis provided an equally predictable treatment option compared to the totally implant-supported prosthesis in terms of implant survival and loss of marginal bone. PMID:25909533

  17. Water analysis from wells in Ezeiza and surrounding areas. Dissolved uranium

    International Nuclear Information System (INIS)

    In order to give an answer to the different social sectors, we sampled water from previously existing wells that reaches the Puelche aquifer. The uranium concentration was determined in these samples to obtain a preliminary checkup of water quality situation. For the analysis we considered the samples obtained inside the CAE as well as those sampled in the surrounding areas as Monte Grande, Claypole and Burzaco. The results show a correlation between the amount of dissolved salts and the presence of dissolved uranium. (author)

  18. Evaluation of the therapeutic efficiency of mandibular anterior implant-supported fixed bridges with cantilevers

    Institute of Scientific and Technical Information of China (English)

    WU Min-jie; WANG Xiao-jing; ZOU Li-dong; XU Wei-hua; ZHANG Xiang-hao

    2013-01-01

    Background Dental implant technology has developed rapidly in recent years.However,the use of implant-supported fixed bridges with cantilevers has been controversial.The purpose of this study was to evaluate the clinical results of the mandibular anterior implant-supported fixed bridges with a cantilever.Method Thirty-three patients (15 males,18 females; mean age,42.6 years; range 20-54 years) with two missing anterior mandibular teeth had single implant-supported fixed bridges with a cantilever.Clinical examination was recorded and radiographs were taken.The mean duration of follow-up was 30 months (15-44 months).Results All implants survived.Loosening or fracture of the prosthesis was not observed.All patients were satisfied with the treatment.The mean bone resorption values after 12,24,and 36 months of implant loading were 0.94,1.18 and 1.35 mm respectively.The changes of gingival papilla height ranged from 0 to 0.5 mm.There was significant difference between 1-year and 2 or 3 years restoration groups regarding the average gingival height changes (P <0.05).Conclusion After careful and precise selection of patients,restoration with a single implant-supported fixed bridge with a cantilever can be recommended if two anterior mandibular teeth are missing.

  19. Rehabilitation with implant-supported overdentures in total edentulous patients: A review

    Science.gov (United States)

    Segura-Andrés, Gustavo; Faus-López, Joan; Agustín-Panadero, Rubén

    2013-01-01

    Objectives: The main aim of this review article is to discuss implant-supported overdentures (ISOs) as treatment in edentulous patients. Besides, we will try to discuss among the different treatment options in such patients and to analyze their validity when ISOs are compared with other clinical modalities. At the same time, we will try to suggest clinical guidelines supported by current clinical studies. Material and methods: We performed a Medline search and review of pertinent articles on the mentioned subject from 1986 to 2011. As a searching strategy, we used the following words: implant-supported overdentures, attachment systems, Locator attachment, cantilever, fixed prosthesis. Results and conclusions: Implant-supported overdentures constitute an accurate and predictable treatment option and achieve a higher patients’ satisfaction. This type of treatment constitutes a cheaper treatment than fixed prostheses and in some patients, with loss of lip support or with an interoclusal space larger than 15 mm, the choice of implant-supported overdentures seems to prevent future aesthetic or phonetic problems. Key words:Overdentures, implant occlusion, implant rehabilitation, total edentulous rehabilitation, fixed prosthesis. PMID:24455093

  20. Mechanical self-performed oral hygiene of implant supported restorations: a systematic review

    NARCIS (Netherlands)

    A. Louropoulou; D.E. Slot; F. van der Weijden

    2014-01-01

    A systematic review of self-performed oral hygiene practices for optimal maintenance of dental implant-supported restorations reveals a lack of evidence to support best practices. BACKGROUND: The standard of the patients' home care is a key factor for long term stability of dental implants and the p

  1. Prevalence of complications after the oral rehabilitation with implant-supported hybrid prostheses

    Science.gov (United States)

    Almendros-Marqués, Nieves; Gay-Escoda, Cosme

    2012-01-01

    Objectives: Assess the main problems referred by the patients and observed by the professionals after the bucodental rehabilitation with an implant-supported hybrid prothesis. Patient and Methods: A retrospective study was carried out in which there were 43 patients included who were visited in the Department of Oral Surgery and Orofacial Implantology of University of Barcelona Dental School for one year. An oral rehabilitation with an implant-supported hybrid prosthesis was made to those patients. The following variables were registered: age, gender, number of inserted implants, type of implant and principal problems produced by the hybrid prosthesis. Results: The rehabilitation with an implant supported hybrid prosthesis was only performed in 43 of 116 cases treated in one year (January, 2006 to January, 2007). They were 26 men and 17 women of ages between 37 and 74 years, being the rate age of 56,5 years. The main complication recorded was the mucositis, associated frequently with a difficulty to carry a correct oral hygiene and to an overextention of the tail of resin of the prosthesis. Other observed problems were the peri-implantitis, the break of the acrylic teeth and the loss of some of the prosthetic screws. Conclusions: The most frequent complication after the laying of an implant supported hybrid prosthesis was the mucositis, associated mainly with a prosthetic tail too long and to the consequent difficulty of carrying a correct oral hygiene. In spite of the high prevalence of observed complications, most of them were mild and resolved on subsequent visits. Key words: Implant supported hybrid prosthesis, complications and prosthetic fails. PMID:21743427

  2. A 1-year randomised controlled trial comparing zirconia versus metal-ceramic implant supported single-tooth restorations

    DEFF Research Database (Denmark)

    Hosseini, Mandana; Worsaae, Nils; Schiodt, Morten;

    2011-01-01

    To compare the biological, technical and aesthetic outcomes of single implant-supported all-ceramic versus metal-ceramic crowns.......To compare the biological, technical and aesthetic outcomes of single implant-supported all-ceramic versus metal-ceramic crowns....

  3. A 1-year randomised controlled trial comparing zirconia versus metal-ceramic implant supported single-tooth restorations

    DEFF Research Database (Denmark)

    Hosseini, Mandana; Worsaae, Nils; Schiødt, Morten;

    2011-01-01

    PURPOSE: To compare the biological, technical and aesthetic outcomes of single implant-supported all-ceramic versus metal-ceramic crowns. MATERIALS AND METHODS: Thirty-six patients with premolar agenesis were randomly treated with 38 all-ceramic (AC) and 37 metal-ceramic (MC) implant-supported si...

  4. Nonlinear Progressive Failure Analysis of Surrounding Rock System Based on Similarity Theory

    Directory of Open Access Journals (Sweden)

    Zhao Y.

    2016-01-01

    Full Text Available Nonlinear progressive failure study of surrounding rock is important for the stability analysis of underground engineering projects. Taking a deep-buried tunnel in Chongqing as an example, a three dimensional(3-D physical model was established based on similarity theory. To satisfy similarity requirement of physical–mechanical properties, such as elastic modulus, compressive strength and Poisson ratio, physical model materials were developed. Using full inner-spy photograph technology, the deformation and failure process of rock were studied under the situation of independent and combined action of anchor, shotcrete and reinforcing mesh. Based on experimental results, the interaction mechanism between rock and support structure under high stress was investigated.

  5. Independent Component Analysis of Water Storage Changes Interpretation over Tibetan Plateau and Its Surrounding Areas

    Directory of Open Access Journals (Sweden)

    WEN Hanjiang

    2016-01-01

    Full Text Available We first use the independent component analysis (ICA method to decompose the water storage changes derived from 132 months (2003-01—2013-12 gravity recovery and climate experiment (GRACE measurements, and then compare the results with those from NOAH and WGHM hydrological models. The comparison results of components show that the first principal components from the water storage changes and hydrological models agree well, and the correlation coefficients are 0.884 and 0.877 respectively. It shows that GRACE derived water storage changes and hydrological models over Tibetan Plateau and its surrounding areas have a strong consistency. For spatial pattern, the amplitudes of GRACE-derived water storage changes are larger than that of hydrological models, which may be caused by the groundwater changes included in the GRACE-derived water storage changes.

  6. A Numerical Analysis on Freezing Behavior of Flowing Water inside a Pipe Cooled from Surroundings

    Science.gov (United States)

    Chiba, Ryoichi; Izumi, Masaaki

    A freezing phenomenon in forced convectional flow inside a pipe is investigated numerically in this paper .The numerical analysis is carried out to assess the transient freezing behavior of flowing water inside a pipe cooled from surroundings in consideration of pressure drop caused by the freezing. The finite element technique is applied to solve the equations of motion and energy transport for laminar flow. The numerical model attempts to capture the solid-fluid interface on a fixed computational grid. The correlations among cooling conditions of pipe, velocity and temperature of water at the inlet, and location at which the freezing starts are examined to show the critical velocity to avoid freezing. In addition, under the condition that pressure remains constant at the inlet, the period in which the pipe is not blockaded by ice is calculated. The period is illustrated with some dimensionless parameters to predict the conditions under which blockage occurs within a given time.

  7. Multifractal analysis of earthquakes in Kumaun Himalaya and its surrounding region

    Indian Academy of Sciences (India)

    P N S Roy; S K Mondal

    2012-08-01

    Himalayan seismicity is related to continuing northward convergence of Indian plate against Eurasian plate. Earthquakes in this region are mainly caused due to release of elastic strain energy. The Himalayan region can be attributed to highly complex geodynamic process and therefore is best suited for multifractal seismicity analysis. Fractal analysis of earthquakes (mb ≥ 3.5) occurred during 1973–2008 led to the detection of a clustering pattern in the narrow time span. This clustering was identified in three windows of 50 events each having low spatial correlation fractal dimension () value 0.836, 0.946 and 0.285 which were mainly during the span of 1998 to 2005. This clustering may be considered as an indication of a highly stressed region. The Guttenberg Richter -value was determined for the same subsets considered for the estimation. Based on the fractal clustering pattern of events, we conclude that the clustered events are indicative of a highly stressed region of weak zone from where the rupture propagation eventually may nucleate as a strong earthquake. Multifractal analysis gave some understanding of the heterogeneity of fractal structure of the seismicity and existence of complex interconnected structure of the Himalayan thrust systems. The present analysis indicates an impending strong earthquake, which might help in better hazard mitigation for the Kumaun Himalaya and its surrounding region.

  8. Numerical analysis of tunnel reinforcing influences on failure process of surrounding rock under explosive stress waves

    Institute of Scientific and Technical Information of China (English)

    ZUO Yu-jun; TANG Chun-an; ZHU Wan-cheng; LI Di-yuan; LI Shu-cai

    2008-01-01

    Based on mesoscopic damage mechanics, numerical code RFPA2D (dynamic edition) was developed to analyze the influence of tunnel reinforcing on failure process of surrounding rock under explosive stress waves. The results show that the propagation phenomenon of stress wave in the surrounding rock of tunnel and the failure process of surrounding rock under explosive stress waves are reproduced realistically by using numerical code RFPAED; from the failure process of surrounding rock,the place at which surrounding rock fractures is transferred because of tunnel reinforcing, and the rockfall and collapse caused by failure of surrounding rock are restrained by tunnel reinforcing; furthermore, the absolute values of peak values of major principal stress, and the minimal principal stress and shear stress at center point of tunnel roof are reduced because of tunnel reinforcing, and the displacement at center point of tunnel roof is reduced as well, consequently the stability of tunnel increases.

  9. Photoelastic stress analysis in mandibular bone surrounding bar-clip overdenture implants

    Directory of Open Access Journals (Sweden)

    Mônica Nogueira Pigozzo

    2014-01-01

    Full Text Available The aim of this in vitro study was to evaluate, using the photoelastic analysis method, the stress distribution in mandibular bone surrounding a bar-clip overdenture when 2 implant angulations were simulated. Two mandibular photoelastic models were manufactured, with 2 implants embedded in the interforaminal region: model 1 - PAPI, a photoelastic analysis model with parallel implants; and model 2 - PAAI, a photoelastic analysis model with angled implants. A bar-clip retention system and an overdenture were positioned over the implants, and loads of 1.0, 2.0 and 3.0 bars were applied. The resultant stresses that developed in the supporting structure were photoelastically monitored and were recorded photographically. The results showed that there were no similarities in the areas of stress among the photoelastic resin models when the angulation of the implants was evaluated. Model 1 - PAPI presented a higher stress concentration at the implant apex, while in model 2 - PAAI, there were higher stress concentrations on the mesial and distal implant faces. Within the limitations of this study, it was concluded that the PAPI photoelastic model demonstrated better stress transfer compared to the PAAI model, since the forces oriented along the axis were better absorbed by the bone.

  10. In vivo study of the wear of a reinforced composite used to cover implant-supported frameworks.

    Science.gov (United States)

    David, Susana; Del Rio, Jaime; Celemín, Alicia; Serrano, Carlos

    2009-01-01

    The goal of this study was to research the wear shown by a material (Cristobal+) offered as an alternative to ceramics in the covering of an implant-supported fixed prosthesis. Twenty-six active cusps were used in this study; the control group consisted of 12 cusps adjacent to restorations composed of Cristobal+. Five images were obtained from each sample and analyzed using computer software that creates an arch along each cusp, so each image gives the value of the radius described by that arch. If a sample showed any sign of wear, the values for the successive radii would be increasingly larger since a flattened arch would produce a larger radius. An analysis of the paired Student t test was applied. After assessing the results, a statistically significant difference in wear was noted (P Cristobal+ reinforced composite was greater than that of the natural adjacent cusps.

  11. The Analysis of Surrounding Structure Effect on the Core Degradation Progress with COMPASS Code

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Jun Ho; Son, Dong Gun; Kim, Jong Tae; Park, Rae Jun; Kim, Dong Ha [KAERI, Daejeon (Korea, Republic of)

    2015-05-15

    In line with the importance of severe accident analysis after Fukushima accident, the development of integrated severe accident code has been launched by the collaboration of three institutes in Korea. KAERI is responsible to develop modules related to the in-vessel phenomena, while other institutes are to the containment and severe accident mitigation facility, respectively. In the first phase, the individual severe accident module has been developed and the construction of integrated analysis code is planned to perform in the second phase. The basic strategy is to extend the design basis analysis codes of SPACE and CAP, which are being validated in Korea for the severe accident analysis. In the first phase, KAERI has targeted to develop the framework of severe accident code, COMPASS (COre Meltdown Progression Accident Simulation Software), covering the severe accident progression in a vessel from a core heat-up to a vessel failure as a stand-alone fashion. In order to analyze the effect of surrounding structure, the melt progression has been compared between the central zone and the most outer zone under the condition of constant radial power peaking factor. Figure 2 and 3 shows the fuel element temperature and the clad mass at the central zone, respectively. Due to the axial power peaking factor, the axial node No.3 has the highest temperature, while the top and bottom nodes have the lowest temperature. When the clad temperature reaches to the Zr melting temperature (2129.15K), the Zr starts to melt. The axial node No.2 reaches to the fuel melting temperature about 5000 sec and the molten fuel relocates to the node No.1, which results to the blockage of flow area in node No.1. The blocked flow area becomes to open about 6100 sec due to the molten ZrO{sub 2} mass relocation to core support plate. Figure 4 and 5 shows the fuel element temperature and the clad mass at the most outer zone, respectively. It is shown that the fuel temperature increase more slowly

  12. Crown color match of implant-supported zirconia and Porcelain-Fused-to-Metal restorations:

    DEFF Research Database (Denmark)

    Peng, Min; Fei, Wei; Hosseini, Mandana;

    2014-01-01

    Objectives: The aim of the present study was to compare the crown color match of implant supported zirconia restorations and Porcelain-Fused-to-Metal (PFM) restorations in anterior maxillary region by spectrophotometric evaluation. Materials and Methods: Eighteen patients with 29 implant......-supported single crowns in anterior maxillary area were recruited, 11 of the implant crowns were zirconia restorations and 18 were PFM restorations. Color match of the implant crown with contra-lateral/neighboring tooth at the position of body 1/3 of the crown were assessed using spectrophotometer (Spectro......ShadeTM, Micro Dental) in CIEL¿a¿b¿ coordinates. Subjective crown color match scores were evaluated. Independent sample t test of SPSS17.0 was used to compare the difference between zirconia restoration and PFM restoration. Spearman correlation was used to analyze the relationship between the spectrophotometric...

  13. Can hyaluronan injections augment deficient papillae at implant-supported crowns in the anterior maxilla?

    DEFF Research Database (Denmark)

    Bertl, Kristina; Gotfredsen, Klaus; Jensen, Simon S;

    2016-01-01

    OBJECTIVES: The present randomized controlled trial aimed to assess the effect of hyaluronan (HY) injections to augment deficient interproximal papillae at implant-supported crowns in the anterior maxilla. METHODS: Twenty-two patients with a deficient papilla in the anterior maxilla next to an im......OBJECTIVES: The present randomized controlled trial aimed to assess the effect of hyaluronan (HY) injections to augment deficient interproximal papillae at implant-supported crowns in the anterior maxilla. METHODS: Twenty-two patients with a deficient papilla in the anterior maxilla next...... index score (MPIS), and standard clinical periodontal parameters. Pain level after injection was recorded on a visual analogue scale (VAS). The deficient area was evaluated on clinical photographs, and the esthetic appearance was recorded on a VAS. Differences in mucosal volume were assessed after 3...

  14. Evaluation of the landscape surrounding northern bobwhite nest sites: A multiscale analysis

    Science.gov (United States)

    White, C.G.; Schweitzer, Sara H.; Moore, C.T.; Parnell, I.B.; Lewis-Weis, L.A.

    2005-01-01

    Implementation of the Conservation Reserve Program (CRP) altered the interspersion and abundance of patches of different land-cover types in landscapes of the southeastern United States. Because northern bobwhites (Colinus virginianus) are experiencing significant population declines throughout most of their range, including the Southeast, it is critical to understand the impacts of landscape-scale changes in habitat on their reproductive rates. Our objective was to identify components of landscape structure important in predicting nest site selection by bobwhites at different spatial scales in the Upper Coastal Plain of Georgia. We used a Geographic Information System (GIS) and spatial analysis software to calculate metrics of landscape structure near bobwhite nest sites. Logistic regression was used to model the relationship of nest sites to structure within the surrounding landscape at 4 spatial scales. We found that patch density and open-canopy planted pine were consistently important predictor variables at multiple scales, and other variables were important at various scales. The density of different patch types could be increased by thinning rows of pines in large monotypic stands of closed-canopy planted pine stands. Thinning and creating openings in CRP pine plantations should provide increased nesting opportunities for bobwhites. We interpret the support for other variables in our analysis as an indication that various patch configuration lead to different combinations of landscape structure that provide an acceptable range of habitat conditions for bobwhites.

  15. Rehabilitation with implant-supported overdentures in total edentulous patients: A review

    OpenAIRE

    Martínez-Lage Azorín, L.; Segura Andrés, Gustavo; Faus López, Joan; Agustín Panadero, Rubén

    2013-01-01

    Objectives: The main aim of this review article is to discuss implant-supported overdentures (ISOs) as treatment in edentulous patients. Besides, we will try to discuss among the different treatment options in such patients and to analyze their validity when ISOs are compared with other clinical modalities. At the same time, we will try to suggest clinical guidelines supported by current clinical studies. Material and methods: We performed a Medline search and review of pertinent articles on ...

  16. Implant-supported hybrid prosthesis: Conventional treatment method for borderline cases.

    Science.gov (United States)

    Egilmez, Ferhan; Ergun, Gulfem; Cekic-Nagas, Isil; Bozkaya, Suleyman

    2015-01-01

    An implant-supported hybrid prosthesis is an acrylic resin complete fixed dental prosthesis and supported by implants might be a solution in extreme cases that the need of the restoration for esthetics, function, lip support, and speech. This clinical report aims to present the esthetic and functional prosthetic rehabilitation of three borderline cases with implant-supported hybrid prostheses. Patient 1 (62-year-old man) and Patient 2 (61-year-old man) presented a chief complaint of a compromised esthetic. After clinical evaluations, in Patient 1, 8 implants in the maxilla and 7 implants in mandibula were observed. Patient 2 had 7 implants in the maxilla and 7 implants in mandibula, which were previously placed. The intra-arch dimension of both patients was excessive and an insufficient peri-oral soft tissue support was observed. Patient 3 was a 61-year-old man had 2 implants with a history of previously implanted graft infection and implant loss on his maxillary posterior jaw. An excessive intra-arch dimension was observed in clinical examination. In addition, massive bone defect and insufficient soft tissue support were examined. In all patients, implant-supported hybrid prostheses were successfully performed. The clinical and radiologic findings were satisfactory. After 3 years of follow-up, no functional, phonetic, or esthetic problems with the restorations were noted. These case reports suggest that implant-supported hybrid prostheses can be a reliable alternative treatment procedure when a porcelain-fused metal fixed restoration does not satisfy a patient's requirements for esthetics, phonetics, oral hygiene, and oral comfort. PMID:26430378

  17. Implant Supported Mandibular Overdenture: A Viable Treatment Option for Edentulous Mandible

    OpenAIRE

    Lambade, Dipti; Lambade, Pravin; Gundawar, Sham

    2014-01-01

    The prosthetic management of the edentulous patient has long been a major challenge. Complete maxillary and mandibular dentures have been the traditional standard of care. However, most of the patients report problems adapting to their mandibular denture due to a lack of comfort, retention, stability and inability to masticate. Implant-supported overdentures have been a common treatment for edentulous patients for the past 20 years and predictably achieve good clinical results. Implant suppor...

  18. Performance of attachments used in implant-supported overdentures: review of trends in the literature

    OpenAIRE

    Lee, Damian J.

    2013-01-01

    The purpose of this review is to examine the performance of attachments used in implant-supported overdenture (IOD) in both clinical and in vitro settings and report the compiled findings, comparisons, and trends in the research literature. Articles published in PubMed on IOD attachment systems and performance were reviewed. Non-original articles were excluded. For each article included, the type of study, number of implants, number of attachment systems, and study outcome were recorded. Of t...

  19. Maxillary cement retained implant supported monolithic zirconia prosthesis in a full mouth rehabilitation: a clinical report

    OpenAIRE

    Sadid-Zadeh, Ramtin; Liu, Perng-Ru; Aponte-Wesson, Ruth; O'Neal, Sandra J

    2013-01-01

    This clinical report presents the reconstruction of a maxillary arch with a cement retained implant supported fixed prosthesis using a monolithic zirconia generated by CAD/CAM system on eight osseointegrated implants. The prosthesis was copy milled from an interim prosthesis minimizing occlusal adjustments on the definitive prosthesis at the time of delivery. Monolithic zirconia provides high esthetics and reduces the number of metal alloys used in the oral cavity.

  20. Clinical Assessment of “All in One” Framework for Partial Implant - Supported Prosthesis

    OpenAIRE

    Vinuela, A.; de Parga, J.Martinez Vazquez; Del Rio, Highsmith J.

    2002-01-01

    INTRODUCTION: Restoration by implant-supported prosthesis seems to be a current option in the treatment of partially edentulous patients. Its success depends on the passive fit of the framework. Searching for new manufacturing materials and techniques to solve these problems, dental companies, combining clinical and experimental research, offer different solutions, such as Nobel Biocare, the “all in one” system, which is a framework designed by CAD/CAM. AIM OF PRESENTATION: Clinical and ra...

  1. Implant-supported overdenture with prefabricated bar attachment system in mandibular edentulous patient

    Science.gov (United States)

    Ha, Seung-Ryong; Song, Seung-Il; Hong, Seong-Tae; Kim, Gy-Young

    2012-01-01

    Implant-supported overdenture is a reliable treatment option for the patients with edentulous mandible when they have difficulty in using complete dentures. Several options have been used for implant-supported overdenture attachments. Among these, bar attachment system has greater retention and better maintainability than others. SFI-Bar® is prefabricated and can be adjustable at chairside. Therefore, laboratory procedures such as soldering and welding are unnecessary, which leads to fewer errors and lower costs. A 67-year-old female patient presented, complaining of mobility of lower anterior teeth with old denture. She had been wearing complete denture in the maxilla and removable partial denture in the mandible with severe bone loss. After extracting the teeth, two implants were placed in front of mental foramen, and SFI-Bar® was connected. A tube bar was seated to two adapters through large ball joints and fixation screws, connecting each implant. The length of the tube bar was adjusted according to inter-implant distance. Then, a female part was attached to the bar beneath the new denture. This clinical report describes two-implant-supported overdenture using the SFI-Bar® system in a mandibular edentulous patient. PMID:23236580

  2. Analysis of nonlinear dynamic character in the surrounding rock system for deep buried underground engineering

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yu; PENG Hai-you

    2010-01-01

    Combining the field monitoring results of a deep-buried tunnel in Chongqing,the dynamic characteristics of the surrounding rock system under high in situ stress was analyzed by phase space reconstruction, calculating correlation dimension, Kolmogorov entropy and largest Lyapunov exponents. Both the Kolmogorov entropy and largest Lyapunov exponents show that the surrounding rock system is a chaotic one. Based on this, a local model was applied to predict surrounding rock displacement, and a nonlinear dynamic model was derived to forecast the interaction of the surrounding rock and support structure. The local method was found to have an extremely small total error. Also, the nonlinear dynamic model forecasting curves agree with the monitoring ones very well. It is proved that the nonlinear dynamic characteristic study is very important in analyzing rock stability and predicting the evolution of rock systems.

  3. Three-dimensional photoelastic analysis of edentulous alveolar bone supported with magnet retained mandibular implant-supported overdentures%磁性附着体下颌种植覆盖义齿牙槽骨的三维光弹应力分析

    Institute of Scientific and Technical Information of China (English)

    佘文珺; 马璐; 何嘉菁; 张富强

    2011-01-01

    Objective: To study stress distribution of edentulous alveolar bone supported with magnet retained mandibu-lar implant -supported overdentures. Method: Photoelastic models of epoxy were fabricated according to the standard mandibular edentulous model with two implants in the canine areas. The bio-functional complete dentures was made and connected with magnet attachments. Force was applied in conditions of centric , lateral and protrusive occlusion. After stress frozen, photoelastic model slices of different areas were made and stress fringes were observed. Result: In conditions of centric , lateral and protrusive occlusion, the maximum stress was observed on the alveolar bone around implants, more stress was observed on the molar areas. Less tress was observed on the incisive areas. In centric or protrusive occlusion. Stress was focused on the buccal alveolar bone of molar areas and the lingual alveolar bone of incisive areas. In lateral occlusion , stress was focused on the buccal alveolar ridge of work side and the lingual alveolar ridge of balance side. Conclusion: Stress of magnet retained mandibular implant-supported overdentures was distributed not only on the alveolar bone around the implants but also on the residual alveolar ridges, which can decrease the stress of alveolar bone around implant and increase the health of implant.%目的:研究磁性附着体下颌种植覆盖义齿在各种咬合状态时下颌牙槽骨的应力分布。方法:选取标准无牙颌模型,在双侧尖牙区植入种植体,连接磁性附着体,翻制下颌环氧树脂模型,制作生物功能性全口义齿,分别在正中、前伸、侧向咬合时加载应力,冻结切片,观测各牙位应力条纹。结果:磁性附着体下颌种植覆盖义齿在正中、侧向、前伸咬合应力加载时种植体周围牙槽骨应力值最大,余留牙槽嵴后牙区所受应力大于前牙区。正中(牙合)、前伸(牙合)磨牙区最大应力值出现于

  4. Full Mouth Oral Rehabilitation by Maxillary Implant Supported Hybrid Denture Employing a Fiber Reinforced Material Instead of Conventional PMMA

    Science.gov (United States)

    Qamheya, Ala Hassan A.; Yeniyol, Sinem; Arısan, Volkan

    2015-01-01

    Many people have life-long problems with their dentures, such as difficulties with speaking and eating, loose denture, and sore mouth syndrome. The evolution of dental implant supported prosthesis gives these patients normal healthy life for their functional and esthetic advantages. This case report presents the fabrication of maxillary implant supported hybrid prosthesis by using Nanofilled Composite (NFC) material in teeth construction to rehabilitate a complete denture wearer patient. PMID:26557392

  5. Full Mouth Oral Rehabilitation by Maxillary Implant Supported Hybrid Denture Employing a Fiber Reinforced Material Instead of Conventional PMMA

    Directory of Open Access Journals (Sweden)

    Ala Hassan A. Qamheya

    2015-01-01

    Full Text Available Many people have life-long problems with their dentures, such as difficulties with speaking and eating, loose denture, and sore mouth syndrome. The evolution of dental implant supported prosthesis gives these patients normal healthy life for their functional and esthetic advantages. This case report presents the fabrication of maxillary implant supported hybrid prosthesis by using Nanofilled Composite (NFC material in teeth construction to rehabilitate a complete denture wearer patient.

  6. Analysis on mechanism and key factors of surrounding rock instability in deeply inclined roadway affected by argillation and water seepage

    Institute of Scientific and Technical Information of China (English)

    Ma Rui; Li Guichen; Zhang Nong; Liu Cong; Wei Yinghao; Zhang Ming

    2015-01-01

    Based on the characteristics of surrounding rocks for deeply inclined roadway affected by argillation and water seepage, a structure model of layer crack plate was established to analyze the shear sliding insta-bility mechanism. Through solid mechanics analysis of anchored surrounding rock with defect from water seepage, combined with numerical analysis for instability mechanism under water seepage in deeply inclined roadway, key factors were proposed. Results show that with increasing height of layer crack plate, lateral buckling critical load value for high wall of the roadway decreases;there is a multi-stage distribution for tensile stress along the anchor bolt with defect under pulling state condition;groundwater seepage seriously affects the strength of surrounding rock of the roadway, to some extent the plastic zone of the high side rises up to 8 m. Finally some support strategies were proposed for the inclined roadway and successfully applied to Haoyuan coal mine in Tiela mining area, western China.

  7. Elasto-plastic analysis of the surrounding rock mass in circular tunnel based on the generalized nonlinear unified strength theory

    Institute of Scientific and Technical Information of China (English)

    Huang Xiujie; Zhang Jixun; Yang Ling; Yang Shikou; Wang Xingli

    2016-01-01

    The present paper aims to establish a versatile strength theory suitable for elasto-plastic analysis of underground tunnel surrounding rock. In order to analyze the effects of intermediate principal stress and the rock properties on its deformation and failure of rock mass, the generalized nonlinear unified strength theory and elasto-plastic mechanics are used to deduce analytic solution of the radius and stress of tunnel plastic zone and the periphery displacement of tunnel under uniform ground stress field. The results show that: intermediate principal stress coefficient b has significant effect on the plastic range, the magnitude of stress and surrounding rock pressure. Then, the results are compared with the unified strength criterion solution and Mohr–Coulomb criterion solution, and concluded that the generalized nonlinear unified strength criterion is more applicable to elasto-plastic analysis of underground tunnel surrounding rock.

  8. ANALYSIS ON INCREMENTAL COHESION OF SURROUNDING ROCK DUE TO PRESTRESSED CABLE ANCHOR

    Institute of Scientific and Technical Information of China (English)

    夏建中; 闫莫明; 滕年保; 李方政

    1998-01-01

    A new method for determining the incremental cohesion △Cm of surrounding rock due toprestressed cable anchor is presented, and the formulas for △Cm are deduced and ACredistributions also are discussed, based on the two anchorage effects, one is the effect with theprestressed value △Q3 of cable anchor improving the stress state of surrounding rock andincreasing the surrounding rock strength, the other is the fully encapsulated effect. Thedetermined incremental cohesion △Cm is subjected to the model test and field measurement in thereferences, and coincides well with those tested results. The formulas for △Cm can be used indesigning supoport parameters and related numerical analyses of prestressed cable anchor.

  9. Research on the stability analysis and design of soil tunnel surrounding rock

    Institute of Scientific and Technical Information of China (English)

    Zheng Yingren; Qiu Chenyu; Xiao Qiang

    2010-01-01

    The paper first analyzes the failure mechanism and mode of tunnel according to model experiments and mechanical calculation and then discusses the deficiency of taking the limit value of displacement around the tunnel and the size of the plastic zone of surrounding rock as the criterion of stability.So the writers put forward the idea that the safety factor of surrounding rock calculated through strength reduction FEM(finit element method)should be regarded as the criterion of stability,which has strict mechanical basis and unified standard and would not be influenced by other factors.The paper also studies the safety factors of tunnel surrounding rock(safety factors of shear and tension failure)and lining and some methods of designing and calculating tunnels.At last,the writers take the loess tunnel for instance and show the design and calculation results of two-lane railway tunnel.

  10. Integrated passenger terminal capacity analysis under the capacity constraints of surrounding road network

    Science.gov (United States)

    Zhou, Xuemei; Huang, Huang; Jia, Xinchang; Jiang, Nan

    2014-11-01

    Forecasting the demand of an integrated passenger terminal under the capacity constraints of its surrounding roads has always been a challenging problem for urban transportation terminals planning and construction in China. A bi-level model is proposed to forecast the passenger demand of an integrated terminal, whose throughput is restricted by the capacity of its surrounding road network. The upper level model maximizes the passenger flow of a terminal considering the capacity constraints of its surrounding road network. The User Equilibrium (UE) model is adopted as lower level model for traffic assignment. The adaptive genetic algorithm (AGA) is applied to solve this bi-level problem. The West-Lanzhou integrated passenger terminal in the Lanzhou city of China is used to test the feasibility and effectiveness of the proposed model. Test results show that, to reduce traffic congestion at the terminal, priority should be given to transportation mode with higher performance.

  11. Retention system for implant-supported dentures used by brazilian dentists who work in implant dentistry

    OpenAIRE

    Saturnino Aparecido Ramalho; Fábio Pontes Dantas

    2010-01-01

    Objective: To provide the dentists with support in the choice of the cement or screw type of retention for implant-supported dentures, according to the patient’s problem. Methods: An opinion questionnaire was applied to a sample of 468 participants, all dentists working in the field of Implant Dentistry, of whom 272 (58.1%) participated in the 4th International Congress of Osseointegration of APCD, held in São Paulo (SP) from 6 to 9 May 2004, 119 (25.4%) participated in the 2nd International ...

  12. Implant supported prosthesis in an edentulous boy with Hypohidrotic Ectodermal Dysplasia - "A happy boy"

    DEFF Research Database (Denmark)

    Gjørup, Hans; Nyhuus, Lone; Buhl, Jytte

    2009-01-01

    were made to enhance speech and social well-being. The lower denture was retained by 2 ball attachments. 2. At the age of 8 years the dentures were remade because of need for augmentation of vertical dimensions, better fit, and better aesthetics for an 8 year old with mixed dentition in the anterior......Implant supported prosthesis in an edentulous boy with Hypohidrotic Ectodermal Dysplasia - "A happy boy". Authors; Gjoerup,H1; Nyhuus,L2; Buhl,J3. 1) Center for Oral Health in Rare Conditions, Aarhus University Hospital 2) Prosthodontic Department, the Dental School, Aarhus University 3) Department...

  13. Full Mouth Rehabilitation of an Ectodermal Dysplasia Patient with Implant-Supported Prostheses: A Clinical Report

    Directory of Open Access Journals (Sweden)

    Rahab Ghoveizi

    2013-01-01

    Full Text Available Full mouth rehabilitation in patients with ectodermal dysplasia (ED is difficult to manage, especially because the afflicted individuals are quite young when they are evaluated for treatment; therefore, esthetics is an important concern. This clinical report describes the rehabilitation of a 19-year-old girl diagnosed with ectodermal dysplasia. Eleven implants were placed in the maxilla and mandible along with bone grafting to the upper jaw and both arches were constructed by metal-ceramic implant-supported fixed prostheses. This treatment plan seems to be favorable for ED patients.

  14. Numerical bifurcation analysis of distance-dependent on-center off-surround shunting neural networks.

    NARCIS (Netherlands)

    P.C.M. Molenaar; M.E.J. Raijmakers; H.L.J. van der Maas

    1996-01-01

    On-center off-surround shunting neural networks are often applied as models for content-addressable memory (CAM), the equilibria being the stored memories. One important demand of biological plausible CAMs is that they function under a broad range of parameters, since several parameters vary due to

  15. 上颌后牙骨量严重不足行上颌窦内提升术同期种植的临床效果分析%Clinical analysis of implant-supported rehabilitations with transalveolar technique and simultaneous implant placement in limited alveolar bone of posterior maxilla

    Institute of Scientific and Technical Information of China (English)

    岳喜龙; 周文娟; 柳忠豪

    2014-01-01

    目的:观察上颌后牙骨量严重不足即上颌窦底剩余牙槽骨高度( RBH)<5 mm行上颌窦内提升术同期植入种植体的临床效果。方法回顾性分析烟台市口腔医院种植中心2012年1月—2013年1月间收治的上颌后牙骨量严重不足( RBH<5 mm)行上颌窦内提升术同期种植的病例15例,共植入28颗瑞士Straumann种植体。术后8个月行上部结构修复,通过视觉评估法( visual analogue scale,VAS)分析患者术后反应及满意度,同时对种植体留存率,骨结合及边缘骨吸收情况进行观察。结果 VAS显示11例患者(73.3%)无明显疼痛及肿胀反应,无头痛、发热、鼻出血等症状,未影响日常生活;4例患者(27.7%)表现轻微疼痛。10例患者(66.7%)表示可接受此次治疗的费用,4例患者(26.7%)认为此次治疗费用偏高,1例患者(6.7%)表示不能接受此次治疗的费用。13例患者(86.7%)表示如需再次进行此种治疗愿意接受,2例患者(13.3%)表示拒绝,患者总体表现对此种治疗方式满意度较高。8个月后CBCT显示种植体周围可见新骨形成,达到良好骨结合状态,上部结构修复1年后,28颗种植体无一脱落,留存率为100%,影像学检查见种植体平均边缘骨吸收(1.2±0.5) mm。在本研究中,15例患者平均RBH为(3.5±1.2)mm,平均上颌窦提升高度为(6.3±1.2)mm。结论上颌后牙区骨量严重不足(RBH<5 mm)行上颌窦内提升技术同期植入种植体亦可取得较好的临床效果,但此类病例为高度复杂病例,术前需要完善的检查,术中需经验丰富的临床医生细致操作,术后应用抗生素预防感染。%Objective To observe the clinical effects of implant-supported rehabilitations with transalveolar technique and simultaneous implant placement on limited alveolar bone of posterior maxilla ( RBH<5

  16. Various Techniques to Increase Keratinized Tissue for Implant Supported Overdentures: Retrospective Case Series

    Directory of Open Access Journals (Sweden)

    Ahmed Elkhaweldi

    2015-01-01

    Full Text Available Purpose. The purpose of this retrospective case series is to describe and compare different surgical techniques that can be utilized to augment the keratinized soft tissue around implant-supported overdentures. Materials and Methods. The data set was extracted as deidentified information from the routine treatment of patients at the Ashman Department of Periodontology and Implant Dentistry at New York University College of Dentistry. Eight edentulous patients were selected to be included in this study. Patients were treated for lack of keratinized tissue prior to implant placement, during the second stage surgery, and after delivery of the final prosthesis. Results. All 8 patients in this study were wearing a complete maxillary and/or mandibular denture for at least a year before the time of the surgery. One of the following surgical techniques was utilized to increase the amount of keratinized tissue: apically positioned flap (APF, pedicle graft (PG, connective tissue graft (CTG, or free gingival graft (FGG. Conclusions. The amount of keratinized tissue should be taken into consideration when planning for implant-supported overdentures. The apical repositioning flap is an effective approach to increase the width of keratinized tissue prior to the implant placement.

  17. Scenario analysis of land use change in Horqin Desert and its surrounding area

    NARCIS (Netherlands)

    Zhang, Y.M.; Zhao, S.; Verburg, P.H.

    2004-01-01

    Horqin desert and its surrounding area(41°17'~45°24' N,116°21'~123°30' E),loca-ted in the eastern part of agro-pas ture transitional zone in northern China,is an area sensitive to environmental change due to transitional location and the high potential for sandy desert-if ication.During the past dec

  18. Metagenomic analysis of bacterial and archaeal assemblages in the soil-mousse surrounding a geothermal spring

    Directory of Open Access Journals (Sweden)

    Sonu Bhatia

    2015-09-01

    Full Text Available The soil-mousse surrounding a geothermal spring was analyzed for bacterial and archaeal diversity using 16S rRNA gene amplicon metagenomic sequencing which revealed the presence of 18 bacterial phyla distributed across 109 families and 219 genera. Firmicutes, Actinobacteria, and the Deinococcus-Thermus group were the predominant bacterial assemblages with Crenarchaeota and Thaumarchaeota as the main archaeal assemblages in this largely understudied geothermal habitat. Several metagenome sequences remained taxonomically unassigned suggesting the presence of a repertoire of hitherto undescribed microbes in this geothermal soil-mousse econiche.

  19. Maternal factors required for oocyte developmental competence in mice: transcriptome analysis of non-surrounded nucleolus (NSN) and surrounded nucleolus (SN) oocytes.

    Science.gov (United States)

    Ma, Jun-Yu; Li, Mo; Luo, Yi-Bo; Song, Shuhui; Tian, Dongmei; Yang, Jin; Zhang, Bing; Hou, Yi; Schatten, Heide; Liu, Zhonghua; Sun, Qing-Yuan

    2013-06-15

    During mouse antral follicle development, the oocyte chromatin gradually transforms from a less condensed state with no Hoechst-positive rim surrounding the nucleolus (NSN) to a fully condensed chromatin state with a Hoechst-positive rim surrounding the nucleolus (SN). Compared with SN oocytes, NSN oocytes display a higher gene transcription activity and a lower rate of meiosis resumption (G2/M transition), and they are mostly arrested at the two-cell stage after in vitro fertilization. To explore the differences between NSN and SN oocytes, and the maternal factors required for oocyte developmental competence, we compared the whole-transcriptome profiles between NSN and SN oocytes. First, we found that the NSN and SN oocytes were different in their metabolic pathways. In the phosphatidylinositol signaling pathway, the SN oocytes tend to produce diacylglycerol, whereas the NSN oocytes tend to produce phosphatidylinositol (3,4,5)-trisphosphate. For energy production, the SN oocytes and NSN oocytes differed in the gluconeogenesis and in the synthesis processes. Second, we also found that the key genes associated with oocyte meiosis and/or preimplantation embryo development were differently expressed in the NSN and SN oocytes. Our results illustrate that during the NSN-SN transition, the oocytes change their metabolic activities and accumulate maternal factors for further oocyte maturation and post-fertilization embryo development.

  20. Improved response surface method and its application in stability reliability degree analysis of tunnel surrounding rock

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    An approach of limit state equation for surrounding rock was put forward based on deformation criterion. A method of symmetrical sampling of basic random variables adopted by classical response surface method was mended, and peak value and deflection degree of basic random variables distribution curve were took into account in the mended sampling method. A calculation way of probability moment, based on mended Rosenbluth method, suitable for non-explicit performance function was put forward.The first, second, third and fourth order moments of functional function value were calculated by mended Rosenbluth method through the first, second, third and fourth order moments of basic random variable. A probability density the function(PDF) of functional function was deduced through its first, second, third and fourth moments, the PDF in the new method took the place of the method of quadratic polynomial to approximate real functional function and reliability probability was calculated through integral by the PDF for random variable of functional function value in the new method. The result shows that the improved response surface method can adapt to various statistic distribution types of basic random variables, its calculation process is legible and need not iterative circulation. In addition, a stability probability of surrounding rock for a tunnel was calculated by the improved method,whose workload is only 30% of classical method and its accuracy is comparative.

  1. Atrophy of muscles surrounding the shoulder in hemiplegia. Analysis with MRI

    International Nuclear Information System (INIS)

    Decrease of range of motion and subluxation of shoulders are common secondary dysfunctions after the stroke. The purpose of this study is to evaluate the atrophy of muscles surrounding shoulders in hemiplegic patients and to delineate the correlations between those atrophies and shoulder functions. MRI studies were done on bilateral shoulders in 13 hemiplegic patients with shoulder pain. The cross sectional areas of muscles surrounding shoulder, i.e., subscapularis, supraspinatus, infraspinatus, teres minor and deltoid muscle were measured on those images obtained. The degree of atrophies were evaluated by dividing cross-sectional area of the muscle on affected shoulder by that of non-affected shoulder, that is muscle atrophy ratio [MAR], for each muscle in every case. Also, the range of movements [ROM], the degree of subluxation and muscle strength of shoulder flexion were evaluated. All muscle cross-sectional areas on the affected side were significantly smaller than those of muscles on the unaffected side (p<0.01). The means of MARs were 0.68, 0.69, 0.86, 0.72 and 0.69 for subscapularis, supraspinatus, infraspinatus, teres minor and deltoid muscle. The pattern of muscle atrophies, however, varies from case to case. Both correlations of ROM versus supraspinatus MAR and degree of shoulder subluxation versus deltoid MAR were statistically significant (p<0.05). These results indicate the contribution of muscle atrophy to the shoulder dysfunction in hemiplegic patients. (author)

  2. Marginal tissue response adjacent to Astra Dental Implants supporting overdentures in the mandible

    DEFF Research Database (Denmark)

    Gotfredsen, K; Holm, B; Sewerin, I;

    1993-01-01

    The aim of this study was to evaluate the marginal tissue response adjacent to implant supported overdentures. Twenty edentulous patients had 2 Astra Dental Implants placed in the canine region of the lower jaw. New overdentures were retained by individual ball attachments in 11 patients...... that two osseointegrated Astra Dental Implants could successfully retain an overdenture in the lower jaw. However, long-term observation is needed for a definitive evaluation of this treatment concept....... showed any periodontal signs of failure. At the 2-year examination, no pocket depths adjacent to the implants exceeded 4 mm and no bone loss exceeded 3 mm. The mean annual bone loss was less than 0.2 mm during the first 2 years. The preliminary results from this limited study were promising and showed...

  3. Prosthetic management of an extensive maxillary alveolar defect with an implant-supported restoration.

    Science.gov (United States)

    Saadat, Fariborz; Mosharraf, Ramin

    2013-05-01

    Despite the recent developments in peri-implant surgical regenerative procedures, re-establishing the hard and soft tissue contour is still a challenge in cases with severe ridge deficiency. It becomes more difficult when incorrectly placed implants cause screw connections to come out onto the labial surfaces of the teeth. A two-part maxillary implant supported fixed restoration was constructed. The first part was consisted of a screw retained sub-structure that replaced gingival portions of the deficient maxilla and the second part was a cement retained super-structure that reconstructed the anatomical crowns of the lost teeth. In this way awkwardly placed implants did not interfere with the desired esthetic result. Another great advantage was that the alterations or repairs on cemented crowns can easily be carried out without compromising the entire construction. PMID:25512753

  4. Replacement of mandibular central incisors with implant-supported crowns: a case report.

    Science.gov (United States)

    Bäumer, Daniel; Zuhr, Otto; Hürzeler, Markus

    2016-01-01

    Anterior teeth are often affected by accidental dental trauma and may eventually be lost. When the neighboring teeth are unharmed, implant-supported crowns are often the preferred treatment choice. When not only the teeth but also the supporting hard and soft tissue has been lost, surgical reconstruction may be needed. However, in combined horizontal and vertical class III defects, the available augmentation techniques are often not predictable. In this case report, two neighboring mandibular central incisors were replaced by two implants after soft and hard tissue augmentation with the cortical bone plate method. The interdental soft tissue was reconstructed with remarkable success, making this an example of what can be achieved in cases such as this. PMID:27092347

  5. Retentiveness of implant-supported metal copings using different luting agents

    Directory of Open Access Journals (Sweden)

    Farahnaz Nejatidanesh

    2012-01-01

    Full Text Available Background: With regard to potential retrievability of cement-retained implant restorations, the retentive strength of the luting agents is critical. The aim of this study was to evaluate the retention values of implant-supported metal copings using different luting agents. Materials and Methods: Twenty ITI implant analogs and solid abutments of 5.5-mm height were embedded vertically in autopolymerizing acrylic resin blocks. Metal copings with a loop on the occlusal surface were fabricated using base metal alloy (Rexillium III. The copings were luted using eight cements with different retention mechanisms (Panavia F2.0, Fuji Plus, Fleck′s, Poly F, Fuji I, Temp Bond, GC-free eugenol, and TempSpan under static load of 5 kg (n=10. All specimens were incubated at 37°C for 24 hours, conditioned in artificial saliva for 7 days and thermocycled for 5000 cycles (5-55°C. The dislodging force was measured using a universal testing machine at a crosshead speed of 5 mm/min. Statistical analyses were performed using Kruskal-Wallis (α=0.05 and Mann-Whitney tests with Bonferroni correction (α=0.001. Results: Fuji Plus and TempSpan had the highest and the least mean retentive strength, respectively (320.97±161.47, 3.39±2.33. There was no significant difference between Fuji Plus, Fleck′s, Ploy F, and Panavia F2.0. These cements were superior to provisional cements and Fuji I (P<0.001 which showed statistically same retentive strength. Conclusion: Within the conditions of this study, the resin modified glass ionomer, zinc phosphate, zinc polycarboxylate, and Panavia F2.0 had statistically the same retentive quality and are recommended for definitive cementation of single implant-supported restorations. The provisional cements and glass ionomer may allow retrievability of these restorations.

  6. Theoretical analysis of a new segmented anchoring style in weakly cemented soft surrounding rock

    Institute of Scientific and Technical Information of China (English)

    Zhao Zenghui; Wang Weiming; Wang Lihua

    2016-01-01

    According to the tensile failure of rock bolt in weakly cemented soft rock, this paper presents a new seg-mented anchoring style in order to weaken the cumulative effect of anchoring force associated with the large deformation. Firstly, a segmented mechanical model was established in which free and anchoring section of rock bolt were respectively arranged in different deformation zones. Then, stress and displace-ment in elastic non-anchoring zone, elastic anchoring zone, elastic sticking zone, softening sticking zone and broken zone were derived respectively based on neural theory and tri-linear strain softening constitutive model of soft rock. Results show that the anchoring effect can be characterized by a supporting parameter β. With its increase, the peak value of tangential stress gradually moves to the roadway wall, and the radial stress significantly increases, which means the decrease of equivalent plastic zone and improvement of confining effect provided by anchorage body. When β increases to 0.72, the equivalent plastic zone disappears, and stresses tend to be the elastic solutions. In addition, the anchoring effect on the displacement of surrounding rock can be quantified by a normalization factorδ.

  7. Precipitation Depth-Duration-Frequency Analysis for the Nevada National Security Site and Surrounding Areas

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Li [Desert Research Inst. (DRI), Las Vegas, NV (United States). Division of Hydrologic Sciences; Miller, Julianne J. [Desert Research Inst. (DRI), Las Vegas, NV (United States). Division of Hydrologic Sciences

    2016-08-01

    Accurate precipitation frequency data are important for Environmental Management Soils Activities on the Nevada National Security Site (NNSS). These data are important for environmental assessments performed for regulatory closure of Soils Corrective Action Unit (CAU) Sites, as well as engineering mitigation designs and post-closure monitoring strategies to assess and minimize potential contaminant migration from Soils CAU Sites. Although the National Oceanic and Atmospheric Administration (NOAA) Atlas 14 (Bonnin et al., 2011) provides precipitation frequency data for the NNSS area, the NNSS-specific observed precipitation data were not consistent with the NOAA Atlas 14 predicted data. This is primarily due to the NOAA Atlas 14 products being produced from analyses without including the approximately 30 NNSS precipitation gage records, several of which approach or exceed 50 year of record. Therefore, a study of precipitation frequency that incorporated the NNSS precipitation gage records into the NOAA Atlas 14 dataset, was performed specifically for the NNSS to derive more accurate site-specific precipitation data products. Precipitation frequency information, such as the depth-duration-frequency (DDF) relationships, are required to generate synthetic standard design storm hydrographs and assess actual precipitation events. In this study, the actual long-term NNSS precipitation gage records, some of which are the longest gage records in southern and central Nevada, were analyzed to allow for more accurate precipitation DDF estimates to be developed for the NNSS. Gridded maps of precipitation frequency for the NNSS and surrounding areas were then produced.

  8. Analysis of land surface parameters and turbulence characteristics over the Tibetan Plateau and surrounding region

    Science.gov (United States)

    Wang, Yinjun; Xu, Xiangde; Liu, Huizhi; Li, Yueqing; Li, Yaohui; Hu, Zeyong; Gao, Xiaoqing; Ma, Yaoming; Sun, Jihua; Lenschow, Donald H.; Zhong, Shiyuan; Zhou, Mingyu; Bian, Xindi; Zhao, Ping

    2016-08-01

    Based on the results from 11 flux sites during the third Tibetan Plateau (TP) Experiment (TIPEX III), land surface parameters and the turbulence characteristics of the atmospheric surface layer over the TP and surrounding region are analyzed. Monin-Obukhov similarity theory has been used to calculate the aerodynamic roughness length z0m and the excess resistance to heat transfer kB- 1 = ln(z0m/z0h), and the factors that cause variations of z0m and kB- 1 are investigated. The main drivers for the diurnal variations of surface albedo (α) at different sites are solar elevation, solar radiation, and soil moisture. The eddy correlation method is utilized to inversely calculate bulk transfer coefficients for momentum (CD) and heat (CH) at different sites. The relationships between CD and CH and the wind speed at 10 m follow a power law for unstable stratification. For stable stratification, both CD and CH increase with increasing wind speed when wind speed is less than 5 m/s. Diurnal variations of turbulent fluxes are compared at different sites, and the relationships between turbulent fluxes and other variables are analyzed. Wind speed variance normalized by the friction velocity (σu/u*, σv/u*, σw/u*) for neutral stratification (Cu1, Cv1, Cw1), and temperature and humidity variance normalized by a temperature and humidity scale (σT/T*, σq/q*) under free convection (z/L < -0.1) (CT, Cq) are fitted with similarity relations. The differences in similarity constants (Cu1, Cv1, Cw1, CT, Cq) at different sites are discussed. For stable stratification, cases are divided into weakly stable conditions and intermittent turbulence, and the critical values for these two states are determined. Shear and buoyancy terms in the turbulence kinetic energy equation for different stratifications are analyzed.

  9. [Analysis on Regional Characteristics of Air Quality Index and Weather Situation in Beijing and Its Surrounding Cities During the APEC].

    Science.gov (United States)

    Gao, Qing-xian; Lu, Jun-rong; Wang, Ning; Li, Wen-tao; Gao, Wen-kang; Su, Bu-da

    2015-11-01

    Analysis on the revolution and regional characteristics of air quality by hourly monitored readings from 1 to 15 November 2014 released by Environmental Monitoring Station of China and research of the impacts of weather situation and meteorological elements released by China Meteorological Administration towards air quality of Beijing and its surrounding cities during the Asia-Pacific Economic Cooperation (APEC) indicated that: (1) The air quality was good because of the implementation of mitigation measures, while the Air Quality Index (AQI) increased along with the termination of mitigation measures. Thus it can be seen that mitigation measures made a great contribution to the improvement of air quality of Beijing and its surrounding cities. (2) Affected by thermal inversion layer, AQI of Beijing and its surrounding cities increased quickly during the initial of the implemental of reducing measures which proved that pollutants would accumulate in the context of unfavourable weather, hence the influence of weather situation towards air quality could not be ignored. (3) Although affected by thermal inversion layer, the concentration of pollutants of Beijing was not accumulated to a high degree at the end period of reducing measures, while Tianjin, Tangshan, Baoding and Xingtai suffered from moderate and severe pollution at the same time which further illustrated that the implementation of mitigation measures have made a great contribution to the improvement of air quality in Beijing during APEC.

  10. Trauma to an implant-supported crown that was saved by the fixation screw : a case report

    NARCIS (Netherlands)

    den Hartog, Laurens; Meijer, Henny J. A.; Stellingsma, Kees; Santing, Hendrik J.; Raghoebar, Gerry M.

    2010-01-01

    A traumatic impact to an implant-supported crown might damage the implant, restoration and peri-implant tissues. Ideally, only a small prosthetic retreatment is needed for restoration, as complicated prosthetic retreatments or surgical retreatments in particular, could be very inconvenient for the p

  11. Rehabilitation of the edentulous mandible with implant-supported overdenture using ball attachments and healing abutments: A case report

    OpenAIRE

    PARK, JUN-BEOM

    2009-01-01

    For many years, osseointegrated implant-supported overdentures have been used in the rehabilitation of the edentulous lower jaw with excellent results. In this report, additional implants with healing abutments were applied posterior to mental foramen on each side was used to achieve additional support to the overdenture.

  12. Fabricating a Soft Liner-Retained Implant-Supported Palatal Lift Prosthesis for an Edentulous Patient: A Case Report

    OpenAIRE

    Omid Savabi; Ebrahim Ataei; Niloufar Khodaeian

    2012-01-01

    This case report describes fabrication of a palatal lift prosthesis for a quadriplegic edentulous 30-year-old male with past head traumatic injury. We constructed an implant supported bar and used a soft-lining material for the maxillary palatal lift prosthesis to minimize the possibility of implant overloading and also provide a less complex and less expensive procedure for this patient.

  13. Mechanosensation and maximum bite force in edentulous patients rehabilitated with bimaxillary implant-supported fixed dental prostheses

    OpenAIRE

    Luraschi, Julien; Schimmel, Martin; Bernard, Jean-Pierre; Gallucci, German O; Belser, Urs Christophe; Muller, Frauke

    2012-01-01

    The aim of this study was to compare tactile sensitivity and maximum voluntary bite force (MBF) of edentulous patients with implant-supported fixed dental prostheses (IFDP/IFDPs) to those wearing complete dentures (CG-CC) and fully dentate subjects (CG-DD).

  14. A systematic review of implant-supported overdentures in the edentulous maxilla, compared to the mandible : How many implants?

    NARCIS (Netherlands)

    Raghoebar, Gerry M.; Meijer, Henny J. A.; Slot, Jan; Huddleston Slater, James J.R.; Vissink, Arjan

    2014-01-01

    Background and aim: There is now overwhelming evidence from systematic reviews that a two-implant overdenture is the first choice of treatment for the edentulous mandible. Conversely, consensus is lacking for implant-supported maxillary overdentures. Therefore, we systematically reviewed the treatme

  15. Morphological analysis of stylolites for paleostress estimation in limestones surrounding the Andra Underground Research Laboratory site

    CERN Document Server

    Rolland, Alexandra; Baud, Patrick; Conil, Nathalie; Landrein, Philippe

    2013-01-01

    We develop and test a methodology to infer paleostress from the morphology of stylolites within borehole cores. This non-destructive method is based on the analysis of the stylolite trace along the outer cylindrical surface of the cores. It relies on an automatic digitization of high-resolution photographs and on the spatial Fourier spectrum analysis of the stylolite traces. We test and show, on both synthetic and natural examples, that the information from this outer cylindrical surface is equivalent to the one obtained from the destructive planar sections traditionally used. The assessment of paleostress from the stylolite morphology analysis is made using a recent theoretical model, which links the morphological properties to the physical processes acting during stylolite evolution. This model shows that two scaling regimes are to be expected for the stylolite height power spectrum, separated by a cross-over length that depends on the magnitude of the paleostress during formation. We develop a non linear f...

  16. A structured analysis of uncertainty surrounding modeled impacts of groundwater-extraction rules

    Science.gov (United States)

    Guillaume, Joseph H. A.; Qureshi, M. Ejaz; Jakeman, Anthony J.

    2012-08-01

    Integrating economic and groundwater models for groundwater-management can help improve understanding of trade-offs involved between conflicting socioeconomic and biophysical objectives. However, there is significant uncertainty in most strategic decision-making situations, including in the models constructed to represent them. If not addressed, this uncertainty may be used to challenge the legitimacy of the models and decisions made using them. In this context, a preliminary uncertainty analysis was conducted of a dynamic coupled economic-groundwater model aimed at assessing groundwater extraction rules. The analysis demonstrates how a variety of uncertainties in such a model can be addressed. A number of methods are used including propagation of scenarios and bounds on parameters, multiple models, block bootstrap time-series sampling and robust linear regression for model calibration. These methods are described within the context of a theoretical uncertainty management framework, using a set of fundamental uncertainty management tasks and an uncertainty typology.

  17. Mechanical analysis on deformation of surrounding rock with road-in packing of gob-side entry retaining in fully-mechanized sub-level caving face

    Institute of Scientific and Technical Information of China (English)

    ZHU Chuan-qu; MIAO Xie-xing; LIU Ze

    2008-01-01

    Based on the movement regularity of surrounding rock with road-in packing of gob-side entry retaining in fully-mechanized sub-level caving face (RPGERFCF), the me-chanical model of its surrounding rock was established and the calculating formulas of the deformation of the roof, coal wall and filling body were attained. By the mechanical analy-sis to the deformation of the surrounding rock of RPGERFCF, the major factors influencing the deformation of the surrounding rock were found out and the technologic approaches reduced the deformation and enhanced the stability of the surrounding rock were put for-ward. Consequently, the scientific bases were provided for the stability control of the sur-rounding rock of RPGERFCF.

  18. Effect of Misfit on Preload Maintenance of Retention Screws of Implant-Supported Prostheses

    Science.gov (United States)

    Assunção, Wirley Gonçalves; Dos Santos, Paulo Henrique; Delben, Juliana Aparecida; Gomes, Érica Alves; Barão, Valentim Adelino Ricardo; Tabata, Lucas Fernando

    2009-10-01

    The aim of this study was to evaluate the effect of unilateral misfit at different levels on a crown-implant-retention screw system of implant-supported crowns. Hexagon castable UCLA abutments were cast in Co-Cr alloy to fabricate 48 metallic crowns divided into four groups ( n = 12). Group A: crowns did not present misfit; Groups B, C and D: crowns were fabricated with unilateral misfit of 50, 100, and 200 μm, respectively. The crowns were attached by titanium retention screw with 30 N/cm to external hexagonal osseointegrated implants embedded in acrylic resin. After 2 min, the retention screw of each replica was submitted to detorque evaluation by an analogic torque gauge. Three retention screws were used to perform detorque evaluation at each replica and the procedure was repeated twice with each screw. Each group was submitted to 72 detorque measurements. Data were evaluated by ANOVA and Tukey test ( P 0.05). Crowns with unilateral misfit presented higher preload decrease than crowns completely fitted to osseointegrated implants.

  19. Clinical Advantages and Limitations of Monolithic Zirconia Restorations Full Arch Implant Supported Reconstruction: Case Series

    Directory of Open Access Journals (Sweden)

    Joao Carames

    2015-01-01

    Full Text Available Purpose. The purpose of this retrospective case series is to evaluate the clinical advantages and limitations of monolithic zirconia restorations for full arch implant supported restorations and report the rate of complications up to 2 years after insertion. Materials and Methods. Fourteen patients received implant placement for monolithic zirconia full arch reconstructions. Four implants were placed in seven arches, eleven arches received six implants, two arches received seven implants, two arches received eight implants, and one arch received nine implants. Results. No implant failures or complications were reported for an implant survival rate of 100% with follow-up ranging from 3 to 24 months. Conclusions. Monolithic zirconia CAD-/CAM-milled framework restorations are a treatment option for full arch restorations over implants, showing a 96% success rate in the present study. Some of the benefits are accuracy, reduced veneering porcelain, and minimal occlusal adjustments. The outcome of the present study showed high success in function, aesthetics, phonetics, and high patient satisfaction.

  20. Retention system for implant-supported dentures used by brazilian dentists who work in implant dentistry

    Directory of Open Access Journals (Sweden)

    Saturnino Aparecido Ramalho

    2010-04-01

    Full Text Available Objective: To provide the dentists with support in the choice of the cement or screw type of retention for implant-supported dentures, according to the patient’s problem. Methods: An opinion questionnaire was applied to a sample of 468 participants, all dentists working in the field of Implant Dentistry, of whom 272 (58.1% participated in the 4th International Congress of Osseointegration of APCD, held in São Paulo (SP from 6 to 9 May 2004, 119 (25.4% participated in the 2nd International Congress of Implant Dentistry of Minas Gerais, between 10 and 12 June 2004 and 77 (16.5% were professors and specialization and master students from São Leopoldo Mandic. Results: The results showed that 254 participants opted for the screw-retained system while 214 opted for the cement-retained system. Conclusion: There was a preference for the use of the screw-retained system, and that both cemented and screw-retained systems have advantages and disadvantages, so that the dentist is left to decide and evaluate them in order to indicate and use them with confidence in different clinical cases.

  1. Effect of Vertical Misfit on Screw Joint Stability of Implant-Supported Crowns

    Science.gov (United States)

    Assunção, Wirley Gonçalves; Delben, Juliana Aparecida; Tabata, Lucas Fernando; Barão, Valentim Adelino Ricardo; Gomes, Érica Alves

    2011-08-01

    The passive fit between prosthesis and implant is a relevant factor for screw joint stability and treatment success. The aim of this study was to evaluate the influence of vertical misfit in abutment-implant interface on preload maintenance of retention screw of implant-supported crowns. The crowns were fabricated with different abutments and veneering materials and divided into 5 groups ( n = 12): Gold UCLA abutments cast in gold alloy veneered with ceramic (Group I) and resin (Group II), UCLA abutments cast in titanium veneered with ceramic (Group III) and resin (Group IV), and zirconia abutments with ceramic veneering (Group V). The crowns were attached to implants by gold retention screws with 35-N cm insertion torque. Specimens were submitted to mechanical cycling up to 106 cycles. Measurements of detorque and vertical misfit in abutment-implant interface were performed before and after mechanical cycling. ANOVA revealed statistically significant difference ( P titanium exhibited the highest misfit values. Pearson correlation test did not demonstrate significant correlation ( P > 0.05) between vertical misfit and detorque value. It was concluded that vertical misfit did not influence torque maintenance and the abutments cast in titanium exhibited the highest misfit values.

  2. Implant Supported Fixed Dental Prostheses Using a New Monotype Zirconia Implant—A Case Report

    Directory of Open Access Journals (Sweden)

    Stefan Roehling

    2015-09-01

    Full Text Available Currently, titanium or specific titanium alloys are the most often used materials for the fabrication of dental implants. Many studies have confirmed the osseointegrative capacity and clinical long-term performance of moderately rough titanium implants. However, disadvantages have also been reported with regard to peri-implant infections and the titanium metal properties. Tooth colored ceramic implants have attracted the interest of clinicians since the end of the 1960s. Initially, alumina was used for the fabrication of ceramic implants; however, due to the poor biomechanical properties, alumina implants are not commercially available any more. Since end of the 1990s, zirconia has been established in dentistry due to its superior biomechanical properties compared to other oxide ceramics such as alumina. Currently, zirconia is the material of choice for the fabrication of ceramic implants. Zirconia implants show superior biocompatibility compared to titanium and other metals. Additionally, it has been reported that zirconia implants with a micro-rough surface topography show at least a comparable osseointegrative capacity and similar clinical survival rates to moderately rough titanium implants. The present case reports a fixed implant-supported reconstruction of a large edentulous space with compromised local bone conditions using new monotype zirconia dental implants with a micro-rough surface topography.

  3. [Patient satisfaction with removable implant-supported prostheses in the edentulous mandible].

    Science.gov (United States)

    Zitzmann, Nicola U; Marinello, Carlo P

    2006-01-01

    The aim of the present study was to investigate patients' satisfaction with removable implant restorations with two or four implants compared to a complete denture (CD) in the edentulous mandible. 20 patients in each group were asked to fill out a questionnaire ("Patient satisfaction related to the prosthetic restoration") before treatment, after six months and three years. With implant restorations, either implant-retained (IRET) or implant-supported (ISUP), greater improvements in prostheses retention and pain reduction were achieved in comparison to complete dentures. In addition, restrictions related to food selection were resolved for most implant patients. Despite great inter-individual differences, there was a tendency for larger improvements of almost all parameters with IRET, except chewing ability, which was rated best with ISUP. Long-term results revealed that patients with ISUP (four implants) assessed prostheses retention with the highest ratings compared to those with IRET and CD (p = 0,0147). These results indicate that an improvement in functional and psychological parameters can be achieved with two implants, whilst stabilization with four implants improves prosthesis retention, chewing ability and pain reduction in the long term. Maintenance efforts were more complex for implant restorations than for CD and imply a recall at least once a year. PMID:16610459

  4. Performance of attachments used in implant-supported overdentures: review of trends in the literature.

    Science.gov (United States)

    Lee, Damian J

    2013-02-01

    The purpose of this review is to examine the performance of attachments used in implant-supported overdenture (IOD) in both clinical and in vitro settings and report the compiled findings, comparisons, and trends in the research literature. Articles published in PubMed on IOD attachment systems and performance were reviewed. Non-original articles were excluded. For each article included, the type of study, number of implants, number of attachment systems, and study outcome were recorded. Of the 283 articles found, 158 met the inclusion criteria. Ninety-four articles were clinical studies and 64 articles were in vitro studies. Studies on retention were the most common for in vitro studies, and four or more attachment systems were compared in most articles with significant differences in outcome. A clinical outcome of one attachment system was most common for clinical studies, while most studies had neutral outcomes overall. Ball attachment was the most commonly tested IOD attachment system. The trend in the literature showed that there is a large discrepancy between the study designs and outcomes between the clinical and the in vitro studies for IOD. Further clinical studies that can validate in vitro research should be encouraged to address this discrepancy between the two areas. PMID:23509021

  5. Dental Implant Supported Restorations Improve Quality of Life in Osteoporotic Women

    Directory of Open Access Journals (Sweden)

    Christine DeBaz

    2015-01-01

    Full Text Available Introduction. The aim of this study is to compare the quality of life (QoL in partially edentulous osteoporotic women who have missing teeth restored with dental implant retained restorations with those who do not and, secondarily, to report the rate of osteonecrosis in this sample. Methods. 237 participants completed the Utian QoL survey, a 23-question document measuring across psychosocial domains of well-being including occupational, health, emotional, and sexual domains which together contribute to an overall score. The subset of participants having dental implant supported prosthesis (64 was compared to the subset having nonimplant supported fixed restorations (47, the subset having nonimplant supported removable restorations (60, and the subset having no restoration of missing teeth (66. Results. ANOVA showed significant difference in all QoL domains between the four subsets (p<0.05. Although 134 reported oral bisphosphonate and 51 reported IV bisphosphonate use, no signs of ONJ were identified in any participants. Conclusion. These findings show implant retained oral rehabilitation has a statistically significant impact over nonimplant and traditional fixed restorations, removable restorations, and no restoration of missing teeth in far reaching areas including occupational, health, emotional, sexual, and overall QoL. These findings also support future examination of psychosocial outcomes associated with oral rehabilitation and the incorporation of oral health into women’s health promotion.

  6. A new classification of peri-implant bone morphology: a radiographic study of patients with lower implant-supported mandibular overdentures

    NARCIS (Netherlands)

    L. Zhang; W. Geraets; Y. Zhou; W. Wu; D. Wismeijer

    2014-01-01

    Objective This study aimed to classify peri-implant bone defects (PIBDs) on the basis of their radiographic appearance in a cohort of patients with lower implant-supported overdentures. Materials and methods Eighty-three patients with lower implant-supported overdentures were recruited to participat

  7. Numerical Analysis of Effect of Water on Explosive Wave Propagation in Tunnels and Surrounding Rock

    Institute of Scientific and Technical Information of China (English)

    XIA Chang-jing; SONG Zhen-duo; TIAN Lu-lu; LIU Hong-bin; WANG Lu; WU Xiao-fang

    2007-01-01

    Based on the application of practical engineering, propagation processes of explosive waves in rock with water well and tunnel are simulated by ANSYS/LS-DYNA software. The evolution of damage in rock is presented. The effect of water on the damage of the concrete slab in a tunnel is compared with damage inflicted without water. The numerical simulation illustrates that water plays an important role in the evolution of damage of the concrete slab in a mine tunnel. In the presence of water in the rock the concrete slab is damaged more severely than without water in rock. The effect of water location in the rock is also considered. It is found that the concrete slab in the tunnel shows various degrees of damage as a function of the different locations of water. Attenuation laws of stress waves over time-space in rock with water are also obtained. Numerical results indicate that, under blast loading, there are three zones in the rock: a crushed zone nearby the explosive charge, a damaged zone and an elastic zone. The conclusions of numerical analysis may provide references for blasting designs and structure protection.

  8. An analysis of water samples surrounding swine farms in Timis County – A practical guide

    Directory of Open Access Journals (Sweden)

    Valentin L. Ordodi

    2013-11-01

    Full Text Available The most important role in biological soil pollution is allocated to the untreated waste water used to ground’s fertirigation from livestock farms, and in particular of swine units. Applying of arbitrary measures, and national and European legislation’s non-compliance are main factors that often makes from this issue a public health problem by the great impact it can generate and create in large agglomerations and animals. The diluted manures are able to affect the quality of the environment mainly by: nitrous oxide, ammonia, methane, hydrogen sulphide, volatile organic compounds, etc. and they, being administered in soils, may cause epizootic and epidemiological aspects and also those relating to environmental protection. In this respect it rise the need for all livestock farms to apply appropriate measures for certain manure treatment, different to species of animals and depending on the collection and discharge systems used. This paper is an original research work and it intends to be also a practical guide to follow for those interested in field research of environmental pollution. There are presented current investigation methodologies of water’s quality from swine farms vicinity in Timis County. In four chapters are presented: primary water analysis methodology, the determination of chlorides, nitrates and phosphates for each substance being presented methodology, kits and reagents necessary specific results and their interpretation and conclusions for each study. The last chapter was allocated to the description of the potentially polluting compounds determination by GC-MS technique.

  9. Retentiveness of various luting agents used with implant-supported prosthesis: an in vitro study.

    Science.gov (United States)

    Garg, Pooja; Pujari, Malesh; Prithviraj, D R; Khare, Sumit

    2014-12-01

    Desired retrievability of cemented implant-supported fixed prosthesis makes the retentive strength of cementing agents an important consideration. The aim of the study was to evaluate the retentiveness of purposely designed implant cement and compare its retentiveness with dental cements that are commonly used with implant systems. Ten implant analogs were embedded in auto-polymerizing acrylic resin blocks and titanium abutments were attached to them. Fifty standardized copings were waxed directly on the abutment and casted. The cements used were: (1) resin-bonded zinc oxide eugenol cement, (2) purposely designed implant cement, (3) zinc phosphate cement, (4) zinc polycarboxylate cement, and (5) glass ionomer cement. After cementation, each sample was subjected to a pull-out test using universal testing machine and loads required to remove the crowns were recorded. The mean values and standard deviations of cement failure loads were analyzed using ANOVA and Bonferroni test. The mean values (± SD) of loads at failure (n = 10) for various cements were as follows (N): resin-bonded zinc oxide eugenol cement 394.62 (± 9.76), Premier implant cement 333.86 (± 18.91), zinc phosphate cement 629.30 (± 20.65), zinc polycarboxylate cement 810.08 (± 11.52), and glass ionomer cement 750.17 (± 13.78). The results do not suggest that one cement type is better than another, but they do provide a ranking order of the cements regarding their ability to retain the prosthesis and facilitate easy retrievability. PMID:25506659

  10. RETENTIVENESS OF VARIOUS LUTING AGENTS USED WITH IMPLANT SUPPORTED- PROSTHESIS: AN INVITRO STUDY.

    Science.gov (United States)

    Garg, Pooja; Pujari, Malesh L; D R, Prithviraj; Khare, Sumit

    2014-03-01

    Abstract ABSTRACT:Purpose: Desired retrievability of cemented implant-supported fixed prosthesis makes the retentive strength of cementing agents an important consideration. The aim of the study was to evaluate the retentiveness of purposely-designed implant cement and to compare its retentiveness with dental cements that are commonly used with implant systems.Materials and method: Ten implant analogs were embedded in auto-polymerizing acrylic resin blocks and titanium abutments were attached to them. 50 standardized copings were waxed directly on the abutment and casted. The cements used were: 1. resin-bonded zinc oxide eugenol cement (Kalzinol, DPI), 2. purposely-designed implant cement (Premier implant cement), 3. zinc phosphate cement (DeTrey Zinc, Dentsply), 4. zinc polycarboxylate cement (Poly-F, Dentsply) and 5. glass ionomer cement (GC Gold Label, GC corporation, Japan). After cementation, each sample was subjected to a pull-out test using universal testing machine and loads required to remove the crowns were recorded. The mean values and standard deviations of cement failure loads were analyzed using ANOVA and Bonferroni test.Results: The mean values (±SD) of loads at failure (n = 10) for various cements were as follows (N): resin-bonded zinc oxide eugenol cement 394.62 (±9.76), Premier implant cement 333.86 (±18.91), zinc phosphate cement 629.30 (±20.65), zinc polycarboxylate cement 810.08 (±11.52) and glass ionomer cement 750.17 (±13.78).Conclusions: The results do not suggest that one cement type is better than another, but they do provide a ranking order of the cements in their ability to retain the prosthesis and to facilitate its easy retrievability. PMID:24588463

  11. Orthodontic Microimplants Assisted Intrusion of Supra-erupted Maxillary Molar Enabling Osseointegrated Implant Supported Mandibular Prosthesis: Case Reports.

    Science.gov (United States)

    Rai, Deepak; Bhasin, Saranjeet Singh; Rai, Sheetal

    2014-12-01

    Loss of mandibular molars, when not replaced in time, are usually associated with overeruption of maxillary molars. To provide prosthetic replacement for missing lower posteriors, over erupted maxillary teeth have been intruded in past with great difficulty in adults with conventional orthodontics, along with associated problems of root resorption. Currently orthodontic microimplants provide stable intraoral anchorage, allow predictable maxillary molar intrusion enabling reestablishment of functional posterior occlusion with mandibular implant supported prosthesis, thereby reducing need for prosthetic crown reduction in maxillary arch. The added advantage of microimplant is it enables use of sectional appliance in area of concern instead of full arch bracketed appliance which an adult may not accept. The case reports demonstrates, overerupted maxillary molars were intruded using orthodontic microimplants to enable prosthetic rehabilitation of mandibular dentition by osseointegrated implant supported prosthesis. The second case report also demonstrates use of CBCT scan in planning and execution.

  12. Fabricating a Soft Liner-Retained Implant-Supported Palatal Lift Prosthesis for an Edentulous Patient: A Case Report

    Directory of Open Access Journals (Sweden)

    Omid Savabi

    2012-01-01

    Full Text Available This case report describes fabrication of a palatal lift prosthesis for a quadriplegic edentulous 30-year-old male with past head traumatic injury. We constructed an implant supported bar and used a soft-lining material for the maxillary palatal lift prosthesis to minimize the possibility of implant overloading and also provide a less complex and less expensive procedure for this patient.

  13. Comparing the Accuracy of Silicone and Polyether in Reproducing Gingival Height for Implant Supported Crown: an in vitro study

    OpenAIRE

    Derafshi R; Sabouri AA; Kazemeini J

    2015-01-01

    Statement of Problem: Accurate impressions are one of the most critical factors in achieving acceptable restorations. When pouring the impressions of implant supported restorations, soft materials like silicone and polyether are used to reconstruct the gingival form around the implants. To the best of our knowledge, no study has been conducted on the comparison of the accuracy of these soft materials. Objectives: To evaluate the accuracy of polyether and silicone in reproduc...

  14. Effect of pontic framework design on the fracture resistance of implant-supported all-ceramic fixed partial dentures

    OpenAIRE

    Ozgur Inan; Asli Secilmis; Oguz Eraslan

    2009-01-01

    Objective: The purpose of this study was to compare the fracture resistance of implant-supported all-ceramic fixed partial dentures, which have three different pontic designs. Material and Methods: Two implants were placed in a metal model simulating mandibular left second premolar and mandibular left second molar. Thirty standardized 3-unit all-ceramic fixed partial dentures with biconvex, convex or concave pontic designs were fabricated using IPS e.max system (n=10). Afterwards, specimens w...

  15. Implant-supported fixed restoration of post-traumatic mandibular defect accompanied with skin grafting: A clinical report

    OpenAIRE

    NOH, KWANTAE; Choi, Woo-Jin; Pae, Ahran

    2013-01-01

    Traumatic defects are mostly accompanied by hard and soft tissue loss. This report describes the surgical and prosthetic treatment of a patient with post-traumatic mandibular defect. A split-thickness skin graft was performed prior to implant placement and prefabricated acrylic stent was placed to hold the graft in place. The esthetic and functional demands of the patient were fulfilled by implant-supported screw-retained fixed prosthesis using CAD-CAM technology.

  16. The behavior of implant-supported dentures and abutments using the cemented cylinder technique with different resinous cements

    Directory of Open Access Journals (Sweden)

    Ivete Aparecida de Mathias Sartori

    2008-01-01

    Full Text Available Objective: Evaluate the behavior of implant-supported dentures and their components, made by cemented cylinder technique, using threetypes of resin cements. Methods: Fifty three patients, of whom 26 were women and 27 men, aged between 25 and 82 years. Results: With partial (54.43% and total (45.57% implant-supported dentures, of the Cone Morse, external and internal hexagon types (Neodent®, Curitiba, Brazil, totaling 237 fixations, were analyzed. The resin cements used were Panavia® (21.94%, EnForce® (58.23% and Rely X® (19.83% and the components were used in accordance with the Laboratory Immediate Loading - Neodent® sequence. The period of time of denture use ranged between 1 and 5 years. The results reported that 5(2.1% cylinders were loosened from metal structure (both belonging to Rely X group, 2(0.48% implants were lost after the first year of use, 16(6.75% denture retention screws wereloosened and 31(13.08% abutment screws were unloosened.Conclusion: The reasons for these failures probably are: metal structure internal retention failure, occlusal pattern, cementation technique and loading conditions. The cemented cylinder technique was effective when used in partial and total implant-supported rehabilitations, keeping prosthetic components stable, despite the resin cement utilized. However, further clinical studies must be conducted.

  17. Correlation Analysis of Gridding of Earthquakes in Datong and Its Surrounding Areas and Implication for Earthquake Prediction~

    Institute of Scientific and Technical Information of China (English)

    Sha Haijun; Liu Dongying

    2012-01-01

    On the basis of the earthquake (gL I〉3.0) catalog in North China from 1970 to 2009, the pattern of temporal and spatial distribution of medium-small earthquakes in Datong and its surrounding areas is studied by correlation analysis with a focus on its anomaly before moderate and strong earthquakes. With different spatial scales, temporal scales and time steps, the spatial distribution of earthquakes is converted to a sequence, then the correlation coefficients between the spatial distribution of medium-small earthquakes in a long-term and a longer time are calculated for the analysis of anomalies before moderate and strong earthquakes. In the study region center on the epicenter of the 1989 Datong- Yanggao earthquake (Ms5. 9) within a radius of less than 0.8~, with the time length of 3600 days, the longer time length of 3700 days, and the time step of 100 days, the correlation coefficient from 1980 to 2009 is steady between 0.94 and 1.00, but there were anomalies with values less than 0. 94 in the 2 years before the 1989 Datong-Yanggao earthquake (Ms 5.9), the 1991 Datong earthquake ( Ms 5.8) and 1999 Hunyuan earthquake (Ms 5. 6 ), which indicates the spatial distribution of a medium-small earthquake is very different from steady background seismicity. The implication for earthquake prediction from the anomaly of the correlation coefficient is also discussed with the three conclusions: (1) Before moderate and strong earthquakes in Datong and its surrounding areas, the obvious change of spatial distribution patterns of medium-small earthquake can be a kind of seismic precursor of the 2-year time scale for the prediction of an earthquake's time. (2) As the study region is restricted within a radius of less than 0. 8~, the result of correlation analysis is also good for the prediction of an earthquake's location. (3) The method of correlation analysis in this paper helps recognize the anomaly of spatial distribution of medium-small earthquake.

  18. Analysis of current density and specific absorption rate in biological tissue surrounding transcutaneous transformer for an artificial heart.

    Science.gov (United States)

    Shiba, Kenji; Nukaya, Masayuki; Tsuji, Toshio; Koshiji, Kohji

    2008-01-01

    This paper reports on the current density and specific absorption rate (SAR) analysis of biological tissue surrounding an air-core transcutaneous transformer for an artificial heart. The electromagnetic field in the biological tissue is analyzed by the transmission line modeling method, and the current density and SAR as a function of frequency, output voltage, output power, and coil dimension are calculated. The biological tissue of the model has three layers including the skin, fat, and muscle. The results of simulation analysis show SARs to be very small at any given transmission conditions, about 2-14 mW/kg, compared to the basic restrictions of the International Commission on nonionizing radiation protection (ICNIRP; 2 W/kg), while the current density divided by the ICNIRP's basic restrictions gets smaller as the frequency rises and the output voltage falls. It is possible to transfer energy below the ICNIRP's basic restrictions when the frequency is over 250 kHz and the output voltage is under 24 V. Also, the parts of the biological tissue that maximized the current density differ by frequencies; in the low frequency is muscle and in the high frequency is skin. The boundary is in the vicinity of the frequency 600-1000 kHz. PMID:18232363

  19. Field-mapping and petrographic analysis of volcanoes surrounding the Lake Natron Homo sapiens footprint site, northern Tanzania

    Science.gov (United States)

    Hewitt, S. M.; Zimmer, B.; Liutkus, C.; Carmichael, S. K.; McGinnis, K.

    2010-12-01

    The Lake Natron Homo sapiens footprint site is located in northern Tanzania along the East African Rift escarpment. The site is positioned south of Lake Natron within an ephemeral channel of the Engare Sero River. The hominid footprints are preserved in a tuff, which originated from one of the volcanic centers surrounding the site. Two large volcanoes in the surrounding region, including the active carbonatite producing Oldoinyo L’engai and the now extinct Kerimasi are possible sources. This area also contains over 30 smaller tuff cones and tuff rings that have been poorly mapped and not analyzed in detail. The site is significant as it is the oldest modern human trackway in East Africa and one of the largest collections of hominid footprints in the world. Determining the source of the footprinted volcanic ash requires detailed field mapping, and both petrographic and geochemical analyses. Extensive field-mapping of the region revealed multiple regional beds that stratigraphically overlay the footprinted layer. Age dating as well as geochemical analysis is being conducted to relate these beds to the footprinted layer. Field-mapping showed that the footprinted tuff is over 35 cm thick, suggesting a large, sustained eruption. The bulk of the tuff cones examined in the field visibly varied in composition to the footprinted tuff and, based on proximity to the footprint site, are too small to produce the requisite volume of ash. Field analysis of samples collected from Oldoinyo L’engai reveal the most similar mineral assemblages to the footprinted layer, and the large volcano provides a source substantial enough to create a thick ash bed 10 km north of the summit. Preliminary research reveals that the footprinted tuff is a phonolite, characterized by silica depletion and the presence of sanidine, augite, and annite with interstitial calcite. XRD analysis of samples collected from Oldoinyo L’engai reveal a nepheline-rich phonolite with zeolites (ie. phillipsite

  20. Intelligent direct analysis of physical and mechanical parameters of tunnel surrounding rock based on adaptive immunity algorithm and BP neural network

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Because of complexity and non-predictability of the tunnel surrounding rock, the problem with the determination of the physical and mechanical parameters of the surrounding rock has become a main obstacle to theoretical research and numerical analysis in tunnel engineering. During design, it is a frequent practice, therefore, to give recommended values by analog based on experience. It is a key point in current research to make use of the displacement back analytic method to comparatively accurately determi...

  1. Large-scale automated image analysis for computational profiling of brain tissue surrounding implanted neuroprosthetic devices using Python.

    Science.gov (United States)

    Rey-Villamizar, Nicolas; Somasundar, Vinay; Megjhani, Murad; Xu, Yan; Lu, Yanbin; Padmanabhan, Raghav; Trett, Kristen; Shain, William; Roysam, Badri

    2014-01-01

    In this article, we describe the use of Python for large-scale automated server-based bio-image analysis in FARSIGHT, a free and open-source toolkit of image analysis methods for quantitative studies of complex and dynamic tissue microenvironments imaged by modern optical microscopes, including confocal, multi-spectral, multi-photon, and time-lapse systems. The core FARSIGHT modules for image segmentation, feature extraction, tracking, and machine learning are written in C++, leveraging widely used libraries including ITK, VTK, Boost, and Qt. For solving complex image analysis tasks, these modules must be combined into scripts using Python. As a concrete example, we consider the problem of analyzing 3-D multi-spectral images of brain tissue surrounding implanted neuroprosthetic devices, acquired using high-throughput multi-spectral spinning disk step-and-repeat confocal microscopy. The resulting images typically contain 5 fluorescent channels. Each channel consists of 6000 × 10,000 × 500 voxels with 16 bits/voxel, implying image sizes exceeding 250 GB. These images must be mosaicked, pre-processed to overcome imaging artifacts, and segmented to enable cellular-scale feature extraction. The features are used to identify cell types, and perform large-scale analysis for identifying spatial distributions of specific cell types relative to the device. Python was used to build a server-based script (Dell 910 PowerEdge servers with 4 sockets/server with 10 cores each, 2 threads per core and 1TB of RAM running on Red Hat Enterprise Linux linked to a RAID 5 SAN) capable of routinely handling image datasets at this scale and performing all these processing steps in a collaborative multi-user multi-platform environment. Our Python script enables efficient data storage and movement between computers and storage servers, logs all the processing steps, and performs full multi-threaded execution of all codes, including open and closed-source third party libraries. PMID:24808857

  2. Analysis of the Radiopollution of the City of Sarajevo and its Surrounding Area with Regard to Radionuclides

    Directory of Open Access Journals (Sweden)

    Huremović, J.

    2009-04-01

    Full Text Available In recent years, great attention has been focused on the research of problems related to the environment and processes occurring within it. The accident that occurred at Nuclear Power Plant in Chernobyl (1986 unquestionably warned that global pollution with radioactive substances on a continent scale may be expected. The past twenty years have been marked with the utilization of metal uranium – a depleted isotope of uranium-235 for various purposes. Today, depleted uranium has found its use in modern armies and it is used as efficient ammunition against armored military systems.There are estimates about the usage of ammunition with depleted uranium deployed in Bosnia and Herzegovina during the war (1992–1995. The region of Bosnia and Herzegovina was exposed to the direct influence of the global dispersion processes that had occurred in May 1986 as a consequence of emissions originating from Nuclear Power Plant “Lenin” in Chernobyl. In thiswork the radionuclides fraction analysis (238U, 226Ra, 210Pb, 232Th, 40K i 137Cs of surface samples (0–5 cm originating from the City of Sarajevo and its surroundings has been presented. The soil samples were taken from nine locations in the city and the surrounding area: Blekin potok, Kobilja glava, Bentbaša, Vraca, Prirodno-matematieki fakultet (PMF, Aziai, Hrasnica, Butmir, and Blažuj. The analyses were performed at the Department for Environment of Jo?ef Štefan Institute in Ljubljana, Slovenia. Ge HP detector connected to Ortec MCA Gamma Vision 32 Software was used in addition to the Instrumental Neutron Activation Technique (INAA.The results of the analysis were compared with data available for the City of Sarajevo (years 1986, 1987 and 1988 and Slovenia. Analyses were made after Chernobyl catastrophe. Almost all of radionuclides analysed have shown to have a slightly higher specific radioactivity when compared to the data obtained in 1986, 1987 and 1989 for the City of Sarajevo. Our results

  3. CLASH: Complete Lensing Analysis of the Largest Cosmic Lens MACS J0717.5+3745 and Surrounding Structures

    CERN Document Server

    Medezinski, Elinor; Nonino, Mario; Merten, Julian; Zitrin, Adi; Broadhurst, Tom; Donahue, Megan; Sayers, Jack; Waizmann, Jean-Claude; Koekemoer, Anton; Coe, Dan; Molino, Alberto; Melchior, Peter; Mroczkowski, Tony; Czakon, Nicole; Postman, Marc; Meneghetti, Massimo; Lemze, Doron; Ford, Holland; Grillo, Claudio; Kelson, Daniel; Bradley, Larry; Moustakas, John; Bartelmann, Matthias; Benítez, Narciso; Biviano, Andrea; Bouwens, Rychard; Golwala, Sunil; Graves, Genevieve; Infante, Leopoldo; Jiménez-Teja, Yolanda; Jouvel, Stephanie; Lahav, Ofer; Moustakas, Leonidas; Ogaz, Sara; Rosati, Piero; Seitz, Stella; Zheng, Wei

    2013-01-01

    The galaxy cluster MACS J0717.5+3745 (z=0.55) is the largest known cosmic lens, with complex internal structures seen in deep X-ray, Sunyaev-Zel'dovich effect and dynamical observations. We perform a combined weak and strong lensing analysis with wide-field BVRi'z' Subaru/Suprime-Cam observations and 16-band Hubble Space Telescope observations taken as part of the Cluster Lensing And Supernova survey with Hubble (CLASH). We find consistent weak distortion and magnification measurements of background galaxies, and combine these signals to construct an optimally estimated radial mass profile of the cluster and its surrounding large-scale structure out to 5 Mpc/h. We find consistency between strong-lensing and weak-lensing in the region where these independent data overlap, 0.5, in terms of extreme value statistics we conclude that the mass of MACS J0717.5+3745 by itself is not in serious tension with LambdaCDM, representing only a ~2{\\sigma} departure above the maximum simulated halo mass at this redshift.

  4. A finite element study on stress distribution of two different attachment designs under implant supported overdenture

    Directory of Open Access Journals (Sweden)

    Mohamed I. El-Anwar

    2015-10-01

    Conclusions: Locator and ball and socket attachments induce equivalent stresses on bone surrounding implants. Locator attachment performance was superior to that of the ball and socket attachment in the implants, nylon caps, and overdenture. Locator attachments are highly recommended and can increase the interval between successive maintenance sessions.

  5. Masseter muscle thickness, chewing efficiency and bite force in edentulous patients with fixed and removable implant-supported prostheses: a cross-sectional multicenter study

    OpenAIRE

    Muller, Frauke; Hernandez, Marta; Gruetter Faineteau, Linda; Aracil-Kessler, Luis; Weingart, Dieter; Schimmel, Martin

    2012-01-01

    Edentulous patients may be restored with conventional dentures (C/C), implant-supported overdentures (IOD) or implant-supported fixed dental prostheses (IFDP). Null-hypotheses: chewing efficiency, maximum voluntary bite force (MBF) and masseter muscle thickness (MMT) are lower in patients with C/IOD compared with the patients with bimaxillary IFDPs. Both groups perform better than C/C and are inferior to fully dentate controls.

  6. Effect of cantilever length and alloy framework on the stress distribution in peri-implant area of cantilevered implant-supported fixed partial dentures

    OpenAIRE

    SUEDAM, Valdey; MORETTI NETO, Rafael Tobias; Edson Antonio Capello SOUSA; RUBO, José Henrique

    2016-01-01

    ABSTRACT Because many mechanical variables are present in the oral cavity, the proper load transfer between the prosthesis and the bone is important for treatment planning and for the longevity of the implant-supported fixed partial denture. Objectives To verify the stress generated on the peri-implant area of cantilevered implant-supported fixed partial dentures and the potential effects of such variable. Material and Methods A U-shaped polyurethane model simulating the mandibular bone c...

  7. Simplified Fabrication of an Esthetic Implant-Supported Crown With a Novel CAD/CAM Glass Ceramic.

    Science.gov (United States)

    Conejo, Julián; Blatz, Markus B

    2016-06-01

    Implant therapy and CAD/CAM technologies are advancing quickly, providing predictable esthetic and functional treatment options. A recent development involves the use of zirconia-reinforced lithium-silicate ceramic for fabrication of implant-supported restorations. Suitable for monolithic crowns, the material provides the optical advantages of a silicate ceramic with improved physical strength. Several prerequisites, however, are necessary to fabricate screw-retained monolithic restorations in the anterior maxilla. This case report demonstrates the clinical steps to fabricate a monolithic ceramic CAD/CAM crown on an immediately placed dental implant in the esthetic zone. PMID:27517477

  8. Functional aspects of treatment with implant-supported single crowns: a quality control study in subjects with tooth agenesis

    DEFF Research Database (Denmark)

    Goshima, Kenichi; Lexner, Michala O; Thomsen, Carsten Eckhart;

    2010-01-01

    after implant placement shortly before crown cementation, and again 1 month after cementation. It consisted of questionnaires [including Oral Health Impact Profile (OHIP-49)] and functional examination with plastic strips, the Dental Prescale Film and the Occluzer system, Xylitol color-changeable gum......BACKGROUND: No comprehensive patient-centered and clinical evaluations of the functional effect of treatment with implant-supported single crowns (ISSC) have been reported previously. OBJECTIVE: To investigate whether and how treatment with ISSC affects masticatory function and Oral Health...

  9. Immediate loading of maxillary and mandibular implant-supported fixed complete dentures: a 1- to 10-year retrospective study.

    Science.gov (United States)

    Ji, Ting-Jen; Kan, Joseph Y K; Rungcharassaeng, Kitichai; Roe, Phillip; Lozada, Jaime L

    2012-09-01

    This study evaluated the success rates of 50 full-arch maxillary and/or mandibular implant-supported fixed complete dentures. After a mean follow-up time of 42.1 months, 269 implants remained in function, which corresponded to cumulative implant success rates of 85.2% and an absolute success rate of 90.6% (269/297 implants). This study suggested that higher implant failure rates might be associated with a dental history of bruxism (29.3%) vs no history of bruxism (4.6%) and surgeons with limited experience (≤5 years; 12.2%) vs surgeons with experience (2.4%). PMID:21942324

  10. CLASH: COMPLETE LENSING ANALYSIS OF THE LARGEST COSMIC LENS MACS J0717.5+3745 AND SURROUNDING STRUCTURES

    International Nuclear Information System (INIS)

    The galaxy cluster MACS J0717.5+3745 (z = 0.55) is the largest known cosmic lens, with complex internal structures seen in deep X-ray, Sunyaev-Zel'dovich effect, and dynamical observations. We perform a combined weak- and strong-lensing analysis with wide-field BVRc i'z' Subaru/Suprime-Cam observations and 16-band Hubble Space Telescope observations taken as part of the Cluster Lensing And Supernova survey with Hubble. We find consistent weak distortion and magnification measurements of background galaxies and combine these signals to construct an optimally estimated radial mass profile of the cluster and its surrounding large-scale structure out to 5 Mpc h –1. We find consistency between strong-lensing and weak-lensing in the region where these independent data overlap, –1. The two-dimensional weak-lensing map reveals a clear filamentary structure traced by distinct mass halos. We model the lensing shear field with nine halos, including the main cluster, corresponding to mass peaks detected above 2.5σκ. The total mass of the cluster as determined by the different methods is Mvir ≈ (2.8 ± 0.4) × 1015 M☉. Although this is the most massive cluster known at z > 0.5, in terms of extreme value statistics, we conclude that the mass of MACS J0717.5+3745 by itself is not in serious tension with ΛCDM, representing only a ∼2σ departure above the maximum simulated halo mass at this redshift

  11. Implant-Supported Removable Partial Denture Improves the Quality of Life of Patients with Extreme Tooth Loss.

    Science.gov (United States)

    Campos, Camila Heitor; Gonçalves, Thais Marques Simek Vega; Garcia, Renata Cunha Matheus Rodrigues

    2015-10-01

    This study aimed to evaluate oral health-related quality of life (OHRQoL) in partially dentate subjects, presenting extreme tooth loss in posterior region with missing post-canines, comparing the use of conventional removable partial dentures (RPDs) and implant-supported RPDs. OHRQoL was measured using the Brazilian version of the Oral Health Impact Profile. Twelve subjects presenting maxillary total and mandibular Kennedy Class I edentulism (mean age 62.6±7.8 years) first received complete maxillary dentures and conventional mandibular free-end RPDs. After two months, the subjects had their OHRQoL assessed. Osseointegrated implants were inserted bilaterally in the mandibular first molar regions, and after four months ball abutments were placed to support the free-end RPD. Two months later, the patients had their OHRQoL reassessed. Wilcoxon signed-rank test was used to evaluate differences in OHRQoL (α=0.05). Results showed improvement in all OHIP-49 domains (p<0.05) after associating implants to the RPD. The mandibular implant-supported free-end RPD significantly improved OHRQoL. PMID:26647929

  12. A clinical study on the effectiveness of implant supported dental restoration in patients with chronic periodontal diseases.

    Science.gov (United States)

    Jiang, B Q; Lan, J; Huang, H Y; Liang, J; Ma, X N; Huo, L D; Xu, X

    2013-02-01

    This study evaluated the efficacy of implant supported dental restorations in patients with chronic periodontal diseases at various stages within 2 years of completing treatment. 30 patients with periodontal diseases and 30 patients without periodontal diseases were studied. Total counts of 276 implant bodies were divided into group A (patients with periodontal diseases; a total of 149 implants) and group B (patients with healthy periodontium; a total of 127 implants). In group A subjects, periodontitis was treated prior to implant placement. The study focused on patients' modified sulcus bleeding index, modified plaque index, implant mobility index, periodontal probing depth and implant success rate 12 and 24 months after the completion of the treatment. The result show: there were no significant differences in implant success rate between groups A and B; modified sulcus bleeding index scores showed differences between the groups 24 months after treatment; there were no significant differences in other clinical indexes during the study between the groups; there were no significant differences in periodontal probing depth between the groups; modified plaque index and modified sulcus bleeding index were positively correlated in implant supported dental restoration patients with chronic periodontal diseases.

  13. Real-time analysis of inflammatory cytokines and regulatory gene expression in tissues surrounding the hematoma after intracerebral hemorrhage

    Institute of Scientific and Technical Information of China (English)

    Longyi Chen; Yuchuan Xu; Zhenglin Yang; Fuqiang Guo; Xiaojia Li; Hong Yang; Yousong Yang; Hongyuan Dai; Yongsheng Wei; Yulan Huang; Hongbin Sun

    2008-01-01

    BACKGROUND: Secondary lesions can occur in tissues surrounding the hematoma following intracerebral hemorrhage, with the presence of inflammatory reactions, cytokine expression and apoptosis. These have been confirmed in animal studies. Our study sought to determine whether these could be detected in human tissues surrounding the hematoma following intracerebral hemorrhage. OBJECTIVE: To investigate expression of inflammatory cytokines, Bax and Bcl-x, and identify neural cell apoptosis in tissues surrounding the hematoma, and to analyze the correlation between them and pathological damage in intracerebral hemorrhage patients. DESIGN, TIME AND SETTING: This histopathology, controlled study was performed at the Department of Neurosurgery, Sichuan People's Hospital, China, from January 2003 to January 2005. PARTICIPANTS: Brain tissues I cm from the hematoma in 30 intracerebral hemorrhage patients sewed as the experimental group. Brain tissues located away from the hematoma in 7 patients served as the control group. METHODS: TUNEL was used to detect neural cell apoptosis, lmmunohistochemistry (labeled dextran polymer) and RT-PCR were used to measure tumor necrosis factor-α , interleukin-1β, interleukin-6, Bax and Bcl-x protein and mRNA expression. Pathological changes in brain tissues surrounding the hematoma were observed following HE staining. MAIN OUTCOME MEASURES: Neural cell apoptosis, inflammatory cytokines, Bax and Bcl-x protein and mRNA expression, pathological changes in brain tissues surrounding the hematoma. RESULTS: Brain tissues surrounding the hematoma were mildly damaged within 6 hours, severely damaged at 24-72 hours, and significantly improved 1 week following intracerebral hemorrhage. Expression of tumor necrosis factor-α protein and mRNA, interleukin-1 β and interleukin-6 mRNA was not significant in tissues surrounding the hematoma, which was identical to the control group within 6 hours after intracerebral hemorrhage. This expression was

  14. Fluorine analysis of human dentin surrounding resin composite after fluoride application by {mu}-PIGE/PIXE analysis

    Energy Technology Data Exchange (ETDEWEB)

    Okuyama, Katsushi, E-mail: katsu@den.hokudai.ac.jp [Graduate School of Dental Medicine, Hokkaido University, Department of Restorative Dentistry, Kita-13, Nishi-7, Kita-ku, Hokkaido, Sapporo 060-8586 (Japan) and School of Dentistry, University of North Carolina, Department of Operative Dentistry, 302 Brauer, CB 7450, Chapel Hill, NC 27599-7450 (United States); Komatsu, Hisanori [Graduate School of Dental Medicine, Hokkaido University, Department of Restorative Dentistry, Kita-13, Nishi-7, Kita-ku, Hokkaido, Sapporo 060-8586 (Japan); Yamamoto, Hiroko [Graduate School of Dentistry, Osaka University, 1-8 Yamada-Oka, Osaka, Suita 565-0871 (Japan); Pereira, Patricia N.R. [School of Dentistry, University of North Carolina, Department of Operative Dentistry, 302 Brauer, CB 7450, Chapel Hill, NC 27599-7450 (United States); Bedran-Russo, Ana K. [University of Illinois at Chicago, College of Dentistry, Department of Restorative Dentistry, 801 S. Paulina St., Chicago, IL 60612 (United States); Nomachi, Masaharu [Graduate School of Science, Osaka University, 1-1 Machikaneyama, Osaka, Toyonaka 560-0043 (Japan); Sato, Takahiro [TARRI, JAEA, Advanced Radiation Technology, 1233 Watanuki-machi, Gunma, Takasaki 370-1292 (Japan); Sano, Hidehiko [Graduate School of Dental Medicine, Hokkaido University, Department of Restorative Dentistry, Kita-13, Nishi-7, Kita-ku, Hokkaido, Sapporo 060-8586 (Japan)

    2011-10-15

    The use of fluoride for the prevention of caries is based on the transformation of hydroxylapatite to fluoroapatite in the presence of fluoride ions, thereby strengthening tooth structure. Adhesion of dentin and resin composite (tooth-colored restoration material) requires a dentin bonding system, since resin composite is not able to adhere to dentin directly. Demineralization of dentin by acid etching is an important step in the dentin bonding system, however, demineralization also introduces weaknesses in tooth structure. If the demineralized dentin could be strengthened by the application of fluoride, then the dentin-resin composite bond strength might also improve. To test this hypothesis, the present study evaluated the influence of fluoride applications on the strength of the dentin-resin composite bond by (1) tensile strength testing analyses, (2) SEM analyses of tooth structure, and (3) detection of calcium (Ca) and fluorine (F) distribution patterns by micro proton-induced X-ray emission ({mu}-PIXE) and micro proton-induced gamma-ray emission ({mu}-PIGE) analyses conducted at the Takasaki Ion Accelerators for Advanced Radiation Application (TIARA) at the Takasaki Advanced Radiation Research Institute (TARRI). In this study, the dentin in extracted human molars was exposed by grinding and the dentin was etched with 35% phosphoric acid. Fluoride was applied at two concentrations, 0.022% (100 ppm F) and 2.21% (10,000 ppm F) NaF solution, for two time periods, 30 and 60 s, prior to bonding the resin composite with the treated dentin. Controls were prepared in the same manner, but without the fluoride application. Bond strength was measured with a micro-tensile testing unit, and the fluorine and calcium distributions at the interface between dentin and resin composite were detected by {mu}-PIGE and {mu}-PIXE analysis, respectively. Results indicate that the 10,000 ppm F applications resulted in higher bond strengths than observed in either the 100 ppm F

  15. Fluorine analysis of human dentin surrounding resin composite after fluoride application by μ-PIGE/PIXE analysis

    Science.gov (United States)

    Okuyama, Katsushi; Komatsu, Hisanori; Yamamoto, Hiroko; Pereira, Patricia N. R.; Bedran-Russo, Ana K.; Nomachi, Masaharu; Sato, Takahiro; Sano, Hidehiko

    2011-10-01

    The use of fluoride for the prevention of caries is based on the transformation of hydroxylapatite to fluoroapatite in the presence of fluoride ions, thereby strengthening tooth structure. Adhesion of dentin and resin composite (tooth-colored restoration material) requires a dentin bonding system, since resin composite is not able to adhere to dentin directly. Demineralization of dentin by acid etching is an important step in the dentin bonding system, however, demineralization also introduces weaknesses in tooth structure. If the demineralized dentin could be strengthened by the application of fluoride, then the dentin-resin composite bond strength might also improve. To test this hypothesis, the present study evaluated the influence of fluoride applications on the strength of the dentin-resin composite bond by (1) tensile strength testing analyses, (2) SEM analyses of tooth structure, and (3) detection of calcium (Ca) and fluorine (F) distribution patterns by micro proton-induced X-ray emission (μ-PIXE) and micro proton-induced gamma-ray emission (μ-PIGE) analyses conducted at the Takasaki Ion Accelerators for Advanced Radiation Application (TIARA) at the Takasaki Advanced Radiation Research Institute (TARRI). In this study, the dentin in extracted human molars was exposed by grinding and the dentin was etched with 35% phosphoric acid. Fluoride was applied at two concentrations, 0.022% (100 ppm F) and 2.21% (10,000 ppm F) NaF solution, for two time periods, 30 and 60 s, prior to bonding the resin composite with the treated dentin. Controls were prepared in the same manner, but without the fluoride application. Bond strength was measured with a micro-tensile testing unit, and the fluorine and calcium distributions at the interface between dentin and resin composite were detected by μ-PIGE and μ-PIXE analysis, respectively. Results indicate that the 10,000 ppm F applications resulted in higher bond strengths than observed in either the 100 ppm F applications or

  16. Peri-implant biomechanical responses to standard, short-wide, and mini implants supporting single crowns under axial and off-axial loading (an in vitro study).

    Science.gov (United States)

    Kheiralla, Lamia Sayed; Younis, Jihan Farouk

    2014-02-01

    This study compared the biomechanical responses of 3 single crowns supported by 3 different implants under axial and off-axial loading. A standard implant (3.75 mm diameter, 13 mm length), a mini implant (3 mm diameter, 13 mm length), and a short-wide implant (5.7 mm diameter, 8 mm length) were embedded in epoxy resin by the aid of a surveyor to ensure their parallelism. Each implant supported a full metal crown made of Ni-Cr alloy with standardized dimensions. Strain gauges and finite element analysis (FEA) were used to measure the strain induced under axial and off-axial functional loads of 300 N. Results showed that mini implants recorded the highest microstrains, under both axial and off-axial loading. All implants showed a considerable increase in strain values under off-axial loading. Standard and short-wide implants proved to be preferable in supporting crowns, as the standard implant showed the lowest strains under axial and off-axial loading using FEA simulation, while the short-wide implant showed the lowest strains under nonaxial loading using strain gauge analysis.

  17. Effects of different designs of implant supported fixed partial dentures on peri-implant bone stress distribution during mandibular-flexture

    Directory of Open Access Journals (Sweden)

    Nokar S.

    2004-08-01

    Full Text Available Statement of Problem: In the treatment of edentulous patients with implant supported fixed partial dentures several factors such as implant numbers, implant position, superstructure pattern and cantilever length must be considered. Mandibular flexture in function exerts forces in peri-implant bone, however; this phenomenon has received little attention. Purpose: The goal of this finite element analysis (FEA study was to evaluate the effect of mandibular dimensional changes on peri-implant bone stress in different prosthesis and implant treatment plans. Materials and Methods: In this experimental study, three dimensional finite element computer model of mandible was simulated according to data from CT-Scan in 0.5 mm sections. The model of 4.110 mm ITI implant, measured by profile projector, was simulated in solid works 2003 software. Implant models were inserted, in two different patterns, on mandible and three different superstructures were placed on implants. Two clenching tasks were modeled (incisal clench and right molar clench. Results: Analysis of Von Misses stress for peri-implant bone revealed the lowest stress values in three-piece superstructure. Conclusion: According to this study, additional placement of implants in order to fabricate independent prostheses and to achieve the freedom of mandibular flexture are recommended.

  18. Intelligent direct analysis of physical and mechanical parameters of tunnel surrounding rock based on adaptive immunity algorithm and BP neural network

    Institute of Scientific and Technical Information of China (English)

    Xiao-rui Wang; Yuan-han Wang; Xiao-feng Jia

    2009-01-01

    Because of complexity and non-predictability of the tunnel surrounding rock, the problem with the determination of the physical and, mechanical parameters of the surrounding rock has become a main obstacle to theoretical research and numerical analysis in tunnel engineering. During design, it is a frequent practice, therefore, to give recommended values by analog based on experience. It is a key point in current research to make use of the displacement back analytic method to comparatively accurately determine the parameters of the surrounding rock whereas artificial intelligence possesses an exceptionally strong capability of identifying, expressing and coping with such complex non-linear relationships. The parameters can be verified by searching the optimal network structure, using back analysis on measured data to search optimal parameters and performing direct computation of the obtained results. In the current paper, the direct analysis is performed with the biological emulation system and the software of Fast Lagrangian Analysis of Continua (FLAC3D. The high non-linearity, network reasoning and coupling ability of the neural network are employed. The output vector required of the training of the neural network is obtained with the numerical analysis software. And the overall space search is conducted by employing the Adaptive Immunity Algorithm. As a result, we are able to avoid the shortcoming that multiple parameters and optimized parameters are easy to fall into a local extremum. At the same time, the computing speed and efficiency are increased as well. Further, in the paper satisfactory conclusions are arrived at through the intelligent direct-back analysis on the monitored and measured data at the Erdaoya tunneling project. The results show that the physical and mechanical parameters obtained by the intelligent direct-back analysis proposed in the current paper have effectively unproved the recommended values in the original prospecting data. This is of

  19. [Observations and comparison analysis of air pollution in Beijing and nearly surrounding areas during Beijing 2008 Olympic Games].

    Science.gov (United States)

    Sun, Zhi-Qiang; Ji, Dong-Sheng; Song, Tao; Lin, Hong; Wang, Yue-Si; Jiang, Chang-Sheng

    2010-12-01

    In order to study regional air quality, evaluate the interaction of air quality among Beijing and four cities and assess the effects of regional collaborative emission abatement in Beijing and surrounding areas for the Olympic Games period on regional air quality, and seek an effective means of early warning of air pollution, a monitoring network on observation of atmospheric pollutants in Beijing and four nearby cities which were Zhuozhou, Langfang, Xianghe and Yanjiao, was established to measure concentrations of NO(x), O3 and particulate matter in June 2008. The results show that the primary pollutants in Beijing and nearly surrounding areas are particulates during the study periods. The average mass concentrations of PM10 were (114 +/- 66) microg/m3 and (128 +/- 59) microg/m3 in Beijing and nearby cities, respectively, while the average mass concentrations of PM2.5 were (77 +/- 47) microg/m3 and (81 +/- 51) microg/m3, respectively. The average maximum hourly mass concentrations of O3 were (164 +/- 52) microg/m3 and (165 +/- 55) microg/m3, as well as the average mass concentrations of NO(x) were (58 +/- 23) microg/m3 and (25 +/- 14) microg/m3 in Beijing and nearby cities, respectively. Compared to June, concentrations of PM10, PM2.5, O3, NO(x) decreased by 69%, 62%, 18% and 41% during the Olympic period (from August 8 to 24) and 56%, 49%, 17% and 16% during the Paralympic Games period (from September 6 to 17) in Beijing. The mass concentration of PM2.5 was affected by the surrounding areas of Beijing seriously. The relative high concentrations of NO(x) in Beijing implied NO(x) had the potential tendency to be transported to the surrounding areas. Ozone showed regional pollution characteristics in summer. It shows that the monitoring network on observation of atmospheric pollutants in Beijing and nearly surrounding areas is significant in early warning of air pollution, and could provide scientific support for interregional cooperation of air pollution control.

  20. Importance of a distal proximal contact on load transfer by implant-supported single adjacent crowns in posterior region of the mandible: a photoelastic study

    Directory of Open Access Journals (Sweden)

    Fabio Afranio de Aguiar Junior

    2013-09-01

    Full Text Available OBJECTIVE: This study aimed to evaluate the importance of a distal proximal contact on the load transfer to the posterior region of the mandible by non-splinted adjacent implant-supported crowns using photoelastic stress analysis. MATERIAL AND METHODS: A rectangular model (68x30x15 mm was made of polymethylmethacrylate resin to simulate half of the mandibular arch. One model was completed with resin replicas representing the first premolar and second molar and with two 3.75 mm dia.x11 mm internal hexagon threaded implants replacing the second premolar and first molar. The other model was manufactured in the same way but without the second molar. Both models were duplicated using photoelastic resin. The roots of the teeth replicas were covered with a layer of polyether impression material to simulate the periodontal ligament. Two different vertical loads were applied to the crowns as follows: 1 - single static point load alternately applied to the crowns replacing the second premolar and first molar (50 N; 2 - simultaneous static point loads applied to both of the crowns replacing the second premolar and first molar (100 N. The resulting isochromatic fringe pattern in the photoelastic model was monitored and photographed. RESULTS: All loading conditions studied showed that the presence of the second molar has changed the load transmission and the pattern of stresses. CONCLUSION: Results showed that the presence of a second molar proximal contact can help minimize the stresses around the implants.

  1. Microfractures in metal-ceramic and all-ceramic implant-supported fixed dental prostheses caused by superstructure fixation.

    Science.gov (United States)

    Karl, Matthias; Graef, Friedrich; Wichmann, Manfred; Beck, Nina

    2012-01-01

    The effect of ceramic veneering on the passivity of fit of cast metal and CAD/CAM-fabricated zirconia ceramic implant-supported three-unit cement-retained restorations was investigated, as well as the effect of misfit stress on the marginal integrity of ceramic veneers. Superstructures were fabricated using cast metal or by CAD/CAM milling of presintered or HIP zirconia ceramic (n=10). Before and after veneering, strain gages were used to measure in vitro the strain developed in all the restorations as a result of superstructure fixation. Fluorescent penetrant method was used to detect microcracks developed in ceramic veneers. Cast frameworks showed significantly higher strain values than CAD/CAM frameworks (p=0.000). Veneering significantly increased strain development in all CAD/CAM frameworks (p=0.000). Compared to zirconia ceramic restorations, significantly more microcracks were observed in cast restorations (p=0.000) both before and after superstructure fixation. PMID:22673463

  2. Implant-supported overdentures, a prevention of bone loss in edentulous mandibles? A 5-year follow-up study

    DEFF Research Database (Denmark)

    von Wowern, N; Gotfredsen, K

    2001-01-01

    the implants and 3) whether the presence of mandibular osteoporosis affects the loss of bone height around the implants. The material consisted of 22 long-term edentulous healthy persons, 18 women and 4 men from 54 to 78 years of age with 1 Astra Tech Dental Implant in both canine regions, connected by a bar......The purpose of this study were to analyse 1) the changes in the bone mineral content (BMC) in mandibles with implant-supported overdentures when compared with the physiologic age-related mandibular BMC loss, 2) whether the BMC changes were different in groups without or with a bar connecting...... of bone height around implants was measured on periodically identical intraoral radiographs. The fixed parts of the implant-system were stable during the trial in all patients. In conclusion: 1) the increased function after this treatment seems to cause a load-related bone formation which minimizes...

  3. Prosthetic Management of an Extensive Maxillary Alveolar Resorption with an Implant-supported Restoration: a Technical Report

    Directory of Open Access Journals (Sweden)

    Fariborz Saadat

    2013-01-01

    Full Text Available Despite the recent developments in peri-implant surgical regenerative procedures, re-establishing the hard and soft tissue contour is still a challenge in cases with severe ridge deficiency. It becomes more difficult when incorrectly placed implants cause screw connections to come out onto the labial surfaces of the teeth. A two-part maxillary implant supported fixed restoration was constructed. The first part was consisted of a screw retained sub-structure that replaced gingival portions of the deficient maxilla and the second part was a cement retained super-structure that reconstructed the anatomical crowns of the lost teeth. In this way awkwardly placed implants did not interfere with the desired esthetic result. Another great advantage was that the alterations or repairs on cemented crowns can easily be carried out without compromising the entire construction.

  4. Perturbation Analysis on Guided Waves in a Fluid-Filled Borehole Surrounded by a Cubic Crystal Anisotropic Medium

    Institute of Scientific and Technical Information of China (English)

    ZHANG Li; ZHANG Bi-Xing; WANG Ke-Xie

    2007-01-01

    The perturbation method is employed to analyse the guided waves in a borehole surrounded by a cubic crystal medium for the Srst time. The cubic crystal medium is regarded as a reference unperturbed isotropic state added to the perturbation. The dispersion characteristics of Stoneley wave, pseudo-Rayleigh wave, Hexural wave, and screw wave are investigated in detail. It is found that dispersion of the guided waves excited by monopole and dipole sources does not depend on the azimuth of the source, whereas the dispersion of screw wave excited by quadrupole source is significantly related to the azimuth of the source. Screw waves propagated along different azimuth in the borehole can be split. This is different from screw waves in transversely isotropic media (hexagonal crystal), which have been widely studied.

  5. Effect of screw access hole preparation on fracture load of implant-supported zirconia-based crowns: an in vitro study.

    Science.gov (United States)

    Mokhtarpour, Hadi; Eftekhar Ashtiani, Reza; Mahshid, Minoo; Tabatabaian, Farhad; Alikhasi, Marzieh

    2016-01-01

    Background. Fracture load of implant-supported restorations is an important factor in clinical success. This study evaluated the effect of two techniques for screw access hole preparation on the fracture load of cement-screw-retained implant-supported zirconia-based crowns. Methods. Thirty similar cement-screw-retained implant-supported zirconia-based maxillary central incisor crowns were evaluated in three groups of 10. Group NH: with no screw access holes for the control; Group HBS: with screw access holes prepared with a machine before zirconia sintering; Group HAS: with screw access holes prepared manually after zirconia sintering. In group HBS, the access holes were virtually designed and prepared by a computer-assisted design/computer-assisted manufacturing system. In group HAS, the access holes were manually prepared after zirconia sintering using a diamond bur. The dimensions of the screw access holes were equal in both groups. The crowns were cemented onto same-size abutments and were then subjected to thermocycling. The fracture load values of the crowns were measured using a universal testing machine. Data were analyzed with ANOVA and Tukey test (P implant-supported zirconia-based crowns decreased the fracture load. PMID:27651885

  6. Influence of implant position on clinical crown length and peri-implant soft tissue dimensions at implant-supported single crowns replacing maxillary central incisors

    DEFF Research Database (Denmark)

    Peng, Min; Fei, Wei; Hosseini, Mandana;

    2013-01-01

    The aims of the present study were to evaluate the influence of implant position on clinical crown length and marginal soft tissue dimensions at implant-supported single crowns of maxillary central incisors, and to validate the papilla index score (PIS). Twenty-five patients, who had lost one...

  7. Influence of patient age on the success rate of dental implants supporting an overdenture in an edentulous mandible : A 3-year prospective study

    NARCIS (Netherlands)

    Meijer, HJA; Batenburg, RHK; Raghoebar, GM

    2001-01-01

    The aim of this study was to determine the influence of age on peri-implant tissues in patients treated with implant-supported overdentures in the mandible. A prospective study was carried out with 2 groups of healthy edentulous patients. The mean age of the younger group (n = 32) was 46 years (rang

  8. The optimal design of an implant to improve bone quality of implant surroundings based on stress analysis

    Energy Technology Data Exchange (ETDEWEB)

    Noyama, Yoshihiro; Kuramoto, Koichi [Nakashima Medical Division, Nakashima Propeller Co., Ltd., 688-1 Joto-Kitakata, Okayama-shi, Okayama 700-8691 (Japan); Nagayama, Noriyuki [Department of Mechanical Engineering, Applied Electronics Group Industrial Technology Centre of Okayama Prefecture, 5301 Haga, Okayama 701-1296 (Japan); Nakano, Takayoshi [Division of Materials and Manufacturing Science, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan)], E-mail: nakano@mat.eng.osaka-u.ac.jp

    2009-05-01

    Research on how implant surface shape contributes to long-term stability after implantation is important in the field of orthopaedics. In particular, technology that controls various bone quality parameters and voluntary bone inducement in implant surroundings should be developed for the next generation of implants and this will improve the patient's quality of life (QOL). For this research, we focused on the inducement of the appropriate alignment for biological apatite (BAp) crystallites and related collagen (Col.) fibres as a bone quality parameter. In this study, we predicted that when stress is applied to bone, the BAp/Col. preferential alignment can be formed if osteocytes are in an environment that is aligned with the principle stress vector. We tested this idea by introducing grooves in the principal stress direction on the surface of an implant. This work thus analyzes the effect of stress transmission by a load at the proximal femur on the bone inside and near the grooves by using mechanical simulation in which groove angles can be changed on the implant surface. Coordinate data from the mechanical simulation of the combined bone/implant environment was verified against the coordinate data obtained by CT scans of actual canine bone. Results suggest that the tendency of stress transmission differs depending on the position and angle of the grooves and based on a vector diagram of the maximum and minimum principal stresses. The simulation was able to predict bone dynamics in vivo and enabled a best design of an implant to control the BAp/Col. alignment as an index of bone quality.

  9. The optimal design of an implant to improve bone quality of implant surroundings based on stress analysis

    Science.gov (United States)

    Noyama, Yoshihiro; Nagayama, Noriyuki; Kuramoto, Koichi; Nakano, Takayoshi

    2009-05-01

    Research on how implant surface shape contributes to long-term stability after implantation is important in the field of orthopaedics. In particular, technology that controls various bone quality parameters and voluntary bone inducement in implant surroundings should be developed for the next generation of implants and this will improve the patient's quality of life (QOL). For this research, we focused on the inducement of the appropriate alignment for biological apatite (BAp) crystallites and related collagen (Col.) fibres as a bone quality parameter. In this study, we predicted that when stress is applied to bone, the BAp/Col. preferential alignment can be formed if osteocytes are in an environment that is aligned with the principle stress vector. We tested this idea by introducing grooves in the principal stress direction on the surface of an implant. This work thus analyzes the effect of stress transmission by a load at the proximal femur on the bone inside and near the grooves by using mechanical simulation in which groove angles can be changed on the implant surface. Coordinate data from the mechanical simulation of the combined bone/implant environment was verified against the coordinate data obtained by CT scans of actual canine bone. Results suggest that the tendency of stress transmission differs depending on the position and angle of the grooves and based on a vector diagram of the maximum and minimum principal stresses. The simulation was able to predict bone dynamics in vivo and enabled a best design of an implant to control the BAp/Col. alignment as an index of bone quality.

  10. Analysis on the stress of the bone surrounding mini-implant with different diameters and lengths under torque.

    Science.gov (United States)

    Lu, Yingjuan; Chang, Shaohai; Ye, Jiantao; Ye, Yushan; Yu, Yansong

    2015-01-01

    The purpose of this study is to compare the stress of the bone around the mini-implant under the two kinds of force: the composite force which contains torque and traditional single force. There were 96 finite element models formed by the combination of mini-implant and bone, with diameters of 1.2 mm, 1.6 mm, 2.0 mm and corresponding length being 6 mm, 8 mm, 10 mm, 12 mm, respectively. Each size corresponded to 8 models. Group SF (each size n=4) was loaded with 200 g single force, while Group CF (each size n=4) was loaded with composite force which contained 6N mm torque and 200 g single force. The maximum equivalent stress (Max EQS) of the bone surrounding mini implant with different loading directions was calculated, and the relationship of force direction, diameter and length was also evaluated. The Max EQS of Group CF was higher than that of Group SF. The effect of force direction on the stress was related to the diameter of mini implant, but had nothing to do with its length. The Max EQS of the cortical bone around mini implant in Group CF was higher (Pdifference (P>0.05) between Group SF and Group CF in terms of bone stress when the diameter of mini implant was 1.6 mm or 2.0 mm. In our study, it is demonstrated that the diameter of mini-implant is better to be larger than 1.2 mm when a mini-implant is used in a torque control of tooth. The impact of this feature in the clinical setting needs to be verified.

  11. The optimal design of an implant to improve bone quality of implant surroundings based on stress analysis

    International Nuclear Information System (INIS)

    Research on how implant surface shape contributes to long-term stability after implantation is important in the field of orthopaedics. In particular, technology that controls various bone quality parameters and voluntary bone inducement in implant surroundings should be developed for the next generation of implants and this will improve the patient's quality of life (QOL). For this research, we focused on the inducement of the appropriate alignment for biological apatite (BAp) crystallites and related collagen (Col.) fibres as a bone quality parameter. In this study, we predicted that when stress is applied to bone, the BAp/Col. preferential alignment can be formed if osteocytes are in an environment that is aligned with the principle stress vector. We tested this idea by introducing grooves in the principal stress direction on the surface of an implant. This work thus analyzes the effect of stress transmission by a load at the proximal femur on the bone inside and near the grooves by using mechanical simulation in which groove angles can be changed on the implant surface. Coordinate data from the mechanical simulation of the combined bone/implant environment was verified against the coordinate data obtained by CT scans of actual canine bone. Results suggest that the tendency of stress transmission differs depending on the position and angle of the grooves and based on a vector diagram of the maximum and minimum principal stresses. The simulation was able to predict bone dynamics in vivo and enabled a best design of an implant to control the BAp/Col. alignment as an index of bone quality.

  12. Effect of Luting Agents on Retention of Dental Implant-Supported Prostheses.

    Science.gov (United States)

    Pan, Yu-Hwa; Lin, Tai-Min; Liu, Perng-Ru; Ramp, Lance C

    2015-10-01

    To evaluate the retentive strength of 7 different luting agents in cement-retained implant abutment/analog assemblies. Fifty-six externally hexed dental implant abutment/analog assemblies and cast superstructures were divided randomly into 7 groups for cementation with each of the 7 luting agents. Five definitive cements tested were zinc phosphate cement, All-Bond 2, Maxcem, RelyX Luting cement, HY-Bond, and two provisional cements, ImProv and Premier. Cast superstructures were cemented onto the implant abutments and exposed to 1000 thermal cycles (0°C-55°C) and 100 000 cycles on a chewing simulator (75 N load). A universal testing machine was used to measure cement failure load of the assembled specimens. Cement failure load was evaluated with 1-way ANOVA and Duncan's multiple range analysis. Significant differences in cement failure loads were measured (P zinc phosphate cement were analogous, and higher than HY-Bond. Improv and Premier constituted a pair, which demonstrated the lowest retentive values. Within the limitations of this in vitro study, Maxcem and All-Bond 2 are good candidates for cement-retained implant prostheses while concerning retention. PMID:24666355

  13. Retention Strength after Compressive Cyclic Loading of Five Luting Agents Used in Implant-Supported Prostheses

    Directory of Open Access Journals (Sweden)

    Angel Alvarez-Arenal

    2016-01-01

    Full Text Available The purpose of this study was to evaluate and compare the retention strength of five cement types commonly used in implant-retained fixed partial dentures, before and after compressive cyclic loading. In five solid abutments screwed to 5 implant analogs, 50 metal Cr-Ni alloy copings were cemented with five luting agents: resin-modified glass ionomer (RmGI, resin composite (RC, glass ionomer (GI, resin urethane-based (RUB, and compomer cement (CC. Two tensile tests were conducted with a universal testing machine, one after the first luting of the copings and the other after 100,000 cycles of 100 N loading at 0.72 Hz. The one way ANOVA test was applied for the statistical analysis using the post hoc Tukey test when required. Before and after applying the compressive load, RmGI and RC cement types showed the greatest retention strength. After compressive loading, RUB cement showed the highest percentage loss of retention (64.45%. GI cement recorded the lowest retention strength (50.35 N and the resin composite cement recorded the highest (352.02 N. The type of cement influences the retention loss. The clinician should give preference to lower retention strength cement (RUB, CC, and GI if he envisages any complications and a high retention strength one (RmGI, RC for a specific clinical situation.

  14. Comparison of Maxillary Implant-Supported Prosthesis in Irradiated and Non-Irradiated Patients

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Summary: In order to investigate the influence of radiation therapy after the treatment of maxillaryimplant-supported prostheses, 27 patients received a total of 131 implants in maxilla after oral cancertreatment and/or reconstructive surgery. Among them, 25 received maxillary implant-supportedprostheses. The cumulative survival rates of implants and prostheses were evaluated by the product-limit-estimates method according to Kaplan-Meier. The cumulative survival rate of implants andprostheses in irradiated patients was compared with that in non-irradiated patients by statistical Log-rank test. The results showed that 112 implants were observed after implant loading. The implantscumulative survival rate was approximately 65 % for overall patients. The cumulative prosthesis suc-cessful rate was approximately 88 % for all 25 patients. Log-rank test analysis revealed that therewas a significant difference in cumulative implants survival rates between non-irradiated and irradiat-ed maxillary bone (P<0. 01). It was concluded that the implants and prostheses in irradiated pa-tients have significantly lower survival rates than in non-irradiated patients.

  15. The effect of casting and masticatory simulation on strain and misfit of implant-supported metal frameworks.

    Science.gov (United States)

    Bhering, Cláudia Lopes Brilhante; Marques, Isabella da Silva Vieira; Takahashi, Jessica Mie Ferreira Koyama; Barão, Valentim Adelino Ricardo; Consani, Rafael Leonardo Xediek; Mesquita, Marcelo Ferraz

    2016-05-01

    The influence of casting and masticatory simulation on marginal misfit and strain in multiple implant-supported prostheses was evaluated. Three-unit screw retained fixed dental prosthesis (FDP) and screw retained full-arch fixed dental prosthesis (FAFDP) frameworks were made using calcinable or overcasted cylinders on conical dental implant abutment. Four groups were obtained according to the cylinder and prosthesis type (n=10). Frameworks were casted in CoCr alloy and subjected to strain gauge analyses and marginal misfit measurements before and after 10(6) mechanical cycles (2 Hz/280 N). Results were submitted to ANOVA, Tukey's HSD and Pearson correlation test (α=0.05). No difference was found on misfit among all groups and times (p>0.05). Overcasted frameworks showed higher strain than the calcinable ones (FDP - Initial p=0.0047; Final p=0.0004; FAFDP - Initial p=0.0476; Final p=0.0115). The masticatory simulation did not influence strain (p>0.05). No correlation was observed between strain and misfit (r=0.24; p>0.05). In conclusion, the marginal misfit value in the overcasted full-arch frameworks was higher than clinical acceptable data. It proved that overcasted method is not an ideal method for full-arch prosthesis. Overcasted frameworks generate higher strain upon the system. The masticatory simulation had no influence on misfit and strain of multiple prostheses. PMID:26952480

  16. Effect of pontic framework design on the fracture resistance of implant-supported all-ceramic fixed partial dentures

    Directory of Open Access Journals (Sweden)

    Ozgur Inan

    2009-10-01

    Full Text Available OBJECTIVE: The purpose of this study was to compare the fracture resistance of implant-supported all-ceramic fixed partial dentures, which have three different pontic designs. MATERIAL AND METHODS: Two implants were placed in a metal model simulating mandibular left second premolar and mandibular left second molar. Thirty standardized 3-unit all-ceramic fixed partial dentures with biconvex, convex or concave pontic designs were fabricated using IPS e.max system (n=10. Afterwards, specimens were centrally loaded on the pontics until failure with a universal testing machine. Results were analyzed by Kruskal-Wallis and Mann-Whitney U tests at 5% significance level. RESULTS: The fracture resistance values of all-ceramic fixed partial dentures designed with biconvex, convex or concave pontics were 349.71, 438.20 and 300.78 N, respectively. There were no statistically significant differences between the fracture resistances of the groups (p>0.05, except for convex and concave groups (p<0.05 and p=0.009, respectively. CONCLUSIONS: Convex design showed the best mechanical properties as demonstrated by the high values of fracture resistance.

  17. The Effect of Abutment Surface Roughness on the Retention of Implant-Supported Crowns Cemented with Provisional

    Directory of Open Access Journals (Sweden)

    Seyyed Mohammad Abrisham

    2012-09-01

    Full Text Available Introduction: Surface roughness can increase the retention of castings by ridges and grooves that are microretentive. This study compared the retention of implant-supported crowns when used with 3 different surface roughness abutments and one temporary cement. Methods: Thirty solid abutments (ITI, 4 mm high, were divided into three groups randomly. In the first group, 10 abutments were roughened with sandblast (50-µm aluminum oxide and in the second group, 10 abutments were roughened with diamond bur. The third group had no surface treatment. Then, thirty implant fixture analogs (ITI were placed in the center of acrylic cylinders. After that a solid abutment was tightened on the each fixture analog with 35 N/cm force. Thirty base metal crowns were made on the 4 mm ITI abutment analogs using plastic coping. The prepared copings were cemented on the abutments by TempBond temporary cement and finally, crowns were pulled from the abutment in a universal test machine at a cross speed of 0.5cm/min. Results: The mean tensile strength in sandblasted, bur treated, and control group were 64.38±8, 91.37±7.19, and 58.61±1.93, respectively. Bur treated group showed higher tensile strength in comparison with two other groups. Conclusion: Surface modification of implant abutment by diamond bur may be an effective method to increase retention of crown when TempBond is used.

  18. Loosening torque of prosthetic screws in metal-ceramic or metal-acrylic resin implant-supported dentures with different misfit levels.

    Science.gov (United States)

    Bacchi, Ataís; Paludo, Litiane; Ferraz Mesquita, Marcelo; Schuh, Christian; Federizzi, Leonardo; Oro Spazzin, Aloísio

    2013-04-26

    The aim of this study was to evaluate the effect of the prosthesis material (metal-acrylic resin or metal-ceramic) on loosening torque of the prosthetic screws in an implant-supported mandibular denture under two levels of vertical misfit. Ten frameworks were fabricated with commercially pure titanium, and five of them received acrylic resin and acrylic artificial teeth as veneering material and the other five were veneered with porcelain. Two levels of vertical fit were also created by fabricating 20 cast models to obtain four experimental groups according to the prosthesis material and misfit: Group 1 (metal-acrylic resin prosthesis with a passive fit); Group 2 (metal-acrylic resin prosthesis with a non-passive fit); Group 3 (metal-ceramic prosthesis with a passive fit); and Group 4 (metal-ceramic prosthesis with a non-passive fit). Two hundred prosthetic titanium-alloy screws were divided in 40 sets (five screws per set, n=10). After 24h, the loosening torque of the screws was evaluated using a digital torque meter. The results were submitted to two-way ANOVA analysis of variance followed by a Tukey's test (α=0.05). The mean values and standard deviations for each group were G1=7.05 (1.64), G2=5.52 (0.90), G3=6.46 (1.34), and G4=4.35 (0.99). Overall, the prosthesis material and misfit factors showed a statistically significant influence on the loosening torque (p<0.05). Metal-ceramic prosthesis and misfits decreased the loosening of the torque of the prosthetic screws.

  19. Clinical outcome of implant-supported all-ceramic fixed partial prostheses for posterior tooth restoration%氧化锆全瓷固定桥在后牙种植修复中的临床效果观察

    Institute of Scientific and Technical Information of China (English)

    解涓; 林盛筱; 谢超; 刘艳; 宋应亮; 马威; 李德华

    2014-01-01

    目的:对氧化锆全瓷固定桥在后牙种植区的临床应用效果进行初步评估。方法:随访2011-07~2012-06采用种植体支持的全瓷固定桥修复后牙缺失的47位患者(53个修复体,共120枚种植体)的临床资料。记录种植体的失败数量、修复体失败数量、机械及生物并发症情况。结果:37例43个修复体、100个种植体随访12~24个月。随访病例中共有9个修复体(20.9%)出现崩瓷,9颗种植体(9.0%)存在种植体周围黏膜炎。修复体存留率100%,种植体存留率100%。所有种植体和修复体均未出现松动、脱落、折断等现象。结论:种植体支持的氧化锆全瓷固定桥用于后牙种植修复是可行的。%Objective:To evaluate the outcome of implant-supported all-ceramic fixed partial prostheses (FPPs)in posterior area. Methods:The clinical data of 1 20 implants-supported 53 fixed dentures in 47 patients were collected from July 201 1 to June 201 2 and prospectively studied.Complication and failure of implants and /or prosthesis,biological and technical complications were evaluated. Results:43 restorations with 1 00 implants in 37 cases were followed up for 1 2 -24 months.Veneering ceramic chipping was observed in 9(20.9%)prostheses.Inflamed marginal gingivitis was found around 3(7.0%)prostheses.No implant was involved in technical complication.Cumulative survival rate was 1 00% for implant-based analysis and 1 00% for prostheses-based analysis.Conclusion:Implant-supported all-ceramic fixed partial dentures may be a feasible treatment modality for posterior dental restoration.

  20. Combined Method of 3d Analysis for Underground Structures in View of Surrounding Infinite Homogeneous and Inhomogeneous Medium

    Directory of Open Access Journals (Sweden)

    N.V. Chernysheva

    2016-08-01

    Full Text Available The application of algorithms of the finite element method (FEM or the boundary element method (BEM reveals some peculiar properties for a numerical solution of the three-dimensional analysis in infinite domains. Various algorithms offer to avoid such problems at the expense of combining different methods and equations. The algorithm of the 3d analysis developed to solve an external boundary problem by applying the combined method based on incorporating the FEM and Somigliana’s integral formula is considered. The algorithm is modified for the case of the interaction of a structure with an inhomogeneous medium. The efficiency of software implementation of both algorithms has been tested. A stress-strain analysis of an inhomogeneous medium with a cavity has been carried out to illustrate the given approach.

  1. A Spatial Hedonic Analysis of the Effects of Wind Energy Facilities on Surrounding Property Values in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Hoen, Ben [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Wiser, Ryan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Cappers, Peter [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Brown, Jason P. [Federal Reserve Bank of Kansas City, MO (United States); Jackson, Thomas [Real Analytics Inc. and Texas A & M Univ., College Station, TX (United States); Thayer, Mark A. [San Diego State Univ., CA (United States)

    2013-08-21

    This report summarizes a new analysis, building on previously published research, about wind energy’s effects on residential property values. This study helps fill research gaps by collecting and analyzing data from 27 counties across nine U.S. states, related to 67 different wind facilities, and constructs a pooled model that investigates average effects near the turbines across the sample while controlling for local variables, such as sale prices of nearby homes.

  2. Satellite Images Analysis of Temporal Change (1979-2000) of the Mangrove Covertures that Surround the Mandinga Coastal Lagoon, Mexico.

    Science.gov (United States)

    Aldeco-Ramírez, J.; Cervantes-Candelas, A.

    2007-05-01

    Knowledge about the historical condition of the resources and the risk of natural hazards is an urgent necessity in developing countries. Satellite images analysis was applied in this study in order to evaluate coverture changes between 1979 and 2000. Mangroves cover large areas of coastal lagoon shoreline in the tropics and subtropics where they are important components in the productivity and integrity of their ecosystems. Visual and digital analysis of satellite images have been applied since the seventies when the first Land sat satellite was put in orbit. The digital analysis technique is mainly based on the reflectance or spectral response of the different objects laid on the earth surface as captured by the satellite. The results are useful for the environmental assessment of natural resources as forest and crops, and the quantification of hazards as fires, plagues, deforestation and urban expansion. This research surveys satellite images from the Mandinga Lagoon System, a coastal lagoon located to the south of the main port of Veracruz (19.1N, 96.1W), during three periods: 1989 1999 and 2000. The mangrove foliar cover was analyzed throughout the time. The reflectance signal of the mangrove that encircles the lagoon was taken as a base line for reference. The normalized difference vegetation index (NDVI) was computed in order to classify the vegetal coverage along the time. From our analysis we obtained that from 1979 to 1990 and from 1990 to 2000 areas of 122 hectares (approx. 305 acres) and 202 hectares (approx. 505 acres) were lost, respectively. The rates of mangrove trimming of 11.1 and 20.2 hectares yr-1 are high compared with other coastal lagoons of Mexico. The main causes of this deforestation are also discussed along with other factors as, the change of use of land and the fishery declination.

  3. The Effects of New Design of Access Hole on Porcelain Fracture Resistance of Implant-Supported Crowns

    Directory of Open Access Journals (Sweden)

    Reza Derafshi

    2015-03-01

    Full Text Available Statement of the Problem: One disadvantage of cement-retained crowns is the lack of predictable irretrievability. This problem can be overcome through designing a screw access hole in the metal substructure of cement-retained restora-tion and using porcelain stain to define this area. Purpose: This study aimed to evaluate the influence of existence of screw access hole on porcelain fracture resistance of metal-ceramic implant-supported crowns. Materials and Method: Thirty six standardized metal-ceramic crowns were fabri-cated and divided into 3 groups (n=12; group 1 conventional cement-retained metal-ceramic crowns as control group, group 2 cement-retained MC crowns in which porcelain stain was used to define the location of screw access channel, and group 3 cement-retained metal-ceramic crowns in the metal substructure of which a hole and ledge was designed in the location of screw access channel. The specimens were cemented (TempBond, Kerr to their dedicated abutments. A hole was made in the location of screw access channel in group 2 and 3 and filled with photo-polymerized composite resin (3M; ESPE. All specimens were thermocycled and loaded in universal testing machine at crosshead speed of 2mm/min until fracture. Mean values of load at fracture were calculated in each group and compared with One-way ANOVA (α=0.05. Results: Mean value of the load required to fracture the restorations was 1947±487 N in group 1, 1927±539 N in group 2, and 2170±738 N in group 3. No statistically significant difference was found between the fracture resistance values of the three groups (p> 0.05 Conclusion: Presence of screw access channel in cement-retained implant restora-tions does not compromise fracture resistance.

  4. Influence of Sealing of the Screw Access Hole on the Fracture Resistance of Implant-Supported Restorations.

    Science.gov (United States)

    Pereira, Rodrigo de Paula; Rocha, Cibele Oliveira de Melo; Reis, José Maurício dos Santos Nunes; Arioli-Filho, João Neudenir

    2016-01-01

    The purpose of this study was to assess the influence of sealing of the screw access hole (SAH) on the fracture resistance of metal-ceramic implant-supported restorations. UCLA abutments were used to make 30 implant-retained mandibular molar restorations and divide equally into three groups: Group SRS: screw-retained restorations with SAH sealed; Group SRNS: screw-retained restorations with SAH not sealed; Group CR: cement-retained restorations. The following protocol was adopted to restore the SAH: the ceramic surface of the SAH was air-abraded with aluminum oxide; etched with 10% hydrofluoric acid; a silane coupling agent and a bonding agent were applied; cotton pellets were used as filling material and P-60 resin composite as restoring material. The cement-retained restorations were cemented with Rely-X U100. A metal rod with a spherical tip of 6.0 mm diameter was used to apply a vertical static load, simultaneously on the buccal and lingual incline cusps, at a crosshead speed of 0.5 mm/min until the fracture of the specimens. Data were analyzed using one-way ANOVA and Dunnet test (p<0.05) for multiples comparisons. The mode of failure was evaluated by a scanning electron microscopy (SEM). No significant difference between screw-retained restorations was found. The highest mean fracture resistance values were observed with CR group. Therefore, it was shown that SAH sealing did not influence the fracture resistance of the screw-retained restorations. PMID:27058376

  5. Thermal-hydraulic analysis under partial loss of flow accident hypothesis of a plate-type fuel surrounded by two water channels using RELAP5 code

    Directory of Open Access Journals (Sweden)

    Itamar Iliuk

    2016-01-01

    Full Text Available Thermal-hydraulic analysis of plate-type fuel has great importance to the establishment of safety criteria, also to the licensing of the future nuclear reactor with the objective of propelling the Brazilian nuclear submarine. In this work, an analysis of a single plate-type fuel surrounding by two water channels was performed using the RELAP5 thermal-hydraulic code. To realize the simulations, a plate-type fuel with the meat of uranium dioxide sandwiched between two Zircaloy-4 plates was proposed. A partial loss of flow accident was simulated to show the behavior of the model under this type of accident. The results show that the critical heat flux was detected in the central region along the axial direction of the plate when the right water channel was blocked.

  6. Remote sensing and GIS-based integrated analysis of land cover change in Duzce plain and its surroundings (north western Turkey).

    Science.gov (United States)

    Ikiel, Cercis; Ustaoglu, Beyza; Dutucu, Ayse Atalay; Kilic, Derya Evrim

    2013-02-01

    The aim of this study is to research natural land cover change caused by the permanent effects of human activities in Duzce plain and its surroundings, and to determine the current status of the land cover. For this purpose, two Landsat TM images were used in the study for the years 1987 and 2010. These images are analysed by using data image processing techniques in ERDAS Imagine©10.0 and ArcGIS©10.0 software. Land cover change nomenclature is classified according to the Coordination of Information on the Environment Level 2 Classification (1--urban fabric, 2--industrial, commercial and transport units, 3--heterogeneous agricultural areas, 4--forests, and 5--inland wetlands). Furthermore, the image analysis results are confirmed by the field research. According to the results, a decrease of 33.5 % was recorded in forest areas from 24,840.7 to 16,529.0 ha; an increase of 11.2 % was recorded in heterogeneous agricultural areas from 47,702.7 to 53,051.7 ha. Natural vegetation, which is the large part of land cover in the research area, has been changing rapidly because of rapid urbanisation and agricultural activities. As a result, it is concluded that significant changes have occurred on the natural land cover between the years 1987 and 2010 in the Duzce plain and its surroundings.

  7. Numerical Stress Analysis of Surrounding Rocks of Adjacent Parallel Tunnels%相邻平行巷道围岩应力数值分析

    Institute of Scientific and Technical Information of China (English)

    王吉

    2015-01-01

    为了研究相邻平行巷道围岩应力分布,应用ANSYS有限元软件,模拟不同开采深度,不同岩柱宽度时的巷道围岩应力分布特点,通过分析拱顶、拱基、墙中、墙底这些关键点的水平及垂直应力,概括总结影响相邻巷道稳定性主要应力因素,为煤矿安全、经济生产提供参考。%In order to study the distribution of numerical stress of surrounding rocks ,with the ANSYS finite element software , simulates different mining depth ,different rock pillar width of the roadway surrounding rock stress distribution characteristics . Through the analysis of the arch ,chaptrel ,wall and the horizontal and vertical stress at the bottom of the key points ,this paper summarizes the main stress factors influencing adjacent tunnel stability ,provides a reference for coal mine safety and economic production .

  8. Effect of screw access hole preparation on fracture load of implant-supported zirconia-based crowns: an in vitro study

    Science.gov (United States)

    Mokhtarpour, Hadi; Eftekhar Ashtiani, Reza; Mahshid, Minoo; Tabatabaian, Farhad; Alikhasi, Marzieh

    2016-01-01

    Background. Fracture load of implant-supported restorations is an important factor in clinical success. This study evaluated the effect of two techniques for screw access hole preparation on the fracture load of cement-screw-retained implant-supported zirconia-based crowns. Methods. Thirty similar cement-screw-retained implant-supported zirconia-based maxillary central incisor crowns were evaluated in three groups of 10. Group NH: with no screw access holes for the control; Group HBS: with screw access holes prepared with a machine before zirconia sintering; Group HAS: with screw access holes prepared manually after zirconia sintering. In group HBS, the access holes were virtually designed and prepared by a computer-assisted design/computer-assisted manufacturing system. In group HAS, the access holes were manually prepared after zirconia sintering using a diamond bur. The dimensions of the screw access holes were equal in both groups. The crowns were cemented onto same-size abutments and were then subjected to thermocycling. The fracture load values of the crowns were measured using a universal testing machine. Data were analyzed with ANOVA and Tukey test (P zirconia-based crowns decreased the fracture load. PMID:27651885

  9. Comparing the Accuracy of Silicone and Polyether in Reproducing Gingival Height for Implant Supported Crown: an in vitro study

    Directory of Open Access Journals (Sweden)

    Derafshi R

    2015-03-01

    Full Text Available Statement of Problem: Accurate impressions are one of the most critical factors in achieving acceptable restorations. When pouring the impressions of implant supported restorations, soft materials like silicone and polyether are used to reconstruct the gingival form around the implants. To the best of our knowledge, no study has been conducted on the comparison of the accuracy of these soft materials. Objectives: To evaluate the accuracy of polyether and silicone in reproducing the correct depth of gingival sulcus around the implants by probing. Materials and Methods: By the use of a periodontal probe, the gingival height was measured in six marked areas of one maxillary partial edentullism model on which two fixture analogs were attached and three points were marked around each analog for measurements, which was considered as an index height. Addition silicone impression material (putty and wash was used to simultaneously take 10 impressions of the model. The samples were randomly divided into two groups of 5 and each impressions was poured twice; for the first group, the impressions were first poured with silicone, and for the second one they were poured with polyether material for reproducing the gingival contour; in the second group, the procedure was performed in reverse. Therefore, there were 10 casts in each group and because each cast contained two analogues, and each analogue was marked in three points for measuring gingival height, 60 numbers were achieved for each group as the gingival height. The mean gingival heights were compared by paired t-test using SPSS software, version 18 (p = 0.05. Results: Comparison of the mean gingival height of the silicone and control groups revealed that there was no significant difference between the two groups (p = 0.090, whereas, a significant difference was found between the mean gingival height of the polyether and control groups (p = 0.034. Conclusions: Within the limitation of this study, it was

  10. A feasible, aesthetic quality evaluation of implant-supported single crowns: an analysis of validity and reliability

    DEFF Research Database (Denmark)

    Hosseini, Mandana; Gotfredsen, Klaus

    2012-01-01

    and the internal consistency were analysed by Cohen's ¿ and Cronbach's a, respectively. The validity of CIS parameters was tested against the corresponding Visual Analogue Scales (VAS) scores. The Spearman correlation coefficients were used. Six aesthetic Oral Health Impact Profile (OHIP) questions were correlated....... The crown morphology and the symmetry/harmony scores had the overall lowest agreement. The Cronbach a value was over 0.8 for all observers. All CIS scores demonstrated significant (P-0...

  11. The influence of interproximal contact on implant-supported fixed partial dentures in the posterior jaw: a photoelastic analysis.

    Science.gov (United States)

    Naves, Marina Melo; de Menezes, Helder Henrique Machado; de Magalhães, Denildo; de Araújo, Cleudmar Amaral; Júnior, Paulo Cézar Simamoto

    2015-02-01

    The aim of this study was to analyze the effect of the separation of prosthetic crowns from fixed partial dentures by means of stress gradient evaluation. Three photoelastic models were created to examine contiguous implants with varying contact between the crowns (contact point [CP], contact surface [CS], splinted [SP]). The SP group presented the best results, followed by the CS group, indicating that the use of splinted prosthetic crowns and crowns with broad surface contacts is viable when considering the stress values. PMID:23397888

  12. Primerjava zadovoljstva bolnikov po oskrbi s spodnjo totalno protezo brez in z zobnimi vsadki: Satisfaction of patients treated with implant-supported mandibular overdenture compared to patients treated with conventional denture:

    OpenAIRE

    Ihan Hren, Nataša; Gačnik, Jure

    2011-01-01

    Backgrounds. Treatment of total edentulism with implant-supported overdenture is an established alternative to the conventional removable denture, especially in the case of poor anatomical conditions in the mandible. The aim of our study was to estimate the difference in satisfaction based on the quality oflife aspect in totally edentulous Slovenian patients treated with mandibular implant-supported overdentures or conventional removable dentures by using a standardized questionnaire. Methods...

  13. An in vitro investigation into retention strength and fatigue resistance of various designs of tooth/implant supported overdentures.

    Science.gov (United States)

    Fatalla, Abdalbseet A; Song, Ke; Du, Tianfeng; Cao, Yingguang

    2012-02-01

    and 2880 insertion and removal cycles. During the tensile test a cross-head speed of 10 mm/min was applied. Values of absolute force (AF) and relative force (RF) were statistically analyzed by two-way ANOVA and multiple comparison Tukey's tests between groups and cycles periods. The results of fatigue tests showed a 50% reduction in retention force in the subgroups with flexible attachments. A triangular design of overdenture support foundations with O-Ring attachments revealed the lowest value of AF and a relatively high reduction in RF. The four overdenture support designs with flexible acrylic attachments improved the retention force and reduced the fatigue retention. Furthermore, the results of the investigation demonstrate that flexible acrylic attachments for both teeth and implant-supported overdentures offer a wide range of retention forces. PMID:22282258

  14. Theory Analysis and Engineering Application of Tunnel Surrounding Rock Grouting%隧道围岩注浆的理论分析及工程应用

    Institute of Scientific and Technical Information of China (English)

    朱红; 杜嘉鸿

    2012-01-01

    目的 为解决铁道工程、水利工程和煤矿建设中的隧道、隧洞和斜井等顺利通过滑坡地区、软土地区等地质条件复杂情况的问题.方法 根据掘进距离长、埋深浅、环境保护要求高等特点,采用注浆技术对隧道周围土体进行加固,并对高喷注浆的机理进行分析,建立隧道与周围土体的力学模型,选取相应的特征参数进行力学分析.结果 给出了作用在注浆加固体上压力的计算公式,并将成果应用于工程实践,加快了工程进度,减少了工程成本,取得了良好的加固效果.结论 采用高喷注浆治理滑坡、软土层中矿山斜井和水利涵洞周围土体是有效的加固途径,工程实践证明笔者提出力学模型和分析方法是可行的.%This paper is aimed to study complex circumstance in railway engineering, hydraulic engineering and construction of coal mines, tunnels and shafts and tunnels can smoothly through the landslide area, soft soil geological condition. According to these projects with the long driving distance, shallow buried depth, high environmental protection requirements, using grouting technology for tunnel surrounding soil reinforcement due to the high pressure Jet grouting mechanism is analyzed. Mechanical model of soil around tunnel is established,and the corresponding characteristic parameters used in mechanical analysis are selected. Calculation formula of solid pressure,are derived which can be used in engineering practice,and achieved good reinforcement effect,speed up the progress of the project,and reduce the cost of the project. Using high pressure jet grouting in soft soil, landslide control in mine inclined shaft and water conservancy culvert surrounding soil are effective reinforcement approach, the mechanical model and the analysis method of this paper are feasible.

  15. The Evolution and Fabrication of Implant-supported Full-arch Hybrid Prostheses. From Conventional Casted Metal to an All-Ceramic Zirconia.

    Science.gov (United States)

    Ouzer, Amanda

    2015-11-01

    Implant-supported, full-arch hybrid prostheses have developed from cast-metal frameworks with acrylic or porcelain to all-ceramic zirconia frameworks. CAD/CAM manufacturing removed the inaccuracies seen with casting and made use of zirconia possible. The materials and processes for prosthodontic fabrication are explained. Zirconia is highly opaque and versatile. However, porcelain-veneered zirconia frameworks have shown higher enamel wear, among other problems. Lithium disilicate has been shown to be more translucent than zirconia. Improved stained and more translucent zirconia frameworks have been produced as well. These promising new methods have gained popularity, but long-term studies are scarce and, thus, more research is required.

  16. Microarray analysis of gene expression after electrical stimulation of the dura mater surrounding the superior sagittal sinus in conscious adult rats

    Institute of Scientific and Technical Information of China (English)

    Jiang Lei; Dong Zhao; Li Fengpeng; Liu Ruozhuo; Qiu Enchao; Wang Xiaolin; Yu Shengyuan

    2014-01-01

    Background The molecular and cellular origins of migraine headache are among the most complex problems in contemporary neurology.Up to now the pathogenesis of migraine still remains unclearly defined.The objective of this study was to explore new factors that may be related to the mechanism of migraine.Methods The present study performed a comprehensive analysis of gene expression in the trigeminal nucleus caudalis induced by electrical stimulation of dura mater surrounding the superior sagittal sinus in conscious rats using microarray analysis followed by quantitative real-time reverse-transcribed polymerase chain reaction (qRT-PCR) verification.Student's two sample t-test was employed when two groups were compared.A P value <0.05 was considered to be statistically significant.Results Comparing the placebo and the electrical stimulation groups,40 genes were determined to be significantly differentially expressed.These significantly differentially expressed genes were involved in many pathways,including transporter activity,tryptophan metabolism,G protein signaling,kinase activity,actin binding,signal transducer activity,anion transport,protein folding,enzyme inhibitor activity,coenzyme metabolism,binding,ion transport,cell adhesion,metal ion transport,oxidoreductase activity,mitochondrion function,and others.Most of the genes were involved in more than 2 pathways.Of particular interest is the up-regulation of Phactr3 and Akap5 and the down-regulation of Kdr.Conclusion These findings may provide important clues for a better understanding of the molecular mechanism of migraine.

  17. Electromembrane Surrounded Solid Phase Microextraction Followed by Injection Port Derivatization and Gas Chromatography-Flame Ionization Detector Analysis for Determination of Acidic Herbicides in Plant Tissue.

    Science.gov (United States)

    Rezazadeh, Maryam; Yamini, Yadollah; Seidi, Shahram; Tahmasebi, Elham; Rezaei, Fatemeh

    2014-04-01

    Electromembrane surrounded solid phase microextraction (EM-SPME) of acidic herbicides was studied for the first time. In order to investigate the capability of this new microextraction technique to analyze acidic targets, chlorophenoxy acid (CPA) herbicides were quantified in plant tissue. 1-Octanol, was sustained in the pores of the wall of a hollow fiber and served as supported liquid membrane (SLM). Other EM-SPME related parameters, including extraction time, applied voltage, and pHs of the sample solution and the acceptor phase, were optimized using experimental design. A 20 min time frame was needed to reach the highest extraction efficiency of the analytes from a 24 mL alkaline sample solution across the organic liquid membrane and into the aqueous acceptor phase through a 50 V electrical field, and to their final adsorption on a carbonaceous anode. In addition to high sample cleanup, which made the proposed method appropriate for analysis of acidic compounds in a complicated media (plant tissue), 4.8% of 2-methyl-4-chlorophenoxyacetic acid (MCPA) and 0.6% of 2,4-dichlorophenoxyacetic acid (2,4-D) were adsorbed on the anode, resulting in suitable detection limits (less than 5 ng mL(-1)), and admissible repeatability and reproducibility (intra- and interassay precision were in the ranges of 5.2-8.5% and 8.8-12.0%, respectively). Linearity of the method was scrutinized within the ranges of 1.0-500.0 and 10.0-500.0 ng mL(-1) for MCPA and 2,4-D, respectively, and coefficients of determination greater than 0.9958 were obtained. Optimal conditions of EM-SPME of the herbicides were employed for analysis of CPAs in whole wheat tissue. PMID:24660667

  18. Effects of Mucosal Thickness on the Stress Distribution and Denture Stability of Mandibular Implant-Supported Overdentures with Unsplinted Attachments In Vitro

    Science.gov (United States)

    Haruta, Asuka; Matsushita, Yasuyuki; Tsukiyama, Yoshihiro; Sawae, Yoshinori; Sakai, Nobuo; Koyano, Kiyoshi

    2011-01-01

    The aim of this study was to compare the effects of mucosal thickness on the stress pattern around implants and movement of implant-supported overdentures with ball/female and three different types of magnetic attachments. After insertion of two root-form implants into a mandibular model, the surface of the model was covered with a 1.5- or 3-mm layer of impression material to simulate the oral mucosa, and removable overdentures were fabricated on each model. A 50-N vertical force was applied to the right first molar, and the resultant stress distribution and denture movement were measured. In the 1.5-mm mucosal model, the magnetic attachments showed significantly lower bending moments than did the ball attachment. The denture base displacement was the lowest on a magnetic attachment. In this study, use of magnetic attachments could be advantageous for mandibular implant-supported overdentures based on lower stress and better denture stability especially in the thin mucosal model. PMID:21799705

  19. Effect of cantilever length and alloy framework on the stress distribution in peri-implant area of cantilevered implant-supported fixed partial dentures.

    Science.gov (United States)

    Suedam, Valdey; Moretti Neto, Rafael Tobias; Sousa, Edson Antonio Capello; Rubo, José Henrique

    2016-04-01

    Because many mechanical variables are present in the oral cavity, the proper load transfer between the prosthesis and the bone is important for treatment planning and for the longevity of the implant-supported fixed partial denture. Objectives To verify the stress generated on the peri-implant area of cantilevered implant-supported fixed partial dentures and the potential effects of such variable. Material and Methods A U-shaped polyurethane model simulating the mandibular bone containing two implants (Ø 3.75 mm) was used. Six groups were formed according to the alloy's framework (CoCr or PdAg) and the point of load application (5 mm, 10 mm and 15 mm of cantilever arm). A 300 N load was applied in pre-determined reference points. The tension generated on the mesial, lingual, distal and buccal sides of the peri-implant regions was assessed using strain gauges. Results Two-way ANOVA and Tukey statistical tests were applied showing significant differences (p<0.05) between the groups. Pearson correlation test (p<0.05) was applied showing positive correlations between the increase of the cantilever arm and the deformation of the peri-implant area. Conclusions This report demonstrated the CoCr alloy shows larger compression values compared to the PdAg alloy for the same distances of cantilever. The point of load application influences the deformation on the peri-implant area, increasing in accordance with the increase of the lever arm. PMID:27119758

  20. Vertical misfit of laser-sintered and vacuum-cast implant-supported crown copings luted with definitive and temporary luting agents

    Science.gov (United States)

    Sánchez-Turrión, Andrés; López-Lozano, José F.; Albaladejo, Alberto; Torres-Lagares, Daniel; Montero, Javier; Suárez-García, Maria J.

    2012-01-01

    Objectives. This study aimed to evaluate the vertical discrepancy of implant-supported crown structures constructed with vacuum-casting and Direct Metal Laser Sintering (DMLS) technologies, and luted with different cement types. Study Design. Crown copings were fabricated using: (1) direct metal laser sintered Co-Cr (LS); (2) vacuum-cast Co-Cr (CC); and (3) vacuum-cast Ti (CT). Frameworks were luted onto machined implant abutments under constant seating pressure. Each alloy group was randomly divided into 5 subgroups (n = 10 each) according to the cement system utilized: Subgroup 1 (KC) used resin-modified glass-ionomer Ketac Cem Plus; Subgroup 2 (PF) used Panavia F 2.0 dual-cure resin cement; Subgroup 3 (RXU) used RelyX Unicem 2 Automix self-adhesive dual-cure resin cement; Subgroup 4 (PIC) used acrylic/urethane-based temporary Premier Implant Cement; and Subgroup 5 (DT) used acrylic/urethane-based temporary DentoTemp cement. Vertical misfit was measured by scanning electron microscopy (SEM). Two-way ANOVA and Student-Newman-Keuls tests were run to investigate the effect of alloy/fabrication technique, and cement type on vertical misfit. The statistical significance was set at α = 0.05. Results. The alloy/manufacturing technique and the luting cement affected the vertical discrepancy (p < 0.001). For each cement type, LS samples exhibited the best fit (p < 0.01) whereas CC and CT frames were statistically similar. Within each alloy group, PF and RXU provided comparably greater discrepancies than KC, PIC, and DT, which showed no differences. Conclusions. Laser sintering may be an alternative to vacuum-casting of base metals to obtain passive-fitting implant-supported crown copings. The best marginal adaptation corresponded to laser sintered structures luted with glass-ionomer KC, or temporary PIC or DT cements. The highest discrepancies were recorded for Co-Cr and Ti cast frameworks bonded with PF or RXU resinous agents. All groups were within the clinically

  1. The Evolution and Fabrication of Implant-supported Full-arch Hybrid Prostheses. From Conventional Casted Metal to an All-Ceramic Zirconia.

    Science.gov (United States)

    Ouzer, Amanda

    2015-11-01

    Implant-supported, full-arch hybrid prostheses have developed from cast-metal frameworks with acrylic or porcelain to all-ceramic zirconia frameworks. CAD/CAM manufacturing removed the inaccuracies seen with casting and made use of zirconia possible. The materials and processes for prosthodontic fabrication are explained. Zirconia is highly opaque and versatile. However, porcelain-veneered zirconia frameworks have shown higher enamel wear, among other problems. Lithium disilicate has been shown to be more translucent than zirconia. Improved stained and more translucent zirconia frameworks have been produced as well. These promising new methods have gained popularity, but long-term studies are scarce and, thus, more research is required. PMID:26749784

  2. Fabricating a tooth- and implant-supported maxillary obturator for a patient after maxillectomy with computer-guided surgery and CAD/CAM technology: A clinical report.

    Science.gov (United States)

    Noh, Kwantae; Pae, Ahran; Lee, Jung-Woo; Kwon, Yong-Dae

    2016-05-01

    An obturator prosthesis with insufficient retention and support may be improved with implant placement. However, implant surgery in patients after maxillary tumor resection can be complicated because of limited visibility and anatomic complexity. Therefore, computer-guided surgery can be advantageous even for experienced surgeons. In this clinical report, the use of computer-guided surgery is described for implant placement using a bone-supported surgical template for a patient with maxillary defects. The prosthetic procedure was facilitated and simplified by using computer-aided design/computer-aided manufacture (CAD/CAM) technology. Oral function and phonetics were restored using a tooth- and implant-supported obturator prosthesis. No clinical symptoms and no radiographic signs of significant bone loss around the implants were found at a 3-year follow-up. The treatment approach presented here can be a viable option for patients with insufficient remaining zygomatic bone after a hemimaxillectomy. PMID:26774316

  3. Effect of cantilever length and alloy framework on the stress distribution in peri-implant area of cantilevered implant-supported fixed partial dentures

    Science.gov (United States)

    SUEDAM, Valdey; MORETTI, Rafael Tobias; SOUSA, Edson Antonio Capello; RUBO, José Henrique

    2016-01-01

    ABSTRACT Because many mechanical variables are present in the oral cavity, the proper load transfer between the prosthesis and the bone is important for treatment planning and for the longevity of the implant-supported fixed partial denture. Objectives To verify the stress generated on the peri-implant area of cantilevered implant-supported fixed partial dentures and the potential effects of such variable. Material and Methods A U-shaped polyurethane model simulating the mandibular bone containing two implants (Ø 3.75 mm) was used. Six groups were formed according to the alloy’s framework (CoCr or PdAg) and the point of load application (5 mm, 10 mm and 15 mm of cantilever arm). A 300 N load was applied in pre-determined reference points. The tension generated on the mesial, lingual, distal and buccal sides of the peri-implant regions was assessed using strain gauges. Results Two-way ANOVA and Tukey statistical tests were applied showing significant differences (p<0.05) between the groups. Pearson correlation test (p<0.05) was applied showing positive correlations between the increase of the cantilever arm and the deformation of the peri-implant area. Conclusions This report demonstrated the CoCr alloy shows larger compression values compared to the PdAg alloy for the same distances of cantilever. The point of load application influences the deformation on the peri-implant area, increasing in accordance with the increase of the lever arm. PMID:27119758

  4. Effect of cantilever length and alloy framework on the stress distribution in peri-implant area of cantilevered implant-supported fixed partial dentures

    Directory of Open Access Journals (Sweden)

    Valdey SUEDAM

    2016-04-01

    Full Text Available ABSTRACT Because many mechanical variables are present in the oral cavity, the proper load transfer between the prosthesis and the bone is important for treatment planning and for the longevity of the implant-supported fixed partial denture. Objectives To verify the stress generated on the peri-implant area of cantilevered implant-supported fixed partial dentures and the potential effects of such variable. Material and Methods A U-shaped polyurethane model simulating the mandibular bone containing two implants (Ø 3.75 mm was used. Six groups were formed according to the alloy’s framework (CoCr or PdAg and the point of load application (5 mm, 10 mm and 15 mm of cantilever arm. A 300 N load was applied in pre-determined reference points. The tension generated on the mesial, lingual, distal and buccal sides of the peri-implant regions was assessed using strain gauges. Results Two-way ANOVA and Tukey statistical tests were applied showing significant differences (p<0.05 between the groups. Pearson correlation test (p<0.05 was applied showing positive correlations between the increase of the cantilever arm and the deformation of the peri-implant area. Conclusions This report demonstrated the CoCr alloy shows larger compression values compared to the PdAg alloy for the same distances of cantilever. The point of load application influences the deformation on the peri-implant area, increasing in accordance with the increase of the lever arm.

  5. Effect of proximal contact strength on the three-dimensional displacements of implant-supported cantilever fixed partial dentures under axial loading

    Institute of Scientific and Technical Information of China (English)

    Zhen-zhen PENG; Xin-min CHEN; Jun WANG; Ai-jie LI; Zu-jie XU

    2013-01-01

    Objective:This study investigated the effect of proximal contact strength on the three-dimensional displacements of cantilever fixed partial denture (CFPD) under vertically concentrated loading with digital laser speckle (DLS) technique.Methods:Fresh mandible of beagle dog was used to establish the implant-supported CFPD for specimen.DLS technique was employed for measuring the three-dimensional displacement of the prosthesis under vertically concentrated loading ranging from 200 to 3000 g.The effect of the contact tightness on the displacement of CFPD was investigated by means of changing the contact tightness.Results:When an axial concentrated loading was exerted on the pontic of the implant-supported CFPD,the displacement of the CFPD was the greatest.The displacement of the prosthesis decreased with the increase of contact strength.When the contact strength was 0,0.95,and 3.25 N,the displacement of the buccolingual direction was smaller than that of the mesiodistal direction but greater than that of the occlusogingival direction.When the force on the contact area was 6.50 N,the mesiodistal displacement of the prosthesis was the biggest while the buccolingual displacement was the smallest.Conclusions:The implantsupported CFPD is an effective therapy for fully or partially edentulous patients.The restoration of the contact area and the selection of the appropriate contact strength can reduce the displacement of the CFPD,and get a better stress distribution.The most appropriate force value is 3.25 N in this study.

  6. Surface shapes and surrounding environment analysis of single- and double-stranded DNA-binding proteins in protein-DNA interface.

    Science.gov (United States)

    Wang, Wei; Liu, Juan; Sun, Lin

    2016-07-01

    Protein-DNA bindings are critical to many biological processes. However, the structural mechanisms underlying these interactions are not fully understood. Here, we analyzed the residues shape (peak, flat, or valley) and the surrounding environment of double-stranded DNA-binding proteins (DSBs) and single-stranded DNA-binding proteins (SSBs) in protein-DNA interfaces. In the results, we found that the interface shapes, hydrogen bonds, and the surrounding environment present significant differences between the two kinds of proteins. Built on the investigation results, we constructed a random forest (RF) classifier to distinguish DSBs and SSBs with satisfying performance. In conclusion, we present a novel methodology to characterize protein interfaces, which will deepen our understanding of the specificity of proteins binding to ssDNA (single-stranded DNA) or dsDNA (double-stranded DNA). Proteins 2016; 84:979-989. © 2016 Wiley Periodicals, Inc.

  7. Local surrounding of vanadium atoms in CuCr1 - x V x S2: X-ray absorption spectroscopy analysis

    Science.gov (United States)

    Smirnova, Yu. O.; Smolentsev, N. Yu.; Guda, A. A.; Soldatov, M. A.; Kvashnina, K. O.; Glatzel, P.; Korotaev, E. V.; Soldatov, A. V.; Mazalov, L. N.

    2013-03-01

    In the present work local surrounding of vanadium atoms in layered copper-chromium disulfides CuCr1 - x V x S2 is investigated using high-resolution X-ray absorption spectroscopy above vanadium K-edge. Based on experimental and theoretically simulated spectra comparison it is shown that vanadium atoms replace chromium ones even at high concentrations of vanadium and that they are in 3+ oxidation state.

  8. Reduced surround inhibition in musicians.

    Science.gov (United States)

    Shin, Hae-Won; Kang, Suk Y; Hallett, Mark; Sohn, Young H

    2012-06-01

    To investigate whether surround inhibition (SI) in the motor system is altered in professional musicians, we performed a transcranial magnetic stimulation (TMS) study in 10 professional musicians and 15 age-matched healthy non-musicians. TMS was set to be triggered by self-initiated flexion of the index finger at different intervals ranging from 3 to 1,000 ms. Average motor evoked potential (MEP) amplitudes obtained from self-triggered TMS were normalized to average MEPs of the control TMS at rest and expressed as a percentage. Normalized MEP amplitudes of the abductor digiti minimi (ADM) muscles were compared between the musicians and non-musicians with the primary analysis being the intervals between 3 and 80 ms (during the movement). A mixed-design ANOVA revealed a significant difference in normalized ADM MEPs during the index finger flexion between groups, with less SI in the musicians. This study demonstrated that the functional operation of SI is less strong in musicians than non-musicians, perhaps due to practice of movement synergies involving both muscles. Reduced SI, however, could lead susceptible musicians to be prone to develop task-specific dystonia.

  9. Visual surround suppression in schizophrenia

    Directory of Open Access Journals (Sweden)

    Marc Samuel Tibber

    2013-02-01

    Full Text Available Compared to unaffected observers patients with schizophrenia show characteristic differences in visual perception, including a reduced susceptibility to the influence of context on judgements of contrast - a manifestation of weaker surround suppression. To examine the generality of this phenomenon we measured the ability of 24 individuals with schizophrenia to judge the luminance, contrast, orientation and size of targets embedded in contextual surrounds that would typically influence the target’s appearance. Individuals with schizophrenia demonstrated weaker surround suppression compared to matched controls for stimuli defined by contrast or size, but not for those defined by luminance or orientation. As perceived luminance is thought to be regulated at the earliest stages of visual processing our findings are consistent with a suppression deficit that is predominantly cortical in origin. In addition, we propose that preserved orientation surround suppression in schizophrenia may reflect the sparing of broadly tuned mechanisms of suppression. We attempt to reconcile these data with findings from previous studies.

  10. Educational Success and Surrounding Culture

    Science.gov (United States)

    Walters, Garrison

    2016-01-01

    The curriculum, instruction, and services we provide in schools, colleges, and universities matter a lot, but if we continue to ignore our students' "surrounding culture," progress toward a more educated nation will continue to be disappointing.

  11. Visual Surround Suppression in Schizophrenia

    OpenAIRE

    Tibber, Marc S.; Elaine J Anderson; Bobin, Tracy; Antonova, Elena; Seabright, Alice; Wright, Bernice; Carlin, Patricia; Shergill, Sukhwinder S.; Dakin, Steven C.

    2013-01-01

    Compared to unaffected observers patients with schizophrenia (SZ) show characteristic differences in visual perception, including a reduced susceptibility to the influence of context on judgments of contrast – a manifestation of weaker surround suppression (SS). To examine the generality of this phenomenon we measured the ability of 24 individuals with SZ to judge the luminance, contrast, orientation, and size of targets embedded in contextual surrounds that would typically influence the targ...

  12. Visual surround suppression in schizophrenia

    OpenAIRE

    Marc Samuel Tibber; Elaine J Anderson; Tracy eBobin; Elena eAntonova; Alice eSeabright; Bernice eWright; Patricia eCarlin; Shergill, Sukhwinder S.; Dakin, Steven C.

    2013-01-01

    Compared to unaffected observers patients with schizophrenia show characteristic differences in visual perception, including a reduced susceptibility to the influence of context on judgements of contrast - a manifestation of weaker surround suppression. To examine the generality of this phenomenon we measured the ability of 24 individuals with schizophrenia to judge the luminance, contrast, orientation and size of targets embedded in contextual surrounds that would typically influence the tar...

  13. Parameters of passive fit using a new technique to mill implant-supported superstructures: an in vitro study of a novel three-dimensional force measurement-misfit method

    NARCIS (Netherlands)

    A. Tahmaseb; J.J. van de Weijden; P. Mercelis; R. de Clerck; D. Wismeijer

    2010-01-01

    Purpose: The objectives of this study are to describe, in vitro, a novel technique to measure the misfit of digitally designed and manufactured implant-supported frameworks according to a new concept based on computer-guided surgery in combination with previously placed mini-implants. Also, the digi

  14. Zonal disintegration phenomenon in enclosing rock mass surrounding deep tunnels Elasto-plastic analysis of stress field of enclosing rock mass

    Institute of Scientific and Technical Information of China (English)

    WU Hao; FANG Qin; ZHANG Ya-dong; GONG Zi-ming

    2009-01-01

    The zonal disintegration phenomenon (ZDP) is a typical phenomenon in deep block rock masses. In order to investigate the mechanism of ZDP, an improved non-linear Hock-Brown strength criterion and a bi-linear constitutive model of rock mass were used to analyze the elasto-plastic stress field of the enclosing rock mass around a deep round tunnel. The radius of the plastic region and stress of the enclosing rock mass were obtained by introducing dimensionless parameters of radial distance. The results show that tunneling in deep rock mass causes a maximum stress zone to appear in the vicinity of the boundary of the elastic and the plas-tic zone in the surrounding rock mass. Under the compression of a large tangential force and a small radial force, the rock mass in the maximum stress zone was in an approximate uniaxial loading state, which could lead to a split failure in the rock mass.

  15. Nonlinear dynamic analysis of eccentrically stiffened functionally graded circular cylindrical thin shells under external pressure and surrounded by an elastic medium

    International Nuclear Information System (INIS)

    A semi-analytical approach eccentrically stiffened functionally graded circular cylindrical shells surrounded by an elastic medium subjected to external pressure is presented. The elastic medium is assumed as two-parameter elastic foundation model proposed by Pasternak. Based on the classical thin shell theory with the geometrical nonlinearity in von Karman-Donnell sense, the smeared stiffeners technique and Galerkin method, this paper deals the nonlinear dynamic problem. The approximate three-term solution of deflection shape is chosen and the frequency-amplitude relation of nonlinear vibration is obtained in explicit form. The nonlinear dynamic responses are analyzed by using fourth order Runge-Kutta method and the nonlinear dynamic buckling behavior of stiffened functionally graded shells is investigated according to Budiansky-Roth criterion. Results are given to evaluate effects of stiffener, elastic foundation and input factors on the frequency-amplitude curves, natural frequencies, nonlinear responses and nonlinear dynamic buckling loads of functionally graded cylindrical shells. (authors)

  16. A convection-conduction model for analysis of the freeze-thaw conditions in the surrounding rock wall of a tunnel in permafrost regions

    Institute of Scientific and Technical Information of China (English)

    何春雄; 吴紫汪; 朱林楠

    1999-01-01

    Based on the analyses of fundamental meteorological and hydrogeological conditions at the site of a tunnel in the cold regions, a combined convection-conduction model for air flow in the tunnel and temperature field in the surrounding has been constructed. Using the model, the air temperature distribution in the Xiluoqi No. 2 Tunnel has been simulated numerically. The simulated results are in agreement with the data observed. Then, based on the in situ conditions of air temperature, atmospheric pressure, wind force, hydrogeology and engineering geology, the air-temperature relationship between the temperature on the surface of the tunnel wall and the air temperature at the entry and exit of the tunnel has been obtained, and the freeze-thaw conditions at the Dabanshan Tunnel which is now under construction is predicted.

  17. Full Contoured Tooth-Implant Supported 3-Pointic All-Ceramic Denture During Occlusal Load Transfer in Lateral Region

    Directory of Open Access Journals (Sweden)

    Żmudzki J.

    2016-06-01

    Full Text Available Implant and a tooth supported dentures are avoided by dentists because of uneven distribution of occlusal loads between a stiffer implant and a more pliable tooth. The hypothesis was that a 3-point all-ceramic bridge supported on a natural second premolar tooth and a two-pieces typical implant bears safely mastication loads. The finite element analysis showed that the implant splinted by all-ceramic zirconium bridge with the second premolar was safe under lateral mastication load, but there was found an overload at wide zone of bone tissue around the implant under the load of 800 N. The patients can safely masticate, but comminution of hard food should be avoided and they should be instructed that after such an indiscretion they need to contact a dental professional, because, in spite of integrity of the prosthesis, the bone tissue around the implant may fail and there is a hazard of intrusion of the tooth.

  18. Influence of different catilever extensions and glass or polyamaramid reinforcement fibers on fracture strength of implant-supported temporary

    Directory of Open Access Journals (Sweden)

    Paola Colán Guzmán

    2008-04-01

    Full Text Available In long-term oral rehabilitation treatments, resistance of provisional crowns is a very important factor, especially in cases of an extensive edentulous distal space. The aim of this laboratorial study was to evaluate an acrylic resin cantilever-type prosthesis regarding the flexural strength of its in-balance portion as a function of its extension variation and reinforcement by two types of fibers (glass and polyaramid, considering that literature is not conclusive on this subject. Each specimen was composed by 3 total crowns at its mesial portion, each one attached to an implant component (abutment, while the distal portion (cantilever had two crowns. Each specimen was constructed by injecting acrylic resin into a two-part silicone matrix placed on a metallic base. In each specimen, the crowns were fabricated with either acrylic resin (control group or acrylic resin reinforced by glass (Fibrante, Angelus or polyaramide (Kevlar 49, Du Pont fibers. Compression load was applied on the cantilever, in a point located 7, 14 or 21 mm from the distal surface of the nearest crown with abutment, to simulate different extensions. The specimen was fixed on the metallic base and the force was applied until fracture in a universal test machine. Each one of the 9 sub-groups was composed by 10 specimens. Flexural strength means (in kgf for the distances of 7, 14 and 21 mm were, respectively, 28.07, 8.27 and 6.39 for control group, 31.89, 9.18 and 5.16 for Kevlar 49 and 30.90, 9.31 and 6.86 for Fibrante. Data analysis ANOVA showed statistically significant difference (p<0.05 only regarding cantilever extension. Tukey's test detected significantly higher flexural strength for the 7 mm-distance, followed by 14 and 21 mm. Fracture was complete only on specimens of non-reinforced groups.

  19. Update on Treated Tooth-Implant Supported Fixed Prosthesis%天然牙与种植体联合固定修复的研究进展

    Institute of Scientific and Technical Information of China (English)

    唐天弘(综述); 宋萌(审校)

    2015-01-01

    The aging of the population in Kennedy Ⅰ class and Ⅱ dentition defect rate is higher than before, with the increasing trend of pulp disease in the remaining teeth. New model that treated tooth-implatnt supported fixed prosthesis not only has a fixed partial denture comfort, but also more economical than implant denture. Aiming at the root canal treatment of tooth-implant supported fixed prosthesis, the article combine fixed restoration mechanism, the effect of treat-ment and common problems.%老龄人口肯氏I类和II类牙列缺损比率较高,且余留牙的牙体牙髓疾病多发。新型的根充后天然牙种植体联合固定修复不仅拥有固定义齿的舒适度,同时也比纯种植体支持式义齿更加经济。本文针对经根管治疗的天然牙-种植体联合固定修复这一方式的作用机制、治疗效果、常见问题等作一综述。

  20. 地下水封储油库围岩稳定性数值分析%Numerical analysis on the stability of surrounding rock for underground water-sealing oil storage in rock caverns

    Institute of Scientific and Technical Information of China (English)

    胡谋鹏; 粱久正; 许杰

    2013-01-01

    An underground water-sealing oil storage in rock caverns in Liaoning Province follows a low level of ground stress in the low-stress area. After its excavation, surrounding rock deformation and fracture are controlled under the combination between single structure plane and multi-group structure plane. Therefore, it is required to first analyze whether the surrounding rock suffer stress problems or structure plane problems and equivalent to value selection of surrounding rock parameters on the importance. Geological strength index (GSI) proposed by Hoek and Brown are based on rock quality evaluation. It can reduce subjectivity in determining the shear strength indicator to define rock mass mechanics parameters by the empirical formula. The underground water-sealed oil storage in rock caverns in Liaoning Province is taken as the object of study. Using the surrounding rock parameter value selection method based on GSI system as well as FLAC3D software, numerical analysis on the surrounding rock stability is conducted and its results are interpreted based on displacement criteria and stress criterion to determine the surrounding rock stability, thus having a guiding significance in engineering practice.%辽宁某地下水封储油硐库地应力水平不高,属于低应力区,开挖后围岩变形破坏受单一结构面和多组结构面的组合控制,因此首先需要分析围岩属于应力型问题还是属于结构面型问题,其重要性等同于围岩参数取值的重要性.Hoek和Brown提出的地质强度指标(GSI)法基于岩体质量评价,应用经验公式确定岩体力学参数,可以一定程度上减少确定抗剪强度指标过程中的主观成分.以辽宁某地下水封储油库工程储油硐室为研究对象,采用基于GSI系统的围岩参数取值方法,借助FLAC3D软件对围岩稳定性进行数值分析,利用位移判据和应力判据对数值分析结果进行解释,进而判断围岩的稳定性,对工程实践具有一定的指导意义.

  1. Implant-supported auricular prosthesis

    Directory of Open Access Journals (Sweden)

    Aditi Nanda

    2011-01-01

    Full Text Available Differences in the balance of shape, size, and position of body organs are immediately perceived as "looking wrong" and this perception can subject the individual to significant peer ridicule and social ostracism, often expressing as intense shame and anguish in the attitude of the afflicted. Rehabilitation of such patients can be remarkably beneficial on the individual′s self-esteem and body image. The onus of the deed lies in the hands of a team that combines artistic excellence with surgical expertise, by combining the skills of anaplastologists, surgeons, and prosthodontists. This is a review of a few surgical and prosthetic considerations in the management of auricular defect and a case description of management of a patient of microtia following similar guidelines in fabrication of the epithesis.

  2. Implant-supported auricular prosthesis

    OpenAIRE

    Aditi Nanda; Veena Jain; Rakesh Kumar; Krishna Kabra

    2011-01-01

    Differences in the balance of shape, size, and position of body organs are immediately perceived as "looking wrong" and this perception can subject the individual to significant peer ridicule and social ostracism, often expressing as intense shame and anguish in the attitude of the afflicted. Rehabilitation of such patients can be remarkably beneficial on the individual′s self-esteem and body image. The onus of the deed lies in the hands of a team that combines artistic excellence with surgic...

  3. [Myths and beliefs surrounding breastfeeding].

    Science.gov (United States)

    Marques, Emanuele Souza; Cotta, Rosângela Minardi Mitre; Priore, Silvia Eloiza

    2011-05-01

    The scope of this work was to analyze the main myths and beliefs surrounding breastfeeding for the theoretical-practical perspective of the various studies extant in the literature. The studies were obtained by bibliographical surveys in the main databases (Medline, Lilacs, scielo), retrieved using the key words "Breastfeeding," "Weaning," "Myths" and "Beliefs" (and their versions in English and Spanish). Books, theories, dissertations and publications in international and national organs were also consulted. It was seen that over the centuries there have been doubts surrounding the correct form of suckling newborns based on concepts that include biological aspects and socio-cultural determinants. It was seen that various myths and beliefs surrounding suckling generate either feelings of guilt, anxiety, or feelings of trust and support in the breastfeeding mother with respect to her capacity to produce breast milk. In this respect, it is necessary for healthcare professionals to understand suckling from the maternal standpoint, dispelling myths and beliefs, altering outlooks, in such a way as to comprehend the various factors present in suckling, acting in a more effective way for prolongation and maintenance of breastfeeding. PMID:21655719

  4. Sequence Analysis of a 282-Kilobase Region Surrounding the Citrus Tristeza Virus Resistance Gene (Ctv) Locus in Poncirus trifoliata L. Raf.1

    Science.gov (United States)

    Yang, Zhong-Nan; Ye, Xin-Rong; Molina, Joe; Roose, Mikeal L.; Mirkov, T. Erik

    2003-01-01

    Citrus tristeza virus (CTV) is the major virus pathogen causing significant economic damage to citrus worldwide, and a single dominant gene, Ctv, provides broad spectrum resistance to CTV in Poncirus trifoliata L. Raf. Ctv was physically mapped to a 282-kb region using a P. trifoliata bacterial artificial chromosome library. This region was completely sequenced to about 8× coverage using a shotgun sequencing strategy and primer walking for gap closure. Sequence analysis predicts 22 putative genes, two mutator-like transposons and eight retrotransposons. This sequence analysis also revealed some interesting features of this region of the P. trifoliata genome: a disease resistance gene cluster with seven members and eight retrotransposons clustered in a 125-kb gene-poor region. Comparative sequence analysis suggests that six genes in the Ctv region have significant sequence similarity with their orthologs in bacterial artificial chromosome clones F7H2 and F21T11 from Arabidopsis chromosome I. However, the analysis of gene colinearity between P. trifoliata and Arabidopsis indicates that Arabidopsis genome sequence information may be of limited use for positional gene cloning in P. trifoliata and citrus. Analysis of candidate genes for Ctv is also discussed. PMID:12586873

  5. Sequence analysis of a 282-kilobase region surrounding the citrus Tristeza virus resistance gene (Ctv) locus in Poncirus trifoliata L. Raf.

    Science.gov (United States)

    Yang, Zhong-Nan; Ye, Xin-Rong; Molina, Joe; Roose, Mikeal L; Mirkov, T Erik

    2003-02-01

    Citrus tristeza virus (CTV) is the major virus pathogen causing significant economic damage to citrus worldwide, and a single dominant gene, Ctv, provides broad spectrum resistance to CTV in Poncirus trifoliata L. Raf. Ctv was physically mapped to a 282-kb region using a P. trifoliata bacterial artificial chromosome library. This region was completely sequenced to about 8x coverage using a shotgun sequencing strategy and primer walking for gap closure. Sequence analysis predicts 22 putative genes, two mutator-like transposons and eight retrotransposons. This sequence analysis also revealed some interesting features of this region of the P. trifoliata genome: a disease resistance gene cluster with seven members and eight retrotransposons clustered in a 125-kb gene-poor region. Comparative sequence analysis suggests that six genes in the Ctv region have significant sequence similarity with their orthologs in bacterial artificial chromosome clones F7H2 and F21T11 from Arabidopsis chromosome I. However, the analysis of gene colinearity between P. trifoliata and Arabidopsis indicates that Arabidopsis genome sequence information may be of limited use for positional gene cloning in P. trifoliata and citrus. Analysis of candidate genes for Ctv is also discussed. PMID:12586873

  6. 种植体支持式单端固定桥的临床应用与研究进展%Clinical application and research progress of cantilevered implant-supported fixed partial denture

    Institute of Scientific and Technical Information of China (English)

    钱姝娇

    2015-01-01

    随着口腔种植学科的发展,种植义齿已经被广泛应用于口腔临床修复.在缺牙区牙槽骨骨量严重不足的情况下,种植支持式单端固定桥(implant-supported fixed partial denture with cantilever exten-sion,cantilevered implant-supported fixed partial denture,CIFPD)可以避免复杂外科技术;而在近远中距离不足情况下,选择CIFPD又能有效解决美观问题.然而,临床上对于CIFPD一直存在争议.本文就CIFPD的临床应用与研究进展做一综述.

  7. Opportunity's Surroundings on Sol 1818

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this full-circle view of the rover's surroundings during the 1,818th Martian day, or sol, of Opportunity's surface mission (March 5, 2009). South is at the center; north at both ends. The rover had driven 80.3 meters (263 feet) southward earlier on that sol. Tracks from the drive recede northward in this view. The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and lighter-toned bedrock. This view is presented as a cylindrical projection with geometric seam correction.

  8. Responsible company in responsible surrounding

    OpenAIRE

    Katarzyna Klimkiewicz

    2012-01-01

    The concept of the Corporate Social Responsibility includes long-time view and it is based on the belief that the social and economic interest could be combined. However, the question is, how should the socially-responsible company behave in the situation where the occasional external expectations it is supposed to meet do not harmonize with the long term goals of the company? One can also ask if a responsible company could have a chance to exist in a irresponsible surrounding? This article c...

  9. On the potential of an RST-based analysis of the MODIS-derived chl-a product over Condor seamount and surrounding areas (Azores, NE Atlantic)

    Science.gov (United States)

    Ciancia, Emanuele; Magalhães Loureiro, Clara; Mendonça, Ana; Coviello, Irina; Di Polito, Carmine; Lacava, Teodosio; Pergola, Nicola; Satriano, Valeria; Tramutoli, Valerio; Martins, Ana

    2016-09-01

    Oceanographic cruises have been conducted on the Condor seamount (SW Faial Island, Azores archipelago, NE Atlantic) since 2009 to collect in situ data and understand potential seamount effects on local biodiversity. Satellite data have been concurrently collected to infer the space-time upper-ocean optical property variability and the associated physical processes. The main limitation of this analysis is the persistent and significant cloud coverage above the region that, especially in some seasons, can significantly hinder satellite data availability. This study was meant to test the robust satellite technique (RST) over the Condor seamount, assess its capability to estimate multiyear trends and identify space-time anomalies. To this aim, 11-year MODIS/AQUA level 2-derived chlorophyll-a (chl-a) data were used. Results achieved for October 2010 show, within a large-scale analysis, the presence of well-defined areas of near-surface chl-a anomalies, highlighting the occurrence of a trapping effect due to flow-topography interaction processes. Regarding the Condor area, the chl-a anomalies detected along the eastern side of the seamount were linked to a strong vertical mixing that provided sufficient inorganic nutrients requested for productivity. The achieved results, whose accuracy was also tested through a comparison with in situ data, are consistent with those independently obtained by other authors who described the phytoplankton variability around the Condor seamount. This study shows the high potential of the RST approach to assess the chl-a variability in the space-time domain in oligotrophic regions such as the Azores, allowing the identification of the most important areas to be preserved and/or managed.

  10. On the potential of an RST-based analysis of the MODIS-derived chl-a product over Condor seamount and surrounding areas (Azores, NE Atlantic)

    Science.gov (United States)

    Ciancia, Emanuele; Magalhães Loureiro, Clara; Mendonça, Ana; Coviello, Irina; Di Polito, Carmine; Lacava, Teodosio; Pergola, Nicola; Satriano, Valeria; Tramutoli, Valerio; Martins, Ana

    2016-07-01

    Oceanographic cruises have been conducted on the Condor seamount (SW Faial Island, Azores archipelago, NE Atlantic) since 2009 to collect in situ data and understand potential seamount effects on local biodiversity. Satellite data have been concurrently collected to infer the space-time upper-ocean optical property variability and the associated physical processes. The main limitation of this analysis is the persistent and significant cloud coverage above the region that, especially in some seasons, can significantly hinder satellite data availability. This study was meant to test the robust satellite technique (RST) over the Condor seamount, assess its capability to estimate multiyear trends and identify space-time anomalies. To this aim, 11-year MODIS/AQUA level 2-derived chlorophyll-a (chl-a) data were used. Results achieved for October 2010 show, within a large-scale analysis, the presence of well-defined areas of near-surface chl-a anomalies, highlighting the occurrence of a trapping effect due to flow-topography interaction processes. Regarding the Condor area, the chl-a anomalies detected along the eastern side of the seamount were linked to a strong vertical mixing that provided sufficient inorganic nutrients requested for productivity. The achieved results, whose accuracy was also tested through a comparison with in situ data, are consistent with those independently obtained by other authors who described the phytoplankton variability around the Condor seamount. This study shows the high potential of the RST approach to assess the chl-a variability in the space-time domain in oligotrophic regions such as the Azores, allowing the identification of the most important areas to be preserved and/or managed.

  11. Effect of labiolingual inclination of a maxillary central incisor and surrounding alveolar bone loss on periodontal stress: A finite element analysis

    Science.gov (United States)

    Choi, Sung-Hwan; Kim, Young-Hoon; Lee, Kee-Joon

    2016-01-01

    Objective The aim of this study was to investigate whether labial tooth inclination and alveolar bone loss affect the moment per unit of force (Mt/F) in controlled tipping and consequent stresses on the periodontal ligament (PDL). Methods Three-dimensional models (n = 20) of maxillary central incisors were created with different labial inclinations (5°, 10°, 15°, and 20°) and different amounts of alveolar bone loss (0, 2, 4, and 6 mm). The Mt/F necessary for controlled tipping (Mt/Fcont) and the principal stresses on the PDL were calculated for each model separately in a finite element analysis. Results As labial inclination increased, Mt/Fcont and the length of the moment arm decreased. In contrast, increased alveolar bone loss caused increases in Mt/Fcont and the length of the moment arm. When Mt/F was near Mt/Fcont, increases in Mt/F caused compressive stresses to move from a predominantly labial apical region to a palatal apical position, and tensile stresses in the labial area moved from a cervical position to a mid-root position. Although controlled tipping was applied to the incisors, increases in alveolar bone loss and labial tooth inclination caused increases in maximum compressive and tensile stresses at the root apices. Conclusions Increases in alveolar bone loss and labial tooth inclination caused increases in stresses that might cause root resorption at the root apex, despite the application of controlled tipping to the incisors. PMID:27226961

  12. Displacement Monitoring and Analysis Platform for Highway Tunnel Surrounding Rock Based on Internet Technology%基于互联网技术的公路隧道围岩常规位移监测分析平台

    Institute of Scientific and Technical Information of China (English)

    姜锡宸; 孟陆波; 李天斌; 刘家民

    2015-01-01

    Informationization of tunnel construction management is a trend nowadays.A displacement monitoring and analysis platform for highway tunnel surrounding rocks based on internet technology is developed by using PHP (Personal Home Page)programming language and in conjunction with Mysql data storage function and analysis principles of the least square method and regression model,so as to meet the informationization requirement of highway tunnel monitoring.By using the mentioned platform,the recording and regression analysis of the monitoring data of the highway tunnel,the assessment of the stability of the surrounding rock and the estimation of the final displacement of the surrounding rock and the secondary lining time can be realized.Furthermore,by using the mentioned platform,the technical staffs that are not at the site can obtain the monitoring data and analysis results of the tunnel so that they can make timely adjustment on the lining structure.%信息化是当前隧道施工管理的必然趋势,针对公路隧道监控量测信息化建设要求,采用 PHP 编程语言,结合 Mysql 的数据存储功能、最小二乘法及回归模型的分析原理,研发基于互联网技术的公路隧道围岩常规位移监测分析平台。该平台实现了在网络上对公路隧道监测断面数据的录入存储、回归分析、围岩稳定性判别及隧道围岩最终位移变形量与二次衬砌时间预估等功能。通过网络访问该平台,可使不在现场的参建人员及时掌握隧道监测数据及分析结果,可为支护结构的调整和变更提供更有效率的依据,进而提高公路隧道的管理效率。

  13. Opportunity's Surroundings on Sol 1687

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this 360-degree view of the rover's surroundings on the 1,687th Martian day, or sol, of its surface mission (Oct. 22, 2008). Opportunity had driven 133 meters (436 feet) that sol, crossing sand ripples up to about 10 centimeters (4 inches) tall. The tracks visible in the foreground are in the east-northeast direction. Opportunity's position on Sol 1687 was about 300 meters southwest of Victoria Crater. The rover was beginning a long trek toward a much larger crater, Endeavour, about 12 kilometers (7 miles) to the southeast. This view is presented as a cylindrical projection with geometric seam correction.

  14. Opportunity's Surroundings on Sol 1798

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this 180-degree view of the rover's surroundings during the 1,798th Martian day, or sol, of Opportunity's surface mission (Feb. 13, 2009). North is on top. The rover had driven 111 meters (364 feet) southward on the preceding sol. Tracks from that drive recede northward in this view. For scale, the distance between the parallel wheel tracks is about 1 meter (about 40 inches). The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and lighter-toned bedrock. This view is presented as a cylindrical projection with geometric seam correction.

  15. 某水工隧洞围岩稳定及支护结构分析%ANALYSIS ON SURROUNDING ROCK STABILITY AND SUPPORTING STRUCTURE OF DIVERSION SPILLWAY TUNNEL

    Institute of Scientific and Technical Information of China (English)

    秦雷; 郭德发; 王庆

    2012-01-01

    隧洞的围岩稳定及支护结构安全是保证隧洞安全、实现隧洞功能的关键因素.由围岩加固圈承担主要的外水压力是优化支护结构设计、保证围岩稳定的一种有效方法.建立肯斯瓦特导流泄洪洞三维有限元模型,并进行非线性有限元分析.分析结果表明,设计的支护措施能明显减少围岩变形、改善应力分布,为类似工程设计提供参考.%The stability of surrounding rock tunnel and the safe of support structure is the key factor to ensure tunnels safe and to achieve tunnel function. It is a optimized design to exert major external water pressure at reinforce circle also it is an effective method for the stability of surrounding rock. The author did the nonlinear finite element analysis by creating three-dimensional finite element model of Kensi-wate diversion spillway tunnel. The results show that the designed support measures can significantly reduce the rock deformation and improve the stress distribution,and it can provide a reference for the design of similar projects.

  16. 不衬砌水工隧洞围岩稳定性数值模拟分析%Numerical simulation analysis for surrounding rock stability of unlined high pressure hydraulic tunnels

    Institute of Scientific and Technical Information of China (English)

    刘新颖; 曹平; 刘涛影; 梅慧浩; 宁果果

    2012-01-01

    Aiming at the phenomena that hyperosmolar role will not only change the stress state of rock and soil, but also cause the rock splitting , destroy the original structure of the rock. Based on the coupled fluid - solid theorem, numerical analysis for the stability of tunnel surrounding rock was done with fast Lagrangian analysis of continua in three - dimension (FLAC3D). Based on the surrounding rock stability considering percolation and the surrounding rock characteristics with the internal water fluid as main research aspects, the stress field and displacement field feature after rock excavation, feedback of excavation on seepage field, evolution trend of failure characteristics and hydraulic characteristics of the tunnel under the role of internal water was achieved. The research results can provide a theoretical basis for corresponding safety measurement in construction process and waterproofing of tunnel in aquifer condition.%针对高渗压作用不仅会改变岩土体的应力状态,同时可能会使岩体劈裂、破坏岩体的原有结构的现象,基于流固耦合分析理论,利用快速拉格朗日有限差分法对隧洞围岩稳定性进行分析.从考虑渗流效应时围岩开挖稳定性、内水作用下围岩力学特性方面开展研究,得到围岩开挖后应力场、位移场分布特征,开挖卸载对渗流场的反馈,内水作用下隧洞的破坏特征和水力特性演变趋势.研究结果表明:对隧洞施工过程中采取安全措施,富水条件下的隧洞工程防排水提供一定的理论参考.

  17. Binaural Rendering in MPEG Surround

    Directory of Open Access Journals (Sweden)

    Kristofer Kjörling

    2008-04-01

    Full Text Available This paper describes novel methods for evoking a multichannel audio experience over stereo headphones. In contrast to the conventional convolution-based approach where, for example, five input channels are filtered using ten head-related transfer functions, the current approach is based on a parametric representation of the multichannel signal, along with either a parametric representation of the head-related transfer functions or a reduced set of head-related transfer functions. An audio scene with multiple virtual sound sources is represented by a mono or a stereo downmix signal of all sound source signals, accompanied by certain statistical (spatial properties. These statistical properties of the sound sources are either combined with statistical properties of head-related transfer functions to estimate “binaural parameters” that represent the perceptually relevant aspects of the auditory scene or used to create a limited set of combined head-related transfer functions that can be applied directly on the downmix signal. Subsequently, a binaural rendering stage reinstates the statistical properties of the sound sources by applying the estimated binaural parameters or the reduced set of combined head-related transfer functions directly on the downmix. If combined with parametric multichannel audio coders such as MPEG Surround, the proposed methods are advantageous over conventional methods in terms of perceived quality and computational complexity.

  18. 双种植体修复下颌第一磨牙缺失临床效果观察%Double Implant-Supported Single Crown for the Absence of Mandibular First Molar

    Institute of Scientific and Technical Information of China (English)

    刘自力; 贺美兰

    2011-01-01

    目的 探讨双种植体修复下颌第一磨牙缺失的临床效果.方法 对38例下颌第一磨牙缺失患者,39个宽间隙,每间隙各植入2颗种植体,共植入BLB系统种植体78颗,并以单冠修复,观察1~8年,从种植成功率及患者满意度两方而评价临床效果.结果 观察期间,种植修复成功率为100%,患者满意度为97.4%.结论 双种植体单冠修复宽间隙下颌第一磨牙缺失临床效果满意.%Objective To study the clinical effects of implant restoration of double implant-supported single crown for the absence of mandibular first molar. Methods Thirty-eight patients who lost mandibular first molar with wide space were treated by BLB double implant-supported single crown, then the clinical effects were evaluated by implant successful ratio and patients satisfactory ratio during 1 - 8 years. Results During the follow - up, the implant successful ratio was 100% and the patients satisfactory ratio was 97.4%. Conclusion The clinical effects of double implant-supported single crown for the absence of lower first molar is satisfactory.

  19. Control of Formation of Lithological Reservoirs by Surrounding Mudstone

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Taking the Jiyang depression as an example, this paper discusses the control of the formation of lithological reservoir by surrounding rocks by integrated application of geological analysis, physical simulation, and the analysis of oil & gas accumulation mechanism. Geological statistical shows that the major burial depth and interval of lithological reservoirs in the Jiyang depression are related to the hydrocarbon generation in and expulsion from the Lower Tertiary source rocks and the time of the formation of most lithological reservoirs coincides with the peak of hydrocarbon generation and expulsion. The lithological traps located in the center of effective source rocks are propitious to high oil saturation than those located on the margin of effective source rocks. The hydrocarbon charge degree of the lithological reservoir has a positive correlation with the intensity of hydrocarbon expulsion from surrounding source rocks.Geological analyses and NMR experiments also show that the oil saturation of surrounding source rocks control the hydrocarbon potential of lithological traps, and a critical value for oil saturation of surrounding mudstone is required, that is, when the oil saturation of surrounding mudstone is lower than this critical value, no oil and gas accumulate in the lithological trap. The control of surrounding mudstone on the oil-bearing properties of lithological reservoirs is also analyzed by the mechanisms of hydrocarbon generation and expulsion as well as accumulation.

  20. 下颌双侧游离端磨牙缺失种植覆盖义齿修复的光弹模型建立%Establishment of a mandibular bilateral distal-extension edentulous photoelastic model of implant-supported overdentures

    Institute of Scientific and Technical Information of China (English)

    李宇; 张少锋; 宋芳; 柴治国; 王少海; 沈丽娟

    2012-01-01

    目的:建立下颌双侧游离端缺牙种植覆盖义齿修复的光弹模型,为研究不同上部结构种植覆盖义齿种植体及其基牙周围支持组织的应力状况提供基础模型.方法:以环氧树脂模拟下颌骨,硅橡胶模拟牙槽黏膜和牙周膜,采用临床常用种植体和3种上部附着结构,按临床实际操作步骤制得双种植体支持的下颌双侧游离端缺牙种植覆盖义齿修复的光弹模型.结果:制得含种植体的环氧树脂光弹模型呈淡黄色,质地均匀,透明,无初应力;牙体、牙槽骨、牙周膜的弹性模量之比及基牙牙周膜和缺牙区黏膜厚度与临床实际相接近,并能够在保持模型其他条件不变的情况下方便的替换种植覆盖义齿上部附着结构.结论:所建模型可用于不同上部结构种植覆盖义齿种植体及其基牙周围支持组织的应力分析.%AIM- To establish a mandibular bilateral distal-extension edentulous photoelastic model for a-nalysis of stress distribution in the supporting structure around the implants on implant-supported overdentures. METHODS: Photoelastic ethoxyline resin and silicone rubber gum were used to simulate the mandible and the alveolar mucosa respectively. Using the commonly used implants and 3 types of upper attachments, the 2-implant supported mandibular overdentures photoelastic model was made. RESULTS; The ethoxyline resin model was faintly yellow, homogeneous, transparent, and had no natural stress. The elastic modulus ratio of teeth, alveolar bone, periodontal ligament and the thickness of periodontal ligament, edentulous ridge mucosa were close to actual clinical data. The attachment structure could be replaced conveniently without changing other parts of the model. CONCLUSION: The model is applicable to qualitative analysis of stress distribution in the supporting structure around the implants.

  1. Intelligent Displacement Back Analysis of Surrounding Rock Parameters of the Mined Subway Tunnel in Changchun%长春地铁暗挖隧道围岩参数智能位移反分析

    Institute of Scientific and Technical Information of China (English)

    王志斌; 麻凤海; 张碧雪

    2015-01-01

    为了更加真实的反映岩土体整体特性主要力学参数的取值,以长春地铁某暗挖区间现场监测位移值为依据,通过敏感性分析,确定了该地区对地表变形影响最大的力学参数为弹性模量 E和内摩擦角φ,运用Madis GTS三维正算模型、BP神经网络模型组成的智能位移反分析系统对其进行了反分析。运用反分析得到的参数值进行数值模拟,将得到的监测断面位移值与实测值进行了对比,并根据断面的位移云图对隧道围岩的稳定性进行了评价,验证了反分析结果的合理性和准确性。%In order to determine the value of the main mechanical parameters that could truely reflect the global property of rock and soil ,the mining section of Changchun subway was taken as the engineering background ,and it was confirmed that the mechanical parameters with the greatest impact on the surface deformation were the elasticity modulus E and in-ternal friction angle φ,based on the sensitivity analysis of the field monitoring displacement data .And then the intelli-gent displacement back analysis system formed by the Midas GTS 3D forward solution model and BP neural network was applied for the back analysis of these parameters .The new parameters obtained from the back analysis were used in the simulation analysis ,and the displacement value was calculated and then compared with the monitoring data .According to the displacement cloud picture of the section ,the stability of the tunnel surrounding rock was evaluated ,and the rational-ity and accuracy of the back analysis result was verified .

  2. Contour detection by surround suppression of texture

    NARCIS (Netherlands)

    Petkov, Nicolai; Tavares, JMRS; Jorge, RMN

    2007-01-01

    Based on a keynote lecture at Complmage 2006, Coimbra, Oct. 20-21, 2006, an overview is given of our activities in modelling and using surround inhibition for contour detection. The effect of suppression of a line or edge stimulus by similar surrounding stimuli is known from visual perception studie

  3. Analysis of the Surrounding Environment Influence Caused by Rectangular Pipe Jacking Construction in Shanghai%上海地区某大口径矩形顶管施工周边环境影响监测分析

    Institute of Scientific and Technical Information of China (English)

    孙亚峰

    2015-01-01

    顶管技术作为非开挖的技术中的一种,可以在不用开挖地表土的情况下将管道铺设完毕,具有其他开挖方式无可比拟的优点,其应用也越来越广泛。但是在顶管施工中,不可避免地会破坏管道周围土体原有的平衡,造成地面的沉降,对周边环境造成影响。相对于圆形顶管,矩形顶管对周围土体的扰动更大,从而引起的地面变形也更大。本文以上海市徐汇区某地下通道矩形顶管工程为背景,通过现场监测数据分析,得出了一些有益的结论。%As one of Trench less Technology ,Pipe jacking has the unparalleled advantage of finishing pipeline laying without excavating surface soil ,and has become widely used .However ,pipe jacking will inevitably break the original soil balance around the pipe ,leading to land subsidence and affect buildings surrounded ,even endangers their safety .Rela-tive to circular pipe jacking ,rectangular pipe jacking construction may disturb the soil more heavily and cause more sur-face deformation.This thesis based on the rectangular pipe jacking construction project of Shanghai Xuhui District under -ground passage .Through on-site monitoring data analysis ,some useful conclusions are obtained .

  4. iTRAQ analysis of hepatic proteins in free-living Mus spretus mice to assess the contamination status of areas surrounding Doñana National Park (SW Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Abril, Nieves; Chicano-Gálvez, Eduardo; Michán, Carmen; Pueyo, Carmen; López-Barea, Juan, E-mail: bb1lobaj@uco.es

    2015-08-01

    This work aims to develop and integrate new -omics tools that would be applicable to different ecosystem types for a technological updating of environmental evaluations. We used a 2nd-generation (iTRAQ-8plex) proteomic approach to identify/quantify proteins differentially expressed in the liver of free-living Mus spretus mice from Doñana National Park or its proximities. Mass spectrometry was performed in an LTQ Orbitrap system for iTRAQ reporter ion quantitation and protein identification using a Mus musculus database as reference. A prior IEF step improved the separation of the complex peptide mixture. Over 2000 identified proteins were altered, of which 118 changed by ≥ 2.5-fold in mice from at least two problem sites. Part of the results obtained with the iTRAQ analysis was confirmed by Western blot. Over 75% of the 118 proteins were upregulated in animals captured at polluted sites and only 16 proteins were downregulated. Upregulated proteins were involved in stress response; cell proliferation and apoptosis; signal transduction; metastasis or tumour suppression; xenobiotic export or vesicular trafficking; and metabolism. The downregulated proteins, all potentially harmful, were classified as oncoproteins and proteins favouring genome instability. The iTRAQ results presented here demonstrated that the survival of hepatic cells is compromised in animals living at polluted sites, which showed deep alterations in metabolism and the signalling pathways. The identified proteins may be useful as biomarkers of environmental pollution and provide insight about the metabolic pathways and/or physiological processes affected by pollutants in DNP and its surrounding areas. - Highlights: • iTRAQ quantitation was used for the first time to monitor a wildlife reserve • Over 2,000 proteins with altered expression were identified in problem Doñana sites • Of them, 118 changed over 2.5-fold in, at least, two problem sites • Upregulation of protective proteins

  5. 种植体支持义齿患者骨感知的大脑皮层适应性初步研究%Neuroplasticity in patients with implant supported full dentures

    Institute of Scientific and Technical Information of China (English)

    陈琰; 林野; 李科; 李健慧; 邸萍; 金真

    2009-01-01

    Objective To investigate the potential mechanism of "osseopereepfion" which is the sensory and motor experience associated with dental implants. Methods Twenty patients with implant supported full dentures or traditional full dentures were recruited in this study. Functional MRI (fMRI) scan covering the whole brain was carried out in these patients in clenching. The fMRI data were analyzed with SPM 99 software. Results In implant supported removable denture group, increased blood oxyen level dependent (BOLD) signals during clenching were found in prefrontal cortex, premotor cortex, superior parietal cortex, basal ganglion and thalamus. In implant supported fixed denture group, main activations were found in prefrontal cortex, primary sensory and motor cortex, Broca's area, premotor cortex, superior temporal cortex, insular, basal ganglion, thalamus and hippocampus. In traditional full denture group,significant activations were mainly found in prefrontal cortex, premotor cortex. Their activation maps showed the greatest individually dependent diversity. Conclusions Sensory and motor feedback of central nervous system in patients with implant support fixed dentures is close to that of natural dentition. Mastication with traditional full dentures is more likely a process of task learning, memory and adaptation, which might be a more individually dependent restoration.%目的 采用功能性核磁共振成像(functional MRI,fMBl)对"骨感知"的中枢神经基础进行初步探讨.方法 研究对象为北京大学口腔医学院·口腔医院种植中心2005-2007年无牙颌种植修复复查患者和无牙颌初诊患者20例,共分为3组进行紧咬状态的fMRI扫描,SPM 99软件包统计分析及结果判定.结果 常规全口义齿修复(A组=8例)患者在前额叶皮层激活显著,而与咀嚼运动相关的初级感觉运动皮层激活人数较少;种植体支持固定义齿(B组=3例)患者在紧咬时皮层激活与天然牙

  6. 种植支持式单端固定桥斜向集中载荷下的三维位移%Three-dimensional Displacement of Implant-supported Cantilever Fixed Partial Denture under Oblique Loading

    Institute of Scientific and Technical Information of China (English)

    王宏仁; 李爱洁; 陈新民

    2013-01-01

    本实验旨在研究种植支持式单端固定桥(CFPD)斜向集中受载时的三维位移.采用比格犬下颌骨作为实验对象,即刻种植ITI种植体两枚,建立以两种植体为基牙的种植支持式CFPD,采用数字激光散斑技术测量其在斜向加载时不同加载量下的三维位移.结果表明:斜向加载桥体时,随着载荷量的增加,基牙和桥体的位移量随之增大.在相同载荷下,桥体位移量最大,近缺隙侧基牙位移量次之,远缺隙侧基牙位移量最小;斜向加载基牙时,相应受载基牙位移量最大,桥体和邻近基牙位移量次之.在相同加载条件下,加载基牙时CFPD的位移量较加载桥体时的位移量小.因此,可认为种植支持式CFPD是一种可行的修复方式,但是在使用过程中要避免斜向受力,尤其是桥体的斜向受力.%The purpose of this study was to research the three-dimensional displacements of implant-supported cantilever fixed partial denture (CFPD) under oblique loading.One Beagle dog was used in this experiment.Two immediate implants of ITI were inserted in the mandible of the dog,and the implant-supported CFPD which used the implants as abutments was made in vitro fresh mandible.Then the digital laser speckle technique was employed to measure the three-dimensional displacements of CFPD under different oblique loading.We found that when an oblique loading was exerted on the pontic,the displacement increased with increasing of load.Under equal loading,the displacement of the abutment near to the pontic was smaller than that of the pontic but greater than that of the abutment far from the pontic.When oblique loading was exerted on the abutment,the displacement of the direct loaded abutment was greater than that of the other abutment and the pontic.Under the equal loading,the displacement of implant-supported CFPD of loading on pontic was greater than that of loading on abutments.The experiments demonstrated that implant-supported cantilever

  7. The biological activity of propolis-containing toothpaste on oral health environment in patients who underwent implant-supported prosthodontic rehabilitation.

    Science.gov (United States)

    Morawiec, Tadeusz; Dziedzic, Arkadiusz; Niedzielska, Iwona; Mertas, Anna; Tanasiewicz, Marta; Skaba, Dariusz; Kasperski, Jacek; Machorowska-Pieniążek, Agnieszka; Kucharzewski, Marek; Szaniawska, Karolina; Więckiewicz, Włodzimierz; Więckiewicz, Mieszko

    2013-01-01

    The soft and periodontal tissues surrounding dental implants are particularly susceptible to bacteria invasion and inflammatory reactions due to complex histological structures. This study was carried out to investigate the influence of a propolis-containing hygienic agent on selected oral health parameters, oral microflora, and the condition of periodontal health. Sixteen subjects who underwent an oral rehabilitation with dental implants were selected and randomly assigned into two groups, which received a newly formulated propolis-containing toothpaste (3% (CA)) or a negative control without an active ingredient (CC). Approximal plaque index (API), oral hygiene index (OHI, debris component), and sulcus bleeding index (SBI) were assessed in three subsequent stages. During the first and last examinations, the swabs were employed for microbiological inoculation. Propolis-containing toothpaste was found to be distinctively effective in improving oral health and the occurrence of gingivitis triggered by dental plaque. The qualitative and quantitative changes in oral bacteria spectrum were observed. Antibacterial measures containing propolis might be used as a natural adjuvant to other active substances in individuals with a high risk of periodontal problems against pathogenic oral microflora. PMID:23762153

  8. The Biological Activity of Propolis-Containing Toothpaste on Oral Health Environment in Patients Who Underwent Implant-Supported Prosthodontic Rehabilitation

    Directory of Open Access Journals (Sweden)

    Tadeusz Morawiec

    2013-01-01

    Full Text Available The soft and periodontal tissues surrounding dental implants are particularly susceptible to bacteria invasion and inflammatory reactions due to complex histological structures. This study was carried out to investigate the influence of a propolis-containing hygienic agent on selected oral health parameters, oral microflora, and the condition of periodontal health. Sixteen subjects who underwent an oral rehabilitation with dental implants were selected and randomly assigned into two groups, which received a newly formulated propolis-containing toothpaste (3% (CA or a negative control without an active ingredient (CC. Approximal plaque index (API, oral hygiene index (OHI, debris component, and sulcus bleeding index (SBI were assessed in three subsequent stages. During the first and last examinations, the swabs were employed for microbiological inoculation. Propolis-containing toothpaste was found to be distinctively effective in improving oral health and the occurrence of gingivitis triggered by dental plaque. The qualitative and quantitative changes in oral bacteria spectrum were observed. Antibacterial measures containing propolis might be used as a natural adjuvant to other active substances in individuals with a high risk of periodontal problems against pathogenic oral microflora.

  9. The biological activity of propolis-containing toothpaste on oral health environment in patients who underwent implant-supported prosthodontic rehabilitation.

    Science.gov (United States)

    Morawiec, Tadeusz; Dziedzic, Arkadiusz; Niedzielska, Iwona; Mertas, Anna; Tanasiewicz, Marta; Skaba, Dariusz; Kasperski, Jacek; Machorowska-Pieniążek, Agnieszka; Kucharzewski, Marek; Szaniawska, Karolina; Więckiewicz, Włodzimierz; Więckiewicz, Mieszko

    2013-01-01

    The soft and periodontal tissues surrounding dental implants are particularly susceptible to bacteria invasion and inflammatory reactions due to complex histological structures. This study was carried out to investigate the influence of a propolis-containing hygienic agent on selected oral health parameters, oral microflora, and the condition of periodontal health. Sixteen subjects who underwent an oral rehabilitation with dental implants were selected and randomly assigned into two groups, which received a newly formulated propolis-containing toothpaste (3% (CA)) or a negative control without an active ingredient (CC). Approximal plaque index (API), oral hygiene index (OHI, debris component), and sulcus bleeding index (SBI) were assessed in three subsequent stages. During the first and last examinations, the swabs were employed for microbiological inoculation. Propolis-containing toothpaste was found to be distinctively effective in improving oral health and the occurrence of gingivitis triggered by dental plaque. The qualitative and quantitative changes in oral bacteria spectrum were observed. Antibacterial measures containing propolis might be used as a natural adjuvant to other active substances in individuals with a high risk of periodontal problems against pathogenic oral microflora.

  10. Clinical Pathway Study of Implant-supporting Fixed and Removable Prostheses in Edentulous Patients%牙列缺失行种植体支持式可摘义齿修复临床路径

    Institute of Scientific and Technical Information of China (English)

    张在德

    2012-01-01

    目的:探讨临床路径的应用对牙列缺失行种植体支持式可摘义齿修复的临床效果.方法:对照组66例采用常规方法进行临床治疗和护理;研究组60例患者均采用我院自编自制的临床路径进行治疗与护理.结果:研究组患者治疗疗效明显优于对照组,数据经统计学比较具有显著差异(P<0.05).研究组患者满意度明显高于对照组,数据经统计学比较具有显著差异(P<0.05).结论:临床路径可提高牙列缺失行种植体支持式可摘义齿修复术的临床疗效,提高治疗效率和患者满意度.%Objective:To discuss the clinical effects of implant-supporting fixed and removable prostheses in edentulous patients. Methods:66 cases in Control group were treated by traditional treatment and nursing.60 cases in Study group were treated by homemade clinical pathway of our hospital.Results:The clinical effects of Study group was significantly higher than Control group,and the patients' satisfaction was significantly higher than Control group (P<0.05).Conclusion:Clinical pathway can improve the effects,efficiency and satisfaction of implant-supporting fixed and removable prostheses in edentulous patients.

  11. Research progress on implant-supported magnet-retained overdenture for edentulous denture%磁性附着体在种植全口覆盖义齿中的应用进展

    Institute of Scientific and Technical Information of China (English)

    齐佳妮; 兰晶

    2014-01-01

    The use of magnetic attachments in implant restoration has gradually increased and has been accepted by clinicians and patients because of its convenient and fast laboratory and clinical chairside treatment, short treatment course, relatively low cost, easy maintenance for patients, and relatively few complications. Effective choice of proper implant-supported magnet-retained overdenture is a key factor in magnetic attachment for edentulous patients. In this article, we review the literature on certain patient and physician concerns about implant-supported magnet-retained overdenture, namely, corrosion, biocompatibility, retention and stability, masticatory function, maintenance after implant restoration, and patient satisfaction.%近年来,磁性附着体在种植修复中的应用逐渐增加,由于其具有实验室和临床椅旁处理简便快捷、疗程短、费用相对较低、患者易于维护、并发症相对少等特点,受到了临床医生和患者的欢迎。如何有效地选择使用种植体支持的磁性附着体成为应用磁性附着体解决牙列缺失患者的关键点。本文就患者和医生关心的应用于种植修复中磁性附着体的腐蚀,磁性附着体的生物相容性、固位力和稳定性、咀嚼功能、种植修复后的维护以及患者的满意度等问题进行综述。

  12. The clinical effect of the locator attachment used in implant-supported overdentures%Locator附着体固位的种植覆盖义齿临床效果观察

    Institute of Scientific and Technical Information of China (English)

    张健; 马晓丽; 杨晶; 王庆福; 朱甄慧; 王文慧

    2012-01-01

    Objective To evaluate the clinical effect of the locator attachment used in implant-supported overdentures. Methods A total of 22 edentulous patients were enrolled in the study. The patients were treated with Locator attachments used in implant-supported overdentures.The follow-up time was 3 year.The patients' feeling,clinical study,X ray study were recorded and evaluated. Results No implant was failed within 3 year,the mean bone loss was 0.4±0.5mm, all patients were satisfactory with their overdentures. Conclusion Within the limits of the present study,the locator system was recommended for the patients with edentulous jaws.%目的 观察Locator附着体固位的种植覆盖义齿的临床效果.方法 对22例采用Locator附着体固位的种植覆盖义齿患者进行随访3年,并对患者的主观感受、临床检查及X线检查结果进行统计分析.结果 在3年随访期内,所有种植体无松动,平均骨吸收为0.4±0.5mm,患者满意度高.结论 Locator附着体固位的种植覆盖义齿是牙列缺失患者可靠的修复方式.

  13. 无牙颌的种植义齿支持式固定修复——附1例病例报道%Implant-supported Fixed Restoration for the Fully Edentulous: Case Report

    Institute of Scientific and Technical Information of China (English)

    夏雯; 陈江; 黄文秀; 杜志斌

    2011-01-01

    Objective: To discuss the advantages and experiences of implant-supported fixed restoration for the fully edentulous. Methods: One clinical case was performed completed prosthesis process in our department. Clinical and X-ray examination were conducted. Results: No implant failed within 36 months representing three-years survival rate was 100%. No infections, nerve or sinus injury, or other complications occurred during the study. All implants achieved osseointegration before wearing denture. Patients were satisfied with the treatment. Conclusions: Implant supported fixed restoration is a predictable and reliable treatment for edentulous patients.%目的:探讨无牙颌固定式种植义齿修复模式和临床应用体会,为无牙颌患者的临床治疗提供一些有意义的参考.方法:报道1例全口无牙颌患者的种植修复诊疗全过程及3年追踪观察的临床疗效.结果:19枚种植体术中及术后均未发生感染及神经损伤等并发症,修复前均达到骨结合;义齿固位效果良好,达到患者对美观和功能的要求,疗效满意.结论:全口无牙颌的种植义齿支持式固定修复可有效恢复咀嚼功能,改善患者容貌,临床效果可靠,是一种值得推广的无牙颌修复方式.

  14. Simulation of Surrounding Vehicles in Driving Simulators

    OpenAIRE

    Olstam, Johan

    2009-01-01

    Driving simulators and microscopic traffic simulation are important tools for making evaluations of driving and traffic. A driving simulator is de-signed to imitate real driving and is used to conduct experiments on driver behavior. Traffic simulation is commonly used to evaluate the quality of service of different infrastructure designs. This thesis considers a different application of traffic simulation, namely the simulation of surrounding vehicles in driving simulators. The surrounding tr...

  15. 窄煤柱综放回采巷道围岩稳定性分析及控制技术∗%Stability analysis and control technology of surrounding rock in fully mechanized mining roadway with narrow coal pillars

    Institute of Scientific and Technical Information of China (English)

    王虎胜; 黄肖; 席朝东; 杨亚峰; 贺冲冲; 刘斌慧

    2015-01-01

    Based on the geological and production conditions of haulage roadway at No.2304 fully mechanized caving face in Guozhuang Coal Mine,the stress distribution characteristics of surrounding rocks in gob-side entry driving with different coal pillar width were deeply analyzed by numerical simulation.Through building the arc triangular block structure model for gob-side entry driving in fully mechanized caving face,the mechanism of the surrounding rock stability was revealed.According to the present roadway support theories,the surrounding rock control technology was proposed,which is a resin extended and high-strength rock bolting and anchor ca-ble reinforcement system.Field practical application showed that the supporting scheme had obvi-ous effect on surrounding rock deformation control in gob-side driving entry of the fully mecha-nized caving face.%基于郭庄煤矿2304综放面运输巷具体地质及生产条件,采用数值模拟对不同煤柱宽度下沿空掘巷围岩应力分布特征进行深入分析。通过构建综放沿空掘巷弧形三角块结构模型,揭示综放面沿空掘巷围岩稳定性机理。根据现有巷道支护理论,提出树脂加长锚固高强锚杆支护系统并进行锚索补强的围岩控制技术。现场实践应用表明:支护方案对综放沿空掘巷围岩变形控制效果显著。

  16. Análise de conteúdo e análise do discurso: o lingüístico e seu entorno Content analysis and discourse analysis: the linguistic and its surroundings

    Directory of Open Access Journals (Sweden)

    Décio Rocha

    2006-01-01

    Full Text Available A partir de um histórico da Análise de Conteúdo e de uma reflexão acerca de suas implicações no contexto do behaviorismo americano do início do século XX, procuraremos neste artigo abordar o conceito de condições de produção enquanto meio de apreensão da relação entre texto e contexto. Os resultados obtidos indicam que, no que concerne à noção de condições de produção, não houve nem uma total ruptura, nem uma simples continuidade entre os trabalhos produzidos segundo a tradição da Análise de Conteúdo e da Sociolingüística, por um lado, e, por outro, a Análise do Discurso concebida por Pêcheux.Based on a historical review of Content Analysis and a debate about its implications in the context of American behaviourism of the beginning of the XX century, the aim of this paper is to focus on the concept of conditions of production as a means of approaching the relationship between text and context. The results show some evidence that, in what concerns the notion of conditions of production, there has been neither total disruption nor simple continuity between tradition (works in Content Analysis and Sociolinguistics and Discourse Analysis as conceived by Pêcheux.

  17. Clinical effect of implant-supported complete denture of patients with moderate to severe chronic periodontitis%全颌种植义齿修复慢性中重度牙周炎的临床疗效

    Institute of Scientific and Technical Information of China (English)

    朱晶; 汪振华

    2012-01-01

    Objective To investigate the clinical effect of implant-supported complete denture of patients with moderate to severe chronic periodontitis. Methods To analyze retrospectively of clinical data of 24 patients with moderate to severe chronic periodontitis, the group of patients were given the treatment of edentulous implant denture after disease control the, to evaluate the repairing effect according to patients' complaints, clinical and radiographic evaluation. Results There were 216 cases of implants were implanted in 20 dental arch, 2 of them were immediate implant in postoperative 3 weeks off, then the implant retention rate was 97.3%, the average retention rate was 97.7%. Implant 46 months average loading, all implants were not loose. The average height for bone resorption was (1.73+0.13) mm. Conclusion The implant-supported complete denture to chronic moderate to severe periodontitis can reduce the absorption of alveolar bone, shorten implant treatment, but at the same time should adhere to regular oral care.%目的 探讨全颌种植义齿修复慢性中重度牙周炎的临床疗效.方法 回顾性分析24例慢性中重度牙周炎患者的临床资料,该组患者经牙周治疗病情控制后采用全颌种植义齿修复,根据患者主诉、临床及X线评价修复效果.结果 共216枚种植体植入20个牙弓,其中有2枚即刻种植于术后3周脱落,即可种植体的保留率为97.3%,种植体平均保留率为97.7%.种植体平均承载42个月,所有种植体均无松动.骨吸收高度平均为(1.73±0.13)mm.结论 采用全颌种植义齿修复慢性中重度牙周炎可减少牙槽骨的吸收,缩短种植修复疗程,但同时要坚持定期的口腔护理.

  18. Smart Chips for Smart Surroundings - 4S

    NARCIS (Netherlands)

    Schuler, Eberhard; König, Ralf; Becker, Jürgen; Rauwerda, Gerard; Burgwal, van de Marcel; Smit, Gerard J.M.; Cardoso, João M.P.; Hübner, Michael

    2011-01-01

    The overall mission of the 4S project (Smart Chips for Smart Surroundings) was to define and develop efficient flexible, reconfigurable core building blocks, including the supporting tools, for future Ambient System Devices. Reconfigurability offers the needed flexibility and adaptability, it provid

  19. Vibrations of machine foundations and surrounding soil

    NARCIS (Netherlands)

    Van Koten, H.; Hoogenboom, P.C.J.

    2012-01-01

    Rotating or pulsing machines are often placed on concrete foundations supported by soil. The machines cause vibrations in the building and in the surrounding soil. This paper provides information, formulas and calculation examples to predict these vibrations. The formulas have been experimentally te

  20. Electromagnetic responses of surrounding environment to nuclear explosion excitation

    International Nuclear Information System (INIS)

    Nuclear explosion (NE) disturbes electromagnetic (EM) balance in a surrounding environmental. When a spherical symmetry of an environment around the center of NE, is disturbed, consequences of influence of EN disturbance are felt on a distance. By analysis of response for the characteristic cases of disturbed symmetry, dimensions were estimated of a source zone of EM disturbance, as well as form and expected intensity of influence on distance for a near ground, air and ionospheric NE. (author)

  1. Impacts of Artificial Reefs on Surrounding Ecosystems

    Science.gov (United States)

    Manoukian, Sarine

    Artificial reefs are becoming a popular biological and management component in shallow water environments characterized by soft seabed, representing both important marine habitats and tools to manage coastal fisheries and resources. An artificial reef in the marine environment acts as an open system with exchange of material and energy, altering the physical and biological characteristics of the surrounding area. Reef stability will depend on the balance of scour, settlement, and burial resulting from ocean conditions over time. Because of the unstable nature of sediments, they require a detailed and systematic investigation. Acoustic systems like high-frequency multibeam sonar are efficient tools in monitoring the environmental evolution around artificial reefs, whereas water turbidity can limit visual dive and ROV inspections. A high-frequency multibeam echo sounder offers the potential of detecting fine-scale distribution of reef units, providing an unprecedented level of resolution, coverage, and spatial definition. How do artificial reefs change over time in relation to the coastal processes? How accurately does multibeam technology map different typologies of artificial modules of known size and shape? How do artificial reefs affect fish school behavior? What are the limitations of multibeam technology for investigating fish school distribution as well as spatial and temporal changes? This study addresses the above questions and presents results of a new approach for artificial reef seafloor mapping over time, based upon an integrated analysis of multibeam swath bathymetry data and geoscientific information (backscatter data analysis, SCUBA observations, physical oceanographic data, and previous findings on the geology and sedimentation processes, integrated with unpublished data) from Senigallia artificial reef, northwestern Adriatic Sea (Italy) and St. Petersburg Beach Reef, west-central Florida continental shelf. A new approach for observation of fish

  2. TBM水平支撑不同接触面积下的围岩稳定性分析%Stability analysis of surrounding rock of TBM gripper with different contact areas

    Institute of Scientific and Technical Information of China (English)

    孙伟; 凌静秀; 霍军周; 邓立营; 巫思荣; 党军锋

    2013-01-01

      针对全断面岩石掘进水平支撑在不稳定地质条件下,易出现支撑不稳、刀盘下沉等问题,基于ANSYS/LS⁃DYNA有限元仿真平台,以II类和V类围岩为研究对象,建立支撑靴在脉动载荷作用下撑紧围岩的数值仿真模型。提取了围岩的等效应力、支撑反力变化规律及材料失效质量。研究结果表明:水平支撑基本能够适应II类围岩,而在V类围岩中容易出现失稳,随着接触面积的下降,支撑力出现具有明显的阶跃性质,失稳时刻也逐渐提前,反映出水平支撑对软弱围岩的不适应,为支撑靴的结构设计和地质适应性提供参考依据。%In order to avoid the shortcomings of the TBM gripper, such as instability of rock supports and cutter head subsidence, while it works in the unstable geology conditions, based on the finite element simulation platform of ANSYS/LS⁃DYNA, the researchers constructed a numerical simulation model of interaction between a gripper and rock under the pulsating load using type II and V surrounding rocks as their research objects. Next, the equiva⁃lent stress, and support reaction change rule, as well as the mass failure of surrounding rock were obtained. The re⁃sults showed that the gripper was able to adapt to the type II surrounding rock, and appeared unstable in the sur⁃rounding rock of Class V. Furthermore, with the contact area declining, the support force showed obvious nature of the step period, and the instability moment was gradually ahead of time, which reflected the maladaptation to the soft surrounding rock. The research study provides evidence for the need to design the structure of gripper shoe and the geological adaptability of it.

  3. INFLUENCE OF DIFFERENT CANTILEVER EXTENSIONS AND GLASS OR POLYARAMID REINFORCEMENT FIBERS ON FRACTURE STRENGTH OF IMPLANT-SUPPORTED TEMPORARY FIXED PROSTHESIS

    Science.gov (United States)

    Colán Guzmán, Paola; de Freitas, Fernando Furtado Antunes; Ferreira, Paulo Martins; de Freitas, César Antunes; Reis, Kátia Rodrigues

    2008-01-01

    In long-term oral rehabilitation treatments, resistance of provisional crowns is a very important factor, especially in cases of an extensive edentulous distal space. The aim of this laboratorial study was to evaluate an acrylic resin cantilever-type prosthesis regarding the flexural strength of its in-balance portion as a function of its extension variation and reinforcement by two types of fibers (glass and polyaramid), considering that literature is not conclusive on this subject. Each specimen was composed by 3 total crowns at its mesial portion, each one attached to an implant component (abutment), while the distal portion (cantilever) had two crowns. Each specimen was constructed by injecting acrylic resin into a two-part silicone matrix placed on a metallic base. In each specimen, the crowns were fabricated with either acrylic resin (control group) or acrylic resin reinforced by glass (Fibrante, Angelus) or polyaramide (Kevlar 49, Du Pont) fibers. Compression load was applied on the cantilever, in a point located 7, 14 or 21 mm from the distal surface of the nearest crown with abutment, to simulate different extensions. The specimen was fixed on the metallic base and the force was applied until fracture in a universal test machine. Each one of the 9 sub-groups was composed by 10 specimens. Flexural strength means (in kgf) for the distances of 7, 14 and 21 mm were, respectively, 28.07, 8.27 and 6.39 for control group, 31.89, 9.18 and 5.16 for Kevlar 49 and 30.90, 9.31 and 6.86 for Fibrante. Data analysis ANOVA showed statistically significant difference (preinforced groups. PMID:19089201

  4. Causes and treatment of the common retaining complication for the implant supported edentulous%无牙颌种植修复固位的并发症与处理

    Institute of Scientific and Technical Information of China (English)

    宋应亮

    2013-01-01

      近年来,无牙颌患者的种植修复需求越来越多,为口腔种植学的发展提供了很大的助力,但同时存在的问题也逐渐暴露出来。本文就第四军医大学口腔医院种植科自2001年创建以来,临床上所发现的常见固位并发症原因以及处理和预防方法进行整理总结,并结合国内外先进文献报道作一综述。%In recent years, a great power has been provided to the development of oral implantology because of the more and more implant supported denture demands from the edentulous people, which also brings many problems. The purpose of this article is to review the causes and treatment of the common retaining complication from 2001 when department of implantation in hospital of stomatology of the Fourth Military Medical University founded.

  5. 热流密度对垂直地埋管群周围土壤温度的影响%Heat Transfer Analysis of Different Heat Flux on the Temperature of Vertical Pipe Group's Surrounding Soil

    Institute of Scientific and Technical Information of China (English)

    裴秉科; 周亚素; 何侃; 张根祥; 许丽洁

    2012-01-01

    Heat transfer characteristics of the group of underground pipe heat exchanger largely determine the performance of ground source heat pump system,the temperature of U-shaped vertical pipe group's surrounding soil mainly influenced by parameters such as order form,pipe depth,ground load characteristics,and soil heat transfer coefficient,etc.Through experiments to analyze the influence of different heat flux on over temperature and thermal response time of the temperature of vertical pipe group's surrounding soil,and to provide reference on the design and optimization of vertical pipe group.%地埋管群换热器的换热特性很大程度上决定了地源热泵系统的性能,其中U型埋管群周围土壤的温度特性主要受到排列形式、埋管深度、地上负荷特性以及土壤传热系数等参数的影响。通过实验来定性分析热流密度的改变对埋管群周围土壤的过余温度以及热响应时间造成的影响,为地下埋管群的设计及优化提供参考。

  6. Persistent Confusion and Controversy Surrounding Gene Patents

    Science.gov (United States)

    Guerrini, Christi J.; Majumder, Mary A.; McGuire, Amy L.

    2016-01-01

    There is persistent confusion and controversy surrounding basic issues of patent law relevant to the genomics industry. Uncertainty and conflict can lead to the adoption of inefficient practices and exposure to liability. The development of patent-specific educational resources for industry members, as well as the prompt resolution of patentability rules unsettled by recent U.S. Supreme Court decisions, are therefore urgently needed. PMID:26849516

  7. 基于广义粒子动力学的巷道围岩弹塑性分析%Elastoplastic analysis of surrounding rock masses around tunnels using general particle dynamics method

    Institute of Scientific and Technical Information of China (English)

    赵毅; 周小平; 钱七虎

    2016-01-01

    提出了广义粒子动力学数值分析方法,该方法是一种无网格数值分析方法,可以考虑关联塑性流动法则和非关联塑性流动法则对岩石材料塑性变形的影响。将广义粒子动力学数值分析方法应用于巷道围岩的弹塑性分析,确定了巷道围岩的应力场、位移场和塑性区。该数值模拟结果与有限元结果吻合较好,表明将考虑岩石材料剪胀特性的弹塑性本构理论引入到广义粒子动力学数值分析方法,不失为模拟岩石类材料弹塑性破坏的一种有效数值手段,研究结果为更好地理解岩石材料的屈服破坏过程提供重要的参考。%The novel meshless numerical method, which is known as general particle dynamics (GPD) method, is proposed. The non-associated flow law and the associated flow law can be employed to analyze the plastic deformation of the surrounding rock masses around tunnels using the GPD method. The stability of the surrounding rock masses around tunnels are also determined using the GPD method as well as the stress fields, displacement fields and plastic zone. The numerical results by the proposed method are in good agreement with the FEM results. It is proved that the GPD method is efficient to predict the elastic-plastic properties of the surrounding rock masses around tunnels.

  8. Identification of -SiC surrounded by relatable surrounding diamond medium using weak Raman surface phonons

    Indian Academy of Sciences (India)

    Mohan Kumar Kuntumalla; Harish Ojha; Vadali Venkata Satya Siva Srikanth

    2013-11-01

    It is difficult to detect -SiC using micro-Raman scattering, if it is surrounded by carbon medium. Here, -SiC is identified in the presence of a relatable surrounding diamond medium using subtle, but discernible Raman surface phonons. In this study, diamond/-SiC nanocomposite thin film system is considered in which nanosized -SiC crystallites are surrounded by a relatable nanodiamond medium that leads to the appearance of a weak Raman surface phonon band at about 855 cm-1. Change in the nature of the surrounding material structure and its volume content when relatable, will affect the resultant Raman response of -SiC phase as seen in the present case of diamond/-SiC nanocomposite thin films.

  9. Analysis on and Criteria of Stability of Surrounding Rock of Tunnel%隧道稳定性分析与设计方法讲座之二:隧道围岩稳定性分析及其判据

    Institute of Scientific and Technical Information of China (English)

    郑颖人; 丛宇

    2013-01-01

    As a summary of the past research achievements,the paper analyses three criteria for the stability of surrounding rock of tunnels and puts forward that stability safety factor with strict mechanic basis can be taken as the quantitative criteria of the stability of surrounding rock.The paper states that the safety factor of surrounding rock has shear safety factor and tensile safety factor and suggests that the safety factor of strength reserve should be adopted as the safety factor of surrounding rock.New theory and new method of stability analysis of soil tunnel are established,and the load release of surrounding rock is taken into consideration in the calculation.The primary lining is seemed as elasto-plastic material to reinforce the surrounding rock and the primary lining should have a certain safety factor to ensure the safety during tunnel construction.The secondary lining adopts elastic structure and ensures the safety of the tunnel in operation together with the combined action of surrounding rock and primary lining.The paper then provides a preliminary proposal for the classification of the surrounding rock and takes the safety factors without lining as the quantitative criteria of the self-support capability of surrounding rock of each grade.In this way,the parameters of mechanic strength of surrounding rock of each grade are obtained through inverse method,which can improve the rationality of the parameters.%作为一个讲座对以往研究成果作一综述.分析隧道围岩稳定性的3种判据,提出有严格力学依据的稳定安全系数作为围岩稳定分析的定量判据.指出围岩有剪切安全系数与拉裂安全系数,并建议采用强度储备安全系数作为围岩稳定安全系数.建立土体隧道稳定分析的新理念和新方法,计算中考虑了围岩的荷载释放,初期支护作为弹塑性材料加固围岩,并应具有一定安全系数,以确保施工安全.二次衬砌作为弹性结构,围岩、初期支护

  10. Opportunity's Surroundings on Sol 1818 (Vertical)

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this full-circle view of the rover's surroundings during the 1,818th Martian day, or sol, of Opportunity's surface mission (March 5, 2009). South is at the center; north at both ends. This view is presented as a vertical projection with geometric seam correction. North is at the top. The rover had driven 80.3 meters (263 feet) southward earlier on that sol. Tracks from the drive recede northward in this view. The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and lighter-toned bedrock.

  11. Opportunity's Surroundings on Sol 1818 (Polar)

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this full-circle view of the rover's surroundings during the 1,818th Martian day, or sol, of Opportunity's surface mission (March 5, 2009). South is at the center; north at both ends. This view is presented as a polar projection with geometric seam correction. North is at the top. The rover had driven 80.3 meters (263 feet) southward earlier on that sol. Tracks from the drive recede northward in this view. The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and lighter-toned bedrock.

  12. Clinical results of magnet-retained micro-implant-supported overdentures in edentulous jaws%微型种植体联合磁性附着体修复老年无牙颌的疗效评价

    Institute of Scientific and Technical Information of China (English)

    冯培明; 牛光良

    2015-01-01

    目的:评价微型种植体联合磁性附着体修复老年无牙颌患者的临床效果。方法:选自2012年5月至12月来自北京市中西医结合医院口腔科老年无牙颌患者15例,其中男性10例,女性5例,年龄68-83岁,平均年龄70.2岁,共植入微型种植体38颗。所有病例于种植体负重后3个月、9个月进行患者满意度调查,采用视觉模拟评分法(VAS),评价义齿舒适度、义齿稳定性、语言能力、义齿清洁性的满意度。结果:在观察期内38颗微型种植体中有2颗种植体脱落,其余36颗种植体均获得了良好骨结合。种植体负重后3个月、9个月分别与种植体负重之前相比,义齿舒适度、义齿稳定性、语言能力VAS评分经SPSS 17.0进行配对t检验均有差异(P<0.01),义齿清洁性与术前相比差异无统计学意义(P>0.05)。结论:使用微型种植体联合磁性附着体在老年无牙颌患者的应用中效果明显,值得临床推广使用。%Objective:To evaluate clinical results of magnet-retained micro-implant-supported restorations of edentulous jaws.Methods:A total of 38 micro implants were placed in 15 patients from May 2012 to December 2012, including 10 males and 5 females,aged 68-83 years old. The data of visual analogue scale (VAS) of denture satisfaction at the three months and nine months follow-up after implant loading was recorded.Results:within the period of observation, two of 38 implants failed and the remaining 36 implants demonstrated good osseointegration. At the three months and nine months follow-up, the VAS results of denture comfort, stability, speaking function were significantly improved (P<0.01) analyzed by using paired t-test (SPSS 17.0 software package).Conclusion:The use of magnet-retained micro-implant-supported overdentures in edentulous jaws is worthy of clinical use.

  13. Retrospective study of Camlog implant-supporting fixed and removable prostheses in edentulous patients%Camlog种植体支持固定和活动修复无牙颌10年临床研究

    Institute of Scientific and Technical Information of China (English)

    项立新; 熊亚茸; Susanne Heberer; Semper Wiebke; Katja Nelson

    2011-01-01

    Objective To evaluate the fixed and removable Camlog implant- supported prostheses in fully edentulous patients within a functional period. Methods One hundred and forty two patients (57 males and 85 females) with an average age of 61.3 years were treated in Department of Oral- and Maxillofacial Surgery, Charite Hospital from 1995 to 2006. A total of 910 Camlog implant were placed in the edentulous maxilla, mandible or both jaws to allow a prosthetic rehabilitation with fixed (380 implants, 41 .87%) or removable (530 implants, 58.13%) implant- retained prostheses. The survivalrate of the implants was evaluated according to gender, implant location and type ofprostheses. Results Seventeen patients lost a total of 28 implants with a cumulative implant survival rate of 96.92%. There were no significant differences in the cumulative implant survival rate between maxilla (96.98%) and mandible (96.84%) (P >0.05). The 10- year cumulative survival rate of implants after rehabilitation for fixed restoration was 98.64% and for removable implant- retained overdenture was 99.18% (P>0.05). Conclusion This retrospective study confirms good clinical outcome of implant- supported treatment for the rehabilitation of totally edentulous patients, and also shows a successful application of Camlog implants to support two types of prosthetic rehabilitation.%目的 研究10年观察期内用Camlog种植体修复无牙颌患者的种植体生存率及影响因素.方法 1995至2006年142例无牙颌患者共910颗Camlog种植体分别种植在无牙颌的上颌或下颌.其中376颗种植体(41.32%)做固定修复,534颗种植体(58.68%)做活动修复,观察性别、种植体部位和修复类型对种植成功率的影响.结果 其中17例患者28颗种植体脱落,种植体成功率96.92%,女性患者的种植体成功率略低,但差异无统计学意义(P >0.05).累计的种植体成功率上颌骨为96.98%,略高于下颌骨96.84%,但差异无统计学意义(P

  14. Site Measurement of Surrounding Rock Pressure and Analysis of Structure Stress of Large-span Bias-pressured Shallow Tunnels%大跨浅埋偏压隧道围压实测及结构受力分析

    Institute of Scientific and Technical Information of China (English)

    江磊; 侯哲生; 吴海卫

    2015-01-01

    大跨浅埋偏压隧道由于其非对称的受力条件,易引发结构变形与开裂等突出问题,近年来越来越受工程技术界的重视。以邢汾高速公路邢台段后偏梁大跨度隧道浅埋偏压段为例,通过实测围岩压力,根据荷载结构法的基本原理,利用 ANSYS 软件对其结构受力特性进行数值分析,得到结论:实测的围岩压力分布和偏压的地形之间具有较为一致的对应性,即围岩压力受地形的影响显著;二衬总应力受轴力引起的应力影响较小,主要受弯矩引起的应力控制,整个拱圈范围内最危险的部位是在受围岩压力最大的左侧拱肩处;随着二衬厚度的变化,二衬总应力在不同的部位均发生相应变化,但变化幅度均不大。相关研究结论为后续类似大跨浅埋偏压隧道的合理设计与施工提供参考依据。%The asymmetrical stress condition of the Large-span bias-pressured shallow tunnels can cause many problems easily ,such as structural deformation and cracking .These problems have attracted more and more attentions from engi-neering and technology research field in recent years .The Houpianliang large-span bias-pressured shallow tunnel in Xing-tai section of Xingtai - Fenyang highway was taken as an example to numerically analyze the mechanical characteristics of the structure by adopting ANSYS ,according to the data of site measurement of surrounding rock pressure and the princi -ple of load structure method .The results indicate that :the actual measured surrounding rock pressure is consistent with the bias terrain ,which means the surrounding rock pressure is influenced by topography significantly ;the total stress of the second lining is mainly controlled by the stress from bending moment and is less influenced by the stress from axial force ,the weakest part within the scope of the arch ring is the left spandrel which is subject to maximum pressure ;with the change of the

  15. 爆炸荷载下不同锚固参数围岩的加速度响应分析%Acceleration response analysis of surrounding rock with different anchorage parameters subjected to explosive loads

    Institute of Scientific and Technical Information of China (English)

    杨自友; 杨本水; 顾金才; 李永池; 高光发

    2011-01-01

    If acceleration of rock mass is too large, the surrounding rock of underground cavern is not stable.By analyzing time-history curves of acceleration obtained by model test, the acceleration response characteristics of surrounding rock with different anchorage parameters in underground cavern subjected to explosive loads are studied.The forms and peak values of the time-history curves of acceleration of underground cavern's crown, floor and two sides are explained respectively.Because of the different reinforcing modes, the distinctions of the acceleration response of surrounding rock of underground cavern are compared emphatically.The results indicate that the time-history curves of the vertical acceleration of crown and the horizontal acceleration of floor right side are smooth enough; but the vibration of the time-history curves of the vertical acceleration of floor and the left side are larger than the others.The acceleration of the crown is the largest than the other positions.For the cavern of the smallest spacing of rock bolts in four underground caverns, the acceleration of its crown and two sides is smaller than the other caverns; but the acceleration of its floor is larger slightly than the others'.By means of comparing and analyzing above, reducing the spacing of the rock bolts can enhance the stabilization of underground cavern.%地下洞室岩体加速度过大易造成围岩的不稳定,通过由模型试验得到的加速度-时程曲线分析,研究了爆炸荷载作用下不同锚固参数洞室围岩的加速度响应特征.分别阐述了洞室拱顶、底板、两帮加速度时程曲线的形态及其峰值大小,重点比较了洞室围岩因锚杆加固方式的不同对爆炸产生加速度响应的差异,结果表明,拱顶垂直和右帮水平加速度-时程曲线较光滑,而底板和左帮垂直加速度-时程曲线存在较大震动;洞室拱顶加速度峰值最大;4个洞室中锚杆间距最小的洞室,其拱项、两帮加速度

  16. 宁夏某引水工程隧洞围岩变形机理分析及处理%Analysis and Treatment of Deformation Mechanism of Surrounding Rock in a Water Diversion Project in Ningxia

    Institute of Scientific and Technical Information of China (English)

    李明福; 赵文超

    2015-01-01

    This subject ,based on water diversion project in central southern Ningxia ,studies engineering properties of soft rock in soft rock tunnel and gives the scientific basis for engineering design ,construction and safety operation .In the sub-ject,some properties of weak surrounding rocks ,including the hydro-physical properties,swell-shrink property,rheological properties,mechanical properties and deformation mechanism ,have been studied by several methods of exploration ,the laboratory tests,the in-situ tests,the genetic mechanism method .From composition and existing environmen of the soft rock,it reveals the difference of the soft rock property between areas and the deformation law of the weak surrounding rock with the change of environment .It also puts forward supporting time and supporting measures of the tunnel in the layered soft surrounding rock with gentle occurrence .Due to its its strong hydrophilicity ,a series of argillaceous soft rocks of Tertiary and Cretaceous ,which are widely distributed in central and southern Ningxia area ,have the characteristics of swell-shrink ,slaking ,rheology ,time effect and sensitivity to the environment and are liable to cause the deformation fail-ure of the tunnel.In consideration of the principle of engineering safety and investment control ,this research result puts forward effective measurements that can be taken to inhibit or reduce the adverse impact on the mudstone engineering from excavation method ,protection time and supporting technology .%以宁夏中南部某引水工程为对象, 研究隧洞软岩的工程特性, 为工程设计、 施工和安全运用提供科学依据. 通过勘探、 试验、 测试和数值模拟等手段, 研究软弱围岩水理特性、 胀缩性、 流变特性、 力学特性和变形机理. 从软岩的物质组成、 赋存环境等方面揭示了其区域特性方面的差异及软弱围岩变形随环境的变化规律, 提出了平缓层状软弱围岩隧

  17. 种植支持全牙弓和分段式修复无牙颌的效果观察%Observation on the Effect of Dental Implant Supported the Whole Dental Arch and Segmented Restoration

    Institute of Scientific and Technical Information of China (English)

    范胤

    2016-01-01

    目的:对比种植支持全牙弓和分段式修复无牙颌的效果。方法以我院2015年4月~2016年5月收治的42例无牙颌患者作为研究对象,采用随机数法将患者分为两组,各21例。观察组用种植支持全牙弓治疗,对照组用分段式修复治疗。结果观察组患者治疗后的美观评价水平、维护方便程度、总体满意度高于对照组,比较差异有统计学意义(P<0.05)。结论采用种植支持全牙弓治疗无牙颌治疗效果好。%Objective To compare the effects of dental implant supported total dental arch and segmental restoration in the restoration of the jaw. Methods From April 2015 to May 2016 in our hospital 42 cases of patients with non dental jaw patients as the research object, using the random number method will be divided into two groups, each of 21 cases. The observation group was treated with dental implants, and the control group was treated with staged repair. Results In the observation group after treatment, the level of aesthetic evaluation, maintenance convenience, overall satisfaction rate was higher than the control group, the difference was significant (P<0.05). Conclusion The clinical application of dental implants in the treatment of the patients with no teeth jaw.

  18. Non-linear viscoelastic finite element analysis of the effect of the length of glass fiber posts on the biomechanical behaviour of directly restored incisors and surrounding alveolar bone.

    Science.gov (United States)

    Ferrari, Marco; Sorrentino, Roberto; Zarone, Fernando; Apicella, Davide; Aversa, Raffaella; Apicella, Antonio

    2008-07-01

    The study aimed at estimating the effect of insertion length of posts with composite restorations on stress and strain distributions in central incisors and surrounding bone. The typical, average geometries were generated in a FEA environment. Dentin was considered as an elastic orthotropic material, and periodontal ligament was coupled with nonlinear viscoelastic mechanical properties. The model was then validated with experimental data on displacement of incisors from published literature. Three post lengths were investigated in this study: root insertion of 5, 7, and 9 mm. For control, a sound incisor model was generated. Then, a tearing load of 50 N was applied to both sound tooth and simulation models. Post restorations did not seem to affect the strain distribution in bone when compared to the control. All simulated post restorations affected incisor biomechanics and reduced the root's deforming capability, while the composite crowns underwent a higher degree of deformation than the sound crown. No differences could be noticed in incisor stress and strain. As for the influence of post length, it was not shown to affect the biomechanics of restored teeth. PMID:18833761

  19. The anisotropic properties analysis of the rock mass surrounding the roadway' s in seepage and stress field%巷道围岩渗流场和应力场各向异性特征分析及应用

    Institute of Scientific and Technical Information of China (English)

    杨天鸿; 师文豪; 于庆磊; 李海洲; 郑超; 夏冬

    2012-01-01

    依托范各庄煤矿12号煤层底板的砂岩巷道工程实际,应用岩体结构面非接触测量(Sha-peMetriX3D)系统,对巷道开挖面进行岩体结构面数字摄影测量及识别,得到岩体结构面的几何分布参数;在此基础上,利用Mont-Carlo方法生成裂隙网络,分别利用离散介质渗流方法和几何损伤理论计算岩体的渗透张量和弹性张量,研究了岩体力学参数各向异性和尺度效应;最后,建立了平面应变情况下的巷道围岩各向异性渗流力学模型,采用COMSOL Multiphysics多物理场分析软件,计算得到了可以考虑节理分布特征的巷道围岩应力场和渗流场,并讨论了岩体力学性质主方向对围岩应力场、渗流场及损伤区的影响。研究表明,岩体的各向异性对数值模拟结果影响显著,等效连续介质的各向异性模型能考虑岩体结构面的影响,更符合工程实际。%Depending on the sandstone roadway on the floor of No. 12 coal seam in Fangezhuang Coal Mine,a 3D con- tact-free measuring system, named as ShapeMetriX3D, was employed to capture discontinuities on the face of the road- way and obtain statistical parameters for each set of discontinuities. And then, fracture network was generated by Mont- Carlo method. Permeability tensor of rock mass was calculated by the discrete medium seepage method, and the elastic- ity tensor of rock mass was obtained by geometrical damage theory. Then, scale effect and anisotropic behaviors of rock mass were studied. Finally, an anisotropic percolation mechanics model of surrounding rock mass of the roadway was built under plane strain condition. Using COMSOL multiphysics code, the stress field and seepage field surrounding the roadway were obtained, which can take into account the influence of orientation of discontinuities. Furthermore, the in- fluences of principal direction of rock mass properties on stress, seepage and damage zone were discussed. The results show that the

  20. 环鄱阳湖地区原生态舞龙文化的特点探析%Analysis of the Features of the Original Eco-cultural Dragon Dancing in the Regions Surrounding Poyang Lake

    Institute of Scientific and Technical Information of China (English)

    王俊奇

    2011-01-01

    This paper adopts literatures and logics to make a study on the cultural features of eco-dragon dancing in the regions surrounding Poyang Lake.It concludes that the faith and worship are present in all aspects of it,so are the inhabitants' faith and sincerity in lives.It is performed by emulating all kinds of animals which they worship and diverse in forms,such as jumping dragon and straw dragon,which they perform on the sunning ground or on the path of the rice fields for the purpose of praying for the good harvest.This kind of dragon dancing,full of humanity,is not skill showing,but rather the epitome of the farming culture which exists for hundreds of years.%采用文献法,逻辑学方法,对环鄱阳湖地区原生态舞龙的文化特点进行研究。分析认为:鄱阳湖地区的舞龙处处体现着信仰和崇拜,体现着一方人民对生活的真诚和感动。环鄱阳湖舞龙多种动物样态,反映的是各种崇拜。他们有的在晒谷场舞跳脚龙,有的在田埂上狂舞草龙,都是祈求五谷丰登,这种充满人性的舞龙不同于一般单纯炫技,而是千百年农耕文化的缩影。

  1. Characterizing the Microenvironment Surrounding Phosphorylated Protein Sites

    Institute of Scientific and Technical Information of China (English)

    Shi-Cai Fan; Xue-Gong Zhang

    2005-01-01

    Protein phosphorylation plays an important role in various cellular processes. Due to its high complexity, the mechanism needs to be further studied. In the last few years, many methods have been contributed to this field, but almost all of them investigated the mechanism based on protein sequences around protein sites. In this study, we implement an exploration by characterizing the microenvironment surrounding phosphorylated protein sites with a modified shell model, and obtain some significant properties by the rank-sum test, such as the lack of some classes of residues, atoms, and secondary structures. Furthermore, we find that the depletion of some properties affects protein phosphorylation remarkably. Our results suggest that it is a meaningful direction to explore the mechanism of protein phosphorylation from microenvironment and we expect further findings along with the increasing size of phosphorylation and protein structure data.

  2. A nonthermal radio halo surrounding M82

    International Nuclear Information System (INIS)

    Radio maps at several frequencies are presented which reveal an extended halo of nonthermal emission surrounding the starburst galaxy M82. The origin of this halo is probably synchrotron radiation from relativistic electrons originally produced in SNR, swept out of the disk by the extensive wind associated with the galaxy. The halo appears to be asymmetrical, with an enhancement occurring about 1 arcmin to the south, and on a larger scale there is excess emission to the north. Possible causes of this effect are addressed. The spectral index measured using data at 6, 20, 49, and 90 cm is about -0.4 + or - 0.1 in the nucleus, steepening to about -1.0 in the halo. A simple model is invoked which involves outward convection of relativistic particles with electron energy losses by inverse Compton scattering against IR photons and adiabatic expansion. 35 refs

  3. Opportunity's Surroundings on Sol 1798 (Polar)

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this 180-degree view of the rover's surroundings during the 1,798th Martian day, or sol, of Opportunity's surface mission (Feb. 13, 2009). North is on top. This view is presented as a polar projection with geometric seam correction. The rover had driven 111 meters (364 feet) southward on the preceding sol. Tracks from that drive recede northward in this view. For scale, the distance between the parallel wheel tracks is about 1 meter (about 40 inches). The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and lighter-toned bedrock.

  4. Opportunity's Surroundings on Sol 1687 (Polar)

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this 360-degree view of the rover's surroundings on the 1,687th Martian day, or sol, of its surface mission (Oct. 22, 2008). Opportunity had driven 133 meters (436 feet) that sol, crossing sand ripples up to about 10 centimeters (4 inches) tall. The tracks visible in the foreground are in the east-northeast direction. Opportunity's position on Sol 1687 was about 300 meters southwest of Victoria Crater. The rover was beginning a long trek toward a much larger crater, Endeavour, about 12 kilometers (7 miles) to the southeast. This view is presented as a polar projection with geometric seam correction.

  5. Opportunity's Surroundings After Sol 1820 Drive (Polar)

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this full-circle view of the rover's surroundings during the 1,820th to 1,822nd Martian days, or sols, of Opportunity's surface mission (March 7 to 9, 2009). This view is presented as a polar projection with geometric seam correction. North is at the top. The rover had driven 20.6 meters toward the northwest on Sol 1820 before beginning to take the frames in this view. Tracks from that drive recede southwestward. For scale, the distance between the parallel wheel tracks is about 1 meter (about 40 inches). The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and small exposures of lighter-toned bedrock.

  6. Opportunity's Surroundings on Sol 1687 (Vertical)

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this 360-degree view of the rover's surroundings on the 1,687th Martian day, or sol, of its surface mission (Oct. 22, 2008). Opportunity had driven 133 meters (436 feet) that sol, crossing sand ripples up to about 10 centimeters (4 inches) tall. The tracks visible in the foreground are in the east-northeast direction. Opportunity's position on Sol 1687 was about 300 meters southwest of Victoria Crater. The rover was beginning a long trek toward a much larger crater, Endeavour, about 12 kilometers (7 miles) to the southeast. This view is presented as a vertical projection with geometric seam correction.

  7. Opportunity's Surroundings on Sol 1798 (Vertical)

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this 180-degree view of the rover's surroundings during the 1,798th Martian day, or sol, of Opportunity's surface mission (Feb. 13, 2009). North is on top. This view is presented as a vertical projection with geometric seam correction. The rover had driven 111 meters (364 feet) southward on the preceding sol. Tracks from that drive recede northward in this view. For scale, the distance between the parallel wheel tracks is about 1 meter (about 40 inches). The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and lighter-toned bedrock.

  8. Opportunity's Surroundings After Sol 1820 Drive

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this full-circle view of the rover's surroundings during the 1,820th to 1,822nd Martian days, or sols, of Opportunity's surface mission (March 7 to 9, 2009). South is at the center; north at both ends. The rover had driven 20.6 meters toward the northwest on Sol 1820 before beginning to take the frames in this view. Tracks from that drive recede southwestward. For scale, the distance between the parallel wheel tracks is about 1 meter (about 40 inches). The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and small exposures of lighter-toned bedrock. This view is presented as a cylindrical projection with geometric seam correction.

  9. Opportunity's Surroundings After Sol 1820 Drive (Vertical)

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this full-circle view of the rover's surroundings during the 1,820th to 1,822nd Martian days, or sols, of Opportunity's surface mission (March 7 to 9, 2009). This view is presented as a vertical projection with geometric seam correction. North is at the top. The rover had driven 20.6 meters toward the northwest on Sol 1820 before beginning to take the frames in this view. Tracks from that drive recede southwestward. For scale, the distance between the parallel wheel tracks is about 1 meter (about 40 inches). The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and small exposures of lighter-toned bedrock.

  10. Exploiting Surrounding Text for Retrieving Web Images

    Directory of Open Access Journals (Sweden)

    S. A. Noah

    2008-01-01

    Full Text Available Web documents contain useful textual information that can be exploited for describing images. Research had been focused on representing images by means of its content (low level description such as color, shape and texture, little research had been directed to exploiting such textual information. The aim of this research was to systematically exploit the textual content of HTML documents for automatically indexing and ranking of images embedded in web documents. A heuristic approach for locating and assigning weight surrounding web images and a modified tf.idf weighting scheme was proposed. Precision-recall measures of evaluation had been conducted for ten queries and promising results had been achieved. The proposed approach showed slightly better precision measure as compared to a popular search engine with an average of 0.63 and 0.55 relative precision measures respectively.

  11. 真空预压法加固软土地基的影响区分析%Analysis of Affected Surrounding Area of Soft Soils Improv ed with Vacuum Preloading Technique

    Institute of Scientific and Technical Information of China (English)

    于志强; 朱耀庭; 喻志发

    2001-01-01

    Based on the results of borehole testing,the effect of vacuum preloading technique when being employed to improve soft soils upon the property index of the surrounding soils is analyzed herein. The observed data of deformation of soils outside the improved areas by vacuum preloading in dif ferent geological conditions are employed to analyze the horizontal deformation of soil mass within a certain range of soils and surface settlement in the improv ed areas as well as fectors which may have an influence upon the deformation and settlement. An empirical method is presented herein to estimate the possible d e formation in the affected areas of soils to be improved by using the theoretically calculated maximum settlement S∞. When there are structures and buildings outside the improved areas, there should be a safe buffer zone between the borde r of the improved areas and the structures and buildings in question or precauti ons should be taken to prevent over-deformation.%本文根据钻孔试验结果,分析了真空预压法加固软土地基时对 周围土体土性指标的影响,利用不同地质条件下真空预压加固区外变形观测资料,分析了加 固区一定范围内土体水平位移、地表沉降大小及影响因素,提出利用理论计算最大沉降量 S∞估算加固影响区可能发生变形的经验方法,在加固区外有构筑物时,预压边线与构 筑物间应预留一定的安全距离或应采取防止过大变形措施。

  12. Preliminary study on tactile function of implant-supported single crowns%种植体支持单冠被动触觉敏感度及影响因素初探

    Institute of Scientific and Technical Information of China (English)

    李娜; 谢秋菲; 林野

    2013-01-01

    Objective To measure passive tactile threshold of implant-supported single crowns (ISSC) in six orthogonal orientations,to analyze impact factors,and to guide the occlusal adjustment in a personalized manner.Methods The passive tactile thresholds of 24 implant-supported single crowns (5 maxillary anterior teeth,7 maxillary posterior teeth and 12 mandibular posterior teeth) from 19 ISSC patients (8 men and 11 women,from 25 years old to 56 years old) were measured in six orthogonal orientations (four horizontal orientations of labial or buccal,lingual,mesial and distal,and two axial orientations of apical and coronal) using a digital test system for tactile function of teeth.SPSS 19.0 for windows was used to analyze impact factors,using double-sided test,with a significance level of 0.05.Paired-samples t test was used to test the difference between implant-supported single crowns and the controlled natural teeth,and between different time points.One-way ANOVA was used to test the difference between different orientations,maxilla-mandibular anterior-posterior,and men-women.Results The passive tactile thresholds of ISSC and control teeth were (1282 ± 709) and (40 ± 40) mN respectively.The difference was of statistical significance (P < 0.001).The passive tactile thresholds of buccal-lingual,mesial-distal and axial of ISSC were (1334 ± 696),(1102 ± 605) and (1412 ± 791) mN respectively,of which,the difference between mesial-distal and axial was of statistical significance (P < 0.05).The passive tactile thresholds of ISSC of maxillary anterior teeth,posterior teeth and mandibular posterior teeth were (1003 ± 616),(1302 ± 620) and (1386 ± 769) mN respectively,of which,the difference between maxillary anterior teeth and posterior teeth was of statistical significance (P < 0.05).The passive tactile thresholds of ISSC of men and women were (1751 ±784) and (946 ± 393) mN respectively,the difference was of statistical significance (P < 0.001).The passive

  13. Virtual reproducing system for 5.1 channel surround sound

    Institute of Scientific and Technical Information of China (English)

    XIE Bosun; SHI Yong; XIE Zhiwen; GUAN Shanqun

    2005-01-01

    An improved virtual reproducing system for 5.1 channel surround sound and signal processing algorithm of the system are proposed. Firstly, by analyzing the sound field of virtual reproducing systems for 5.1 ch surround sound, it is proved that there are some defects in current systems, including narrow listening area, sound image direction distortion, timbre change in reproduction etc. Then from theoretical analysis, it is proposed that, by decreasing the separated angle between reproducing loudspeaker pair to ±15° and using signal processing algorithm with timbre equalization, the improved system can get rid of the defects of current systems. Additionally, the signal processing algorithm of improved system is also simple. The results of psychoacoustic experiment verify theoretical analysis, and show that improved system is able to recreate sound image in half of horizontal plane (about ±90°) in the front. Finally, the system and its arrangement of loudspeakers are suitable to be used in TV sets or multimedia computers.

  14. Opportunity's Surroundings on Sol 1687 (Stereo)

    Science.gov (United States)

    2009-01-01

    [figure removed for brevity, see original site] Left-eye view of a color stereo pair for PIA11739 [figure removed for brevity, see original site] Right-eye view of a color stereo pair for PIA11739 NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this stereo, 360-degree view of the rover's surroundings on the 1,687th Martian day, or sol, of its surface mission (Oct. 22, 2008). The view appears three-dimensional when viewed through red-blue glasses. Opportunity had driven 133 meters (436 feet) that sol, crossing sand ripples up to about 10 centimeters (4 inches) tall. The tracks visible in the foreground are in the east-northeast direction. Opportunity's position on Sol 1687 was about 300 meters southwest of Victoria Crater. The rover was beginning a long trek toward a much larger crater, Endeavour, about 12 kilometers (7 miles) to the southeast. This panorama combines right-eye and left-eye views presented as cylindrical-perspective projections with geometric seam correction.

  15. Opportunity's Surroundings on Sol 1818 (Stereo)

    Science.gov (United States)

    2009-01-01

    [figure removed for brevity, see original site] Left-eye view of a color stereo pair for PIA11846 [figure removed for brevity, see original site] Right-eye view of a color stereo pair for PIA11846 NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this full-circle view of the rover's surroundings during the 1,818th Martian day, or sol, of Opportunity's surface mission (March 5, 2009). South is at the center; north at both ends. This view combines images from the left-eye and right-eye sides of the navigation camera. It appears three-dimensional when viewed through red-blue glasses with the red lens on the left. The rover had driven 80.3 meters (263 feet) southward earlier on that sol. Tracks from the drive recede northward in this view. The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and lighter-toned bedrock. This view is presented as a cylindrical-perspective projection with geometric seam correction.

  16. Opportunity's Surroundings on Sol 1798 (Stereo)

    Science.gov (United States)

    2009-01-01

    [figure removed for brevity, see original site] Left-eye view of a color stereo pair for PIA11850 [figure removed for brevity, see original site] Right-eye view of a color stereo pair for PIA11850 NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this stereo 180-degree view of the rover's surroundings during the 1,798th Martian day, or sol, of Opportunity's surface mission (Feb. 13, 2009). North is on top. This view combines images from the left-eye and right-eye sides of the navigation camera. It appears three-dimensional when viewed through red-blue glasses with the red lens on the left. The rover had driven 111 meters (364 feet) southward on the preceding sol. Tracks from that drive recede northward in this view. For scale, the distance between the parallel wheel tracks is about 1 meter (about 40 inches). The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and lighter-toned bedrock. This view is presented as a cylindrical-perspective projection with geometric seam correction.

  17. Opportunity's Surroundings After Sol 1820 Drive (Stereo)

    Science.gov (United States)

    2009-01-01

    [figure removed for brevity, see original site] Left-eye view of a color stereo pair for PIA11841 [figure removed for brevity, see original site] Right-eye view of a color stereo pair for PIA11841 NASA's Mars Exploration Rover Opportunity used its navigation camera to take the images combined into this full-circle view of the rover's surroundings during the 1,820th to 1,822nd Martian days, or sols, of Opportunity's surface mission (March 7 to 9, 2009). This view combines images from the left-eye and right-eye sides of the navigation camera. It appears three-dimensional when viewed through red-blue glasses with the red lens on the left. The rover had driven 20.6 meters toward the northwest on Sol 1820 before beginning to take the frames in this view. Tracks from that drive recede southwestward. For scale, the distance between the parallel wheel tracks is about 1 meter (about 40 inches). The terrain in this portion of Mars' Meridiani Planum region includes dark-toned sand ripples and small exposures of lighter-toned bedrock. This view is presented as a cylindrical-perspective projection with geometric seam correction.

  18. The lithosphere-asthenosphere Italy and surroundings

    CERN Document Server

    Panza, G F; Chimera, G; Pontevivo, A; Raykova, R

    2003-01-01

    The velocity-depth distribution of the lithosphere-asthenosphere in the Italian region and surroundings is imaged, with a lateral resolution of about 100 km, by surface wave velocity tomography and non-linear inversion. Maps of the Moho depth, of the thickness of the lithosphere and of the shear-wave velocities, down to depths of 200 km and more, are constructed. A mantle wedge, identified in the uppermost mantle along the Apennines and the Calabrian Arc, underlies the principal recent volcanoes, and partial melting can be relevant in this part of the uppermost mantle. In Calabria a lithospheric doubling is seen, in connection with the subduction of the Ionian lithosphere. The asthenosphere is shallow in the Southern Tyrrhenian Sea. High velocity bodies, cutting the asthenosphere, outline the Adria-lonian subduction in the Tyrrhenian Sea and the deep-reaching lithospheric root in the Western Alps. Less deep lithospheric roots are seen in the Central Apennines. The lithosphere-asthenosphere properties delineat...

  19. The lithosphere-asthenosphere: Italy and surroundings

    Institute of Scientific and Technical Information of China (English)

    GiulianoF.Panza; AntonellaPontevivo; GiordanoChimera; RenetaRaykova; AbdelkrimAoudia

    2003-01-01

    The velocity-depth distribution of the lithosphere-asthenosphere in the Italian region and surroundings is imaged, with a lateral resolution of about 100 km, by sur-face wave velocity tomography and non-linear inversion.Maps of the Moho depth, of the thickness of the lithos-phere and of the shear-wave velocities, down to depths of 200 km and more, are constructed. A mantle wedge, iden-tified in the uppermost mantle along the Apennines and the Calabrian Arc, underlies the prmctpat recent votca-noes, and partial melting can be relevant in this part of the uppermost mantle. In Calabria, a lithospheric dou-bling is seen, in connection with the subduction of the Ionian lithosphere. The asthenosphere is shallow in the Southern Tyrrhenian Sea. High velocity bodies, cutting the asthenosphere, outline the Adria-lonian subduction in the Tyrrhenian Sea and the deep-reaching lithospheric root in the Western Alps. Less deep lithospheric roots are seen in the Central Apennines. The lithosphere-asthenos-phere properties delineate a differentiation between the northern and the southern sectors of the Adriatic Sea,likely attesting the fragmentation of Adria.

  20. Preliminary design of surrounding heliostat fields

    Energy Technology Data Exchange (ETDEWEB)

    Collado, Francisco J. [Zaragoza University, Dpto. de Ingenieria Mecanica, CPS-B, Maria de Luna 3, 50018 Zaragoza (Spain)

    2009-05-15

    Recently, the author has shown elsewhere a simplified model that allows quick evaluations of the annual overall energy collected by a surrounding heliostat field. This model is the combination of an analytical flux density function produced by a heliostat, developed by the own author, and an optimized mirror density distribution developed by University of Houston for the Solar One Project. As main conclusion of this previous work, it was recognized that such pseudo-continuous simplified model should not substitute much more accurate discrete evaluations, which manage thousands of individual heliostat coordinates. Here in this work, the difficulty of generating a preliminary discrete layout of a large number of heliostats is addressed. The main novelty is the direct definition of thousands of heliostat coordinates through basically two parameters i.e. a simplified blocking factor and an additional security distance. Such procedure, which was formerly theoretically suggested by the author, is put into practice here, showing examples and commenting their problems and advantages. Getting a previous set of thousands of heliostat coordinates would be a major first step in the complex process of designing solar power tower (SPT). (author)

  1. The Interstellar Medium Surrounding the Sun

    Science.gov (United States)

    Frisch, Priscilla C.; Redfield, Seth; Slavin, Jonathan D.

    2011-09-01

    The Solar System is embedded in a flow of low-density, warm, and partially ionized interstellar material that has been sampled directly by in situ measurements of interstellar neutral gas and dust in the heliosphere. Absorption line data reveal that this interstellar gas is part of a larger cluster of local interstellar clouds, which is spatially and kinematically divided into additional small-scale structures indicating ongoing interactions. An origin for the clouds that is related to star formation in the Scorpius-Centaurus OB association is suggested by the dynamic characteristics of the flow. Variable depletions observed within the local interstellar medium (ISM) suggest an inhomogeneous Galactic environment, with shocks that destroy grains in some regions. Although photoionization models of the circumheliospheric ISM do an excellent job of reproducing the observed properties of the surrounding ISM, the unknown characteristics of the very low-density hot plasma filling the Local Bubble introduces uncertainty about the source of ionization and nature of cloud boundaries. Recent observations of small cold clouds provide new insight into the processes affecting the local ISM. A fuller understanding of the local ISM can provide insights into the past and future Galactic environment of the Sun, and deeper knowledge of the astrospheres of nearby stars.

  2. Locator附着体和球帽附着体在种植覆盖义齿中的临床修复效果比较%Clinical effects of Locator attachment and ball-cap attachment on implant-supported overdentures

    Institute of Scientific and Technical Information of China (English)

    武红艳; 王仁飞; 朱琰; 顾亚军

    2016-01-01

    目的:探讨球帽基台和locator基台在种植体覆盖义齿( IODs)修复中临床效果的比较。方法选择单颌牙根嵴严重萎缩全口无牙颌患者27例,共计54枚种植体,其中球基台附着体26枚,locator基台附着体28枚。上部修复完成后6个月复诊并每年随访,从种植体、牙周黏膜、附着体等方面进行复查,统计其总的并发症发生率并对患者的满意度进行评价。结果两种基台支持式覆盖义齿患者的满意度明显高于普通全口义齿(P0.05)。 locator基台支持的覆盖义齿并发症的发生率仅为14.28%,球帽种植覆盖义齿总的并发症发生率为38.46%。结论 locator基台和球帽基台支持式全口义齿均优于常规全口义齿,locator基台产生的并发症更少。%Objective To compare the clinical effects of locator attachment and ball-cap attachment on implant-supported overden-tures. Methods 27 cases of mandibular edentulous were collected for 54 implants, which included 26 ball attachments and 28 locator attachments. All of the patients were followed up for further evaluation after 6 months’ functional loading and continued yearly. Both the incidence rate of prosthetic complications ( including overdentures, implant failures, attachment fractures) and the score of patient sat-isfaction were recorded for statistical analysis during our reexamination. Results The satisfaction of patients with an overdenture sup-ported by attachments was significantly improved(P0. 05), but the complication rate in the group treated with locator attach-ment was 14. 28%, while in the ball attachment group it reached 38. 46%. Conclusion Overdenture supported by locator attachment or ball attachment is more satisfying than the previous complete denture. Furthermore, with regard to the rate of prosthodontic compli-cations, the clinical results of locator attachment was superior to the ball attachment.

  3. THEORETICAL AND METHODOLOGICAL BASIS OF "DEVELOPING SURROUNDING" DEFINITION

    Directory of Open Access Journals (Sweden)

    Shalenkova M. K.

    2014-09-01

    Full Text Available The basis definition of "developing surrounding" is presented. The most important qualities, components and conditions of creation of the developing surrounding, such as material and technical, social and hygienic, ergonomic, psychological and pedagogical is considered. A great value of the developing surrounding in the educational institutions is revealed

  4. Finite element analysis on stress distribution of maxillary implant-retained overdentures depending on the Bar attachment design and palatal coverage

    Science.gov (United States)

    2016-01-01

    PURPOSE The purpose of this study was to determine the effect of anchorage systems and palatal coverage of denture base on load transfer in maxillary implant-retained overdenture. MATERIALS AND METHODS Maxillary implant-retained overdentures with 4 implants placed in the anterior region of edentulous maxilla were converted into a 3-D numerical model, and stress distribution patterns in implant supporting bone in the case of unilateral vertical loading on maxillary right first molar were compared with each other depending on various types of anchorage system and palatal coverage extent of denture base using three-dimensional finite element analysis. RESULTS In all experimental models, the highest stress was concentrated on the most distal implant and implant supporting bone on loaded side. The stress at the most distal implant-supporting bone was concentrated on the cortical bone. In all anchorage system without palatal coverage of denture base, higher stresses were concentrated on the most distal implant and implant supporting bone on loaded side. CONCLUSION It could be suggested that when making maxillary implant retained overdenture, using Hader bar instead of milled bar and full palatal coverage rather than partial palatal coverage are more beneficial in distributing the stress that is applied on implant supporting bone. PMID:27141251

  5. 后牙区单牙种植修复后边缘骨吸收的回顾性研究%Retrospective Study of Marginal Bone Loss about Single Tooth Implant-supported Restorations in the Posterior Region.

    Institute of Scientific and Technical Information of China (English)

    李广; 宋应亮; 李德华; 赵铱民; 周炜

    2011-01-01

    Objective: To analyze the relationship between marginal bone loss around implants placed in posterior region and age, length of implants, diameter of implants, location of implants, crown-to-root ratio of implantsupported restorations and the history of peri-implantitis.Methods: A prospective cohort study design was used.Results: The cohort was composed of 188 patients who were followed about 37.4 (SD= 8.9; range 12 to 48) months.The mean age was 43.6 (SD=5.6; range 18 to 75).The mean length of implants was 10.4 months.The cumulative success rate was 100%.The mean CRR was 1.06 (SD=0.22; range 0.69 to 1.86).The mean CRR of those patients who are beyond 60 years old was higher than the others (P<0.001).The same result was found between different lengths of implants (P< 0.001).However, patient' s age, length of implants, diameter of implants, location of implants and CRR of implant-supported restorations did not appear to affect MBL around implants.Significant difference were found regarding MBL in first time interval (P<0.001) and the history of periimplantitis (P=0.002).Conclusion: The CRR of old patients (>60) was significant different from young patients (<60).There was no relationship between MBL and other factors which had been analyzed in this study except the history of peri-implantitis.%目的:分析后牙区单牙种植修复患者年龄、种植体长度、直径、位置、种植修复体CRR和种植体周围炎症病史等因素与种植体周围MBL之间的关系.方法:回顾性队列研究.结果:188名患者的平均年龄43.6±5.6岁,种植体平均长度10.4 mm,随访时间12~48个月.所有种植体在回访期间均未出现松动、脱落、折断等情况,累计生存率达100%.种植修复体平均CRR为1.06±0.22,年龄大于60岁的患者CRR值较高(P<0.001);不同长度种植体的CRR分布间存在统计学差异(P<0.001);种植修复后第1年内的MBL值与其他时间段的测量结果相比较高(P<0.001);不同时

  6. Clinical observation of screw and cement-retained implant-supported restoration of fixed bridges%2种固位方式在种植体支持固定桥中的应用比较

    Institute of Scientific and Technical Information of China (English)

    宋涛; 徐培成; 李煜

    2011-01-01

    PURPOSE: To compare the prosthetic outcome of screw- and cement-retained implant-supported restorations of the fixed bridges. METHODS: A total of 185 Straumann implants were placed in the alveolar bone of 68 partially edentulous patients from Jan. 2006 to Dec. 2007. All of them were 2 to 6 units of combination crowns with Straumann system. Then they were followed up for 3 years. In each group, the retention, influence on hard and soft tissues, passive fitting and rupture strength of the ceramic layer were evaluated. The data was analyzed with SPSS12.0 software package. RESULTS: There were more advantages of retention and the rupture strength of the ceramic layer in the cement-retained group, while there was less influence on the hard and soft tissues, and more facility of maintenance and reparation in the screwed-retained group. The difference between the two groups was statistically not significant (P>0.05). CONCLUSIONS; The clinical outcomes of implant restorations are satisfactory, either screw-retained or cement-retained. Cement retention is used in 2 to 3 unit combination crowns, while screw retention is more suitable for complicated cases.%目的:评价螺丝固位和黏结固位在种植体联合修复中的临床应用效果.方法:2006年1月-2007年12月间,共为66例患者植入185颗Straumann种植体,均为2-6颗的联冠修复.随访3a,从固位效果、对软硬组织的影响、被动就位及瓷层的抗折能力等临床指标对2种修复方式进行评价.采用SPSS12.0软件包对数据进行统计学分析.结果:黏结固位方式在固位效果及瓷层的抗折能力上较好,螺丝固位在软组织的影响和维护修理的便利性上效果较好,但均无统计学差异.结论:在种植固定桥修复中,螺丝固位与黏结固位均为有效可靠的修复方式.黏结固位在2~3个单位的简单联冠修复上占有优势,而螺丝固位更适合于复杂病例的修复.

  7. Satisfaction Analysis of the New Rural Cooperative Medical System in the Surrounding Rural Areas of Nanning%南宁市周边农村新型农村合作医疗制度满意度分析

    Institute of Scientific and Technical Information of China (English)

    郑敦林; 黄菊铃; 朱平华

    2013-01-01

    目的:分析南宁市周边参合农民对新型农村合作医疗制度的满意度情况及影响因素,为完善新农合政策提供建议.方法:采取分层随机抽样的方法,以110户农村常住家庭为对象,通过问卷调查与访谈获取信息.结果:调查对象参合率为98.2%,对新农合总体印象满意率为89.8%.影响满意度的主要因素包括政策宣传知晓程度、报销比例、报销范围、报销手续、定点医疗机构服务水平与就医环境等.结论:新农合制度的宣传方式还需多样化、简易化;逐步提高住院报销比例,扩大报销范围,简化报销手续;改善基层定点医疗机构的服务状况与就医环境,培养专业的管理人才.%Obiective:Analysis of Nanning City farmers to new rural cooperative medical system satisfaction and influencing factors,for new rural cooperative medical advice.Methods:The research adopted stratified random sampling and survey 110 households in the rural resident families through a questionnaire survey and interviews with a combination of access to information.Results:Survey participation rate is 98.2%,on the new overall satisfaction 89.8%.Influence farmer participation satisfaction are the main factors including policy advocacy and awareness,the proportion of claims,the scope of claims,claims handling,designated medical institutions and the level of service of medical treatment environment in five aspects.Conclusion:The new rural cooperative medical system has yet to be further improved:Propaganda way diversification,simplification; Gradually improve the reimbursement ratio,expand the scope of reimbursement,simplify the procedures for reimbursement; Improvement of grassroots medical institutions and thelevel of service of medical treatment environment ; cultivating the professional management talents of the social medical insurance.

  8. 种植磁性附着体支持的赝附体修复单侧无牙上颌骨缺损的临床疗效观察%Clinical application of implant-supported obturator using magnetic attachments to repair the unilateral edentulous maxillary defect

    Institute of Scientific and Technical Information of China (English)

    李景辉; 杨瑛; 张方明

    2014-01-01

    目的:观察种植磁性附着体支持的赝附体修复单侧无牙上颌骨缺损的临床效果,并与传统赝附体进行对比,以期为单侧无牙上颌骨缺损的临床治疗提供参考。方法选取单侧无牙上颌骨缺损的患者20例,随机分为两组,种植磁性附着体赝附体组10例,传统赝附体组10例,比较两组患者的治疗效果。结果种植磁性附着体赝附体组固位力高于传统赝附体组,差异具有统计学意义( P ﹤0.05)。种植磁性附着体赝附体组咀嚼效率明显高于传统赝附体组,差异具有统计学意义( P ﹤0.05)。结论种植磁性附着体支持的赝附体是一种可靠、有效的修复单侧无牙上颌骨缺损的治疗方法,固位力和咀嚼效率均高于传统赝附体治疗,值得临床推广。%Objective To observe the clinical effects of implant-supported obturator using magnetic attachments to repair the unilateral edentulous maxillary defect. The results were compared with the traditional obsturator in order to provide reference for the clinical treatment of uni_lateral edentulous maxillary defect. Methods Twenty patients with unilateral edentulous maxillary defect were randomly divided into two groups. Ten patients in implant-supported obturator group using magnetic attachments,and another 10 in the conventional obturator group. The retention force and biting efficiency were compared between these two groups. Results The implant -supported obturator group exhibited significantly stronger retention force and higher biting efficiency than conventional obsturator group,with statistically significant difference( P ﹤0. 05). Con-clusion The implant-supported obturator using magnetic attachments is a reliable and effective method to repair the unilateral edentulous maxil_lary defect and needs to be promoted.

  9. 种植体支持球帽附着体固位下颌覆盖全口义齿的临床应用%Clinical application of implant-supported complete overdenture retained with stud attachment for edentulous mandibles

    Institute of Scientific and Technical Information of China (English)

    王林虎; 石咏梅; 郭家平; 董青山

    2011-01-01

    目的:评价种植体支持球帽附着体固位的下颌覆盖全口义齿临床应用效果.方法:随机选择15例下颌无牙颌患者,每例植入2枚种植体,共植入30枚,随访观察1-12个月,从患者满意度、临床检查及种植体X线片观察修复效果.结果:种植体支持覆盖全口义齿修复下颌无牙颌,义齿固位和咀嚼功能满意率分别为100%和93.3%,义齿稳固,咀嚼功能好.12个月后复查X线片显示种植体周围无明显骨吸收.结论:种植体支持球帽附着体固位覆盖全口义齿修复临床效果良好,可作为下颌无牙颌患者首选修复方案.%Objective: To evaluate clinical effects of implant-supported complete overdentures retained with stud attachment for edentulous mandibles. Methods: Fifteen mandibular edentulous patients were randomly selected, who received implant-supported complete overdentures retained with stud attachment. Thirty implants were used and each patient was placed into 2 implants. After 12 months followed-up period, clinical effects were observed, including patient satisfaction, clinical examination and X-ray examination. Results: After the implant-supported complete overdentures were used in edentulous mandible, the satisfaction of patients in denture retention and masticatory function were 100% and 93.3%, respectively. There was no obvious bone resorption around implants through X-ray photography after 12 months. Conclusion: The implant-supported overdentures with stud attachmentcould be used as the optimal restoration for edentulous patients.

  10. TIME-DEPENDENT DEFORMATION ANALYSIS OF SURROUNDING ROCK OF LARGE-SCALE CAVERNS SUBJECT TO COMPLEX GEOSTRESS CONDITION AND ITS MECHANICAL SIMULATION%复杂地应力环境大型地下洞室围岩时效变形机制及力学模拟

    Institute of Scientific and Technical Information of China (English)

    刘会波; 肖明; 赵辰; 陈俊涛

    2013-01-01

    The time-dependent deformation mechanism of surrounding rock of large-scale underground caverns subjected to blast excavation and complex geostress condition is analyzed and a mechanical simulation method is proposed. Based on the analysis of monitored displacements and rockmass mechanics theory,it is identified that the high geostress mechanism and spatial effect of excavation damaged zone are two main affecting factors for the time-dependent behavior of surrounding rock of underground cavern in complex high geostress environment. With excavation process simulated by the stress release finite element method,time-dependent identification functions of excavation release loads and excavation damaged zones are established. Thus,a partition method for sequential excavation loads release based on the monitored curve of displacement vs. time and a deterioration model for deformation modulus on the basis of partial concept of excavation damaged zones are presented. Illustrated with engineering application to deformation analysis of large-scale underground powerhouse of Xiluodu hydropower plant,it is shown that,by coupling calculation of the excavation release load and spatial damaged zone,the simulation method is rational and effective for time-dependent behavior analysis of surrounding rock of large-scale caverns on the whole excavation process , which is of applicability and practical reference for the interpretation and control of deformation and damage effect of surrounding rock under complex geostress condition subjected to blast excavation,for optimizing the construction and supporting,and effective monitoring feedback analysis.%提出复杂地应力环境下大型地下洞室开挖围岩时效变形机制及其力学模拟方法。基于变形监测资料和岩体力学分析认为,中高地应力条件下岩体由高围压环境急剧转变为低围压、高应力差环境的力学机制和工程开挖引致围岩扰动破坏的空间效应是复杂地应力

  11. Interactions between surround suppression and interocular suppression in human vision.

    Directory of Open Access Journals (Sweden)

    Yong-Chun Cai

    Full Text Available Several types of suppression phenomena have been observed in the visual system. For example, the ability to detect a target stimulus is often impaired when the target is embedded in a high-contrast surround. This contextual modulation, known as surround suppression, was formerly thought to occur only in the periphery. Another type of suppression phenomena is interocular suppression, in which the sensitivity to a monocular target is reduced by a superimposed mask in the opposite eye. Here, we explored how the two types of suppression operating across different spatial regions interact with one another when they simultaneously exert suppressive influences on a common target presented at the fovea. In our experiments, a circular target grating presented to the fovea of one eye was suppressed interocularly by a noise pattern of the same size in the other eye. The foveal stimuli were either shown alone or surrounded by a monocular annular grating. The orientation and eye-of-origin of the surround grating were varied. We found that the detection of the foveal target subjected to interocular suppression was severely impaired by the addition of the surround grating, indicating strong surround suppression in the fovea. In contrast, when the interocular suppression was released by superimposing a binocular fusion ring onto both the target and the dichoptic mask, the surround suppression effect was found to be dramatically decreased. In addition, the surround suppression was found to depend on the contrast of the dichoptic noise with the greatest surround suppression effect being obtained only when the noise contrast was at an intermediate level. These findings indicate that surround suppression and interocular suppression are not independent of each other, but there are strong interactions between them. Moreover, our results suggest that strong surround suppression may also occur at the fovea and not just the periphery.

  12. Study on the Optimal Equivalent Radius in Calculating the Heat Dissipation of Surrounding Rock

    Directory of Open Access Journals (Sweden)

    H. T. Song

    2015-11-01

    Full Text Available The heat dissipation of surrounding rock of a non-circular roadway is computed using an equivalent circular roadway approach under three circumstances when the area, perimeter, or hydraulic diameter of the circular roadway is equal to the non-circular roadway to obtain the optimal equivalent radius. The differential equations of heat conduction for unstable surrounding rock are established in cylindrical and rectangular coordinate systems using dimensionless analysis method. The calculation formulas of heat dissipation capacity and heat transfer resistance are derived from differential equations. Based on the method of equivalent radius, the similarities and differences between non-circular and circular roadways in calculating the heat dissipation of surrounding rock are discussed. Using the finite volume method, the calculation models for non-circular and circular roadways in the heat dissipation of surrounding rock are also established, among the non-circular roadways including three circumstances, namely, trapezoid, rectangle, and arch. The relation errors of heat dissipation of the surrounding rock of the three equivalent circular roadway methods are investigated for the three non-circular roadways. Results show that the calculation approach with equal perimeters is the best for the heat dissipation of surrounding rock of non-circular roadways.

  13. Influence of Implants Diameter on Bone Stress Distribution of Tooth-implant Supported Fixed Partial Denture%不同直径种植体与天然牙联合支持固定桥的应力分析

    Institute of Scientific and Technical Information of China (English)

    李振; 聂文忠; 黄远亮

    2012-01-01

    Objective: The aim of this study was to analyze stress distribution in the bone of tooth-implant supported fixed partial denture (FPD) with different implant diameters by using a three-dimensional finite element method. Methods: A volunteer was chosen to have a CT scan, and then the DICOM data was processed by the softwares of Mimics, Imageware and ANSYS respectively. The three-dimensional finite element mode of fixed partial denture, which was supported by the second premolar and the second molar or an implant of different diameters (3.5, 4.3, 5.0, 6.0 mm), was constructed in the left mandible. The values of von Mises stress of bone were obtained, when FPD was loaded with vertical or 45 buccolingual force of 200 N. Results: The values of von Mises stress on bone around tooth/implant and abutment were obtained when the fixed partial dentures were loaded with vertical or 45° buccal-lingual oblique force of 200 N respectively. The values of von Mises stress on bone around the second premolar neck varied indistinctively when the fixed partial dentures were loaded with the same force. In different diameter implant-tooth supported fixed partial denture, the von Mises stress of implant neck and abutment decreased obviously when implant diameter increased from 3.5 mm to 4.3 mm, but showed a slow downtrend as the implant diameter continue increasing. Conclusion: With the increase of implant diameter, the values of von Mises stress on bone around implants and abutment decreased, but that of the nature teeth changed little. Under oblique load, the values of von Mises stress on bone around tooth/implant and abutment increased significantly, which might contribute to the failure of FPD.%目的:通过三维有限元方法研究种植体直径对天然牙种植体联合固定桥周围骨组织应力的影响.方法:CT扫描获得志愿者DICOM数据,通过Mimics软件、Imageware逆向工程软件及ANSYS软件处理,先建立左侧下颌第二前磨牙和第二磨牙支持的

  14. Reduced visual surround suppression in schizophrenia shown by measuring contrast detection thresholds

    Science.gov (United States)

    Serrano-Pedraza, Ignacio; Romero-Ferreiro, Verónica; Read, Jenny C. A.; Diéguez-Risco, Teresa; Bagney, Alexandra; Caballero-González, Montserrat; Rodríguez-Torresano, Javier; Rodriguez-Jimenez, Roberto

    2014-01-01

    Visual perception in schizophrenia is attracting a broad interest given the deep knowledge that we have about the visual system in healthy populations. One example is the class of effects known collectively as visual surround suppression. For example, the visibility of a grating located in the visual periphery is impaired by the presence of a surrounding grating of the same spatial frequency and orientation. Previous studies have suggested abnormal visual surround suppression in patients with schizophrenia. Given that schizophrenia patients have cortical alterations including hypofunction of NMDA receptors and reduced concentration of GABA neurotransmitter, which affect lateral inhibitory connections, then they should be relatively better than controls at detecting visual stimuli that are usually suppressed. We tested this hypothesis by measuring contrast detection thresholds using a new stimulus configuration. We tested two groups: 21 schizophrenia patients and 24 healthy subjects. Thresholds were obtained using Bayesian staircases in a four-alternative forced-choice detection task where the target was a grating within a 3∘ Butterworth window that appeared in one of four possible positions at 5∘ eccentricity. We compared three conditions, (a) target with no-surround, (b) target embedded within a surrounding grating of 20∘ diameter and 25% contrast with same spatial frequency and orthogonal orientation, and (c) target embedded within a surrounding grating with parallel (same) orientation. Previous results with healthy populations have shown that contrast thresholds are lower for orthogonal and no-surround (NS) conditions than for parallel surround (PS). The log-ratios between parallel and NS thresholds are used as an index quantifying visual surround suppression. Patients performed poorly compared to controls in the NS and orthogonal-surround conditions. However, they performed as well as controls when the surround was parallel, resulting in significantly

  15. Efficacy and patient satisfaction analysis for fixed implant supported dentures and traditional denture%固定种植义齿与传统义齿修复疗效及患者满意度分析

    Institute of Scientific and Technical Information of China (English)

    贺晓萍

    2014-01-01

    目的:探讨不同义齿修复手段治疗牙列缺损的临床疗效及患者满意度。方法将97例患者分为活动义齿组、固定义齿组及固定种植组3组,治疗后观察患者的主观感受及满意度。结果在咀嚼功能、固定功能、舒适程度、方便程度以及美观程度5个方面,3组患者主观感受有统计学差异(P<0.05);活动义齿组对费用和治疗周期方面满意度最高,固定种植组最低,3组差异有统计学意义(P<0.05)。结论固定种植义齿修复牙列缺损效果好,患者主观感受评价高,但是仍需改进。%Objective To investigate the clinical efficacy and patient satisfaction for different denture means. Methods 97 patients were divided into denture group, fixed partial denture group and fixed implant group, and treated by different denture means, and the subjective feeling and treatment satisfaction was investigated. Results The subjective feeling of masticatory function, fixed function, comfort, convenience and beautiful degree between three groups was statistically significant difference(P<0.05). On cost and treatment cycle, the difference between three groups was significant (P<0.05), the satisfaction in denture group was higher, while in fixed implant group was lower. Conclusion The effect of fixed implant denture restoration for dentition defect is good, the subjective feeling evaluation is high, but still need to be improved.

  16. 泥岩巷道围岩弹塑性参数反演分析与长期稳定性预测%Back analysis of elastoplastic parameters of surrounding rock for roadway in mudstone and its long-term stability prediction

    Institute of Scientific and Technical Information of China (English)

    马非; 贾善坡

    2014-01-01

    以实测的围岩蠕变变形资料为基础,基于现场监测所获得的蠕变本构模型,对某一矿区泥岩体的力学参数进行了弹塑性反演分析,得到的巷道围岩体基本力学参数分别为弹性模量E=2.0 GPa,凝聚力c=1.31 MPa,内摩擦角=24º。待反演参数水平均值的极差结果显示,通过极差的大小可以判断岩土力学参数的敏感性,对蠕变的影响而言,凝聚力最敏感,其次是内摩擦角,弹性模量再次之。在此基础上,利用反演所得的围岩基本力学参数进行了正演,计算得到了各测点处对应的蠕变位移增量,与实测值相比吻合较好,表明反分析所获得的岩体材料参数综合反映了巷道围岩的力学特性。最后,对巷道围岩变形大小及塑性区范围进行了预测。%Based on the observed data of the creep deformation of surrounding rock and creep constitutive model for weak rock mass, back analysis of elastoplastic parameters of surrounding rock for roadway in mudstone is done. The rock mechanical parameters are obtained by back analysis;the obtained elastic modulus is 2.0 GPa;cohesive force is 1.31 MPa and angle of internal friction is 24º. The range analysis results for the mean values of inversion parameters show that the size of the range can be used to judge the sensitivity of rock mechanical parameters. For the creep character, cohesive force is the first influence factor;the second one is the angle of internal friction and the third one is the elastic modulus. Then, deformation of the surrounding rock is calculated using the basic mechanical parameters obtained by back analysis;the creep displacement increment in each observed point is calculated;and they are in good agreement with the measured values. These results show that the actual situation of roadway is reflected by the deduced rock mechanical parameters. Finally, the displacements and plastic zone range of roadway are predicted.

  17. Thermoelectric Performance Enhancement by Surrounding Crystalline Semiconductors with Metallic Nanoparticles

    Science.gov (United States)

    Kim, Hyun-Jung; King, Glen C.; Park, Yeonjoon; Lee, Kunik; Choi, Sang H.

    2011-01-01

    Direct conversion of thermal energy to electricity by thermoelectric (TE) devices may play a key role in future energy production and utilization. However, relatively poor performance of current TE materials has slowed development of new energy conversion applications. Recent reports have shown that the dimensionless Figure of Merit, ZT, for TE devices can be increased beyond the state-of-the-art level by nanoscale structuring of materials to reduce their thermal conductivity. New morphologically designed TE materials have been fabricated at the NASA Langley Research Center, and their characterization is underway. These newly designed materials are based on semiconductor crystal grains whose surfaces are surrounded by metallic nanoparticles. The nanoscale particles are used to tailor the thermal and electrical conduction properties for TE applications by altering the phonon and electron transport pathways. A sample of bismuth telluride decorated with metallic nanoparticles showed less thermal conductivity and twice the electrical conductivity at room temperature as compared to pure Bi2Te3. Apparently, electrons cross easily between semiconductor crystal grains via the intervening metallic nanoparticle bridges, but phonons are scattered at the interfacing gaps. Hence, if the interfacing gap is larger than the mean free path of the phonon, thermal energy transmission from one grain to others is reduced. Here we describe the design and analysis of these new materials that offer substantial improvements in thermoelectric performance.

  18. Expression of zebrafish nos2b surrounds oral cavity.

    Science.gov (United States)

    Poon, Kar-Lai; Richardson, Michael; Korzh, Vladimir

    2008-06-01

    Inducible nitric oxide synthase (NOS2) catalyzes the production of nitric oxide (NO), and is one of the factors establishing innate immunity. In zebrafish, Nos2 is represented by nos2a and nos2b. Here, we report the cloning and expression pattern of the zebrafish nos2b gene, which does not seem to participate in induced immune response. nos2b was mapped to zebrafish linkage group 15. The spatial and temporal expression pattern of nos2b in embryonic zebrafish was analyzed by whole-mount in situ hybridization. nos2b is expressed constitutively in two primordia located along the ventral midline. The first group of cells contributes to the neurohypophysis. Initially at the level of the ventral hindbrain, the second group of cells migrates closely with the thyroid primordium to its final position at the basihyal by 3 dpf. Thus, the analysis of expression pattern of nos2b reveals complex morphogenetic movements resulting in its expression surrounding the oral cavity.

  19. Investigation of Thermal Equilibrium around an Accidental Event and Impact on Possibly Enclosed Surrounding Environment

    Science.gov (United States)

    Sarkar, Biswanath; Shah, Nitin; Choukekar, Ketan; Kapoor, Himanshu; Kumar, Uday; Das, Jotirmoy; Bhattacharaya, Ritendra; Vaghela, Hitensinh; Muralidhara, Srinivasa

    Complex and large cryogenic distribution systems are integral part of a fusion machine having superconducting magnets, cryopumps, etc. The various equipment of the cryogenic distribution system are interconnected via Cryogenic Transfer Lines (CTLs) to distribute cold helium to end users. During nominal operation of the fusion machine, helium inventory in CTLs could be in order of several tons. The cold helium present in CTLs could be released in surrounding volume due to accidental scenario. The present analysis, aims to estimate lowest temperature in the surrounding volume due to accidental scenario. The paper will describe simulation results and the test plan in a simulated condition.

  20. Surrounding Moving Obstacle Detection for Autonomous Driving Using Stereo Vision

    Directory of Open Access Journals (Sweden)

    Hao Sun

    2013-06-01

    Full Text Available Detection and tracking surrounding moving obstacles such as vehicles and pedestrians are crucial for the safety of mobile robotics and autonomous vehicles. This is especially the case in urban driving scenarios. This paper presents a novel framework for surrounding moving obstacles detection using binocular stereo vision. The contributions of our work are threefold. Firstly, a multiview feature matching scheme is presented for simultaneous stereo correspondence and motion correspondence searching. Secondly, the multiview geometry constraint derived from the relative camera positions in pairs of consecutive stereo views is exploited for surrounding moving obstacles detection. Thirdly, an adaptive particle filter is proposed for tracking of multiple moving obstacles in surrounding areas. Experimental results from real‐world driving sequences demonstrate the effectiveness and robustness of the proposed framework.

  1. Surrounding Moving Obstacle Detection for Autonomous Driving Using Stereo Vision

    OpenAIRE

    Hao Sun; Huanxin Zou; Shilin Zhou; Cheng Wang; Naser El-Sheimy

    2013-01-01

    Detection and tracking surrounding moving obstacles such as vehicles and pedestrians are crucial for the safety of mobile robotics and autonomous vehicles. This is especially the case in urban driving scenarios. This paper presents a novel framework for surrounding moving obstacles detection using binocular stereo vision. The contributions of our work are threefold. Firstly, a multiview feature matching scheme is presented for simultaneous stereo correspondence and motion correspondence searc...

  2. Modelling leisure day trips between Berlin and its surrounding

    OpenAIRE

    Beuck, Ulrike

    2005-01-01

    The paper describes the development, application and validation of a quantitative spatial model for leisure day trips from Berlin into the surrounding regions. Leisure activities can contribute substantially to the economies of rural regions like the surroundings of Berlin, but these activities are also often very sensitive to environmental quality, which is usually negatively affected by the traffic caused by the leisure travelers...A model of the spatial distribution of leisure day trips ca...

  3. Inhibitory Stabilization of the Cortical Network Underlies Visual Surround Suppression

    OpenAIRE

    Ozeki, Hirofumi; Finn, Ian M.; Schaffer, Evan S.; Miller, Kenneth D.; Ferster, David

    2009-01-01

    In what regime does the cortical circuit operate? Our intracellular studies of surround suppression in cat primary visual cortex (V1) provide strong evidence on this question. Although suppression has been thought to arise from an increase in lateral inhibition, we find that the inhibition that cells receive is reduced, not increased, by a surround stimulus. Instead, suppression is mediated by a withdrawal of excitation. Thalamic recordings and previous work show that these effects cannot be ...

  4. Macro mechanical parameters' size effect of surrounding rock of Shuibuya project's underground power station

    Institute of Scientific and Technical Information of China (English)

    GUO Zhi-hua; ZHOU Chuang-bing; ZHOU Huo-ming; SHENG Qian; LENG Xian-lun

    2005-01-01

    Scale effect is one of the important aspects in the macro mechanical parameters' research of rock mass, from a new point of view, by means of lab and field rock mechanics test, establishment of E~Vp relation, classification of engineering rock mass, numerical simulation test and back analysis based on surrounding rock's displacement monitoring results of Shuibuya Project's underground power station, rock mass deformation module's size effect of surrounding rock of Shuibuya Project's undegroud power station was studied. It's shown that rock mass deformation module's scale effect of surrounding rock of Shuibuya Project's undeground power station is obvious, the rock mass deformation module to tranquilization is 20% of intact rock's. Finally the relation between rock mass deformation modules and the scale of research was established.

  5. Damage Characteristics of Surrounding Rock Subjected to VCR Mining Blasting Shock

    Directory of Open Access Journals (Sweden)

    Nan Jiang

    2015-01-01

    Full Text Available For limiting the damage range caused by explosive shock loads in vertical crater retreat (VCR mining, the blasting damage characteristics of surrounding rock were studied by two methods: numerical simulation and ultrasonic testing. Combined with the mining blasting in Dongguashan Copper Mine of China, the VCR blasting shock characteristics under different conditions are obtained by using LSDYNA. Based on statistical fracture mechanics and damage mechanics theories, a damage constitutive model for rock mass subjected to blasting shock load was established. Then by using the fast Lagrange analysis codes (FLAC3D, the blasting damage characteristics of surrounding rock were analyzed by applying the blasting shock loads obtained from the VCR mining and the damage zone is obtained. At last, the relationship between the amount of explosives and the radius of damaged surrounding rock mass was discussed, and its formula was also derived. The research provides a theoretical basis for rationally controlling stope boundaries and optimizing mining blasting parameters.

  6. "Tilt" in color space: Hue changes induced by chromatic surrounds.

    Science.gov (United States)

    Klauke, Susanne; Wachtler, Thomas

    2015-01-01

    The perceived color of a chromatic stimulus is influenced by the chromaticity of its surround. To investigate these influences along the dimension of hue, we measured hue changes induced in stimuli of different hues by isoluminant chromatic surrounds. Generally, induced hue changes were directed in color space away from the hue of the inducing surround and depended on the magnitude on the hue difference between stimulus and surround. With increasing difference in hue between stimulus and surround, induced hue changes increased up to a maximum and then decreased for larger differences. This qualitative pattern was similar for different inducers, but quantitatively, induction was weaker along some directions in cone-opponent color space than along other directions. The strongest induction effects were found along an oblique, blue-yellow axis that corresponds to the daylight axis. The overall pattern of the induction effect shows similarities to the well-known tilt effect, where shifts in perceived angle of oriented stimuli are induced by oriented surrounds. This suggests analogous neural representations and similar mechanisms of contextual processing for different visual features such as orientation and color.

  7. The activities and perspectives of improvement the polluted waste in surrounding rivers in Bucim mine area

    OpenAIRE

    Danevski, Tome; Golomeova, Mirjana; Krstev, Boris; Golomeov, Blagoj; Zendelska, Afrodita; Krstev, Aleksandar; Gocev, Zivko

    2013-01-01

    The presentation of the influence that the tailing dump or waste as well as the flotation hydro-tailing dump over the environment around the region of copper mine Bucim, surrounding rivers, places, villages, appearance of dust, pollution of ambient air and mine tailing pond. Generally speaking, the monitoring will be done for two periods. The first analysis relating to the period from the year 2005, and the second analysis relating to the period from the year 2010/2012. The monitoring ...

  8. Forest Fragments Surrounded by Sugar Cane Are More Inhospitable to Terrestrial Amphibian Abundance Than Fragments Surrounded by Pasture

    Directory of Open Access Journals (Sweden)

    Paula Eveline Ribeiro D’Anunciação

    2013-01-01

    Full Text Available In recent years, there has been increasing interest in matrix-type influence on forest fragments. Terrestrial amphibians are good bioindicators for this kind of research because of low vagility and high philopatry. This study compared richness, abundance, and species composition of terrestrial amphibians through pitfall traps in two sets of semideciduous seasonal forest fragments in southeastern Brazil, according to the predominant surrounding matrix (sugar cane and pasture. There were no differences in richness, but fragments surrounded by sugar cane had the lowest abundance of amphibians, whereas fragments surrounded by pastures had greater abundance. The most abundant species, Rhinella ornata, showed no biometric differences between fragment groups but like many other amphibians sampled showed very low numbers of individuals in fragments dominated by sugar cane fields. Our data indicate that the sugar cane matrix negatively influences the community of amphibians present in fragments surrounded by this type of land use.

  9. Comparison of the Effect between the Locator Attachment and Ball Cap Attachment Used in Clinically Implant-supported Overdentures%临床种植覆盖义齿中Locator附着体与球帽式附着体的效果比较

    Institute of Scientific and Technical Information of China (English)

    徐莉亚; 李春林; 胡劲松

    2015-01-01

    Objective:To compare the effect between the Locator attachment and the ball attachment in clinically implant-supported overdentures.Method:98 edentulous patients for the cover denture in our hospital from June 2013 to June 2014 were selected,they were divided into the Locator group for 12 cases and the ball cap type group for 18 cases according to the random number table method.The Locator group was given Locator attachment,the ball cap type group was given ball attachment.After the denture completion,the conditions of implant soft tissue between the two groups were observed and the satisfaction survey to the patients was made.Result:The indexes related to oral soft tissue such as the gingival index, plaque index and calculus index of the two groups,there were no significant differences(P>0.05).The retention,comfort and mastication satisfaction of implant-supported overdentures in the Locator group were significantly higher than those in the ball cap type group,the differences were statistically significant(P0.05)。Locator组患者种植覆盖义齿的固位、舒适、咀嚼满意度均明显高于球帽式组,差异均有统计学意义(P<0.05)。结论:Locator附着体与球帽式附着体覆盖义齿均有较好的治疗效果,患者对Locator附着体满意度有较高的评价,可以优先考虑Locator附着体覆盖义齿修复。

  10. DEFORMATION OF MOISTURE FLUX CIRCULATION SURROUNDING THE LANDFALL TYPHOON "BILIS"

    Institute of Scientific and Technical Information of China (English)

    RAN Ling-kun; YANG Wen-xia; HONG Yan-chao

    2009-01-01

    The deformation parameter (DP), which is defined as the product of shear deformation and stretching deformation of moisture flux circulation, is introduced. The tendency equation of DP is derived in pressure coordinates. Furthermore, DP is used to diagnose the deformation character of moisture flux circulation in the periphery of Bilis. The analysis showed that before Bilis landed, DP presented eight abnormal areas, which distributed alternately and closely encircled the low-pressure center. This indicated that the moisture flux circulation in the periphery of Bilis rotated counterclockwise and stretched longitudinally and latitudinally to deform. After Bilis landed, DP weakened gradually and its regular pattern of horizontal distribution loosened. The shear and stretching deformations of moisture flux circulation surrounding Bilis weakened after the typhoon landed. The deformation of moisture flux circulation in the periphery of Bilis mainly appeared in the middle-lower troposphere. There existed 1/2 phase difference between the shear and stretching deformations in the vertical-latitudinal cross section and a π/4 phase difference between them on the horizontal plane. As Bilis landed and further moved inland of China, the intensities of DP, shear and stretching deformations decreased, meanwhile their vertical and horizontal structures became irregular. The chief dynamic factors responsible for the deformation of moisture flux circulation in the periphery of Bilis were the three terms associated with the three-dimensional advection transportation of DP, square difference between shear and stretching deformations coupling with Coriolis parameter, and horizontal gradient of geopotential height before Bilis landed. The last two dynamic factors impacted jointly on the deformation of moisture flux circulation after Bilis landed.

  11. Platelets surrounding primary tumor cells are related to chemoresistance.

    Science.gov (United States)

    Ishikawa, Satoko; Miyashita, Tomoharu; Inokuchi, Masafumi; Hayashi, Hironori; Oyama, Katsunobu; Tajima, Hidehiro; Takamura, Hironori; Ninomiya, Itasu; Ahmed, A Karim; Harman, John W; Fushida, Sachio; Ohta, Tetsuo

    2016-08-01

    Platelets are crucial components of the tumor microenvironment that function to promote tumor progression and metastasis. In the circulation, the interaction between tumor cells and platelets increases invasiveness, protects tumor cells from shear stress and immune surveillance, and facilitates tumor cell extravasation to distant sites. However, the role and presence of platelets in the primary tumor have not been fully determined. Here, we investigated the presence of platelets around breast cancer primary tumor cells and the associations between these cells. We further investigated the associations among platelets, tumor cells, chemoresistance, and epithelial-mesenchymal transition (EMT). We retrospectively analyzed data from 74 patients with human epidermal growth factor receptor 2 (HER2)‑negative breast cancer who underwent biopsies before treatment and subsequent neo-adjuvant chemotherapy. In biopsy specimens, we evaluated the expression of platelet-specific markers and EMT markers using immunohistochemistry. The associations among the expression of platelet‑specific markers in biopsy specimens, EMT, response to neo‑adjuvant chemotherapy, and survival were analyzed. The presence of platelets was observed in 44 out of 74 (59%) primary breast cancer biopsy specimens. Platelet‑positive tumor cells showed EMT‑like morphological changes and EMT marker expression. Primary tumor cells associated with platelets were less responsive to neo‑adjuvant chemotherapy (pCR rate: 10 vs. 50%, respectively; p=0.0001). Platelets were an independent predictor of the response to chemotherapy upon multivariable analysis (pbreast cancer. Platelets surrounding primary tumor cells may represent novel predictors of chemotherapeutic responses. PMID:27349611

  12. Mechanism of zonal disintegration in surrounding rock mass around deep rock engineering and its application

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The mechanical behaviors of deep rock mass are different from those of shallow rock mass.Through cases of Jinping II Hydropower Station,the special phenomenon of zonal disintegration in the surrounding rock mass around the diversion tunnels,is analyzed.On the basis of fracture mechanics,a new strength criterion for deep rock mass is derived.The new nonlinear strength criterion that is relative to the rock mass rating classification can be applied to the study of the tensile failure of deep rock mass.Subsequently,zonal disintegration model is established,and the radius of fractured zone and none-fractured zone of deep surrounding rock mass around cylindrical tunnel are obtained,their exact positions and the evolution law of zonal disintegration of surrounding rock mass is determined.To validate the present model,comparison between calculation results and the experiment observation on facture and failure around underground openings is carried out.It is found that the numerical simulation result is in good agreement with the experimental one on failure modes around the hole.Through sensitivity analysis,the effects of stress condition,cohesion and the angle of internal friction on the phenomenon of zonal disintegration are determined.Finally,the present model is adopted in the analysis of the zonal disintegration in the surrounding rock mass around the diversion tunnels in Jinping II Hydropower Station.Meanwhile,the magnitude and distributions of fractured zones are determined by numerical simulation.

  13. Orientation-tuned surround suppression in mouse visual cortex

    NARCIS (Netherlands)

    Self, Matthew W; Lorteije, Jeannette A M; Vangeneugden, Joris; van Beest, Enny H; Grigore, Mihaela E; Levelt, Christiaan N; Heimel, J.A.; Roelfsema, Pieter R

    2014-01-01

    The firing rates of neurons in primary visual cortex (V1) are suppressed by large stimuli, an effect known as surround suppression. In cats and monkeys, the strength of suppression is sensitive to orientation; responses to regions containing uniform orientations are more suppressed than those contai

  14. Metrizamide demonstration of the subarachnoid space surrounding the Gasserian ganglion

    Energy Technology Data Exchange (ETDEWEB)

    Christmann, D.; Babin, E.

    1980-05-01

    The chance opacification of the subarachnoid space surrounding the Gasserian ganglion, observed during metrizamide basal cisternography, is reported. This is compared to similar demonstrations of the optic subarachnoid space. Such infrequently observed images should be known because they may be related to the occurrence of trigeminal neuralgia.

  15. A Large-scale Shock Surrounding a Powerful Radio Galaxy?

    NARCIS (Netherlands)

    Croston, J. H.; Hardcastle, M. J.; Mingo, B.; Evans, D. A.; Dicken, D.; Morganti, R.; Tadhunter, C. N.

    2011-01-01

    We report Chandra evidence for a 200 kpc scale shock in the cluster surrounding the powerful radio galaxy 3C 444. Our 20 ks observation allows us to identify a clear surface brightness drop around the outer edge of the radio galaxy, which is likely to correspond to a spheroidal shock propagating int

  16. Challenges Surrounding the Education of Children with Chronic Diseases

    Science.gov (United States)

    Gordon, Maria, Ed.

    2016-01-01

    While governing bodies have mandated that all students have the right to an education, with disabled students treated to the same rights and opportunities as non-disabled students, policymakers do not always agree on what all-inclusive education should look like. "Challenges Surrounding the Education of Children with Chronic Diseases"…

  17. Development of fractures in soft rock surrounding a roadway and their control

    Institute of Scientific and Technical Information of China (English)

    Li Xuehua; Yao Qiangling; Man Jiankang; Chen Chaoqun; He Lihui

    2011-01-01

    As the excavation of roadway,new fractures will be formed and the pre-existing fractures extend with the redistribution of stress in surrounding rocks.Eventually,fracture zone and bed separation are formed in rocks because of the developed fractures.Therefore,mastering the fracture evolution of surrounding rocks is very important to maintain the stability of roadway.The surrounding rocks of main haulage roadway in a certain coal mine is so broken and loose that the supporting is very difficult.Based on comprehensive analysis of the engineering geological conditions,a sight instrument was used to observe the fractures of internal surrounding rocks.Four indices,i.e.,the width of fracture zone W,the number of fractures n,the width of fractures d and rock fracture designation RFD,are put forward to evaluate the fracture development.According to the evolution rules of the soft rock roadway from this paper,control principles by stages and by regions are presented through the research.At the same time,the best time of grouting reinforcement is determined on the basis of fracture saturation.Field practice shows that the roadway can satisfy normal production during service periods by suitable first support and grouting reinforcement.

  18. Investigation and assessment of tritium concentration of aquatic environment surrounding haiyang nuclear power plant

    International Nuclear Information System (INIS)

    Objective: To investigate tritium concentrations of aquatic environment surrounding Haiyang nuclear power plant, and make a analysis of the influencial factors of the tritium concentration; to assess the accumulated-effective dose of the residents surrounding nuclear power plant. Methods: We collected 16 sample points, including surface water, groundwater, drinking water and sea water within 30 km surrounding Haiyang nuclear power plant in wet period and dry period. The pretreatment and preparation of samples referred to the recommended methods of the national standards GB 12375-90. The low background liquid scintillation spectrometer is used to measure the tritium concentration. Result: The average level of the tritium concentration of water samples was (0.62 ± 0.163) Bq · L-1, the range of the tritium concentrations was from 0.27Bq · L-1 to 0.93Bq · L-1. The difference of the tritium concentrations between two different periods analyzed by the paired t test was considered statistically significant. (P-1, 0.008 μ Sv · a-1, 0.007 μ Sv · a-1, respectively. Conclusion: The activity concentration of tritium in the aquatic environment surrounding Haiyang nuclear power plant was at the lower level than that of others; according to the limited value that is regulated by basic standards for protection against ionizing radiation and of the safety of radiation sources (GB 18871-2002) (2 mSv), the accumulated-effective dose which residents suffered was in background level of radiation. (authors)

  19. Nanoscale heat transfer and phase transformation surrounding intensely heated nanoparticles

    Science.gov (United States)

    Sasikumar, Kiran

    Over the last decade there has been significant ongoing research to use nanoparticles for hyperthermia-based destruction of cancer cells. In this regard, the investigation of highly non-equilibrium thermal systems created by ultrafast laser excitation is a particularly challenging and important aspect of nanoscale heat transfer. It has been observed experimentally that noble metal nanoparticles, illuminated by radiation at the plasmon resonance wavelength, can act as localized heat sources at nanometer-length scales. Achieving biological response by delivering heat via nanoscale heat sources has also been demonstrated. However, an understanding of the thermal transport at these scales and associated phase transformations is lacking. A striking observation made in several laser-heating experiments is that embedded metal nanoparticles heated to extreme temperatures may even melt without an associated boiling of the surrounding fluid. This unusual phase stability is not well understood and designing experiments to understand the physics of this phenomenon is a challenging task. In this thesis, we will resort to molecular dynamics (MD) simulations, which offer a powerful tool to investigate this phenomenon, without assumptions underlying continuum-level model formulations. We present the results from a series of steady state and transient non-equilibrium MD simulations performed on an intensely heated nanoparticle immersed in a model liquid. For small nanoparticles (1-10 nm in diameter) we observe a stable liquid phase near the nanoparticle surface, which can be at a temperature well above the boiling point. Furthermore, we report the existence of a critical nanoparticle size (4 nm in diameter) below which we do not observe formation of vapor even when local fluid temperatures exceed the critical temperature. Instead, we report the existence of a stable fluid region with a density much larger than that of the vapor phase. We explain this stability in terms of the

  20. Research on characters of surrounding rock in complex geology conditions and supporting time

    Institute of Scientific and Technical Information of China (English)

    Yu Weijian; Gao Qian; Zhai Shuhua; Zhang Meihua

    2008-01-01

    The methods combined by test, field monitoring and theoretical analysis were adopted to do the systemic re- search on the rock mass from micro-structure to macro-deformation, and rheological model of Jinchuan rock mass was es-tablished to discuss the reasonable supporting time. Results show that supporting after suitable stress and displacement release can benefit for the long-term stability of surrounding rock.

  1. Physics and technology of vertical surrounding gate MOSFETs

    Science.gov (United States)

    Auth, Christopher Patrick

    As semiconductor devices are scaled into the sub-0.1mum regime, lithographic issues become paramount in further scaling. Additionally, short-channel and poor subthreshold characteristics continue to plague planar MOSFETs. Double-gate or surrounding-gate MOSFETs fabricated on SOI substrates have shown promise in reducing the short channel problems and achieving a nearly ideal subthreshold slope. These devices are hampered by process complexity and floating body effects. They also remain dependent on lithographic techniques for scaling. The vertical, surrounding-gate MOSFET is starting to attract increasing attention for its ability to overcome these problems. Scaling of the channel length is no longer tied to lithography. They have a much smaller footprint than planar devices and the surrounding gate improves control of the gate over the channel potential reducing short channel effects. The vertical structure also decouples the channel length from the packing density. This work will present both simulation and experimental results which were used to examine the potential for the vertical MOSFET in deep submicron applications. The simulation results show an advantage of the cylindrical, surrounding-gate MOSFET over the double-gate structure for short channel length transistors. This improvement results from the increased proximity of the gate to the channel in the cylindrical structure. The benefit of this improved control is illustrated through derivation of a scaling theory for cylindrical MOSFETs. This scaling theory is used as a basis for comparing the cylindrical, surrounding-gate MOSFET to the double-gate MOSFET. Experimental results for vertical, surrounding-gate MOSFETs fabricated on pillars of silicon down to 300A thick are presented, illustrating the potential for fabricating the device at sub-0.1mum dimensions. The results illustrate the features of the device as it is scaled to small pillar thicknesses. The experimental results are compared to both

  2. Experimental Study of Deformation of Surrounding Rock with Infrared Radiation

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yong-jun; AN Li-qian; REN Run-hou; FAN Shi-min; MA Nian-jie; LI Jian-hui; JI Yuan-ming

    2005-01-01

    According to the practical conditions of coal roadway in Changcun Coal Mine of Lu'an Mining Group, the deformation of rock surrounding roadway was experimentally studied by means of thermal infrared (TIR) imaging system in the process of confined compressions. It is found that the model surface TIR temperature (TIRT) changes with the increase of load. Furthermore, TIRT changes non-synchronously in different ranges such as the roof, floor, wall, corners and bolted ranges. The TIRT is higher in the location of stress concentration and bolted ranges than that in the location of stress relaxation and broken ranges. The interaction ranges of bolt and rock are determined preliminarily according to the corresponding relationship of TIRT fields and the strain fields of the surrounding rock. The new method of TIR image processing has been proved to be effective for the study of bolt support and observation of roadway stability under mine pressure.

  3. Dynamics of two-component membranes surrounded by viscoelastic media

    International Nuclear Information System (INIS)

    We discuss the dynamics of two-component fluid membranes which are surrounded by viscoelastic media. We assume that membrane-embedded proteins can diffuse laterally and induce a local membrane curvature. The mean squared displacement of a tagged membrane segment is obtained as a generalized Einstein relation. When the elasticity of the surrounding media obeys a power-law behavior in frequency, an anomalous diffusion of the membrane segment is predicted. We also consider the situation where the proteins generate active non-equilibrium forces. The generalized Einstein relation is further modified by an effective temperature that depends on the force dipole energy. The obtained generalized Einstein relations are useful for membrane microrheology experiments. (fast track communication)

  4. Study on Temperature Fieldof Surrounding Rock with BEM

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The authors analyzed the characteristic of surrounding rock temperature field around a drifting face, setup its mathematic model, and got its numerical result with the boundary element method(BEM). To calculate in-tra-domain integral, it was transformed into boundary integration with the DRM method. Using the similitude the-ory, the dimensionless differential equation was educed. Finally, the authors calculated two drifting faces of San-hejian Coal Mine using the computer software developed by authors based on the above principium, and got the dis-tribution characteristic of surrounding rock temperature field around a drifting face and the periodic variation intemperature with its periodic moving forward. Comparing the calculated heat dissipating-capacity of surroundingrock with the measured data shows that the computer software is proper.

  5. Dynamics of two-component membranes surrounded by viscoelastic media.

    Science.gov (United States)

    Komura, Shigeyuki; Yasuda, Kento; Okamoto, Ryuichi

    2015-11-01

    We discuss the dynamics of two-component fluid membranes which are surrounded by viscoelastic media. We assume that membrane-embedded proteins can diffuse laterally and induce a local membrane curvature. The mean squared displacement of a tagged membrane segment is obtained as a generalized Einstein relation. When the elasticity of the surrounding media obeys a power-law behavior in frequency, an anomalous diffusion of the membrane segment is predicted. We also consider the situation where the proteins generate active non-equilibrium forces. The generalized Einstein relation is further modified by an effective temperature that depends on the force dipole energy. The obtained generalized Einstein relations are useful for membrane microrheology experiments.

  6. Damage Surrounding Dynamically Propagating Shear Cracks in Granodiorite (Invited)

    Science.gov (United States)

    Faulkner, D. R.; Faulkner, R. G.; Cembrano, J. M.; Jensen, E.

    2009-12-01

    Quantifying the microfracture damage surrounding faults and fractures is important for predicting the fluid flow properties of rock masses. Damage surrounding faults has been attributed to fault growth, geometric irregularities, and earthquake rupture. Up to now, earthquake rupture can only be inferred when pseudotachylyte is present, indicating shear heating leading to melt production. We describe shear fractures that have developed a relatively isotropic granodioritic protolith within the Atacama fault system in northern Chile. These fractures have an alteration zone produced as a result of intense microfracture damage surrounding the fractures. These alteration zones taper out towards the fracture tips. The alteration zone also shows asymmetry either side of the fracture that can be used to infer the propagation direction of the fracture. We interpret these observations as being due to a waning fracture tip stress field of a dynamically propagating shear crack. In contrast, simple fracture mechanics models indicate a quasi-statically propagating fracture would be expected to produce an expanding zone of damage at the crack tip as displacement accumulates. Another explanation for the reduction in alteration zone width might be extension of the fracture tips by sub-critical crack growth. The width of alteration zone has a positive correlation with the shear displacement and a zero intercept. The slope of this correlation is steeper than for microfracture damage zone widths measured on larger displacement faults in the same region. We suggest that this indicates a different mode of formation; that of damage surrounding a dynamically propagating shear fracture. At higher displacements, additional processes such as those mentioned earlier contribute to the width of the microfracture damage zone, and the rate of growth with displacement is not so pronounced.

  7. Belief and Attitudes surrounding Childhood Autism in Ghana

    OpenAIRE

    Manu, Naomi

    2012-01-01

    Autism is a life-long invisible impairment with an unknown etiology. Current literature shows an increase in the diagnosis of autism worldwide. This qualitative study explores the attitudes and beliefs which surround childhood autism in Ghana. In-depth interviews were conducted with four (4) parents whose children have autism and three (3) key informants; a Religious Leader, a Health Worker and an Administrator of a Special school in Accra, Ghana. A semi-structured interview guide was used fo...

  8. Modelling of Jet Grouting and its interactions with surrounding soils

    OpenAIRE

    Gesto Beiroa, José Manuel; Gens Solé, Antonio; Arroyo Alvarez de Toledo, Marcos

    2012-01-01

    The versatility of Jet-Grouting as a soil improvement technique has made this procedure to be widely used in geotechnical engineering practice. In this work we discuss some aspects related to the THMC coupling phenomena that may arise when the Jet-Grouting technique is employed. Namely, we describe some basic constitutive models that may be appropriate to simulate the response of the surrounding soils and that of the Jet-Grouted soil itself while those interactions take place.

  9. Noise in the surrounding farms for fattening bulls.

    OpenAIRE

    KRAJÍČEK, Karel

    2011-01-01

    This Bachelor Thesis studies the Noise Pollution Issue in the surrounding of a Bull Farm. In Theoretical Part there are explained the basic noise concepts, its circumscription, sources, effects on Human health and basic prevention and antinoise protective agents. There is a brief introduction of the examined Farm and Livestock as well. In Practical Part there are indicated measurement procedures, their subsequent evaluation and assessment according to relevant standards and regulations.

  10. The experiences of gardens and gardening at the housing surroundings

    OpenAIRE

    Paris, Magali

    2008-01-01

    International audience How does gardening the housing surroundings –as done by the residents- contribute to rediscover a sense of time that could help to manage spatial proximity? Our research, conducted within the architectural and urban ambiances research center (Grenoble, France), focuses on this question. More precisely, we theorize that: Gardening a doorstep garden is an everyday life experiment in the modeling of sensorial materials with human relationships. This experiment leads to ...

  11. Orientation-tuned surround suppression in mouse visual cortex

    OpenAIRE

    Self, Matthew W.; Lorteije, Jeannette A. M.; Vangeneugden, Joris; van Beest, Enny H; Grigore, Mihaela E; Levelt, Christiaan N.; Heimel, J.A.; Roelfsema, Pieter R.

    2014-01-01

    The firing rates of neurons in primary visual cortex (V1) are suppressed by large stimuli, an effect known as surround suppression. In cats and monkeys, the strength of suppression is sensitive to orientation; responses to regions containing uniform orientations are more suppressed than those containing orientation contrast. This effect is thought to be important for scene segmentation, but the underlying neural mechanisms are poorly understood. We asked whether it is possible to study these ...

  12. High resolution bathymetry of China seas and their surroundings

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Based on the oceanic lithospheric flexure and the worldwide bathymetric data ETOPO5, the high resolu tion bathymetry of the China seas and their surroundings is computed from altimeter derived gravity anomalies. The new bathymetry obtained by this study is higher resolution and accuracy than the widely used ETOPO5 data, mean while it shows clearly the seafioor, the tectonic characteristics and the geodynamical processes in the China seas.

  13. A permeability barrier surrounds taste buds in lingual epithelia.

    Science.gov (United States)

    Dando, Robin; Pereira, Elizabeth; Kurian, Mani; Barro-Soria, Rene; Chaudhari, Nirupa; Roper, Stephen D

    2015-01-01

    Epithelial tissues are characterized by specialized cell-cell junctions, typically localized to the apical regions of cells. These junctions are formed by interacting membrane proteins and by cytoskeletal and extracellular matrix components. Within the lingual epithelium, tight junctions join the apical tips of the gustatory sensory cells in taste buds. These junctions constitute a selective barrier that limits penetration of chemosensory stimuli into taste buds (Michlig et al. J Comp Neurol 502: 1003-1011, 2007). We tested the ability of chemical compounds to permeate into sensory end organs in the lingual epithelium. Our findings reveal a robust barrier that surrounds the entire body of taste buds, not limited to the apical tight junctions. This barrier prevents penetration of many, but not all, compounds, whether they are applied topically, injected into the parenchyma of the tongue, or circulating in the blood supply, into taste buds. Enzymatic treatments indicate that this barrier likely includes glycosaminoglycans, as it was disrupted by chondroitinase but, less effectively, by proteases. The barrier surrounding taste buds could also be disrupted by brief treatment of lingual tissue samples with DMSO. Brief exposure of lingual slices to DMSO did not affect the ability of taste buds within the slice to respond to chemical stimulation. The existence of a highly impermeable barrier surrounding taste buds and methods to break through this barrier may be relevant to basic research and to clinical treatments of taste.

  14. Surrounding material effect on measurement of thunderstorm-related neutrons

    CERN Document Server

    Tsuchiya, H

    2014-01-01

    Observations of strong flux of low-energy neutrons were made by $^{3}\\mathrm{He}$ counters during thunderstorms [Gurevich et al (Phys. Rev. Lett. 108, 125001, 2012)]. How the unprecedented enhancements were produced remains elusive. To better elucidate the mechanism, a simulation study of surrounding material impacts on measurement by $^{3}\\mathrm{He}$ counters was performed with GEANT4. It was found that unlike previously thought, a $^3\\mathrm{He}$ counter had a small sensitivity to high-energy gamma rays because of inelastic interaction with its cathode-tube materials (Al or stainless steel). A $^{3}\\mathrm{He}$ counter with the intrinsic small sensitivity, if surrounded by thick materials, would largely detect thunderstorm-related gamma rays rather than those neutrons produced via photonuclear reaction in the atmosphere. On the other hand, the counter, if surrounded by thin materials and located away from a gamma-ray source, would observe neutron signals with little gamma-ray contamination. Compared with t...

  15. Contrast enhancement algorithm considering surrounding information by illumination image

    Science.gov (United States)

    Song, Ki Sun; Kang, Hee; Kang, Moon Gi

    2014-09-01

    We propose a contrast enhancement algorithm considering surrounding information by illumination image. Conventional contrast enhancement techniques can be classified as a retinex-based method and a tone mapping function-based method. However, many retinex methods suffer from high-computational costs or halo artifacts. To cope with these problems, efficient edge-preserving smoothing methods have been researched. Tone mapping function-based methods are limited in terms of enhancement since they are applied without considering surrounding information. To solve these problems, we estimate an illumination image with local adaptive smoothness, and then utilize it as surrounding information. The local adaptive smoothness is calculated by using illumination image properties and an edge-adaptive filter based on the just noticeable difference model. Additionally, we employ a resizing method instead of a blur kernel to reduce the computational cost of illumination estimation. The estimated illumination image is incorporated with the tone mapping function to address the limitations of the tone mapping function-based method. With this approach, the amount of local contrast enhancement is increased. Experimental results show that the proposed algorithm enhances both global and local contrasts and produces better performance in objective evaluation metrics while preventing a halo artifact.

  16. THE DESIGN OF DYNAMIC SIMULATION SYSTEM ON EARTHQUAKE SURROUNDINGS

    Institute of Scientific and Technical Information of China (English)

    沈毅力; 杨云; 李天石

    2003-01-01

    Objective To design a system that can simulate earthquake surroundings. In the surroundings, people can be familiar with the omen, strong shock and aftershock of earthquake, thus make right choices and get away when the disaster occurs. Methods The system consists of an electro-hydraulic servo system, a whole-information sound system and some lighting device; By using the adaptive inverse control method and LMS algorithms, the inverse model (I.e. The controller) is convergent rapidly; The software based on LabVIEW makes the parameters can be modified easily; There is a double closed-loop structure in the system: an analog closed-loop and a digital closed-loop, and their parameters can be inspected in real time. Results The system is of very high reliability, and the desired vibration signal can be tracked exactly by output. Conclusion Earthquake surroundings is simulated vividly. Through the system, people can be familiar with earthquake phenomena, and know lots of knowledge of earthquake.

  17. Camouflaging in a complex environment--octopuses use specific features of their surroundings for background matching.

    Directory of Open Access Journals (Sweden)

    Noam Josef

    Full Text Available Living under intense predation pressure, octopuses evolved an effective and impressive camouflaging ability that exploits features of their surroundings to enable them to "blend in." To achieve such background matching, an animal may use general resemblance and reproduce characteristics of its entire surroundings, or it may imitate a specific object in its immediate environment. Using image analysis algorithms, we examined correlations between octopuses and their backgrounds. Field experiments show that when camouflaging, Octopus cyanea and O. vulgaris base their body patterns on selected features of nearby objects rather than attempting to match a large field of view. Such an approach enables the octopus to camouflage in partly occluded environments and to solve the problem of differences in appearance as a function of the viewing inclination of the observer.

  18. Can texture of tissue surrounding microcalcifications in mammography be used for breast cancer diagnosis?

    Science.gov (United States)

    Karahaliou, A.; Boniatis, I.; Sakellaropoulos, P.; Skiadopoulos, S.; Panayiotakis, G.; Costaridou, L.

    2007-10-01

    This study investigates whether texture properties of the tissue surrounding microcalcifications (MCs) can contribute to breast cancer diagnosis. A case sample of 100 MC clusters (46 benign, 54 malignant) from 85 dense mammographic images included in the Digital Database for Screening Mammography, is analyzed. Regions of interest containing clusters are processed using wavelet-based enhancement and individual MCs are segmented by local thresholding. The segmented MCs are removed from original image data and the surrounding tissue area is subjected to texture analysis. The feasibility of four texture feature sets (first-order statistics, gray level co-occurrence matrices, gray level run length matrices and Laws' texture energy measures) in discriminating malignant from benign tissue was investigated using a k-nearest neighbor classifier. Laws' texture energy measures achieved the best classification accuracy 89% (sensitivity 90.74% and specificity 86.96%).

  19. Can texture of tissue surrounding microcalcifications in mammography be used for breast cancer diagnosis?

    Energy Technology Data Exchange (ETDEWEB)

    Karahaliou, A.; Boniatis, I.; Sakellaropoulos, P.; Skiadopoulos, S.; Panayiotakis, G. [Department of Medical Physics, School of Medicine, University of Patras, Patras 265 00 (Greece); Costaridou, L. [Department of Medical Physics, School of Medicine, University of Patras, Patras 265 00 (Greece)], E-mail: costarid@upatras.gr

    2007-10-01

    This study investigates whether texture properties of the tissue surrounding microcalcifications (MCs) can contribute to breast cancer diagnosis. A case sample of 100 MC clusters (46 benign, 54 malignant) from 85 dense mammographic images included in the Digital Database for Screening Mammography, is analyzed. Regions of interest containing clusters are processed using wavelet-based enhancement and individual MCs are segmented by local thresholding. The segmented MCs are removed from original image data and the surrounding tissue area is subjected to texture analysis. The feasibility of four texture feature sets (first-order statistics, gray level co-occurrence matrices, gray level run length matrices and Laws' texture energy measures) in discriminating malignant from benign tissue was investigated using a k-nearest neighbor classifier. Laws' texture energy measures achieved the best classification accuracy 89% (sensitivity 90.74% and specificity 86.96%)

  20. HAM56 and CD68 antigen presenting cells surrounding a sarcoidal granulomatous tattoo

    Directory of Open Access Journals (Sweden)

    Ana Maria Abreu Velez

    2011-01-01

    Full Text Available Context : Tattoos are produced by introducing colorants of various compositions into the skin, either accidentally or for cosmetic purposes. Case Report: A 62-year-old male presented with a cosmetic tattoo and requested a total excision of the lesion. Dermatopathologic analysis of the excised tissue with hematoxylin and eosin examination, as well as immunohistochemistry was performed. H&E staining demonstrated classic histologic features of a tattoo. Utilizing immunohistochemistry, dermal histiocytic antigen presenting cells stained with HAM56 and CD68 antibodies; the staining was present surrounding the tattoo pigment. Conclusions : We identified two macrophage markers (HAM56 and CD68 surrounding dermal tattoo pigment. A minimal dermal inflammatory immune was noted to the tattoo pigment. Moreover, the immune response and/or tolerance to tattoos is not well characterized. We suggest that tattoo materials and techniques could be utilized in therapeutic delivery for diseases such recessive dystrophic epidermolysis bullosa, potentially preventing immune rejection of gene therapy agents.

  1. The Effects of GH Transgenic Goats on the Microflora of the Intestine, Feces and Surrounding Soil.

    Directory of Open Access Journals (Sweden)

    Zekun Bao

    Full Text Available The development of genetically engineered animals has brought with it increasing concerns about biosafety issues. We therefore evaluated the risks of growth hormone from transgenic goats, including the probability of horizontal gene transfer and the impact on the microbial community of the goats' gastrointestinal tracts, feces and the surrounding soil. The results showed that neither the GH nor the neoR gene could be detected in the samples. Moreover, there was no significant change in the microbial community of the gastrointestinal tracts, feces and soil, as tested with PCR-denaturing gradient gel electrophoresis and 16S rDNA sequencing. Finally, phylogenetic analysis showed that the intestinal content, feces and soil samples all contained the same dominant group of bacteria. These results demonstrated that expression of goat growth hormone in the mammary of GH transgenic goat does not influence the microflora of the intestine, feces and surrounding soil.

  2. Forest Fragments Surrounded by Sugar Cane Are More Inhospitable to Terrestrial Amphibian Abundance Than Fragments Surrounded by Pasture

    OpenAIRE

    Paula Eveline Ribeiro D’Anunciação; Marcela Fernandes Vilela Silva; Lucas Ferrante; Diego Santana Assis; Thamires Casagrande; Andréa Zalmora Garcia Coelho; Bárbara Christina Silva Amâncio; Túlio Ribeiral Pereira; Vinícius Xavier da Silva

    2013-01-01

    In recent years, there has been increasing interest in matrix-type influence on forest fragments. Terrestrial amphibians are good bioindicators for this kind of research because of low vagility and high philopatry. This study compared richness, abundance, and species composition of terrestrial amphibians through pitfall traps in two sets of semideciduous seasonal forest fragments in southeastern Brazil, according to the predominant surrounding matrix (sugar cane and pasture). There were no di...

  3. 氧化锆基台在种植体支持的全瓷修复中的应用%The application of zirconia abutment in implant supported all - ceramic restoration

    Institute of Scientific and Technical Information of China (English)

    王大山; 杨建军; 邓悦; 吴品林; 杨振; 杨凤丽; 张慧敏

    2011-01-01

    目的 探讨氧化锆基台的应用及种植体支持的全瓷修复体的临床效果.方法 选择安多键内连接种植系统φ4.0×10ram种植体植入缺牙区,上颌植入6个月、下颌植入3个月后安装自制的氧化锆基台;将基台予以磨改预留修复间隙,取印模,灌制石膏模型;应用CAD/CAM制作全瓷冠、桥;将全瓷修复体与基台粘接固位;应用MINRAY口内数字X线摄片系统和X线摄片定位仪,拍摄安装氧化锆基台时和全瓷修复体粘接后36个月时的X线片进行测量,对比分析.结果 自制的氧化锆基台能与种植体顺利装配,应用该基台和CAD/CAM制作的全瓷冠、桥修复体完成的15例患者18颗种植义齿全瓷修复的即刻效果满意,追踪30-36个月,所有患者的种植义齿使用良好,修复体和基台均无松动脱落与折裂、折断,牙周无炎症及牙槽骨吸收,部分患者的牙槽骨显示增高,患者满意度高.结论 应用氧化锆基台配合CAD/CAM氧化锆全瓷冠、桥修复体,不仅可获得满意的美学效果,还有益于种植义齿周围组织的健康.%Objective ThiS study is to discuss the application of zirconia abutment and Lhe clinical results of the implant supponed all - ceramic restoration.Methods Embed the Anthogyr inter - joins implant system ( φ 4.0 × 10mm)into the edentulous region, install the self - made zirconia abutment after 6 months maxilla implantation or 3 months mandible implantation; Then the abutment is ground to reserve restoration space and the impression is made to cast plaster mould; Make the all - ceramic crown/ bridge by CAD/CAM before adhere and fix the all - ceramic restoration with the abutment; Use MINRAY digital X - ray shooting system and X - ray holders system to shoot X - ray at the time of zirconia abutment installation and 36 months after the adhesion of the all - ceramic restoration then carry out measurement and comparative analysis.Results The self - made zirconia abutment can match well

  4. Induced radioactivity in a 4 MW target and its surroundings

    CERN Document Server

    Agosteo, Stefano; Otto, Thomas; Silari, Marco

    2003-01-01

    An important aspect of a future CERN Neutrino Factory is the material activation arising from a 2.2 GeV, 4 MW proton beam striking a mercury target. An estimation of the hadronic inelastic interactions and the production of residual nuclei in the target, the magnetic horn, the decay tunnel, the surrounding rock and a downstream dump was performed by the Monte Carlo hadronic cascade code FLUKA. The aim was both to assess the dose equivalent rate to be expected during maintenance work and to evaluate the amount of residual radioactivity, which will have to be disposed of after the facility has ceased operation.

  5. Recent underwater explorations at Dwarka and surroundings of Okha Mandal

    Digital Repository Service at National Institute of Oceanography (India)

    Gaur, A.S.; Sundaresh; Gudigar, P.; Tripati, S.; Vora, K.H.; Bandodkar, S.N.

    Mandal area: locations of onshore and offshore examples 68 Recent Underwater Explorations at Dwarka and Surroundings of Okha Mandal Fig. 2: Grapnel stone anchor in intertidal zone at Dwarka Diving operations were initiated from a convenient place... as there are no rope marks or marks of erosion. Offshore Explorations Diving operations were undertaken in an area of 1.6 km2 (22? 13' 27" to 22? 14' 08" N; 68? 57' 24" to 68? 58' 06" E). A total of 173 dives spanning over nearly 123 hours were carried out...

  6. Modeling pollutants dispersion in surrounding places to thermoelectric power plants

    International Nuclear Information System (INIS)

    In the Electrical Research Institute (IIE) have been carried out some studies on determination of concentration levels of atmospheric pollutants in areas where is located some thermoelectric central of the Electricity Federal Commission (CFE). These studies have as main objective to collect judgement elements that allow to take measurements for avoiding the environmental damage. At the present time it has been performed modelations of dispersion of atmospheric pollutants on surroundings of thermoelectric centrals, such as Lerdo, Manzanillo, Mazatlan, Monterrey, Rio Escondido, Salamanca, Mexico and Tula's Valley. Therefore in the present work has been included some generalities about the experiences gained in those studies. (Author)

  7. Failure mechanism of Mesozoic soft rock roadway in Shajihai coal mine and its surrounding rock control

    Institute of Scientific and Technical Information of China (English)

    Yuan Yue; Zhu Yongjian; Wang Weijun; Yu Weijian

    2014-01-01

    In view of the buckling failure caused by large deformation of Mesozoic soft rock roadway in Shajihai mining area, such as serious roof fall, rib spalling, floor heave, etc., based on the detail site investigation, theoretical analysis, mineral composition test, microstructure test, water-physical property test and field experiments were carried out. And we revealed the compound failure mechanism of Mesozoic soft rock roadway in Shajihai mining area, namely the molecule expansion-shear slip of weak structural plane-construction disturbance. On this basis, the coupling support technology whose core is constant resistance with large deformation bolt was proposed. The feature of this supporting technology is that a new type of structural composite material was used, which makes the supporting system not only has the ideal deformation characteristics, but also has high supporting resistance. Thus the fully release of plastic energy within surrounding rock and reasonable control of the thickness of the plastic ring were realized. Then the differential deformation between the surrounding rock and support was eliminated by the secondary coupling support of bolt–mesh–cable, and the bolt with high strength was applied in the base angle to control floor. Eventually the collaborative bearing system of surrounding rock–support was formed. Through field tests the validity and rationality of support was also verified.

  8. Biogeography of Timor and Surrounding Wallacean Islands: Endemism in Ants of the Genus Polyrhachis Fr. Smith

    Directory of Open Access Journals (Sweden)

    Colin R. Trainor

    2013-03-01

    Full Text Available The Wallacean island of Timor is of particular biological interest due to its relatively large size and transitional location between the Indo-Malayan and Australasian biogeographic realms. However, the origins and levels of endemism of its invertebrate fauna are poorly known. A recent study of Timorese ants revealed a diverse fauna with predominantly Indo-Malayan affinities, but species-level taxonomy was considered to be too poorly understood for an analysis of levels of endemism. The highly diverse Old World tropical genus Polyrhachis represents a notable exception, and here we analyse levels of endemism in the Polyrhachis fauna of Timor and surrounding islands. We supplement the species listed in the previous study with additional collections to record a total of 35 species of Polyrhachis from Timor and surrounding islands. Only 14 (40% of the 35 species could be named (P. constricta, P. costulata, P. gab, P. sokolova, P. hera, P. illaudata, P. rixosa, P. acantha chrysophanes, P. saevissima, P. bicolor, P. cryptoceroides, P. dives, P. longipes and P. olybria, and the large majority of the remaining species have not previously been collected. These are very likely to be endemic to Timor and surrounding islands, and point to remarkably high levels (>50% of endemism in the regional ant fauna.

  9. Removal of oxyfluorfen from spiked soils using electrokinetic soil flushing with the surrounding arrangements of electrodes.

    Science.gov (United States)

    Risco, C; Rubí-Juárez, H; Rodrigo, S; López-Vizcaíno, R; Saez, C; Cañizares, P; Barrera-Díaz, C; Navarro, V; Rodrigo, M A

    2016-07-15

    This work reports the results of a study in which the remediation of soil that undergoes an accidental discharge of oxyfluorfen is carried out by using electrokinetic soil flushing (EKSF). Two different electrode configurations were tested, consisting of several electrodes surrounding an electrode of different polarity (so-called 1A6C, one anode surrounded by six cathodes, and 1C6A, one cathode surrounded by six cathodes). A pilot plant scale was used (with a soil volume of 175dm(3)) to perform the studies. During the tests, different parameters were measured daily (flowrates, pH, electrical conductivity and herbicide concentration in different sampling positions). Furthermore, at the end of the test, a complete post-mortem analysis was carried out to obtain a 3-D map of the pollution, pH and electrical conductivity in the soil. The results demonstrate that electrode arrangement is a key factor for effective pollutant removal. In fact, the 1A6C configuration improves the removal rate by 41.3% versus the 27.0% obtained by the 1C6A configuration after a period of 35days. Finally, a bench mark comparison of this study of soil remediation polluted with 2,4-D allows for significant conclusions about the scale-up and full-scale application of this technology. PMID:27058128

  10. Stress variation of soil surrounding tunnel and grouting reinforcement effect based on stress release

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yin-tao; TAO Lian-jin; WANG Pei-lin; BIAN Jin

    2007-01-01

    With FLAC,a criteria of stress release ratio(SRR),i.e.,about 10% of the relative difference of the ground settlement before and after the supporting system is installed,is incorporated into stress release method(SRM).At the same time,the Mohr-Coulomb Criterion is used to analyze stress changes around the tunnel Induced by excavation.It shows that the surrounding soil around shallow tunnels can be partitioned by loosened zones(unloading zones)and plastic zones among which the shear stresses in the soil are less than 10 kPa below the M-C yield line.Both types of zones are separated.With the increasing of the SRR,the areas of plastic zones and loosen zones gradually increase.The surrounding soil is equally divided into 24 regions in order to study the Influence of different grouting regions on the ground settlement.The reinforcing effect of grouting can be modeled by enhancement of the soil strength around the tunnel.By the approach of the SRM,numericaI analysis indicates that,in the upper area(top of the surrounding soil about 210°),the reinforcing effect gradually decreases as the reinforcing region moves from arch springing to the vault of the crown;when reinforcing regions lie in the upside of the surrounding soil,the influence on the ground settlement is generally greater than in the lower part;at the same time,with the increase of the SRR,the influential differences are more and more obvious.

  11. TRIGGERED STAR FORMATION SURROUNDING WOLF-RAYET STAR HD 211853

    Energy Technology Data Exchange (ETDEWEB)

    Liu Tie; Wu Yuefang; Zhang Huawei [Department of Astronomy, Peking University, 100871 Beijing (China); Qin Shengli, E-mail: liutiepku@gmail.com [I. Physikalisches Institut, Universitaet zu Koeln, Zuelpicher Str. 77, 50937 Koeln (Germany)

    2012-05-20

    The environment surrounding Wolf-Rayet (W-R) star HD 211853 is studied in molecular, infrared, as well as radio, and H I emission. The molecular ring consists of well-separated cores, which have a volume density of 10{sup 3} cm{sup -3} and kinematic temperature {approx}20 K. Most of the cores are under gravitational collapse due to external pressure from the surrounding ionized gas. From the spectral energy distribution modeling toward the young stellar objects, the sequential star formation is revealed on a large scale in space spreading from the W-R star to the molecular ring. A small-scale sequential star formation is revealed toward core 'A', which harbors a very young star cluster. Triggered star formations are thus suggested. The presence of the photodissociation region, the fragmentation of the molecular ring, the collapse of the cores, and the large-scale sequential star formation indicate that the 'collect and collapse' process functions in this region. The star-forming activities in core 'A' seem to be affected by the 'radiation-driven implosion' process.

  12. Triggered star formation surrounding Wolf-Rayet star HD 211853

    CERN Document Server

    Liu, Tie; Zhang, Huawei; Qin, Sheng-Li

    2012-01-01

    The environment surrounding Wolf-Rayet star HD 211853 is studied in molecular emission, infrared emission, as well as radio and HI emission. The molecular ring consists of well-separated cores, which have a volume density of 10$^{3}$ cm$^{-3}$ and kinematic temperature $\\sim$20 K. Most of the cores are under gravitational collapse due to external pressure from the surrounding ionized gas. From SED modeling towards the young stellar objects (YSOs), sequential star formation is revealed on a large scale in space spreading from the Wolf-Rayet star to the molecular ring. A small scale sequential star formation is revealed towards core A, which harbors a very young star cluster. Triggered star formations is thus suggested. The presence of PDR, the fragmentation of the molecular ring, the collapse of the cores, the large scale sequential star formation indicate the "Collect and Collapse" process functions in this region. The star forming activities in core A seem to be affected by the "Radiation-Driven Implosion" (...

  13. Effectively Communicating the Uncertainties Surrounding Ebola Virus Transmission.

    Science.gov (United States)

    Kilianski, Andy; Evans, Nicholas G

    2015-10-01

    The current Ebola virus outbreak has highlighted the uncertainties surrounding many aspects of Ebola virus virology, including routes of transmission. The scientific community played a leading role during the outbreak-potentially, the largest of its kind-as many of the questions surrounding ebolaviruses have only been interrogated in the laboratory. Scientists provided an invaluable resource for clinicians, public health officials, policy makers, and the lay public in understanding the progress of Ebola virus disease and the continuing outbreak. Not all of the scientific communication, however, was accurate or effective. There were multiple instances of published articles during the height of the outbreak containing potentially misleading scientific language that spurred media overreaction and potentially jeopardized preparedness and policy decisions at critical points. Here, we use articles declaring the potential for airborne transmission of Ebola virus as a case study in the inaccurate reporting of basic science, and we provide recommendations for improving the communication about unknown aspects of disease during public health crises. PMID:26512988

  14. Implant-supported prostheses versus conventional permanent and removable dentures

    Directory of Open Access Journals (Sweden)

    Koszuta Agnieszka

    2014-06-01

    Full Text Available Social, economic and technological progress results in an increasing range of treatment and rehabilitation methods for patients with partial or complete edentulism. The role of the dentist is to inform the patient about the full range of available missing teeth treatment options leading to complete rehabilitation of the masticatory organ in agreement with the patient’s aesthetic and functional expectations. The aim of the paper was to identify the type of prostheses used by patients before opting for implantsupported teeth replacements, according to the patients’ age, sex, marital status, place of residence and education. The study covered 464 patients, women and men, aged 20-74, treated with dental implants. The patients answered questions in an anonymous questionnaire. The influence of the prosthetic replacement type according to age and marital status was highly statistically significant, whereas it was statistically significant according to sex, place of residence and education. The female respondents who previously used tissue-borne complete or partial dentures opted for implant treatment more frequently. The respondents younger than 40 and between 40-60 years of age who did not previously used any prosthetic replacements opted for implant treatment more frequently. The respondents who did not use any prosthetic replacements decided to undergo implant treatment most frequently, regardless of their marital status, education and place of residence. The patients opted for implant treatment to improve their quality of life, despite the high cost of such therapy.

  15. Implant-supported overdentures: a longitudinal prospective study.

    Science.gov (United States)

    Bergendal, T; Engquist, B

    1998-01-01

    The aim of this study was to evaluate the clinical function and long-term prognosis of overdentures retained by a small number of implants in the maxilla and mandible using one of two different attachment systems. Included in the study were all patients referred to specialty clinics in Jönköping and Linköping, Sweden, during the treatment period who needed an overdenture and could be provided with a minimum number of two bilaterally-placed implants. Excluded were patients with bone-grafted jaws, irradiated cancer patients, heavy bruxers, and patients who had lost a fixed prosthesis because of implant losses. The patients were randomly assigned to receive one retentive system, either a round 2-mm-diameter bar with clips or ball attachments (Nobel Biocare). Eighteen overdentures were placed in maxillae and 32 in mandibles, supported by a total of 115 Brånemark implants. Of the implants placed, 86.1% were continuously osseointegrated. The cumulative implant survival rates after 7 years of loading were 75.4% in the maxillae and 100% in the mandibles. There was no difference in implant survival rate between the attachment systems. Patients with implant losses were characterized by severely resorbed maxillary ridges and inferior bone quality, together with unfavorable loading circumstances such as short implants combined with long leverages. Complications and prosthetic adjustments were mostly resolved early and easily. PMID:9581412

  16. Solar Proton Transport within an ICRU Sphere Surrounded by a Complex Shield: Combinatorial Geometry

    Science.gov (United States)

    Wilson, John W.; Slaba, Tony C.; Badavi, Francis F.; Reddell, Brandon D.; Bahadori, Amir A.

    2015-01-01

    The 3DHZETRN code, with improved neutron and light ion (Z (is) less than 2) transport procedures, was recently developed and compared to Monte Carlo (MC) simulations using simplified spherical geometries. It was shown that 3DHZETRN agrees with the MC codes to the extent they agree with each other. In the present report, the 3DHZETRN code is extended to enable analysis in general combinatorial geometry. A more complex shielding structure with internal parts surrounding a tissue sphere is considered and compared against MC simulations. It is shown that even in the more complex geometry, 3DHZETRN agrees well with the MC codes and maintains a high degree of computational efficiency.

  17. The analysis of the characterstics of wind and wave fields over the surrounding waters of Taiwan Island using TOPEX satellite altimeter data%利用TOPEX卫星高度计资料分析台湾岛周边海域巨浪和大风特征

    Institute of Scientific and Technical Information of China (English)

    谢辛; 李燕初; 许德伟; 郑凌虹; 林明森

    2009-01-01

    卫星高度计实现了对全球性或区域性的海洋参量的实时监测,TOPEX卫星高度计提供了迄今为止时间序列最长、数据质量最高的全球海面风速和有效波高的同步观测资料.利用TOPEX卫星高度计资料,分析了有效波高4 m以上的巨浪在台湾岛周边海域的时空分布特征,结果表明台湾岛周边海域巨浪的分布具有明显的季节特征.每年平均有效波高最大值大多数出现在夏季,春季是1 a中有效波高最小的季节,而秋季和冬季是巨浪出现频率最高的季节.波高大干6 m的巨浪大都出现在台湾岛东部及东北部海域,在南部海域出现较少.%The satellite altimeter provides an efficient way for realtime monitoring global and regional oceanographic parameters.The TOPEX satellite altimeter has provided the synchronously observed data of the global sea surface wind speed and significant wave height(SWH), so far, these data have the longest time series and the best data quality. The data of the SWH and the wind speed over the surrounding waters of Taiwan Island are compared with the data from the TOPEX satellite altimeter,and the validity is analyzed from the TOPEX satellite altimeter data. Meanwhile, the characteristics of the SWH which is greater than or equal to 4 m over the surrounding waters of Taiwan Island is analyzed .It is shown that the large waves commonly appear in winter and autumn every year, and the maximum of the mean SWH often appears in summer, but it is opposite in spring. When the SWH is greater than or equal to 6 m, it appears in the surrounding waters of the east or northeast of Taiwan Island, and it less appears in the surrounding waters of the south of Taiwan Island.

  18. Rotation of the Warm Molecular Gas Surrounding Ultracompact HII Regions

    CERN Document Server

    Klaassen, P D; Keto, E R; Zhang, Q

    2009-01-01

    We present molecular line and 1.4 mm continuum observations towards five massive star forming regions at arcsecond resolution using the Submillimeter Array (SMA). We find that the warm molecular gas surrounding each HII region (as traced by SO_2 and OCS) appears to be undergoing bulk rotation. From the molecular line emission and thermal component of the continuum emission, we independently derived gas masses for each region which are consistent with each other. From the free-free component of the continuum emission we estimate the minimum stellar mass required to power the HII region and find that this mass, when added to the derived gas mass, is a significant fraction of the dynamical mass for that region.

  19. Ostwald ripening of the matrix phase surrounding dispersoids

    International Nuclear Information System (INIS)

    Self-similar coarsening of particles dispersed in a matrix is well known experimentally and theoretically as Ostwald ripening. In this paper we present experimental and numerical material on Cu-Co dispersions looking for the inverse effect: Does the copper matrix surrounding cobalt particles also coarsen self-similar during liquid phase sintering as the particles do? The experimental investigations were performed with Cu-Co alloys of various volume fractions of solid phase (0.25 to 0.7). Green compacts of both elemental powders were sintered at 1473 K for times between 5 minutes and 70 hours. The coarsening of the matrix was analysed in plane section of the specimens. The experimental results show that the matrix coarsens self-similar. A numerical modelling is presented clarifying the experimental results. (orig.)

  20. Casimir Effect in the Kerr Spacetime Surrounded by Quintessence

    CERN Document Server

    Bezerra, V B; Freitas, L F F; Muniz, C R

    2016-01-01

    We calculate the Casimir energy of a massless scalar field in a cavity formed by nearby parallel plates orbiting a rotating spherical body surrounded by quintessence, investigating the influence of the gravitational field on that energy, at zero temperature. This influence includes the effects due to the spacetime dragging caused by the source rotation as well as those ones due to the quintessence. We show that the energy depends on all the involved parameters, as source mass, angular momentum and quintessence state parameter, for any radial coordinate and polar angle. We show that at the north pole the Casimir energy is not influenced by the quintessential matter. At the equatorial plane, when the quintessence is canceled, the result obtained in the literature is recovered. Finally, constraints in the quintessence parameters are obtained from the uncertainty in the current measurements of Casimir effect.

  1. GPS constraints on the deformation of Azerbaijan and surrounding regions

    Science.gov (United States)

    Aktuğ, Bahadır; Meherremov, Elçin; Kurt, Mustafa; Özdemir, Soner; Esedov, Namaz; Lenk, Onur

    2013-07-01

    In this study, we present new GPS observations in Azerbaijan to provide an improved basis for determining the distribution of crustal deformation throughout the country and surrounding areas. The deformation field in the region has been analyzed with a dense GPS network configuration and a reliable quantification of the ongoing deformation was achieved. Results show that while contraction is dominant over the whole region, it is mostly concentrated on the middle and eastern parts of Caucasus Thrust Fault reaching up to 6.4 ± 0.2 mm/yr and Lesser Caucasus Fault does no accommodate more than 1-2 mm/yr of contraction. New network also clearly substantiates that the West Caspian Fault, which is a continuation of Caucasus Thrust Fault in the south, accommodates right-lateral slip rates of 7.1 ± 0.3 mm/yr in addition to 5.5 ± 0.3 mm/yr contraction rates.

  2. Wave rectification in plasma sheaths surrounding electric field antennas

    Science.gov (United States)

    Boehm, M. H.; Carlson, C. W.; Mcfadden, J. P.; Clemmons, J. H.; Ergun, R. E.; Mozer, F. S.

    1994-01-01

    Combined measurements of Langmuir or broadband whistler wave intensity and lower-frequency electric field waveforms, all at 10-microsecond time resolution, were made on several recent sounding rockets in the auroral ionosphere. It is found that Langmuir and whistler waves are partically rectified in the plasma sheaths surrounding the payload and the spheres used as antennas. This sheath rectification occurs whenever the high frequency (HF) potential across the sheath becomes of the same order as the electron temperature or higher, for wave frequencies near or above the ion plasma frequency. This rectification can introduce false low-frequency waves into measurements of electric field spectra when strong high-frequency waves are present. Second harmonic signals are also generated, although at much lower levels. The effect occurs in many different plasma conditions, primarily producing false waves at frequencies that are low enough for the antenna coupling to the plasma to be resistive.

  3. Kocaeli- Karamürsel- Yalakdere Town and Surrounding Flora

    Directory of Open Access Journals (Sweden)

    Meryem Sümeyye Yılancı

    2013-06-01

    Full Text Available In this study, Yalakdere (Karamürsel\\Kocaeli and the surrounding diversity of vascular plants were investigated. At the end of the field study which were conducted in the region, 712 plant specimens were collected. As a result of the diagnosis of these samples; 409 taxa included in 258 genera and 79 families were identified in research area. According to the taxa phytogeographic region distributions are as follows; 87 taxa the Euro- Siberian; 64 taxa Mediterranean; 7 taxa Iran –Turanian, 79 taxa of the multi phytogeographical region and 144 taxa unknown region.17 cultivated, 3 cosmopolitan, 7 endemic taxa were identified in the study area also the rate of endemism was 1,71 % in the region. Rhaponticoides pythiae ( Azn. ; Bornm. M.V.Agab. ; Greuter was collected which haven't been collected for a long time.

  4. Natural convection between a vertical cylinder and a surrounding array

    International Nuclear Information System (INIS)

    The generic situation considered is natural convection between a single heated, vertical cylinder and a surrounding array of cooler vertical cylinders in a triangular pattern. The ratio of the test section temperature to the cooling tube temperature was varied up to 2.6 by adjusting the electrical power. The Rayleigh number, based on test section diameter and air properties evaluated at cooling tube temperature, ranged from 2.9 x 104 to 4.6 x 105. Results indicate that the convective heat transfer data could be approximated as NuD (Tts/Tct)0.14 = 0.156 RaD1/3 in the apparent turbulent region for RaL > 1.2 x 1011

  5. Thermodynamic stability of black holes surrounded by quintessence

    CERN Document Server

    Ma, Meng-Sen; Ma, Ya-Qin

    2016-01-01

    We study the thermodynamic stabilities of uncharged and charged black holes surrounded by quintessence (BHQ) by means of effective thermodynamic quantities. When the state parameter of quintessence $\\omega_q$ is appropriately chosen, the structures of BHQ are something like that of black holes in de Sitter space. Constructing the effective first law of thermodynamics in two different ways, we can derive the effective thermodynamic quantities of BHQ. Especially, these effective thermodynamic quantities also satisfy Smarr-like formulae. It is found that the uncharged BHQ is always thermodynamically unstable due to negative heat capacity, while for the charged BHQ there are phase transitions of the second order. We also show that there is a great deal of difference on the thermodynamic properties and critical behaviors of BHQ between the two ways we employed.

  6. Earthquakes in Switzerland and surrounding regions during 2011

    International Nuclear Information System (INIS)

    This report of the Swiss Seismological Service summarizes the seismic activity in Switzerland and surrounding regions during 2011. During this period, 522 earthquakes and 92 quarry blasts were detected and located in the region under consideration. With a total of only 10 events with ML ≥ 2.5, the seismic activity in the year 2011 was far below the average over the previous 36 years. Most noteworthy were the earthquake sequence of Sierre (VS) in January, with two events of ML 3.3 and 3.2, the ML 3.3 earthquake at a depth of 31 km below Bregenz, and the ML 3.1 event near Delémont. The two strongest events near Sierre produced shaking of intensity IV. (authors)

  7. Language barriers surrounding medication use among older Latinos.

    Science.gov (United States)

    Mutchler, Jan E; Bacigalupe, Gonzalo; Coppin, Antonia; Gottlieb, Alison

    2007-03-01

    Limited English language proficiency forms a significant challenge for many Latinos in clinical settings. Although medications are commonly used by older individuals as a means of maintaining good health and managing health problems, the extent to which English proficiency is related to medication use among older Latinos is not known. Focus groups were conducted with Latino, community-residing individuals aged 50 and over in eastern Massachusetts. Qualitative evaluation of the group interviews suggests that language is a barrier in dealing with medication for these individuals. Limited English proficiency appears to be related to feelings of being discriminated against in clinical and pharmacy settings. As well, communicating directly with health professionals in a common language is associated with level of trust and confidence in medical settings. Use of formal and informal interpreters, as well as seeking Spanish-speaking physicians and pharmacies with Spanish-speaking staff, are identified as strategies for overcoming health-related obstacles surrounding language. PMID:17136455

  8. Natural convection between a vertical cylinder and a surrounding array

    Energy Technology Data Exchange (ETDEWEB)

    McEligot, D.M.; O' Brien, J.E.; Stoots, C.M.; Larson, T.K.; Christenson, W.A.; Mecham, D.C.; Lussie, W.G.

    1992-01-01

    The generic situation considered is natural convection between a single heated, vertical cylinder and a surrounding array of cooler vertical cylinders in a triangular pattern. The ratio of the test section temperature to the cooling tube temperature was varied up to 2.6 by adjusting the electrical power. The Rayleigh number, based on test section diameter and air properties evaluated at cooling tube temperature, ranged from 2.9 x 10{sup 4} to 4.6 x 10{sup 5}. Results indicate that the convective heat transfer data could be approximated as Nu{sub D} (T{sub ts}/T{sub ct}){sup 0.14} = 0.156 Ra{sub D}{sup 1/3} in the apparent turbulent region for Ra{sub L} > 1.2 x 10{sup 11.}

  9. Natural convection between a vertical cylinder and a surrounding array

    Energy Technology Data Exchange (ETDEWEB)

    McEligot, D.M.; O`Brien, J.E.; Stoots, C.M.; Larson, T.K.; Christenson, W.A.; Mecham, D.C.; Lussie, W.G.

    1992-09-01

    The generic situation considered is natural convection between a single heated, vertical cylinder and a surrounding array of cooler vertical cylinders in a triangular pattern. The ratio of the test section temperature to the cooling tube temperature was varied up to 2.6 by adjusting the electrical power. The Rayleigh number, based on test section diameter and air properties evaluated at cooling tube temperature, ranged from 2.9 x 10{sup 4} to 4.6 x 10{sup 5}. Results indicate that the convective heat transfer data could be approximated as Nu{sub D} (T{sub ts}/T{sub ct}){sup 0.14} = 0.156 Ra{sub D}{sup 1/3} in the apparent turbulent region for Ra{sub L} > 1.2 x 10{sup 11.}

  10. Teacher Leadership: Everyday Practices Surrounding Work- Related Stress

    Directory of Open Access Journals (Sweden)

    Chiweshe Nigel

    2015-06-01

    Full Text Available This interpretivist study contributes to our scholarly understanding of how everyday practices surrounding work-related stress in education affect teacher leadership and successful learning outcomes. Insights are drawn from our long-standing engagement in the field where we observed how teaching staff, students, and management interacted. These observations were supplemented by in-depth interviews with 20 teaching staff. Our findings reveal competing demands and practices across the individual intrapersonal environment and the work related environment. There were three key themes that emerged in answer to the core research question: 1 the role of relational practices in managing teacher burnout, 2 the role of surveillance practices in education and 3 the role of assimilating practices in education. Drawing insights from these practices, we develop a conceptual framework that will help us to see relations at work anew, and develop a deeper understanding of ‘sickies’, motivation, learning outcomes and teacher leadership opportunities in education

  11. The influence of different screw tightening forces on the vertical misfit of implant-supported frameworks Avaliação do efeito da força de aperto de parafusos de retenção na desadaptação marginal de próteses sobre implantes

    Directory of Open Access Journals (Sweden)

    Diego Klee de Vasconcellos

    2005-06-01

    Full Text Available OBJECTIVES: The present in vitro study was designed to compare the differences in the vertical misfit of implant-supported frameworks using three different forces for tightening the bridge locking screws: fastening by hand until first resistance, and using torque drivers with 10 and 20Ncm. METHODS: The investigation was conducted based on the results given by 9 six-unit nickel-chromium (2 abutments/ 4 pontics screw-retained implant-supported frameworks. The structures were exposed to simulated porcelain firings. The marginal misfit measurements were made using a traveling measuring microscope at selected screw tightening forces: fastening by hand until first resistance, and using torque drivers with 10 and 20Ncm. The results were submitted to one-way ANOVA with repeated measures on one factor, and post hoc pairwise comparisons using Tukey test (5%. RESULTS: The mean marginal misfit of the frameworks, fastening the screws by hand until first resistance, was 41.56µm (SD±12.45µm. The use of torque driver devices caused a significant reduction in marginal opening (pO presente estudo avaliou o efeito da força de aperto de parafusos de retenção na desadaptação marginal de próteses sobre implantes. A investigação foi conduzida baseada em resultados fornecidos por nove estruturas metálicas implanto-suportadas de seis elementos (02 retentores e 04 pônticos, retidas por parafusos. A mensuração da desadaptação marginal foi realizada com auxílio de microscópio óptico, nos seguintes momentos: M1: aperto com chave manual até a primeira resistência do parafuso; M2: aperto utilizando torquímetro mecânico com 10Ncm e M3: aperto utilizando torquímetro mecânico com 20Ncm. As médias de desadaptação foram submetidas à análise estatística (ANOVA e Tukey. O emprego de torquímetros mecânicos, independente do valor de torque, determinou redução significativa na abertura marginal (p<0,05. A desadaptação média na interface conex

  12. Zonal disintegration phenomenon in rock mass surrounding deep tunnels

    Institute of Scientific and Technical Information of China (English)

    WU Hao; FANG Qin; GUO Zhi-kun

    2008-01-01

    Zonal disintegration is a typical static phenomenon of deep rock masses. It has been defined as alternating regions of fractured and relatively intact rock mass that appear around or in front of the working stope during excavation of a deep tunnel. Zonal disintegration phenomenon was successfully demonstrated in the laboratory with 3D tests on analogous gypsum models, two circular cracked zones were observed in the test. The linear Mohr-Coulomb yield criterion was used with a constitutive model that showed linear softening and ideal residual plastic to analyze the elasto-plastic field of the enclosing rock mass around a deep tunnel. The results show that tunneling causes a maximum stress zone to appear between an elastic and plastic zone in the surrounding rock. The zonal disintegration phenomenon is analyzed by considering the stress-strain state of the rock mass in the vicinity of the maximum stress zone. Creep instability failure of the rock due to the development of the plastic zone, and transfer of the maximum stress zone into the rock mass, are the cause of zonal disintegration. An analytical criterion for the critical depth at which zonal disintegration can occur is derived. This depth depends mainly on the character and stress concentration coefficient of the rock mass.

  13. Dilemmas surrounding passive euthanasia--a Malaysian perspective.

    Science.gov (United States)

    Talib, Norchaya

    2005-09-01

    In western societies where the principle of autonomy is jealously guarded, perhaps active euthanasia is more often the focus of public concern and debates rather than any other forms of euthanasia. However due to the advance in technology and its corresponding ability in prolonging life, in Malaysia passive euthanasia presents more of a dilemma. For those concerned and involved with end of life decision-making, it is generally agreed that this is an area fraught with not only medical but legal and ethical issues. In Malaysia where the society is not homogenous but is multi-cultural and multi-religious, in addition to medical, legal and ethical issues, religious principles and cultural norms further impact and play significant roles in end of life decision-making. This paper seeks to identify the issues surrounding the practice of passive euthanasia in Malaysia. It will be shown that despite applicable legal provisions, current practice of the medical profession combined with religious and cultural values together affect decision-making which involves the withholding and/or withdrawing of life-saving treatment.

  14. An insight in the surroundings of HR4796

    CERN Document Server

    Lagrange, A -M; Boccaletti, A; Lacour, S; Thebault, P; Chauvin, G; Mouillet, D; Augereau, J C; Bonnefoy, M; Ehrenreich, D; Kral, Q

    2012-01-01

    HR4796 is a young, early A-type star harbouring a well structured debris disk, shaped as a ring with sharp inner edges. It forms with the M-type star HR4796B a binary system, with a proj. sep. ~560 AU. Our aim is to explore the surroundings of HR4796A and B, both in terms of extended or point-like structures. Adaptive optics images at L'-band were obtained with NaCo in Angular Differential Mode and with Sparse Aperture Masking (SAM). We analyse the data as well as the artefacts that can be produced by ADI reduction on an extended structure with a shape similar to that of HR4796A dust ring. We determine constraints on the presence of companions using SAM and ADI on HR4796A, and ADI on HR4796B. We also performed dynamical simulations of a disk of planetesimals and dust produced by collisions, perturbed by a planet located close to the disk outer edge. The disk ring around HR4796A is well resolved. We highlight the potential effects of ADI reduction of the observed disk shape and surface brightness distribution,...

  15. Dead discs, unstable discs and the stars they surround

    Directory of Open Access Journals (Sweden)

    D’Angelo Caroline

    2014-01-01

    Full Text Available Strong stellar magnetic fields significantly alter the behaviour of surrounding accretion discs. Recent work has demonstrated that at low accretion rates a large amount of mass can remain confined in the disc, contrary to the standard assumption that the magnetic field will expel the disc in an outflow (the “propeller regime”. These “dead discs” often become unstable, causing cycles of accretion onto the central star. Here I present the main predictions of this model, and argue that it provides a good explanation for the peculiar behaviour seen in several accreting sources with strong magnetic fields. I will focus in particular on three accreting millisecond X-ray pulsars: SAX J1808.4-3658, NGC 6440 X-2 and IGR J00291+5934. These sources all show low-frequency quasi-periodic oscillations consistent with a variable accretion rate, as well as unusual outburst patterns that suggest gas is confined in the inner disc regions during quiescence.

  16. Democratizing rendering for multiple viewers in surround VR systems

    KAUST Repository

    Schulze, Jürgen P.

    2012-03-01

    We present a new approach for how multiple users\\' views can be rendered in a surround virtual environment without using special multi-view hardware. It is based on the idea that different parts of the screen are often viewed by different users, so that they can be rendered from their own view point, or at least from a point closer to their view point than traditionally expected. The vast majority of 3D virtual reality systems are designed for one head-tracked user, and a number of passive viewers. Only the head tracked user gets to see the correct view of the scene, everybody else sees a distorted image. We reduce this problem by algorithmically democratizing the rendering view point among all tracked users. Researchers have proposed solutions for multiple tracked users, but most of them require major changes to the display hardware of the VR system, such as additional projectors or custom VR glasses. Our approach does not require additional hardware, except the ability to track each participating user. We propose three versions of our multi-viewer algorithm. Each of them balances image distortion and frame rate in different ways, making them more or less suitable for certain application scenarios. Our most sophisticated algorithm renders each pixel from its own, optimized camera perspective, which depends on all tracked users\\' head positions and orientations. © 2012 IEEE.

  17. Instability of Magnetized Ionization Fronts Surrounding H II Regions

    CERN Document Server

    Kim, Jeong-Gyu

    2014-01-01

    An ionization front (IF) surrounding an H II region is a sharp interface where a cold neutral gas makes transition to a warm ionized phase by absorbing UV photons from central stars. We investigate the instability of a plane-parallel D-type IF threaded by parallel magnetic fields, by neglecting the effects of recombination within the ionized gas. We find that weak D-type IFs always have the post-IF magnetosonic Mach number $\\mathcal{M}_{\\rm M2} \\leq 1$. For such fronts, magnetic fields increase the maximum propagation speed of the IFs, while reducing the expansion factor $\\alpha$ by a factor of $1+1/(2\\beta_1)$ compared to the unmagnetized case, with $\\beta_1$ denoting the plasma beta in the pre-IF region. IFs become unstable to distortional perturbations due to gas expansion across the fronts, exactly analogous to the Darrieus-Landau instability of ablation fronts in terrestrial flames. The growth rate of the IF instability is proportional linearly to the perturbation wavenumber as well as the upstream flow ...

  18. Mercury's interior, surface, and surrounding environment latest discoveries

    CERN Document Server

    Clark, Pamela Elizabeth

    2015-01-01

    This SpringerBrief details the MESSENGER Mission, the findings of which present challenges to widely held conventional views and remaining mysteries surrounding the planet. The work answers the question of why Mercury is so dense, and the implications from geochemical data on its planetary formation. It summarizes imaging and compositional data from the terrestrial planet surface processes and explains the geologic history of Mercury.  It also discusses the lack of southern hemisphere coverage. Our understanding of the planet Mercury has been in a transitional phase over the decades since Mariner 10. The influx of new data from the NASA MESSENGER Mission since it was inserted into the orbit of Mercury in March of 2011 has greatly accelerated that shift. The combined compositional data of relatively high volatiles (S, K), relatively low refractories (Al, Ca), and low crustal iron, combined with an active, partially molten iron rich core, has major implications for Mercury and Solar System formation. From a s...

  19. A large-scale shock surrounding a powerful radio galaxy

    CERN Document Server

    Croston, J H; Mingo, B; Evans, D A; Dicken, D; Morganti, R; Tadhunter, C N

    2010-01-01

    We report the Chandra detection of a large-scale shock, on scales of 200 kpc, in the cluster surrounding the powerful radio galaxy 3C 444 (PKS 2211-17). Our 20-ks Chandra observation allows us to identify a clear surface brightness drop around the outer edge of the radio galaxy, which is likely to correspond to a spheroidal shock propagating into the intracluster medium. We measure a temperature jump across the surface brightness drop of a factor ~1.7, which corresponds to a Mach number of ~1.7. This is likely to be an underestimate due to the need to average over a fairly large region when measuring the temperature of the post-shock gas. We also detect clear cavities corresponding to the positions of the radio lobes, which is only the second such detection associated with an FRII radio galaxy. We estimate that the total energy transferred to the environment is at least 8.2 x 10^60 ergs, corresponding to a jet power of >2.2 x 10^45 ergs s^-1 (assuming a timescale based on the measured shock speed). We also co...

  20. Tuning structure and mobility of solvation shells surrounding tracer additives.

    Science.gov (United States)

    Carmer, James; Jain, Avni; Bollinger, Jonathan A; van Swol, Frank; Truskett, Thomas M

    2015-03-28

    Molecular dynamics simulations and a stochastic Fokker-Planck equation based approach are used to illuminate how position-dependent solvent mobility near one or more tracer particle(s) is affected when tracer-solvent interactions are rationally modified to affect corresponding solvation structure. For tracers in a dense hard-sphere fluid, we compare two types of tracer-solvent interactions: (1) a hard-sphere-like interaction, and (2) a soft repulsion extending beyond the hard core designed via statistical mechanical theory to enhance tracer mobility at infinite dilution by suppressing coordination-shell structure [Carmer et al., Soft Matter 8, 4083-4089 (2012)]. For the latter case, we show that the mobility of surrounding solvent particles is also increased by addition of the soft repulsive interaction, which helps to rationalize the mechanism underlying the tracer's enhanced diffusivity. However, if multiple tracer surfaces are in closer proximity (as at higher tracer concentrations), similar interactions that disrupt local solvation structure instead suppress the position-dependent solvent dynamics. PMID:25833590

  1. Aeromagnetic map of Yucca Mountain and surrounding regions, southwest Nevada

    International Nuclear Information System (INIS)

    Magnetic anomalies over Yucca Mountain and surround areas are largely caused by variations in magnetic properties and shapes, including structural offsets, of the extensive volcanic units that underlie the region. In a few places the anomalies are caused by intrusions. Correlation between magnetic properties measured from rock samples and those derived from rock unit-magnetic anomaly associations is excellent. Anomaly characteristics, extensive magnetic gradients, and marked changes in the regional magnetic field can be coupled with the magnetic properties of the rock units to delineate structural boundaries. Three major boundaries are indicated by contrasts in regional magnetic expressions. Less extensive but more clearly indicated boundaries in the immediate vicinity of Yucca Mountain are interpreted from a distinctive pairing of northerly-displacement in generally gently dipping volcanic beds. The displacement between beds is located approximately along the border line between the linear anomaly pairs. One series of pairs of more northeasterly trend lies over the general location of a change from moderately thick to very thick volcanic units that was interpreted from gravity data. Several low amplitude but distinctively shaped anomalies in areas underlain primarily by sedimentary strata indicate the presence of intrusions and faults. 14 references, 2 figures

  2. Earthquake hypocenter relocation using double difference method in East Java and surrounding areas

    Science.gov (United States)

    C, Aprilia Puspita; Nugraha, Andri Dian; Puspito, Nanang T.

    2015-04-01

    Determination of precise hypocenter location is very important in order to provide information about subsurface fault plane and for seismic hazard analysis. In this study, we have relocated hypocenter earthquakes in Eastern part of Java and surrounding areas from local earthquake data catalog compiled by Meteorological, Climatological, and Geophysical Agency of Indonesia (MCGA) in time period 2009-2012 by using the double-difference method. The results show that after relocation processes, there are significantly changes in position and orientation of earthquake hypocenter which is correlated with the geological setting in this region. We observed indication of double seismic zone at depths of 70-120 km within the subducting slab in south of eastern part of Java region. Our results will provide useful information for advance seismological studies and seismic hazard analysis in this study.

  3. Earthquake hypocenter relocation using double difference method in East Java and surrounding areas

    International Nuclear Information System (INIS)

    Determination of precise hypocenter location is very important in order to provide information about subsurface fault plane and for seismic hazard analysis. In this study, we have relocated hypocenter earthquakes in Eastern part of Java and surrounding areas from local earthquake data catalog compiled by Meteorological, Climatological, and Geophysical Agency of Indonesia (MCGA) in time period 2009-2012 by using the double-difference method. The results show that after relocation processes, there are significantly changes in position and orientation of earthquake hypocenter which is correlated with the geological setting in this region. We observed indication of double seismic zone at depths of 70-120 km within the subducting slab in south of eastern part of Java region. Our results will provide useful information for advance seismological studies and seismic hazard analysis in this study

  4. Earthquake hypocenter relocation using double difference method in East Java and surrounding areas

    Energy Technology Data Exchange (ETDEWEB)

    C, Aprilia Puspita [Geophysical Engineering Program, Faculty of Mining and Petroleum Engineering, Institute of Technology Bandung (Indonesia); Meteorological, Climatological, and Geophysical Agency (MCGA) of Indonesian, Jakarta (Indonesia); Nugraha, Andri Dian, E-mail: nugraha@gf.itb.ac.id [Geophysical Engineering Program, Faculty of Mining and Petroleum Engineering, Institute of Technology Bandung (Indonesia); Puspito, Nanang T [Global Geophysical Research Group, Faculty of Mining and Petroleum Engineering, Institute of Technology Bandung (Indonesia)

    2015-04-24

    Determination of precise hypocenter location is very important in order to provide information about subsurface fault plane and for seismic hazard analysis. In this study, we have relocated hypocenter earthquakes in Eastern part of Java and surrounding areas from local earthquake data catalog compiled by Meteorological, Climatological, and Geophysical Agency of Indonesia (MCGA) in time period 2009-2012 by using the double-difference method. The results show that after relocation processes, there are significantly changes in position and orientation of earthquake hypocenter which is correlated with the geological setting in this region. We observed indication of double seismic zone at depths of 70-120 km within the subducting slab in south of eastern part of Java region. Our results will provide useful information for advance seismological studies and seismic hazard analysis in this study.

  5. Stability assessment of rock surrounding an I-beam supported retreating roadway

    Institute of Scientific and Technical Information of China (English)

    严红; 张吉雄; 李林玥; 冯锐敏

    2015-01-01

    The installation of a back-wall guard-board is the key to successfully supporting underground retreating roadways in coal mines. Based on the coordinate support principle, and using an I-shaped steel support for the surrounding rock, a mechanical model was developed for the stability of the roadway support and surrounding rock. Analysis of the bearing capacity of the roof back-wall guard-board and modelling of the equations for the maximum deflection and the maximum compressive stress of the top and side beams of the I-shaped steel support were undertaken. Simultaneously, the model was used to calculate and analyse the stability of the top and side beams of the I-shaped steel support structure and analyse the criteria for their stability. The results provide a reliable theoretical basis for the judgment of the stability of the surrounding rock and support structure. The theoretical evaluation results are consistent with field data. Finally, the key support parameters of the top and side beams of the I-shaped steel support structure and the variation of the maximum deflection and the maximum compressive stress as affected by the influence of the guard-board length were investigated. It is concluded that, as the back-board length increases, the maximum compressive stress in the top beam of the I-shaped steel support increases while the compressive stress in the side beam decreases. The results show that the accuracy of judgment of the stability of a supported retreating roadway is improved, providing guidance for the design of such typical I-shaped steel support and back-board structures.

  6. A Study on Soil and Groundwater Pollution Remediation of the Surrounding Real Estate Prices and Tax Revenue Impact

    Directory of Open Access Journals (Sweden)

    Chia-Nung Li

    2015-11-01

    Full Text Available To see whether the surrounding real estate price after soil and groundwater pollution remediation will revert to the level before the risk of implicit pollution, this paper uses research methods, such as the hedonic price method and contingent valuation method for analysis. The results of empirical analysis reveal that the hedonic price method will be restricted by trade cases around pollution sites. In view of this, it proposes using the contingent valuation method and consumers’ viewpoints for the analysis. Empirical results show that after pollution remediation the respondents are willing to pay an average of $1168 per square meter, which is slightly higher than the current price of $1059 per square meter with an increase of about 10%. Therefore, prices will recover after remediation at least to the level of the surrounding area.

  7. Cholinergic enhancement reduces orientation-specific surround suppression but not visual crowding

    OpenAIRE

    Kosovicheva, Anna A.; Sheremata, Summer L; Ariel eRokem; Landau, Ayelet N; Silver, Michael A.

    2012-01-01

    Acetylcholine (ACh) reduces the spatial spread of excitatory fMRI responses in early visual cortex and the receptive field sizes of V1 neurons. We investigated the perceptual consequences of these physiological effects of ACh with surround suppression and crowding, two tasks that involve spatial interactions between visual field locations. Surround suppression refers to the reduction in perceived stimulus contrast by a high-contrast surround stimulus. For grating stimuli, surround suppression...

  8. Linking student performance in Massachusetts elementary schools with the "greenness" of school surroundings using remote sensing.

    Directory of Open Access Journals (Sweden)

    Chih-Da Wu

    Full Text Available Various studies have reported the physical and mental health benefits from exposure to "green" neighborhoods, such as proximity to neighborhoods with trees and vegetation. However, no studies have explicitly assessed the association between exposure to "green" surroundings and cognitive function in terms of student academic performance. This study investigated the association between the "greenness" of the area surrounding a Massachusetts public elementary school and the academic achievement of the school's student body based on standardized tests with an ecological setting. Researchers used the composite school-based performance scores generated by the Massachusetts Comprehensive Assessment System (MCAS to measure the percentage of 3rd-grade students (the first year of standardized testing for 8-9 years-old children in public school, who scored "Above Proficient" (AP in English and Mathematics tests (Note: Individual student scores are not publically available. The MCAS results are comparable year to year thanks to an equating process. Researchers included test results from 2006 through 2012 in 905 public schools and adjusted for differences between schools in the final analysis according to race, gender, English as a second language (proxy for ethnicity and language facility, parent income, student-teacher ratio, and school attendance. Surrounding greenness of each school was measured using satellite images converted into the Normalized Difference Vegetation Index (NDVI in March, July and October of each year according to a 250-meter, 500-meter, 1,000-meter, and 2000-meter circular buffer around each school. Spatial Generalized Linear Mixed Models (GLMMs estimated the impacts of surrounding greenness on school-based performance. Overall the study results supported a relationship between the "greenness" of the school area and the school-wide academic performance. Interestingly, the results showed a consistently positive significant association

  9. Experimental study on stability control technology of surrounding rock of deep roadways in coal mine

    Institute of Scientific and Technical Information of China (English)

    Luo Yong; Yuan Liang; Yang Yang

    2014-01-01

    In order to solve effectively the problems of deep mining with safety and high efficiency,the multi-ple factors influencing the stability of deep rock roadway and technical problems are analyzed in the light of the severe situation of effective mining for deep coal resource,and the stability control methods for deep rock road-way are provided,which are based on the idea of combined support with separated steps and integral control of surrounding rock of deep rock roadway. The suggested methods were applied to a deep rock roadway with-648 m depth in Gubei coal mine of Huainan area. The field test was carried out and the in-situ monitoring was imple-mented,and the support scheme was optimized and adjusted to improve the stability of the surrounding rock of the roadway based on the feedback analysis. The results showed that the stability can be improved greatly by the provided control methods for deep roadway. The present methods for stability control of deep rock roadway can be used to other deep rock roadways with the similar conditions.

  10. Chaotic time series prediction for surrounding rock's deformation of deep mine lanes in soft rock

    Institute of Scientific and Technical Information of China (English)

    LI Xi-bing; WANG Qi-sheng; YAO Jin-rui; ZHAO Guo-yan

    2008-01-01

    Based on the measured displacements, the change laws of the effect of distance in phase space on the deformation of mine lane were analyzed and the chaotic time series model to predict the surrounding rocks deformation of deep mine lane in soft rock by nonlinear theory and methods was established. The chaotic attractor dimension(D) and the largest Lyapunov index(Emax) were put forward to determine whether the deformation process of mine lane is chaotic and the degree of chaos. The analysis of examples indicates that when D>2 and Emax>0, the surrounding rock's deformation of deep mine lane in soft rock is the chaotic process and the laws of the deformation can still be well demonstrated by the method of the reconstructive state space. Comparing with the prediction of linear time series and grey prediction, the chaotic time series prediction has higher accuracy and the prediction results can provide theoretical basis for reasonable support of mine lane in soft rock. The time of the second support in Maluping Mine of Guizhou, China, is determined to arrange at about 40 d after the initial support according to the prediction results.

  11. Different responses of different altitudes surrounding Taklimankan Desert to global climate change

    Science.gov (United States)

    Chongyi, E.; Yong, Wang; Taibao, Yang; Jiankang, Han; Hongchang, Hu; Fengmei, Yang

    2009-02-01

    Chongce Ice Cap (35°14'N, 81°07'E), located in the south margin of Taklimakan Desert, West Kunlun Mts. of China was sampled by coring in 1992, and this provides us with climate proxy of high altitudes (6,530 m). Through analyzing the weather observation stations surrounding Taklimakan Desert, the climate record of Hotan station was chosen to be the representative of low altitudes. Wavelet analysis were used to investigate the climatic variations of patterns, cycles and frequencies of different altitudes from 1954 to 1992, and different responses of different altitude surrounding Taklimakan Desert to global warming were recorded: (1) coherent decline of snow accumulation rate and dust deposition of high altitude recorded in Chongce ice core; (2) coherent increase of summer half-year precipitation and SAT of Hotan; (3) consistent variation tendency between dust deposit recorded in Chongce ice core and Hotan spring sandstorm days; (4) opposite variation tendency between Hotan precipitation and Chongce ice core snow accumulation rate and consistent cycles in general. By analyzing the mechanism of different responses, the predominant factors were determined of different altitudes: (1) at the low altitude, the vapor supply is predominant, and more vapor supplying means more precipitation; (2) at the high altitude, probably the population of dust aerosols which act as cloud ice nuclei in high altitude takes advantage over the vapor supply to affect the precipitation, and so the dust aerosol population reducing results in the wet deposition being reduced, thus the dust aerosol is the predominant factor.

  12. Clinical Observation of Vascular Dementia Treated by Surrounding-acupuncture of the CT-located Area

    Institute of Scientific and Technical Information of China (English)

    LUN Xin; FENG Bi-fang; RONG Li; YANG Wen-hui

    2003-01-01

    Purpose To observe the clinical effect of "Surrounding Needling Technigue through CT Location" in treating vascular dementia. Method Fifty cases of vascular dementia were randomly divided into surrounding Needling Technigue through CT location and routine acupuncture groups, 25 cases in each group,and were given surrounding Needling Technigue through CT location and routine acupuncture respectively. Results The effective rates in surrounding Needling Technigue through CT location and routine acupuncture groups were 88% and 60% respectively, and there was significant difference between the two groups, P < 0.01.Conclusion Therapeutic effect of surrounding Needling Technigue through CT location in treating vascular dementia was satisfactory, and better than that of routine acupuncture.

  13. Circumstances surrounding dying in the paediatric intensive care unit

    Directory of Open Access Journals (Sweden)

    Plötz Frans B

    2006-08-01

    Full Text Available Abstract Background Death is inevitable in the paediatric intensive care unit (PICU. We aimed to describe the circumstances surrounding dying in a PICU. Method The chart records of all patients less than 18 years of age who died at the PICU between January first 2000 and July first 2005 were retrospectively analyzed. Information regarding sex, age, length of stay, admission, diagnosis, and the way a patient died was registered. Post mortem information regarding natural versus unnatural death, autopsy and donation was obtained. Non-survivors were allocated in five groups: do-not-resuscitate (DNR, withholding and/or withdrawal of therapy (W/W, failed cardiopulmonary resuscitation (failed CPR, brain death (BD, and terminal organ failure (TOF. Results During the study period 87 (4.4% of the 1995 admitted patients died. Non-survivors were more often admitted during the day (54% and the week (68%. W/W was found in 27.6%, TOF in 26.4%, BD in 23.0%, failed CPR in 18.4%, and DNR in 4.6%. Forty-three percent died in the first two days, of which BD (40.5% and failed CPR (37.8% were most common. Seventy-five children (86% died due to a natural cause. Autopsy permission was obtained in 19 of 54 patients (35%. The autopsies confirmed the clinical diagnosis in 11 patients, revealed new information in 5 patients, and in 3 patients the autopsy did not provide additional information. Nine patients were medically suitable for organ donation and 24 patients for tissue donation, whereas consent was only obtained in 2 cases in both groups. Conclusion We observed that 43% of the patients died within the first two days of admission due to BD and failed CPR, whereas after 4 days most patients died after W/W. Autopsy remains an useful tool to confirm clinical diagnoses or to provide new information. Only a small percentage of the deceased children is suitable for organ donation.

  14. Behavioural aspects surrounding medicine purchases from pharmacies in Australia

    Directory of Open Access Journals (Sweden)

    Emmerton L

    2008-09-01

    Full Text Available Objective: This study aimed to produce current data regarding behavioural aspects of non-prescription (over-the-counter medicine purchases, in light of changes in the pharmaceutical market and increasing provision of professional services in pharmacies.Methods: Data were collected in 15 community pharmacies in South-East Queensland, Australia, over 540 hours in five days in August, 2006. The method, previously validated, involved documentation of both observational and interview data. Fifteen trained researchers were stationed in a selected pharmacy each to unobtrusively observe all eligible sales of non-prescription medicines, and, where possible, interview the purchasers post-sale. Non-response was supplemented by observational data and recall by the salesperson. The data included details of the purchase and purchasing behaviour, while new questions addressed issues of topical importance, including customers’ privacy concerns. A selection of the analyses is reported here.Results: In total, 3470 purchases were documented (135-479 per pharmacy, with customers of 67.5% of purchases (74.7% excluding an outlier pharmacy participating in the survey. Customers averaged 1.2 non-prescription medicines per transaction. Two-thirds (67.2% of customers were female, and 38.8% of the customers were aged 31-45 years. Analgesics and respiratory medicines accounted for two-thirds of the sales data (33.4% and 32.4%, respectively. Intended-brand purchases comprised 71% of purchases (2004/2824; in-store substitution then occurred in 8.8% of these cases, mainly following recommendations by pharmacy staff. Medicines intended for self-use comprised 62.9% of purchases (1752/2785. First-time purchases (30.8%, 799/2594 were more commonly influenced by pharmacy staff than by advertising.Conclusions: This study used validated methods adapted to a changing marketplace, thus providing data that both confirm and add to knowledge surrounding medicine purchases. Despite the

  15. Highly Enriched Uranium Metal Cylinders Surrounded by Various Reflector Materials

    Energy Technology Data Exchange (ETDEWEB)

    Bernard Jones; J. Blair Briggs; Leland Monteirth

    2007-05-01

    A series of experiments was performed at Los Alamos Scientific Laboratory in 1958 to determine critical masses of cylinders of Oralloy (Oy) reflected by a number of materials. The experiments were all performed on the Comet Universal Critical Assembly Machine, and consisted of discs of highly enriched uranium (93.3 wt.% 235U) reflected by half-inch and one-inch-thick cylindrical shells of various reflector materials. The experiments were performed by members of Group N-2, particularly K. W. Gallup, G. E. Hansen, H. C. Paxton, and R. H. White. This experiment was intended to ascertain critical masses for criticality safety purposes, as well as to compare neutron transport cross sections to those obtained from danger coefficient measurements with the Topsy Oralloy-Tuballoy reflected and Godiva unreflected critical assemblies. The reflector materials examined in this series of experiments are as follows: magnesium, titanium, aluminum, graphite, mild steel, nickel, copper, cobalt, molybdenum, natural uranium, tungsten, beryllium, aluminum oxide, molybdenum carbide, and polythene (polyethylene). Also included are two special configurations of composite beryllium and iron reflectors. Analyses were performed in which uncertainty associated with six different parameters was evaluated; namely, extrapolation to the uranium critical mass, uranium density, 235U enrichment, reflector density, reflector thickness, and reflector impurities. In addition to the idealizations made by the experimenters (removal of the platen and diaphragm), two simplifications were also made to the benchmark models that resulted in a small bias and additional uncertainty. First of all, since impurities in core and reflector materials are only estimated, they are not included in the benchmark models. Secondly, the room, support structure, and other possible surrounding equipment were not included in the model. Bias values that result from these two simplifications were determined and associated

  16. A comparison of stress distribution and flexion among various designs of bar attachments for implant overdentures: A three dimensional finite element analysis

    OpenAIRE

    Prakash Vijay; D′Souza Mariette; Adhikari Raviraj

    2009-01-01

    Context: Bar overdentures are popular choices among clinicians worldwide but configurations that provide an optimal biomechanical distribution of stress are still debatable. Aims: To compare the stresses and elastic flexion between implant supported bar overdentures in various configurations using finite element analysis. Settings and Design: A CAT scan of a human mandible was used to generate an anatomically accurate mechanical model. Materials and Methods: Three models with bars an...

  17. Laser-induced fluorescence and reflectance spectroscopy for the discrimination of basal cell carcinoma from the surrounding normal skin tissue.

    Science.gov (United States)

    Drakaki, E; Kaselouris, E; Makropoulou, M; Serafetinides, A A; Tsenga, A; Stratigos, A J; Katsambas, A D; Antoniou, C

    2009-01-01

    The object of this study was to investigate whether laser-induced skin autofluorescence (LIF) and/or light reflectance spectra could provide a useful contrast between basal cell carcinoma (BCC) tissues and the surrounding healthy skin. Unstained human skin samples, excised from humans undergoing biopsy examination, were irradiated with a nitrogen laser (lambda = 337 nm) for excitation of autofluorescence and a tungsten halogen lamp for the reflectance measurements. The ex vivo spectroscopic results were correlated with the histopathology images to distinguish the areas of BCC from those of the surrounding health skin. A simple spectral analysis technique was also applied for better skin diagnosis. In conclusion, it seems that LIF and reflectance spectra could be used to differentiate neoplastic from normal skin tissue using an appropriate classification model analysis. PMID:19365155

  18. 2010-2011年海口及周边地区3248例学龄前儿童血铅检测与分析%Analysis on blood lead detection in 3 248 children in Haikou City and the surrounding areas

    Institute of Scientific and Technical Information of China (English)

    付姣; 庞海云; 黄白丽; 阮和球

    2012-01-01

    目的 了解海口及周边地区6岁以下儿童血铅水平分布情况,为预防儿童铅中毒提供依据.方法 使用石墨炉原子吸收光谱法测定2010年7月至2011年6月本院3 248例6岁以下儿童的血铅水平,并分别对不同年龄和性别儿童的血铅平均水平和铅中毒发生率进行统计分析.结果 儿童血铅总体均值为44.315 μg/L,其中男童的血铅均值为44.400 μg L,女童的血铅均值为44.171 μg/L;血铅≥100μg/L的儿童共46例,占1.42%,其中男性27例,超标率为1.32%,女性19例,超标率为1.58%.不同年龄组和不同性别儿童血铅均值及铅中毒检出率差异均无统计学意义.结论 海口及周边地区儿童血铅水平及铅中毒率比国内平均水平低,但血铅水平受居住场所、生活卫生习惯等多种因素影响较大,故全社会和相关部门仍应重视血铅的防治.%Objective To investigate the blood lead detection of children in Haikou and the surrounding areas, and to provide scientific guidance for the prevention of lead poisoning in children. Methods The concentration of lead was determined using graphite furnace atomic absorption spectrophotometer in 3 248 blood samples of children from the Hainan Provincial People's Hospital from July 2010 to June 2011. The mean levels of blood lead and the rate of lead poisoning were analyzed. Results The mean level of blood lead was 44.315 μg/L in the 3 248 children, which was 44.400 μg/L in boys and 44.171 ug/L in girls. 46 cases were found with no less than 100 μg/L blood lead (1.41%), including 27 boys (1.32%) and 19 girls (1.57%). The mean level of blood lead and the rate of lead poisoning showed no statistically significant differences in children of different ages and gender. Conclusion The mean level of blood lead and the rate of lead poisoning in Haikou and the surrounding areas is lower than the national average level. The level of blood lead is influenced by the habitat, living habits and other

  19. 武汉市及周边地区儿童2006至2008年血铅水平及趋势分析%Analysis and its trend of blood lead level of children in Wuhan and the surrounding areas from 2006 to 2008

    Institute of Scientific and Technical Information of China (English)

    刘瑜; 艾洪武; 曾叶; 刘秀珍; 余小红

    2011-01-01

    Objective To analyze the blood lead level of different-aged children and the trend to change in Wuhan and the surrounding areas from 2006 to 2008.Methods The lead content in peripheral blood of 24 980 children was determined by wolfram atomic absorption spectrometer.The children were classified into several groups by age in different forms, and the data were analyzed statistically.Results The mean blood lead level of 24 980 children from Wuhan and the surrounding areas was 58.26 μg/L.Among them, the average blood lead in boys (60.12 μg/L) was higher than girls (54.24 μg/L).The average blood lead levels of the children in year 2006, 2007 and 2008 were (67.51 ± 31.02 ), (60.97 ± 32.58 ) and ( 50.32 ± 31.02 ) μg/L, respectively.In different age groups, the blood lead level in boys was higher than that in girls.In blood lead levels of 24 980 children,44.51% of children accounted for less than 50 μg/L,48.13% accounted for 51-100 μg/L,6.68% accounted for 101-200 μg/L,and 0.68% accounted for 201 μg/L or more.7.35% of the children were found with blood lead level ≥ 100 μg/L.In year 2006, 2007 and 2008, blood lead poisoning rates of the children were 15.88%, 7.74% and 2.13%, respectively.In addition,compared with children in outpatients, children with health examination had lower blood lead levels ( P < 0.05 ).Conclusions From 2006 to 2008, children's blood lead levels and lead poisoning rates in Wuhan and the surrounding areas have annually decreased, and the trend to descend is remarkable in 2008.%目的 分析2006至2008年武汉市及周边地区不同年龄儿童血铅水平状况及变化趋势.方法 采用钨舟原子吸收光谱法对24 980名儿童手指末捎血进行铅含量检测.对受检儿童按年龄进行不同形式的分组,并对检测结果 进行分析.结果 武汉市及周边地区儿童血铅总体水平为58.26 μg/L.其中,男童血铅水平为60.12 μg/L,高于女童(54.24 μg/L).2006至2008年

  20. Supplement: The Rate of Binary Black Hole Mergers Inferred from Advanced LIGO Observations Surrounding GW150914

    CERN Document Server

    Abbott, B P; Abbott, T D; Abernathy, M R; Acernese, F; Ackley, K; Adams, C; Adams, T; Addesso, P; Adhikari, R X; Adya, V B; Affeldt, C; Agathos, M; Agatsuma, K; Aggarwal, N; Aguiar, O D; Aiello, L; Ain, A; Ajith, P; Allen, B; Allocca, A; Altin, P A; Anderson, S B; Anderson, W G; Arai, K; Araya, M C; Arceneaux, C C; Areeda, J S; Arnaud, N; Arun, K G; Ascenzi, S; Ashton, G; Ast, M; Aston, S M; Astone, P; Aufmuth, P; Aulbert, C; Babak, S; Bacon, P; Bader, M K M; Baker, P T; Baldaccini, F; Ballardin, G; Ballmer, S W; Barayoga, J C; Barclay, S E; Barish, B C; Barker, D; Barone, F; Barr, B; Barsotti, L; Barsuglia, M; Barta, D; Bartlett, J; Bartos, I; Bassiri, R; Basti, A; Batch, J C; Baune, C; Bavigadda, V; Bazzan, M; Behnke, B; Bejger, M; Bell, A S; Bell, C J; Berger, B K; Bergman, J; Bergmann, G; Berry, C P L; Bersanetti, D; Bertolini, A; Betzwieser, J; Bhagwat, S; Bhandare, R; Bilenko, I A; Billingsley, G; Birch, J; Birney, R; Biscans, S; Bisht, A; Bitossi, M; Biwer, C; Bizouard, M A; Blackburn, J K; Blair, C D; Blair, D G; Blair, R M; Bloemen, S; Bock, O; Bodiya, T P; Boer, M; Bogaert, G; Bogan, C; Bohe, A; Bojtos, P; Bond, C; Bondu, F; Bonnand, R; Boom, B A; Bork, R; Boschi, V; Bose, S; Bouffanais, Y; Bozzi, A; Bradaschia, C; Brady, P R; Braginsky, V B; Branchesi, M; Brau, J E; Briant, T; Brillet, A; Brinkmann, M; Brisson, V; Brockill, P; Brooks, A F; Brown, D A; Brown, D D; Brown, N M; Buchanan, C C; Buikema, A; Bulik, T; Bulten, H J; Buonanno, A; Buskulic, D; Buy, C; Byer, R L; Cadonati, L; Cagnoli, G; Cahillane, C; Bustillo, J Calder'on; Callister, T; Calloni, E; Camp, J B; Cannon, K C; Cao, J; Capano, C D; Capocasa, E; Carbognani, F; Caride, S; Diaz, J Casanueva; Casentini, C; Caudill, S; Cavagli`a, M; Cavalier, F; Cavalieri, R; Cella, G; Cepeda, C B; Baiardi, L Cerboni; Cerretani, G; Cesarini, E; Chakraborty, R; Chalermsongsak, T; Chamberlin, S J; Chan, M; Chao, S; Charlton, P; Chassande-Mottin, E; Chen, H Y; Chen, Y; Cheng, C; Chincarini, A; Chiummo, A; Cho, H S; Cho, M; Chow, J H; Christensen, N; Chu, Q; Chua, S; Chung, S; Ciani, G; Clara, F; Clark, J A; Cleva, F; Coccia, E; Cohadon, P -F; Colla, A; Collette, C G; Cominsky, L; Constancio, M; Conte, A; Conti, L; Cook, D; Corbitt, T R; Cornish, N; Corsi, A; Cortese, S; Costa, C A; Coughlin, M W; Coughlin, S B; Coulon, J -P; Countryman, S T; Couvares, P; Cowan, E E; Coward, D M; Cowart, M J; Coyne, D C; Coyne, R; Craig, K; Creighton, J D E; Cripe, J; Crowder, S G; Cumming, A; Cunningham, L; Cuoco, E; Canton, T Dal; Danilishin, S L; D'Antonio, S; Danzmann, K; Darman, N S; Dattilo, V; Dave, I; Daveloza, H P; Davier, M; Davies, G S; Daw, E J; Day, R; De, S; DeBra, D; Debreczeni, G; Degallaix, J; De Laurentis, M; Del'eglise, S; Del Pozzo, W; Denker, T; Dent, T; Dereli, H; Dergachev, V; De Rosa, R; DeRosa, R T; DeSalvo, R; Dhurandhar, S; D'iaz, M C; Di Fiore, L; Di Giovanni, M; Di Lieto, A; Di Pace, S; Di Palma, I; Di Virgilio, A; Dojcinoski, G; Dolique, V; Donovan, F; Dooley, K L; Doravari, S; Douglas, R; Downes, T P; Drago, M; Drever, R W P; Driggers, J C; Du, Z; Ducrot, M; Dwyer, S E; Edo, T B; Edwards, M C; Effler, A; Eggenstein, H -B; Ehrens, P; Eichholz, J; Eikenberry, S S; Engels, W; Essick, R C; Etzel, T; Evans, M; Evans, T M; Everett, R; Factourovich, M; Fafone, V; Fair, H; Fairhurst, S; Fan, X; Fang, Q; Farinon, S; Farr, B; Farr, W M; Favata, M; Fays, M; Fehrmann, H; Fejer, M M; Ferrante, I; Ferreira, E C; Ferrini, F; Fidecaro, F; Fiori, I; Fiorucci, D; Fisher, R P; Flaminio, R; Fletcher, M; Fong, H; Fournier, J -D; Franco, S; Frasca, S; Frasconi, F; Frei, Z; Freise, A; Frey, R; Frey, V; Fricke, T T; Fritschel, P; Frolov, V V; Fulda, P; Fyffe, M; Gabbard, H A G; Gair, J R; Gammaitoni, L; Gaonkar, S G; Garufi, F; Gatto, A; Gaur, G; Gehrels, N; Gemme, G; Gendre, B; Genin, E; Gennai, A; George, J; Gergely, L; Germain, V; Ghosh, Archisman; Ghosh, S; Giaime, J A; Giardina, K D; Giazotto, A; Gill, K; Glaefke, A; Goetz, E; Goetz, R; Gondan, L; Gonz'alez, G; Castro, J M Gonzalez; Gopakumar, A; Gordon, N A; Gorodetsky, M L; Gossan, S E; Gosselin, M; Gouaty, R; Graef, C; Graff, P B; Granata, M; Grant, A; Gras, S; Gray, C; Greco, G; Green, A C; Groot, P; Grote, H; Grunewald, S; Guidi, G M; Guo, X; Gupta, A; Gupta, M K; Gushwa, K E; Gustafson, E K; Gustafson, R; Hacker, J J; Hall, B R; Hall, E D; Hammond, G; Haney, M; Hanke, M M; Hanks, J; Hanna, C; Hannam, M D; Hanson, J; Hardwick, T; Harms, J; Harry, G M; Harry, I W; Hart, M J; Hartman, M T; Haster, C -J; Haughian, K; Heidmann, A; Heintze, M C; Heitmann, H; Hello, P; Hemming, G; Hendry, M; Heng, I S; Hennig, J; Heptonstall, A W; Heurs, M; Hild, S; Hoak, D; Hodge, K A; Hofman, D; Hollitt, S E; Holt, K; Holz, D E; Hopkins, P; Hosken, D J; Hough, J; Houston, E A; Howell, E J; Hu, Y M; Huang, S; Huerta, E A; Huet, D; Hughey, B; Husa, S; Huttner, S H; Huynh-Dinh, T; Idrisy, A; Indik, N; Ingram, D R; Inta, R; Isa, H N; Isac, J -M; Isi, M; Islas, G; Isogai, T; Iyer, B R; Izumi, K; Jacqmin, T; Jang, H; Jani, K; Jaranowski, P; Jawahar, S; Jim'enez-Forteza, F; Johnson, W W; Jones, D I; Jones, R; Jonker, R J G; Ju, L; K, Haris; Kalaghatgi, C V; Kalogera, V; Kandhasamy, S; Kang, G; Kanner, J B; Karki, S; Kasprzack, M; Katsavounidis, E; Katzman, W; Kaufer, S; Kaur, T; Kawabe, K; Kawazoe, F; K'ef'elian, F; Kehl, M S; Keitel, D; Kelley, D B; Kells, W; Kennedy, R; Key, J S; Khalaidovski, A; Khalili, F Y; Khan, I; Khan, S; Khan, Z; Khazanov, E A; Kijbunchoo, N; Kim, C; Kim, J; Kim, K; Kim, Nam-Gyu; Kim, Namjun; Kim, Y -M; King, E J; King, P J; Kinzel, D L; Kissel, J S; Kleybolte, L; Klimenko, S; Koehlenbeck, S M; Kokeyama, K; Koley, S; Kondrashov, V; Kontos, A; Korobko, M; Korth, W Z; Kowalska, I; Kozak, D B; Kringel, V; Krishnan, B; Kr'olak, A; Krueger, C; Kuehn, G; Kumar, P; Kuo, L; Kutynia, A; Lackey, B D; Landry, M; Lange, J; Lantz, B; Lasky, P D; Lazzarini, A; Lazzaro, C; Leaci, P; Leavey, S; Lebigot, E O; Lee, C H; Lee, H K; Lee, H M; Lee, K; Lenon, A; Leonardi, M; Leong, J R; Leroy, N; Letendre, N; Levin, Y; Levine, B M; Li, T G F; Libson, A; Littenberg, T B; Lockerbie, N A; Logue, J; Lombardi, A L; Lord, J E; Lorenzini, M; Loriette, V; Lormand, M; Losurdo, G; Lough, J D; L"uck, H; Lundgren, A P; Luo, J; Lynch, R; Ma, Y; MacDonald, T; Machenschalk, B; MacInnis, M; Macleod, D M; Maga~na-Sandoval, F; Magee, R M; Mageswaran, M; Majorana, E; Maksimovic, I; Malvezzi, V; Man, N; Mandel, I; Mandic, V; Mangano, V; Mansell, G L; Manske, M; Mantovani, M; Marchesoni, F; Marion, F; M'arka, S; M'arka, Z; Markosyan, A S; Maros, E; Martelli, F; Martellini, L; Martin, I W; Martin, R M; Martynov, D V; Marx, J N; Mason, K; Masserot, A; Massinger, T J; Masso-Reid, M; Matichard, F; Matone, L; Mavalvala, N; Mazumder, N; Mazzolo, G; McCarthy, R; McClelland, D E; McCormick, S; McGuire, S C; McIntyre, G; McIver, J; McManus, D J; McWilliams, S T; Meacher, D; Meadors, G D; Meidam, J; Melatos, A; Mendell, G; Mendoza-Gandara, D; Mercer, R A; Merilh, E; Merzougui, M; Meshkov, S; Messenger, C; Messick, C; Meyers, P M; Mezzani, F; Miao, H; Michel, C; Middleton, H; Mikhailov, E E; Milano, L; Miller, J; Millhouse, M; Minenkov, Y; Ming, J; Mirshekari, S; Mishra, C; Mitra, S; Mitrofanov, V P; Mitselmakher, G; Mittleman, R; Moggi, A; Mohan, M; Mohapatra, S R P; Montani, M; Moore, B C; Moore, C J; Moraru, D; Moreno, G; Morriss, S R; Mossavi, K; Mours, B; Mow-Lowry, C M; Mueller, C L; Mueller, G; Muir, A W; Mukherjee, Arunava; Mukherjee, D; Mukherjee, S; Mukund, N; Mullavey, A; Munch, J; Murphy, D J; Murray, P G; Mytidis, A; Nardecchia, I; Naticchioni, L; Nayak, R K; Necula, V; Nedkova, K; Nelemans, G; Neri, M; Neunzert, A; Newton, G; Nguyen, T T; Nielsen, A B; Nissanke, S; Nitz, A; Nocera, F; Nolting, D; Normandin, M E; Nuttall, L K; Oberling, J; Ochsner, E; O'Dell, J; Oelker, E; Ogin, G H; Oh, J J; Oh, S H; Ohme, F; Oliver, M; Oppermann, P; Oram, Richard J; O'Reilly, B; O'Shaughnessy, R; Ottaway, D J; Ottens, R S; Overmier, H; Owen, B J; Pai, A; Pai, S A; Palamos, J R; Palashov, O; Palomba, C; Pal-Singh, A; Pan, H; Pankow, C; Pannarale, F; Pant, B C; Paoletti, F; Paoli, A; Papa, M A; Paris, H R; Parker, W; Pascucci, D; Pasqualetti, A; Passaquieti, R; Passuello, D; Patricelli, B; Patrick, Z; Pearlstone, B L; Pedraza, M; Pedurand, R; Pekowsky, L; Pele, A; Penn, S; Perreca, A; Phelps, M; Piccinni, O; Pichot, M; Piergiovanni, F; Pierro, V; Pillant, G; Pinard, L; Pinto, I M; Pitkin, M; Poggiani, R; Popolizio, P; Porter, E; Post, A; Powell, J; Prasad, J; Predoi, V; Premachandra, S S; Prestegard, T; Price, L R; Prijatelj, M; Principe, M; Privitera, S; Prodi, G A; Prokhorov, L; Puncken, O; Punturo, M; Puppo, P; P"urrer, M; Qi, H; Qin, J; Quetschke, V; Quintero, E A; Quitzow-James, R; Raab, F J; Rabeling, D S; Radkins, H; Raffai, P; Raja, S; Rakhmanov, M; Rapagnani, P; Raymond, V; Razzano, M; Re, V; Read, J; Reed, C M; Regimbau, T; Rei, L; Reid, S; Reitze, D H; Rew, H; Reyes, S D; Ricci, F; Riles, K; Robertson, N A; Robie, R; Robinet, F; Rocchi, A; Rolland, L; Rollins, J G; Roma, V J; Romano, R; Romanov, G; Romie, J H; Rosi'nska, D; Rowan, S; R"udiger, A; Ruggi, P; Ryan, K; Sachdev, S; Sadecki, T; Sadeghian, L; Salconi, L; Saleem, M; Salemi, F; Samajdar, A; Sammut, L; Sampson, L; Sanchez, E J; Sandberg, V; Sandeen, B; Sanders, J R; Sassolas, B; Sathyaprakash, B S; Saulson, P R; Sauter, O; Savage, R L; Sawadsky, A; Schale, P; Schilling, R; Schmidt, J; Schmidt, P; Schnabel, R; Schofield, R M S; Sch"onbeck, A; Schreiber, E; Schuette, D; Schutz, B F; Scott, J; Scott, S M; Sellers, D; Sengupta, A S; Sentenac, D; Sequino, V; Sergeev, A; Serna, G; Setyawati, Y; Sevigny, A; Shaddock, D A; Shah, S; Shahriar, M S; Shaltev, M; Shao, Z; Shapiro, B; Shawhan, P; Sheperd, A; Shoemaker, D H; Shoemaker, D M; Siellez, K; Siemens, X; Sigg, D; Silva, A D; Simakov, D; Singer, A; Singer, L P; Singh, A; Singh, R; Singhal, A; Sintes, A M; Slagmolen, B J J; Smith, J R; Smith, N D; Smith, R J E; Son, E J; Sorazu, B; Sorrentino, F; Souradeep, T; Srivastava, A K; Staley, A; Steinke, M; Steinlechner, J; Steinlechner, S; Steinmeyer, D; Stephens, B C; Stevenson, S; Stone, R; Strain, K A; Straniero, N; Stratta, G; Strauss, N A; Strigin, S; Sturani, R; Stuver, A L; Summerscales, T Z; Sun, L; Sutton, P J; Swinkels, B L; Szczepa'nczyk, M J; Tacca, M; Talukder, D; Tanner, D B; T'apai, M; Tarabrin, S P; Taracchini, A; Taylor, R; Theeg, T; Thirugnanasambandam, M P; Thomas, E G; Thomas, M; Thomas, P; Thorne, K A; Thorne, K S; Thrane, E; Tiwari, S; Tiwari, V; Tokmakov, K V; Tomlinson, C; Tonelli, M; Torres, C V; Torrie, C I; T"oyr"a, D; Travasso, F; Traylor, G; Trifir`o, D; Tringali, M C; Trozzo, L; Tse, M; Turconi, M; Tuyenbayev, D; Ugolini, D; Unnikrishnan, C S; Urban, A L; Usman, S A; Vahlbruch, H; Vajente, G; Valdes, G; Vallisneri, M; van Bakel, N; van Beuzekom, M; Brand, J F J van den; Broeck, C Van Den; Vander-Hyde, D C; van der Schaaf, L; van Heijningen, J V; van Veggel, A A; Vardaro, M; Vass, S; Vas'uth, M; Vaulin, R; Vecchio, A; Vedovato, G; Veitch, J; Veitch, P J; Venkateswara, K; Verkindt, D; Vetrano, F; Vicer'e, A; Vinciguerra, S; Vine, D J; Vinet, J -Y; Vitale, S; Vo, T; Vocca, H; Vorvick, C; Voss, D; Vousden, W D; Vyatchanin, S P; Wade, A R; Wade, L E; Wade, M; Walker, M; Wallace, L; Walsh, S; Wang, G; Wang, H; Wang, M; Wang, X; Wang, Y; Ward, R L; Warner, J; Was, M; Weaver, B; Wei, L -W; Weinert, M; Weinstein, A J; Weiss, R; Welborn, T; Wen, L; Wessels, P; Westphal, T; Wette, K; Whelan, J T; White, D J; Whiting, B F; Williams, R D; Williamson, A R; Willis, J L; Willke, B; Wimmer, M H; Winkler, W; Wipf, C C; Wittel, H; Woan, G; Worden, J; Wright, J L; Wu, G; Yablon, J; Yam, W; Yamamoto, H; Yancey, C C; Yap, M J; Yu, H; Yvert, M; zny, A Zadro; Zangrando, L; Zanolin, M; Zendri, J -P; Zevin, M; Zhang, F; Zhang, L; Zhang, M; Zhang, Y; Zhao, C; Zhou, M; Zhou, Z; Zhu, X J; Zucker, M E; Zuraw, S E; Zweizig, J

    2016-01-01

    Supplemental information for a Letter reporting the rate of binary black hole (BBH) coalescences inferred from 16 days of coincident Advanced LIGO observations surrounding the transient gravitational wave signal GW150914. In that work we reported various rate estimates whose 90\\% credible intervals fell in the range $2$--$600 \\, \\mathrm{Gpc}^{-3} \\mathrm{yr}^{-1}$. Here we give details of our method and computations, including information about our search pipelines, a derivation of our likelihood function for the analysis, a description of the astrophysical search trigger distribution expected from merging BBHs, details on our computational methods, a description of the effects and our model for calibration uncertainty, and an analytic method of estimating our detector sensitivity that is calibrated to our measurements.

  1. Test studies of gas flow in rock and coal surrounding a mined coal seam

    Institute of Scientific and Technical Information of China (English)

    Lv Youchang

    2012-01-01

    An analysis of the variation rule of abutment pressure at the mining working face in a single coal seam and the mechanical behavior of surrounding rock during stoping is presented.Consideration of the elastic and plastic deformation zones that develop during the mining process allowed the determination of a relationship between horizontal stress and vertical stress.Based on this,a confined pressure unloading test was conducted by the use of the "gas-containing coal thermo-fluid-solid coupling 3-axis servo seepage" experimental apparatus.Thus,gas flow patterns in the elastic and plastic zones were derived from an experimental point of view.Darcy's law and the Klinkenberg effect were used to derive a gas flow equation for the elastic and plastic stress fields.The study of gas flow phenomena at the working face during coal mining is of great importance for the study of gas migration and enrichment oatterns.

  2. Detained and Dying: Ethical Issues Surrounding End-of-Life Care in Prison.

    Science.gov (United States)

    Stensland, Meredith; Sanders, Sara

    2016-01-01

    Prisons are increasingly being called upon to provide end-of-life (EOL) care within the restrictive correctional environment. Several relatively recent phenomena have brought medical ethics to the forefront of prison EOL care-including aging behind bars, a paradigm shift in prison culture, the increasing rate of in-prison deaths, and the corresponding prison hospice movement. This article examines prominent ethical issues that emerge for prison personnel who are tasked with providing care to terminally ill offenders by presenting three offender composite characters that exemplify dying offenders and emergent ethical issues surrounding their care. Identification and critical analysis of these ethical issues demonstrate the need for strong commitment to ethical practice and highlights specific issues for prisons to examine in their own EOL care practice.

  3. Extended stellar substructure surrounding the Bo\\"otes I dwarf spheroidal galaxy

    CERN Document Server

    Roderick, T A; Jerjen, H; Da Costa, G S

    2016-01-01

    We present deep stellar photometry of the Bo\\"otes I dwarf spheroidal galaxy in g and i band filters, taken with the Dark Energy Camera at Cerro Tololo in Chile. Our analysis reveals a large, extended region of stellar substructure surrounding the dwarf, as well as a distinct over-density encroaching on its tidal radius. A radial profile of the Bo\\"otes I stellar distribution shows a break radius indicating the presence of extra-tidal stars. These observations strongly suggest that Bo\\"otes I is experiencing tidal disruption, although not as extreme as that exhibited by the Hercules dwarf spheroidal. Combined with revised velocity dispersion measurements from the literature, we see evidence suggesting the need to review previous theoretical models of the Bo\\"otes I dwarf spheroidal galaxy.

  4. Detained and Dying: Ethical Issues Surrounding End-of-Life Care in Prison.

    Science.gov (United States)

    Stensland, Meredith; Sanders, Sara

    2016-01-01

    Prisons are increasingly being called upon to provide end-of-life (EOL) care within the restrictive correctional environment. Several relatively recent phenomena have brought medical ethics to the forefront of prison EOL care-including aging behind bars, a paradigm shift in prison culture, the increasing rate of in-prison deaths, and the corresponding prison hospice movement. This article examines prominent ethical issues that emerge for prison personnel who are tasked with providing care to terminally ill offenders by presenting three offender composite characters that exemplify dying offenders and emergent ethical issues surrounding their care. Identification and critical analysis of these ethical issues demonstrate the need for strong commitment to ethical practice and highlights specific issues for prisons to examine in their own EOL care practice. PMID:27462955

  5. Effect of size and surrounding forest vegetation on chemical properties of soil in forest gaps

    OpenAIRE

    Özcan M; Gökbulak F

    2015-01-01

    Forest gaps have different microclimatic conditions as compared to the surrounding areas, depending on gap size and surrounding forest types and affec­ting the biological, chemical, physical, and hydrological processes in the forest openings. The objective of this study was to determine the effect of forest gap size and surrounding forest cover type (beech or mixed stands) on the soil of forest opening by analyzing several soil chemical soil properties (pH, electrical conductivity - EC, organ...

  6. Structural deformation of metallic uranium surrounding hydride growth sites

    International Nuclear Information System (INIS)

    Highlights: • UH3 formation on uranium surfaces by a controlled uptake of hydrogen at 240 °C. • Large hydride growths (35–125 μm in diameter) form at the surface. • Confined hydride expansion during growth generates stress in the subsurface. • EBSD scans found micro-cracking and twins as forms of stress relief in the metal. - Abstract: Electron backscatter diffraction (EBSD) was utilised to probe the microstructure of uranium metal in the vicinity of surface corrosion pits, resulting from hydrogen exposure (5 × 104 Pa, at 240 °C). Microstructural analysis of the surface revealed a subtle increase of grain orientation variation for grains at the border of the hydride growths. Cross sectional analysis, at pit sites, revealed significant microstructure deformation in the form of crystal twinning and micro-cracking beneath the surface. These observations provide qualitative evidence that local stress intensities generated as a consequence of hydride growth and confinement, were sufficient to cause deformation within the parent metal

  7. ITI种植系统用于后牙游离端缺失修复中的疗效评价%Clinical evaluation of ITI system for implant-supported restoration in the treatment of posterior free-end edentulism

    Institute of Scientific and Technical Information of China (English)

    王晓洁; 郭莉; 孟慧萍; 陈宇梅

    2011-01-01

    目的 评价IPI种植体用于后牙游离端缺失修复中的临床疗效.方法 后牙游离端缺失采用种植义齿修复的56例共227个种植体.其中即刻种植4例,上颌窦内提升术9例.3~6个月后行上部结构修复.定期随访种植牙的探诊深度、种植体骨结合状况、种植体的骨丧失水平.结果 经过1~4年的随访观察,227颗种植体无一松动脱落,均未发生神经损伤和感觉异常.种植体稳定,未见其周围有X线透视区.种植体周围组织健康,种植体龈沟探诊深度为(2.93 ± 0.37)mm;术后1年的骨丧失水平均值为(0.92 ±0.62)mm,l年后的平均每年骨吸收均<0.2 mm.病人对舒适度、美观性和咀嚼效率评价良好.结论 采用ITI种植系统对后牙游离端缺失进行修复,操作简单,临床效果好.%Objective To evaluate the clinical effect and advantages of implant-supported restoration in the treatment of posterior free-end edentulism. Methods A total of 227 ITI dental implants were implanted according to standard procedure of ITI implantation operation in 56 cases of posterior free-end edentulism. There were 4 eases of immediate implant and 9 cases of maxillary sinus augmentation. Abutments were connected for restoration after 3 - 6 months. Probing depth, osseointegration of implants and bone loss level were regular followed-up. Results There was no ache and nerve injury in the sites of implantation and all dental implants were stable during the observation period of 1 - 4 years in 227 ITI dental implants. X-ray examination showed that the probing depth was (2.93 ± 0.62 ) mm and marginal bone surrotmding the neck of implant absorbed in (0. 92 ± 0.62) mm in first year and lower 0.2mm bone resorption in next one year after operation. Patients were satisfied with the final restoration effect on the whole. Conclusion The ITI Implant System offers you the advantages of a reliable、stable、simple and flexible prosthetic solution for the posterior free

  8. The effect of correlative risk factors on esthetic outcome of soft tissue for implant-supported single tooth restoration in anterior maxilla%上颌前牙区单牙种植软组织美学的相关因素分析

    Institute of Scientific and Technical Information of China (English)

    王凤; 张志勇; 赖红昌; 黄伟; 吴轶群

    2009-01-01

    PURPOSE: To evaluate the soft tissue around single-tooth implant in anterior maxilla with a newly developed pink esthetic score (PES) at the time of crown placement and 6-month follow-up, and to analyze the correlative factors affecting the assessment of PES. METHODS: 31 patients subjective to single-tooth replacement with ITI implant-supported restoration in anterior maxilla were included. Assessments of soft tissue after crown placement and 6-month follow-up were made. At the same time, age of the patients, abutment type, gingival biotype were recorded and the height of keratinized mucosa , the distance between alveolar crest and implant shoulder, periodontal index were measured. The correlations between PES and the factors were analyzed by Spearman rank correlation. RESULTS: PES for single-tooth implant was 6.90±2.52 at the time of crown placement and 9.55±2.15 after 6-month follow-up. PES had a higher score correlated with thick gingival biotype, solid abutment, wider keratinized mucosa, less distance between alveolar crest and implant shoulder and had no relation to the age of patients and periodontal index. CONCLUSIONS: Esthetic outcome of soft tissue for single tooth implant restoration is affected by many factors according to PES assessment. "Supported by Research Fund of Excellent Young Teachers of Shanghai Municipality(Grant No.jdy-07066).%目的:通过PES(pink esthetic score)评分指数对上颌前牙区单牙种植修复后软组织的美学效果进行评价,分析多组因素与PES得分的相关性.方法:随机选择31例上颌前牙区单牙缺失患者,共植入31枚ITI种植体,于修复完成当天及随访6个月后,使用PES指数对种植修复体周围软组织进行评分.记录患者年龄、牙周组织类型、基台类型,测量种植区角化龈宽度、邻面牙槽嵴顶至肩台的距离、牙周指数,使用Spearman等级相关分析各个因素与基线期、随访期PES总分的相关性.结果:修复完成当天PES值为6.90

  9. Locator附着体种植覆盖义齿在肿瘤切除术后牙列缺失修复中的应用%Application of Implant-supported Overdenture with Locator Attachments in Patients with Maxillofacial Tumor after Curative Resection

    Institute of Scientific and Technical Information of China (English)

    吴东; 肖妍君; 李桐军; 郑静宜; 黄文秀

    2014-01-01

    Objective: To discuss the application of implant-supported overdenture with Locator attachments used in patients with maxillofacial tumor after curative resection. Methods: 6 patients with maxillofacial tumor after curative resection were submitted to implant therapy. After a period of 3 to 4 months, overdentures using Locator system were initiated. Questionnaire on the satisfaction rate and periodic examination was applied to these patients. Results: In the follow-up period from 1 to 5 years, no implant was failed and bone resorption was not obvious. The overdenture with Locator attachments were improving in retention and reliability. And the patients were much more statisfied with the stability, comfortablity and mastication of the overdentures. Conclusion: The implant overdenture using Locator system may be useful to solve the problem of retention and stability of complete denture , in maxillofacial tumor resection patients.%目的:口腔颌面部肿瘤切除手术及其他治疗对颌骨造成的创伤可能会对口腔重建修复和功能恢复造成一定的困难。本文旨在介绍口腔颌面部肿瘤术后患者采用Locator附着体支持式种植覆盖义齿修复牙列缺失的应用方法,探讨解决无牙颌导致义齿固位不良的修复新方法。方法:对6例颌面部肿瘤切除术后牙列缺失患者,在颌骨内植入种植体,3~4个月后进行Locator附着体支持的种植覆盖义齿修复,并对其进行定期复查及种植覆盖总义齿满意度情况调查。结果:种植术后,通过1~5年的临床观察,所有种植体均无松动、脱落,Locator附着体支持式种植覆盖义齿固位良好。种植体植入后及负载后X线片对比,显示种植体-骨结合良好,种植体颈部无明显骨吸收。患者戴用Locator基台种植覆盖义齿,义齿的稳定性有明显改善,咀嚼效率提高,使用效果满意。结论:对口腔颌面部肿瘤切除术后的患者,Locator附着体

  10. Clinical study of crown shape control effect of horizontal food impaction in implant supported fixed denture in elderly patients%牙冠形态对老年种植修复患者水平型食物嵌塞防治效果的临床研究

    Institute of Scientific and Technical Information of China (English)

    崔广; 刘宇; 郑洁; 宫琳

    2014-01-01

    目的:观察不同邻面形态的种植单冠修复后对老年种植患者后牙水平型食物嵌塞的防治效果。方法:将80例老年患者第一磨牙种植冠按修复间隙的大小分成两组(A组距离<10.0mm, B组≥10.0mm),组内再随机分为对照组和试验组各20例,分别按照不同邻面形态制作硬质树脂临时冠并戴入,两两对比并进行随访观察。所有病例在观察6个月后拆除硬质树脂临时冠,使用全解剖形态氧化锆种植冠完成最终修复。结果:不同大小的修复间隙,对照组食物嵌塞情况均严重于试验组,两者存在显著性差异(P<0.05)。结论:针对不同大小的修复间隙,特殊的种植冠邻面形态短期内有利于防治老年患者后牙水平型食物嵌塞,长期的临床效果需进一步研究证实。%Objective:Food impaction is one of the main complications of fixed partial denture restoration, and implant supported fixed partial denture is no exception, especially horizontal food impaction. The current study aim to examine the treatment effects of food impaction by adjusting the interproximal contour of the implant crowns.Method:80 cases of posterior teeth restored with implant crowns were randomly divided into group A(<10.0mm), and group B(≥10.0mm), according to the edentulous space. Each group was then subdivided into two groups, each with 20 cases, that were restored with temporary resin crown of different interproximal contour, replaced by zirconia-ceramic crowns 6 month later. Proximal contact, the occurrence of horizontal food impaction and clinical parameters were recorded at each time point. All results were futher compared and analyzed statistically.Results:In group A, the food impaction rate of the control group and experimental group was 80% and 25%, respectively. In group B, the food impaction rate of the control group and experimental group was 100% and 15%, respectively. The food impaction rates of both experiment

  11. The cross-correlation of signals and spatial impression in surround sound reproduction

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The relationship between the cross-correlation coefficients of feeding signals and auditory spatial impression(ASI) which are created by the left,right,left surround and right surround loudspeakers in 5.1 channel surround sound system is investigated by psychoacoustic experiments.The results show that for reproducing by the front left-right or left-right surround loudspeakers pair,the auditory source width(ASW) can be broadened by controlling the crosscorrelation coefficients of feeding signals to some e...

  12. Metal accumulation in wild plants surrounding mining wastes

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, R. Carrillo [Soil Chemistry, IRENAT, Colegio de Postgraduados, Carr, Mexico-Texcoco km 36.5, Montecillo, Mexico 56230 (Mexico)]. E-mail: crogelio@colpos.mx; Gonzalez-Chavez, M.C.A. [Soil Microbiology, IRENAT, Colegio de Postgraduados, Carr, Mexico-Texcoco km 36.5, Montecillo, Mexico 56230 (Mexico)]. E-mail: carmeng@colpos.mx

    2006-11-15

    Four sites were selected for collection of plants growing on polluted soil developed on tailings from Ag, Au, and Zn mines at the Zacatecas state in Mexico. Trace element concentrations varied between sites, the most polluted area was at El Bote mine near to Zacatecas city. The ranges of total concentration in soil were as follows: Cd 11-47, Ni 19-26, Pb 232-695, Mn 1132-2400, Cu 134-186 and Zn 116-827 mg kg{sup -1} air-dried soil weight. All soil samples had concentrations above typical values for non-polluted soils from the same soil types (Cd 0.6 {+-} 0.3, Ni 52 {+-} 4, Pb 41 {+-} 3 mg kg{sup -1}). However, for the majority of samples the DTPA-extractable element concentrations were less than 10% of the total. Some of the wild plants are potentially metal tolerant, because they were able to grow in highly polluted substrates. Plant metal analysis revealed that most species did not translocate metals to their aerial parts, therefore they behave as excluder plants. Polygonum aviculare accumulated Zn (9236 mg kg{sup -1}) at concentrations near to the criteria for hyperaccumulator plants. Jatropha dioica also accumulated high Zn (6249 mg kg{sup -1}) concentrations. - Polygonum aviculare and Jatropha dioica accumulated Zn at concentrations near to the criteria for hyperaccumulator plants.

  13. Failure mechanism of bolting support and high-strength bolt-grouting technology for deep and soft surrounding rock with high stress

    Institute of Scientific and Technical Information of China (English)

    李术才; 王洪涛; 王琦; 江贝; 王富奇; 郭念波; 刘文江; 任尧喜

    2016-01-01

    In deep underground mining, the surrounding rocks are very soft with high stress. Their deformation and destruction are serious, and frequent failures occur on the bolt support. The failure mechanism of bolt support is proposed to solve these problems. A calculation theory is established on the bond strength of the interface between the anchoring agent and surrounding rocks. An analysis is made on the influence law of different mechanical parameters of surrounding rocks on the interfacial bond strength. Based on the research, a new high-strength bolt-grouting technology is developed and applied on site. Besides, some helpful engineering suggestions and measures are proposed. The research shows that the serious deformation and failure, and the lower bond strength are the major factors causing frequent failures of bolt support. So, the bolt could not give full play to its supporting potential. It is also shown that as the integrity, strength, interface dilatancy and stress of surrounding rocks are improved, the bond strength will increase. So, the anchoring force on surrounding rocks can be effectively improved by employing an anchoring agent with high sand content, mechanical anchoring means, or grouting reinforcement. The new technology has advantages in a high strength, imposing pre-tightening force, and giving full play to the bolt supporting potential. Hence, it can improve the control effect on surrounding rocks. All these could be helpful references for the design of bolt support in deep underground mines.

  14. Misconceptions Surrounding Climate Change: A Review of the Literature

    Science.gov (United States)

    Templeton, C. M.; McNeal, K. S.; Libarkin, J.

    2011-12-01

    communicate and share resources in a common community. Many organizations are addressing these critical needs and we will compile these efforts in our analysis as well.

  15. Electromembrane surrounded solid phase microextraction using electrochemically synthesized nanostructured polypyrrole fiber.

    Science.gov (United States)

    Mohammadkhani, Elham; Yamini, Yadollah; Rezazadeh, Maryam; Seidi, Shahram

    2016-04-22

    Electromembrane surrounded solid phase microextraction using conductive polymers as the sorbent is carried out for the first time for extraction of two antidepressants including amitriptyline (AMI) and doxepin (DOX), as model analytes. The polypyrrole coating was prepared and utilized as both cathode and SPME sorbent. Different variables such as the conditions for preparation of polypyrrole fiber, pH of the donor and the acceptor phases, applied voltage, and extraction time were optimized. Under the optimized conditions, figures of merit of the proposed method were investigated in human whole blood and urine samples. Intra- and inter-assay precisions ranged between 3.1-7.5% and 7.6-12.3%, respectively were obtained in different extraction media. Detection limits of 0.15 and 0.05 for AMI and 0.3 and 0.1ngmL(-1) for DOX were achieved in the urine and blood samples, respectively. Linearity of the method was studied up to 50.0ngmL(-1) for both analytes and coefficients of determination better than 0.9966 were achieved. Regardless of the high sample cleanup, which makes the proposed method suitable for analysis of drugs from complicated matrices, clean chromatograms were obtained. Finally, the proposed method was applied for analysis of AMI and DOX in different real samples and reasonable data were obtained. PMID:27033980

  16. Ultrastructural characterization of soft tissues surrounding implanted hip prosthesis by complementary PIXE and TEM methods

    Energy Technology Data Exchange (ETDEWEB)

    Jallot, E. E-mail: edouard.jallot@uni-reims.fr; Benhayoune, H.; Kilian, L.; Balossier, G.; Bonhomme, P.; Oudadesse, H.; Irigaray, J.L

    1999-08-01

    We study soft tissues surrounding hip prostheses from three different patients. We evaluate the elemental composition of different fragments. The tissues are examined by means of two complementary methods in such analysis: Particle Induced X-ray Emission (PIXE) and Scanning Transmission Electron Microscopy (STEM) coupled with X-ray microanalysis (Energy Dispersive X-ray, EDX). These methods allow to determine locally at 'macro' and 'micro' level the chemistry of soft tissues. The findings confirmed the presence of metal in soft tissue near the three different hips. The tissues' composition undergoes important modifications with a systematic elevation of trace metal in patients with failed implants. We observe a corrosion which causes the continual release of particles into the tissues. Corrosion alters the shape size and chemical composition of wear particles embedded in soft tissue around the failed hip. EDX analysis showed that the wear particles contained varying quantities of titanium and aluminium. This phenomenon may be related with the variation of time of contact with soft tissues for each particle and Ti solubility.

  17. Ultrastructural characterization of soft tissues surrounding implanted hip prosthesis by complementary PIXE and TEM methods

    Science.gov (United States)

    Jallot, E.; Benhayoune, H.; Kilian, L.; Balossier, G.; Bonhomme, P.; Oudadesse, H.; Irigaray, J. L.

    We study soft tissues surrounding hip prostheses from three different patients. We evaluate the elemental composition of different fragments. The tissues are examined by means of two complementary methods in such analysis: Particle Induced X-ray Emission (PIXE) and Scanning Transmission Electron Microscopy (STEM) coupled with X-ray microanalysis (Energy Dispersive X-ray, EDX). These methods allow to determine locally at `macro' and `micro' level the chemistry of soft tissues. The findings confirmed the presence of metal in soft tissue near the three different hips. The tissues' composition undergoes important modifications with a systematic elevation of trace metal in patients with failed implants. We observe a corrosion which causes the continual release of particles into the tissues. Corrosion alters the shape size and chemical composition of wear particles embedded in soft tissue around the failed hip. EDX analysis showed that the wear particles contained varying quantities of titanium and aluminium. This phenomenon may be related with the variation of time of contact with soft tissues for each particle and Ti solubility.

  18. Influence of underground water seepage flow on surrounding rock deformation of multi-arch tunnel

    Institute of Scientific and Technical Information of China (English)

    LI Xi-bing; ZHANG Wei; LI Di-yuan; WANG Qi-sheng

    2008-01-01

    Based on a typical multi-arch tunnel in a freeway, the fast Lagrangian analysis of continua in 3 dimensions(FLAC3D) was used to calculate the surrounding rock deformation of the tunnel under which the effect of underground water seepage flow was taken into account or not. The distribution of displacement field around the multi-arch tunnel, which is influenced by the seepage field, was gained. The result indicates that the settlement values of the vault derived from coupling analysis are bigger when considering the seepage flow effect than that not considering. Through the contrast of arch subsidence quantities calculated by two kinds of computation situations, and the comparison between the calculated and measured value of tunnel vault settlement, it is found that the calculated value(5.7-6.0 mm) derived from considering the seepage effect is more close to the measured value(5.8-6.8 mm).Therefore, it is quite necessary to consider the seepage flow effect of the underground water in aquiferous stratum for multi-arch tunnel design.

  19. Properties of Schist Extracted in the City of Denizli Surroundings as Construction Material

    Directory of Open Access Journals (Sweden)

    Saffet Yağız

    2011-03-01

    Full Text Available There are various type of building stone extracted at stone quarries in the city of Denizli surroundings. Travertine, limestone and schist quarries are the most common in the area. Schist that is one of the units of Menderes massive is the main natural stone sources in Çal, Bekilli and Baklan Triangle in the northeast of the City. The aim of this study is to investigate the usability of schist stone as building stone quarried in the area. To obtain the aim, geological investigations were conducted in the field and representative samples were collected from the quarries. On the samples, petrograpical, mineralogical (XRD, chemical (XRF analysis and geomechanical test (i.e., uniaxial compressive strength, Schmidt hardness, water absorption by weight, effective porosity, fullness ratio, flexural strength, sonic wave velocity, modulus of elasticity, natural and saturated unit weight were conducted and the usability of schist stone as building stone have been studied by evaluating obtained findings. Analysis and relevant tests were conducted in accordance with international standards and procedures. Concluding remark is that quarried schist stone in the area are acceptably good as building stone to be used for both interior and exterior of construction building and outdoors as coverage material.

  20. Different surrounding landscapes may result in different fish assemblages in East African seagrass beds

    NARCIS (Netherlands)

    Dorenbosch, M.; Grol, M.G.G.; Nagelkerken, I.; Velde, G. van der

    2006-01-01

    Few studies have considered how seagrass fish assemblages are influenced by surrounding habitats. This information is needed for a better understanding of the connectivity between tropical coastal ecosystems. To study the effects of surrounding habitats on the composition, diversity and densities of

  1. Effects of surrounding elements on city image in the sample of Erzurum city

    Directory of Open Access Journals (Sweden)

    S. Ozer

    2010-05-01

    Full Text Available Structural elements which are the parts of city identities are shaped as the result of social and cultural characteristics and natural factors. In order to increase visual quality of cities and make cities more liveable landscape architects use not only living materials such as plants but also nonliving materials. This study was carried out to investigate the effects of surrounding elements which are vertical elements in landscape designs, on functional and city aesthetics. With this aim, materials used in surrounding elements around houses in Erzurum, houses surrounded by these elements and their harmony with their surroundings, aesthetics and functional effects were investigated and their contributions to city image were determined. While surrounding elements are mainly adequate in functions, they are lower quality in aesthetics. Some suggestions were offered for the city images that local councils should be careful on and due to Universiade in 2011.

  2. Varieties of Quest and the Religious Openness Hypothesis within Religious Fundamentalist and Biblical Foundationalist Ideological Surrounds

    Directory of Open Access Journals (Sweden)

    P. J. Watson

    2013-12-01

    Full Text Available According to the Religious Openness Hypothesis, the religious and psychological openness of American Christians is obscured by a defensive ghettoization of thought associated with a Religious Fundamentalist Ideological Surround and can be discovered instead within a Biblical Foundationalist Ideological Surround. A test of this claim examined Religious Fundamentalism, Biblical Foundationalism, Quest, and Multidimensional Quest Scales in 432 undergraduates. Christian Religious Reflection, Religious Schema, and Religious Orientation measures clarified these two ideological surrounds. Partial correlations controlling for Biblical Foundationalism described a Religious Fundamentalist Ideological Surround that more strongly rejected Quest and that more generally displayed a failure to integrate faith with intellect. Partial correlations controlling for Religious Fundamentalism revealed a Biblical Foundationalist Ideological Surround that was more open to Quest and that offered numerous demonstrations of an ability to unite faith with intellect. These data supplemented previous investigations in demonstrating that Christianity and other traditional religions have ideological resources for promoting a faithful intellect.

  3. Restoration strategies for radioactively contaminated sites and their close surroundings

    Energy Technology Data Exchange (ETDEWEB)

    Zeevaert, Th. [SCK-CEN, Boeretang, Mol (Belgium); Bousher, A.; Wragg, S. [Westlakes Scientific Consulting, Moor Row, Cumbria (United Kingdom); Brendler, V. [Forschungszentrum Rossendorf, Institut fuer Radiochemie, Dresden (Germany); Jensen, P.H. [Risoe National Laboratory, Dpt. of Nuclear Safety Research, Roskilde (Denmark); Nordlinder, S. [Studsvik Eco and Safety AB, Nykoeping (Sweden)

    2000-05-01

    This paper deals with the results of a project, set up in the fourth framework of the EC Nuclear Fission Safety Programme. The purpose of this project was to elaborate a methodology for ranking restoration options as a function of site- and contamination characteristics and to apply this methodology to example cases, typical for major classes of radioactively contaminated sites. The ranking methodology has been based on the radiation protection principles of justification and optimisation. The criteria that have been taken into account, include: - radiological health detriment; - economic costs; - social factors. These attributes have been further divided into sub-attributes forming a hierarchical structure and a MAU (multi-attribute utility) type of analysis has been set up for ranking restoration options with respect to these attributes. Five typical example sites have been studied; the Drigg low-level waste disposal site, the Ranstad uranic tailing site, the Molse Nete river, the Ravenglass estuary and the Tranebaerssjoen lake. Potentially relevant restoration techniques have been identified from four large categories, i.e. removal of sources, separation of contaminated fractions, containment and immobilization. Data with respect to their performance, osts and applicability were derived from an extensive literature review and collected in a MS-Access database. With respect to the radiological health attributes, the collective doses to the public and to the restoration workers have been assessed. The doses to the public have been assessed with and without the restoration measures implemented, in order to derive the dose savings associated with the restoration options. An important issue has been recognized to be physico-chemical phenomena, which may strongly influence the behaviour of the contaminants in the environment. Therefore a chemical speciation model has been integrated in the impact assessment model, which allowed the assessor to determine site

  4. Cholinergic enhancement reduces orientation-specific surround suppression but not visual crowding

    Directory of Open Access Journals (Sweden)

    Anna A. Kosovicheva

    2012-09-01

    Full Text Available Acetylcholine (ACh reduces the spatial spread of excitatory fMRI responses in early visual cortex and the receptive field sizes of V1 neurons. We investigated the perceptual consequences of these physiological effects of ACh with surround suppression and crowding, two tasks that involve spatial interactions between visual field locations. Surround suppression refers to the reduction in perceived stimulus contrast by a high-contrast surround stimulus. For grating stimuli, surround suppression is selective for the relative orientations of the center and surround, suggesting that it results from inhibitory interactions in early visual cortex. Crowding refers to impaired identification of a peripheral stimulus in the presence of flankers and is thought to result from excessive integration of visual features. We increased synaptic ACh levels by administering the cholinesterase inhibitor donepezil to healthy human subjects in a placebo-controlled, double-blind design. In Exp. 1, we measured surround suppression of a central grating using a contrast discrimination task with three conditions: 1 surround grating with the same orientation as the center (parallel, 2 surround orthogonal to the center, or 3 no surround. Contrast discrimination thresholds were higher in the parallel than in the orthogonal condition, demonstrating orientation-specific surround suppression (OSSS. Cholinergic enhancement reduced thresholds only in the parallel condition, thereby reducing OSSS. In Exp. 2, subjects performed a crowding task in which they reported the identity of a peripheral letter flanked by letters on either side. We measured the critical spacing between the target and flanking letters that allowed reliable identification. Cholinergic enhancement had no effect on critical spacing. Our findings suggest that ACh reduces spatial interactions in tasks involving segmentation of visual field locations but that these effects may be limited to early visual cortical

  5. Cholinergic enhancement reduces orientation-specific surround suppression but not visual crowding.

    Science.gov (United States)

    Kosovicheva, Anna A; Sheremata, Summer L; Rokem, Ariel; Landau, Ayelet N; Silver, Michael A

    2012-01-01

    Acetylcholine (ACh) reduces the spatial spread of excitatory fMRI responses in early visual cortex and receptive field size of V1 neurons. We investigated the perceptual consequences of these physiological effects of ACh with surround suppression and crowding, two phenomena that involve spatial interactions between visual field locations. Surround suppression refers to the reduction in perceived stimulus contrast by a high-contrast surround stimulus. For grating stimuli, surround suppression is selective for the relative orientations of the center and surround, suggesting that it results from inhibitory interactions in early visual cortex. Crowding refers to impaired identification of a peripheral stimulus in the presence of flankers and is thought to result from excessive integration of visual features. We increased synaptic ACh levels by administering the cholinesterase inhibitor donepezil to healthy human subjects in a placebo-controlled, double-blind design. In Experiment 1, we measured surround suppression of a central grating using a contrast discrimination task with three conditions: (1) surround grating with the same orientation as the center (parallel), (2) surround orthogonal to the center, or (3) no surround. Contrast discrimination thresholds were higher in the parallel than in the orthogonal condition, demonstrating orientation-specific surround suppression (OSSS). Cholinergic enhancement decreased thresholds only in the parallel condition, thereby reducing OSSS. In Experiment 2, subjects performed a crowding task in which they reported the identity of a peripheral letter flanked by letters on either side. We measured the critical spacing between the targets and flanking letters that allowed reliable identification. Cholinergic enhancement with donepezil had no effect on critical spacing. Our findings suggest that ACh reduces spatial interactions in tasks involving segmentation of visual field locations but that these effects may be limited to early

  6. [Characterization of dinosaur fossils and their surrounding rocks by atomic emission spectrometry and X-ray powder diffractometry].

    Science.gov (United States)

    Yang, Qun; Wang, Yi-lin; Li, Chao-zhen; Yuan, Bo

    2005-02-01

    More dinosaur fossils have been found in the Laochangqing valley, Lufeng county than anywhere else in the world, and the dinosaur fossils found here cover the longest time span (including the early and middle Jurassic ages). This excavation offers an ideal experimental base for prehistoric biology studies. This paper presents an elementary analysis of the components and structure of the dinosaur fossils in three different geologic-layers and their surrounding rocks in the above mentioned area. Atomic emission spectrum shows that the fossils are rich in the contents of calcium (>5%) and phosphor, but low in the content of silicon (3%-8%), while the surrounding rocks are high in the content of silicon (>10%). Furthermore, XRD results show that the major compound of the fossils is CaCO3 (66%), followed by SiO2 (17%); while that of the surrounding rocks is SiO2 (>80%), followed by CaCO3 (dinosaur fossils from other rocks. This paper provides valuable data for further zoological studies on the living conditions and evolution of the dinosaurs in the Laochangqing valley, Lufeng county.

  7. Information support of territorial wildlife management of Lake Baikal and the surrounding areas (Russia)

    Science.gov (United States)

    Lesnykh, Svetlana

    2013-04-01

    The UNESCO World Heritage Committee inscribed Lake Baikal in the World Heritage List under all four natural criteria as the most outstanding example of a freshwater ecosystem. It is the oldest and deepest lake in the world, which is the main freshwater reserve surrounded by a system of protected areas that have high scientific and natural values. However, there is a conflict between three main interests within the territory: the preservation of the unique ecosystem of the lake and its surrounding areas, the need for regional economic development, and protection of interests of the population, living on the shores of Lake Baikal. Solutions to the current challenges are seen in the development of control mechanisms for the wildlife management to ensure sustainable development and conservation of lake and the surrounding regions. For development mechanisms of territorial management of the complex and valuable area it is necessary to analyze features of its functioning and self-control (adaptable possibilities), allowing ecosystems to maintain their unique properties under influence of various external factors: anthropogenic (emissions, waste water, streams of tourists) and natural (climate change) load. While determining the direction and usage intensity of the territory these possibilities and their limits should be considered. Also for development of management strategy it is necessary to consider the relation of people to land and water, types of wildlife management, ownership, rent, protection from the negative effects, and etc. The relation of people to the natural area gives a chance to prioritize the direction in the resource use and their protection. Results of the scientific researches (reaction of an ecosystem on influence of various factors and system of relations to wildlife management objects) are the basis for the nature protection laws in the field of wildlife management and environmental protection. The methodology of legal zoning of the territory was

  8. Stress distributions in maxillary bone surrounding overdenture implants with different overdenture attachments.

    Science.gov (United States)

    Chun, H-J; Park, D-N; Han, C-H; Heo, S-J; Heo, M-S; Koak, J-Y

    2005-03-01

    In this study, effects of different overdenture attachments on the stress distributions in the maxillary bone surrounding the overdenture implants are studied. Four different types of attachment are considered. They are rigid Dalbo Stud, movable Dalbo Stress Broken, movable Dalro, and movable O-ring attachments. Three-dimensional finite element analysis was conducted with commercial package to obtain the stress distributions in the maxillary bone. Varying the attachment types and angle of inclination of load, the stress distributions in the portions of compact bone and trabecular bone were monitored separately. The analysis was conducted by assuming two different boundary conditions at the interface between cap and overdenture abutment in order to evaluate influence of interface boundary condition on stress distribution in the maxillary bone. They were perfect bonding condition and contact with friction at the interfaces. However, it is preferable to assume perfect bond condition at the interface for rigid type attachment systems and contact with friction at the interface for movable type attachment systems. From the numerical results, it was found that the load transfer mechanism of the implant system is altered significantly by the types of the overdenture attachment and also special care must be taken to assign proper boundary conditions at the interface for the analysis. The movable type Dalro attachment generated the highest maximum effective stress in the maxillary bone among the models under the same inclined loading condition for contact with friction. The rigid type Dalbo Stud attachment generated the smallest maximum effective stress in the maxillary bone among the models under the same inclined loading condition for perfect bonding condition. PMID:15707430

  9. Measurement of the optimum surround ratio inducing the highest perceived image contrast

    Science.gov (United States)

    Baek, Ye Seul; Kim, Youn Jin; Kim, Hong-Suk; Park, Seung-Ok

    2010-10-01

    Much research has shown that perceived image contrast increases as the surround luminance increases, but a number of recent studies reported opposite trends under higher surround luminance levels. We measured the change in perceived image contrast under a wide range of surround luminance levels covering from dark up to 2087 cd/m2. A large-area illuminator was used to illuminate the surround. It consists of 23 dimmable fluorescent lamps and a diffuser. Its maximum luminance is 2087 cd/m2 and could be adjusted to six lower levels. A set of paired comparison experiments was conducted to compare the perception of image contrast under seven different surround luminance levels. The results showed that the perceived image contrast varies with surround luminance and the maximum perceived image contrast is found near a surround ratio (SR) of 1. As SR increases from 0 to 1, the z score is increased, which can be fully expected by the Bartleson and Breneman effect. However, it is drastically decreased in the region of SR > 1; thus, the perceived image contrast is eventually decreased.

  10. 块体理论在阜康抽水蓄能电站地下厂房围岩稳定分析中的应用%Application of Block Theory in Analysis on Stability of Surrounding Rock of Underground Powerhouse,Fukang Pumped Storage Power Plant

    Institute of Scientific and Technical Information of China (English)

    贾巍; 于冲; 石广斌

    2015-01-01

    Through the calculation of the net sliding forces of the key blocks by the block theory, the suitability of the direction of the power-house axis of Fukang Pumped Storage Power Plant is demonstrated.The powerhouse axis should turn to northern direction, from the primary analysis on the stability of random blocks and positioning blocks, possibility of large-scaled and unstable block to be formed by fault in the powerhouse is little.The safety factors of individual blocks for shearing (pure friction) are lower than 1.0, In condition of provision of the systematic anchoring measures, or with local reinforcing support and slightly in consideration of rupture-resistance effect, the safety factor satisfies requirement.This presents that the proposed systematic anchoring measures at this stage is feasible and reasonable.%通过用块体理论计算洞周关键块体净滑力,论证了阜康抽水蓄能电站厂房轴线的方位是比较合适的,但宜向北方向偏转;从随机块体和定位块体稳定初步分析结果来看,断层在地下厂房中形成大规模不稳定的块体可能性较小,个别块体在抗剪(纯摩)安全系数小于1.0,但在系统锚固措施下或局部加强支护、略加考虑抗剪断效应,其安全系数均满足要求,说明本阶段设计拟定的系统锚固措施是可行的,也是合理的。

  11. Surrounding Risks

    Directory of Open Access Journals (Sweden)

    Mogens Steffensen

    2013-05-01

    Full Text Available Research in insurance and finance was always intersecting although they were originally and generally viewed as separate disciplines. Insurance is about transferring risks between parties such that the burdens of risks are borne by those who can. This makes insurance transactions a beneficial activity for the society. It calls on detection, modelling, valuation, and controlling of risks. One of the main sources of control is diversification of risks and in that respect it becomes an issue in itself to clarify diversifiability of risks. However, many diversifiable risks are not, by nature or by contract design, separable from non-diversifiable risks that are, on the other hand, sometimes traded in financial markets and sometimes not. A key observation is that the economic risk came before the insurance contract: Mother earth destroys and kills incidentally and mercilessly, but the uncertainty of economic consequences can be more or less cleverly distributed by the introduction of an insurance market.

  12. Is there an influence of the surrounding material on the response of the alanine dosimetry system?

    Science.gov (United States)

    Anton, Mathias; Kapsch, Ralf-Peter; Hackel, Thomas

    2009-04-01

    In a combined experimental and Monte Carlo study the possible influence of the surrounding material on the response of the alanine dosimetry system was investigated. The aim of this work was to estimate the uncertainties induced by the surroundings with respect to quality assurance measurements for radiotherapy, for example in humanoid phantoms. Six different materials were tested. The electron density range covered comprises the range present in human tissue. No significant influence of the surrounding material could be found for irradiations in the 60Co reference field of the Physikalisch-Technische Bundesanstalt (PTB).

  13. Analytical Modeling of Electric Field Distribution in Dual Material Junctionless Surrounding Gate MOSFETs

    Directory of Open Access Journals (Sweden)

    P. Suveetha Dhanaselvam

    2014-10-01

    Full Text Available In this paper, electric field distribution of the junctionless dual material surrounding gate MOSFETs (JLDMSG is developed. Junctionless is a device that has similar characteristics like junction based devices, but junctionless has a positive flatband voltage with zero electric field. In Surrounding gate MOSFETs gate material surrounds the channel in all direction , therefore it can overcome the short channel effects effectively than other devices. In this paper, surface potential and electric field distribution is modelled. The proposed surface potential model is compared with the existing central potential model. It is observed that the short channel effects (SCE is reduced and the performance is better than the existing method.

  14. Effects of annular air gaps surrounding an emplaced nuclear waste canister in deep geologic storage

    International Nuclear Information System (INIS)

    Annular air spaces surrounding an emplaced nuclear waste canister in deep geologic storage will have significant effects on the long-term performance of the waste form. Addressed specifically in this analysis is the influence of a gap on the thermal response of the waste package. Three dimensional numerical modeling predicts temperature effects for a series of parameter variations, including the influence of gap size, surface emissivities, initial thermal power generation of the canister, and the presence/absence of a sleeve. Particular emphasis is placed on determining the effects these variables have on the canister surface temperature. We have identified critical gap sizes at which the peak transient temperature occurs when gap widths are varied for a range of power levels. It is also shown that high emissivities for the heat exchanging surfaces are desirable, while that of the canister surface has the greatest influence. Gap effects are more pronounced, and therefore more effort should be devoted to optimal design, in situations where the absolute temperature of the near field medium is high. This occurs for higher power level emplacements and in geomedia with low thermal conductivities. Finally, loosely inserting a sleeve in the borehole effectively creates two gaps and drastically raises the canister peak temperature. It is possible to use these results in the design of an optimum package configuration which will maintain the canister at acceptable temperature levels. A discussion is provided which relates these findings to NRC regulatory considerations

  15. Using Bounding-Surrounding Boxes Method for Fish Tracking in Real World Underwater Observation

    Directory of Open Access Journals (Sweden)

    Yi-Haur Shiau

    2013-07-01

    Full Text Available The purpose of this paper is to present a rapid and efficient fish tracking method suitable for real world automatic underwater fish observation. Based on fish tracking, biologists are able to observe fish and their ecological environment. A distributed real-time underwater video stream system has been developed in Taiwan for large-scale, long-term ecological observation. In addition, not only does the system archive video data, but also incorporates data analysis. However, it is difficult to discriminate moving fish from drift water plants due to the severe drift of water plants caused by the water flow in real world underwater environments. Thus, fish tracking is complicated in unconstrained water. In order to overcome this problem, we propose a bounding-surrounding boxes method, which enables integration with state-of-the-art tracking methods for fish tracking in this paper. According to the method, fixing cameras must be used so that the moving fish are classified as foreground objects and are tracked, whereas the drifting water plants are classified as the background objects and are removed from the tracked objects. It enables the efficient, rapid removal of irrelevant information (non-fish objects from large-scale fish video data. Experimental results show that the proposed method is able to achieve high accuracy.

  16. A distributed code for colour in natural scenes derived from centre-surround filtered cone signals

    Directory of Open Access Journals (Sweden)

    Christian Johannes Kellner

    2013-09-01

    Full Text Available In the retina of trichromatic primates, chromatic information is encoded in an opponent fashion and transmitted to the lateral geniculate nucleus (LGN and visual cortex via parallel pathways. Chromatic selectivities of neurons in the LGN form two separate clusters, corresponding to two classes of cone opponency. In the visual cortex, however, the chromatic selectivities are more distributed, which is in accordance with a population code for colour. Previous studies of cone signals in natural scenes typically found opponent codes with chromatic selectivities corresponding to two directions in colour space. Here we investigated how the nonlinear spatiochromatic filtering in the retina influences the encoding of colour signals. Cone signals were derived from hyperspectral images of natural scenes and pre-processed by centre-surround filtering and rectification, resulting in parallel ON and OFF channels. Independent Component Analysis on these signals yielded a highly sparse code with basis functions that showed spatio-chromatic selectivities. In contrast to previous analyses of linear transformations of cone signals, chromatic selectivities were not restricted to two main chromatic axes, but were more continuously distributed in colour space, similar to the population code of colour in the early visual cortex. Our results indicate that spatiochromatic processing in the retina leads to a more distributed and more efficient code for natural scenes.

  17. Lipids and glycosphingolipids in caveolae and surrounding plasma membrane of primary rat adipocytes.

    Science.gov (United States)

    Ortegren, Unn; Karlsson, Margareta; Blazic, Natascha; Blomqvist, Maria; Nystrom, Fredrik H; Gustavsson, Johanna; Fredman, Pam; Strålfors, Peter

    2004-05-01

    We have made a comprehensive and quantitative analysis of the lipid composition of caveolae from primary rat fat cells and compared the composition of plasma membrane inside and outside caveolae. We isolated caveolae from purified plasma membranes using ultrasonication in carbonate buffer to disrupt the membrane, or extraction with nonionic detergent, followed by density gradient ultracentrifugation. The carbonate-isolated caveolae fraction was further immunopurified using caveolin antibodies. Carbonate-isolated caveolae were enriched in cholesterol and sphingomyelin, and the concentration was three- and twofold higher, respectively, in caveolae compared to the surrounding plasma membrane. The concentration of glycerophospholipids was similar suggesting that glycerophospholipids constitute a constant core throughout the plasma membrane. The composition of detergent-insoluble fractions of the plasma membrane was very variable between preparations, but strongly enriched in sphingomyelin and depleted of glycerophospholipids compared to carbonate-isolated caveolae; indicating that detergent extraction is not a suitable technique for caveolae preparation. An average adipocyte caveola contained about 22 x 10(3) molecules of cholesterol, 7.5 x 10(3) of sphingomyelin and 23 x 10(3) of glycerophospholipid. The glycosphingolipid GD3 was highly enriched in caveolae, whereas GM3, GM1 and GD1a were present inside as well as outside the caveolae membrane. GD1b, GT1b, GM2, GQ1b, sulfatide and lactosylceramide sulfate were not detected in caveolae.

  18. Comparison of soil and forest floor properties of floodplain and surrounding forests in Igneada, Turkey.

    Science.gov (United States)

    Tecimen, Huseyin Baris; Kavgaci, Ali

    2010-01-01

    In this study some soil and forest floor characteristics of floodplain forest, thermophile forest and sand dune were investigated at Igneada, Turkey. In this context, surface soil samples were analyzed and compared to each other in the extension of soil physical, chemical properties and as plant nutrition environment. To investigate the soil characteristics soil samples were collected from 48 sampling point. The distribution of the soils revealed that remarkably physical soil properties figure the ordination of soils in principal component analysis (PCA). We concluded that floodplain forests have quite different soil properties from the thermophile forest and sand dunes under the continuous effect of surrounding thermophile forest land with less sandy proportion to soil texture 52.4 at floodplain forest, 64.0% at thermophile forest and 91.0% at sand dunes and highly organic carbon 5.619, 4.191 and 0.478% respectively at 0-5 cm depth and total nitrogen content 0.213, 0.078 and 0.056% for floodplain forest > thermophile forest > sand dune soils, respectively. Weight and organic matter contents of forest floor were significantly higher in the thermophile forests. PMID:20648824

  19. An aerial radiological survey of the Fernald Environmental Management Project and surrounding area, Fernald, Ohio

    International Nuclear Information System (INIS)

    An aerial radiological survey was conducted from May 17--22, 1994, over a 36 square mile (93 square kilometer) area centered on the Fernald Environmental Management Project located in Fernald, Ohio. The purpose of the survey was to detect anomalous gamma radiation in the environment surrounding the plant. The survey was conducted at a nominal altitude of 150 feet (46 meters) with a line spacing of 250 feet (76 meters). A contour map of the terrestrial gamma exposure rate extrapolated to 1 meter (3.3 feet) above ground was prepared and overlaid on an aerial photograph of the area. Analysis of the data for man made sources showed five sites within the boundaries of the Fernald Environmental Management Project having elevated readings. The exposure rates outside the plant boundary were typical of naturally occurring background radiation. Soil samples and pressurized ion chamber measurements were obtained at four locations within the survey boundaries to supplement the aerial data. It was concluded that although the radionuclides identified in the high-exposure-rate areas are naturally occurring, the levels encountered are greatly enhanced due to industrial activities at the plant

  20. An aerial radiological survey of the Fernald Environmental Management Project and surrounding area, Fernald, Ohio

    Energy Technology Data Exchange (ETDEWEB)

    Phoenix, K.A.

    1997-04-01

    An aerial radiological survey was conducted from May 17--22, 1994, over a 36 square mile (93 square kilometer) area centered on the Fernald Environmental Management Project located in Fernald, Ohio. The purpose of the survey was to detect anomalous gamma radiation in the environment surrounding the plant. The survey was conducted at a nominal altitude of 150 feet (46 meters) with a line spacing of 250 feet (76 meters). A contour map of the terrestrial gamma exposure rate extrapolated to 1 meter (3.3 feet) above ground was prepared and overlaid on an aerial photograph of the area. Analysis of the data for man made sources showed five sites within the boundaries of the Fernald Environmental Management Project having elevated readings. The exposure rates outside the plant boundary were typical of naturally occurring background radiation. Soil samples and pressurized ion chamber measurements were obtained at four locations within the survey boundaries to supplement the aerial data. It was concluded that although the radionuclides identified in the high-exposure-rate areas are naturally occurring, the levels encountered are greatly enhanced due to industrial activities at the plant.

  1. Geochemistry and environmental threats of soils surrounding an abandoned mercury mine.

    Science.gov (United States)

    Bori, Jaume; Vallès, Bettina; Navarro, Andrés; Riva, Maria Carme

    2016-07-01

    The closure of mercury mining areas is generally associated with a release of Hg and other metals into the environment due to the abandonment of mining wastes. Because of their potential toxic properties, the mobilization of particulate and soluble metal species is of major concern. In the present study, the environmental risks posed by soils surrounding an abandoned mercury mining area in Valle del Azogue (Almeria, Spain) are assessed through the determination of physical-chemical parameters, the quantification of metal concentrations, and the application of aquatic and terrestrial ecotoxicity bioassays. Chemical analysis of soil samples revealed concentrations of Hg, As, Ba, Pb, Sb, and Zn above international intervention values. Results from terrestrial tests showed detrimental effects in all studied organisms (Eisenia foetida, Folsomia candida, and different plant species) and revealed the avoidance response of earthworms as the most sensitive endpoint. Surprisingly, the most toxic samples were not the ones with higher metal contents but the ones presenting higher electrical conductivity. Aquatic ecotoxicity tests with Vibrio fischeri, Raphidocelis subcapitata, Daphnia magna, and Danio rerio were in accordance with terrestrial tests, confirming the need to couple environmental chemistry with ecotoxicological tools for the proper assessment of metal-contaminated sites. In view of the results, a remediative intervention of the studied area is recommended. PMID:26996905

  2. Ecological risk assessment of heavy metals in soils surrounding oil waste disposal areas.

    Science.gov (United States)

    Xu, Jianling; Wang, Hanxi; Liu, Yuanyuan; Ma, Mengchao; Zhang, Tian; Zheng, Xiaoxue; Zong, Meihan

    2016-02-01

    More attention is being devoted to heavy metal pollution because heavy metals can concentrate in higher animals through the food chain, harm human health and threaten the stability of the ecological environment. In this study, the effects of heavy metals (Cu, Cr, Zn, Pb, Cd, Ni and Hg) emanating from oil waste disposal on surrounding soil in Jilin Province, China, were investigated. A potential ecological risk index was used to evaluate the damage of heavy metals and concluded that the degree of potential ecological damage of heavy metals can be ranked as follows: Hg > Cd > Pb > Cu > Ni > Cr > Zn. The average value of the potential ecological harm index (Ri) is 71.93, thereby indicating light pollution. In addition, this study researched the spatial distribution of soil heavy metals by means of ArcGIS (geographic information system) spatial analysis software. The results showed that the potential ecological risk index (R) of the large value was close to the distance from the oil waste disposal area; it is relatively between the degree of heavy metals in soil and the distance from the waste disposal area.

  3. The IC 5146 star forming complex and its surroundings with 2MASS, WISE and Spitzer

    Science.gov (United States)

    Nunes, N. A.; Bonatto, C.; Bica, E.

    2016-02-01

    Throughout the last decade sensitive infrared observations obtained by the Spitzer Space Telescope significantly increased the known population of YSOs associated with nearby molecular clouds. With such a census recent studies have characterized pre-main sequence stars (PMS) and determined parameters from different wavelengths. Given the restricted Spitzer coverage of some of these clouds, relative to their extended regions, these YSO populations may represent a limited view of star formation in these regions. We are taking advantage of mid-infrared observations from the NASA Wide Field Infrared Survey Explorer (WISE), which provides an all sky view and therefore full coverage of the nearby clouds, to assess the degree to which their currently known YSO population may be representative of a more complete population. We extend the well established classification method of the Spitzer Legacy teams to archived WISE observations. We have adopted 2MASS photometry as a "standard catalogue" for comparisons. Besides the massive embedded cluster IC 5146 we provide a multiband view of five new embedded clusters in its surroundings that we discovered with WISE. In short, the analysis involves the following for the presently studied cluster sample: (i) extraction of 2MASS/WISE/Spitzer photometry in a wide circular region; (ii) field-star decontamination to enhance the intrinsic Colour-magnitude diagram (CMD) morphology (essential for a proper derivation of reddening, age, and distance from the Sun); and (iii) construction of Colour-magnitude filters, for more contrasted stellar radial density profiles (RDPs).

  4. GRB 081007 and GRB 090424: the surrounding medium, outflows and supernovae

    CERN Document Server

    Jin, Zhi-Ping; Della Valle, Massimo; Ferrero, Patrizia; Fugazza, Dino; Malesani, Daniele; Melandri, Andrea; Pian, Elena; Salvaterra, Ruben; Bersier, David; Campana, Sergio; Cano, Zach; D'Avanzo, Paolo; Fynbo, Johan P U; Guidorzi, Cristiano; Haislip, Joshua B; Hjorth, Jens; LaCluyze, Aaron P; Marconi, Gianni; Mazzali, Paolo A; Piranomonte, Silvia; Reichart, Daniel E; Tagliaferri, Gianpiero; Tanvir, Nial R; Valenti, Stefano; Vergani, Susanna D; Vestrand, Thomas; Walker, Emma S; Wozniak, Przemyslaw

    2013-01-01

    We discuss the results of the analysis of multi-wavelength data for the afterglows of GRB 081007 and GRB 090424, two bursts detected by Swift. One of them, GRB 081007, also shows a spectroscopically confirmed supernova, SN 2008hw, which resembles SN 1998bw in its absorption features, while the maximum luminosity is only about half as large as that of SN 1998bw. Bright optical flashes have been detected in both events, which allows us to derive solid constraints on the circumburst-matter density profile. This is particularly interesting in the case of GRB 081007, whose afterglow is found to be propagating into a constant-density medium, yielding yet another example of a GRB clearly associated with a massive star progenitor which did not sculpt the surroundings with its stellar wind. There is no supernova component detected in the afterglow of GRB 090424, likely due to the brightness of the host galaxy, comparable to the Milky Way. We show that the afterglow data are consistent with the presence of both forward...

  5. Ecological risk assessment of heavy metals in soils surrounding oil waste disposal areas.

    Science.gov (United States)

    Xu, Jianling; Wang, Hanxi; Liu, Yuanyuan; Ma, Mengchao; Zhang, Tian; Zheng, Xiaoxue; Zong, Meihan

    2016-02-01

    More attention is being devoted to heavy metal pollution because heavy metals can concentrate in higher animals through the food chain, harm human health and threaten the stability of the ecological environment. In this study, the effects of heavy metals (Cu, Cr, Zn, Pb, Cd, Ni and Hg) emanating from oil waste disposal on surrounding soil in Jilin Province, China, were investigated. A potential ecological risk index was used to evaluate the damage of heavy metals and concluded that the degree of potential ecological damage of heavy metals can be ranked as follows: Hg > Cd > Pb > Cu > Ni > Cr > Zn. The average value of the potential ecological harm index (Ri) is 71.93, thereby indicating light pollution. In addition, this study researched the spatial distribution of soil heavy metals by means of ArcGIS (geographic information system) spatial analysis software. The results showed that the potential ecological risk index (R) of the large value was close to the distance from the oil waste disposal area; it is relatively between the degree of heavy metals in soil and the distance from the waste disposal area. PMID:26832722

  6. Eargle's the microphone book from mono to stereo to surround : a guide to microphone design and application

    CERN Document Server

    Rayburn, Ray A

    2012-01-01

    Eargle's Microphone Book is the only guide you will ever need for the latest in microphone technology, application and technique. This new edition features more on microphone arrays and wireless microphones, new material on digital models; the latest developments in surround; expanded advice on studio set up, recording and mic selection. Ray A. Rayburn provides detailed analysis of the different types of microphones available and addresses their application through practical examples of actual recording sessions and studio operations. The book takes you into the stu

  7. Inner cauchy horizon of axisymmetric and stationary black holes with surrounding matter in einstein-maxwell theory.

    Science.gov (United States)

    Ansorg, Marcus; Hennig, Jörg

    2009-06-01

    We study the interior electrovacuum region of axisymmetric and stationary black holes with surrounding matter and find that there exists always a regular inner Cauchy horizon inside the black hole, provided the angular momentum J and charge Q of the black hole do not vanish simultaneously. In particular, we derive an explicit relation for the metric on the Cauchy horizon in terms of that on the event horizon. Moreover, our analysis reveals the remarkable universal relation (8piJ);{2}+(4piQ;{2});{2}=A;{+}A;{-}, where A+ and A- denote the areas of event and Cauchy horizon, respectively. PMID:19658851

  8. Analysing land cover and land use change in the Matobo National Park and surroundings in Zimbabwe

    Science.gov (United States)

    Scharsich, Valeska; Mtata, Kupakwashe; Hauhs, Michael; Lange, Holger; Bogner, Christina

    2016-04-01

    Natural forests are threatened worldwide, therefore their protection in National Parks is essential. Here, we investigate how this protection status affects the land cover. To answer this question, we analyse the surface reflectance of three Landsat images of Matobo National Park and surrounding in Zimbabwe from 1989, 1998 and 2014 to detect changes in land cover in this region. To account for the rolling countryside and the resulting prominent shadows, a topographical correction of the surface reflectance was required. To infer land cover changes it is not only necessary to have some ground data for the current satellite images but also for the old ones. In particular for the older images no recent field study could help to reconstruct these data reliably. In our study we follow the idea that land cover classes of pixels in current images can be transferred to the equivalent pixels of older ones if no changes occurred meanwhile. Therefore we combine unsupervised clustering with supervised classification as follows. At first, we produce a land cover map for 2014. Secondly, we cluster the images with clara, which is similar to k-means, but suitable for large data sets. Whereby the best number of classes were determined to be 4. Thirdly, we locate unchanged pixels with change vector analysis in the images of 1989 and 1998. For these pixels we transfer the corresponding cluster label from 2014 to 1989 and 1998. Subsequently, the classified pixels serve as training data for supervised classification with random forest, which is carried out for each image separately. Finally, we derive land cover classes from the Landsat image in 2014, photographs and Google Earth and transfer them to the other two images. The resulting classes are shrub land; forest/shallow waters; bare soils/fields with some trees/shrubs; and bare light soils/rocks, fields and settlements. Subsequently the three different classifications are compared and land changes are mapped. The main changes are

  9. Site Cleanup of Radioactive Isotope Container Rinsing Pool and Surrounding Environment

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Radioactive isotope container rinsing pool and surrounding environmental site was a place of fabrication of container, and package, transportation and storage of radioactive isotopes. A heavy contamination existed in this area for burying of some radioactive wastes.

  10. Review of roadway control in soft surrounding rock under dynamic pressure

    Institute of Scientific and Technical Information of China (English)

    侯朝炯

    2003-01-01

    The basic characteristics of the soft rock roadway under the dynamic pressure are analyzed. At the same time, the three fundamental approaches for controlling the surrounding rock are proposed, which are improving the surrounding rock strength, lowering the rock mass stress and selecting the reasonable supporting technology. The research results are elucidated, including the distribution of the surrounding rock plastic zone, the movement and damage of the surrounding rock under the dynamic pressure, controlling the floor heave through reinforcing the roadway walls and corners, the new route to develop the roadway metal supporting technique, the key theory and technique for the bolt supporting in the coal roadway, the performance and prospect of the ZKD high-water-content quick-setting material, and so on. Finally, some personally views are put forward about the roadway metal supporting, bolt supporting, new material and the stress-relief under the high stress condition.

  11. Stresses and Shear Fracture Zone of Jinshazhou Tunnel Surrounding Rock in Rich Water Region

    Institute of Scientific and Technical Information of China (English)

    ZHENG Jun-jie; LOU Xiao-ming

    2008-01-01

    Field evidence has shown that large-scale and unstable discontinuous planes in the rock mass surrounding tunnels in rich water region are probably generated after excavation. The tunnel surrounding rock was divided into three zones, including elastic zone, plastic damage zone and shear fracture zone fof assessing the stability of the tunnel surrounding rock. By local hydrogeology, the stresses of surrounding rock of Jinshazhou circular tunnel was analyzed and the stress solutions on the elastic and plastic damage zones were obtained by applying the theories of fluid-solid coupling and elasto-plastic damage mechanics. The shear fracture zone generated by joints was studied and its range was determined by using Mohr-Coulomb strength criterion. Finally, the correctness of the theoretical results was validated by comparing the scopes of shear fracture zones calculated in this paper with those from literature.

  12. Tropical Storm Ernesto Aerial Photography: Rapid Response Imagery of the Surrounding Regions After Landfall

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The imagery posted on this site is of the surrounding regions after Tropical Storm Ernesto made landfall. The aerial photography missions were conducted by the NOAA...

  13. The relation between residential property and its surroundings and day- and night-time residential burglary

    NARCIS (Netherlands)

    Montoya, Lorena; Junger, Marianne; Ongena, Yfke

    2016-01-01

    This article examines how residential property and its surroundings influence day- and night-time residential burglary. Crime Prevention Through Environmental Design (CPTED) principles of territoriality, surveillance, access control, target hardening, image maintenance, and activity support underpin

  14. Hurricane Ike Aerial Photography: Rapid ResponseImagery of the Surrounding Regions After Landfall

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The imagery posted on this site is of the surrounding regionsafter Hurricane Ike made landfall. The aerial photography missions wereconducted by the NOAA Remote...

  15. Hurricane Dennis Aerial Photography: Draft Image Mosaics of the Florida Panhandle and Surrounding Regions After Landfall

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The imagery posted on this site is of the Florida panhandle and surrounding regions after Hurricane Dennis made landfall. The regions photographed range from...

  16. Effect of surface contamination on osseointegration of dental implants surrounded by circumferential bone defects.

    LENUS (Irish Health Repository)

    Mohamed, Seif

    2010-05-01

    This study was designed to evaluate the effect of surface contamination on osseointegration of dental implants surrounded by a circumferential bone defect and to compare osseointegration around Osseotite with that around Nanotite implants.

  17. Effect of Stresses and Strains of Roadway Surrounding Rocks on Borehole Airtightness

    Directory of Open Access Journals (Sweden)

    WU Wei

    2016-02-01

    Full Text Available At present, many high gas and outburst mines have poor gas drainage effects. An important reason influencing the gas drainage effect is a poor hole-sealing effect. Most studies on gas drainage borehole sealing focus on local and foreign borehole sealing methods, borehole sealing equipment, and borehole sealing materials. Numerical simulations of initial drilling sealing depth are insufficient because studies on this subject are few. However, when the initial sealing depth of the borehole is not chosen reasonably, air can enter the gas drainage drill hole through the circumferential crack of roadway surrounding rocks under the influence of suction pressure of the drainage system. This phenomenon ultimately affects the hole-sealing effect. To improve the drilling hole sealing of gas drainage boring, we deduced the expression formulas of the crushing zone, plastic zone, and elastic zone around the coal-seam floor stone drift and conducted a stress–strain analysis of the coal-seam floor stone drift of the 2145 working surfaces of the Sixth Coal Mine of Hebi Coal Mine Group Company by using theoretical analysis, numerical simulation, and on-scene verification. Finally, we obtain the initial drilling sealing depth, which is a main contribution of this study. The results prove the following. The performed hole-sealing process with an initial drilling sealing depth of 8 m has a gas drainage efficiency of 55%. Compared with the previous 6.8 m initial drilling sealing depth with a gas drainage efficiency of less than 30%, which was adopted by the mine, the initial sealing depth of 8 m chosen in the numerical simulation is reasonable and conforms to the actual situation on the spot. Therefore, the initial drilling sealing depth chosen in the numerical simulation will produce practical and effective guidance to study the field hole-sealing depth.

  18. Niches of dominant fish in the waters surrounding the Taishan Islands, China

    Science.gov (United States)

    Yang, Lu; Chen, Jie; Yang, Shengyun; Zhong, Huiqi; Ju, Peilong; Yang, Shunliang; Sun, Qinqin; Chen, Mingru

    2016-07-01

    An index of relative importance (IRI) was employed to screen for dominant fish in the waters surrounding the Taishan Islands, China, using data from four seasonal trawl surveys undertaken between 2012 and 2013. Niche breadth and niche overlap were measured using the Feinsinger and Morisita-Horn indices, respectively, and the characteristics and seasonal variations in the niches of dominant fish were assessed via non-metric multidimensional scaling (NMDS) and cluster analysis. A total of 80 fish species, including 16 dominant species, were recorded. Only Amblychaeturichthys hexanema was dominant in all seasons. According to niche breadth values and NMDS, the 16 dominant species were grouped into the following three types: (1) wide niche breadth species, including Cynoglossus macrolepidotus, A. hexanema, and Trypauchen vagina, among others; (2) medium niche breadth species, including Setipinna taty and Johnius belangerii; and (3) narrow niche breadth species, including Atrobucca nibe and Coilia mystus. Most species with a wider niche breadth were demersal fish with a lower swimming capability and even distribution. The niche breadth of migrating fish was narrower than that of settled fish. At a given spatial scale, fish with stronger swimming capabilities had a narrower niche breadth. Niche overlap, which is associated with niche specialization, ranged from 0.000 to 0.886 and had an annual mean value of 0.314. In summer and autumn, niche overlap was relatively high within species of the Sciaenidae family and within species of the Gobiidae in autumn. Differences in thermophily, feeding habits, food organism abundance/distribution and predator-prey relationships affected the niche overlap of fish in this area. Cluster analysis revealed that species with the narrowest niche breadth and lowest niche overlap values usually displayed lower aggregation and greater distribution differences compared with other species.

  19. Neural mechanisms of surround attenuation and distractor competition in visual search

    OpenAIRE

    Böhler, Nico; Tsotsos, John K.; Schoenfeld, Mircea A.; Heinze, Hans-Jochen; Hopf, Jens-Max

    2011-01-01

    Visual attention biases relevant processing in the visual system by amplifying relevant or attenuating irrelevant sensory input. A potential signature of the latter operation, referred to as surround attenuation, has recently been identified in the electromagnetic brain response of human observers performing visual search. It was found that a zone of attenuated cortical excitability surrounds the target when the search required increased spatial resolution for item discrimination. Here we add...

  20. The influence of the rammed stone column formation on strength parameters of the surrounding soil

    OpenAIRE

    Kwiecień, Sławomir; Kanty, Piotr; Sękowski, Jerzy

    2014-01-01

    This paper presents the results of field tests performed to examine the influence of the rammed stone column formation process on the surrounding soil. The influence is expressed by cohesion and internal friction angle changes. These parameters were determined in cone penetration test (CPTU) performed during and after the stone column formation process. The conducted tests have shown that the process of column formation affects the strength parameters of the surrounding soil. These changes ar...

  1. Fovea-periphery axis symmetry of surround modulation in the human visual system.

    Directory of Open Access Journals (Sweden)

    Lauri Nurminen

    Full Text Available A visual stimulus activates different sized cortical area depending on eccentricity of the stimulus. Here, our aim is to understand whether the visual field size of a stimulus or cortical size of the corresponding representation determines how strongly it interacts with other stimuli. We measured surround modulation of blood-oxygenation-level-dependent signal and perceived contrast with surrounds that extended either towards the periphery or the fovea from a center stimulus, centered at 6° eccentricity. This design compares the effects of two surrounds which are identical in visual field size, but differ in the sizes of their cortical representations. The surrounds produced equally strong suppression, which suggests that visual field size of the surround determines suppression strength. A modeled population of neuronal responses, in which all the parameters were experimentally fixed, captured the pattern of results both in psychophysics and functional magnetic resonance imaging. Although the fovea-periphery anisotropy affects nearly all aspects of spatial vision, our results suggest that in surround modulation the visual system compensates for it.

  2. Elemental analysis of soils and Salix polaris in the town of Pyramiden and its surroundings (Svalbard).

    Science.gov (United States)

    Krajcarová, Lucie; Novotný, Karel; Chattová, Barbora; Elster, Josef

    2016-05-01

    The contents of elements in the top soil (upper 5 cm) and deeper soil (5 to 10 cm) layers and in Salix polaris (leaves and stem) from the former Soviet mining town of Pyramiden and its close vicinity on the Svalbard archipelago were determined. The analyses covered major and trace elements, including heavy metals, in order to describe anthropogenic impacts related to the management of the mining town. Soil samples and plant tissues were analysed from 13 localities across and close to town vicinity. The plant ground cover of all sampling points was determined, and plant tissues (leaves and stem) were collected. Higher contents of Cd (3-11 mg kg(-1)) and Mo (11-33 mg kg(-1)) were detected in the soils. With relation to the world average concentration of metals in soils, the geo-accumulation indexes (Igeo) and the level of pollution of the analysed soils were classified into seven pollution grades. The soils of the studied localities were usually unpolluted (grade 1) when analysed for metals, with the soil pollution grades 4-6 identified only for Cd and Mo (moderately to strongly polluted). In Salix polaris, excessive amounts of Fe (60-1520 mg kg(-1)), Zn (80-1050 mg kg(-1)), Cd (0.2-5.5 mg kg(-1)) and Cr (0-3.6 mg kg(-1)) were observed. The Igeo of these elements, compared with values considered sufficient for plants, showed pollution grades from 2 to 6. The pollution load index (PLI) ranged between 0.49 and 1.01. Only one locality could be considered polluted having a PLI higher than 1. Plant/soil transfer factors (TF) for trace metals decreased in the following order: Zn > Cu > Cd > Mn > Ni > As > Mo > Pb > Co > Al > Cr > Fe. The principal contribution of this study consists in the assessment of the contamination of soils and plants by toxic heavy metals in an otherwise pristine environment of the Svalbard archipelago related to urban/industrial activities. PMID:26867690

  3. Grasping the TLRP Nettle: Preliminary Analysis and Some Enduring Issues Surrounding the Improvement of Learning Outcomes

    Science.gov (United States)

    James, Mary; Brown, Sally

    2005-01-01

    The ESRC Teaching and Learning Research Programme is the largest ever programme of educational research in the UK. This article reports the purposes, processes, outcomes and issues arising from cross-programme thematic work on the conceptualization of, and research into, 'enhancing learning outcomes' which is a key aim of the programme. Early…

  4. Economic and Time-Sensitive Issues Surrounding CCS: A Policy Analysis.

    Science.gov (United States)

    Maddali, Vijay; Tularam, Gurudeo Anand; Glynn, Patrick

    2015-08-01

    Are the existing global policies on combating global warming via the carbon capture and storage (CCS) method significant enough to curtail the temperature rise on time? We argue that it is already too late to have any reliance on CCS. The current status of CCS is that it is plagued by technical uncertainties, infrastructure, financial, and regulatory issues. The technology is far from maturity and, hence, commercialization. Simulations conducted in this work suggest that the relevance of CCS is completely defied if the annual emission growth rate is in excess of 2% between the years of 2015 and 2040. At such a growth rate, the annual emissions reduction between 2040 and 2100 will need to be in the vicinity of 5.5% by the year 2100. Considering an average annual emissions growth rate of 2.5% over the past decade, it seems unlikely that the emissions could be contained to a 2% growth level. CCS in its current shape and form is at odds with the economics of its implementation and the time in hand with which to play a significant role in a carbon mitigation strategy. There is an urgent need to rethink policies and strategies to combat global warming to at least some degree. PMID:26114417

  5. BVRIJHK photometry and proper motion analysis of NGC 6253 and the surrounding field

    CERN Document Server

    Montalto, M; Desidera, S; Platais, I; Carraro, G; Momany, Y; De Marchi, F; Recio-Blanco, A

    2009-01-01

    Context. We present a photometric and astrometric catalog of 187963 stars located in the field around the old super-metal-rich Galactic open cluster NGC 6253. The total field-of-view covered by the catalog is 34' x 33'. In this field, we provide CCD BVRI photometry. For a smaller region close to the cluster's center, we also provide near-infrared JHK photometry. Aims. We analyze the properties of NGC 6253 by using our new photometric data and astrometric membership. Methods. In June 2004, we targeted the cluster during a 10 day multi-site campaign, which involved the MPG/ESO 2.2m telescope with its wide-field imager and the Anglo-Australian 3.9m telescope, equipped with the IRIS2 near-infrared imager. Archival CCD images of NGC 6253 were used to derive relative proper motions and to calculate the cluster membership probabilities. Results. We have refined the cluster's fundamental parameters, deriving (V_0-M_v)=11.15, E(B - V)=0.15, E(V - I)=0.25, E(V - J)=0.50, and E(V - H)=0.55. The color excess ratios obtai...

  6. Determination, speciation and distribution of mercury in soil in the surroundings of a former chlor-alkali plant: assessment of sequential extraction procedure and analytical technique

    OpenAIRE

    Frentiu, Tiberiu; Pintican, Bogdan Petru; Butaciu, Sanziana; Mihaltan, Alin Ironim; Ponta, Michaela; Frentiu, Maria

    2013-01-01

    Background The paper presents the evaluation of soil contamination with total, water-available, mobile, semi-mobile and non-mobile Hg fractions in the surroundings of a former chlor-alkali plant in connection with several chemical soil characteristics. Principal Component Analysis and Cluster Analysis were used to evaluate the chemical composition variability of soil and factors influencing the fate of Hg in such areas. The sequential extraction EPA 3200-Method and the determination technique...

  7. Study on calculation of rock pressure for ultra-shallow tunnel in poor surrounding rock and its tunneling procedure

    Institute of Scientific and Technical Information of China (English)

    Xiaojun Zhou; Jinghe Wang; Bentao Lin

    2014-01-01

    A computational method of rock pressure applied to an ultra-shallow tunnel is presented by key block theory, and its mathematical formula is proposed according to a mechanical tunnel model with super-shallow depth. Theoretical analysis shows that the tunnel is subject to asymmetric rock pressure due to oblique topography. The rock pressure applied to the tunnel crown and sidewall is closely related to the surrounding rock bulk density, tunnel size, depth and angle of oblique ground slope. The rock pressure applied to the tunnel crown is much greater than that to the sidewalls, and the load applied to the left side-wall is also greater than that to the right sidewall. Mean-while, the safety of the lining for an ultra-shallow tunnel in strata with inclined surface is affected by rock pressure and tunnel support parameters. Steel pipe grouting from ground surface is used to consolidate the unfavorable surrounding rock before tunnel excavation, and the reinforcing scope is proposed according to the analysis of the asymmetric load induced by tunnel excavation in weak rock with inclined ground surface. The tunneling procedure of bench cut method with pipe roof protection is still discussed and carried out in this paper according to the special geological condition. The method and tunneling procedure have been successfully utilized to design and drive a real expressway tunnel. The practice in building the super-shallow tunnel has proved the feasibility of the calculation method and tunneling procedure presented in this paper.

  8. Surrounding greenness, proximity to city parks and pregnancy outcomes in Kaunas cohort study.

    Science.gov (United States)

    Grazuleviciene, Regina; Danileviciute, Asta; Dedele, Audrius; Vencloviene, Jone; Andrusaityte, Sandra; Uždanaviciute, Inga; Nieuwenhuijsen, Mark J

    2015-05-01

    There is increasing evidence that green space can improve the health and well-being of urban residents. However, there has been no consistent evidence of the effect of city parks on reproductive health. We investigated whether surrounding greenness levels and/or distance to city parks affect birth outcomes. This study was based on 3292 singleton live-births from the Kaunas birth cohort, Lithuania (2007-2009), who were enrolled in the FP7 PHENOTYPE project study. Residential surrounding greenness level was ascertained as average of satellite-based normalized difference vegetation index (NDVI) within buffers of 100 m, 300 m, and 500 m of each maternal home and distance to a city park was defined as distance to boundaries of the nearest city park. For each indicator of green space exposure, linear or logistic regression models were constructed to estimate change in birth outcomes adjusted for relevant covariates. An increase in distance to a city parks was associated with an increase in risk of preterm birth and decrease of gestational age. We found a statistically significant association between low surrounding greenness and term low birth weight. After assessing effect modification based on the low surrounding greenness (NDVI-5001000 m), we found increased risks for low birth weight (OR 2.23, 1.20-4.15), term low birth weight (OR 2.97, 1.04-8.45) and preterm birth (OR 1.77, 1.10-2.81) for subjects with low surrounding greenness and farther distance from a park. Both higher surrounding greenness level and proximity to park have beneficial effects on pregnancy outcomes. A beneficial park effect on foetal growth is most apparent in the environment with low surrounding greenness level. Further investigation is needed to confirm this association. PMID:25757723

  9. Characterization of fly ash from a power plant and surroundings by micro-Raman spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Guedes, A.; Valentim, B. [Centro de Geologia da Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal); Prieto, A.C.; Sanz, A. [Departamento de Fisica de la Materia Condensada, Cristalografia y Mineralogia. Universidad de Valladolid, Valladolid (Spain); Flores, D.; Noronha, F. [Centro de Geologia da Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal); Departamento de Geologia da Faculdade de Ciencias, Rua do Campo Alegre 687, 4169-007 Porto (Portugal)

    2008-02-01

    Fly ash samples were collected from a Portuguese power plant that burns low-sulphur coals from South Africa, U.S.A., Colombia, and Australia. The fly ashes were collected from the hoppers of the economizers, air heaters, electrostatic precipitators, and from the stack. The power plant air monitoring system was also sampled. The fly ash characterization was conducted by micro-Raman spectroscopy (MRS). The micro-Raman spectroscopic analysis permitted an efficient identification and characterization of different inorganic and organic materials present in fly ash: quartz, hematite, magnetite, calcite, glass, aluminium and calcium oxides, and different types of organic constituents. The study of the structural evolution of the unburned carbon/char material during their path through the power plant, though the use of Raman spectra and Raman parameters reveal that despite the high temperatures they reached, these materials are still structurally disordered. However, a structural evolution occurs in the char from the economizer up to the electrostatic precipitators where the char is structurally more disordered. The different features of the Raman spectra observed for carbon particles collected from the stack, together with the high range of variation of the Raman parameters, confirm the existence of different carbon particles in the stack, i.e., char and others (probably soot). The filters from the surroundings contain a variety of carbon particles with Raman parameters different from the ones obtained in the fly ash hoppers and stack. These are diesel particles as indicated by the values of W{sub D1}, FWHM{sub D1}, FWHM{sub G}, W{sub G} and ID1/IG obtained. (author)

  10. Luobei graphite mines surrounding ecological environment monitoring based on high-resolution satellite data

    Science.gov (United States)

    Zhang, Lifeng; Liu, Xiaosha; Wan, Huawei; Liu, Xiaoman

    2014-11-01

    Graphite is one of the important industrial mineral raw materials, but the high content of heavy metals in tailings may cause soil pollution and other regional ecological environmental problems. Luobei has already become the largest production base of graphite. To find out the ecological situation in the region, further ecological risk analysis has been carried out. Luobei graphite mine which is located in Yabdanhe basin has been selected as the study area, SVM classifiers method with the support of GF-1 Satellite remote sensing data has been used, which is the first high-resolution earth observation satellite in China. The surrounding ecological environment was monitored and its potential impact on the ecological environment was analyzed by GIS platform. The results showed that the Luobei graphite mine located Yadanhe basin covers an area of 499.65 km2, the main types of forest ecosystems ( 44.05% of the total basin area ), followed by agricultural area( 35.14% ), grass area( 15.52% ), residential area ( 4.34% ), mining area ( 0.64% ) and water area( 0.30% ). By confirming the classification results, the total accuracy is 91.61%, the Kappa coefficient is 0.8991. Overall, GF-1 Satellite data can obtain regional ecosystems quickly, and provide a better data support for regional ecological resource protection zone. For Luobei graphite mines area, farmland and residential areas within its watershed are most vulnerable to mining, the higher proportion of farmland in duck river basin. The regulatory tailings need to be strengthened in the process of graphite mining processing.

  11. Protected areas and their surrounding territory: socioecological systems in the context of ecological solidarity.

    Science.gov (United States)

    Mathevet, Raphaël; Thompson, John D; Folke, Carl

    2016-01-01

    The concept of ecological solidarity (ES) is a major feature of the 2006 law reforming national park policy in France. In the context of biodiversity conservation, the objectives of this study are to outline the historical development of ES, provide a working definition, and present a method for its implementation that combines environmental pragmatism and adaptive management. First, we highlight how ES provides a focus on the interdependencies among humans and nonhuman components of the socioecological system. In doing so, we identify ES within a framework that distinguishes ecological, socioecological, and sociopolitical interdependencies. In making such interdependencies apparent to humans who are not aware of their existence, the concept of ES promotes collective action as an alternative or complementary approach to state- or market-based approaches. By focusing on the awareness, feelings, and acknowledgement of interdependencies between actors and between humans and nonhumans, we present and discuss a learning-based approach (participatory modeling) that allows stakeholders to work together to construct cultural landscapes for present and future generations. Using two case studies, we show how an ES analysis goes beyond the ecosystem management approach to take into account how human interactions with the environment embody cultural, social, and economic values and endorse an ethically integrated science of care and responsibility. ES recognizes the diversity of these values as a practical foundation for socially engaged and accountable actions. Finally, we discuss how ES enhances academic support for a socioecological systems approach to biodiversity conservation and promotes collaboration with decision-makers and stakeholders involved in the adaptive management of protected areas and their surrounding landscapes. PMID:27039505

  12. GRB 081007 AND GRB 090424: THE SURROUNDING MEDIUM, OUTFLOWS, AND SUPERNOVAE

    Energy Technology Data Exchange (ETDEWEB)

    Jin Zhiping; Covino, Stefano; Fugazza, Dino; Melandri, Andrea; Campana, Sergio; D' Avanzo, Paolo [INAF-Osservatorio Astronomico di Brera, via Emilio Bianchi 46, I-23807 Merate (Italy); Della Valle, Massimo [INAF-Osservatorio Astronomico di Capodimonte, Salita Moiariello, 16, I-80131 Napoli (Italy); Ferrero, Patrizia [Instituto de Astrofisica de Canarias (IAC), E-38200 La Laguna, Tenerife (Spain); Malesani, Daniele; Fynbo, Johan P. U.; Hjorth, Jens [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen O (Denmark); Pian, Elena [Scuola Normale Superiore di Pisa, Piazza dei Cavalieri 7, I-56126 Pisa (Italy); Salvaterra, Ruben [INAF-IASF Milano, via E. Bassini 15, I-20133 Milano (Italy); Bersier, David [Astrophysics Research Institute, Liverpool John Moores University, Egerton Wharf, Birkenhead CH41 1LD (United Kingdom); Cano, Zach [Centre for Astrophysics and Cosmology, Science Institute, University of Iceland, Reykjavik (Iceland); Castro-Tirado, Alberto J.; Gorosabel, Javier [Instituto de Astrofisica de Andalucia (IAA-CSIC), Glorieta de la Astronomia s/n, E-18008 Granada (Spain); Gomboc, Andreja [Mathematics and Physics, University of Ljubljana, Jadranska ulica 19, 1000 Ljubljana (Slovenia); Guidorzi, Cristiano [Department of Physics, University of Ferrara, via Saragat 1, I-44122 Ferrara (Italy); Haislip, Joshua B., E-mail: jin@pmo.ac.cn [Department of Physics and Astronomy, University of North Carolina, Chapel Hill, NC 27599 (United States); and others

    2013-09-10

    We discuss the results of the analysis of multi-wavelength data for the afterglows of GRB 081007 and GRB 090424, two bursts detected by Swift. One of them, GRB 081007, also shows a spectroscopically confirmed supernova, SN 2008hw, which resembles SN 1998bw in its absorption features, while the maximum magnitude may be fainter, up to 0.7 mag, than observed in SN 1998bw. Bright optical flashes have been detected in both events, which allows us to derive solid constraints on the circumburst-matter density profile. This is particularly interesting in the case of GRB 081007, whose afterglow is found to be propagating into a constant-density medium, yielding yet another example of a gamma-ray burst (GRB) clearly associated with a massive-star progenitor which did not sculpt the surroundings with its stellar wind. There is no supernova component detected in the afterglow of GRB 090424, likely due to the brightness of the host galaxy, comparable to the Milky Way. We show that the afterglow data are consistent with the presence of both forward- and reverse-shock emission powered by relativistic outflows expanding into the interstellar medium. The absence of optical peaks due to the forward shock strongly suggests that the reverse-shock regions should be mildly magnetized. The initial Lorentz factor of outflow of GRB 081007 is estimated to be {Gamma} {approx} 200, while for GRB 090424 a lower limit of {Gamma} > 170 is derived. We also discuss the prompt emission of GRB 081007, which consists of just a single pulse. We argue that neither the external forward-shock model nor the shock-breakout model can account for the prompt emission data and suggest that the single-pulse-like prompt emission may be due to magnetic energy dissipation of a Poynting-flux-dominated outflow or to a dissipative photosphere.

  13. Radiation budget estimates over Africa and surrounding oceans: inter-annual comparisons

    Directory of Open Access Journals (Sweden)

    M. Desbois

    2007-05-01

    Full Text Available Three independent datasets of Radiation Budget at the top of the atmosphere (TOA spanning two decades are compared: the Scanner Narrow Field of View data (from ERBE, ScaRaB, and CERES instruments, 1985–2005, the ERBS Nonscanner Wide Field of View data (1985–1998 and the simulated broadband fluxes from the International Satellite Cloud Climatology Project (ISCCP-FD, 1983–2004. The analysis concerns the shortwave (SW reflected flux, the longwave (LW emitted flux and the net flux at the Top Of the Atmosphere (TOA over Africa and the surrounding oceans (45° S–45° N/60° W–60° E, a region particularly impacted by climate variability. For each month, local anomalies are computed with reference to the average over this large region, and their differences between the 2002–2005 and 1985–1989 periods are analysed. These anomalies are, for a large part, independent on the general observed trends (about 2.5 W m−2 per decade, which may be affected by possible calibration drifts. Although the regional flux anomalies can be related to calibration through the scene identification and the choice of the anisotropy correction, this effect is limited if the calibration drifts remains reasonable. Large inter-annual variations are observed locally. Over a part of the South East Atlantic (35°–10° S/10° W–10° E, including the marine low cloud area off Angola, there is a decrease of the yearly means of net flux estimated to 2.2, 3 and 6 W m−2 respectively for the Scanner, Nonscanner and ISCPP-FD data. Over a narrow strip of the Sahel Zone, the net flux increases by about 5 W m−2. We believe that these observations are real. They could be due to the impact of calibration drift but only if the drifts were significant (>4% and correlated between the datasets, which is highly improbable.

  14. Radiation budget estimates over Africa and surrounding oceans: inter-annual comparisons

    Directory of Open Access Journals (Sweden)

    A. Ben Rehouma

    2006-12-01

    Full Text Available Three independent datasets of Radiation Budget at the top of the atmosphere (TOA spanning two decades are compared: the Scanner Narrow Field of View data (from ERBE, ScaRaB, and CERES instruments, 1985–2005, the ERBS Nonscanner Wide Field of View data (1985–1998 and the simulated broadband fluxes from the International Satellite Cloud Climatology Project (ISCCP-FD, 1983–2004. The analysis concerns the shortwave (SW reflected flux, the longwave (LW emitted flux and the net flux at the Top Of the Atmosphere (TOA over Africa and the surrounding oceans (45° S–45° N/60° W–60° E, a region particularly impacted by climate variability. For each month, local anomalies are computed with reference to the average over this large region, and their differences between the 2002–2005 and 1985–1989 periods are analysed. These anomalies are relative values and are mostly independent on the absolute observed trends (about 2.5 Wm−2 per decade which may be affected by possible calibration drifts. Large inter-annual variations are observed locally. Over a part of the South East Atlantic (35°–10° S/10° W–10° E, including the marine low cloud area off Angola, there is a decrease of the yearly means of net flux estimated to 2.2, 3 and 6 Wm−2 respectively for the Scanner, Nonscanner and ISCPP-FD data. Over a narrow strip of the Sahel Zone, the net flux increases by about 5 Wm−2.

  15. Irradiation of Population in the Surrounding Area of Nuclear Power Plant Temelin

    Science.gov (United States)

    Thinova, Lenka; Kluson, Jaroslav

    2008-08-01

    In monitoring the impact of nuclear facilities operation on ecosystem, it is necessary to consider, what part of biota irradiation can be caused by an artificial source. For the estimation of an effective dose from natural sources were used measurements of dosimetric and gamma spectrometric characteristics of photon fields, (performed in the area of NPP Temelin since year 2000) and data from the Czech Republic radiometric chart, including the results from radon volume activity measurements in dwellings. For gamma spectrometric measurements in situ were selected two methodologies and for measurement were used corresponding types of equipment (Tesla NB3201 and spectrometer NaI(TI) 3"x3") at selected locations within the monitored area: i) determination of air kerma rate (through direct measurement and by calculationfrom spectrometric data); ii) measurement of photon spectra by an scintillating spectrometer. For a dose assessment from artificial sources resulting from past or present operation of NPP Temelin, were used records from all so far performed laboratory and field measurements of NPP releases, food baskets and also results of a 6 year ecosystem monitoring in the surrounding area of NPP Temelin. The ecosystem monitoring is based on studying the contamination of the following bioindicators: forest humus, Pine bark, Schreber's Moss, the Bay Bolete (mushroom) and forest berries. Each year 220 samples are collected and mass activity (Bq/kg) for eventual contaminants is determined using laboratory gamma spectroscopy. For measurements is used a coaxial HPGe detector, with samples in the geometry of "Marinelli" container. For evaluation of the laboratory results obtained is used trend analysis. The above described monitoring has been performed from the year 2000 until now (the year 2000 is pre-operational). In all measured laboratory spectra, of all analyzed samples, were not identified any non-natural radionuclides, with the exception of 137Cs, for which maesured

  16. Mechanisms of seizure propagation in 2-dimensional centre-surround recurrent networks.

    Directory of Open Access Journals (Sweden)

    David Hall

    Full Text Available Understanding how seizures spread throughout the brain is an important problem in the treatment of epilepsy, especially for implantable devices that aim to avert focal seizures before they spread to, and overwhelm, the rest of the brain. This paper presents an analysis of the speed of propagation in a computational model of seizure-like activity in a 2-dimensional recurrent network of integrate-and-fire neurons containing both excitatory and inhibitory populations and having a difference of Gaussians connectivity structure, an approximation to that observed in cerebral cortex. In the same computational model network, alternative mechanisms are explored in order to simulate the range of seizure-like activity propagation speeds (0.1-100 mm/s observed in two animal-slice-based models of epilepsy: (1 low extracellular [Formula: see text], which creates excess excitation and (2 introduction of gamma-aminobutyric acid (GABA antagonists, which reduce inhibition. Moreover, two alternative connection topologies are considered: excitation broader than inhibition, and inhibition broader than excitation. It was found that the empirically observed range of propagation velocities can be obtained for both connection topologies. For the case of the GABA antagonist model simulation, consistent with other studies, it was found that there is an effective threshold in the degree of inhibition below which waves begin to propagate. For the case of the low extracellular [Formula: see text] model simulation, it was found that activity-dependent reductions in inhibition provide a potential explanation for the emergence of slowly propagating waves. This was simulated as a depression of inhibitory synapses, but it may also be achieved by other mechanisms. This work provides a localised network understanding of the propagation of seizures in 2-dimensional centre-surround networks that can be tested empirically.

  17. Interleukin (IL)-8 immunoreactivity of injured axons and surrounding oligodendrocytes in traumatic head injury.

    Science.gov (United States)

    Hayashi, Takahito; Ago, Kazutoshi; Nakamae, Takuma; Higo, Eri; Ogata, Mamoru

    2016-06-01

    Interleukin (IL)-8 has been suggested to be a positive regulator of myelination in the central nervous system, in addition to its principal role as a chemokine for neutrophils. Immunostaining for beta-amyloid precursor protein (AβPP) is an effective tool for detecting traumatic axonal injury, although AβPP immunoreactivity can also indicate axonal injury due to hypoxic causes. In this study, we examined IL-8 and AβPP immunoreactivity in sections of corpus callosum obtained from deceased patients with blunt head injury and from equivalent control tissue. AβPP immunoreactivity was detected in injured axons, such as axonal bulbs and varicose axons, in 24 of 44 head injury cases. These AβPP immunoreactive cases had survived for more than 3h. The AβPP immunostaining pattern can be classified into two types: traumatic (Pattern 1) and non-traumatic (Pattern 2) axonal injuries, which we described previously [Hayashi et al. Int. J. Legal Med. 129 (2015) 1085-1090]. Three of 44 control cases also showed AβPP immunoreactive injured axons as Pattern 2. In contrast, IL-8 immunoreactivity was detected in 7 AβPP immunoreactive and in 2 non-AβPP immunoreactive head injury cases, but was not detected in any of the 44 control cases, including the 3 AβPP immunoreactive control cases. The IL-8 immunoreactive cases had survived from 3 to 24 days, whereas those cases who survived less than 3 days (n=29) and who survived 90 days (n=1) were not IL-8 immunoreactive. Moreover, IL-8 was detected as Pattern 1 axons only. In addition, double immunofluorescence analysis showed that IL-8 is expressed by oligodendrocytes surrounding injured axons. In conclusion, our results suggest that immunohistochemical detection of IL-8 may be useful as a complementary diagnostic marker of traumatic axonal injury.

  18. Effect of a Surrounding Liquid Environment on the Electrical Disruption of Pendant Droplets.

    Science.gov (United States)

    Mohamed, A Said; Lopez-Herrera, Jose M; Herrada, Miguel A; Modesto-Lopez, Luis B; Gañán-Calvo, Alfonso M

    2016-07-12

    The effect of a surrounding, dielectric, liquid environment on the dynamics of a suddenly electrified liquid drop is investigated both numerically and experimentally. The onset of stability of the droplet is naturally dictated by a threshold value of the applied electric field. While below that threshold the droplet retains its integrity, reaching to a new equilibrium state through damped oscillations (subcritical regime), above it electrical disruption takes place (supercritical regime). In contrast to the oscillation regime, the dynamics of the electric droplet disruption in the supercritical regime reveals a variety of modes. Depending on the operating parameters and fluid properties, a drop in the supercritical regime may result in the well-known tip streaming mode (with and without whipping instability), in droplet splitting (splitting mode), or in the development of a steep shoulder at the elongating front of the droplet that expands radially in a sort of "splashing" (splashing mode). In both splitting and splashing modes, the sizes of the progeny droplets, generated after the breakup of the mother droplet, are comparable to that of the mother droplet. Furthermore, the development in the emission process of the shoulder leading to the splashing mode is described as a parametrical bifurcation, and the parameter governing that bifurcation has been identified. Physical analysis confirms the unexpected experimental finding that the viscosity of the dynamically active environment is absent in the governing parameter. However, the appearance of the splitting mode is determined by the viscosity of the outer environment, when that viscosity overcomes a certain large value. These facts point to the highly nonlinear character of the drop fission process as a function of the droplet volume, inner and outer liquid viscosities, and applied electric field. These observations may have direct implications in systems where precise control of the droplet size is critical, such

  19. Local earthquake tomography of the Erzincan Basin and the surrounding area in Turkey

    Directory of Open Access Journals (Sweden)

    H. Gökalp

    2007-06-01

    Full Text Available In this study, selected travel time data from the aftershock series of the Erzincan earthquake (March, 1992, Ms=6.8 were inverted simultaneously for both hypocenter locations and 3D Vp and Vs structure. The general features of the 3D velocity structure of the upper crust of Erzincan Basin and the surrounding area, one of the most tectonically and seismically active regions in Turkey were investigated. The data used for this purpose were 2215 P-wave and 547 S-wave arrival times from 350 local earthquakes recorded by temporary 15 short-period seismograph stations. Thurber’s simultaneous inversion method (1983 was applied to the arrival time data to obtain a 3D velocity structure, and hypocentral locations. Both 3D heterogeneous P and S wave velocity variations down to 12 km depth were obtained. The acquired tomographic images show that the 3D velocity structure beneath the region is heterogeneous in that low velocity appears throughout the basin and at the southeastern flank, and high velocities occur at south and east of the basin. The low velocities can be related to small and large scale fractures, thus causing rocks to weaken over a long period of the active tectonic faulting process. The ophiolitic rock units mostly occurring around the basin area are the possible reason for the high velocities. The validity of 3D inversion results was tested by performing detailed resolution analysis. The test results confirm the velocity anomalies obtained from inversion. Despite the small number of inverted S-wave arrivals, the obtained 3D S velocity model has similar anomalies with lower resolution than the 3D P-wave velocity model. Better hypocenter locations were calculated using the 3D heterogeneous model obtained from tomographic inversion.

  20. Characterisation by PIXE RBS of metallic contamination of tissues surrounding a metallic prosthesis on a knee

    Science.gov (United States)

    Guibert, G.; Irigaray, J. L.; Moretto, Ph.; Sauvage, T.; Kemeny, J. L.; Cazenave, A.; Jallot, E.

    2006-09-01

    Implants used as biomaterials have to fulfill conditions of functionality, compatibility and sometimes bioactivity. There are four main families of biomaterials: metals and metal alloys, polymers, bioceramics and natural materials. Because of corrosion and friction in the human body, implants generate debris. This debris may develop toxicity, inflammation and prosthetic unsealing by osseous dissolution. Nature, size, morphology and amount of debris are the parameters influencing the tissue responses. In this paper, we characterised metallic contamination produced by knee prosthesis, composed with TiAl 6V 4 or Co-Cr-Mo alloys, into surrounding capsular tissue by depth migration, in vivo behaviour, content, size and nature of debris by PIXE (Particle Induced X-ray Emission) method associated with RBS (Rutherford Backscattering Spectroscopy). Debris distribution in the whole articulation is very heterogeneous. Debris migrates several thousand micrometers in tissues, with a characteristic decrease. Solid metallic particles of about micrometer size are found in the most polluted samples, in both alloys TiAl 6V 4 and Cr-Co-Mo. In the mean volume analysed by PIXE, the concentration mass ratios [Ti]/[V] and [Co]/[Cr] confirm the chemical stability of TiAl 6V 4 debris and show the chemical evolution of Cr-Co-Mo debris. Development of a protocol to prepare thin targets permits us to correlate PIXE and histological analysis in the same zone. The fibrous tissue (collagen fibres, fibroblasts) and macrophage cells are observed with optical microscope in polluted areas. This protocol could locate other pathologies in ppm contamination range, thanks to the great sensitivity of the PIXE method.