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Sample records for 1-wall intrabony defects

  1. Clinical concepts for regenerative therapy in intrabony defects.

    PubMed

    Cortellini, Pierpaolo; Tonetti, Maurizio S

    2015-06-01

    Evidence indicates that periodontal regeneration is an efficacious and predictable procedure for the treatment of isolated and multiple intrabony defects. Meta-analyses from systematic reviews indicate an added benefit, in terms of clinical attachment level gain, when demineralized freeze-dried bone allograft, barrier membranes and active biologic products/compounds are applied in addition to open flap debridement. On the other hand, a consistent amount of variability of the outcomes is evident among different studies and within the experimental population of each study. This variability is explained, at least in part, by different patient and defect characteristics. Patient-related factors include smoking habit, compliance with home oral hygiene and residual inflammation after cause-related therapy. Defect-associated factors include defect depth and radiographic angle, the number of residual bony walls, pocket depth and the degree of hypermobility. In addition, surgical-related variables, such as surgical skill, clinical experience and knowledge, and application of the different regenerative materials, have a significant impact on clinical outcomes. This paper presents a strategy to optimize the clinical outcomes of periodontal regeneration. The surgical design of the flap, the use of different regenerative materials and the application of appropriate passive sutures are discussed in this review along with the scientific foundations. PMID:25867990

  2. Efficacy of Connective Tissue with and without Periosteum in Regeneration of Intrabony Defects

    PubMed Central

    Esfahanian, Vahid; Golestaneh, Hedayatollah; Moghaddas, Omid; Ghafari, Mohammad Reza

    2014-01-01

    Background and aims. Connective tissue grafts with and without periosteum is used in regenerative treatments of bone and has demonstrated successful outcomes in previous investigations. The aim of present study was to evaluate the effectiveness of connective tissue graft with and without periosteum in regeneration of intrabony defects. Materials and methods. In this single-blind randomized split-mouth clinical trial, 15 pairs of intrabony defects in 15 patients with moderate to advanced periodontitis were treated by periosteal connective tissue graft + ABBM (test group) or non-periosteal connective tissue graft + ABBM (control group). Probing pocket depth, clinical attachment level, free gingival margin position, bone crestal position, crest defect depth and defect depth to stent were measured at baseline and after six months by surgical re-entry. Data was analyzed by Student’s t-test and paired t-tests (α=0.05). Results. Changes in clinical parameters after 6 months in the test and control groups were as follows: mean of PPD reduction: 3.1±0.6 (P<0.0001); 2.5±1.0 mm (P<0.0001), CAL gain: 2.3±0.9 (P<0.0001); 2.2±1.0 mm (P<0.0001), bone fill: 2.2±0.7 mm (P<0.0001); 2.2±0.7 mm (P<0.0001), respectively. No significant differences in the position of free gingival margin were observed during 6 months compared to baseline in both groups. Conclusion. Combinations of periosteal connective tissue graft + ABBM and non-periosteal connective tissue graft + ABBM were similarly effective in treating intrabony defects without any favor for any group. Connective tissue and perio-steum can be equally effective in regeneration of intrabony defects. PMID:25587379

  3. Biomaterials for promoting periodontal regeneration in human intrabony defects: a systematic review.

    PubMed

    Sculean, Anton; Nikolidakis, Dimitris; Nikou, George; Ivanovic, Aleksandar; Chapple, Iain L C; Stavropoulos, Andreas

    2015-06-01

    Intrabony periodontal defects are a frequent complication of periodontitis and, if left untreated, may negatively affect long-term tooth prognosis. The optimal outcome of treatment in intrabony defects is considered to be the absence of bleeding on probing, the presence of shallow pockets associated with periodontal regeneration (i.e. formation of new root cementum with functionally orientated inserting periodontal ligament fibers connected to new alveolar bone) and no soft-tissue recession. A plethora of different surgical techniques, often including implantation of various types of bone graft and/or bone substitutes, root surface demineralization, guided tissue regeneration, growth and differentiation factors, enamel matrix proteins or various combinations thereof, have been employed to achieve periodontal regeneration. Despite positive observations in animal models and successful outcomes reported for many of the available regenerative techniques and materials in patients, including histologic reports, robust information on the degree to which reported clinical improvements reflect true periodontal regeneration does not exist. Thus, the aim of this review was to summarize, in a systematic manner, the available histologic evidence on the effect of reconstructive periodontal surgery using various types of biomaterials to enhance periodontal wound healing/regeneration in human intrabony defects. In addition, the inherent problems associated with performing human histologic studies and in interpreting the results, as well as certain ethical considerations, are discussed. The results of the present systematic review indicate that periodontal regeneration in human intrabony defects can be achieved to a variable extent using a range of methods and materials. Periodontal regeneration has been observed following the use of a variety of bone grafts and substitutes, guided tissue regeneration, biological factors and combinations thereof. Combination approaches appear to

  4. Use of Fisiograft in Intrabony Defects- A Clinical and Radiological Study

    PubMed Central

    Pandey, Ruchi; Madhumala, R.; Saranyan, R.; Sreekanth, P.

    2013-01-01

    Aim: To evaluate the efficacy of Polylactic Acid/Polygycolic Acid (PLA/PGA -Fisiograft®) with Open Flap Debridement (OFD) and OFD alone in the treatment of intrabony defects over a period of 9 months. Material and Methods: Twenty Nine systemically healthy subjects with total of 30 defects were included in the present, randomized, controlled and two arm parallel study. Tests were treated with OFD along with Fisiograft® and controls with OFD alone. Results: On intra-group comparison, clinical parameters at 6 and 9 months showed statistically significant results. On comparing between the two groups, the reduction in Defect Specific Bleeding Score (DSBS), Defect Specific Plaque Score (DSPS), Probing Depth (PD) and gain in Clinical Attachment Level (CAL) revealed no statistical significances other than Recession Depth (REC) which was more in controls. The mean radiographic parameters at 9 months post-operatively in both the groups were statistically significant. However, the inter-group comparison revealed no statistically significant values. Conclusions: The overall results at the end study proved that the adjunctive use of Fisiograft® was not beneficial when compared with OFD alone. Clinical Significance: Synthetic bone replacement graft materials are commonly used for periodontal regeneration. The present study was conducted by using PLA/PGA reveals no additional benefit over OFD alone in treatment of intrabony defects. PMID:24298530

  5. Systemic Teriparatide Administration Promotes Osseous Regeneration of an Intrabony Defect: A Case Report

    PubMed Central

    Bashutski, Jill D.; Kinney, Janet S.; Benavides, Erika; Maitra, Samopriyo; Braun, Thomas M.; Giannobile, William V.; McCauley, Laurie K.; Eber, Robert M.

    2015-01-01

    Introduction Teriparatide comprises the first 34 amino acids of parathyroid hormone and is a systemic anabolic agent that is Food and Drug Administration approved for the treatment of osteoporosis but not for periodontitis. To our knowledge, this is the first clinical case report to document the treatment of a patient with severe periodontitis using an open-flap debridement procedure in conjunction with teriparatide. Case Presentation A 45-year-old female patient was diagnosed with severe chronic periodontitis, including the presence of an intrabony defect on tooth #6. She received open-flap debridement surgery in conjunction with daily systemic administration of 20 µg teriparatide, oral vitamin D, and calcium supplements for 6 weeks. Radiographic, clinical, gingival crevicular fluid (pyridinoline cross-linked carboxy-terminal propeptide of type I procollagen, procollagen type 1 N-propeptide, and osteocalcin), and serum parameters (parathyroid hormone, bone alkaline phosphatase, calcium, and 25-hydroxyvitamin D) were assessed. Treatment outcomes were evaluated over 4 years, with successful radiographic and clinical results throughout the follow-up period. Conclusion Teriparatide administration in conjunction with traditional open-flap debridement surgery offers potential for the treatment of severe intrabony defects resulting from chronic periodontitis. PMID:26525954

  6. Treatment of intrabony periodontal defects with enamel matrix derivative: a literature review.

    PubMed

    Kalpidis, Christos D R; Ruben, Morris P

    2002-11-01

    The enamel matrix derivative (EMD) has been recently introduced in the periodontal field to overcome short-comings associated with currently available regenerative techniques. Information accumulated over the past years with application of EMD guided regeneration (EGR) in intrabony periodontal defects allowed a thorough evidence-based retrospective analysis. Clinical data from EMD controlled studies were pooled for meta-analysis and weighted according to the number of treated defects. Clinical attachment gain amounted to 3.2 +/- 0.9 mm (33% of the original attachment level) and probing reduction averaged 4.0 +/- 0.9 mm (50% of the baseline probing depth) for a total of 317 lesions with a mean baseline depth of 5.4 +/- 0.8 mm. Improvements in clinical parameters achieved with EMD were statistically significant in reference to preoperative measurements. However, despite the overall efficacy of EGR therapy, a significant variation in clinical outcomes was observed. Similar therapeutic results were reported in studies where EGR was compared directly to guided tissue regeneration. However, the controlled clinical trials did not have adequate statistical power to firmly support superiority or equivalency between the 2 regenerative therapies. The statistical superiority of EGR over treatment with open flap debridement has been established. Preliminary histologic investigations with surgically created defects and experimental periodontal lesions demonstrated the ability of EGR to induce formation of acellular cementum and promote significant anaplasis of the supporting periodontal tissues. The potential of EMD to encourage periodontal regeneration was also confirmed in human intrabony defects. However, recent human histologic studies have questioned both the consistency of the histologic outcomes and the ability of EGR to predictably stimulate formation of acellular cementum. Identifying clinical modifying parameters and understanding cellular interactions are apparently

  7. Treatment of intrabony defects with anorganic bone matrix/p-15 or guided tissue regeneration in patients with aggressive periodontitis.

    PubMed

    Queiroz, Adriana C; Nóbrega, Priscila Brasil da; Oliveira, Fabíola S; Novaes, Arthur B; Taba, Mário; Palioto, Daniela B; Grisi, Márcio F M; Souza, Sergio L S

    2013-01-01

    Intrabony periodontal defects present a particular treatment problem, especially in patients with generalized aggressive periodontitis (G-AgP). Regenerative procedures have been indicated for this clinical situation. The aim of this study was to compare treatment outcomes of intrabony periodontal defects with either anorganic bone matrix/cell binding peptide (ABM/P-15) or guided tissue regeneration (GTR) in patients with G-AgP. Fifteen patients, with two intrabony defects ≥3 mm deep, were selected. Patients were randomly allocated to be treated with ABM/P-15 or GTR. At baseline and at 3 and 6 months after surgery, clinical and radiographic parameters and IL-1β and IL-6 gingival fluid concentrations were recorded. There was a significant probing pocket depth reduction (p<0.001) for both groups (2.27 ± 0.96 mm for ABM/P-15 group and 2.57 ± 1.06 mm for GTR group). Clinical attachment level gain (1.87 ± 0.94 mm for ABM/P-15 group and 2.09 ± 0.88 mm for GTR group) was also observed. There were no statistically significant differences in clinical parameters between the groups. The radiographic bone fill was more expressive in ABM/P-15 group (2.49 mm) than in GTR group (0.73 mm). In subtraction radiographs, the areas representing gain in density were 93.16% of the baseline defect for ABM/P-15 group versus 62.03% in GRT group. There were no statistically significant differences in inter-group and intra-group comparisons with regards to IL-1β and IL-6 quantification. Treatment of intrabony periodontal defects in patients with G-AgP with ABM/P-15 and GTR improved significantly the clinical outcomes. The use of ABM/P-15 promoted a better radiographic bone fill. PMID:23969907

  8. Clinical and radiographic evaluation of periodontal intrabony defects by open flap surgery alone or in combination with Biocollagen® membrane: A randomized clinical trial

    PubMed Central

    Elkhatat, Essam I.; Elkhatat, Amr E.; Azzeghaiby, Saleh N.; Tarakji, Bassel; Beshr, Khaled; Mossa, Hossam

    2015-01-01

    Background: Guided tissue regeneration (GTR) is often incorporated in regenerative periodontal surgical procedures. However, the actual benefits of adding GTR to such a procedure remain undocumented. The purpose of this randomized controlled trial was to investigate the contribution of GTR to the outcomes of open flap debridement (OFD) in the treatment of intrabony defects. Materials and Methods: A total of 16 patients of both sexes satisfying the criteria of chronic periodontitis and each of whom displayed one intrabony defect were randomly assigned to two groups, i.e. either treated with open flap surgery and GTR (group 1) or with open flap surgery alone (group 2), in this parallel-arm study. The soft tissue and hard tissue measurements, including probing pocket depth (PD), clinical attachment level (CAL), and bone mineral density were recorded at baseline and 3,6 and 12 months after surgery. The differences with a P < 0.05 were considered significant. Results: Results showed that the membrane group showed significant difference when compared with open flap surgery alone, in relation to the degree of periodontal pocket, clinical attachment loss, and bone density. Conclusion: The findings of this study suggest that biocollagen membrane could be considered as an option in the treatment of intrabony defects. Biocollagen membrane alone gives favorable clinical results in the treatment of intrabony defects. Open flap debridement resulted in acceptable clinical results in the treatment of intrabony defects. PMID:26236678

  9. Evaluation of intrabony defects treated with platelet-rich fibrin or autogenous bone graft: A comparative analysis

    PubMed Central

    Mathur, Ashish; Bains, Vivek Kumar; Gupta, Vivek; Jhingran, Rajesh; Singh, G. P.

    2015-01-01

    Objective: The primary objective of this study was to compare clinically and radiographically the efficacy of autologous platelet rich fibrin (PRF) and autogenous bone graft (ABG) obtained using bone scrapper in the treatment of intrabony periodontal defects. Materials and Methods: Thirty-eight intrabony defects (IBDs) were treated with either open flap debridement (OFD) with PRF or OFD with ABG. Clinical parameters were recorded at baseline and 6 months postoperatively. The defect-fill and defect resolution at baseline and 6 months were calculated radiographically (intraoral periapical radiographs [IOPA] and orthopantomogram [OPG]). Results: Significant probing pocket depth (PPD) reduction, clinical attachment level (CAL) gain, defect fill and defect resolution at both PRF and ABG treated sites with OFD was observed. However, inter-group comparison was non-significant (P > 0.05). The bivariate correlation results revealed that any of the two radiographic techniques (IOPA and OPG) can be used for analysis of the regenerative therapy in IBDs. Conclusion: The use of either PRF or ABG were effective in the treatment of three wall IBDs with an uneventful healing of the sites. PMID:25713492

  10. Minimally Invasive Surgery Combined with Regenerative Biomaterials in Treating Intra-Bony Defects: A Meta-Analysis

    PubMed Central

    Zhang, Yuanyuan; Li, Wenyang; Song, Jinlin

    2016-01-01

    Background With the popularity of minimally invasive surgery (MIS) in periodontics, numerous publications have evaluated the benefits of MIS with or without various regenerative biomaterials in the treatment of periodontal intra-bony defects. However, it is unclear if it is necessary to use biomaterials in MIS. Thus, we conducted a meta-analysis of randomized clinical trials in patients with intra-bony defects to compare the clinical outcomes of MIS with regenerative biomaterials for MIS alone. Methods The authors retrieved English publications on relevant studies from Cochrane CENTRAL, PubMed, Medline, Embase, Clinical Evidence, and ClinicalTrails.gov (up to June 30, 2015). The main clinical outcomes were the reduction of probing pocket depths (PPDs), gain of clinical attachment level (CAL), recession of gingival margin (REC) and radiographic bone fill. Review Manager 5.2 (Cochrane Collaboration, Oxford, England) was used to calculate the heterogeneity and mean differences of the main clinical outcomes. Results In total, 464 studies in the literature were identified but only four were ultimately feasible. The results showed no significant difference regarding CAL gain (P = 0.32) and PPD reduction (P = 0.40) as well as REC increase (P = 0.81) and radiographic bone fill (P = 0.64) between the MIS plus biomaterials group and the MIS alone group. Conclusions The meta-analysis suggested no significant difference in treatment of intra-bony defects between the MIS plus biomaterials group and the MIS alone group, indicating that it is important to take costs and benefits into consideration when a decision is made about a therapeutic approach. There needs to be an in-depth exploration of the induction of intrinsic tissue healing of MIS without biomaterials to achieve optimal outcomes. PMID:26785405

  11. Comparative study of two collagen membranes for guided tissue regeneration therapy in periodontal intrabony defects: a randomized clinical trial

    PubMed Central

    2014-01-01

    Purpose The purpose of this study was to assess and compare the clinical and radiographic outcomes of guided tissue regeneration therapy for human periodontal intrabony defects using two different collagen membranes: a porous nonchemical cross-linking collagen membrane (NC) and a bilayer collagen membrane (BC). Methods Thirty subjects were randomly assigned and divided into the following 3 groups: a test group (NC+BM), in which a NC was used with xenograft bone mineral (BM), a positive control group (BC+BM), in which a BC was used with xenograft BM, and a negative control group (BM), in which only xenograft BM was used. The following clinical measurements were taken at baseline and 3 months after surgery: plaque index, gingival index, probing pocket depth, gingival recession, and clinical attachment level. Radiographic analysis was performed at baseline, 1 week and 3 months after surgery. Results Membrane exposure was not observed in any cases. Significant probing depth reduction, attachment-level gain and bone fill were observed for both test and control groups compared to baseline at 3 months after surgery (P<0.05). However, there were no statistically significant differences in clinical improvement and radiographic bone fill between treatment protocols (P>0.05). Conclusions Within the limitations of this study, the results suggest that both NC and BC were comparable in terms of clinical and radiographic outcomes for the treatment of periodontal intrabony defects in human subjects. Graphical Abstract PMID:25177521

  12. Evaluation of 660 nm LED light irradiation on the strategies for treating experimental periodontal intrabony defects.

    PubMed

    Tao, Chih-Yun; Lee, Ning; Chang, Hao-Chieh; Yang, Connie; Yu, Xin-Hong; Chang, Po-Chun

    2016-08-01

    This study aims to investigate the therapeutic value of 660 nm light-emitting diode (LED) light irradiation on the strategies for treating experimental periodontal intrabony defects in vivo. Large-sized periodontal intrabony defects were created bilaterally on the mesial aspect of the maxillary second molars of 48 Sprague-Dawley rats, and the rats were equally divided into four treatment groups with primary wound intention (n = 6/treatment/time point), including open flap debridement alone (OD), barrier membrane alone (MB), xenograft alone (BG), and xenograft plus barrier membrane (MG). Each group received daily 0 or 10 J/cm(2) LED light irradiation. The animals were sacrificed after 1 or 4 weeks. The treatment outcome was evaluated by gross observation of wound dehiscence and healing, micro-CT imaging for osteogenesis, and histological assessments for inflammatory cell infiltration and periodontal reattachment. With LED light irradiation, the extent of wound dehiscence was reduced, wound closure was accelerated, epithelial downgrowth was prevented, inflammation was reduced, and periodontal reattachment was promoted in all treatment strategies. Significant reduction of inflammation with LED light irradiation was noted at 1 week in the groups BG and MG (p < 0.05). Osteogenesis was significantly promoted only in the group OD at both time points (p < 0.05). Our study showed that 660 nm LED light accelerates mucoperiosteal flap healing and periodontal reattachment. However, the enhancement of osteogenesis appeared to be limited while simultaneously treating with a barrier membrane or xenograft. PMID:27184157

  13. Evaluation of efficacy of enamel matrix derivative in the treatment of intrabony defects: a 24-month multicenter study.

    PubMed

    Francetti, Luca; Trombelli, Leonardo; Lombardo, Giorgio; Guida, Luigi; Cafiero, Carlo; Roccuzzo, Mario; Carusi, Giorgio; Del Fabbro, Massimo

    2005-10-01

    The aim of this prospective multicenter controlled clinical study was to evaluate the efficacy of Emdogain (Biora), an enamel matrix derivative (EMD), when combined with surgical treatment of periodontal angular defects, as compared to surgery alone, for up to 24 months of follow-up. The study was performed at six Italian universities and 11 private practices. Patients with one-, two-, or three-wall angular defects were enrolled if intrabony defect depth (IBD) was 4 mm or more and probing pocket depth (PPD) was at least 6 mm. They were randomly allocated to either test or control groups. The test group was treated by the simplified papilla preservation (SPP) flap plus Emdogain after root conditioning with ethylenediaminetetraacetic acid. The control group was treated by SPP alone. Plaque Index, Gingival Index, PPD, and periodontal attachment level (PAL) at surgical sites were assessed at the presurgical examination (baseline). IBD was measured intraoperatively after debridement. IBD was also evaluated with a computer-aided technique, from periapical radiographs. Plaque Index, Gingival Index, PPD, PAL, and IBD were assessed at 12 and 24 months postsurgery. Data were further divided in two subgroups according to baseline IBD (6 mm or less and more than 6 mm). The differences between each follow-up and baseline, and between groups at each follow-up, for the above parameters were evaluated by standard statistical methods. One hundred fifty-three patients were recruited, accounting for 195 intrabony defects: 83 patients (108 defects) and 70 patients (87 defects) were allocated to the test and control groups, respectively. All parameters were improved at both 12 and 24 months, compared to baseline in both groups. In the test group, IBD, PPD, and PAL at 12 months were significantly better than these parameters in the control group. The test subgroup with IBD of more than 6 mm at baseline displayed a better outcome when compared to the 6 mm or less IBD subgroup. No

  14. Torus mandibularis bone chips combined with platelet rich plasma gel for treatment of intrabony osseous defects: clinical and radiographic evaluation.

    PubMed

    Hassan, K S; Alagl, A S; Abdel-Hady, A

    2012-12-01

    The use of platelet rich plasma (PRP) gel in combination with torus mandibularis offers a potentially useful treatment for periodontal osseous defects. Whether this combination enhances the outcome of periodontal regenerative therapy is not known. This study compared the effectiveness of torus mandibularis bone chips alone and when combined with autogenous PRP gel in treating periodontal osseous defects. 24 sites from 12 patients were selected using a split mouth design and determined by a double-blind, randomized, controlled clinical trial. Both sites received a full-thickness mucoperiosteal flap; one intrabony defect was filled with torus mandibularis bone chips alone and the other with torus mandibularis bone chips mixed with PRP gel. There was a 57% gain in the clinical attachment level and 60% reduction in the probing depth for torus mandibularis alone compared to 72% and 68% for sites treated with torus mandibularis and PRP gel (p ≤ 0.01). There was a statistically significant difference in the bone dentistry and the marginal bone loss at sites with PRP gel compared to those without gel (p ≤ 0.01). The use of mandibular tori as autogenous bone graft combined with PRP gel showed a significant improvement in the clinical outcome of periodontal therapy than mandibular tori alone. PMID:22483445

  15. Treatment of Intrabony Defects by DFDBA Alone or in Combination with PRP: A Split-Mouth Randomized Clinical and Three-Dimensional Radiographic Trial

    PubMed Central

    Shahidi, Shoaleh; Basri, Amar; Houshyar, Maral

    2015-01-01

    Objectives: The efficacy of adding platelet-rich plasma (PRP) to demineralized freeze-dried bone allograft (DFDBA) in order to improve the clinical and radiographic results obtained in treatment of deep periodontal intrabony defects has yet to be fully elucidated. Materials and Methods: This double blind, split-mouth randomized controlled clinical trial was conducted on 12 patients with two comparable bilateral intrabony defects. Each pair of defects was randomly treated with DFDBA+PRP (test) or DFDBA alone (control). Clinical attachment level (CAL), intrabony defect depth (IDD), distance from the stent to the alveolar crest and pocket depth (PD) as well as radiographic parameters including the radiographic defect depth, width and angulation were measured at baseline and six months post-operatively. The paired t-test was used to compare the pre and post-treatment values and the unpaired t-test compared the test and control groups. Results: The mean reductions in PD and CAL were 4.5 ±1.3 mm and 3.6±1.6 mm in sites treated with DFDBA+ PRP, respectively (P<0.01); these reductions were 4.1±1.4 mm and 3.5±1.3 mm, respectively in DFDBA group (P<0.01). Radiographic evaluation revealed 2.5±1.1 mm reduction in the radiographic defect depth in the test and 2.1±1.2 mm in the control sites. The defect angulation increased at both sites. Statistically, there were no significant differences between the two treatment modalities (P<0.01). Conclusion: This study showed that both treatments resulted in significant PD reduction, CAL gain and IDD reduction. Also, PRP failed to enhance the results obtained by DFDBA. PMID:27252760

  16. Four-year results following treatment of intrabony periodontal defects with an enamel matrix derivative alone or combined with a biphasic calcium phosphate.

    PubMed

    Pietruska, Malgorzata; Pietruski, Jan; Nagy, Katalin; Brecx, Michel; Arweiler, Nicole Birgit; Sculean, Anton

    2012-08-01

    The aim of this study was to evaluate the 4-year clinical outcomes following regenerative surgery in intrabony defects with either EMD + BCP or EMD. Twenty-four patients with advanced chronic periodontitis, displaying one-, two-, or three-walled intrabony defect with a probing depth of at least 6 mm, were randomly treated with either EMD + BCP (test) or EMD alone (control). The following clinical parameters were evaluated at baseline, at 1 year and at 4 years after regenerative surgery: plaque index, gingival index, bleeding on probing, probing depth, gingival recession, and clinical attachment level (CAL). The primary outcome variable was CAL. No differences in any of the investigated parameters were observed at baseline between the two groups. The test group demonstrated a mean CAL change from from 10.8 ± 1.6 mm to 7.4 ± 1.6 mm (p < 0.001) and to 7.6 ± 1.7 mm (p < 0.001) at 1 and 4 years, respectively. In the control group, mean CAL changed from 10.4 ± 1.3 at baseline to 6.9 ± 1.0 mm (p < 0.001) at 1 year and 7.2 ± 1.2 mm (p < 0.001) at 4 years. At 4 years, two defects in the test group and three defects in the control group have lost 1 mm of the CAL gained at 1 year. Compared to baseline, at 4 years, a CAL gain of ≥3 mm was measured in 67% of the defects (i.e., in 8 out of 12) in the test group and in 75% of the defects (i.e., in 9 out of 12) in the control group. There were no statistically significant differences in any of the investigated parameters at 1 and at 4 years between the two groups. Within their limits, the present results indicate that: (a) the clinical improvements obtained with both treatments can be maintained over a period of 4 years, and (b) in two- and three-walled intrabony defects, the addition of BCP did not additionally improve the outcomes obtained with EMD alone. In two- and three-walled intrabony defects, the combination of EMD + BCP did not show any advantage over the use of EMD alone. PMID:21881869

  17. Comparative Evaluation of Platelet-Rich Fibrin Biomaterial and Open Flap Debridement in the Treatment of Two and Three Wall Intrabony Defects

    PubMed Central

    Ajwani, Himanshu; Shetty, Sharath; Gopalakrishnan, Dharmarajan; Kathariya, Rahul; Kulloli, Anita; Dolas, R S; Pradeep, A R

    2015-01-01

    Background: Platelet-rich concentrates are the most widely used regenerative biomaterials. Stimulation and acceleration of soft and hard tissue healing are due to local and continuous delivery of growth factors and proteins, mimicking the needs of the physiological wound healing and reparative tissue processes. This article aims to evaluate the clinical efficacy of open flap debridement (OFD) with or without platelet-rich fibrin (PRF) in the treatment of intrabony defects. Materials and Methods: Twenty subjects with forty intrabony defects were treated with either autologous PRF with open-flap debridement (test, n = 20) or open-flap debridement alone (control, n = 20). Soft tissue parameters included: Plaque index, sulcus bleeding index, probing depth, relative attachment level and gingival marginal level (GML). The hard tissue parameters included-distances from: Cement enamel junction to the base of the defect (CEJ-BOD): Alveolar crest to the base of the defect (AC-BOD): And CEJ to AC. The parameters were recorded at baseline and at 9 months postoperatively calculated using standardized radiographs by image-analysis software. Results: Statistically significant (0.005*) intragroup improvements were seen with all the hard and soft parameters in both test and control groups, except for GML. Statistically significant improvements were seen with the mean defect fill (CEJ-BOD and AC-BOD) (P = 0.003*) when intergroup comparisons were made. Conclusions: Adjunctive use of PRF with OFD significantly improves defect fill when compared to OFD alone. PRF has consistently been showing regenerative potential; it is simple, easy and inexpensive biomaterial compared with bone grafts. PMID:25954068

  18. Three-dimensional micro-computed tomographic evaluation of periodontal regeneration: a human report of intrabony defects treated with Bio-Oss collagen.

    PubMed

    Nevins, Marc L; Camelo, Marcelo; Rebaudi, Alberto; Lynch, Samuel E; Nevins, Myron

    2005-08-01

    This study utilized three-dimensional micro-computed tomography (micro-CT) to evaluate the regenerative response to Bio-Oss Collagen when used alone or in combination with a Bio-Gide bilayer collagen membrane for the treatment of four intrabony defects (5 to 7 mm) around single-rooted teeth. The micro-CT observations are compared to the clinical, radiographic, and histologic results, which have been previously reported. After reflecting a full-thickness flap, thorough degranulation and root planing were accomplished. Bio-Oss Collagen was then used to fill the defects, and in two cases a Bio-Gide membrane was placed over the filled defect. Radiographs, clinical probing depths, and attachment levels were obtained before treatment and immediately preceding en bloc resection of teeth and surrounding tissues 9 months later. A mean pocket depth reduction of 5.75 mm and mean clinical attachment level gain of 5.25 mm were recorded. The histologic evaluation demonstrated the formation of a complete new attachment apparatus with new cementum, periodontal ligament, and alveolar bone at the level of and coronal to the calculus reference notch. Micro-CT evaluation confirmed the histologic results and demonstrated the absence of ankylosis or root resorption for all specimens. This human histologic study demonstrated that Bio-Oss Collagen has the capacity to facilitate regeneration of the periodontal attachment apparatus when placed in intrabony defects. Micro-CT observations confirmed the histologic results and enhanced the three-dimensional understanding of periodontal wound healing. The results indicate that micro-CT may be useful for three-dimensional evaluation of periodontal regenerative procedures. PMID:16089044

  19. Labial-cervical-vertical groove: A silent killer-Treatment of an intrabony defect due to it with platelet rich fibrin.

    PubMed

    Shah, Mishal P; Gujjari, Sheela K; Shah, Kinnari M

    2014-01-01

    A 47-year-old male patient reported to the Department of Periodontology, with a chief complaint of pus discharge from maxillary left central incisors with dull intermittent pain. On clinical examination, a localized gingival inflammation was present with soft edematous tissue with the accumulation of plaque and calculus with #11 and #21. Periodontal examination depicts a periodontal pocket depth of 11 mm on mesial aspect and 8 mm on midbuccal aspect of #21 with no mobility. On radiographic examination, a tear-shaped radiolucency was present with localized bone loss in #21. On careful examination, labial-cervical-vertical groove (LCVG) was found on #21 which was extending into gingival sulcus. This article reports the effectiveness of platelet rich fibrin for the treatment of intrabony defect associated with labial-cervical-vertical groove of #21. PMID:24744556

  20. Nano-crystalline hydroxyapatite bone graft combined with bioresorbable collagen membrane in the treatment of periodontal intrabony defects: A randomized controlled clinical trial

    PubMed Central

    Singh, Vijendra P.; Nayak, Dilip G.; Uppoor, Ashita S.; Shah, Dipen

    2012-01-01

    Aim: To evaluate the clinical outcome of nanocrystalline hydroxyapatite (NcHA) bonegraft (Sybograf®) in combination with collagen membrane (PerioCol®) compared with open flap debridement (OFD) only in the treatment of intrabony periodontal defects. Materials and Methods: Eighteen intrabony defects in 16 systemically healthy patients aged between 25-65 years, were randomly assigned to test and control groups. The Plaque index, gingival index, probing pocket depth (PPD), clinical attachment level (CAL), and gingival recession were recorded at baseline, and were reevaluated at 6 months. In addition to this, radiographic bone fill was assessed using digital software. At the test site NcHA bone graft and collagen membrane was placed, whereas at the control site only, OFD was done. Recall appointments were made at 7th day, 1st month, 3rd month, and 6th month. Results: The data were subjected to statistical analysis using the Mann-Whitney ‘U’ Test and Wilcoxon signed rank sum test. In the control group, the mean reduction of PPD was 3.22±1.09 mm and CAL gain was 2.78±1.09 mm. In the test group, the mean PPD reduction of 4.33±0.5 mm and mean gain in CAL was 3.78±0.66 mm at 6 months. The mean increase in gingival recession was 0.55±0.72 mm in test and 0.44±0.52 mm in control group. Conclusion: The NcHA bone graft in combination with collagen membrane demonstrated better clinical outcomes compared with OFD alone. PMID:23493628

  1. A Clinical Comparison of Cenobone (A Decalcified Freeze-dried Bone Allograft) with Autogenous Bone Graft in the Treatment of Two- and Three-wall Intrabony Periodontal Defects: A Human Study with Six-month Reentry

    PubMed Central

    Abolfazli, Nader; Saleh Saber, Fariba; Lafzi, Ardeshir; Eskandari, Amir; Mehrasbi, Sarah

    2008-01-01

    Background and aims Complete and predictable regeneration of tissue lost as a result of infection or trauma is the ultimate goal of periodontal therapy. Various graft materials have been successfully used in the treatment of intrabony defects. The purpose of this study was to evaluate the use of a decalcified freeze-dried bone allograft (Cerabone) with the autogenous bone graft as a gold standard in the treatment of human two- or three-wall intrabony periodontal defects. Materials and methods This split-mouth study was done on 10 pairs of matched two- or three-wall intrabony periodontal defects with 5 mm or more probing depth and 3 mm or more depth of intrabony component following phase I therapy. In the control sites autogenous bone graft and in the test sites decalcified freeze-dried bone allograft were used. Results At baseline, no significant differences were found in terms of oral hygiene and defect charac-teristics. At six months, analysis showed a significant improvement in soft and hard tissue parameters for both treatment groups as compared to preoperative measurements. There were no statistical differ-ences in clinically-measured parameters between treatment groups after 6 months except for crestal resorption that increased significantly in control group (P = 0.25). Defect resolution and bone fill in the test and control groups were 2.5 ± 0.46 mm versus 2.7 ± 0.73 mm and 2 ± 0.62 mm versus 2.20 ± 0.52 mm, respectively. Conclusion The results of this study demonstrated that both graft materials improved clinical parameters. The comparison of the two treatment groups did not show any significant differences in clinical parameters after six months. However, because of the limited amount of intra-oral donor bone, it is preferable to use decalcified freeze-dried bone allograft. PMID:23285322

  2. Clinical and radiographic evaluation of Nano-crystalline hydroxyapatite bone graft (Sybograf®) in combination with bioresorbable collagen membrane (Periocol®) in periodontal intrabony defects

    PubMed Central

    Singh, Vijendra P.; Nayak, Dilip G.; Uppoor, Ashita S.; Shah, Dipen

    2012-01-01

    Background: Nanosized ceramics may represent a promising class of bone graft substitutes due to their improved osseointegrative properties. Nanocrystalline Hydroxyapatite (NcHA) bind to bone and stimulate bone healing by stimulation of osteoblast activity. The present study aims to explore the clinical and radiographical outcome of NcHA bonegraft (Sybograf®) with collagen membrane (Periocol®), in comparison with open flap debridement (OFD), in the treatment of intrabony periodontal defects. Materials and Methods: A parallel-group, randomized, controlled clinical trial was designed to conduct the study. Eighteen intrabony defects in 14 systemically healthy patients aged between 25 to 65 years were randomly assigned to test and control group. The plaque index, gingival index, probing pocket depth (PPD), clinical attachment level (CAL), and gingival recession (REC) were recorded at baseline, and were reevaluated at 6 months. In addition to this, radiographic bone fill was assessed using digital software. At the test site, NcHA bone graft and collagen membrane was placed, whereas at the control site, only OFD was done. Recall appointments were made at 7 days, 30 days, and then at 3 months and 6 months. Results: The data were subjected to statistical analysis using the Mann-Whitney ‘U’ Test and Wilcoxon signed rank sum test. In the control group, the mean reduction of PPD was 3.22±1.09 mm (P=0.007) and CAL gain was 2.77±1.09 mm (P=0.007). In the test group, the mean PPD reduction of 4.33±0.5 mm (P=0.006) and mean gain in CAL was 3.77±0.66 mm (P=0.006) at 6 months. The mean increase in REC was 0.55±0.72 mm (P=0.025) in test, and 0.44±0.52 mm (P=0.046) in control group. The mean gain in radiographic defect fill was 2.07±0.67 mm (P=0.008) in test and 0.91±0.21 mm (P=0.007) in control group. Conclusion: The nanocrystalline hydroxyapatite bone graft in combination with collagen membrane demonstrated clinical advantages beyond that achieved by OFD alone. PMID

  3. A comparative evaluation of freeze dried bone allograft and decalcified freeze dried bone allograft in the treatment of intrabony defects: A clinical and radiographic study

    PubMed Central

    Gothi, Rajat; Bansal, Mansi; Kaushik, Mayur; Khattak, Braham Prakash; Sood, Nikhil; Taneja, Vishal

    2015-01-01

    Background: Ideal graft material for regenerative procedures is autogenous bone graft but the major disadvantage with this graft is the need for a secondary surgical site to procure donor material and the frequent lack of intraoral donor site to obtain sufficient quantities of autogenous bone for multiple or deep osseous defects. Hence, to overcome these disadvantages, bone allografts were developed as an alternative source of graft material. Materials and Methods: In 10 patients with chronic periodontitis, 20 bilateral infrabony defects were treated with freeze dried bone allograft (FDBA-Group A) and decalcified freeze dried bone allograft (DFDBA-Group B). Clinical and radiographic parameters were assessed preoperatively and at 3 months and 6 months postoperatively. Data thus obtained was subjected to statistical analysis. Results: Significant improvement in the reduction in probing depth and relative attachment level (RAL) from the baseline to 3 months to baseline to 6 months in group A and group B, which was statistically significant but no statistically significant reduction was seen between 3 months and 6 months. On inter-group comparison, no significant differences were observed at all-time points. In adjunct to the probing depth and RAL, the radiographic area of the defect showed a similar trend in intra-group comparison and no significant difference was seen on inter-group comparison at all-time points. Conclusions: Within the limitations of the current study, it can be concluded that DFDBA did not show any improvement in the clinical and radiographic parameters in the treatment of the intrabony defects as compared to FDBA. PMID:26392690

  4. Evaluation of moxifloxacin-hydroxyapatite composite graft in the regeneration of intrabony defects: A clinical, radiographic, and microbiological study

    PubMed Central

    Nagarjuna Reddy, Y. V.; Deepika, P. C.; Venkatesh, M. P.; Rajeshwari, K. G.

    2016-01-01

    Background: The formation of new connective periodontal attachment is contingent upon the elimination or marked reduction of pathogens at the treated periodontal site. An anti-microbial agent, i.e. moxifloxacin has been incorporated into the bone graft to control infection and facilitate healing during and after periodontal therapy. Materials and Methods: By purposive sampling, 15 patients with at least two contralateral vertical defect sites were selected. The selected sites in each individual were divided randomly into test and control sites according to split-mouth design. Test site received moxifloxacin-hydroxyapatite composite graft and control site received hydroxyapatite-placebo gel composite graft. Probing depth (PD) and Clinical attachment level (CAL) were assessed at baseline, 3, 6, 9, and 12 months. Bone probing depth (BPD) and hard tissue parameters such as amount of defect fill, percentage of defect fill, and changes in alveolar crest were assessed at baseline, 6, and 12 months. Changes in subgingival microflora were also assessed by culturing the subgingival plaque samples at baseline and at 3-month follow-up. The clinical, radiographic, and microbiological data obtained were subjected to statistical analysis using descriptive statistics, paired sample t-test, independent t-test, and contingency test. Results: On intragroup comparison at test and control sites, there was a significant improvement in all clinical and radiographic parameters. However, on intergroup comparison of the same, there was no statistically significant difference between test and control sites at any interval. Although test sites showed slightly higher amount of bone fill, it was not statistically significant. There was a significant reduction in the counts of Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis at both sites from baseline to 3 months. In addition, there was a significant reduction at test sites as compared to control sites at 3-month follow-up (P

  5. Effects of concomitant use of fibroblast growth factor (FGF)-2 with beta-tricalcium phosphate ({beta}-TCP) on the beagle dog 1-wall periodontal defect model

    SciTech Connect

    Anzai, Jun; Kitamura, Masahiro; Nozaki, Takenori; Nagayasu, Toshie; Terashima, Akio; Asano, Taiji; Murakami, Shinya

    2010-12-17

    Research highlights: {yields} Concomitant use of FGF-2 and {beta}-TCP (an osteo-conductive scaffold) significantly promotes periodontal regeneration in the severe periodontitis model (1-wall defect model) of beagle dog. {yields} FGF-2 enhanced new bone formation via {beta}-TCP at the defects. {yields} In particular, FGF-2 dramatically regenerated new periodontal ligament and cementum formations at the defects, that is one of the most important healing outcomes during the process of periodontal regeneration. {yields} Epithelial downgrowth (undesirable wound healing) was decreased by administration of FGF-2. {yields} This manuscript indicates for the first time that concomitant use of FGF-2 and {beta}-TCP is efficacious in regenerating periodontal tissue following severe destruction of the tissue by progression of periodontitis. -- Abstract: The effects of concomitant use of fibroblast growth factor-2 (FGF-2) and beta-tricalcium phosphate ({beta}-TCP) on periodontal regeneration were investigated in the beagle dog 1-wall periodontal defect model. One-wall periodontal defects were created in the mesial portion of both sides of the mandibular first molars, and 0.3% FGF-2 plus {beta}-TCP or {beta}-TCP alone was administered. Radiographic evaluation was performed at 0, 3, and 6 weeks. At 6 weeks, the periodontium with the defect site was removed and histologically analyzed. Radiographic findings showed that co-administration of FGF-2 significantly increased bone mineral contents of the defect sites compared with {beta}-TCP alone. Histologic analysis revealed that the length of the regenerated periodontal ligament, the cementum, distance to the junctional epithelium, new bone height, and area of newly formed bone were significantly increased in the FGF-2 group. No abnormal inflammatory response or ankylosis was observed in either group. These findings indicate the efficacy of concomitant use of FGF-2 and {beta}-TCP as an osteoconductive material for periodontal

  6. Management of localized advance loss of periodontal support associated Grade II furcation and intrabony defect in chronic periodontitis patient through amalgamation of platelet-rich fibrin and hydroxyapatite bioactive glass composite granules

    PubMed Central

    Salaria, Sanjeev Kumar; Ghuman, Simrat Kaur; Kumar, Saurabh; Sharma, Garima

    2016-01-01

    Periodontal disease is infectious, complex, multifactorial, chronic inflammatory disease of supporting periodontal tissues that not only alters the bone morphology but also leads to the reduction in bone height. Different types of bony deformities such as horizontal, vertical, craters, and furcation result from periodontal disease, but vertical and Grade II furcation defects are more amenable to regenerative periodontal therapy. The present case report describes the current concept of periodontal diagnosis and the clinical radiographical efficiency of platelet-rich fibrin and hydroxyapatite bioactive glass composite granules graft combination in the management of localized advance osseous defects with respect to tooth number 36 in chronic periodontitis patient at 1 year postoperatively.

  7. Biomimetic hydroxyapatite used in the treatment of periodontal intrabony pockets: clinical and radiological analysis

    PubMed Central

    Figliuzzi, Michele Mario; Giudice, Amerigo; Pileggi, Settimia; Scordamaglia, Francesco; Marrelli, Massimo; Tatullo, Marco; Fortunato, Leonzio

    2016-01-01

    Summary Aim Hydroxyapatite (PA) has a chemical composition and physical structure very similar to natural bone and therefore it has been considered to be the ideal biomaterial able to ensure a biomimetic scaffold to use in bone tissue engineering. The aim of this study is to clinically test hydroxyapatite used as osteoconductive biomaterial in the treatment of periodontal bone defects. Clinical and radiological evaluations were conducted at 6, 12 and 18 months after the surgery. Materials and methods Forty patients with 2- and 3-wall intrabony pockets were enrolled in this study. PPD, CAL, radiographic depth (RD) and angular defects were preoperatively measured. After surgery, patients were re-evaluated every 6 months for 18 months. Statistical analyses were also performed to investigate any differences between preoperative and postoperative measurements. Results Paired t-test samples conducted on the data obtained at baseline and 18 months after, showed significant (p<0.01) differences in each measurement performed. The role of preoperative RD was demonstrated to be a significant key factor (p<0.01). A relevant correlation between preoperative PPD and CAL gain was also found. Conclusions Within the limitations of this study, the absence of anatomical variables, except the morphology of the bone defect, emphasizes the importance of the proper surgical approach and the graft material used. PMID:27486507

  8. Comparative evaluation of periosteum as a barrier membrane with and without an alloplastic bone graft in periodontal osseous defects: A 9 months follow-up study

    PubMed Central

    Kumar, Akhilesh; Lal, Nand; Singhal, Rameshwari; Rastogi, Pavitra

    2014-01-01

    Background: Regenerative procedures frequently include the use of barrier membranes and bone grafting materials to encourage the growth of key surrounding tissues. The present study aims to evaluate and compare the ability of periosteum in intrabony defect regeneration. Materials and Methods: A total of ten intrabony defects were equally divided in two treatment groups. Group I consisted of Periosteum used as a barrier memebrane and Group II of periosteum as barrier membrane alongwith graft material. Nine months post operative evaluation of defect fill was done radiographically. Results: Mean defect fill (CEJ-BBD) was found to be significantly lower in Group II as compared to Group I (P = 0.041). Conclusion: Within the limitations of this study, alloplastic graft material supplimentation results in better regeneration with Periosteum used as a barrier membrane. PMID:25210266

  9. Birth Defects

    MedlinePlus

    ... NICHD Research Information Clinical Trials Resources and Publications Birth Defects: Condition Information Skip sharing on social media links Share this: Page Content What are birth defects? Birth defects are structural or functional abnormalities present ...

  10. Birth Defects

    MedlinePlus

    A birth defect is a problem that happens while a baby is developing in the mother's body. Most birth defects happen during the first 3 months of ... in the United States is born with a birth defect. A birth defect may affect how the ...

  11. Ear defects.

    PubMed

    Shonka, David C; Park, Stephen S

    2009-08-01

    The projection and exposure of the auricle make it particularly susceptible to actinic injury and thus to cutaneous malignancies. Auricular reconstruction is challenging because of its unique surface anatomy and undulating topography. This article organizes auricular defects into different categories based on anatomic location and extent of tissue loss, including skin-only defects, small composite defects, full-thickness defects involving or sparing the upper third of the ear, and total auricular loss. The authors share an algorithm for repair of the array of auricular defects. PMID:19698921

  12. Birth Defects

    MedlinePlus

    ... with birth defects may need surgery or other medical treatments. Today, doctors can diagnose many birth defects in the womb. This enables them to treat or even correct some problems before the baby is born. Centers for Disease Control and Prevention

  13. Congenital Defects.

    ERIC Educational Resources Information Center

    Goldman, Allen S.; And Others

    There are two general categories (not necessarily mutually exclusive) of congenital defects: (1) abnormalities that have an hereditary basis, such as single and multiple genes, or chromosomal abberration; and (2) abnormalities that are caused by nonhereditary factors, such as malnutrition, maternal disease, radiation, infections, drugs, or…

  14. Semilocal defects

    SciTech Connect

    Preskill, J. )

    1992-11-15

    I analyze the interplay of gauge and global symmetries in the theory of topological defects. In a two-dimensional model in which both gauge symmetries and {ital exact} global symmetries are spontaneously broken, stable vortices may fail to exist even though magnetic flux is topologically conserved. Following Vachaspati and Achucarro, I formulate the condition that must be satisfied by the pattern of symmetry breakdown for finite-energy configurations to exist in which the conserved magnetic flux is spread out instead of confined to a localized vortex. If this condition is met, vortices are always unstable at sufficiently weak gauge coupling. I also describe the properties of defects in models with an accidental'' symmetry that is partially broken by gauge-boson exchange. In some cases, the spontaneously broken accidental symmetry is not restored inside the core of the defect. Then the structure of the defect can be analyzed using an effective field theory; the details of the physics responsible for the spontaneous symmetry breakdown need not be considered. Examples include domain walls and vortices that are classically unstable, but are stabilized by loop corrections, and magnetic monopoles that have an unusual core structure. Finally, I examine the general theory of the electroweak strings'' that were recently discussed by Vachaspati. These arise only in models with gauge-boson mixing,'' and can always end on magnetic monopoles. Cosmological implications are briefly discussed.

  15. Ventricular Septal Defect (VSD)

    MedlinePlus

    ... Your Risk • Symptoms & Diagnosis • Care & Treatment • Tools & Resources Web Booklets on Congenital Heart Defects These online publications ... to you or your child’s defect and concerns. Web Booklet: Adults With Congenital Heart Defects Web Booklet: ...

  16. Neural Tube Defects

    MedlinePlus

    Neural tube defects are birth defects of the brain, spine, or spinal cord. They happen in the first month ... that she is pregnant. The two most common neural tube defects are spina bifida and anencephaly. In spina bifida, ...

  17. Isolation and Assessment of Mesenchymal Stem Cells Derived From Bone Marrow: Histologic and Histomorphometric Study in a Canine Periodontal Defect.

    PubMed

    Paknejad, Mojgan; Eslaminejad, Mohamadreza Baghaban; Ghaedi, Baharak; Rokn, Amir-Reza; Khorsand, Afshin; Etemad-Moghadam, Shahroo; Alaeddini, Mojgan; Dehghan, Mohammad Mehdi; Moslemi, Neda; Nowzari, Hessam

    2015-06-01

    The aim of the present study was to investigate an isolation procedure to culture mesenchymal stem cells derived from bone marrow and evaluate their potential in periodontal regeneration. Potential stem cells from bone marrow, aspirated from the iliac crest of nine mongrel canines 1 to 2 years of age, were cultivated. After the examination of surface epitopes of the isolated cells, the total RNA from osteogenic, adipogenic, and chondrogenic cell cultures were analyzed by reverse transcription polymerase chain reaction (RT-PCR) to confirm stem cell gene expressions. 2 × 10(7) mL of the stem cells were loaded on 0.2 mL of anorganic bovine bone mineral (ABBM) granules. In each animal, bilateral acute/chronic intrabony periodontal defects were created surgically and by placement of ligatures around the cervical aspect of the teeth. At week 5, after flap debridement, the bilateral defects were randomly assigned to 2 treatment groups: the control group received ABBM, and the test group received BMSCs-loaded ABBM. Eight weeks after transplantation, regenerative parameters were analyzed histologically and histometrically. The RNA expressions confirmed the cultivation of mesenchymal stem cell. More new cementum and periodontal ligament (PDL) were measured in the test group (cementum: 3.33 ± 0.94 vs 2.03 ± 1.30, P = 0.027; PDL: 2.69 ± 0.73 vs 1.53 ± 1.21, P = 0.026). New bone formation was similar in both groups (2.70 ± 0.86 vs 1.99 ± 1.31; P = 0.193). Mesenchymal stem cells derived from bone marrow should be considered a promising technique for use in patients with periodontal attachment loss and merits further investigations. PMID:24383495

  18. Birth Defects Diagnosis

    MedlinePlus

    ... chromosomal disorder or heart defect in the baby. Second Trimester Screening Second trimester screening tests are completed between weeks 15 ... look for certain birth defects in the baby. Second trimester screening tests include a maternal serum screen ...

  19. Atrial septal defect

    MedlinePlus

    ... Coronary angiography (for patients over 35 years old) ECG Heart MRI Transesophageal echocardiography (TEE) Treatment ASD may ... of the complications can be prevented with early detection. Alternative Names Congenital heart defect - ASD; Birth defect ...

  20. Facts about Birth Defects

    MedlinePlus

    ... Us Information For... Media Policy Makers Facts about Birth Defects Language: English Español (Spanish) Recommend on Facebook Tweet ... having a baby born without a birth defect. Birth Defects Are Common Every 4 ½ minutes, a baby ...

  1. Defect production in ceramics

    SciTech Connect

    Zinkle, S.J.; Kinoshita, C.

    1997-08-01

    A review is given of several important defect production and accumulation parameters for irradiated ceramics. Materials covered in this review include alumina, magnesia, spinel silicon carbide, silicon nitride, aluminum nitride and diamond. Whereas threshold displacement energies for many ceramics are known within a reasonable level of uncertainty (with notable exceptions being AIN and Si{sub 3}N{sub 4}), relatively little information exists on the equally important parameters of surviving defect fraction (defect production efficiency) and point defect migration energies for most ceramics. Very little fundamental displacement damage information is available for nitride ceramics. The role of subthreshold irradiation on defect migration and microstructural evolution is also briefly discussed.

  2. Topological defect lasers

    NASA Astrophysics Data System (ADS)

    Knitter, Sebastian; Fatt Liew, Seng; Xiong, Wen; Guy, Mikhael I.; Solomon, Glenn S.; Cao, Hui

    2016-01-01

    We introduce a topological defect to a regular photonic crystal defect cavity with anisotropic unit cell. Spatially localized resonances are formed and have high quality factor. Unlike the regular photonic crystal defect states, the localized resonances in the topological defect structures support powerflow vortices. Experimentally we realize lasing in the topological defect cavities with optical pumping. This work shows that the spatially inhomogeneous variation of the unit cell orientation adds another degree of freedom to the control of lasing modes, enabling the manipulation of the field pattern and energy flow landscape.

  3. Postdevelopment defect evaluation

    NASA Astrophysics Data System (ADS)

    Miyahara, Osamu; Kiba, Yukio; Ono, Yuko

    2001-08-01

    Reduction of defects after development is a critical issue in photolithography. A special category of post development defects is the satellite defect which is located in large exposed areas generally in proximity to large unexposed regions of photoresist. We have investigated the formation of this defect type on ESCAP and ACETAL DUV resists with and without underlying organic BARCs, In this paper, we will present AFM and elemental analysis data to determine the origin of the satellite defect. Imaging was done on a full-field Nikon 248nm stepper and resist processing was completed on a TEL CLEAN TRACK ACT 8 track. Defect inspection and review were performed on a KLA-Tencor and Hitachi SEM respectively. Results indicate that the satellite defect is generated on both BARC and resist films and defect counts are dependent on the dark erosion. Elemental analysis indicates that the defects are composed of sulfur and nitrogen compounds. We suspect that the defect is formed as a result of a reaction between PAG, quencher and TMAH. This defect type is removed after a DIW re-rinse.

  4. Micrograph Defect Indentifier

    Energy Science and Technology Software Center (ESTSC)

    2012-10-11

    Micrograph image defect identifier is a computer code written in MATLAB to automatically detect defects on scanned image of thin film membrane samples employing three methods: global threshold, line detection and k-means segmentation. The results are segmented binary images of thin film with defects identified. Defect area fractions are also calculated. The users may use default functional variables calculated by program, or input preferred value from user’s experience. This will empower the user to processingmore » the image with more flexibility. MDI was designed to identify defects of thin films fabricated. It is also used in phase identification, porosity study on SEM, OM, TEM images. Different methods were applied in this software package: global threshold, line detection and k-means segmentation.« less

  5. Micrograph Defect Indentifier

    SciTech Connect

    None, None

    2012-10-11

    Micrograph image defect identifier is a computer code written in MATLAB to automatically detect defects on scanned image of thin film membrane samples employing three methods: global threshold, line detection and k-means segmentation. The results are segmented binary images of thin film with defects identified. Defect area fractions are also calculated. The users may use default functional variables calculated by program, or input preferred value from user’s experience. This will empower the user to processing the image with more flexibility. MDI was designed to identify defects of thin films fabricated. It is also used in phase identification, porosity study on SEM, OM, TEM images. Different methods were applied in this software package: global threshold, line detection and k-means segmentation.

  6. Defect Chemistry of Nanocarbon

    NASA Astrophysics Data System (ADS)

    Wang, Yuhuang

    2015-03-01

    Defects can rule the properties of a crystal. This effect is particularly intriguing in atom-thick materials such as single-walled carbon nanotubes and graphene, where electrons, excitons, phonons, and spin may strongly couple at the defect sites due to reduced dimensionality. In this talk, we will discuss our recent progress in fundamental understanding and molecular control of sp3 defects in sp2 carbon lattices, and their applications. An sp3 defect (tetrahedral bonding, diamond-like) is created by covalently attaching a functional group to the sp2 carbon lattice (trigonal planar, honeycomb-like) of a carbon nanotube or graphene. The beauty of this type of defect is its well-defined structure and chemical tunability at the molecular level. Our experimental results have unraveled a series of intriguing and surprising roles of defects. Specific examples will be given to illustrate how defects may be used to drive reaction propagation on sp2 carbon lattices, brighten carbon nanotube photoluminescence, and create selective chemical sensors.

  7. Wavelength dependent mask defects

    NASA Astrophysics Data System (ADS)

    Badger, Karen; Butt, Shahid; Burnham, Jay; Faure, Tom; Hibbs, Michael; Rankin, Jed; Thibault, David; Watts, Andrew

    2005-05-01

    For years there has been a mismatch between the photomask inspection wavelength and the usage conditions. While the non-actinic inspection has been a source for concern, there has been essentially no evidence that a defect "escaped" the mask production process due to the inspection mismatch. This paper will describe the discovery of one such defect, as well as the diagnostic and inspection techniques used to identify the location, analyze the composition, and determine the source of the printed wafer defect. Conventional mask inspection techniques revealed no defects, however an actinic Aerial Image Metrology System (AIMS) revealed a 1.5 mm region on the mask with up to 59% transmission reduction at 193 nm. Further diagnostics demonstrated a strong wavelength dependence which accounted for the near invisibility of the defect at I line (365 nm) or even DUV (248 nm) wavelengths, which had 0% and 5% respective transmission reductions. Using some creative imaging techniques via AIMS tool and modeling, the defect was deduced to have a three dimensional Gaussian absorption character, with total width approximately 1.5 mm. Several non-destructive diagnostic techniques were developed to determine the composition and location of the defect within the substrate. These results will be described in addition to identifying methods for ensuring product quality in the absence of actinic inspection.

  8. Defect solitons in photonic lattices.

    PubMed

    Yang, Jianke; Chen, Zhigang

    2006-02-01

    Nonlinear defect modes (defect solitons) and their stability in one-dimensional photonic lattices with focusing saturable nonlinearity are investigated. It is shown that defect solitons bifurcate out from every infinitesimal linear defect mode. Low-power defect solitons are linearly stable in lower bandgaps but unstable in higher bandgaps. At higher powers, defect solitons become unstable in attractive defects, but can remain stable in repulsive defects. Furthermore, for high-power solitons in attractive defects, we found a type of Vakhitov-Kolokolov (VK) instability which is different from the usual VK instability based on the sign of the slope in the power curve. Lastly, we demonstrate that in each bandgap, in addition to defect solitons which bifurcate from linear defect modes, there is also an infinite family of other defect solitons which can be stable in certain parameter regimes. PMID:16605473

  9. What Are Neural Tube Defects?

    MedlinePlus

    ... NICHD Research Information Clinical Trials Resources and Publications Neural Tube Defects (NTDs): Condition Information Skip sharing on ... media links Share this: Page Content What are neural tube defects? Neural (pronounced NOOR-uhl ) tube defects ...

  10. Atrial Septal Defect (For Teens)

    MedlinePlus

    ... I Help a Friend Who Cuts? Atrial Septal Defect KidsHealth > For Teens > Atrial Septal Defect Print A ... Care of Yourself What Is an Atrial Septal Defect? Having a doctor listen to your heart is ...

  11. Automated Defect Classification (ADC)

    Energy Science and Technology Software Center (ESTSC)

    1998-01-01

    The ADC Software System is designed to provide semiconductor defect feature analysis and defect classification capabilities. Defect classification is an important software method used by semiconductor wafer manufacturers to automate the analysis of defect data collected by a wide range of microscopy techniques in semiconductor wafer manufacturing today. These microscopies (e.g., optical bright and dark field, scanning electron microscopy, atomic force microscopy, etc.) generate images of anomalies that are induced or otherwise appear on wafermore » surfaces as a result of errant manufacturing processes or simple atmospheric contamination (e.g., airborne particles). This software provides methods for analyzing these images, extracting statistical features from the anomalous regions, and applying supervised classifiers to label the anomalies into user-defined categories.« less

  12. Birth Defects (For Parents)

    MedlinePlus

    ... Ones & When? Smart School Lunches Emmy-Nominated Video "Cerebral Palsy: Shannon's Story" 5 Things to Know About Zika & ... defects. Clefting can be surgically repaired after birth. Cerebral palsy usually isn't found until weeks to months ...

  13. Birth defects monitoring

    SciTech Connect

    Klingberg, M.A.; Papier, C.M.; Hart, J.

    1983-01-01

    Population monitoring of birth defects provides a means for detecting relative changes in their frequency. Many varied systems have been developed throughout the world since the thalidomide tragedy of the early 1960s. Although it is difficult to pinpoint specific teratogenic agents based on rises in rates of a particular defect or a constellation of defects, monitoring systems can provide clues for hypothesis testing in epidemiological investigations. International coordination of efforts in this area resulted in the founding of the International Clearinghouse for Birth Defects Monitoring Systems (ICBDMS) in 1974. In this paper we will describe the functions and basic requirements of monitoring systems in general, and look at the development and activities of the ICBDMS. A review of known and suspected environmental teratogenic agents (eg, chemical, habitual, biological, physical, and nutritional) is also presented.

  14. Congenital Heart Defects

    MedlinePlus

    ... Treatment can include medicines, catheter procedures, surgery, and heart transplants. The treatment depends on the type of the defect, how severe it is, and a child's age, size, and general health. NIH: National Heart, Lung, and Blood Institute

  15. Birth Defects. Matrix No. 2.

    ERIC Educational Resources Information Center

    Brent, Robert L.

    This report discusses the magnitude of the problem of birth defects, outlines advances in the birth defects field in the past decade, and identifies those areas where research is needed for the prevention, treatment, and management of birth defects. The problem of birth defects has consumed a greater portion of our health care resources because of…

  16. Reconstruction of Mandibular Defects

    PubMed Central

    Chim, Harvey; Salgado, Christopher J.; Mardini, Samir; Chen, Hung-Chi

    2010-01-01

    Defects requiring reconstruction in the mandible are commonly encountered and may result from resection of benign or malignant lesions, trauma, or osteoradionecrosis. Mandibular defects can be classified according to location and extent, as well as involvement of mucosa, skin, and tongue. Vascularized bone flaps, in general, provide the best functional and aesthetic outcome, with the fibula flap remaining the gold standard for mandible reconstruction. In this review, we discuss classification and approach to reconstruction of mandibular defects. We also elaborate upon four commonly used free osteocutaneous flaps, inclusive of fibula, iliac crest, scapula, and radial forearm. Finally, we discuss indications and use of osseointegrated implants as well as recent advances in mandibular reconstruction. PMID:22550439

  17. Wire insulation defect detector

    NASA Technical Reports Server (NTRS)

    Greulich, Owen R. (Inventor)

    2004-01-01

    Wiring defects are located by detecting a reflected signal that is developed when an arc occurs through the defect to a nearby ground. The time between the generation of the signal and the return of the reflected signal provides an indication of the distance of the arc (and therefore the defect) from the signal source. To ensure arcing, a signal is repeated at gradually increasing voltages while the wire being tested and a nearby ground are immersed in a conductive medium. In order to ensure that the arcing occurs at an identifiable time, the signal whose reflection is to be detected is always made to reach the highest potential yet seen by the system.

  18. Quantum computing with defects

    NASA Astrophysics Data System (ADS)

    Varley, Joel

    2011-03-01

    The development of a quantum computer is contingent upon the identification and design of systems for use as qubits, the basic units of quantum information. One of the most promising candidates consists of a defect in diamond known as the nitrogen-vacancy (NV-1) center, since it is an individually-addressable quantum system that can be initialized, manipulated, and measured with high fidelity at room temperature. While the success of the NV-1 stems from its nature as a localized ``deep-center'' point defect, no systematic effort has been made to identify other defects that might behave in a similar way. We provide guidelines for identifying other defect centers with similar properties. We present a list of physical criteria that these centers and their hosts should meet and explain how these requirements can be used in conjunction with electronic structure theory to intelligently sort through candidate systems. To elucidate these points, we compare electronic structure calculations of the NV-1 center in diamond with those of several deep centers in 4H silicon carbide (SiC). Using hybrid functionals, we report formation energies, configuration-coordinate diagrams, and defect-level diagrams to compare and contrast the properties of these defects. We find that the NC VSi - 1 center in SiC, a structural analog of the NV-1 center in diamond, may be a suitable center with very different optical transition energies. We also discuss how the proposed criteria can be translated into guidelines to discover NV analogs in other tetrahedrally coordinated materials. This work was performed in collaboration with J. R. Weber, W. F. Koehl, B. B. Buckley, A. Janotti, C. G. Van de Walle, and D. D. Awschalom. This work was supported by ARO, AFOSR, and NSF.

  19. Supersymmetric k-defects

    NASA Astrophysics Data System (ADS)

    Koehn, Michael; Trodden, Mark

    2016-04-01

    In supersymmetric theories, topological defects can have nontrivial behaviors determined purely by whether or not supersymmetry is restored in the defect core. A well-known example of this is that some supersymmetric cosmic strings are automatically superconducting, leading to important cosmological effects and constraints. We investigate the impact of nontrivial kinetic interactions, present in a number of particle physics models of interest in cosmology, on the relationship between supersymmetry and supercurrents on strings. We find that in some cases it is possible for superconductivity to be disrupted by the extra interactions.

  20. Neural Tube Defects

    MedlinePlus

    ... The two most common neural tube defects are spina bifida and anencephaly. In spina bifida, the fetal spinal column doesn't close completely. There is usually nerve damage that causes at least some paralysis of the legs. In anencephaly, ... National Institute of Child Health and Human Development

  1. Quantum computing with defects.

    PubMed

    Weber, J R; Koehl, W F; Varley, J B; Janotti, A; Buckley, B B; Van de Walle, C G; Awschalom, D D

    2010-05-11

    Identifying and designing physical systems for use as qubits, the basic units of quantum information, are critical steps in the development of a quantum computer. Among the possibilities in the solid state, a defect in diamond known as the nitrogen-vacancy (NV(-1)) center stands out for its robustness--its quantum state can be initialized, manipulated, and measured with high fidelity at room temperature. Here we describe how to systematically identify other deep center defects with similar quantum-mechanical properties. We present a list of physical criteria that these centers and their hosts should meet and explain how these requirements can be used in conjunction with electronic structure theory to intelligently sort through candidate defect systems. To illustrate these points in detail, we compare electronic structure calculations of the NV(-1) center in diamond with those of several deep centers in 4H silicon carbide (SiC). We then discuss the proposed criteria for similar defects in other tetrahedrally coordinated semiconductors. PMID:20404195

  2. Ventricular Septal Defect

    MedlinePlus

    ... Cardiac Rhythm Disturbances Thoracic Aortic Aneurysm Pediatric and Congenital Heart Disease Heart abnormalities that are present at birth in ... common, accounting for 20% to 30% of all congenital heart defects. The US Centers for Disease Control and Prevention (CDC) estimates that 42 out ...

  3. Defects in flexoelectric solids

    NASA Astrophysics Data System (ADS)

    Mao, Sheng; Purohit, Prashant K.

    2015-11-01

    A solid is said to be flexoelectric when it polarizes in proportion to strain gradients. Since strain gradients are large near defects, we expect the flexoelectric effect to be prominent there and decay away at distances much larger than a flexoelectric length scale. Here, we quantify this expectation by computing displacement, stress and polarization fields near defects in flexoelectric solids. For point defects we recover some well known results from strain gradient elasticity and non-local piezoelectric theories, but with different length scales in the final expressions. For edge dislocations we show that the electric potential is a maximum in the vicinity of the dislocation core. We also estimate the polarized line charge density of an edge dislocation in an isotropic flexoelectric solid which is in agreement with some measurements in ice. We perform an asymptotic analysis of the crack tip fields in flexoelectric solids and show that our results share some features from solutions in strain gradient elasticity and piezoelectricity. We also compute the energy release rate for cracks using simple crack face boundary conditions and use them in classical criteria for crack growth to make predictions. Our analysis can serve as a starting point for more sophisticated analytic and computational treatments of defects in flexoelectric solids which are gaining increasing prominence in the field of nanoscience and nanotechnology.

  4. Facts about Congenital Heart Defects

    MedlinePlus

    ... types of CHDs. The types marked with a star (*) are considered critical CHDs. Atrial Septal Defect Atrioventricular Septal Defect Coarctation of the Aorta * Double-outlet right ventricle* d-Transposition of the great ...

  5. Adults with Congenital Heart Defects

    MedlinePlus

    ... Pressure High Blood Pressure Tools & Resources Stroke More Web Booklet: Adults With Congenital Heart Defects Updated:Apr ... topic from the list below to learn more. Web Booklet: Adults With Congenital Heart Defects Introduction Introduction: ...

  6. Ventricular Septal Defect (For Parents)

    MedlinePlus

    ... of the heart and surrounding organs an electrocardiogram (EKG) , which records the electrical activity of the heart ... What to Expect Congenital Heart Defects Getting an EKG (Video) Heart Murmurs Atrial Septal Defect EKG (Video) ...

  7. Birth Defects Data and Statistics

    MedlinePlus

    ... Websites About Us Information For... Media Policy Makers Data & Statistics Language: English Español (Spanish) Recommend on Facebook ... of birth defects in the United States. For data on specific birth defects, please visit the specific ...

  8. Congenital heart defect - corrective surgery

    MedlinePlus

    ... born with one or more heart defects has congenital heart disease . Surgery is needed if the defect could harm ... 2008 Guidelines for the Management of Adults with Congenital Heart Disease: a report of the American College of Cardiology/ ...

  9. Guidance for Preventing Birth Defects

    MedlinePlus

    ... Lip and Palate Craniosynostosis Down Syndrome Eye Defects Fetal Alcohol Syndrome Disorders Gastroschisis Heart Defects Coarctation of the Aorta ... drank alcohol during the pregnancy, are known as fetal alcohol spectrum disorders (FASDs) . The best advice for women is to ...

  10. Reducing Risks of Birth Defects

    MedlinePlus

    ... Education FAQs Reducing Risks of Birth Defects Patient Education Pamphlets - Spanish Reducing Risks of Birth Defects FAQ146, February 2016 ... Your Practice Patient Safety & Quality Payment Reform (MACRA) Education & Events Annual ... Pamphlets Teen Health About ACOG About Us Leadership & ...

  11. Neural tube defects.

    PubMed

    Greene, Nicholas D E; Copp, Andrew J

    2014-01-01

    Neural tube defects (NTDs), including spina bifida and anencephaly, are severe birth defects of the central nervous system that originate during embryonic development when the neural tube fails to close completely. Human NTDs are multifactorial, with contributions from both genetic and environmental factors. The genetic basis is not yet well understood, but several nongenetic risk factors have been identified as have possibilities for prevention by maternal folic acid supplementation. Mechanisms underlying neural tube closure and NTDs may be informed by experimental models, which have revealed numerous genes whose abnormal function causes NTDs and have provided details of critical cellular and morphological events whose regulation is essential for closure. Such models also provide an opportunity to investigate potential risk factors and to develop novel preventive therapies. PMID:25032496

  12. Neural Tube Defects

    PubMed Central

    Greene, Nicholas D.E.; Copp, Andrew J.

    2015-01-01

    Neural tube defects (NTDs), including spina bifida and anencephaly, are severe birth defects of the central nervous system that originate during embryonic development when the neural tube fails to close completely. Human NTDs are multifactorial, with contributions from both genetic and environmental factors. The genetic basis is not yet well understood, but several nongenetic risk factors have been identified as have possibilities for prevention by maternal folic acid supplementation. Mechanisms underlying neural tube closure and NTDs may be informed by experimental models, which have revealed numerous genes whose abnormal function causes NTDs and have provided details of critical cellular and morphological events whose regulation is essential for closure. Such models also provide an opportunity to investigate potential risk factors and to develop novel preventive therapies. PMID:25032496

  13. Controversies in Parotid Defect Reconstruction.

    PubMed

    Tamplen, Matthew; Knott, P Daniel; Fritz, Michael A; Seth, Rahul

    2016-08-01

    Reconstruction of the parotid defect is a complex topic that encompasses restoration of both facial form and function. The reconstructive surgeon must consider facial contour, avoidance of Frey syndrome, skin coverage, tumor surveillance, potential adjuvant therapy, and facial reanimation when addressing parotid defects. With each defect there are several options within the reconstructive ladder, creating controversies regarding optimal management. This article describes surgical approaches to reconstruction of parotid defects, highlighting areas of controversy. PMID:27400838

  14. Mask Blank Defect Detection

    SciTech Connect

    Johnson, M A; Sommargren, G E

    2000-02-04

    Mask blanks are the substrates that hold the master patterns for integrated circuits. Integrated circuits are semiconductor devices, such as microprocessors (mPs), dynamic random access memory (DRAMs), and application specific integrated circuits (ASICs) that are central to the computer, communication, and electronics industries. These devices are fabricated using a set of master patterns that are sequentially imaged onto light-sensitive coated silicon wafers and processed to form thin layers of insulating and conductive materials on top of the wafer. These materials form electrical paths and transistors that control the flow of electricity through the device. For the past forty years the semiconductor industry has made phenomenal improvements in device functionality, compactness, speed, power, and cost. This progress is principally due to the exponential decrease in the minimum feature size of integrated circuits, which has been reduced by a factor of {radical}2 every three years. Since 1992 the Semiconductor Industry Association (SIA) has coordinated the efforts of producing a technology roadmap for semiconductors. In the latest document, ''The International Technology Roadmap for Semiconductors: 1999'', future technology nodes (minimum feature sizes) and targeted dates were specified and are summarized in Table 1. Lithography is the imaging technology for producing a de-magnified image of the mask on the wafer. A typical de-magnification factor is 4. Mask blank defects as small as one-eighth the equivalent minimum feature size are printable and may cause device failure. Defects might be the result of the surface preparation, such as polishing, or contamination due to handling or the environment. Table 2 shows the maximum tolerable defect sizes on the mask blank for each technology node. This downward trend puts a tremendous burden on mask fabrication, particularly in the area of defect detection and reduction. A new infrastructure for mask inspection will be

  15. Defect mapping system

    DOEpatents

    Sopori, B.L.

    1995-04-11

    Apparatus for detecting and mapping defects in the surfaces of polycrystalline materials in a manner that distinguishes dislocation pits from grain boundaries includes a laser for illuminating a wide spot on the surface of the material, a light integrating sphere with apertures for capturing light scattered by etched dislocation pits in an intermediate range away from specular reflection while allowing light scattered by etched grain boundaries in a near range from specular reflection to pass through, and optical detection devices for detecting and measuring intensities of the respective intermediate scattered light and near specular scattered light. A center blocking aperture or filter can be used to screen out specular reflected light, which would be reflected by nondefect portions of the polycrystalline material surface. An X-Y translation stage for mounting the polycrystalline material and signal processing and computer equipment accommodate rastor mapping, recording, and displaying of respective dislocation and grain boundary defect densities. A special etch procedure is included, which prepares the polycrystalline material surface to produce distinguishable intermediate and near specular light scattering in patterns that have statistical relevance to the dislocation and grain boundary defect densities. 20 figures.

  16. Defect mapping system

    DOEpatents

    Sopori, Bhushan L.

    1995-01-01

    Apparatus for detecting and mapping defects in the surfaces of polycrystalline materials in a manner that distinguishes dislocation pits from grain boundaries includes a laser for illuminating a wide spot on the surface of the material, a light integrating sphere with apertures for capturing light scattered by etched dislocation pits in an intermediate range away from specular reflection while allowing light scattered by etched grain boundaries in a near range from specular reflection to pass through, and optical detection devices for detecting and measuring intensities of the respective intermediate scattered light and near specular scattered light. A center blocking aperture or filter can be used to screen out specular reflected light, which would be reflected by nondefect portions of the polycrystalline material surface. An X-Y translation stage for mounting the polycrystalline material and signal processing and computer equipment accommodate rastor mapping, recording, and displaying of respective dislocation and grain boundary defect densities. A special etch procedure is included, which prepares the polycrystalline material surface to produce distinguishable intermediate and near specular light scattering in patterns that have statistical relevance to the dislocation and grain boundary defect densities.

  17. A Clinical and Radiographic Evaluation of Periodontal Regenerative Potential of PerioGlas®: A Synthetic, Resorbable Material in Treating Periodontal Infrabony Defects

    PubMed Central

    Chacko, Neelathil Lisa; Abraham, Sathish; Rao, H N Shama; Sridhar, N; Moon, Ninad; Barde, Dhananjay H

    2014-01-01

    Background: Study of the clinical application of bioactive glass in treating periodontal defects has been gaining momentum. Studies in the past have hypothesized that bioactive glass resulted in an improvement of bony lesion when compared with open flap debridement. Considering that there were very few studies in the Indian dental literature involving the analysis of PerioGlas®- A particulate Bioglass in intrabony defects, the present clinical trial aimed to clinically and radiographically evaluate the efficacy of PerioGlas® and compare it to open debridement as control in the treatment of human periodontal osseous (three and two wall) defects in South Indian population. Materials and Methods: Ten patients with chronic periodontitis within the age group of 30-45 years having at least two pockets with depth of ≥6 mm exhibiting vertical osseous defects were selected for the study. A total of 20 defect sites were randomly assigned to one of the two treatment modalities such that 10 sites (experimental) received PerioGlas® material after open flap debridement and 10 sites with open flap debridement (controls). Plaque index and gingival index (GI) were recorded at baseline, 6 weeks, 3 months, 6 months and 9 months, whereas probing pocket depth (PPD), clinical attachment level and gingival recession (GR) were recorded at baseline, 6 and 9 months postoperatively. Linear radiographic measurements were carried out at baseline, 6 and 9 months to evaluate the defect fill, defect resolution and change in the alveolar crest height (ACH). Results: Both experimental and control site showed a significant reduction in plaque and GI, and a slight increase in GR. The mean reduction in PPD for experimental and control site was 4.4 ± 0.34 mm and 3.2 ± 0.1 mm, respectively. Gain in clinical attachment at experimental and control site was 4.4 ± 0.21 and 3.4 ± 0.11, respectively which on comparison was statistically non-significant for both sites. The radiographic mean defect

  18. Common Tests for Congenital Heart Defects

    MedlinePlus

    ... Heart Defect - Fetal Circulation • Care & Treatment • Tools & Resources Web Booklets on Congenital Heart Defects These online publications ... to you or your child’s defect and concerns. Web Booklet: Adults With Congenital Heart Defects Web Booklet: ...

  19. Coloring with defect

    SciTech Connect

    Cowen, L.J.; Goddard, W.; Jesurum, C.E.

    1997-06-01

    An (ordinary vertex) coloring is a partition of the vertices of a graph into independent sets. The chromatic number is the minimum number of colors needed to produce such a partition. This paper considers a relaxation of coloring in which the color classes partition the vertices into subgraphs of degree at most d. d is called the defect of the coloring. A graph which admits a vertex coloring into k color classes, where each vertex is adjacent to at most d self-colored neighbors is said to be (k, d) colorable. We consider defective coloring on graphs of bounded degree, bounded genus, and bounded chromatic number, presenting complexity results and algorithms. For bounded degree graphs, a classic result of Lovasz yields a (k, [{Delta}/k]) coloring for graphs with E edges of maximum degree {Delta} in O({Delta}E) time. For graphs of bounded genus, (2, d), for d > 0 and (3,1)-coloring are proved NP-Complete, even for planar graphs. Results of easily can be transformed to (3,2) color any planar graph in linear time. We show that any toroidal graph is (3,2)- and (5, 1)-colorable, and quadratic-time algorithms are presented that find the colorings. For higher surfaces, we give a linear time algorithm to (3, {radical}12{gamma} + 6) color a graph of genus {gamma} > 2. It is also shown that any graph of genus {gamma} is ({radical}12{gamma}/(d + 1) + 6, d) colorable, and an O(d{radical}{gamma}E + V) algorithm is presented that finds the coloring. These bounds are within a constant factor of what is required for the maximum clique embeddable in the surface. Reductions from ordinary vertex coloring show that (k, d) coloring is NP-complete, and there exists an c > 0 such that no polynomial time algorithm can n{sup {epsilon}}-approximate the defective chromatic number unless P = NP. Most approximation algorithms to approximately color 3-colorable graphs can be extend to allow defects.

  20. Dipole defects in beryl

    NASA Astrophysics Data System (ADS)

    Holanda, B. A.; Cordeiro, R. C.; Blak, A. R.

    2010-11-01

    Dipole defects in gamma irradiated and thermally treated beryl (Be3Al2Si6O18) samples have been studied using the Thermally Stimulated Depolarization Currents (TSDC) technique. TSDC experiments were performed in pink (morganite), green (emerald), blue (aquamarine) and colourless (goshenite) natural beryl. TSDC spectra present dipole peaks at 190K, 220K, 280K and 310K that change after gamma irradiation and thermal treatments. In morganite samples, for thermal treatments between 700K and 1100K, the 280K peak increase in intensity and the band at 220K disappears. An increase of the 280K peak and a decrease of the 190K peak were observed in the TSDC spectra of morganite after a gamma irradiation of 25kGy performed after the thermal treatments. In the case of emerald samples, thermal treatments enhanced the 280K peak and gamma irradiation partially destroyed this band. The goshenite TSDC spectra present only one band at 280K that is not affected either by thermal treatments or by gamma irradiation. All the observed peaks are of dipolar origin because the intensity of the bands is linearly dependent on the polarization field, behaviour of dipole defects. The systematic study, by means of TSDC measurements, of ionizing irradiation effects and thermal treatments in these crystals makes possible a better understanding of the role played by the impurities in beryl crystals.

  1. [Congenital defects and incapacity].

    PubMed

    Jouve de la Barreda, Nicolás

    2009-01-01

    As a whole the congenital defects constitute an important section of the medical attention affecting near 3% of the population. A 15% of spontaneous abortions take place of which the greater frequency corresponds to the chromosome anomalies (25%) and the monogenic mutations (20%) and in a lesser extent to the effects of teratogenic agents. Between the genetic causes determining the congenital defects the mutations that affect genes acting in the early stages of development occupy a main place. These alterations can affect to homeotic genes or monogenic systems that act during the critical phases of the organogenesis. It seems evident that an alteration in the expression of a necessary gene for the appearance of a morphogenetic change constitutes the angular stone to understand resurging of a malformation or discapacity. In the last years has been demonstrated the importance of the teratogenic or environmental agents on the delicate internal physiological balance during the critical stages of the development. In this context must be included the inductive environmental factors inducing epigenetic modifications in the early stage of the development of the embryos produced by fertilization in vitro. PMID:19799481

  2. Topological defects in extended inflation

    NASA Technical Reports Server (NTRS)

    Copeland, Edmund J.; Kolb, Edward W.; Liddle, Andrew R.

    1990-01-01

    The production of topological defects, especially cosmic strings, in extended inflation models was considered. In extended inflation, the Universe passes through a first-order phase transition via bubble percolation, which naturally allows defects to form at the end of inflation. The correlation length, which determines the number density of the defects, is related to the mean size of bubbles when they collide. This mechanism allows a natural combination of inflation and large scale structure via cosmic strings.

  3. Honeycomb lattices with defects

    NASA Astrophysics Data System (ADS)

    Spencer, Meryl A.; Ziff, Robert M.

    2016-04-01

    In this paper, we introduce a variant of the honeycomb lattice in which we create defects by randomly exchanging adjacent bonds, producing a random tiling with a distribution of polygon edges. We study the percolation properties on these lattices as a function of the number of exchanged bonds using an alternative computational method. We find the site and bond percolation thresholds are consistent with other three-coordinated lattices with the same standard deviation in the degree distribution of the dual; here we can produce a continuum of lattices with a range of standard deviations in the distribution. These lattices should be useful for modeling other properties of random systems as well as percolation.

  4. New defect spectroscopies

    NASA Astrophysics Data System (ADS)

    Beling, C. D.

    2002-06-01

    This paper will review progress being made on developing more defect selective forms of positron annihilation spectroscopy (PAS) at the University of Hong Kong. The first of these, positron deep-level transient spectroscopy (PDLTS), parallels conventional deep-level transient spectroscopy (DLTS) except that the positron is used as the probe, either to tell if the defects have vacancies attached to their microstructure (type I PDLTS) or as a simple electric field probe (type II PDLTS). It is shown the more important type I PDLTS has an intrinsic problem brought about by the high donor densities required to operate electrical trap filling. The problem—namely fast positron drift out of the active deep-level region into the reverse biased junction—is suggested as having two solutions. The first is to move to higher positron beam intensities and take spectra of 10 9 events. The second is that by using lower dopant densities (<10 15 cm -3) deep levels may be filled by inter-band optical excitation thus forming the workable technique positron optical (PO)-DLTS. Other techniques briefly considered in this paper are deconvoluted-coincidence Doppler broadening spectroscopy (CDBS) and Fourier transform (FT)-CDBS. Such are seen from a different perspective than most contemporary works, which tend to concentrate on the high momentum region. It is pointed out that the additional root-of-two improvement in hardware resolution and the factor of three improvement gained through deconvolution, can produce final effective resolutions similar to ACAR. Moreover, since in deconvolution, the natural space for regularized solutions is "real crystal space"—it is suggested that the autocorrelation function B2 γ( r) be taken as the experimental CDBS data—not just because it provides easier visualization,—but because data in this form lies directly on the crystal lattice.

  5. Background Defect Density Reduction Using Automated Defect Inspection And Analysis

    NASA Astrophysics Data System (ADS)

    Weirauch, Steven C.

    1988-01-01

    Yield maintenance and improvement is a major area of concern in any integrated circuit manufacturing operation. A major aspect of this concern is controlling and reducing defect density. Obviously, large defect excursions must be immediately addressed in order to maintain yield levels. However, to enhance yields, the subtle defect mechanisms must be reduced or eliminated as well. In-line process control inspections are effective for detecting large variations in the defect density on a real time basis. Examples of in-line inspection strategies include after develop or after etch inspections. They are usually effective for detecting when a particular process segment has gone out of control. However, when a process is running normally, there exists a background defect density that is generally not resolved by in-line process control inspections. The inspection strategies that are frequently used to monitor the background defect density are offline inspections. Offline inspections are used to identify the magnitude and characteristics of the background defect density. These inspections sample larger areas of product wafers than the in-line inspections to allow identification of the defect generating mechanisms that normally occur in the process. They are used to construct a database over a period of time so that trends may be studied. This information enables engineering efforts to be focused on the mechanisms that have the greatest impact on device yield. Once trouble spots in the process are identified, the data base supplies the information needed to isolate and solve them. The key aspect to the entire program is to utilize a reliable data gathering mechanism coupled with a flexible information processing system. This paper describes one method of reducing the background defect density using automated wafer inspection and analysis. The tools used in this evaluation were the KLA 2020 Wafer Inspector, KLA Utility Terminal (KLAUT), and a new software package developed

  6. Common Types of Heart Defects

    MedlinePlus

    ... American Heart area Search by State SELECT YOUR LANGUAGE Español (Spanish) 简体中文 (Traditional Chinese) 繁体中文 (Simplified Chinese) ... heart defect, treatment options and expected results. The descriptions and pictures of common heart defects that follow ...

  7. Facts about Atrial Septal Defect

    MedlinePlus

    ... prevalence estimates for selected birth defects in the United States, 2004-2006. Birth Defects Res A Clin Mol Teratol. 2010;88(12):1008-16. Related Links Disability & Health Family Health History & Genetics Healthy Pregnancy Planning for Pregnancy A-Z ...

  8. Birth Defects Prevalence and Mortality

    EPA Science Inventory

    This indicator describes the prevalence of birth defects present at birth and mortality rates among infants in the United States between from 1999-2008 and 1979-2007, respectively. Some scientific studies have linked birth defects with environmental exposures. This indicator p...

  9. Topological defects at finite temperature

    SciTech Connect

    Bazeia, D.; Eboli, O.J.P.; Guerra, J.M. Jr.; Marques, G.C.

    1987-11-15

    We obtain the phase diagram of gauge theories by studying the influence of topologically nontrivial boundary conditions. For this reason, we develop a scheme for computing the free energy of topological defects at finite temperature. As an application, the free energy of topological defects for the minimal SU(5) model are evaluated in the semiclassical approximation.

  10. Amphoteric native defects in semiconductors

    SciTech Connect

    Walukiewicz, W.

    1989-05-22

    We show that a new concept of amphoteric native defects with strongly Fermi level dependent defect formation energy provides the basis for a unified explanation of a large variety of phenomena in semiconductors. Formation of Schottky barriers, particle irradiation induced compensation, doping-induced superlattice intermixing, and limits of free-carrier concentration find for the first time a common simple explanation.

  11. Toward Intelligent Software Defect Detection

    NASA Technical Reports Server (NTRS)

    Benson, Markland J.

    2011-01-01

    Source code level software defect detection has gone from state of the art to a software engineering best practice. Automated code analysis tools streamline many of the aspects of formal code inspections but have the drawback of being difficult to construct and either prone to false positives or severely limited in the set of defects that can be detected. Machine learning technology provides the promise of learning software defects by example, easing construction of detectors and broadening the range of defects that can be found. Pinpointing software defects with the same level of granularity as prominent source code analysis tools distinguishes this research from past efforts, which focused on analyzing software engineering metrics data with granularity limited to that of a particular function rather than a line of code.

  12. Global topological k-defects

    SciTech Connect

    Babichev, E.

    2006-10-15

    We consider global topological defects in symmetry-breaking models with a noncanonical kinetic term. Apart from a mass parameter entering the potential, one additional dimensional parameter arises in such models - a kinetic mass. The properties of defects in these models are quite different from standard global domain walls, vortices, and monopoles, if their kinetic mass scale is smaller than their symmetry-breaking scale. In particular, depending on the concrete form of the kinetic term, the typical size of such a defect can be either much larger or much smaller than the size of a standard defect with the same potential term. The characteristic mass of a nonstandard defect, which might have been formed during a phase transition in the early universe, depends on both the temperature of a phase transition and the kinetic mass.

  13. Antisite defects at oxide interfaces

    NASA Astrophysics Data System (ADS)

    Chen, Hanghui; Millis, Andrew

    We use ab initio calculations to estimate formation energies of cation (transition metal) antisite defects at oxide interfaces and to understand the basic physical effects that drive or suppress the formation of these defects. We find that antisite defects are favored in systems with substantial charge transfer across the interface, while Jahn-Teller distortions and itinerant ferromagnetism can prevent antisite defects and help stabilize atomically sharp interfaces. Our results enable identification of classes of systems that are more and less susceptible to the formation of antisite defects and motivate a range of experimental studies and further theoretical calculations to further explicate the oxide interface systems. This research was supported by National Science Foundation under Grant No. DMR-1120296 (H. Chen) and DOE-ER-046169 (A. J. Millis).

  14. Holographic Chern-Simons defects

    NASA Astrophysics Data System (ADS)

    Fujita, Mitsutoshi; Melby-Thompson, Charles M.; Meyer, René; Sugimoto, Shigeki

    2016-06-01

    We study SU( N ) Yang-Mills-Chern-Simons theory in the presence of defects that shift the Chern-Simons level from a holographic point of view by embedding the system in string theory. The model is a D3-D7 system in Type IIB string theory, whose gravity dual is given by the AdS soliton background with probe D7 branes attaching to the AdS boundary along the defects. We holographically renormalize the free energy of the defect system with sources, from which we obtain the correlation functions for certain operators naturally associated to these defects. We find interesting phase transitions when the separation of the defects as well as the temperature are varied. We also discuss some implications for the Fractional Quantum Hall Effect and for 2-dimensional QCD.

  15. Nonconsecutive Pars Interarticularis Defects.

    PubMed

    Elgafy, Hossein; Hart, Ryan C; Tanios, Mina

    2015-12-01

    Lumbar spondylolysis is a well-recognized condition occurring in adolescents because of repetitive overuse in sports. Nonconsecutive spondylolysis involving the lumbar spine is rare. In contrast to single-level pars defects that respond well to conservative treatment, there is no consensus about the management of multiple-level pars fractures; a few reports indicated that conservative management is successful, and the majority acknowledged that surgery is often required. The current study presents a rare case of pars fracture involving nonconsecutive segments and discusses the management options. In this case report, we review the patient's history, clinical examination, radiologic findings, and management, as well as the relevant literature. An 18-year-old man presented to the clinic with worsening lower back pain related to nonconsecutive pars fractures at L2 and L5. After 6 months of conservative management, diagnostic computed tomography-guided pars block was used to localize the symptomatic level at L2, which was treated surgically; the L5 asymptomatic pars fracture did not require surgery. At the last follow-up 2 years after surgery, the patient was playing baseball and basketball, and denied any back pain. This article reports a case of rare nonconsecutive pars fractures. Conservative management for at least 6 months is recommended. Successful management depends on the choice of appropriate treatment for each level. Single-photon emission computed tomography scan, and computed tomography-guided pars block are valuable preoperative tools to identify the symptomatic level in such a case. PMID:26665257

  16. 2010 Defects in Semiconductors GRC

    SciTech Connect

    Shengbai Zhang

    2011-01-06

    Continuing its tradition of excellence, this Gordon Conference will focus on research at the forefront of the field of defects in semiconductors. The conference will have a strong emphasis on the control of defects during growth and processing, as well as an emphasis on the development of novel defect detection methods and first-principles defect theories. Electronic, magnetic, and optical properties of bulk, thin film, and nanoscale semiconductors will be discussed in detail. In contrast to many conferences, which tend to focus on specific semiconductors, this conference will deal with point and extended defects in a broad range of electronic materials. This approach has proved to be extremely fruitful for advancing fundamental understanding in emerging materials such as wide-band-gap semiconductors, oxides, sp{sup 2} carbon based-materials, and photovoltaic/solar cell materials, and in understanding important defect phenomena such as doping bottleneck in nanostructures and the diffusion of defects and impurities. The program consists of about twenty invited talks and a number of contributed poster sessions. The emphasis should be on work which has yet to be published. The large amount of discussion time provides an ideal forum for dealing with topics that are new and/or controversial.

  17. Serine biosynthesis and transport defects.

    PubMed

    El-Hattab, Ayman W

    2016-07-01

    l-serine is a non-essential amino acid that is biosynthesized via the enzymes phosphoglycerate dehydrogenase (PGDH), phosphoserine aminotransferase (PSAT), and phosphoserine phosphatase (PSP). Besides its role in protein synthesis, l-serine is a potent neurotrophic factor and a precursor of a number of essential compounds including phosphatidylserine, sphingomyelin, glycine, and d-serine. Serine biosynthesis defects result from impairments of PGDH, PSAT, or PSP leading to systemic serine deficiency. Serine biosynthesis defects present in a broad phenotypic spectrum that includes, at the severe end, Neu-Laxova syndrome, a lethal multiple congenital anomaly disease, intermediately, infantile serine biosynthesis defects with severe neurological manifestations and growth deficiency, and at the mild end, the childhood disease with intellectual disability. A serine transport defect resulting from deficiency of the ASCT1, the main transporter for serine in the central nervous system, has been recently described in children with neurological manifestations that overlap with those observed in serine biosynthesis defects. l-serine therapy may be beneficial in preventing or ameliorating symptoms in serine biosynthesis and transport defects, if started before neurological damage occurs. Herein, we review serine metabolism and transport, the clinical, biochemical, and molecular aspects of serine biosynthesis and transport defects, the mechanisms of these diseases, and the potential role of serine therapy. PMID:27161889

  18. Defect dynamics in active nematics

    PubMed Central

    Giomi, Luca; Bowick, Mark J; Mishra, Prashant; Sknepnek, Rastko; Cristina Marchetti, M

    2014-01-01

    Topological defects are distinctive signatures of liquid crystals. They profoundly affect the viscoelastic behaviour of the fluid by constraining the orientational structure in a way that inevitably requires global changes not achievable with any set of local deformations. In active nematic liquid crystals, topological defects not only dictate the global structure of the director, but also act as local sources of motion, behaving as self-propelled particles. In this article, we present a detailed analytical and numerical study of the mechanics of topological defects in active nematic liquid crystals. PMID:25332389

  19. Self healing of defected graphene

    SciTech Connect

    Chen, Jianhui; Shi, Tuwan; Cai, Tuocheng; Wu, Xiaosong; Yu, Dapeng; Xu, Tao; Sun, Litao

    2013-03-11

    For electronics applications, defects in graphene are usually undesirable because of their ability to scatter charge carriers, thereby reduce the carrier mobility. It would be extremely useful if the damage can be repaired. In this work, we employ Raman spectroscopy, X-ray photoemission spectroscopy, transmission electron microscopy, and electrical measurements to study defects in graphene introduced by argon plasma bombardment. We have found that majority of these defects can be cured by a simple thermal annealing process. The self-healing is attributed to recombination of mobile carbon adatoms with vacancies. With increasing level of plasma induced damage, the self-healing becomes less effective.

  20. Folic acid and birth defect prevention

    MedlinePlus

    ... of certain birth defects. These include spina bifida, anencephaly, and some heart defects. Experts recommend women who ... Women who have had a baby with a neural tube defect may need a higher dose of folic acid. ...

  1. Care and Treatment for Congenital Heart Defects

    MedlinePlus

    ... Physical Activity Recommendations for Heart Health • Tools & Resources Web Booklets on Congenital Heart Defects These online publications ... to you or your child’s defect and concerns. Web Booklet: Adults With Congenital Heart Defects Web Booklet: ...

  2. Effects of defects in composite structures

    NASA Technical Reports Server (NTRS)

    Sendeckyj, G. P.

    1983-01-01

    The effect of defects in composite structures is addressed. Defects in laminates such as wrinkles, foreign particles, scratches and breaks are discussed. Effects of plygap plywaviness and machining defects are also studied.

  3. Reproduction and Survival After Cardiac Defect Repair

    ClinicalTrials.gov

    2016-02-17

    Cardiovascular Diseases; Heart Diseases; Defect, Congenital Heart; Aortic Valve Stenosis; Transposition of Great Vessels; Ductus Arteriosus, Patent; Heart Septal Defects, Atrial; Heart Septal Defects, Ventricular; Down Syndrome; Tetralogy of Fallot; Pulmonic Stenosis; Coarctation of Aorta

  4. EUVL defect printability: an industry challenge

    NASA Astrophysics Data System (ADS)

    Kwon, Hyuk Joo; Teki, Ranganath; Harris-Jones, Jenah; Cordes, Aaron

    2012-02-01

    Extreme ultraviolet (EUV) patterning appears feasible using currently available EUV exposure tools, but some issues must still be resolved for EUV patterning to be used in production. Defects in EUV mask blanks are one such major issue, as evidenced by the research focused on defect printability. Inspection tools are needed to detect phase defects on EUV mask blanks that could possibly print on the wafer. Currently available inspection tools can capture defects on the mask, but they also need to be able to classify possible printable defects. Defect classification for repair and mitigation of printable defects is very difficult using DUV inspection tools; however, if the actinic inspection tool (AIT) could gather defect information from more multilayer stacks, it may be able to separate printable defects from unprintable defects. If unprintable defects could be eliminated, the defect information could be used for mask pattern shifts to reduce printable defects. Fewer defects would need to be repaired if there were a better chance of capturing printable defects using an actinic inspection tool. Being able to detect printable defects on EUV blanks is therefore critical in mask making. In this paper, we describe the characterization of native phase defects in the manufacturing of EUV mask blanks using the state-of-the-art mask metrology equipment in SEMATECH's Mask Blank Development Center (MBDC). Commercially available quartz substrates were used and Mo/Si multilayers were deposited on the substrates to characterize phase defects. Programmed defects of various dimensions were also prepared using e-beam patterning technology on which multilayers were deposited. Transmission electron microscopy (TEM) was used to study multilayer profile changes, while SEMATECH's AIT was used to image defects and predict their printability. A defect library for native defects and printability of programmed phase defects is introduced. Finally technical challenges for EUV defect

  5. Congenital Heart Defects (For Parents)

    MedlinePlus

    ... in utero. previous continue Common Heart Defects (cont.) Patent Ductus Arteriosus (PDA) The ductus arteriosus is a ... newborn's lungs. PDA is common in premature babies . Patent Foramen Ovale (PFO) The patent foramen ovale is ...

  6. Facts about Ventricular Septal Defect

    MedlinePlus

    ... The size of the ventricular septal defect will influence what symptoms, if any, are present, and whether ... this image. Close Information For... Media Policy Makers Language: English Español (Spanish) File Formats Help: How do ...

  7. Sequential detection of web defects

    DOEpatents

    Eichel, Paul H.; Sleefe, Gerard E.; Stalker, K. Terry; Yee, Amy A.

    2001-01-01

    A system for detecting defects on a moving web having a sequential series of identical frames uses an imaging device to form a real-time camera image of a frame and a comparitor to comparing elements of the camera image with corresponding elements of an image of an exemplar frame. The comparitor provides an acceptable indication if the pair of elements are determined to be statistically identical; and a defective indication if the pair of elements are determined to be statistically not identical. If the pair of elements is neither acceptable nor defective, the comparitor recursively compares the element of said exemplar frame with corresponding elements of other frames on said web until one of the acceptable or defective indications occur.

  8. Impact of Congenital Heart Defects

    MedlinePlus

    ... complex lesions, limitations are common. Some children with congenital heart disease have developmental delay or other learning difficulties. What ... defects? Successful treatment requires highly specialized care. Severe congenital heart disease requires extensive financial resources both in and out ...

  9. Stable line defects in silicene

    NASA Astrophysics Data System (ADS)

    Ghosh, Dibyajyoti; Parida, Prakash; Pati, Swapan K.

    2015-11-01

    Line defects in two-dimensional (2D) materials greatly modulate various properties of their pristine form. Using ab initio molecular dynamics (AIMD) simulations, we investigate the structural reconstructions of different kinds of grain boundaries in the silicene sheets. It is evident that depending upon the presence of silicon adatoms and edge shape of grain boundaries (i.e., armchair or zigzag), stable extended line defects (ELDs) can be introduced in a controlled way. Further studies show the stability of these line-defects in silicene, grown on Ag(111) surface at room-temperature. Importantly, unlike most of the 2D sheet materials such as graphene and hexagonal boron nitride, 5-5-8 line defects modify the nonmagnetic semimetallic pristine silicene sheet to spin-polarized metal. As ferromagnetically ordered magnetic moments remain strongly localized at the line defect, a one-dimensional spin channel gets created in silicene. Interestingly, these spin channels are quite stable because, unlike the edge of nanoribbons, structural reconstruction or contamination cannot destroy the ordering of magnetic moments here. Zigzag silicene nanoribbons with a 5-5-8 line defect also exhibit various interesting electronic and magnetic properties depending upon their width as well as the nature of the magnetic coupling between edge and defect spin states. Upon incorporation of other ELDs, such as 4-4-4 and 4-8 defects, 2D sheets and nanoribbons of silicene show a nonmagnetic metallic or semiconducting ground state. Highlighting the controlled formation of ELDs and consequent emergence of technologically important properties in silicene, we propose new routes to realize silicene-based nanoelectronic and spintronic devices.

  10. Topological defects from the multiverse

    NASA Astrophysics Data System (ADS)

    Zhang, Jun; Blanco-Pillado, Jose J.; Garriga, Jaume; Vilenkin, Alexander

    2015-05-01

    Many theories of the early universe predict the existence of a multiverse where bubbles continuously nucleate giving rise to observers in their interior. In this paper, we point out that topological defects of several dimensionalities will also be produced in de Sitter like regions of the multiverse. In particular, defects could be spontaneously nucleated in our parent vacuum. We study the evolution of these defects as they collide with and propagate inside of our bubble. We estimate the present distribution of defects in the observable part of the universe. The expected number of such nearby defects turns out to be quite small, even for the highest nucleation rate. We also study collisions of strings and domain walls with our bubble in our past light cone. We obtain simulated full-sky maps of the loci of such collisions, and find their angular size distribution. Similarly to what happens in the case of bubble collisions, the prospect of detecting any collisions of our bubble with ambient defects is greatly enhanced in the case where the cosmological constant of our parent vacuum is much higher than the vacuum energy density during inflation in our bubble.

  11. Topological defects from the multiverse

    SciTech Connect

    Zhang, Jun; Blanco-Pillado, Jose J.; Garriga, Jaume; Vilenkin, Alexander

    2015-05-28

    Many theories of the early universe predict the existence of a multiverse where bubbles continuously nucleate giving rise to observers in their interior. In this paper, we point out that topological defects of several dimensionalities will also be produced in de Sitter like regions of the multiverse. In particular, defects could be spontaneously nucleated in our parent vacuum. We study the evolution of these defects as they collide with and propagate inside of our bubble. We estimate the present distribution of defects in the observable part of the universe. The expected number of such nearby defects turns out to be quite small, even for the highest nucleation rate. We also study collisions of strings and domain walls with our bubble in our past light cone. We obtain simulated full-sky maps of the loci of such collisions, and find their angular size distribution. Similarly to what happens in the case of bubble collisions, the prospect of detecting any collisions of our bubble with ambient defects is greatly enhanced in the case where the cosmological constant of our parent vacuum is much higher than the vacuum energy density during inflation in our bubble.

  12. Core hysteresis in nematic defects

    NASA Astrophysics Data System (ADS)

    Kralj, Samo; Virga, Epifanio G.

    2002-08-01

    We study field-induced transformations in the biaxial core of a nematic disclination with strength m=1, employing the Landau-de Gennes order tensor parameter Q. We first consider the transition from the defectless escaped radial structure into the structure hosting a line defect with a negative uniaxial order parameter along the axis of a cylinder of radius R. The critical field of the transition monotonically increases with R and asymptotically approaches a value corresponding to ξb/ξf~0.3, where the correlation lengths ξb and ξf are related to the biaxial order and the external field, respectively. Then, in the same geometry, we focus on the line defect structure with a positive uniaxial ordering along the axis, surrounded by the uniaxial sheath, the uniaxial cylinder of radius ξu with negative order parameter and director in the transverse direction. We study the hysteresis in the position of the uniaxial sheath upon increasing and decreasing the field strength. In general, two qualitatively different solutions exist, corresponding to the uniaxial sheath located close to the defect symmetry axis or close to the cylinder wall. This latter solution exists only for strong enough anchorings. The uniaxial sheath is for a line defect what the uniaxial ring is for a point defect: by resorting to an approximate analytic estimate, we show that essentially the same hysteresis exhibited by the uniaxial sheath is expected to occur at the uniaxial ring in the core structure of a point defect.

  13. Defects formation and wave emitting from defects in excitable media

    NASA Astrophysics Data System (ADS)

    Ma, Jun; Xu, Ying; Tang, Jun; Wang, Chunni

    2016-05-01

    Abnormal electrical activities in neuronal system could be associated with some neuronal diseases. Indeed, external forcing can cause breakdown even collapse in nervous system under appropriate condition. The excitable media sometimes could be described by neuronal network with different topologies. The collective behaviors of neurons can show complex spatiotemporal dynamical properties and spatial distribution for electrical activities due to self-organization even from the regulating from central nervous system. Defects in the nervous system can emit continuous waves or pulses, and pacemaker-like source is generated to perturb the normal signal propagation in nervous system. How these defects are developed? In this paper, a network of neurons is designed in two-dimensional square array with nearest-neighbor connection type; the formation mechanism of defects is investigated by detecting the wave propagation induced by external forcing. It is found that defects could be induced under external periodical forcing under the boundary, and then the wave emitted from the defects can keep balance with the waves excited from external forcing.

  14. Effective actions for bosonic topological defects

    NASA Technical Reports Server (NTRS)

    Gregory, Ruth

    1990-01-01

    A gauge field theory is considered which admits p-dimensional topological defects, expanding the equations of motion in powers of the defect thickness. In this way an effective action and effective equation of motion is derived for the defect in terms of the coordinates of the p-dimensional worldsurface defined by the history of the core of the defect.

  15. Defects in conformal field theory

    NASA Astrophysics Data System (ADS)

    Billò, Marco; Gonçalves, Vasco; Lauria, Edoardo; Meineri, Marco

    2016-04-01

    We discuss consequences of the breaking of conformal symmetry by a flat or spherical extended operator. We adapt the embedding formalism to the study of correlation functions of symmetric traceless tensors in the presence of the defect. Two-point functions of a bulk and a defect primary are fixed by conformal invariance up to a set of OPE coefficients, and we identify the allowed tensor structures. A correlator of two bulk primaries depends on two cross-ratios, and we study its conformal block decomposition in the case of external scalars. The Casimir equation in the defect channel reduces to a hypergeometric equation, while the bulk channel blocks are recursively determined in the light-cone limit. In the special case of a defect of codimension two, we map the Casimir equation in the bulk channel to the one of a four-point function without defect. Finally, we analyze the contact terms of the stress-tensor with the extended operator, and we deduce constraints on the CFT data. In two dimensions, we relate the displacement operator, which appears among the contact terms, to the reflection coefficient of a conformal interface, and we find unitarity bounds for the latter.

  16. Defects in ZnO

    NASA Astrophysics Data System (ADS)

    McCluskey, M. D.; Jokela, S. J.

    2009-10-01

    Zinc oxide (ZnO) is a wide band gap semiconductor with potential applications in optoelectronics, transparent electronics, and spintronics. The high efficiency of UV emission in this material could be harnessed in solid-state white lighting devices. The problem of defects, in particular, acceptor dopants, remains a key challenge. In this review, defects in ZnO are discussed, with an emphasis on the physical properties of point defects in bulk crystals. As grown, ZnO is usually n-type, a property that was historically ascribed to native defects. However, experiments and theory have shown that O vacancies are deep donors, while Zn interstitials are too mobile to be stable at room temperature. Group-III (B, Al, Ga, and In) and H impurities account for most of the n-type conductivity in ZnO samples. Interstitial H donors have been observed with IR spectroscopy, while substitutional H donors have been predicted from first-principles calculations but not observed directly. Despite numerous reports, reliable p-type conductivity has not been achieved. Ferromagnetism is complicated by the presence of secondary phases, grain boundaries, and native defects. The famous green luminescence has several possible origins, including Cu impurities and Zn vacancies. The properties of group-I (Cu, Li, and Na) and group-V (N, P, As, and Sb) acceptors, and their complexes with H, are discussed. In the future, doping of ZnO nanocrystals will rely on an understanding of these fundamental properties.

  17. Defect CFTs and holographic multiverse

    SciTech Connect

    Fiol, Bartomeu

    2010-07-01

    We investigate some aspects of a recent proposal for a holographic description of the multiverse. Specifically, we focus on the implications on the suggested duality of the fluctuations of a bubble separating two universes with different cosmological constants. We do so by considering a similar problem in a 2+1 CFT with a codimension one defect, obtained by an M5-brane probe embedding in AdS{sub 4} × S{sup 7}, and studying its spectrum of fluctuations. Our results suggest that the kind of behavior required by the spectrum of bubble fluctuations is not likely to take place in defect CFTs with an AdS dual, although it might be possible if the defect supports a non-unitary theory.

  18. Topological defects on the lattice

    NASA Astrophysics Data System (ADS)

    Aasen, David; Mong, Roger; Fendley, Paul

    We construct defects in two-dimensional classical lattice models and one-dimensional quantum chains that are topologically invariant in the continuum limit. We show explicitly that these defect lines and their trivalent junctions commute with the transfer matrix/Hamiltonian. The resulting splitting and joining properties of the defect lines are exactly those of anyons in a topological phase. One useful consequence is an explicit definition of twisted boundary conditions that yield the precise shift in momentum quantization, and so provide a natural way of relating microscopic and macroscopic properties. Another is a generalization of Kramers-Wannier duality to a wide class of height models. Even more strikingly, we derive the modular transformation matrices explicitly and exactly from purely lattice considerations. We develop this construction for a variety of examples including the two-dimensional Ising model. Institute for Quantum Information and Matter, an NSF physics frontier center with support from the Moore Foundation. NSERC-PGSD.

  19. [Visual field defects in hydrocephalus].

    PubMed

    Kojima, N; Tamaki, N; Hosoda, K; Matsumoto, S

    1985-03-01

    Eight patients representing visual field defects associated with hydrocephalus are reviewed. Seven cases had aqueductal stenosis and one had congenital communicating hydrocephalus. We found five cases of defects in visual field typical of a chiasmal or optic nerve lesion: (1) inferior altitudinal hemianopia with inferior nasal quadrantanopia in the opposite eye; (2) inferior binasal quadrantanopia; (3) unilateral inferior nasal depression; (4) unilateral temporal defect; (5) bilateral central scotoma. In these cases CT demonstrated moderate or marked symmetrical dilatation of the third and lateral ventricles. Four out of five cases showed bulging of the third ventricle anteriorly into the sella turcica on CT or ventriculography. Other three patients had incongruous homonymous hemianopia. Characteristic asymmetrical dilatation of the lateral ventricles was noted in all three cases. The more enlarged lateral ventricles were ipsilateral with the affected visual pathways. The sites of lesion responsible for these field defects seemed to be optic tract in one case and optic radiation in two cases. Ventriculoperitoneal shunt was placed in five out of seven cases. Impaired visual field improved in three patients after shunt insertion. A 28-year-old female who had history of blurred vision fos 14 days showed improvement in visual acuity and field when the enlarged ventricles became slit-like by shunting. In the other two patients defects in visual fields improved in spite of consistent ventriculomegaly. These facts suggested that not only the mechanical forces with distended third ventricle but also increased intracranial pressure played an important role in producing visual field defects in hydrocephalic patients. PMID:3874634

  20. Interface effects on calculated defect levels for oxide defects

    NASA Astrophysics Data System (ADS)

    Edwards, Arthur; Barnaby, Hugh; Schultz, Peter; Pineda, Andrew

    2014-03-01

    Density functional theory (DFT) has had impressive recent success predicting defect levels in insulators and semiconductors [Schultz and von Lillienfeld, 2009]. Such success requires care in accounting for long-range electrostatic effects. Recently, Komsa and Pasquarello have started to address this problem in systems with interfaces. We report a multiscale technique for calculating electrostatic energies for charged defects in oxide of the metal-oxide-silicon (MOS) system, but where account is taken of substrate doping density, oxide thickness, and gate bias. We use device modeling to calculate electric fields for a point charge a fixed distance from the interface, and used the field to numerically calculate the long-range electrostatic interactions. We find, for example, that defect levels in the oxide do depend on both the magnitude and the polarity the substrate doping density. Furthermore, below 20 Å, oxide thickness also has significant effects. So, transferring results directly from bulk calculations leads to inaccuracies up to 0.5 eV- half of the silicon band gap. We will present trends in defect levels as a function of device parameters. We show that these results explain previous experimental results, and we comment on their potential impact on models for NBTI. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the United States Department of Energy's National Nuclear Security Administration under co.

  1. Defects in metals. [Positron annihilation spectroscopy

    SciTech Connect

    Siegel, R.W.

    1982-06-01

    The application of positron annihilation spectroscopy (PAS) to the study of defects in metals has led to increased knowledge on lattice-defect properties during the past decade in two areas: the determination of atomic defect properties, particularly those of monovacancies, and the monitoring and characterization of vacancy-like microstructure development during post-irradiation and post-quench annealing. The study of defects in metals by PAS is reviewed within the context of the other available techniques for defect studies. The strengths and weaknesses of PAS as a method for the characterization of defect microstructures are considered. The additional possibilities for using the positron as a localized probe of the atomic and electronic structures of atomic defects are discussed, based upon theoretical calculations of the annihilation characteristics of defect-trapped positrons and experimental observations. Finally, the present status and future potential of PAS as a tool for the study of defects in metals is considered. 71 references, 9 figures.

  2. Screening Tests for Birth Defects

    MedlinePlus

    Member Login Join Pay Dues Follow us: Women's Health Care Physicians Contact Us My ACOG ACOG Departments Donate Shop Career Connection Home Resources & Publications Practice Management Education & Events Advocacy For Patients About ACOG Screening Tests for Birth Defects Home For Patients Search FAQs ...

  3. Photographic Screening for Eye Defects

    NASA Technical Reports Server (NTRS)

    Richardson, J.

    1985-01-01

    Images of retinas examined for characteristic patterns. Color photographs of retinas taken. Proper alinement of eye obtained by asking subject to gaze at light-emitting diode. "Red-eye" patterns in resulting color photographs examined by trained observers for signs of ocular defects. System used to check power of contact lenses and eyeglasses by taking photographs with these items in place.

  4. Birth Defects and Adolescent Pregnancies

    ERIC Educational Resources Information Center

    Walters, James

    1975-01-01

    Home economists who work with adolescents can help prepare them for responsible parenthood later in life by explaining the known causes of various birth defects; providing basic information about human genetics, prenatal nutrition, and drug and alcohol effects; and motivating adolescents to exercise increased responsibility in their sexual…

  5. Birth Defects Research and Tracking

    MedlinePlus

    ... support families affected by them. Read about the work taking place in each state » National Birth Defects Prevention Network (NBDPN) CDC supports and collaborates with the NBDPN. The NBDPN is a group of over 225 individuals working at the national, state, and local levels, who ...

  6. Defect Location Using Capacitative Imaging

    NASA Astrophysics Data System (ADS)

    Diamond, G. G.; Hutchins, D. A.; Gan, T. H.

    2008-02-01

    Further details of a novel capacitance sensing technique are presented, which is capable of imaging defects within a range of materials, including insulators, conductors and fibre reinforced composites. Representative results from each of these separate classes of material are presented here as are the results of real-life field trials in the inspection of civil structures.

  7. Brane inflation and defect formation.

    PubMed

    Davis, Anne-Christine; Brax, Philippe; van de Bruck, Carsten

    2008-08-28

    Brane inflation and the production of topological defects at the end of the inflationary phase are discussed. After a description of the inflationary set-up, we discuss the properties of the cosmic strings produced at the end of inflation. Specific examples of brane inflation are described, such as D-D , D3/D7 and modular inflations. PMID:18534933

  8. Thermal properties of defect melting

    NASA Astrophysics Data System (ADS)

    Ami, S.; Hofsäss, T.; Horsley, R.

    1984-03-01

    Using mean field theory and high temperature expansions the transition temperature, entropy jump and heat capacity are calculated in the recent microscopic model of defect melting proposed by Kleinert. The results are compared with the experimental data for almost isotropic substances.

  9. Surface defects on thin cryosections.

    PubMed

    Frederik, P M; Busing, W M; Persson, A

    1984-01-01

    The electron microscopic observation of thin cryosections is frequently impaired by the occurrence of surface defects. To investigate the possible causes of these surface defects the structure of cryosections ( CTEM ) from frozen biological material was correlated with the structure of the block-face (SEM) from which the sections were obtained. Both sections and block-face showed steps with a periodicity larger than 0.5 micron. Upon dry sectioning of hard plastic comparable features were observed in the section ( CTEM /SEM) and block-face (SEM). Thin cryosections cut below 143 K were found to be smooth apart from defects introduced by imperfections of the knife. In addition to "long" wave length distortions, a periodical distortion smaller than 120 nm can be observed in cryosections from biological material. At a given temperature the frequency is related to the sectioning speed. At all sectioning temperatures studied, distortions of this high frequency/short wave length type have been observed although they were less conspicuous in thinner sections. The surface defects observed in cryosections from biological material resemble the defects found after metal cutting and chip-formation. Shear forces seem to be the main causes for the observed periodic deformations on both cryosections as well as on sections from metals and plastics. This may imply that material is collected and periodically shedded from a dead zone around the knife edge. In metal cutting such a dead zone can have the form of a built-up-edge on top of the knife or as a small overhang in front of the knife edge. PMID:6377477

  10. Defects and disorder in metal organic frameworks.

    PubMed

    Cheetham, Anthony K; Bennett, Thomas D; Coudert, François-Xavier; Goodwin, Andrew L

    2016-03-14

    The wide-ranging properties of metal organic frameworks (MOFs) rely in many cases on the presence of defects within their structures and the disorder that is inevitably associated with such defects. In the present work we review several aspects of defects in MOFs, ranging from simple substitutional defects at metal cation or ligand positions, to correlated defects on a larger length scale and the extreme case of disorder associated with amorphous MOFs. We consider both porous and dense MOFs, and focus particularly on the way in which defects and disorder can be used to tune physical properties such as gas adsorption, catalysis, photoluminescence, and electronic and mechanical properties. PMID:26836459

  11. Instabilities, defects, and defect ordering in an overdamped active nematic.

    PubMed

    Putzig, Elias; Redner, Gabriel S; Baskaran, Arvind; Baskaran, Aparna

    2016-05-01

    We consider a phenomenological continuum theory for an extensile, overdamped active nematic liquid crystal, applicable in the dense regime. Constructed from general principles, the theory is universal, with parameters independent of any particular microscopic realization. We show that it exhibits two distinct instabilities, one of which arises due to shear forces, and the other due to active torques. Both lead to the proliferation of defects. We focus on the active torque bend instability and find three distinct nonequilibrium steady states including a defect-ordered nematic in which +½ disclinations develop polar ordering. We characterize the phenomenology of these phases and identify the relationship of this theoretical description to experimental realizations and other theoretical models of active nematics. PMID:26983376

  12. 3D surface defect analysis and evaluation

    NASA Astrophysics Data System (ADS)

    Yang, B.; Jia, M.; Song, G. J.; Tao, L.; Harding, K. G.

    2008-08-01

    A method is proposed for surface defect analysis and evaluation. Good 3D point clouds can now be obtained through a variety of surface profiling methods such as stylus tracers, structured light, or interferometry. In order to inspect a surface for defects, first a reference surface that represents the surface without any defects needs to be identified. This reference surface can then be fit to the point cloud. The algorithm we present finds the least square solution for the overdetermined equation set to obtain the parameters of the reference surface mathematical description. The distance between each point within the point cloud and the reference surface is then calculated using to the derived reference surface equation. For analysis of the data, the user can preset a threshold distance value. If the calculated distance is bigger than the threshold value, the corresponding point is marked as a defect point. The software then generates a color-coded map of the measured surface. Defect points that are connected together are formed into a defect-clustering domain. Each defect-clustering domain is treated as one defect area. We then use a clustering domain searching algorithm to auto-search all the defect areas in the point cloud. The different critical parameters used for evaluating the defect status of a point cloud that can be calculated are described as: P-Depth,a peak depth of all defects; Defect Number, the number of surface defects; Defects/Area, the defect number in unit area; and Defect Coverage Ratio which is a ratio of the defect area to the region of interest.

  13. 7 CFR 51.2659 - Condition defects.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Standards for Grades for Sweet Cherries 1 Definitions § 51.2659 Condition defects. Condition defects means... soft cherries and such factors as pitting, shriveling, sunken areas, brown discoloration and...

  14. Dental Enamel Defects and Celiac Disease

    MedlinePlus

    ... Nutrition Home : Dental Enamel Defects and Celiac Disease Dental Enamel Defects and Celiac Disease Celiac disease manifestations ... affecting any organ or body system. One manifestation—dental enamel defects—can help dentists and other health ...

  15. 16 CFR 1115.4 - Defect.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... understanding the concept of defect as used in the CPSA, the following examples are offered: (a) An electric... hazard it presents. The kite contains a design defect. (d) A power tool is not accompanied by...

  16. Understand Your Risk for Congenital Heart Defects

    MedlinePlus

    ... health problems than their parents. Learn more about genetic counseling . Single gene: Rarely, congenital heart defects are caused ... of Congenital Heart Defects • Understand Your Risk Introduction Genetic Counseling • Symptoms & Diagnosis • Care & Treatment • Tools & Resources Related Sites ...

  17. METROPOLITAN ATLANTA CONGENITAL DEFECTS PROGRAM (MACDP)

    EPA Science Inventory

    The Metropolitan Atlanta Congenital Defects Program (MACDP) was established in 1967 by the Centers for Disease Control and Prevention with Emory University and the Georgia Mental Health Institute as the nation's first population-based active ascertainment birth defects surveillan...

  18. Defect characterization in plastically deformed gallium arsenide

    SciTech Connect

    Leipner, H.S.; Huebner, C.; Storbeck, O.; Polity, A.; Krause-Rehberg, R.

    1996-12-31

    The defect spectrum in plastically deformed GaAs is analyzed by positron lifetime measurements. Different types of defects, such as vacancy clusters or antisites, are identified and their thermal annealing behavior is studied.

  19. Automatic classification of blank substrate defects

    NASA Astrophysics Data System (ADS)

    Boettiger, Tom; Buck, Peter; Paninjath, Sankaranarayanan; Pereira, Mark; Ronald, Rob; Rost, Dan; Samir, Bhamidipati

    2014-10-01

    Mask preparation stages are crucial in mask manufacturing, since this mask is to later act as a template for considerable number of dies on wafer. Defects on the initial blank substrate, and subsequent cleaned and coated substrates, can have a profound impact on the usability of the finished mask. This emphasizes the need for early and accurate identification of blank substrate defects and the risk they pose to the patterned reticle. While Automatic Defect Classification (ADC) is a well-developed technology for inspection and analysis of defects on patterned wafers and masks in the semiconductors industry, ADC for mask blanks is still in the early stages of adoption and development. Calibre ADC is a powerful analysis tool for fast, accurate, consistent and automatic classification of defects on mask blanks. Accurate, automated classification of mask blanks leads to better usability of blanks by enabling defect avoidance technologies during mask writing. Detailed information on blank defects can help to select appropriate job-decks to be written on the mask by defect avoidance tools [1][4][5]. Smart algorithms separate critical defects from the potentially large number of non-critical defects or false defects detected at various stages during mask blank preparation. Mechanisms used by Calibre ADC to identify and characterize defects include defect location and size, signal polarity (dark, bright) in both transmitted and reflected review images, distinguishing defect signals from background noise in defect images. The Calibre ADC engine then uses a decision tree to translate this information into a defect classification code. Using this automated process improves classification accuracy, repeatability and speed, while avoiding the subjectivity of human judgment compared to the alternative of manual defect classification by trained personnel [2]. This paper focuses on the results from the evaluation of Automatic Defect Classification (ADC) product at MP Mask

  20. Defect tolerant transmission lithography mask

    DOEpatents

    Vernon, Stephen P.

    2000-01-01

    A transmission lithography mask that utilizes a transparent substrate or a partially transparent membrane as the active region of the mask. A reflective single layer or multilayer coating is deposited on the membrane surface facing the illumination system. The coating is selectively patterned (removed) to form transmissive (bright) regions. Structural imperfections and defects in the coating have negligible effect on the aerial image of the mask master pattern since the coating is used to reflect radiation out of the entrance pupil of the imaging system. Similarly, structural imperfections in the clear regions of the membrane have little influence on the amplitude or phase of the transmitted electromagnetic fields. Since the mask "discards," rather than absorbs, unwanted radiation, it has reduced optical absorption and reduced thermal loading as compared to conventional designs. For EUV applications, the mask circumvents the phase defect problem, and is independent of the thermal load during exposure.

  1. Window defect planar mapping technique

    NASA Technical Reports Server (NTRS)

    Minton, F. R.; Minton, U. O. (Inventor)

    1976-01-01

    A method of planar mapping defects in a window having an edge surface and a planar surface. The method is comprised of steps for mounting the window on a support surface. Then a light sensitive paper is placed adjacent to the window surface. A light source is positioned adjacent to the window edge. The window is then illuminated with the source of light for a predetermined interval of time. Defects on the surface of the glass, as well as in the interior of the glass are detected by analyzing the developed light sensitive paper. The light source must be in the form of optical fibers or a light tube whose light transmitting ends are placed near the edge surface of the window.

  2. Optics near a hyperbolic defect

    NASA Astrophysics Data System (ADS)

    Fumeron, Sébastien; Berche, Bertrand; Santos, Fernando; Pereira, Erms; Moraes, Fernando

    2015-12-01

    We examine the properties of a family of defects called hyperbolic disclinations, and discuss their possible use for the design of perfect optical absorbers. In hyperbolic metamaterials, the ratio of ordinary and extraordinary permittivities is negative, which leads to an effective metric of Kleinian signature (two timelike coordinates). Considering a disclination in the hyperbolic nematic host matrix, we show that the timelike geodesics are Poinsot spirals, i.e., whatever the impact parameter of an incident light beam, it is confined and whirls about the defect core. The trapping effect does not require light to be coherent. This property also remains in the wave formalism, which may be the sign for many potential applications.

  3. Cooperation and Defection in Ghetto

    NASA Astrophysics Data System (ADS)

    Kułakowski, Krzysztof

    We consider ghetto as a community of people ruled against their will by an external power. Members of the community feel that their laws are broken. However, attempts to leave ghetto makes their situation worse. We discuss the relation of the ghetto inhabitants to the ruling power in context of their needs, organized according to the Maslow hierarchy. Decisions how to satisfy successive needs are undertaken in cooperation with or defection the ruling power. This issue allows to construct the tree of decisions and to adopt the pruning technique from the game theory. Dynamics of decisions can be described within the formalism of fundamental equations. The result is that the strategy of defection is stabilized by the estimated payoff.

  4. Structural defects in crystalline silicon

    NASA Technical Reports Server (NTRS)

    Sirtl, E.

    1985-01-01

    The basic photovoltaic properties of a given crystalline silicon specimen seem to be governed by density and nature of two to three dimensional lattice defects. These are mainly generated by primary growth conditions as grain boundaries of more or less intrinsic character or second phase precipitates from supersaturated solutions of carbon or oxygen. Considerably high values of both solubility and diffusivity in connection with their abundance in common refractory material systems account for the predominance of the two particular elements. Unsaturated dislocations of different types very often can be seen as a consequence of the existence of more dimensional defects as described initially. The final performance of a solar cell is dependent of the concentration and distribution of recombination active centers in the different regions of this device. Typical representatives are fast diffusing transition metals in form of either single atoms or simple complexes. Their avoidance, annihilation, or removal is of great concern in different fields of electronic materials development.

  5. Endotracheal Tube Obstruction: A Manufacturing Defect.

    PubMed

    Baldemir, Ramazan; Akçaboy, Yavuz; Akçaboy, Zeynep Nur; Göğüş, Nermin

    2015-02-01

    Various manufacturing defects of endotracheal tubes are encountered in anaesthesia practice. One of the important defects of an endotracheal tube is that a partial or complete obstruction can be potentially life-threatening. Manufacturing defects may not be ascertainable by routine inspection. In this case report, we report a partial airway obstruction caused by a plastic membrane in the connector of an endotracheal tube as a manufacturing defect. PMID:27366468

  6. COMPARISON OF SELECTED WELD DEFECT EXTRACTION METHODS

    SciTech Connect

    Sikora, R.; Baniukiewicz, P.; Chady, T.; Rucinski, W.; Swiadek, K.; Caryk, M.; Lopato, P.

    2008-02-28

    This paper presents three different methods of welding defects detection from radiographs. First two methods are dedicated for extraction of flaws directly from radiograms. Fuzzy logic system considers whether the pixel belongs to crack (or background) using defects probability maps together with simple fuzzy rules. Neural network method uses knowledge gathered from radiographs with known defects. Indirect method extracts defects by subtracting background from the radiograph and next using various local thresholding methods.

  7. Inspection of lithographic mask blanks for defects

    DOEpatents

    Sommargren, Gary E.

    2001-01-01

    A visible light method for detecting sub-100 nm size defects on mask blanks used for lithography. By using optical heterodyne techniques, detection of the scattered light can be significantly enhanced as compared to standard intensity detection methods. The invention is useful in the inspection of super-polished surfaces for isolated surface defects or particulate contamination and in the inspection of lithographic mask or reticle blanks for surface defects or bulk defects or for surface particulate contamination.

  8. Decay of metastable topological defects

    SciTech Connect

    Preskill, J. ); Vilenkin, A. Lyman Laboratory of Physics, Harvard University, Cambridge, Massachusetts 02138 )

    1993-03-15

    We systematically analyze the decay of metastable topological defects that arise from the spontaneous breakdown of gauge or global symmetries. Quantum-mechanical tunneling rates are estimated for a variety of decay processes. The decay rate for a global string, vortex, domain wall, or kink is typically suppressed compared to the decay rate for its gauged counterpart. We also discuss the decay of global texture, and of semilocal and electroweak strings.

  9. Visual field defects in onchocerciasis.

    PubMed Central

    Thylefors, B; Tønjum, A M

    1978-01-01

    Lesions in the posterior segment of the eye in onchocerciasis may give visual field defects, but so far no detailed investigation has been done to determine the functional visual loss. Examination of the visual fields in 18 selected cases of onchocerciasis by means of a tangent screen test revealed important visual field defects associated with lesions in the posterior segment of the eye. Involvement of the optic nerve seemed to be important, giving rise to severely constricted visual fields. Cases of postneuritic optic atrophy showed a very uniform pattern of almost completely constricted visual fields, with only 5 to 10 degree central rest spared. Papillitis gave a similar severe constriction of the visual fields. The pattern of visual fields associated with optic neuropathy in onchocerciasis indicates that a progressive lesion of the optic nerve from the periphery may be responsible for the loss of vision. The visual field defects in onchocerciasis constitute a serious handicap, which must be taken into consideration when estimating the socioeconomic importance of the disease. Images PMID:678499

  10. 30 CFR 57.7002 - Equipment defects.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Equipment defects. 57.7002 Section 57.7002... Jet Piercing Drilling-Surface Only § 57.7002 Equipment defects. Equipment defects affecting safety shall be corrected before the equipment is used....

  11. Method for mask repair using defect compensation

    DOEpatents

    Sweeney, Donald W.; Ray-Chaudhuri, Avijit K.

    2001-01-01

    A method for repair of amplitude and/or phase defects in lithographic masks. The method involves modifying or altering a portion of the absorber pattern on the surface of the mask blank proximate to the mask defect to compensate for the local disturbance (amplitude or phase) of the optical field due to the defect.

  12. Templates Aid Removal Of Defects From Castings

    NASA Technical Reports Server (NTRS)

    Hendrickson, Robert G.

    1992-01-01

    Templates used to correlate defects in castings with local wall thicknesses. Placed on part to be inspected after coated with penetrant dye. Positions of colored spots (indicative of defects) noted. Ultrasonic inspector measures thickness of wall at unacceptable defects only - overall inspection not necessary.

  13. 7 CFR 51.2659 - Condition defects.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Condition defects. 51.2659 Section 51.2659 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Standards for Grades for Sweet Cherries 1 Definitions § 51.2659 Condition defects. Condition defects...

  14. The bilobed flap for popliteal defect reconstruction

    PubMed Central

    Kelahmetoglu, Osman; Yagmur, Caglayan; Aslan, Ozan; Firinciogullari, Remzi

    2014-01-01

    Abstract Bilobed flaps were first introduced to close small nasal defects. We reconstructed a defect of the popliteal fossa using a random-pattern bilobed flap. We recommend the use of random-pattern bilobed flaps as a reliable technique for covering defects of the popliteal fossa.

  15. Second workshop role of point defects/defect complexes in silicon device fabrication

    SciTech Connect

    Not Available

    1992-01-01

    Abstracts are presented of 24 papers, arranged under the following session/panel headings: defects and impurities in commercial photovoltaic Si substrates, point defects and point defect processes, impurity gettering for Si solar cells, gettering in Si solar cells, and passivation of impurities and defects.

  16. Effects of Stone-Wales and vacancy defects in atomic-scale friction on defective graphite

    SciTech Connect

    Sun, Xiao-Yu; Wu, RunNi; Xia, Re; Chu, Xi-Hua; Xu, Yuan-Jie

    2014-05-05

    Graphite is an excellent solid lubricant for surface coating, but its performance is significantly weakened by the vacancy or Stone-Wales (SW) defect. This study uses molecular dynamics simulations to explore the frictional behavior of a diamond tip sliding over a graphite which contains a single defect or stacked defects. Our results suggest that the friction on defective graphite shows a strong dependence on defect location and type. The 5-7-7-5 structure of SW defect results in an effectively negative slope of friction. For defective graphite containing a defect in the surface, adding a single vacancy in the interior layer will decrease the friction coefficients, while setting a SW defect in the interior layer may increase the friction coefficients. Our obtained results may provide useful information for understanding the atomic-scale friction properties of defective graphite.

  17. Computational stoning method for surface defect detection

    NASA Astrophysics Data System (ADS)

    Ma, Ninshu; Zhu, Xinhai

    2013-12-01

    Surface defects on outer panels of automotive bodies must be controlled in order to improve the surface quality. The detection and quantitative evaluation of surface defects are quite difficult because the deflection of surface defects is very small. One of detecting methods for surface defects used in factories is a stoning method in which a stone block is moved on the surface of a stamped panel. The computational stoning method was developed to detect surface low defect by authors based on a geometry contact algorithm between a stone block and a stamped panel. If the surface is convex, the stone block always contacts with the convex surface of a stamped panel and the contact gap between them is zero. If there is a surface low, the stone block does not contact to the surface and the contact gap can be computed based on contact algorithm. The convex surface defect can also be detected by applying computational stoning method to the back surface of a stamped panel. By performing two way stoning computations from both the normal surface and the back surface, not only the depth of surface low defect but also the height of convex surface defect can be detected. The surface low defect and convex surface defect can also be detected through multi-directions. Surface defects on the handle emboss of outer panels were accurately detected using the computational stoning method and compared with the real shape. A very good accuracy was obtained.

  18. Selecting the best defect reduction methodology

    SciTech Connect

    Hinckley, C.M.; Barkan, P.

    1994-04-01

    Defect rates less than 10 parts per million, unimaginable a few years ago, have become the standard of world-class quality. To reduce defects, companies are aggressively implementing various quality methodologies, such as Statistical Quality Control Motorola`s Six Sigma, or Shingo`s poka-yok. Although each quality methodology reduces defects, selection has been based on an intuitive sense without understanding their relative effectiveness in each application. A missing link in developing superior defect reduction strategies has been a lack of a general defect model that clarifies the unique focus of each method. Toward the goal of efficient defect reduction, we have developed an event tree which addresses a broad spectrum of quality factors and two defect sources, namely, error and variation. The Quality Control Tree (QCT) predictions are more consistent with production experience than obtained by the other methodologies considered independently. The QCT demonstrates that world-class defect rates cannot be achieved through focusing on a single defect source or quality control factor, a common weakness of many methodologies. We have shown that the most efficient defect reduction strategy depend on the relative strengths and weaknesses of each organization. The QCT can help each organization identify the most promising defect reduction opportunities for achieving its goals.

  19. Resist process optimization for further defect reduction

    NASA Astrophysics Data System (ADS)

    Tanaka, Keiichi; Iseki, Tomohiro; Marumoto, Hiroshi; Takayanagi, Koji; Yoshida, Yuichi; Uemura, Ryouichi; Yoshihara, Kosuke

    2012-03-01

    Defect reduction has become one of the most important technical challenges in device mass-production. Knowing that resist processing on a clean track strongly impacts defect formation in many cases, we have been trying to improve the track process to enhance customer yield. For example, residual type defect and pattern collapse are strongly related to process parameters in developer, and we have reported new develop and rinse methods in the previous papers. Also, we have reported the optimization method of filtration condition to reduce bridge type defects, which are mainly caused by foreign substances such as gels in resist. Even though we have contributed resist caused defect reduction in past studies, defect reduction requirements continue to be very important. In this paper, we will introduce further process improvements in terms of resist defect reduction, including the latest experimental data.

  20. Yield impacting systematic defects search and management

    NASA Astrophysics Data System (ADS)

    Zhang, Jing; Xu, Qingxiu; Zhang, Xin; Zhao, Xing; Ning, Jay; Cheng, Guojie; Chen, Shijie; Zhang, Gary; Vikram, Abhishek; Su, Bo

    2012-03-01

    Despite great effort before design tapeout, there are still some pattern related systematic defects showing up in production, which impact product yield. Through various check points in the production life cycle endeavor is made to detect these defective patterns. It is seen that apart from the known defective patterns, slight variations of polygon sizes and shapes in the known defective patterns also cause yield loss. This complexity is further compounded when interactions among multiple process layers causes the defect. Normally the exact pattern matching techniques cannot detect these variations of the defective patterns. With the currently existing tools in the fab it is a challenge to define the 'sensitive patterns', which are arbitrary variations in the known 'defective patterns'. A design based approach has been successfully experimented on product wafers to detect yield impacting defects that greatly reduces the TAT for hotspot analysis and also provides optimized care area definition to enable high sensitivity wafer inspection. A novel Rule based pattern search technique developed by Anchor Semiconductor has been used to find sensitive patterns in the full chip design. This technique allows GUI based pattern search rule generation like, edge move or edge-to-edge distance range, so that any variations of a particular sensitive pattern can be captured and flagged. Especially the pattern rules involving multiple process layers, like M1-V1-M2, can be defined easily using this technique. Apart from using this novel pattern search technique, design signatures are also extracted around the defect locations in the wafer and used in defect classification. This enhanced defect classification greatly helps in determining most critical defects among the total defect population. The effectiveness of this technique has been established through design to defect correlation and SEM verification. In this paper we will report details of the design based experiments that

  1. If Your Child Has a Heart Defect (For Parents)

    MedlinePlus

    ... septal defect , atrial septal defect , atrioventricular canal, and patent ductus arteriosus). Or the congestion could be the ... for Congenital Heart Defects Many heart abnormalities (including patent ductus arteriosus , ventricular septal defect , truncus arteriosus, atrioventricular ...

  2. Facts about Upper and Lower Limb Reduction Defects

    MedlinePlus

    ... Specific Birth Defects Anencephaly Anophthalmia/Microphthalmia Anotia/Microtia Cleft Lip / Cleft Palate Congenital Heart Defects Atrial Septal Defect ... Podcasts & Video E-Cards Flu Badge Real Stories Cleft Lip and Palate Craniosynostosis Down Syndrome Eye Defects Fetal ...

  3. Advanced defect and metrology solutions

    NASA Astrophysics Data System (ADS)

    Novak, Erik

    2014-05-01

    Cost, weight, performance, and lifetime requirements for precision components used throughout the aerospace and defense industries are driving innovative mechanical designs, manufacturing processes and use of new materials. In turn, these advanced components typically require tighter dimensional and surface tolerances to function as designed. Scratch testers, microscope-based systems, and other traditional metrology systems are inadequate for roughness, small-scale geometry, and defect determination on many of these parts. This talk will examine the advantages and disadvantages of some of the new technologies developed to provide more robust, versatile, and sensitive measurements of precision components for advanced manufacturing environments.

  4. Improvement in accuracy of defect size measurement by automatic defect classification

    NASA Astrophysics Data System (ADS)

    Samir, Bhamidipati; Pereira, Mark; Paninjath, Sankaranarayanan; Jeon, Chan-Uk; Chung, Dong-Hoon; Yoon, Gi-Sung; Jung, Hong-Yul

    2015-10-01

    The blank mask defect review process involves detailed analysis of defects observed across a substrate's multiple preparation stages, such as cleaning and resist-coating. The detailed knowledge of these defects plays an important role in the eventual yield obtained by using the blank. Defect knowledge predominantly comprises of details such as the number of defects observed, and their accurate sizes. Mask usability assessment at the start of the preparation process, is crudely based on number of defects. Similarly, defect size gives an idea of eventual wafer defect printability. Furthermore, monitoring defect characteristics, specifically size and shape, aids in obtaining process related information such as cleaning or coating process efficiencies. Blank mask defect review process is largely manual in nature. However, the large number of defects, observed for latest technology nodes with reducing half-pitch sizes; and the associated amount of information, together make the process increasingly inefficient in terms of review time, accuracy and consistency. The usage of additional tools such as CDSEM may be required to further aid the review process resulting in increasing costs. Calibre® MDPAutoClassify™ provides an automated software alternative, in the form of a powerful analysis tool for fast, accurate, consistent and automatic classification of blank defects. Elaborate post-processing algorithms are applied on defect images generated by inspection machines, to extract and report significant defect information such as defect size, affecting defect printability and mask usability. The algorithm's capabilities are challenged by the variety and complexity of defects encountered, in terms of defect nature, size, shape and composition; and the optical phenomena occurring around the defect [1]. This paper mainly focuses on the results from the evaluation of Calibre® MDPAutoClassify™ product. The main objective of this evaluation is to assess the capability of

  5. Analyzing the impact of ISO on digital imager defects with an automatic defect trace algorithm

    NASA Astrophysics Data System (ADS)

    Leung, Jenny; Chapman, Glenn H.; Choi, Yong H.; Thomas, Rohit; Koren, Israel; Koren, Zahava

    2010-01-01

    Reliability of image sensors is limited by the continuous development of in-field defects. Laboratory calibration on 21 DSLRs has revealed hot pixels as the main defect type found in all tested cameras, with 78% of the identified defects having a time-independent offset. The expanded ISO range that exists in new cameras enables natural light photography. However, the gain applied to all pixels also enhances the appearance of defects. Analysis of defects at varying ISO levels shows that compared to the number of defects at ISO 400, the number of defects at ISO 1600 is 2-3 times higher. Amplifying the defect parameters helps differentiate faults from noise, thus detecting larger defect sets and causes some hot pixels to become saturated. The distribution of defect parameters at various ISO levels shows that the gain applied to faults with moderate defect magnitude caused 2-10% of the defects to saturate at short exposure times (0.03-0.5s). With our expanded defect collection, spatial analysis confirmed the uniform distribution of defects, indicating a random defect source. In our extended study, the temporal growth of defects is analyzed using our defecttracing algorithm. We introduce an improved defect model which incorporates the ISO gain, allowing the detection of defects even in short exposure images at high ISO and thus providing a wider selection of historical images and more accurate defect tracing. Larger area sensors show more hot pixels, while hot pixel rates strongly grow as the pixel size decreases to 2.2 microns.

  6. Molecularly Tunable Fluorescent Quantum Defects.

    PubMed

    Kwon, Hyejin; Furmanchuk, Al'ona; Kim, Mijin; Meany, Brendan; Guo, Yong; Schatz, George C; Wang, YuHuang

    2016-06-01

    We describe the chemical creation of molecularly tunable fluorescent quantum defects in semiconducting carbon nanotubes through covalently bonded surface functional groups that are themselves nonemitting. By variation of the surface functional groups, the same carbon nanotube crystal is chemically converted to create more than 30 distinct fluorescent nanostructures with unique near-infrared photoluminescence that is molecularly specific, systematically tunable, and significantly brighter than that of the parent semiconductor. This novel exciton-tailoring chemistry readily occurs in aqueous solution and creates functional defects on the sp(2) carbon lattice with highly predictable C-C bonding from virtually any iodine-containing hydrocarbon precursor. Our new ability to control nanostructure excitons through a single surface functional group opens up exciting possibilities for postsynthesis chemical engineering of carbon nanomaterials and suggests that the rational design and creation of a large variety of molecularly tunable quantum emitters-for applications ranging from in vivo bioimaging and chemical sensing to room-temperature single-photon sources-can now be anticipated. PMID:27159413

  7. Gravitational energy of conical defects

    SciTech Connect

    Maluf, J.W.; Kneip, A.

    1997-01-01

    The energy density {epsilon}{sub g} of asymptotically flat gravitational fields can be calculated from a simple expression involving the trace of the torsion tensor. The integral of this energy density over the whole space yields the Arnowitt{endash}Deser{endash}Misner (ADM) energy. Such energy expression can be justified within the framework of the teleparallel equivalent of general relativity, which is an alternative geometrical formulation of Einstein{close_quote}s general relativity. In this paper we apply {epsilon}{sub g} to the evaluation of the energy per unit length of a class of conical defects of topological nature, which include disclinations and dislocations (in the terminology of crystallography). Disclinations correspond to cosmic strings, and for a space{endash}time endowed with only such a defect the well known expression of energy per unit length is obtained precisely. However for a pure space{endash}time dislocation the total gravitational energy is zero. {copyright} {ital 1997 American Institute of Physics.}

  8. Effects of in-cascade defect clustering on near-term defect evolution

    SciTech Connect

    Heinisch, H.L.

    1997-08-01

    The effects of in-cascade defect clustering on the nature of the subsequent defect population are being studied using stochastic annealing simulations applied to cascades generated in molecular dynamics (MD) simulations. The results of the simulations illustrates the strong influence of the defect configuration existing in the primary damage state on subsequent defect evolution. The large differences in mobility and stability of vacancy and interstitial defects and the rapid one-dimensional diffusion of small, glissile interstitial loops produced directly in cascades have been shown to be significant factors affecting the evolution of the defect distribution. In recent work, the effects of initial cluster sizes appear to be extremely important.

  9. Altering graphene line defect properties using chemistry

    NASA Astrophysics Data System (ADS)

    Vasudevan, Smitha; White, Carter; Gunlycke, Daniel

    2012-02-01

    First-principles calculations are presented of a fundamental topological line defect in graphene that was observed and reported in Nature Nanotech. 5, 326 (2010). These calculations show that atoms and smaller molecules can bind covalently to the surface in the vicinity of the graphene line defect. It is also shown that the chemistry at the line defect has a strong effect on its electronic and magnetic properties, e.g. the ferromagnetically aligned moments along the line defect can be quenched by some adsorbates. The strong effect of the adsorbates on the line defect properties can be understood by examining how these adsorbates affect the boundary-localized states in the vicinity of the Fermi level. We also expect that the line defect chemistry will significantly affect the scattering properties of incident low-energy particles approaching it from graphene.

  10. Defect-Engineered Metal–Organic Frameworks

    PubMed Central

    Fang, Zhenlan; Bueken, Bart; De Vos, Dirk E; Fischer, Roland A

    2015-01-01

    Defect engineering in metal–organic frameworks (MOFs) is an exciting concept for tailoring material properties, which opens up novel opportunities not only in sorption and catalysis, but also in controlling more challenging physical characteristics such as band gap as well as magnetic and electrical/conductive properties. It is challenging to structurally characterize the inherent or intentionally created defects of various types, and there have so far been few efforts to comprehensively discuss these issues. Based on selected reports spanning the last decades, this Review closes that gap by providing both a concise overview of defects in MOFs, or more broadly coordination network compounds (CNCs), including their classification and characterization, together with the (potential) applications of defective CNCs/MOFs. Moreover, we will highlight important aspects of “defect-engineering” concepts applied for CNCs, also in comparison with relevant solid materials such as zeolites or COFs. Finally, we discuss the future potential of defect-engineered CNCs. PMID:26036179

  11. Atomic Defects in Two Dimensional Materials.

    PubMed

    Rasool, Haider I; Ophus, Colin; Zettl, Alex

    2015-10-14

    Atomic defects in crystalline structures have pronounced affects on their bulk properties. Aberration-corrected transmission electron microscopy has proved to be a powerful characterization tool for understanding the bonding structure of defects in materials. In this article, recent results on the characterization of defect structures in two dimensional materials are discussed. The dynamic behavior of defects in graphene shows the stability of zigzag edges of the material and gives insights into the dislocation motion. Polycrystalline graphene is characterized using advanced electron microscopy techniques, revealing the global crystal structure of the material, as well as atomic-resolution observation of the carbon atom positions between neighboring crystal grains. Studies of hexagonal boron nitride (hBN) are also visited, highlighting the interlayer bonding, which occurs upon defect formation, and characterization of grain boundary structures. Lastly, defect structures in monolayer polycrystalline transition metal dichalcogenides grown by CVD are discussed. PMID:25946075

  12. Semiconductor yield improvements through automatic defect classification

    SciTech Connect

    Gleason, S.; Kulkarni, A.

    1995-09-30

    Automatic detection of defects during the fabrication of semiconductor wafers is largely automated, but the classification of those defects is still performed manually by technicians. Projections by semiconductor manufacturers predict that with larger wafer sizes and smaller line width technology the number of defects to be manually classified will increase exponentially. This cooperative research and development agreement (CRADA) between Martin Marietta Energy Systems (MMES) and KLA Instruments developed concepts, algorithms and systems to automate the classification of wafer defects to decrease inspection time, improve the reliability of defect classification, and hence increase process throughput and yield. Image analysis, feature extraction, pattern recognition and classification schemes were developed that are now being used as research tools for future products and are being integrated into the KLA line of wafer inspection hardware. An automatic defect classification software research tool was developed and delivered to the CRADA partner to facilitate continuation of this research beyond the end of the partnership.

  13. Agricultural Compounds in Water and Birth Defects.

    PubMed

    Brender, Jean D; Weyer, Peter J

    2016-06-01

    Agricultural compounds have been detected in drinking water, some of which are teratogens in animal models. The most commonly detected agricultural compounds in drinking water include nitrate, atrazine, and desethylatrazine. Arsenic can also be an agricultural contaminant, although arsenic often originates from geologic sources. Nitrate has been the most studied agricultural compound in relation to prenatal exposure and birth defects. In several case-control studies published since 2000, women giving birth to babies with neural tube defects, oral clefts, and limb deficiencies were more likely than control mothers to be exposed to higher concentrations of drinking water nitrate during pregnancy. Higher concentrations of atrazine in drinking water have been associated with abdominal defects, gastroschisis, and other defects. Elevated arsenic in drinking water has also been associated with birth defects. Since these compounds often occur as mixtures, it is suggested that future research focus on the impact of mixtures, such as nitrate and atrazine, on birth defects. PMID:27007730

  14. Perception of risk from automobile safety defects.

    PubMed

    Slovic, P; MacGregor, D; Kraus, N N

    1987-10-01

    Descriptions of safety engineering defects of the kind that compel automobile manufacturers to initiate a recall campaign were evaluated by individuals on a set of risk characteristic scales that included overall vehicle riskiness, manufacturer's ability to anticipate the defect, importance for vehicle operation, severity of consequences and likelihood of compliance with a recall notice. A factor analysis of the risk characteristics indicated that judgments could be summarized in terms of two composite scales, one representing the uncontrollability of the damage the safety defect might cause and the other representing the foreseeability of the defect by the manufacturer. Motor vehicle defects were found to be highly diverse in terms of the perceived qualities of their risks. Location of individual defects within the factor space was closely associated with perceived riskiness, perceived likelihood of purchasing another car from the same manufacturer, perceived likelihood of compliance with a recall notice, and actual compliance rates. PMID:3675807

  15. Wafer Mapping Using Deuterium Enhanced Defect Characterization

    NASA Astrophysics Data System (ADS)

    Hossain, K.; Holland, O. W.; Hellmer, R.; Vanmil, B.; Bubulac, L. O.; Golding, T. D.

    2010-07-01

    Deuterium (as well as other hydrogen isotopes) binds with a wide range of morphological defects in semiconductors and, as such, becomes distributed similarly to those defects. Thus, the deuterium profile within the sample serves as the basis of a technique for defect mapping known as amethyst wafer mapping (AWM). The efficiency of this technique has been demonstrated by evaluation of ion-induced damage in implanted Si, as well as as-grown defects in HgCdTe (MCT) epilayers. The defect tagging or decoration capability of deuterium is largely material independent and applicable to a wide range of defect morphologies. A number of analytical techniques including ion channeling and etch pit density measurements were used to evaluate the AWM results.

  16. Pinning of flux lines by planar defects

    NASA Astrophysics Data System (ADS)

    Petković, Aleksandra; Emig, Thorsten; Nattermann, Thomas

    2009-06-01

    The influence of randomly distributed point impurities and planar defects on order and transport in type-II superconductors and related systems is studied. It is shown that the Bragg glass phase is unstable with respect to planar defects. Even a single weak defect plane oriented parallel to the magnetic field as well as to one of the main axes of the Abrikosov flux-line lattice is a relevant perturbation in the Bragg glass. A defect that is aligned with the magnetic field restores the flux density oscillations, which decay algebraically with the distance from the defect. The theory exhibits striking similarities to the physics of a Luttinger liquid with a frozen impurity. The exponent for the flux-line creep in the direction perpendicular to a relevant defect is derived. We find that the flux-line lattice exhibits in the presence of many randomly distributed parallel planar defects aligned to the magnetic field a glassy phase which we call planar glass. The planar glass is characterized by diverging shear and tilt moduli, a transverse Meissner effect, and resistance against shear deformations. We also obtain sample-to-sample fluctuations of the longitudinal magnetic susceptibility and an exponential decay of translational long-range order in the direction perpendicular to the defects. The flux creep perpendicular to the defects leads to a nonlinear resistivity ρ(J→0)˜exp[-(JD/J)3/2] . Strong planar defects enforce arrays of dislocations that are located at the defects with a Burgers vector parallel to the defects in order to relax shear strain.

  17. Processed-induced defects in EFG ribbons

    NASA Technical Reports Server (NTRS)

    Cunningham, B.; Ast, D. G.

    1982-01-01

    The defect structure of processed edge defined film-fed growth (EFG) silicon ribbons was studied using a variety of electron microscopic techniques. Comparison between the present results and previous studies on as-grown ribbons has shown that solar cell processing introduces additional defects into the ribbons. The creation of point defects during high temperature phosphorus diffusion induces dislocation climb, resulting in the formation of dislocation helices in the diffused layer.

  18. Detection of tanker defects with infrared thermography

    NASA Technical Reports Server (NTRS)

    Kantsios, A. G.

    1980-01-01

    Infrared scanning technique for finding defects in secondary barrier of liquid natural gas (LNG) tank has been successfully tested on ship under construction at Newport News Shipbuilding and Dry Dock Company. Technique determines defects with minimal expenditure of time and manpower. Tests could be repeated during life of tanker and make more complicated testing unnecessary. Tests also confirmed that tank did not have any major defects, and tank was certified.

  19. Research In Diagnosing Bearing Defects From Vibrations

    NASA Technical Reports Server (NTRS)

    Zoladz, T.; Earhart, E.; Fiorucci, T.

    1995-01-01

    Report describes research in bearing-defect signature analysis - use of vibration-signal analysis to diagnose defects in roller and ball bearings. Experiments performed on bearings in good condition and other bearings in which various parts scratched to provide known defects correlated with vibration signals. Experiments performed on highly instrumented motor-driven rotor assembly at speeds up to 10,050 r/min, using accelerometers, velocity probes, and proximity sensors mounted at various locations on assembly to measure vibrations.

  20. Multimode model based defect characterization in composites

    NASA Astrophysics Data System (ADS)

    Roberts, R.; Holland, S.; Gregory, E.

    2016-02-01

    A newly-initiated research program for model-based defect characterization in CFRP composites is summarized. The work utilizes computational models of the interaction of NDE probing energy fields (ultrasound and thermography), to determine 1) the measured signal dependence on material and defect properties (forward problem), and 2) an assessment of performance-critical defect properties from analysis of measured NDE signals (inverse problem). Work is reported on model implementation for inspection of CFRP laminates containing delamination and porosity. Forward predictions of measurement response are presented, as well as examples of model-based inversion of measured data for the estimation of defect parameters.

  1. Screening for Open Neural Tube Defects.

    PubMed

    Krantz, David A; Hallahan, Terrence W; Carmichael, Jonathan B

    2016-06-01

    Biochemical prenatal screening was initiated with the use of maternal serum alpha fetoprotein to screen for open neural tube defects. Screening now includes multiple marker and sequential screening protocols involving serum and ultrasound markers to screen for aneuploidy. Recently cell-free DNA screening for aneuploidy has been initiated, but does not screen for neural tube defects. Although ultrasound is highly effective in identifying neural tube defects in high-risk populations, in decentralized health systems maternal serum screening still plays a significant role. Abnormal maternal serum alpha fetoprotein alone or in combination with other markers may indicate adverse pregnancy outcome in the absence of open neural tube defects. PMID:27235920

  2. Defect interactions within a group of subcascades

    SciTech Connect

    Heinisch, H.L.

    1996-10-01

    The evolution of the defect distributions within high energy cascades that contain multiple subcascades is studied as a function of temperature for cascades in copper. Low energy cascades generated with molecular dynamics are placed in close proximity to simulate the arrangement of subcascades within a high energy event, then the ALSOME code follows the evolution of the cascade damage during short term annealing. The intersubcascade defect interactions during the annealing stage are found to be minimal. However, no conclusions regarding effects of subcascades on defect production should be drawn until intersubcascade defect interactions during the quenching stage are examined.

  3. Energy Barriers for Defects in Disordered Solids

    NASA Astrophysics Data System (ADS)

    Wijtmans, Sven; Manning, Lisa

    2015-03-01

    In solids, defects govern flow and failure. In crystals, defects are easily-identified dislocations, while in disordered solids, defects can be found by analyzing the vibrational modes of the system, which are eigenvectors of the matrix describing the linear response. The low frequency modes are typically quasi-localized hybrids of excitations localized at the defects and plane-wave like modes. Additional analysis can separate these components, giving the location of a defect and displacement of particles along that defect. To define an energy barrier for each defect, we displace particles along an isolated defect mode and calculate the energy at which the system transitions to a new energy basin. Different definitions of a new basin, such as a change in the particle contact network or particle displacements above a specific threshold, give different results. We identify several criteria that are consistent and provide a reasonable, robust definition of an energy barrier. Somewhat surprisingly, we find that energy barriers for isolated defects are generally higher than energy barriers for typical quasi-localized modes in the system.

  4. Electricity generation from defective tomatoes.

    PubMed

    Shrestha, Namita; Fogg, Alex; Wilder, Joseph; Franco, Daniel; Komisar, Simeon; Gadhamshetty, Venkataramana

    2016-12-01

    The United States faces a significant burden in treating 0.61billionkg of defective tomatoes (culls) every year. We present a proof-of-concept for generating electricity from culled tomatoes in microbial-electrochemical systems (MESs). This study delineates impedance behavior of the culled tomatoes in MESs and compares its impedance spectra with that of soluble substrates (dextrose, acetate, and wastewater). A series of AC and DC diagnostic tests have revealed the superior performance of the culled tomatoes compared to the pure substrates. Cyclic voltammetry results have indicated the active role of indigenous, diffusible redox-active pigments in the culled tomatoes on overall electricity production. Electrochemical impedance spectroscopy results have elucidated the role of peel and seed on the oxidation behavior of the culled tomatoes. PMID:27474917

  5. Defect reduction through Lean methodology

    NASA Astrophysics Data System (ADS)

    Purdy, Kathleen; Kindt, Louis; Densmore, Jim; Benson, Craig; Zhou, Nancy; Leonard, John; Whiteside, Cynthia; Nolan, Robert; Shanks, David

    2010-09-01

    Lean manufacturing is a systematic method of identifying and eliminating waste. Use of Lean manufacturing techniques at the IBM photomask manufacturing facility has increased efficiency and productivity of the photomask process. Tools, such as, value stream mapping, 5S and structured problem solving are widely used today. In this paper we describe a step-by-step Lean technique used to systematically decrease defects resulting in reduced material costs, inspection costs and cycle time. The method used consists of an 8-step approach commonly referred to as the 8D problem solving process. This process allowed us to identify both prominent issues as well as more subtle problems requiring in depth investigation. The methodology used is flexible and can be applied to numerous situations. Advantages to Lean methodology are also discussed.

  6. SEMATECH produces defect-free EUV mask blanks: defect yield and immediate challenges

    NASA Astrophysics Data System (ADS)

    Antohe, Alin O.; Balachandran, Dave; He, Long; Kearney, Patrick; Karumuri, Anil; Goodwin, Frank; Cummings, Kevin

    2015-03-01

    Availability of defect-free reflective mask has been one of the most critical challenges to extreme ultraviolet lithography (EUVL). To mitigate the risk, significant progress has been made on defect detection, pattern shifting, and defect repair. Clearly such mitigation strategies are based on the assumption that defect counts and sizes from incoming mask blanks must be below practical levels depending on mask specifics. The leading industry consensus for early mask product development is that there should be no defects greater than 80 nm in the quality area, 132 mm x 132 mm. In addition less than 10 defects smaller than 80 nm may be mitigable. SEMATECH has been focused on EUV mask blank defect reduction using Veeco Nexus TM IBD platform, the industry standard for mask blank production, and assessing if IBD technology can be evolved to a manufacturing solution. SEMATECH has recently announced a breakthrough reduction of defects in the mask blank deposition process resulting in the production of two defect-free EUV mask blanks at 54 nm inspection sensitivity (SiO2 equivalent). This paper will discuss the dramatic reduction of baseline EUV mask blank defects, review the current deposition process run and compare results with previous process runs. Likely causes of remaining defects will be discussed based on analyses as characterized by their compositions and whether defects are embedded in the multilayer stack or non-embedded.

  7. Quantum defect analysis of HD photoionization

    SciTech Connect

    Du, N.Y.; Greene, C.H.

    1986-11-15

    A multichannel quantum defect calculation is shown to reproduce most observed features in several portions of the HD photoabsorption spectrum. The rovibrational frame transformation theory of Atabek, Dill, and Jungen is reformulated in terms of a quantum defect matrix. The calculation accounts for spectral regions far from dissociation thresholds despite its neglect of g--u mixing.

  8. First principles calculations for defects in U

    SciTech Connect

    B. Beeler; B. Good; S. Rashkeev; C. Deo; M. Baskes; M. Okuniewski

    2010-12-01

    Uranium (U) exhibits a high temperature body-centered cubic (bcc) allotrope that is often stabilized by alloying with transition metals such as Zr, Mo, and Nb for technological applications. One such application involves U–Zr as nuclear fuel, where radiation damage and diffusion (processes heavily dependent on point defects) are of vital importance. Several systems of U are examined within a density functional theory framework utilizing projector augmented wave pseudopotentials. Two separate generalized gradient approximations of the exchange-correlation are used to calculate defect properties and are compared. The bulk modulus, the lattice constant, and the Birch–Murnaghan equation of state for the defect free bcc uranium allotrope are calculated. Defect parameters calculated include energies of formation of vacancies in the a and ? allotropes, as well as self-interstitials, Zr interstitials, and Zr substitutional defects for the ? allotrope. The results for vacancies agree very well with experimental and previous computational studies. The most probable self-interstitial site in ?-U is the 110 dumbbell, and the most probable defect location for dilute Zr in ?-U is the substitutional site. This is the first detailed study of self-defects in the bcc allotrope of U and also the first comprehensive study of dilute Zr defects in ?-U.

  9. Biomaterials for reconstruction of cranial defects

    NASA Astrophysics Data System (ADS)

    Song, Tao; Qiu, Zhi-Ye; Cui, Fu-Zhai

    2015-12-01

    Reconstruction of cranial defect is commonly performed in neurosurgical operations. Many materials have been employed for repairing cranial defects. In this paper, materials used for cranioplasty, including autografts, allografts, and synthetic biomaterials are comprehensively reviewed. This paper also gives future perspective of the materials and development trend of manufacturing process for cranioplasty implants.

  10. Stem-end chip defect update

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stem-end chip defect is characterized by dark fried color along the vasculature and adjacent tissues at a position in the chip that corresponds to the tuber stem end. Stem-end chip defect occurs erratically over years and locations. In some years and in some regions, it can be a pervasive and costly...

  11. Defect-assisted plasmonic crystal sensor

    PubMed Central

    Briscoe, Jayson L.; Cho, Sang-Yeon; Brener, Igal

    2014-01-01

    We demonstrate enhanced sensitivity of a nanostructured plasmonic sensor that utilizes resonance in intentional structural defects within a plasmonic crystal. The measured sensitivity of the fabricated nanosensor is ~500 nm/RIU showing improvement over traditional nanohole array sensors. Furthermore, the defects provide an additional design parameter to increase sensitivity by engineering plasmon lifetime. PMID:23939114

  12. Sizing Dye-Penetrant Indications Of Defects

    NASA Technical Reports Server (NTRS)

    Molina, Orlando G.

    1988-01-01

    Sizes of cracks and holes viewed through borescope measured. Reference chart makes it possible to estimate sizes of borescope-observed defects on inner walls of tubes or otherwise hidden. Used both for round defects like pits or pores and for elongated ones like cracks.

  13. Defect-Tolerant Monolayer Transition Metal Dichalcogenides.

    PubMed

    Pandey, Mohnish; Rasmussen, Filip A; Kuhar, Korina; Olsen, Thomas; Jacobsen, Karsten W; Thygesen, Kristian S

    2016-04-13

    Localized electronic states formed inside the band gap of a semiconductor due to crystal defects can be detrimental to the material's optoelectronic properties. Semiconductors with a lower tendency to form defect induced deep gap states are termed defect-tolerant. Here we provide a systematic first-principles investigation of defect tolerance in 29 monolayer transition metal dichalcogenides (TMDs) of interest for nanoscale optoelectronics. We find that the TMDs based on group VI and X metals form deep gap states upon creation of a chalcogen (S, Se, Te) vacancy, while the TMDs based on group IV metals form only shallow defect levels and are thus predicted to be defect-tolerant. Interestingly, all the defect sensitive TMDs have valence and conduction bands with a very similar orbital composition. This indicates a bonding/antibonding nature of the gap, which in turn suggests that dangling bonds will fall inside the gap. These ideas are made quantitative by introducing a descriptor that measures the degree of similarity of the conduction and valence band manifolds. Finally, the study is generalized to nonpolar nanoribbons of the TMDs where we find that only the defect sensitive materials form edge states within the band gap. PMID:27027786

  14. 49 CFR 215.123 - Defective couplers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Defective couplers. 215.123 Section 215.123 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION....123 Defective couplers. A railroad may not place or continue in service a car, if— (a) The car...

  15. 49 CFR 215.123 - Defective couplers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Defective couplers. 215.123 Section 215.123 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION....123 Defective couplers. A railroad may not place or continue in service a car, if— (a) The car...

  16. 49 CFR 215.123 - Defective couplers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Defective couplers. 215.123 Section 215.123 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION....123 Defective couplers. A railroad may not place or continue in service a car, if— (a) The car...

  17. 49 CFR 215.123 - Defective couplers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Defective couplers. 215.123 Section 215.123 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION....123 Defective couplers. A railroad may not place or continue in service a car, if— (a) The car...

  18. 27 CFR 11.32 - Defective products.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Defective products. 11.32 Section 11.32 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT... Beverages Exchanges and Returns for Ordinary and Usual Commercial Reasons § 11.32 Defective...

  19. Investigation of bone formation using calcium phosphate glass cement in beagle dogs

    PubMed Central

    Lee, Seung-Bum; Jung, Ui-Won; Choi, Youna; Jamiyandorj, Otgonbold; Kim, Chang-Sung; Lee, Yong-Keun; Chai, Jung-Kiu

    2010-01-01

    Purpose Among available biomaterials, bioceramics have drawn special interest due to their bioactivity and the possibility of tailoring their composition. The degradation rate and formulation of bioceramics can be altered to mimic the compositions of the mineral phase of bone. The aim of this study was to investigate the bone formation effect of amorphous calcium phosphate glass cement (CPGC) synthesized by a melting and quenching process. Methods In five male beagle dogs, 4 × 4 mm 1-wall intrabony defects were created bilaterally at the mesial or distal aspect of the mandibular second and fourth premolars. Each of the four defects was divided according to graft materials: CPGC with collagen membrane (CM), biphasic calcium phosphate (BCP) with CM, CM alone, or a surgical flap operation only. The dogs were sacrificed 8 weeks post-surgery, and block sections of the defects were collected for histologic and histometric analysis. Results There were significant differences in bone formation and cementum regeneration between the experimental and control groups. In particular, the CPGC and BCP groups showed greater bone formation than the CM and control groups. Conclusions In conclusion, CPGC was replaced rapidly with an abundant volume of new bone; CPGC also contributed slightly to regeneration of the periodontal apparatus. PMID:20607057

  20. Eggshell defects detection based on color processing

    NASA Astrophysics Data System (ADS)

    Garcia-Alegre, Maria C.; Ribeiro, Angela; Guinea, Domingo; Cristobal, Gabriel

    2000-03-01

    The automatic classification of defective eggs constitutes a fundamental issue at the poultry industry for both economical and sanitary reasons. The early separation of eggs with spots and cracks is a relevant task as the stains can leak while progressing on the conveyor-belts, degrading all the mechanical parts. Present work is focused on the implementation of an artificial vision system for detecting in real time defective eggs at the poultry farm. First step of the algorithmic process is devoted to the detection of the egg shape to fix the region of interest. A color processing is then performed only on the eggshell to obtain an image segmentation that allows the discrimination of defective eggs from clean ones in critic time. The results are presented to demonstrate the validity of the proposed visual process on a wide sample of both defective and non-defective eggs.

  1. Orbifolds, defects and sphere partition function

    NASA Astrophysics Data System (ADS)

    Hosomichi, Kazuo

    2016-02-01

    Gauge theories in the presence of codimension two vortex defects are known to be related to the theories on orbifolds. By using this relation we study the localized path integrals of 2D {N}=(2,2) SUSY gauge theories with point-like vortex defects. We present a formula for the correlation functions of vortex defects inserted at the north and the south poles of squashed spheres. For Abelian gauge theories the correlators are locally constant as functions of the parameters of the defect, but exhibit discontinuity at some threshold values determined from the R-charges of the matter multiplets. For non-Abelian gauge groups the correlators depend non-trivially on the types of gauge symmetry breaking due to the defects.

  2. Topological defect dynamics in operando battery nanoparticles

    NASA Astrophysics Data System (ADS)

    Ulvestad, Andrew; Meng, Shirley; Shpyrko, Oleg

    2015-03-01

    Topological defects are ubiquitous in physics and manifest themselves as magnetic monopoles in quantum field theories and crystallographic imperfections in condensed matter systems. In the latter, the defect properties determine many of the material's properties and as such represent substantial novel opportunities for design and optimization of desired functionalities through deliberate defect engineering and manipulation. However, this approach of ``defect choreography'' currently suffers from the lack of suitable nanoscale probes to track buried single defects in-situ and in-operando. Here we report 3D imaging of single edge dislocations and their motion in an individual nanoparticle under operando conditions in a Lithium ion battery. We further observe the dislocation act as a nucleation point during the structural phase transformation. We find that the region near the dislocation enters a negative Poisson's ratio, or auxetic, regime at high voltage. Dislocation imaging is thus a powerful nanotechnology and it opens a new, powerful avenue for facilitating improvement of nanostructured devices.

  3. Urgent global opportunities to prevent birth defects.

    PubMed

    Kancherla, Vijaya; Oakley, Godfrey P; Brent, Robert L

    2014-06-01

    Birth defects are an urgent global health priority. They affect millions of births worldwide. But their prevalence and impact are largely under-ascertained, particularly in middle- and low-income countries. Fortunately, a large proportion of birth defects can be prevented. This review examines the global prevalence and primary prevention methods for major preventable birth defects: congenital rubella syndrome, folic acid-preventable spina bifida and anencephaly, fetal alcohol syndrome, Down syndrome, rhesus hemolytic disease of the fetus and the newborn; and those associated with maternal diabetes, and maternal exposure to valproic acid or iodine deficiency during pregnancy. Challenges to prevention efforts are reviewed. The aim of this review is to bring to the forefront the urgency of birth defects prevention, surveillance, and prenatal screening and counseling; and to help public health practitioners develop population-based birth defects surveillance and prevention programs, and policy-makers to develop and implement science-based public health policies. PMID:24333206

  4. Native point defects in GaSb

    SciTech Connect

    Kujala, J.; Segercrantz, N.; Tuomisto, F.; Slotte, J.

    2014-10-14

    We have applied positron annihilation spectroscopy to study native point defects in Te-doped n-type and nominally undoped p-type GaSb single crystals. The results show that the dominant vacancy defect trapping positrons in bulk GaSb is the gallium monovacancy. The temperature dependence of the average positron lifetime in both p- and n-type GaSb indicates that negative ion type defects with no associated open volume compete with the Ga vacancies. Based on comparison with theoretical predictions, these negative ions are identified as Ga antisites. The concentrations of these negatively charged defects exceed the Ga vacancy concentrations nearly by an order of magnitude. We conclude that the Ga antisite is the native defect responsible for p-type conductivity in GaSb single crystals.

  5. Geodesic defect anchoring on nematic shells.

    PubMed

    Mirantsev, Leonid V; Sonnet, André M; Virga, Epifanio G

    2012-08-01

    Nematic shells are colloidal particles coated with nematic liquid crystal molecules, which may freely glide and rotate on the colloid's surface while keeping their long axis on the local tangent plane. Molecular dynamics simulations on a nanoscopic spherical shell indicate that under appropriate adhesion conditions for the molecules on the equator, the equilibrium nematic texture exhibits at each pole a pair of +1/2 defects so close to one another to be treated as one +1 defect. Spirals connect the polar defects, though the continuum limit of the interaction potential would not feature any elastic anisotropy. A molecular averaging justifies an anchoring defect energy that feels the geodesics emanating from the defect. All our observations are explained by such a geodesic anchoring, which vanishes on flat manifolds. PMID:23005713

  6. Wafer plane inspection for advanced reticle defects

    NASA Astrophysics Data System (ADS)

    Nagpal, Rajesh; Ghadiali, Firoz; Kim, Jun; Huang, Tracy; Pang, Song

    2008-05-01

    Readiness of new mask defect inspection technology is one of the key enablers for insertion & transition of the next generation technology from development into production. High volume production in mask shops and wafer fabs demands a reticle inspection system with superior sensitivity complemented by a low false defect rate to ensure fast turnaround of reticle repair and defect disposition (W. Chou et al 2007). Wafer Plane Inspection (WPI) is a novel approach to mask defect inspection, complementing the high resolution inspection capabilities of the TeraScanHR defect inspection system. WPI is accomplished by using the high resolution mask images to construct a physical mask model (D. Pettibone et al 1999). This mask model is then used to create the mask image in the wafer aerial plane. A threshold model is applied to enhance the inspectability of printing defects. WPI can eliminate the mask restrictions imposed on OPC solutions by inspection tool limitations in the past. Historically, minimum image restrictions were required to avoid nuisance inspection stops and/or subsequent loss of sensitivity to defects. WPI has the potential to eliminate these limitations by moving the mask defect inspections to the wafer plane. This paper outlines Wafer Plane Inspection technology, and explores the application of this technology to advanced reticle inspection. A total of twelve representative critical layers were inspected using WPI die-to-die mode. The results from scanning these advanced reticles have shown that applying WPI with a pixel size of 90nm (WPI P90) captures all the defects of interest (DOI) with low false defect detection rates. In validating CD predictions, the delta CDs from WPI are compared against Aerial Imaging Measurement System (AIMS), where a good correlation is established between WPI and AIMSTM.

  7. Constitutional and thermal defects in nickel aluminides

    SciTech Connect

    Korzhavyi, P.A.; Abrikosov, I.A.; Johansson, B.

    1999-07-01

    The formation energies of intrinsic point defects and the interaction energies of possible defect pairs in NiAl are calculated from first principles within an order-N, locally self-consistent Green's function method in conjunction with the multipole electrostatic corrections to the atomic sphere approximation. The theory correctly reproduces the ground-state properties of the off-stoichiometric NiAl alloys. The constitutional defects (antisite Ni atoms in Ni-rich and Ni vacancies in Al-rich NiAl) are shown to form ordered structures in the ground state, in which the defects of the same kind tend to avoid each other at the shortest separation distance on their sublattice. A mean-field theory is applied to calculate the equilibrium concentrations of thermal defects. The statistics of thermal defects is interpreted in terms of dominant composition-conserving complex defects which are shown to be triple defects in Ni-rich and nearly stoichiometric NiAl. In the Al-rich region a novel thermal excitation dominates where two constitutional Ni vacancies are replaced by one antisite Al atom. The number of vacancies, as well as the total number of point defects decrease with temperature in Al-rich NiAl. The boundary between the two regions is treated analytically. The vacancy concentration exhibits a minimum in its temperature dependence at the boundary. Similar analysis is applied to study constitutional and thermal defects in Ni{sub 3}Al as a function of concentration is in excellent agreement with recent experimental data.

  8. The role of point defects and defect complexes in silicon device processing. Summary report and papers

    SciTech Connect

    Sopori, B.; Tan, T.Y.

    1994-08-01

    This report is the summary of the third workshop on the role of point defects and defect complexes in silicon device processing. The workshop was organized: (1) to discuss recent progress in the material quality produced by photovoltaic Si manufacturers, (2) to foster the understanding of point defect issues in Si device processing, (3) to review the effects of inhomogeneities on large- area solar cell performance, (4) to discuss how to improve Si solar cell processing, and (5) to develop a new understanding of gettering, defect passivation, and defect annihilation. Separate abstract were prepared for the individual papers, for the database.

  9. Interleukin-6 Stimulates Defective Angiogenesis.

    PubMed

    Gopinathan, Ganga; Milagre, Carla; Pearce, Oliver M T; Reynolds, Louise E; Hodivala-Dilke, Kairbaan; Leinster, David A; Zhong, Haihong; Hollingsworth, Robert E; Thompson, Richard; Whiteford, James R; Balkwill, Frances

    2015-08-01

    The cytokine IL6 has a number of tumor-promoting activities in human and experimental cancers, but its potential as an angiogenic agent has not been fully investigated. Here, we show that IL6 can directly induce vessel sprouting in the ex vivo aortic ring model, as well as endothelial cell proliferation and migration, with similar potency to VEGF. However, IL6-stimulated aortic ring vessel sprouts had defective pericyte coverage compared with VEGF-stimulated vessels. The mechanism of IL6 action on pericytes involved stimulation of the Notch ligand Jagged1 as well as angiopoietin2 (Ang2). When peritoneal xenografts of ovarian cancer were treated with an anti-IL6 antibody, pericyte coverage of vessels was restored. In addition, in human ovarian cancer biopsies, there was an association between levels of IL6 mRNA, Jagged1, and Ang2. Our findings have implications for the use of cancer therapies that target VEGF or IL6 and for understanding abnormal angiogenesis in cancers, chronic inflammatory disease, and stroke. PMID:26081809

  10. Intraventricular haemorrhage and haemostasis defects.

    PubMed Central

    Beverley, D W; Chance, G W; Inwood, M J; Schaus, M; O'Keefe, B

    1984-01-01

    Twenty five of 106 preterm infants of 34 weeks' gestation or less developed intraventricular haemorrhage within the first 48 hours of life. A comparison of infants with and without intraventricular haemorrhage showed no significant differences in their haemostatic parameters at birth. At age 48 hours the group with intraventricular haemorrhage showed a prolonged activated partial thromboplastin time and reduced factor II, VII, and X activity. There was a significant correlation between the severity of intraventricular haemorrhage and the degree of haemostasis abnormality both in cord blood and in blood obtained at age 48 hours. Those infants sustaining grade IV intraventricular haemorrhage had a significantly prolonged activated partial thromboplastin time, reduced factor II, VII, and X activity; and a decreased fibrinogen concentration at birth. At age 48 hours these defects were accompanied by reduced platelet counts and an increased megathrombocyte index. Although intraventricular haemorrhage is multifactorial, we postulate that correction of haemostasis abnormalities at birth may prevent progression to more severe grades of haemorrhage. PMID:6732274

  11. Symmetry fractionalization and twist defects

    NASA Astrophysics Data System (ADS)

    Tarantino, Nicolas; Lindner, Netanel H.; Fidkowski, Lukasz

    2016-03-01

    Topological order in two-dimensions can be described in terms of deconfined quasiparticle excitations—anyons—and their braiding statistics. However, it has recently been realized that this data does not completely describe the situation in the presence of an unbroken global symmetry. In this case, there can be multiple distinct quantum phases with the same anyons and statistics, but with different patterns of symmetry fractionalization—termed symmetry enriched topological order. When the global symmetry group G, which we take to be discrete, does not change topological superselection sectors—i.e. does not change one type of anyon into a different type of anyon—one can imagine a local version of the action of G around each anyon. This leads to projective representations and a group cohomology description of symmetry fractionalization, with the second cohomology group {H}2(G,{{ A }}{{abelian}}) being the relevant group. In this paper, we treat the general case of a symmetry group G possibly permuting anyon types. We show that despite the lack of a local action of G, one can still make sense of a so-called twisted group cohomology description of symmetry fractionalization, and show how this data is encoded in the associativity of fusion rules of the extrinsic ‘twist’ defects of the symmetry. Furthermore, building on work of Hermele (2014 Phys. Rev. B 90 184418), we construct a wide class of exactly-solvable models which exhibit this twisted symmetry fractionalization, and connect them to our formal framework.

  12. Oral contraceptives and birth defects.

    PubMed

    Smithells, R W

    1981-06-01

    Although OCs (oral contraceptives) are not designed to be taken during pregnancy, in Europe and the U.S. they are taken by 2-5% of women in early pregnancy and by 1/4-1/3 of women 3-4 months prior to conception. The effects of OCs on folic acid and other vitamin metabolism are well known and provide a theoretical basis for possible teratogenicity, even when stopped prior to conception. Both hormone support therapy for threatened abortions and hormonal pregnancy tests have been abandoned in recent years, the first because it proved inefficacious, the second because there are better alternatives available. In neither of these cases were sex hormones shown to be teratogenic. Most cohort (prospective) and many case-control (retrospective) studies have shown no association between OC use and birth defects. Case-control methodology can be criticized because of recall bias and because of the difficulty of choosing entirely matched controls. Several studies have shown OC users to have characteristics slightly different from the general population, e.g., they are younger, more often unmarried, and are more likely to smoke during pregnancy. Any of these characteristics might influence the occurrence of teratogenicity. It is impossible to prove that OCs constitute a low-level teratogen. The author considers them nonteratogenic. PMID:7250546

  13. DIVAS: fully automated simulation based mask defect dispositioning and defect management system

    NASA Astrophysics Data System (ADS)

    Munir, Saghir; Bald, Daniel J.; Tolani, Vikram; Ghadiali, Firoz; Lieberman, Barry

    2004-12-01

    This article presents the evolution of the first fully automated simulation based mask defect dispositioning and defect management system used since late 2002 in a production environment at Intel Mask Operation (IMO). Given that inspection tools flag defects which may or may not have any lithographic significance, it makes sense to repair only those defects that resolve on the wafer. The system described here is a fully automated defect dispositioning system, where the lithographic impact of a defect is determined through computer simulation of the mask level image. From the simulated aerial images, combined with image processing techniques, the system can automatically determine the actual critical dimension (CD) impact (in nanometers). Then, using the product specification as a criteria, can pass or fail the defect. Furthermore, this system allows engineers and technicians in the factory to track defects as they are repaired, compare defects at various inspection steps and annotate repair history. Trends such as yield and defect commonality can also be determined. The article concludes with performance results, indicating the speed and accuracy of the system, as well as the savings in the number of defects needing repair.

  14. An overview of hgcdte mbe defects and analysis of defect size

    NASA Astrophysics Data System (ADS)

    Olsson, Kurt Robert

    HgCdTe is the most widely used material for high performance infrared detection applications. Growth of HgCdTe epitaxial layers by molecular beam epitaxy (MBE) has ushered in advanced devices that take advantage of the unique properties of the material. Formation of defects during the growth process is one of the largest drawbacks to this technology, and must be minimized to increase device operability. In this paper, the defects encountered in HgCdTe are categorized, along with formation mechanisms and possible means of reduction. A new method of defect identification is proposed, which takes advantage of full wafer defect mapping capabilities. A correlation between the thickness of the grown film and the size of defects initiated at the substrate surface is found. This allows further defect information to be extracted from the size and density of the defects.

  15. DIVAS: an integrated networked system for mask defect dispositioning and defect management

    NASA Astrophysics Data System (ADS)

    Munir, Saghir; Bald, Dan; Tolani, Vikram; Ghadiali, Firoz

    2003-06-01

    Mask quality is a prime concern to the Intel Mask Operation (IMO) and the Intel wafer fabrication customers. Extreme concern is taken to inspect and repair all defects before shipment. Given that the classification and repair of defects detected by inspection systems is labor intensive, the procedure is prone to human error. Futhermore, since operators manually disposition hundreds of defects each day, it is virtually impossible to eliminate all misclassifications. Due to diffraction effects, not all defects resolve on a wafer. Hence, a defect that an operator may classify as 'real' may indeed be 'lithographically insignifincant'. Conversely an operator may miss a defect that prints, causing a serious reduction in product yield. The DIVAS (Defect, Inspection, Viewing, Archiving and Simulation) system has been described previously and was developed to address these manual classification issues. This paper outlines the fully automated system deployed in a production environment.

  16. Studying post-etching silicon crystal defects on 300mm wafer by automatic defect review AFM

    NASA Astrophysics Data System (ADS)

    Zandiatashbar, Ardavan; Taylor, Patrick A.; Kim, Byong; Yoo, Young-kook; Lee, Keibock; Jo, Ahjin; Lee, Ju Suk; Cho, Sang-Joon; Park, Sang-il

    2016-03-01

    Single crystal silicon wafers are the fundamental elements of semiconductor manufacturing industry. The wafers produced by Czochralski (CZ) process are very high quality single crystalline materials with known defects that are formed during the crystal growth or modified by further processing. While defects can be unfavorable for yield for some manufactured electrical devices, a group of defects like oxide precipitates can have both positive and negative impacts on the final device. The spatial distribution of these defects may be found by scattering techniques. However, due to limitations of scattering (i.e. light wavelength), many crystal defects are either poorly classified or not detected. Therefore a high throughput and accurate characterization of their shape and dimension is essential for reviewing the defects and proper classification. While scanning electron microscopy (SEM) can provide high resolution twodimensional images, atomic force microscopy (AFM) is essential for obtaining three-dimensional information of the defects of interest (DOI) as it is known to provide the highest vertical resolution among all techniques [1]. However AFM's low throughput, limited tip life, and laborious efforts for locating the DOI have been the limitations of this technique for defect review for 300 mm wafers. To address these limitations of AFM, automatic defect review AFM has been introduced recently [2], and is utilized in this work for studying DOI on 300 mm silicon wafer. In this work, we carefully etched a 300 mm silicon wafer with a gaseous acid in a reducing atmosphere at a temperature and for a sufficient duration to decorate and grow the crystal defects to a size capable of being detected as light scattering defects [3]. The etched defects form a shallow structure and their distribution and relative size are inspected by laser light scattering (LLS). However, several groups of defects couldn't be properly sized by the LLS due to the very shallow depth and low

  17. Geometric defects in quantum Hall states

    NASA Astrophysics Data System (ADS)

    Gromov, Andrey

    2016-08-01

    We describe a geometric (or gravitational) analog of the Laughlin quasiholes in fractional quantum Hall states. Analogously to the quasiholes, these defects can be constructed by an insertion of an appropriate vertex operator into the conformal block representation of a trial wave function; however, unlike the quasiholes these defects are extrinsic and do not correspond to true excitations of the quantum fluid. We construct a wave function in the presence of such defects and explain how to assign an electric charge and a spin to each defect and calculate the adiabatic, non-Abelian statistics of the defects. The defects turn out to be equivalent to the genons in that their adiabatic exchange statistics can be described in terms of representations of the mapping class group of an appropriate higher genus Riemann surface. We present a general construction that, in principle, makes it possible to calculate the statistics of Zn genons for any "parent" topological phase. We illustrate the construction on the example of the Laughlin state and perform an explicit calculation of the braiding matrices. In addition to non-Abelian statistics, geometric defects possess a universal Abelian overall phase, determined by the gravitational anomaly.

  18. Platelet rich fibrin in jaw defects

    NASA Astrophysics Data System (ADS)

    Nica, Diana; Ianes, Emilia; Pricop, Marius

    2016-03-01

    Platelet rich fibrin (PRF) is a tissue product of autologous origin abundant in growth factors, widely used in regenerative procedures. Aim of the study: Evaluation of the regenerative effect of PRF added in the bony defects (after tooth removal or after cystectomy) Material and methods: The comparative nonrandomized study included 22 patients divided into 2 groups. The first group (the test group) included 10 patients where the bony defects were treated without any harvesting material. The second group included 12 patients where the bony defects were filled with PRF. The bony defect design was not critical, with one to two walls missing. After the surgeries, a close clinically monitoring was carried out. The selected cases were investigated using both cone beam computer tomography (CBCT) and radiographic techniques after 10 weeks postoperatively. Results: Faster bone regeneration was observed in the bony defects filled with PRF comparing with the not grafted bony defects. Conclusions: PRF added in the bony defects accelerates the bone regeneration. This simplifies the surgical procedures and decreases the economic costs.

  19. Exploring atomic defects in molybdenum disulphide monolayers

    PubMed Central

    Hong, Jinhua; Hu, Zhixin; Probert, Matt; Li, Kun; Lv, Danhui; Yang, Xinan; Gu, Lin; Mao, Nannan; Feng, Qingliang; Xie, Liming; Zhang, Jin; Wu, Dianzhong; Zhang, Zhiyong; Jin, Chuanhong; Ji, Wei; Zhang, Xixiang; Yuan, Jun; Zhang, Ze

    2015-01-01

    Defects usually play an important role in tailoring various properties of two-dimensional materials. Defects in two-dimensional monolayer molybdenum disulphide may be responsible for large variation of electric and optical properties. Here we present a comprehensive joint experiment–theory investigation of point defects in monolayer molybdenum disulphide prepared by mechanical exfoliation, physical and chemical vapour deposition. Defect species are systematically identified and their concentrations determined by aberration-corrected scanning transmission electron microscopy, and also studied by ab-initio calculation. Defect density up to 3.5 × 1013 cm−2 is found and the dominant category of defects changes from sulphur vacancy in mechanical exfoliation and chemical vapour deposition samples to molybdenum antisite in physical vapour deposition samples. Influence of defects on electronic structure and charge-carrier mobility are predicted by calculation and observed by electric transport measurement. In light of these results, the growth of ultra-high-quality monolayer molybdenum disulphide appears a primary task for the community pursuing high-performance electronic devices. PMID:25695374

  20. Resist dispense system for further defect reduction

    NASA Astrophysics Data System (ADS)

    Yamamoto, Yusuke; Nishi, Kouzo; Takayanagi, Koji; Okubo, Takahiro; Furusho, Toshinobu; Yoshihara, Kosuke; Shibata, Tsuyoshi

    2011-04-01

    As pattern size becomes smaller, requirement for defect reduction is getting higher and higher. It is known that defects occur in various steps of lithography process. In this study, we focus on defects related to the resist dispense system. Of those defects, the most typical is bridge type defect which caused by foreign substances contained in resist film. The source of those is considered to be insoluble substances, such as resist gels, in resist liquid. So far, the conventional countermeasure has been the development of resist line filters (optimization of materials, shrinking of pore size, and so on). But, according to the recent reports and our experimental result, we can say that not only filter type but also filtration condition has certain influence on bridge type defect generation. In this study, we examine the influences of resist dispense system and its parameters on bridge type defect generation. This paper provides some experimental data and introduces our approaches to the optimization of resist dispense system and its effects.

  1. Robust defect segmentation in woven fabrics

    SciTech Connect

    Sari-Sarraf, H.; Goddard, J.S. Jr.

    1997-12-01

    This paper describes a robust segmentation algorithm for the detection and localization of woven fabric defects. The essence of the presented segmentation algorithm is the localization of those events (i.e., defects) in the input images that disrupt the global homogeneity of the background texture. To this end, preprocessing modules, based on the wavelet transform and edge fusion, are employed with the objective of attenuating the background texture and accentuating the defects. Then, texture features are utilized to measure the global homogeneity of the output images. If these images are deemed to be globally nonhomogeneous (i.e., defects are present), a local roughness measure is used to localize the defects. The utility of this algorithm can be extended beyond the specific application in this work, that is, defect segmentation in woven fabrics. Indeed, in a general sense, this algorithm can be used to detect and to localize anomalies that reside in images characterized by ordered texture. The efficacy of this algorithm has been tested thoroughly under realistic conditions and as a part of an on-line fabric inspection system. Using over 3700 images of fabrics, containing 26 different types of defects, the overall detection rate of this approach was 89% with a localization accuracy of less than 0.2 inches and a false alarm rate of 2.5%.

  2. Defects and metrology of ultrathin resist films

    NASA Astrophysics Data System (ADS)

    Okoroanyanwu, Uzodinma; Cobb, Jonathan L.; Dentinger, Paul M.; Henderson, Craig C.; Rao, Veena; Monahan, Kevin M.; Luo, David; Pike, Christopher

    2000-06-01

    Defectivity in spin-coated, but unpatterned ultrathin resist (UTR) films (defectivity will present an issue in EUV (13.4-nm) and 157-nm lithographic technologies. These are the lithographic regimes where absorption issues mandate the use of ultrathin resists. Four resist samples formulated from the same Shipley UV6 polymer batch and having the same polymer molecular weight properties but different viscosities, were spin-coated at spin speeds ranging from 1000 to 5000 RPM on a production-grade track in a Class 1 pilot line facility. Defect inspection was carried out with KLA SP1/TBI tool, while defect review was carried out with JEOL 7515 SEM tool and KLA Ultrapointe Confocal Review Station (CRS) Microscope. The results obtained are related to the physical properties of the resist polymers, as well as to spin coating parameters. Also, the results of the defect inspection, review, characterization, and pareto are compared to those obtained on baseline thick resists (>= 3500 Angstrom) processed under similar condition as the ultra-thin resists. The results show that for a well-optimized coating process and within the thickness range explored (800 - 4200 Angstrom), there is no discernible dependence of defectivity on film thickness of the particular resists studied and on spin speed. Also assessed is the capability of the current metrology toolset for inspecting, reviewing, and classifying the various types of defects in UTR films.

  3. [Congenital thoracic defects demonstrated by radiophotography].

    PubMed

    Jonescu, N; Ionescu, G C

    1991-01-01

    Costal congenital defects are malformations or anomalies of dimension, location or structure of the ribs, generated by disturbances of prenatal development. These anomalies appear in mesoderm which also gives rise to skeleton, muscles, serums, conjunctive tissues, circulatory system and urogenital apparatus. Of the 59,225 persons examined, 502 had costal congenital defects. The presence of azygos lobe (Wrisberg's lobe) in 158 cases (0.26%), of right aortic (arcs high dextroposition of cross) in 2 cases and (3%000) dextroposition of heart in 6 cases (10%000), out of which a situs inversus (complete cardiovascular transposition) were noticed as congenital defects with common origin in embryonic mesoderm. Medical radiophotography can be used as a method in detecting congenital costal defects. Other defects in other organs can be also detected. The congenital costal defects found in an rf examined population, representing a part of the total of congenital malformations, may be one of their indirect epidemiologic indices. Their existence may lead to the explanation of the symptomatology of the nervous compressive type on brachiocephalic vascular, etc. plexus. As some of the defects are an excess of osseous and cartilaginous matter, they may be used, when indicated, as autografts. PMID:1823198

  4. Exploring atomic defects in molybdenum disulphide monolayers.

    PubMed

    Hong, Jinhua; Hu, Zhixin; Probert, Matt; Li, Kun; Lv, Danhui; Yang, Xinan; Gu, Lin; Mao, Nannan; Feng, Qingliang; Xie, Liming; Zhang, Jin; Wu, Dianzhong; Zhang, Zhiyong; Jin, Chuanhong; Ji, Wei; Zhang, Xixiang; Yuan, Jun; Zhang, Ze

    2015-01-01

    Defects usually play an important role in tailoring various properties of two-dimensional materials. Defects in two-dimensional monolayer molybdenum disulphide may be responsible for large variation of electric and optical properties. Here we present a comprehensive joint experiment-theory investigation of point defects in monolayer molybdenum disulphide prepared by mechanical exfoliation, physical and chemical vapour deposition. Defect species are systematically identified and their concentrations determined by aberration-corrected scanning transmission electron microscopy, and also studied by ab-initio calculation. Defect density up to 3.5 × 10(13) cm(-2) is found and the dominant category of defects changes from sulphur vacancy in mechanical exfoliation and chemical vapour deposition samples to molybdenum antisite in physical vapour deposition samples. Influence of defects on electronic structure and charge-carrier mobility are predicted by calculation and observed by electric transport measurement. In light of these results, the growth of ultra-high-quality monolayer molybdenum disulphide appears a primary task for the community pursuing high-performance electronic devices. PMID:25695374

  5. Point defects in yttria-stabilized zirconia

    NASA Astrophysics Data System (ADS)

    Hellberg, C. Stephen; Bernstein, Noam; Erwin, Steven C.

    The densification that occurs during sintering of certain ceramics has been observed to occur more rapidly and at lower temperatures when a weak external electric field is applied.1 We compute the formation energies of point defects in yttria-stabilized zirconia using first principles density functional theory. We examine interstitials, vacancies, and vacancy complexes including Schottky defects in a Y2Zr14O31 computational cell, which corresponds to approximately 7 mol% yttria stabilized zirconia. We relate our results to recent experimental work on electric-field-assisted sintering in yttria-stabilized zirconia, showing how how the expansion of lattice constants observed in diffraction measurements results from increasing defect densities.

  6. CDC Reports Six Cases of Birth Defects Caused by Zika

    MedlinePlus

    ... Reports Six Cases of Birth Defects Caused by Zika Three babies born with defects, while three pregnancies ... 2016 (HealthDay News) -- In the first reporting of Zika-related birth defects in the United States, federal ...

  7. Genetics Home Reference: congenital bile acid synthesis defect type 1

    MedlinePlus

    ... bile acid synthesis defect type 1 congenital bile acid synthesis defect type 1 Enable Javascript to view ... PDF Open All Close All Description Congenital bile acid synthesis defect type 1 is a disorder characterized ...

  8. Genetics Home Reference: congenital bile acid synthesis defect type 2

    MedlinePlus

    ... bile acid synthesis defect type 2 congenital bile acid synthesis defect type 2 Enable Javascript to view ... PDF Open All Close All Description Congenital bile acid synthesis defect type 2 is a disorder characterized ...

  9. Defect chemistry and defect engineering of TiO2-based semiconductors for solar energy conversion.

    PubMed

    Nowotny, Janusz; Alim, Mohammad Abdul; Bak, Tadeusz; Idris, Mohammad Asri; Ionescu, Mihail; Prince, Kathryn; Sahdan, Mohd Zainizan; Sopian, Kamaruzzaman; Mat Teridi, Mohd Asri; Sigmund, Wolfgang

    2015-12-01

    This tutorial review considers defect chemistry of TiO2 and its solid solutions as well as defect-related properties associated with solar-to-chemical energy conversion, such as Fermi level, bandgap, charge transport and surface active sites. Defect disorder is discussed in terms of defect reactions and the related charge compensation. Defect equilibria are used in derivation of defect diagrams showing the effect of oxygen activity and temperature on the concentration of both ionic and electronic defects. These defect diagrams may be used for imposition of desired semiconducting properties that are needed to maximize the performance of TiO2-based photoelectrodes for the generation of solar hydrogen fuel using photo electrochemical cells (PECs) and photocatalysts for water purification. The performance of the TiO2-based semiconductors is considered in terms of the key performance-related properties (KPPs) that are defect related. It is shown that defect engineering may be applied for optimization of the KPPs in order to achieve optimum performance. PMID:26446476

  10. Defect classes - an overdue paradigm for CMOS IC testing

    SciTech Connect

    Hawkins, C.F.; Soden, J.M.; Righter, A.W.; Ferguson, F.J.

    1994-09-01

    The IC test industry has struggled for more than 30 years to establish a test approach that would guarantee a low defect level to the customer. We propose a comprehensive strategy for testing CMOS ICs that uses defect classes based on measured defect electrical properties. Defect classes differ from traditional fault models. Our defect class approach requires that the test strategy match the defect electrical properties, while fault models require that IC defects match the fault definition. We use data from Sandia Labs failure analysis and test facilities and from public literature. We describe test pattern requirements for each defect class and propose a test paradigm.

  11. The Knobbed Acrosome Defect in Beef Bulls

    PubMed Central

    Barth, Albert D.

    1986-01-01

    The knobbed acrosome defect was found at levels of 25 to 100 percent of spermatozoa from 16 of 2054 beef bulls. The incidence of this defect appeared to be particularly high in the Charolais breed. Pedigree analysis of some of the affected Charolais bulls indicated there may be a genetic predisposition for this sperm defect. In eosin-nigrosin stained semen smears the most common form of the abnormality was a flattened or indented apex of the sperm head. A refractile bead at the apex of the sperm head was seen less commonly. Electron microscopy of the spermatozoa from one bull showed that the abnormality was similar to the knobbed sperm defect previously described in Friesian bulls. A breeding trial confirmed that bulls producing spermatozoa with a high incidence of knobbed acrosomes are infertile. ImagesFigure 2 and 3.Figure 4.Figure 5.Figure 6 and 7.Figure 8.Figure 9.Figure 10. PMID:17422706

  12. Topological defect dynamics in operando battery nanoparticles

    NASA Astrophysics Data System (ADS)

    Ulvestad, A.; Singer, A.; Clark, J. N.; Cho, H. M.; Kim, J. W.; Harder, R.; Maser, J.; Meng, Y. S.; Shpyrko, O. G.

    2015-06-01

    Topological defects can markedly alter nanomaterial properties. This presents opportunities for “defect engineering,” where desired functionalities are generated through defect manipulation. However, imaging defects in working devices with nanoscale resolution remains elusive. We report three-dimensional imaging of dislocation dynamics in individual battery cathode nanoparticles under operando conditions using Bragg coherent diffractive imaging. Dislocations are static at room temperature and mobile during charge transport. During the structural phase transformation, the lithium-rich phase nucleates near the dislocation and spreads inhomogeneously. The dislocation field is a local probe of elastic properties, and we find that a region of the material exhibits a negative Poisson’s ratio at high voltage. Operando dislocation imaging thus opens a powerful avenue for facilitating improvement and rational design of nanostructured materials.

  13. Living with a Congenital Heart Defect

    MedlinePlus

    ... well the heart’s chambers and valves are working. Health Insurance and Employment Adults who have congenital heart defects ... carefully consider how changing jobs will affect their health insurance coverage. Some health plans have waiting periods or ...

  14. When Your Baby Has a Birth Defect

    MedlinePlus

    ... Ones & When? Smart School Lunches Emmy-Nominated Video "Cerebral Palsy: Shannon's Story" 5 Things to Know About Zika & ... as heart defects, cleft lip and palate, or cerebral palsy, you may find yourself having to serve as ...

  15. Holographic entanglement entropy of surface defects

    NASA Astrophysics Data System (ADS)

    Gentle, Simon A.; Gutperle, Michael; Marasinou, Chrysostomos

    2016-04-01

    We calculate the holographic entanglement entropy in type IIB supergravity solutions that are dual to half-BPS disorder-type surface defects in N=4 supersymmetric Yang-Mills theory. The entanglement entropy is calculated for a ball-shaped region bisected by a surface defect. Using the bubbling supergravity solutions we also compute the expectation value of the defect operator. Combining our result with the previously-calculated one-point function of the stress tensor in the presence of the defect, we adapt the calculation of Lewkowycz and Maldacena [1] to obtain a second expression for the entanglement entropy. Our two expressions agree up to an additional term, whose possible origin and significance is discussed.

  16. 49 CFR 213.113 - Defective rails.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... center or nucleus inside the head from which it spreads outward as a smooth, bright, or dark round or... transverse fissure from other types of fractures or defects are the crystalline center or nucleus and...

  17. National Birth Defects Prevention Study (NBDPS)

    MedlinePlus

    ... were taking multivitamins before their pregnancy. [ Read Summary ] Air Pollution and Congenital Heart Defects Many pregnant women, especially ... research is needed to learn what levels of air pollution affect an unborn baby. [ Read Summary ] The Potential ...

  18. Genetic Counseling for Congenital Heart Defects

    MedlinePlus

    ... Pressure High Blood Pressure Tools & Resources Stroke More Genetic Counseling for Congenital Heart Defects Updated:Oct 26, ... person with congenital heart disease considers having children. Genetic counseling can help answer these questions and address ...

  19. Phase measurements of EUV mask defects

    DOE PAGESBeta

    Claus, Rene A.; Wang, Yow-Gwo; Wojdyla, Antoine; Benk, Markus P.; Goldberg, Kenneth A.; Neureuther, Andrew R.; Naulleau, Patrick P.; Waller, Laura

    2015-02-22

    Extreme Ultraviolet (EUV) Lithography mask defects were examined on the actinic mask imaging system, SHARP, at Lawrence Berkeley National Laboratory. Also, a quantitative phase retrieval algorithm based on the Weak Object Transfer Function was applied to the measured through-focus aerial images to examine the amplitude and phase of the defects. The accuracy of the algorithm was demonstrated by comparing the results of measurements using a phase contrast zone plate and a standard zone plate. Using partially coherent illumination to measure frequencies that would otherwise fall outside the numerical aperture (NA), it was shown that some defects are smaller than themore » conventional resolution of the microscope. We found that the programmed defects of various sizes were measured and shown to have both an amplitude and a phase component that the algorithm is able to recover.« less

  20. Folic Acid Helps Prevent Neural Tube Defects

    MedlinePlus

    ... Features Folic Acid Helps Prevent Neural Tube Defects Language: English Español (Spanish) Recommend on Facebook Tweet Share Compartir The feature you selected is no longer available. In 10 seconds you will be automatically redirected to the CDC. ...

  1. Color Vision Defects: What Teachers Should Know.

    ERIC Educational Resources Information Center

    Lewis, Barbara A.; And Others

    1990-01-01

    Discusses the nature of color vision defects as they relate to reading instruction. Suggests ways that teachers can adapt instruction to help provide maximal learning opportunities for the color deficient child. (RS)

  2. Highly Defective Graphene: The thinnest insulating membrane

    NASA Astrophysics Data System (ADS)

    Lherbier, Aurelien; Roche, Stephan; Restrepo, Oscar A.; Niquet, Yann-Michel; Delcorte, Arnaud; Charlier, Jean-Christophe

    2012-02-01

    The electronic structure and transport properties of two-dimensional highly defective sp2 graphene are investigated theoretically. Using classical molecular dynamics, large planes of highly defective graphene-based sheets are first generated. An accurate empirical tight-binding Hamiltonian is then elaborated, allowing the prediction of elastic mean free paths, conductivities, and charge mobilities using a real-space order-N Kubo-Greenwood method. In sharp contrast to pristine graphene, the highly defective sp2 carbon sheet displays high density of states close to the Dirac energy. However, the dynamics of the corresponding electronic wavepackets reveals extremely short mean free paths (below 1 nanometer) and quantum interferences, both yielding to particularly strong localization phenomena. Consequently, these highly defective graphene-based sheets, although exhibiting a metallic character through the density of states, are from an electronic transport perspective among the most insulating two-dimensional one-atom-thick membrane ever made.

  3. [Defect replacement with osteogenin containing gelatin].

    PubMed

    Thielemann, F W; Feller, A M; Schmidt, K

    1984-01-01

    In order to demonstrate an alternative way to correct diaphyseal defects allogenic cortical bone prepared as "osteogenin containing gelatine (OCG)" was used in sheep. Animals without any implants served as controls. Healing was assessed by radiological examination after 3, 6, 9 and 12 weeks and histological examination after 12 weeks. In the control group there was no bridging of the defect in all of the four animals. Out of the six animals of the OCG-group one animal suffered from a postoperative infection and one animal failed because of a breakdown of the osteosynthesis. The other four animals exhibited a complete reconstruction of the former defect roentgenologically after 9 weeks. Histologically a new formed spongious bone could be demonstrated in the former defective site. The OCG-implants were completely resorbed after 12 weeks. PMID:6395536

  4. Vacancies and antisite defects in ordered alloys

    SciTech Connect

    Johnson, R.A.; Brown, J.R. )

    1992-12-01

    Equations for the concentrations of vacancies and antisite defects in ordered alloys in thermodynamic equilibrium at and near stoichiometry have been derived as functions of defect energies and a Lagrangian parameter. While the resulting equations cannot be solved analytically and in general require iterative calculations, an approximation is given that permits simple numerical evaluation with just a minor loss of accuracy. Using defect energies obtained from an embedded-atom method calculation for Cu[sub 3]Au, it is found that the adjustment for off-stoichiometric compositions is accounted for primarily by the creation of antisite defects rather than vacancies, and the vacancy concentration on Au sites is orders of magnitude less than that on Cu sites. There is a significant increase in the Au vacancy concentration but a slight decrease in the net vacancy content with increasing Cu fraction.

  5. 47 CFR 25.112 - Defective applications.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... application requests authority to operate a space station in a frequency band that is not allocated... § 25.158. (b) Applications for space station authority found defective under paragraph (a)(3) of...

  6. 47 CFR 25.112 - Defective applications.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... application requests authority to operate a space station in a frequency band that is not allocated...) Applications for space station authority found defective under paragraph (a)(3) of this section will not...

  7. 47 CFR 25.112 - Defective applications.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... application requests authority to operate a space station in a frequency band that is not allocated...) Applications for space station authority found defective under paragraph (a)(3) of this section will not...

  8. 47 CFR 25.112 - Defective applications.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... application requests authority to operate a space station in a frequency band that is not allocated...) Applications for space station authority found defective under paragraph (a)(3) of this section will not...

  9. Phase measurements of EUV mask defects

    SciTech Connect

    Claus, Rene A.; Wang, Yow-Gwo; Wojdyla, Antoine; Benk, Markus P.; Goldberg, Kenneth A.; Neureuther, Andrew R.; Naulleau, Patrick P.; Waller, Laura

    2015-02-22

    Extreme Ultraviolet (EUV) Lithography mask defects were examined on the actinic mask imaging system, SHARP, at Lawrence Berkeley National Laboratory. Also, a quantitative phase retrieval algorithm based on the Weak Object Transfer Function was applied to the measured through-focus aerial images to examine the amplitude and phase of the defects. The accuracy of the algorithm was demonstrated by comparing the results of measurements using a phase contrast zone plate and a standard zone plate. Using partially coherent illumination to measure frequencies that would otherwise fall outside the numerical aperture (NA), it was shown that some defects are smaller than the conventional resolution of the microscope. We found that the programmed defects of various sizes were measured and shown to have both an amplitude and a phase component that the algorithm is able to recover.

  10. Premelting at Defects Within Bulk Colloidal Crystals

    NASA Astrophysics Data System (ADS)

    Alsayed, A. M.; Islam, M. F.; Zhang, J.; Collings, P. J.; Yodh, A. G.

    2005-08-01

    Premelting is the localized loss of crystalline order at surfaces and defects at temperatures below the bulk melting transition. It can be thought of as the nucleation of the melting process. Premelting has been observed at the surfaces of crystals but not within. We report observations of premelting at grain boundaries and dislocations within bulk colloidal crystals using real-time video microscopy. The crystals are equilibrium close-packed, three-dimensional colloidal structures made from thermally responsive microgel spheres. Particle tracking reveals increased disorder in crystalline regions bordering defects, the amount of which depends on the type of defect, distance from the defect, and particle volume fraction. Our observations suggest that interfacial free energy is the crucial parameter for premelting in colloidal and atomic-scale crystals.

  11. Nanoparticle Solubility in Liquid Crystalline Defects

    NASA Astrophysics Data System (ADS)

    Whitmer, Jonathan K.; Armas-Perez, Julio C.; Joshi, Abhijeet A.; Roberts, Tyler F.; de Pablo, Juan J.

    2013-03-01

    Liquid crystalline materials often incorporate regions (defects) where the orientational ordering present in the bulk phase is disrupted. These include point hedgehogs, line disclinations, and domain boundaries. Recently, it has been shown that defects will accumulate impurities such as small molecules, monomer subunits or nanoparticles. Such an effect is thought to be due to the alleviation of elastic stresses within the bulk phase, or to a solubility gap between a nematic phase and the isotropic defect core. This presents opportunities for encapsulation and sequestration of molecular species, in addition to the formation of novel structures within a nematic phase through polymerization and nanoparticle self-assembly. Here, we examine the solubility of nanoparticles within a coarse-grained liquid crystalline phase and demonstrate the effects of nanoparticle size and surface interactions in determining sequestration into defect regions.

  12. Residual Defect Density in Random Disks Deposits

    PubMed Central

    Topic, Nikola; Pöschel, Thorsten; Gallas, Jason A. C.

    2015-01-01

    We investigate the residual distribution of structural defects in very tall packings of disks deposited randomly in large channels. By performing simulations involving the sedimentation of up to 50 × 109 particles we find all deposits to consistently show a non-zero residual density of defects obeying a characteristic power-law as a function of the channel width. This remarkable finding corrects the widespread belief that the density of defects should vanish algebraically with growing height. A non-zero residual density of defects implies a type of long-range spatial order in the packing, as opposed to only local ordering. In addition, we find deposits of particles to involve considerably less randomness than generally presumed. PMID:26235809

  13. Defect-enhanced nematic surface order reconstruction

    NASA Astrophysics Data System (ADS)

    Ambrožič, Milan; Kralj, Samo; Virga, Epifanio G.

    2007-03-01

    Within the Landau-de Gennes phenomenological theory, we study the influence of an applied electric field with average strength Ea on the position of a nematic line defect with topological charge M=±(1)/(2) in a hybrid cell. We explore the biaxial structure of the defect core and we describe its expulsion from the cell upon increasing Ea . We show that prior to the expulsion the defect core displays dramatic changes for strong enough surface anchorings. At a critical value of Ea , the core broadens and merges into a surface layer with a large biaxiality. This transition corresponds to the reconstruction of the nematic order already observed in the bulk in response to an applied electric field. A similar order reconstruction could take place even in the absence of defects, but at a higher threshold.

  14. Neutron-induced defects in optical fibers

    NASA Astrophysics Data System (ADS)

    Rizzolo, S.; Morana, A.; Cannas, M.; Bauer, S.; Perisse, J.; Mace, J.-R.; Boscaino, R.; Boukenter, A.; Ouerdane, Y.; Nacir, B.; Girard, S.

    2014-10-01

    We present a study on 0.8 MeV neutron-induced defects up to fluences of 1017 n/cm2 in fluorine doped optical fibers by using electron paramagnetic resonance, optical absorption and confocal micro-luminescence techniques. Our results allow to address the microscopic mechanisms leading to the generation of Silica-related point-defects such as E', H(I), POR and NBOH Centers.

  15. Neutron-induced defects in optical fibers

    SciTech Connect

    Rizzolo, S.; Morana, A.; Boukenter, A.; Ouerdane, Y.; Girard, S.; Cannas, M.; Boscaino, R.; Bauer, S.; Perisse, J.; Mace, J-R.; Nacir, B.

    2014-10-21

    We present a study on 0.8 MeV neutron-induced defects up to fluences of 10{sup 17} n/cm{sup 2} in fluorine doped optical fibers by using electron paramagnetic resonance, optical absorption and confocal micro-luminescence techniques. Our results allow to address the microscopic mechanisms leading to the generation of Silica-related point-defects such as E', H(I), POR and NBOH Centers.

  16. Defect characterization in the diamond cutting tools

    SciTech Connect

    Zeren, Muzaffer . E-mail: zeren@kou.edu.tr; Karagoez, Sadi

    2006-08-15

    In this study, a general defect characterization in the diamond cutting tools used in natural stone cutting has been investigated. Transverse rupture tests were carried out with different matrix and diamond compositions. In these defect characterization studies on diamond cutting tool materials various microstructural analyses were performed using the techniques of light microscopy (LM), scanning electron microscopy (SEM), energy-dispersed X-ray spectrography (EDX) and image analysis (IA)

  17. Reconstructing the extended nasal tip defect.

    PubMed

    Mobley, Steven

    2013-10-01

    Reconstruction of large facial defects requires surgical skill, an understanding of engineering principles, an artistic eye, and patience to design the most elegant solution for each patient. Extended nasal tip defects, which may involve additional facial subunits, require even more thoughtful analysis and planning. Reconstructive surgeons need to be aware of the pros and cons of various options for flaps, the use of a delay stage, and sequencing and scheduling of staged operations to achieve an optimal outcome. PMID:24037937

  18. Defect structure of web silicon ribbon

    NASA Technical Reports Server (NTRS)

    Cunningham, B.; Strunk, H.; Ast, D.

    1980-01-01

    The results of a preliminary study of two dendritic web samples are presented. The structure and electrical activity of the defects in the silicon webs were studied. Optical microscopy of chemically etched specimens was used to determine dislocation densities. Samples were mechanically polished, then Secco etched for approximately 5 minutes. High voltage transmission electron microscopy was used to characterize the crystallographic nature of the defects.

  19. Topological defects with long-range interactions

    NASA Astrophysics Data System (ADS)

    Mello, B. A.; González, J. A.; Guerrero, L. E.; López-Atencio, E.

    1998-07-01

    We investigate a modified sine-Gordon equation which possesses soliton solutions with long-range interaction. We introduce a generalized version of the Ginzburg-Landau equation which supports long-range topological defects in D = 1 and D > 1. The interaction force between the defects decays so slowly that it is possible to enter the non-extensivity regime. These results can be applied to non-equilibrium systems, pattern formation and growth models.

  20. INNOVATIVE EDDY CURRENT PROBE FOR MICRO DEFECTS

    SciTech Connect

    Santos, Telmo G.; Vilaca, Pedro; Quintino, Luisa; Santos, Jorge dos; Rosado, Luis

    2010-02-22

    This paper reports the development of an innovative eddy current (EC) probe, and its application to micro-defects on the root of the Friction Stir Welding (FSW). The new EC probe presents innovative concept issues, allowing 3D induced current in the material, and a lift-off independence. Validation experiments were performed on aluminium alloys processed by FSW. The results clearly show that the new EC probe is able to detect and sizing surface defects about 60 microns depth.

  1. Innovative Eddy Current Probe for Micro Defects

    NASA Astrophysics Data System (ADS)

    Santos, Telmo G.; Vilaça, Pedro; dos Santos, Jorge; Quintino, Luísa; Rosado, Luís

    2010-02-01

    This paper reports the development of an innovative eddy current (EC) probe, and its application to micro-defects on the root of the Friction Stir Welding (FSW). The new EC probe presents innovative concept issues, allowing 3D induced current in the material, and a lift-off independence. Validation experiments were performed on aluminium alloys processed by FSW. The results clearly show that the new EC probe is able to detect and sizing surface defects about 60 microns depth.

  2. EUV actinic defect inspection and defect printability at the sub-32 nm half pitch

    SciTech Connect

    Huh, Sungmin; Kearney, Patrick; Wurm, Stefan; Goodwin, Frank; Han, Hakseung; Goldberg, Kenneth; Mochi, Iacopp; Gullikson, Eric M.

    2009-08-01

    Extreme ultraviolet (EUV) mask blanks with embedded phase defects were inspected with a reticle actinic inspection tool (AIT) and the Lasertec M7360. The Lasertec M7360, operated at SEMA TECH's Mask Blank Development Center (MBDC) in Albany, NY, has a sensitivity to multilayer defects down to 40-45 nm, which is not likely sufficient for mask blank development below the 32 nm half-pitch node. Phase defect printability was simulated to calculate the required defect sensitivity for a next generation blank inspection tool to support reticle development for the sub-32 nm half-pitch technology node. Defect mitigation technology is proposed to take advantage of mask blanks with some defects. This technology will reduce the cost of ownership of EUV mask blanks. This paper will also discuss the kind of infrastructure that will be required for the development and mass production stages.

  3. Printability of native blank defects and programmed defects and their stack structures

    NASA Astrophysics Data System (ADS)

    Kwon, Hyuk Joo; Harris-Jones, Jenah; Teki, Ranganath; Cordes, Aaron; Nakajima, Toshio; Mochi, Iacopo; Goldberg, Kenneth A.; Yamaguchi, Yuya; Kinoshita, Hiroo

    2011-11-01

    We describe the characterization of native phase defects in the manufacturing of extreme ultraviolet (EUV) mask blanks using the state-of-the-art mask metrology equipment in SEMATECH's Mask Blank Development Center (MBDC). We used commercially available quartz substrates and deposited Mo/Si multilayers on the substrates to characterize phase defects. We also prepared programmed defects of various dimensions using e-beam patterning technology on which multilayers were deposited. Transmission electron microscopy (TEM) was used to study multilayer profile changes, while SEMATECH's actinic inspection tool (AIT) was used to image defects and predict their printability. Defect images at different focal depths of the AIT are correlated to TEM cross sections and atomic force microscopy (AFM) dimensions. The printability of native and programmed defects was also investigated.

  4. Topological Defects in Liquid Crystals: Studying the Correlation between Defects and Curvature

    NASA Astrophysics Data System (ADS)

    Melton, Charles

    2015-03-01

    Topological defects have recently been the subject of many fascinating studies in soft condensed matter physics. In particular, linking the evolution of topological defects to curvature changes has been a focus, leading possible applications in the areas such as cosmetics, pharmaceuticals, and electronics. In this study, defects in nematic liquid crystal droplets are investigated via laboratory and theoretical techniques. Nematic liquid crystal defects are reproduced via Monte Carlo simulations using a modified 2D XY-Model Hamiltonian. The simulation is performed on a curved surface to replicate a nematic droplet and examine possible defect configurations. To complement this theoretical work, we have trapped nematic droplets inside a dual-beam optical trap. This system allows controllable non-contact droplet deformation on a microscope based platform. Future work will focus on using the trap to stretch nematic droplets, correlating the changing topological defects with theoretical predictions.

  5. Reduction in Defect Content of ODS Alloys

    SciTech Connect

    Ritherdon, J

    2001-05-15

    The work detailed within this report is a continuation of earlier work carried out under contract number 1DX-SY382V. The earlier work comprises a literature review of the sources and types of defects found principally in Fe-based ODS alloys as well as experimental work designed to identify defects in the prototype ODS-Fe{sub 3}Al alloy, deduce their origins and to recommend methods of defect reduction. The present work is an extension of the experimental work already reported and concentrates on means of reduction of defects already identified rather than the search for new defect types. This report also includes results gathered during powder separation trials, conducted by the University of Groningen, Netherlands and coordinated by the University of Liverpool, involving the separation of different metallic powders in terms of their differing densities. The scope and objectives of the present work were laid out in the technical proposal ''Reduction in Defect Content in ODS Alloys-III''. All the work proposed in the ''Statement of Work'' section of the technical proposal has been carried out and all work extra to the ''Statement of Work'' falls within the context of an ODS-Fe{sub 3}Al alloy of improved overall quality and potential creep performance in the consolidated form. The outturn of the experimental work performed is reported in the following sections.

  6. [Polycyclic aromatic hydrocarbons exposure and birth defects].

    PubMed

    Lin, S S; Huang, Y; Wang, C Y; Ren, A G

    2016-06-01

    Birth defects are one of the most common adverse birth outcomes, which create a heavy economic burden to the country, society and family. And they are also one of the biggest problems facing public health today. Polycyclic aromatic hydrocarbons (PAHs) are a group of toxic pollutants existing in the environment widely, resulting from incomplete organic matter combustion, and can be taken into the body through various ways including the digestive tract, respiratory tract and so on. Recent researches suggest that the exposure of PAHs may be associated with various birth defects, while the special mechanism isn't very clear. This paper is a review of the relationship between PAHs and birth defects from the aspects of epidemiological data, experimental evidence on animals, which indicates that exposure of PAHs during pregnancy may be associated with birth defects including congenital heart defects, neural tube defects and cleft lip/plate. Furthermore, we explored the possible mechanism, including oxidative stress, oxidative damage and the changes of signal transduction pathway in order to provide some recommendations and suggestions on the future work. PMID:27256742

  7. Intrinsic structural defects in monolayer molybdenum disulfide

    SciTech Connect

    Zhou, Wu; Idrobo Tapia, Juan C

    2013-01-01

    Monolayer molybdenum disulfide (MoS2) is a two-dimensional direct band gap semiconductor with distinctive mechanical, electronic, optical and chemical properties that can be utilized for novel nanoelectronics and optoelectronics devices. The performance of these electronic devices strongly depends on the quality and defect morphology of the MoS2 layers. Yet, little is known about the atomic structure of defects present in monolayer MoS2 and their influences on the material properties. Here we provide a systematic study of various intrinsic structural defects, including point defects, grain boundaries, and edges, in chemical vapor phase grown monolayer MoS2 via direct atomic resolution imaging, and explore their energy landscape and electronic properties using first-principles calculations. We discover that one-dimensional metallic wires can be created via two different types of 60 grain boundaries consisting of distinct 4-fold ring chains. A new type of edge reconstruction, representing a transition state during growth, was also identified, providing insights into the material growth mechanism. The atomic scale study of structural defects presented here brings new opportunities to tailor the properties of MoS2 via controlled synthesis and defect engineering.

  8. A novel inspection system for cosmetic defects

    NASA Astrophysics Data System (ADS)

    Hazra, S.; Roy, R.; Williams, D.; Aylmore, R.; Hollingdale, D.

    2013-12-01

    The appearance of automotive skin panels creates desirability for a product and differentiates it from the competition. Because of the importance of skin panels, considerable care is taken in minimizing defects such as the 'hollow' defect that occur around door-handle depressions. However, the inspection process is manual, subjective and time-consuming. This paper describes the development of an objective and inspection scheme for the 'hollow' defect. In this inspection process, the geometry of a panel is captured using a structured lighting system. The geometry data is subsequently analyzed by a purpose-built wavelet-based algorithm to identify the location of any defects that may be present and to estimate the perceived severity of the defects without user intervention. This paper describes and critically evaluates the behavior of this physically-based algorithm on an ideal and real geometry and compares its result to an actual audit. The results show that the algorithm is capable of objectively locating and classifying 'hollow' defects in actual panels.

  9. Quality metrics for product defectiveness at KCD

    SciTech Connect

    Grice, J.V.

    1993-07-01

    Metrics are discussed for measuring and tracking product defectiveness at AlliedSignal Inc., Kansas City Division (KCD). Three new metrics, the metric (percent defective) that preceded the new metrics, and several alternatives are described. The new metrics, Percent Parts Accepted, Percent Parts Accepted Trouble Free, and Defects Per Million Observations, (denoted by PPA, PATF, and DPMO, respectively) were implemented for KCD-manufactured product and purchased material in November 1992. These metrics replace the percent defective metric that had been used for several years. The PPA and PATF metrics primarily measure quality performance while DPMO measures the effects of continuous improvement activities. The new metrics measure product quality in terms of product defectiveness observed only during the inspection process. The metrics were originally developed for purchased product and were adapted to manufactured product to provide a consistent set of metrics plant- wide. The new metrics provide a meaningful tool to measure the quantity of product defectiveness in terms of the customer`s requirements and expectations for quality. Many valid metrics are available and all will have deficiencies. These three metrics are among the least sensitive to problems and are easily understood. They will serve as good management tools for KCD in the foreseeable future until new flexible data systems and reporting procedures can be implemented that can provide more detailed and accurate metric computations.

  10. Fluorescent Defects in Hexagonal Boron Nitride

    NASA Astrophysics Data System (ADS)

    Exarhos, Annemarie L.; Oser, Kameron; Hopper, David A.; Grote, Richard R.; Bassett, Lee C.

    Mono- and few-layer hexagonal boron nitride (h-BN) can host defects whose electronic states lie deep within the bandgap, similar to the nitrogen-vacancy color center in bulk diamond. Here, we study defect creation in h-BN through irradiation and thermal annealing. We employ confocal photoluminescence (PL) imaging and spectroscopy under various excitation energies on both supported and suspended h-BN to identify and characterize the emission of isolated defect centers. Polarization- and temperature-dependent measurements of the observed PL are used to map out the electronic structure of the defects, enabling optical control of fluorescent defects in h-BN. This knowledge, coupled with the spatial confinement to 2D and the unique electrical, optical, and mechanical properties of h-BN, will enable the use of these defects for quantum sensing and other applications in quantum information processing. Work supported by the ARO (W911NF-15-1-0589) and NSF MRSEC (DMR-1120901).

  11. Simulation of EUV multilayer mirror buried defects

    NASA Astrophysics Data System (ADS)

    Brukman, Matthew J.; Deng, Yunfei; Neureuther, Andrew R.

    2000-07-01

    A new interface has been created to link existing deposition/etching and electromagnetic simulation software, allowing the user to program deposition and etching conditions and then find the reflective properties of the resultant structure. The application studied in this paper is the problem of three-dimensional defects which become buried during fabrication of multilayer mirrors for extreme ultraviolet lithography. The software link reads in surface information in the form of linked triangles, determines all nodes within the triangles, and then creates nodes lying between triangles of different layers to create a 3- dimensional inhomogeneous matrix containing the materials' indices of refraction. This allows etching and depositions to be input into SAMPLE-3D, a multi-surface topology to be generated, and then the electromagnetic properties of the structure to be assessed with TEMPEST. This capability was used to study substrate defects in multilayer mirrors by programming a defect and then sputter-depositing some forty layers on top of the defect. Specifically examined was how the topography depended on sputter conditions and determined the defects' impact on the mirrors' imaging properties. While this research was focused on application to EUV lithography, the general technique may be extended to other optical processes such as alignment and mask defects.

  12. A theoretical study of intrinsic point defects and defect clusters in magnesium aluminate spinel.

    PubMed

    Gilbert, C A; Smith, R; Kenny, S D; Murphy, S T; Grimes, R W; Ball, J A

    2009-07-01

    Point and small cluster defects in magnesium aluminate spinel have been studied from a first principles viewpoint. Typical point defects that occur during collision cascade simulations are cation anti-site defects, which have a small formation energy and are very stable, O and Mg split interstitials and vacancies. Isolated Al interstitials were found to be energetically unfavourable but could occur as part of a split Mg-Al pair or as a three atom-three vacancy Al 'ring' defect, previously observed in collision cascades using empirical potentials. The structure and energetics of the defects were investigated using density functional theory (DFT) and the results compared to simulations using empirical fixed charge potentials. Each point defect was studied in a variety of supercell sizes in order to ensure convergence. It was found that empirical potential simulations significantly overestimate formation energies, but that the type and relative stability of the defects are well predicted by the empirical potentials both for point defects and small defect clusters. PMID:21828490

  13. A theoretical study of intrinsic point defects and defect clusters in magnesium aluminate spinel

    NASA Astrophysics Data System (ADS)

    Gilbert, C. A.; Smith, R.; Kenny, S. D.; Murphy, S. T.; Grimes, R. W.; Ball, J. A.

    2009-07-01

    Point and small cluster defects in magnesium aluminate spinel have been studied from a first principles viewpoint. Typical point defects that occur during collision cascade simulations are cation anti-site defects, which have a small formation energy and are very stable, O and Mg split interstitials and vacancies. Isolated Al interstitials were found to be energetically unfavourable but could occur as part of a split Mg-Al pair or as a three atom-three vacancy Al 'ring' defect, previously observed in collision cascades using empirical potentials. The structure and energetics of the defects were investigated using density functional theory (DFT) and the results compared to simulations using empirical fixed charge potentials. Each point defect was studied in a variety of supercell sizes in order to ensure convergence. It was found that empirical potential simulations significantly overestimate formation energies, but that the type and relative stability of the defects are well predicted by the empirical potentials both for point defects and small defect clusters.

  14. Automated defect review of the wafer bevel with a defect review scanning electron microscope

    NASA Astrophysics Data System (ADS)

    McGarvey, Steve; Kanezawa, Masakazu

    2009-03-01

    One of the few remaining bastions of non-regulated Integrated Circuit defectivity is the wafer bevel. Recent internal Integrated Circuit Manufacturing studies have suggested that the edge bevel may be responsible for as much as a two to three percent yield loss during a defect excursion on the manufacturing line and a one to two percent yield loss during ongoing wafer manufacturing. A new generation of defect inspection equipment has been introduced to the Research and Development, Integrated Circuit, MEM's and Si wafer manufacturing markets that has imparted the ability for the end equipment user to detect defects located on the bevel of the wafer. The inherent weakness of the current batch of wafer bevel inspection equipment is the lack of automatic discrete defect classification data into multiple, significant classification bins and the lack of discrete elemental analysis data. Root cause analysis is based on minimal discrete defect analysis as a surrogate for a statistically valid sampling of defects from the bevel. This paper provides a study of the methods employed with a Hitachi RS-5500EQEQ Defect Review Scanning Electron Microscope (DRSEM) to automatically capture high resolution/high magnification images and collect elemental analysis on a statistically valid sample of the discrete defects that were located by a bevel inspection system.

  15. USE OF BIOCERAMICS IN FILLING BONE DEFECTS

    PubMed Central

    Garrido, Carlos Antõnio; Sampaio, Tania Clarete Fonseca Vieira Sales

    2015-01-01

    Objective: To present the results from using biological ceramics for filling bone defects resulting from post-traumatic or orthopedic injuries. Methods: Thirty-six patients with bone defects caused by trauma or orthopedic injury were evaluated. Nineteen patients were male (52.8%) and 17 were female (47.2%). Their ages ranged from 19 to 84 years, with a mean of 45.7 years and median of 37 years. Only patients with defects that required at least five grams of biological ceramic were included. Eighteen cases were classified as orthopedic: bone defects were observed in 11 cases of total hip arthroplasty; one case of primary total hip arthroplasty, due to coxarthrosis; five cases of femoral or tibial open wedge osteotomy; and one case of tarsal arthrodesis. There were 18 cases of trauma-related defects; uninfected pseudarthrosis, eight cases; recent fractures of the tibial plateau with compression of the spongy bone, three cases; and exposed fractures treated with external fixators, seven cases. The surgical technique consisted of curetting and debriding the injury until bone suitable for grafting was found. Biological ceramic was then used to fill the defect and some kind of fixation was applied. Results: Among the 36 patients evaluated, it was seen that 35 (97.2%) presented integration of the biological ceramic, while one case of open fracture treated with external fixation had poor integration of the biological ceramic. Conclusion: Treatment of bone defects of orthopedic or post-traumatic etiology using a phosphocalcium ceramic composed of hydroxyapatite was shown to be a practical, effective and safe method. PMID:27022576

  16. Equilibrium defects and concentrations in nickel aluminide

    SciTech Connect

    Bai, B.; Collins, G.S.

    1999-07-01

    Perturbed angular correlation of gamma rays was applied to determine properties of equilibrium defects in B2 NiAl near the stoichiometric composition. Point defects were detected through quadrupole interactions they induce at In probe atoms on the Al sublattice. Well-resolved signals were observed for probe atoms having zero, one or two Ni-vacancies (V{sub Ni}) in the first neighbor shell. The fractions of probes in different sites are analyzed using a thermodynamic model to determine defect properties as follows. The equilibrium high-temperature defect is determined to be the triple defect combination (two V{sub Ni} and one Ni-antisite atom) through the variation of the vacancy concentration with composition and not, for example, the Schottky vacancy pair. The binding enthalpy of V{sub Ni} with a probe atom was determined to be in the range 0.18--0.24 eV. Site fractions were measured for three samples having 50.03, 50.14 and 50.91 at.% Ni at temperatures up to 1300 C. Vacancy concentrations were deduced from the site fractions and binding enthalpy. The equilibrium constant for formation of the triple defect was determined as a function of temperature from the vacancy concentrations and sample compositions. The formation enthalpy was found to be in the range 1.65--1.83 eV, depending on the binding enthalpy. The formation entropy was found to be {minus}3.2(4)k{sub B}. The large, negative value of the formation entropy probably cannot be explained in terms of a binding entropy, and the authors speculate that triple defects harden the B2 lattice, perhaps by disrupting the well-known 1/3 {l{underscore}angle}111{r{underscore}angle} soft mode lattice instability in B2 and bcc materials.

  17. 7 CFR 42.106 - Classifying and recording defects.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Classifying and recording defects. 42.106 Section 42... § 42.106 Classifying and recording defects. (a) Classifying defects. Examine each sample unit for the.... Other defects, not specifically listed, shall be classified according to their effect on the...

  18. 7 CFR 42.106 - Classifying and recording defects.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Classifying and recording defects. 42.106 Section 42... § 42.106 Classifying and recording defects. (a) Classifying defects. Examine each sample unit for the.... Other defects, not specifically listed, shall be classified according to their effect on the...

  19. 7 CFR 42.106 - Classifying and recording defects.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Classifying and recording defects. 42.106 Section 42... § 42.106 Classifying and recording defects. (a) Classifying defects. Examine each sample unit for the.... Other defects, not specifically listed, shall be classified according to their effect on the...

  20. 7 CFR 42.106 - Classifying and recording defects.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Classifying and recording defects. 42.106 Section 42... § 42.106 Classifying and recording defects. (a) Classifying defects. Examine each sample unit for the.... Other defects, not specifically listed, shall be classified according to their effect on the...

  1. 7 CFR 42.106 - Classifying and recording defects.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Classifying and recording defects. 42.106 Section 42... § 42.106 Classifying and recording defects. (a) Classifying defects. Examine each sample unit for the.... Other defects, not specifically listed, shall be classified according to their effect on the...

  2. 7 CFR 51.3416 - Classification of defects.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Classification of defects. 51.3416 Section 51.3416... § 51.3416 Classification of defects. External Defects Defects Maximum allowed for U.S. No. 1 processing... within the vascular ring Hollow Heart or Hollow Heart with Discoloration Area affected not to exceed...

  3. Efficient Co-Replication of Defective Novirhabdovirus

    PubMed Central

    Rouxel, Ronan N.; Mérour, Emilie; Biacchesi, Stéphane; Brémont, Michel

    2016-01-01

    We have generated defective Viral Hemorrhagic Septicemia Viruses (VHSV) which express either the green fluorescent protein (GFP) or a far-red fluorescent protein (mKate) by replacing the genes encoding the nucleoprotein N or the polymerase-associated P protein. To recover viable defective viruses, rVHSV-ΔN-Red and rVHSV-ΔP-Green, fish cells were co-transfected with both deleted cDNA VHSV genomes, together with plasmids expressing N, P and L of the RNA-dependent RNA polymerase. After one passage of the transfected cell supernatant, red and green cell foci were observed. Viral titer reached 107 PFU/mL after three passages. Infected cells were always red and green with the very rare event of single red or green cell foci appearing. To clarify our understanding of how such defective viruses could be so efficiently propagated, we investigated whether (i) a recombination event between both defective genomes had occurred, (ii) whether both genomes were co-encapsidated in a single viral particle, and (iii) whether both defective viruses were always replicated together through a complementation phenomenon or even as conglomerate. To address these hypotheses, genome and viral particles have been fully characterized and, thus, allowing us to conclude that rVHSV-ΔN-Red and rVHSV-ΔP-Green are independent viral particles which could propagate only by simultaneously infecting the same cells. PMID:26959049

  4. Laser intensity modulation by nonabsorbing defects

    SciTech Connect

    Feit, M.D.; Rubenchik, A.M.

    1997-01-01

    Nonabsorbing bulk defects can initiate laser damage in transparent materials. Defects such as voids, microcracks and localized stress concentrations can serve as positive or negative lenses for the incident laser light. The resulting interference pattern between refracted and diffracted light can result in intensity increases on the order of a factor of 2 some distance away from a typical negative microlens, and even larger for a positive microlens. Thus, the initial damage site can be physically removed from the defect which initiates damage. The parameter that determines the strength of such lensing is (Ka){sup 2}{Delta}{epsilon}, where the wavenumber K is 2{pi}/{lambda} linear size of the defect and AF, is the difference in dielectric coefficient between matrix and scatterer. Thus, even a small change in refractive index results in a significant effect for a defect large compared to a wavelength. Geometry is also important. Three dimensional (eg. voids) as well as linear and planar (eg. cracks) microlenses can all have strong effects. The present paper evaluates the intensification due to spherical voids and high refractive index inclusions. We wish to particularly draw attention to the very large intensification that can occur at inclusions.

  5. Laser intensity modulation by nonabsorbing defects

    SciTech Connect

    Feit, M.D., Rubenchik, A.M.

    1996-11-20

    Nonabsorbing defects can lead to laser damage. Defects such as voids, microcracks, and localized stressed concentrations, even if they differ from the surrounding medium only by refractive index, can serve as positive or negative lenses for the incident laser light. The resulting interference pattern between refracted and diffracted light can result in intensity increases on the order of a factor of 2 some distance away from a typical negative microlens, and even larger for a positive microlens. Thus, the initial damage site can be physically removed from the defect which initiates damage. The parameter that determines the strength of such lensing is (Ka){sup 2}{Delta}{epsilon}, where the wavenumber K is 2{pi}/{lambda}, 2a is the linear size of the defect, and {Delta}{epsilon} is the difference in dielectric coefficient between matrix and scatterer. Thus, even a small change in refractive index results in a significant effect for a defect large compared to a wavelength. Geometry is also important. Three dimensional (e.g. voids) as well as linear and planar (e.g. cracks) microlenses can all have strong effects. This paper evaluates intensification due to spherical voids and high refractive index inclusions.

  6. Structure Defect Property Relationships in Binary Intermetallics

    NASA Astrophysics Data System (ADS)

    Medasani, Bharat; Ding, Hong; Chen, Wei; Persson, Kristin; Canning, Andrew; Haranczyk, Maciej; Asta, Mark

    2015-03-01

    Ordered intermetallics are light weight materials with technologically useful high temperature properties such as creep resistance. Knowledge of constitutional and thermal defects is required to understand these properties. Vacancies and antisites are the dominant defects in the intermetallics and their concentrations and formation enthalpies could be computed by using first principles density functional theory and thermodynamic formalisms such as dilute solution method. Previously many properties of the intermetallics such as melting temperatures and formation enthalpies were statistically analyzed for large number of intermetallics using structure maps and data mining approaches. We undertook a similar exercise to establish the dependence of the defect properties in binary intermetallics on the underlying structural and chemical composition. For more than 200 binary intermetallics comprising of AB, AB2 and AB3 structures, we computed the concentrations and formation enthalpies of vacancies and antisites in a small range of stoichiometries deviating from ideal stoichiometry. The calculated defect properties were datamined to gain predictive capabilities of defect properties as well as to classify the intermetallics for their suitability in high-T applications. Supported by the US DOE under Contract No. DEAC02-05CH11231 under the Materials Project Center grant (Award No. EDCBEE).

  7. Li diffusion through doped and defected graphene.

    PubMed

    Das, Deya; Kim, Seungchul; Lee, Kwang-Ryeol; Singh, Abhishek K

    2013-09-28

    We investigate the effect of nitrogen and boron doping on Li diffusion through defected graphene using first principles based density functional theory. While a high energy barrier rules out the possibility of Li- diffusion through the pristine graphene, the barrier reduces with the incorporation of defects. Among the most common defects in pristine graphene, Li diffusion through the divacancy encounters the lowest energy barrier of 1.34 eV. The effect of nitrogen and boron doping on the Li diffusion through doped defected-graphene sheets has been studied. N-doping in graphene with a monovacancy reduces the energy barrier significantly. The barrier reduces with the increasing number of N atoms. On the other hand, for N doped graphene with a divacancy, Li binds in the plane of the sheet, with an enhanced binding energy. The B doping in graphene with a monovacancy leads to the enhancement of the barrier. However, in the case of B-doped graphene with a divacancy, the barrier reduces to 1.54 eV, which could lead to good kinetics. The barriers do not change significantly with B concentration. Therefore, divacancy, B and N doped defected graphene has emerged as a better alternative to pristine graphene as an anode material for Li ion battery. PMID:23925460

  8. Defects of thiamine transport and metabolism.

    PubMed

    Brown, Garry

    2014-07-01

    Thiamine, in the form of thiamine pyrophosphate, is a cofactor for a number of enzymes which play important roles in energy metabolism. Although dietary thiamine deficiency states have long been recognised, it is only relatively recently that inherited defects in thiamine uptake, activation and the attachment of the active cofactor to target enzymes have been described, and the underlying genetic defects identified. Thiamine is transported into cells by two carriers, THTR1 and THTR2, and deficiency of these results in thiamine-responsive megaloblastic anaemia and biotin-responsive basal ganglia disease respectively. Defective synthesis of thiamine pyrophosphate has been found in a small number of patients with episodic ataxia, delayed development and dystonia, while impaired transport of thiamine pyrophosphate into the mitochondrion is associated with Amish lethal microcephaly in most cases. In addition to defects in thiamine uptake and metabolism, patients with pyruvate dehydrogenase deficiency and maple syrup urine disease have been described who have a significant clinical and/or biochemical response to thiamine supplementation. In these patients, an intrinsic structural defect in the target enzymes reduces binding of the cofactor and this can be overcome at high concentrations. In most cases, the clinical and biochemical abnormalities in these conditions are relatively non-specific, and the range of recognised presentations is increasing rapidly at present as new patients are identified, often by genome sequencing. These conditions highlight the value of a trial of thiamine supplementation in patients whose clinical presentation falls within the spectrum of documented cases. PMID:24789339

  9. Efficient Co-Replication of Defective Novirhabdovirus.

    PubMed

    Rouxel, Ronan N; Mérour, Emilie; Biacchesi, Stéphane; Brémont, Michel

    2016-03-01

    We have generated defective Viral Hemorrhagic Septicemia Viruses (VHSV) which express either the green fluorescent protein (GFP) or a far-red fluorescent protein (mKate) by replacing the genes encoding the nucleoprotein N or the polymerase-associated P protein. To recover viable defective viruses, rVHSV-ΔN-Red and rVHSV-ΔP-Green, fish cells were co-transfected with both deleted cDNA VHSV genomes, together with plasmids expressing N, P and L of the RNA-dependent RNA polymerase. After one passage of the transfected cell supernatant, red and green cell foci were observed. Viral titer reached 10⁷ PFU/mL after three passages. Infected cells were always red and green with the very rare event of single red or green cell foci appearing. To clarify our understanding of how such defective viruses could be so efficiently propagated, we investigated whether (i) a recombination event between both defective genomes had occurred, (ii) whether both genomes were co-encapsidated in a single viral particle, and (iii) whether both defective viruses were always replicated together through a complementation phenomenon or even as conglomerate. To address these hypotheses, genome and viral particles have been fully characterized and, thus, allowing us to conclude that rVHSV-ΔN-Red and rVHSV-ΔP-Green are independent viral particles which could propagate only by simultaneously infecting the same cells. PMID:26959049

  10. Defects in Germinal Center Selection in SLE

    PubMed Central

    Woods, Megan; Zou, Yong-Rui; Davidson, Anne

    2015-01-01

    Germinal centers (GCs) are the primary site at which clonal expansion and affinity maturation of B cells occur. B cells encounter antigen and receive T cell help in the GC light zone (LZ) and then migrate to the dark zone where they proliferate and undergo somatic mutation before cycling back to the LZ for further rounds of selection. Tolerance to autoantigens is frequently lost de novo as GC B cells undergo class switching and somatic mutation. This loss of tolerance is regulated by a variety of mechanisms including cell death, failure to compete for T cell help, and failure to differentiate into effector cells. Systemic lupus erythematosus (SLE) is characterized by loss of tolerance to nucleic acid antigens. While defects in tolerance occur in the naïve repertoire of SLE patients, pathogenic autoantibodies also arise in the GC by somatic mutation from non-autoreactive precursors. Several B cell defects contribute to the loss of GC tolerance in SLE, including polymorphisms of genes encoded by the Sle1 locus, excess TLR7 signaling, defects in FcRIIB expression, or defects of B cell apoptosis. Extrinsic soluble factors, such as Type-1 IFN and B cell-activating factor, or an increased number of T follicular helper cells in the GC also alter B cell-negative selection. Finally, defects in clearance of apoptotic debris within the GC result in BCR-mediated internalization of nucleic acid containing material and stimulation of autoantibody production by endosomal TLR-driven mechanisms. PMID:26322049

  11. Lattice Defects in the Kitaev Honeycomb Model.

    PubMed

    Brennan, John; Vala, Jiří

    2016-05-19

    The Kitaev honeycomb lattice system is an important model of topological materials whose phase diagram exhibits both abelian and non-abelian topological phases. The latter, a so-called Ising phase, is related to topological superconductors. Its quasiparticle excitations, which are formed by Majorana fermions attached to vortices, show non-abelian fractional statistics and are known as Ising anyons. We investigate dislocation defects in the Ising phase of the Kitaev honeycomb model. After introducing them to the system, we accordingly generalize our solution of this model to the situation with the defects. The important part of this effort is developing an appropriate Jordan-Wigner fermionization procedure. It is expected that the presence of defects manifests itself by the formation of fermionic zero-energy modes around the defect end points. We numerically confirm this expectation and further investigate properties of these modes. The computational potential of our technique is demonstrated for both diagonalization and dynamical simulations. The latter focuses on the process of fusion of the vortex zero-energy modes with the Majorana fermions attached to the defect. This process simulates fusion of non-abelian Ising anyons. PMID:26886150

  12. Development of defects detection in gluing glass

    NASA Astrophysics Data System (ADS)

    Wu, Zongming; Yang, Wei; Fan, Tianquan

    2012-09-01

    The defects engendering in the process of glass gluing are mainly flaws and delaminations which will reduce the stability and processing availability of the optical component. How to detect these defects has become a technical problem for a long time. Several Non-Destructive Test (NDT) methods such as ultrasonic C-scan, bubble tester and infrared thermography are effective in inspection of it at present. In this paper, these three techniques' detection principle, advantages and disadvantages are introduced. On the basis of detection demands, photothermal radiometry that it has become a powerful tool to detect subsurface defects in composites because of its non-contact and highly sensitivity is used to detect defects in the gluing process of glass for the first time. The basic idea that glass-layer transmits the spectrum and the spectrum energy is absorbed by glue-layer is also put forward creatively. By monitoring the temperature variation of glue-layer in time domain using infrared thermal imager, the defects can be discovered.

  13. Algorithm for Generating Defective Graphene Sheets.

    PubMed

    Nutt, David R; Weller, Hilary

    2009-07-14

    An algorithm is presented for the generation of molecular models of defective graphene fragments, containing a majority of 6-membered rings with a small number of 5- and 7-membered rings as defects. The structures are generated from an initial random array of points in 2D space, which are then subject to Delaunay triangulation. The dual of the triangulation forms a Voronoi tessellation of polygons with a range of ring sizes. An iterative cycle of refinement, involving deletion and addition of points followed by further triangulation, is performed until the user-defined criteria for the number of defects are met. The array of points and connectivities are then converted to a molecular structure and subject to geometry optimization using a standard molecular modeling package to generate final atomic coordinates. On the basis of molecular mechanics with minimization, this automated method can generate structures, which conform to user-supplied criteria and avoid the potential bias associated with the manual building of structures. One application of the algorithm is the generation of structures for the evaluation of the reactivity of different defect sites. Ab initio electronic structure calculations on a representative structure indicate preferential fluorination close to 5-ring defects. PMID:26610012

  14. Determining the Critcial Size of EUV Mask Substrate Defects

    SciTech Connect

    Mccall, Monnikue M; Han, Hakseung; Cho, Wonil; Goldberg, Kenneth; Gullikson, Eric; Jeon, Chan-Uk; Wurm, Stefan

    2008-02-28

    Determining the printability of substrate defects beneath the extreme ultraviolet (EUV) reflecting multilayer stack is an important issue in EUVL lithography. Several simulation studies have been performed in the past to determine the tolerable defect size on EUV mask blank substrates but the industry still has no exact specification based on real printability tests. Therefore, it is imperative to experimentally determine the printability of small defects on a mask blanks that are caused by substrate defects using direct printing of programmed substrate defect in an EUV exposure tool. SEMATECH fabricated bump type program defect masks using standard electron beam lithography and performed printing tests with the masks using an EUV exposure tool. Defect images were also captured using SEMATECH's Berkeley Actinic Imaging Tool in order to compare aerial defect images with secondary electron microscope images from exposed wafers. In this paper, a comprehensive understanding of substrate defect printability will be presented and printability specifications of EUV mask substrate defects will be discussed.

  15. A practical approach for modeling EUVL mask defects

    SciTech Connect

    Gullikson, E.M.; Cerjan, C.; Stearns, D.J.; Mirkarimi, P.B.; Sweeney, D.W.

    2001-06-01

    An approximate method is proposed to calculate the EUV scattering from a defect within a multilayer coating. In this single surface approximation (SSA) the defective multilayer structure is replaced by a single reflecting surface with the shape of the top surface of the multilayer. The range of validity of this approximation has been investigated for Gaussian line defects using 2D finite-difference-time-domain simulations. The SSA is found to be valid for sufficiently low aspect ratio defects such as those expected for the critical defects nucleated by particles on the mask substrate. The critical EUVL defect size is calculated by combining the SSA with a multilayer growth model and aerial image simulations. Another approximate method for calculating the aerial image of an unresolved defect is also discussed. Although the critical substrate defects may be larger than the resolution of higher NA cameras, the point defect approximation provides a useful framework for understanding the printability of a wide range of defects.

  16. Determining the critical size of EUV mask substrate defects

    SciTech Connect

    Goldberg, Kenneth A.; Gullikson, Eric M.; Han, Hakseung; Cho, Wonil; Jeon, Chan-Uk; Wurm, Stefan

    2008-05-26

    Determining the printability of substrate defects beneath the extreme ultraviolet (EUV) reflecting multilayer stack is an important issue in EUVL lithography. Several simulation studies have been performed in the past to determine the tolerable defect size on EUV mask blank substrates but the industry still has no exact specification based on real printability tests. Therefore, it is imperative to experimentally determine the printability of small defects on a mask blanks that are caused by substrate defects using direct printing of programmed substrate defect in an EUV exposure tools. SEMATECH fabricated bump type program defect masks using standard electron beam lithography and performed printing tests with the masks using an EUV exposure tool. Defect images were also captured using SEMATECH's Berkeley Actinic Imaging Tool in order to compare aerial defect images with secondary electron microscope images from exposed wafers. In this paper, a comprehensive understanding of substrate defect printability will be presented and printability specifications of EUV mask substrate defects will be discussed.

  17. 48 CFR 1615.407-1 - Rate reduction for defective pricing or defective cost or pricing data.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... defective pricing or defective cost or pricing data. 1615.407-1 Section 1615.407-1 Federal Acquisition... CONTRACTING METHODS AND CONTRACT TYPES CONTRACTING BY NEGOTIATION Contract Pricing 1615.407-1 Rate reduction for defective pricing or defective cost or pricing data. The clause set forth in section...

  18. 48 CFR 1652.215-70 - Rate Reduction for Defective Pricing or Defective Cost or Pricing Data.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Defective Pricing or Defective Cost or Pricing Data. 1652.215-70 Section 1652.215-70 Federal Acquisition... CLAUSES AND FORMS CONTRACT CLAUSES Texts of FEHBP Clauses 1652.215-70 Rate Reduction for Defective Pricing or Defective Cost or Pricing Data. As prescribed in 1615.407-1, the following clause shall...

  19. 48 CFR 1615.407-1 - Rate reduction for defective pricing or defective cost or pricing data.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... defective pricing or defective cost or pricing data. 1615.407-1 Section 1615.407-1 Federal Acquisition... CONTRACTING METHODS AND CONTRACT TYPES CONTRACTING BY NEGOTIATION Contract Pricing 1615.407-1 Rate reduction for defective pricing or defective cost or pricing data. The clause set forth in section...

  20. 48 CFR 1652.215-70 - Rate Reduction for Defective Pricing or Defective Cost or Pricing Data.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Defective Pricing or Defective Cost or Pricing Data. 1652.215-70 Section 1652.215-70 Federal Acquisition... CLAUSES AND FORMS CONTRACT CLAUSES Texts of FEHBP Clauses 1652.215-70 Rate Reduction for Defective Pricing or Defective Cost or Pricing Data. As prescribed in 1615.407-1, the following clause shall...

  1. 48 CFR 1615.407-1 - Rate reduction for defective pricing or defective cost or pricing data.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... defective pricing or defective cost or pricing data. 1615.407-1 Section 1615.407-1 Federal Acquisition... CONTRACTING METHODS AND CONTRACT TYPES CONTRACTING BY NEGOTIATION Contract Pricing 1615.407-1 Rate reduction for defective pricing or defective cost or pricing data. The clause set forth in section...

  2. 48 CFR 1615.407-1 - Rate reduction for defective pricing or defective cost or pricing data.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... defective pricing or defective cost or pricing data. 1615.407-1 Section 1615.407-1 Federal Acquisition... CONTRACTING METHODS AND CONTRACT TYPES CONTRACTING BY NEGOTIATION Contract Pricing 1615.407-1 Rate reduction for defective pricing or defective cost or pricing data. The clause set forth in section...

  3. 48 CFR 1652.215-70 - Rate Reduction for Defective Pricing or Defective Cost or Pricing Data.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Defective Pricing or Defective Cost or Pricing Data. 1652.215-70 Section 1652.215-70 Federal Acquisition... CLAUSES AND FORMS CONTRACT CLAUSES Texts of FEHBP Clauses 1652.215-70 Rate Reduction for Defective Pricing or Defective Cost or Pricing Data. As prescribed in 1615.407-1, the following clause shall...

  4. 48 CFR 1652.215-70 - Rate Reduction for Defective Pricing or Defective Cost or Pricing Data.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Defective Pricing or Defective Cost or Pricing Data. 1652.215-70 Section 1652.215-70 Federal Acquisition... CLAUSES AND FORMS CONTRACT CLAUSES Texts of FEHBP Clauses 1652.215-70 Rate Reduction for Defective Pricing or Defective Cost or Pricing Data. As prescribed in 1615.407-1, the following clause shall...

  5. 48 CFR 1615.407-1 - Rate reduction for defective pricing or defective cost or pricing data.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... defective pricing or defective cost or pricing data. 1615.407-1 Section 1615.407-1 Federal Acquisition... CONTRACTING METHODS AND CONTRACT TYPES CONTRACTING BY NEGOTIATION Contract Pricing 1615.407-1 Rate reduction for defective pricing or defective cost or pricing data. The clause set forth in section...

  6. Laterality defects in the national birth defects prevention study 1998-2007 birth prevalence and descriptive epidemiology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Little is known epidemiologically about laterality defects. Using data from the National Birth Defects Prevention Study (NBDPS), a large multi-site case-control study of birth defects, we analyzed prevalence and selected characteristics in children born with laterality defects born from 1998 to 2007...

  7. Birth defects in pregestational diabetes: Defect range, glycemic threshold and pathogenesis.

    PubMed

    Gabbay-Benziv, Rinat; Reece, E Albert; Wang, Fang; Yang, Peixin

    2015-04-15

    Currently, 60 million women of reproductive age (18-44 years old) worldwide, and approximately 3 million American women have diabetes mellitus, and it has been estimated that this number will double by 2030. Pregestational diabetes mellitus (PGD) is a significant public health problem that increases the risk for structural birth defects affecting both maternal and neonatal pregnancy outcome. The most common types of human structural birth defects associated with PGD are congenital heart defects and central nervous system defects. However, diabetes can induce birth defects in any other fetal organ. In general, the rate of birth defects increases linearly with the degree of maternal hyperglycemia, which is the major factor that mediates teratogenicity of PGD. Stringent prenatal care and glycemic control are effective means to reduce birth defects in PGD pregnancies, but cannot reduce the incidence of birth defects to the rate of that is seen in the nondiabetic population. Studies in animal models have revealed that PGD induces oxidative stress, which activates cellular stress signalling leading to dysregulation of gene expression and excess apoptosis in the target organs, including the neural tube and embryonic heart. Activation of the apoptosis signal-regulating kinase 1 (ASK1)-forkhead transcription factor 3a (FoxO3a)-caspase 8 pathway causes apoptosis in the developing neural tube leading to neural tube defects (NTDs). ASK1 activates the c-Jun-N-Terminal kinase 1/2 (JNK1/2), which leads to activation of the unfolded protein response and endoplasmic reticulum (ER) stress. Deletion of the ASK1 gene, the JNK1 gene, or the JNK2 gene, or inhibition of ER stress by 4-Phenylbutyric acid abrogates diabetes-induced apoptosis and reduces the formation of NTDs. Antioxidants, such as thioredoxin, which inhibits the ASK1-FoxO3a-caspase 8 pathway or ER stress inhibitors, may prevent PGD-induced birth defects. PMID:25897357

  8. Birth defects in pregestational diabetes: Defect range, glycemic threshold and pathogenesis

    PubMed Central

    Gabbay-Benziv, Rinat; Reece, E Albert; Wang, Fang; Yang, Peixin

    2015-01-01

    Currently, 60 million women of reproductive age (18-44 years old) worldwide, and approximately 3 million American women have diabetes mellitus, and it has been estimated that this number will double by 2030. Pregestational diabetes mellitus (PGD) is a significant public health problem that increases the risk for structural birth defects affecting both maternal and neonatal pregnancy outcome. The most common types of human structural birth defects associated with PGD are congenital heart defects and central nervous system defects. However, diabetes can induce birth defects in any other fetal organ. In general, the rate of birth defects increases linearly with the degree of maternal hyperglycemia, which is the major factor that mediates teratogenicity of PGD. Stringent prenatal care and glycemic control are effective means to reduce birth defects in PGD pregnancies, but cannot reduce the incidence of birth defects to the rate of that is seen in the nondiabetic population. Studies in animal models have revealed that PGD induces oxidative stress, which activates cellular stress signalling leading to dysregulation of gene expression and excess apoptosis in the target organs, including the neural tube and embryonic heart. Activation of the apoptosis signal-regulating kinase 1 (ASK1)-forkhead transcription factor 3a (FoxO3a)-caspase 8 pathway causes apoptosis in the developing neural tube leading to neural tube defects (NTDs). ASK1 activates the c-Jun-N-Terminal kinase 1/2 (JNK1/2), which leads to activation of the unfolded protein response and endoplasmic reticulum (ER) stress. Deletion of the ASK1 gene, the JNK1 gene, or the JNK2 gene, or inhibition of ER stress by 4-Phenylbutyric acid abrogates diabetes-induced apoptosis and reduces the formation of NTDs. Antioxidants, such as thioredoxin, which inhibits the ASK1-FoxO3a-caspase 8 pathway or ER stress inhibitors, may prevent PGD-induced birth defects. PMID:25897357

  9. A Defect Reduction Methodology For Increased Sort Yield Using Automated Defect Inspection

    NASA Astrophysics Data System (ADS)

    Radin, Christopher

    1988-01-01

    This paper addresses the task of finding the source of defects that cause die failure at sort on semiconductor wafers. To do this, one must be able to determine defect type and density, in process, in order to determine where in the manufacturing process they are being created. Two methods have been commonly used. First is operator performed inspection of product or test wafers using a microscope. The second is short loop experiments using electrical test structures. Each of these methods have significant limitations when used for engineering analysis on VLSI technologies. Data generated by operator performed inspections show lack of reproducibility and large variations from operator to operator. Also, operator sensitivity declines to very low levels for defect sizes approaching linewidths in current semiconductor technologies. Electrical test structures require a conductive thin film to be patterned and etched. To get finer resolution of the section of the process causing a defect, indirect methods are required. This greatly constrains the options for experimental procedures. Because of the limitations on the methods described so far, defect reduction projects have been difficult, time consuming and prone to failure due to the difficulty of identifying the source of defects. Automated defect inspection, using the KLA-2020 automated wafer inspector, addresses these problems. This results in greatly increased efficiency and success rate. Presented in this paper is a discussion of the capabilities of automated defect inspection as compared to operator performed inspections and electrical test structure based short loop experiments. Also, a defect reduction methodology utilizing automated inspection will be described by presenting an actual example of its application. The methodology consists of using standard problem solving and experiment design techniques to isolate and solve major defect mechanisms. The example presented describes a series of short loop

  10. Three dimensional echocardiography in congenital heart defects

    PubMed Central

    Shirali, Girish S.

    2008-01-01

    Three dimensional echocardiography (3DE) is a new, rapidly evolving modality for cardiac imaging. Important technological advances have heralded an era where practical 3DE scanning is becoming a mainstream modality. We review the modes of 3DE that can be used. The literature has been reviewed for articles that examine the applicability of 3DE to congenital heart defects to visualize anatomy in a spectrum of defects ranging from atrioventricular septal defects to mitral valve abnormalities and Ebstein's anomaly. The use of 3DE color flow to obtain echocardiographic angiograms is illustrated. The state of the science in quantitating right and left ventricular volumetrics is reviewed. Examples of novel applications including 3DE transesophageal echocardiography and image-guided interventions are provided. We also list the limitations of the technique, and discuss potential future developments in the field. PMID:20300232

  11. Ribosome defects in disorders of erythropoiesis.

    PubMed

    Narla, Anupama; Hurst, Slater N; Ebert, Benjamin L

    2011-02-01

    Over the past decade, genetic lesions that cause ribosome dysfunction have been identified in both congenital and acquired human disorders. These discoveries have established a new category of disorders, known as ribosomopathies, in which the primary pathophysiology is related to impaired ribosome function. The protoptypical disorders are Diamond-Blackfan anemia, a congenital bone marrow failure syndrome, and the 5q- syndrome, a subtype of myelodysplastic syndrome. In both of these disorders, impaired ribosome function causes a severe macrocytic anemia. In this review, we will discuss the evidence that defects in ribosomal biogenesis cause the hematologic phenotype of Diamond-Blackfan anemia and the 5q- syndrome. We will also explore the potential mechanisms by which a ribosomal defect, which would be expected to have widespread consequences, may lead to specific defects in erythropoiesis. PMID:21279816

  12. Osteochondral defects in the ankle: why painful?

    PubMed Central

    Reilingh, Mikel L.; Zengerink, Maartje; van Bergen, Christiaan J. A.

    2010-01-01

    Osteochondral defects of the ankle can either heal and remain asymptomatic or progress to deep ankle pain on weight bearing and formation of subchondral bone cysts. The development of a symptomatic OD depends on various factors, including the damage and insufficient repair of the subchondral bone plate. The ankle joint has a high congruency. During loading, compressed cartilage forces its water into the microfractured subchondral bone, leading to a localized high increased flow and pressure of fluid in the subchondral bone. This will result in local osteolysis and can explain the slow development of a subchondral cyst. The pain does not arise from the cartilage lesion, but is most probably caused by repetitive high fluid pressure during walking, which results in stimulation of the highly innervated subchondral bone underneath the cartilage defect. Understanding the natural history of osteochondral defects could lead to the development of strategies for preventing progressive joint damage. PMID:20151110

  13. Defects and degeneracies in supersymmetry protected phases

    NASA Astrophysics Data System (ADS)

    Fokkema, Thessa; Schoutens, Kareljan

    2015-08-01

    We analyse a class of 1D lattice models, known as \\text{M}k models, which are characterised by an order-k clustering of spin-less fermions and by N}=2 lattice supersymmetry. Our main result is the identification of a class of (bulk or edge) defects, that are in one-to-one correspondence with so-called spin fields in a corresponding {Z}k parafermion CFT. In the gapped regime, injecting such defects leads to ground-state degeneracies that are protected by the supersymmetry. The defects, which are closely analogous to quasi-holes over the fermonic Read-Rezayi quantum Hall states, display characteristic fusion rules, which are of Ising type for k = 2 and of Fibonacci type for k = 3.

  14. Structural control design and defective systems

    NASA Astrophysics Data System (ADS)

    Gattulli, Vincenzo; Potenza, Francesco

    2016-05-01

    The intersection between the two concepts of structural control and defectiveness is discussed. Two simple oscillators differently connected by serial spring-dashpot arrangement are used to simply simulate technically relevant cases: dissipatively coupled adjacent free-standing structures, structures equipped by TMD and base-isolated structures. Eigensolution loci of the two classes of systems are tracked against one or more significant parameters to determine the potential benefits realized by different combinations of stiffness and viscosity. In both studied cases, codimension-two manifolds in the four-parameter space corresponding to coalescing eigenvalues are determined by analytical expressions. Conditions to discern semi-simple eigenvalues from defective ones confirm that the latter is the generic case laying in a two-parameter space while the former span a one-parameter subspace. The knowledge of the location of the defective systems in the parameter space permits to determine regions with specific dynamical properties useful for control design purpose.

  15. Quantitative defect characterization via guided waves

    NASA Astrophysics Data System (ADS)

    Zhao, Xiaoliang

    Pipeline inspection systems are being developed to locate critical defects, and more recently to characterize and size them efficiently in order to prevent potential leakage or catastrophic failure, as well as to assist in the decision process of wait or replace. Ultrasonic guided waves have demonstrated their abilities and advantages of detecting a variety of defect types that occur in a plate or hollow cylindrical structure compared to other conventional methods. Yet defect classification and sizing in these structures by guided waves is still a major issue. In this work, the Boundary Element Method (BEM) combined with the guided wave normal mode expansion technique is used to study the interaction of various guided wave packets of energy with various crack and corrosion boundaries in a structure. Attempts are made to find the best modes and frequency with the best chance of success in carrying out the defect classification and sizing process. To simplify the problem, a plate model is used to approximate the wall structure of a hollow cylinder of large diameter-to-wall-thickness ratio. The dispersion relation and wave structures of Shear Horizontal (SH) waves along the circumference of a hollow cylinder is derived and calculated. A parametric study with the hollow cylinder wall thickness to diameter ratio is conducted. Together with similar studies on circumferential Lamb waves in a pipe wall, a quantitative criterion as when a hollow cylinder wall can indeed be treated as a plate is given. A two-dimensional boundary element method (BEM) FORTRAN code was developed for surface breaking defect characterization and sizing in a plate using guided waves. A new code is developed for internal inclusion types of defect that are considered benign to see whether they will give false alarms. Parametric studies on different incident wave modes and frequencies establish a guideline on how to characterize a defect in a two-dimensional wave guide. In reality, all defects are

  16. Ultrastructure of internal jugular vein defective valves

    PubMed Central

    Tisato, V; Menegatti, E; Mascoli, F; Gianesini, S; Salvi, F; Secchiero, P

    2015-01-01

    Objectives To study the ultrastructure of intraluminal defects found in the internal jugular vein by using a scanning electron microscopy. Methods Using a scanning electron microscopy, intraluminal septa and/or defective valves blocking the flow in the distal internal jugular vein of seven patients were studied together with the adjacent wall and compared with control specimen. Results The internal jugular veins’ wall showed a significant derangement of the endothelial layer as compared to controls. Surprisingly, no endothelial cells were found in the defective cusps, and the surface of the structure is covered by a fibro-reticular lamina. Conclusions Although the lack of endothelial cells in the internal jugular vein intraluminal obstacles is a further abnormality found in course of chronic cerebrospinal venous insufficiency, our investigation cannot clarify whether this finding is primary or caused by progressive loss of endothelium in relation to altered haemodynamic forces and/or to a past post-thrombotic/inflammatory remodelling. PMID:24972760

  17. Genetic defects in ciliary structure and function.

    PubMed

    Zariwala, Maimoona A; Knowles, Michael R; Omran, Heymut

    2007-01-01

    Cilia, hair-like structures extending from the cell membrane, perform diverse biological functions. Primary (genetic) defects in the structure and function of sensory and motile cilia result in multiple ciliopathies. The most prominent genetic abnormality involving motile cilia (and the respiratory tract) is primary ciliary dyskinesia (PCD). PCD is a rare, usually autosomal recessive, genetically heterogeneous disorder characterized by sino-pulmonary disease, laterality defects, and male infertility. Ciliary ultrastructural defects are identified in approximately 90% of PCD patients and involve the outer dynein arms, inner dynein arms, or both. Diagnosing PCD is challenging and requires a compatible clinical phenotype together with tests such as ciliary ultrastructural analysis, immunofluorescent staining, ciliary beat assessment, and/or nasal nitric oxide measurements. Recent mutational analysis demonstrated that 38% of PCD patients carry mutations of the dynein genes DNAI1 and DNAH5. Increased understanding of the pathogenesis will aid in better diagnosis and treatment of PCD. PMID:17059358

  18. Flap Coverage of Anterior Abdominal Wall Defects

    PubMed Central

    Sacks, Justin M.; Broyles, Justin M.; Baumann, Donald P.

    2012-01-01

    Reconstruction of complex defects of the anterior abdomen is both challenging and technically demanding for reconstructive surgeons. Advancements in the use of pedicle and free tissue transfer along with the use of bioprosthetic and synthetic meshes have provided for novel approaches to these complex defects. Accordingly, detailed knowledge of abdominal wall and lower extremity anatomy in combination with insight into the design, implementation, and limitations of various flaps is essential to solve these complex clinical problems. Although these defects can be attributed to a myriad of etiologic factors, the objectives in abdominal wall reconstruction are consistent and include the restoration of abdominal wall integrity, protection of intraabdominal viscera, and the prevention of herniation. In this article, the authors review pertinent anatomy and the various local, regional, and distant flaps that can be utilized in the reconstruction of these complex clinical cases of the anterior abdomen. PMID:23372457

  19. Defect Detection Using Hidden Markov Random Fields

    NASA Astrophysics Data System (ADS)

    Dogandžić, Aleksandar; Eua-anant, Nawanat; Zhang, Benhong

    2005-04-01

    We derive an approximate maximum a posteriori (MAP) method for detecting NDE defect signals using hidden Markov random fields (HMRFs). In the proposed HMRF framework, a set of spatially distributed NDE measurements is assumed to form a noisy realization of an underlying random field that has a simple structure with Markovian dependence. Here, the random field describes the defect signals to be estimated or detected. The HMRF models incorporate measurement locations into the statistical analysis, which is important in scenarios where the same defect affects measurements at multiple locations. We also discuss initialization of the proposed HMRF detector and apply to simulated eddy-current data and experimental ultrasonic C-scan data from an inspection of a cylindrical Ti 6-4 billet.

  20. Preliminary work on the quantum defect measurements

    NASA Astrophysics Data System (ADS)

    Hutcherson, Lindsay; Sanders, Justin; Han, Jianing

    2016-05-01

    Van der Waals interactions are generally studied in physics, chemistry, biology, and other fields of science. In order to fine-tune van der Waals interactions, the atomic energy levels need to be known very accurately. That is, we must accurately determine the quantum defects. Quantum defects of 85Rb have been recently measured, and the quantum defects of 87Rb have also been measured for nS and nD states with the resolution of 1 MHz. this experiment will focus on the P, F, and G states, which are higher angular momentum states and more sensitive to electric fields. These states are crucial for collisions, which may lead to some of the interesting phenomena in ultracold atoms, such as ultracold plasma. In this presentation, a progress report will be given on this project. The authors would like to acknowledge the travel Grants from DDOE and the University of South Alabama.

  1. Global defect topology in nematic liquid crystals

    PubMed Central

    Machon, Thomas

    2016-01-01

    We give the global homotopy classification of nematic textures for a general domain with weak anchoring boundary conditions and arbitrary defect set in terms of twisted cohomology, and give an explicit computation for the case of knotted and linked defects in R3, showing that the distinct homotopy classes have a 1–1 correspondence with the first homology group of the branched double cover, branched over the disclination loops. We show further that the subset of those classes corresponding to elements of order 2 in this group has representatives that are planar and characterize the obstruction for other classes in terms of merons. The planar textures are a feature of the global defect topology that is not reflected in any local characterization. Finally, we describe how the global classification relates to recent experiments on nematic droplets and how elements of order 4 relate to the presence of τ lines in cholesterics. PMID:27493576

  2. Defect unbinding on a toroidal nematic shell.

    PubMed

    Jesenek, Dalija; Kralj, Samo; Rosso, Riccardo; Virga, Epifanio G

    2015-03-28

    We study nematic liquid crystal textures exhibiting topological defects (TDs) on a two-dimensional (2D) toroidal shell. For the toroidal topology the total topological charge of TDs is equal to zero. We use a mesoscopic Landau-de Gennes approach which features a 2D nematic order tensor Q. We show that fat tori unbind TDs. If no extrinsic free energy couples Q with the Weingarten tensor of the torus, then defects and antidefects are assembled along the innermost and the outermost circles of the torus, respectively. In this case, we estimate the critical condition for the onset of TDs using an electrostatic analogy. If, on the other hand, an extrinsic free energy is present, then defects are repelled from these regions. PMID:25662487

  3. Air pollution and congenital heart defects.

    PubMed

    Agay-Shay, Keren; Friger, Michael; Linn, Shai; Peled, Ammatzia; Amitai, Yona; Peretz, Chava

    2013-07-01

    Environmental factors such as ambient air pollution have been associated with congenital heart defects. The aim of this study was to investigate the association between gestational exposure to air pollution and the risk of congenital heart defects. We conducted a registry-based cohort study with a total of 135,527 live- and still-births in the Tel-Aviv region during 2000-2006. We used a Geographic Information System-based spatiotemporal approach with weekly inverse distance weighting modeling to evaluate associations between gestational exposure to ambient air pollution during weeks 3-8 of pregnancy and the risk for congenital heart defects. The following pollutants were studied: carbon monoxide, nitrogen-dioxide, ozone, sulfur-dioxide and particulate matter with aerodynamic diameter smaller than 10 μm and 2.5 μm (PM10, PM2.5 respectively). Logistic models, adjusted for socio-demographic covariates were used to evaluate the associations. We found that maternal exposure to increased concentrations of PM10 was associated with multiple congenital heart defects (adjusted OR 1.05, 95% CI: 1.01 to 1.10 for 10 μg/m(3) increment). An inverse association was observed between concentrations of PM2.5 and isolated patent ductus arteriosus (adjusted OR 0.78, 95% CI: 0.68 to 0.91 for 5 µg/m(3) increment). Sensitivity analyses showed that results were consistent. Generally there were no evidence for an association between gaseous air pollutants and congenital heart defects.Our results for PM10 and congenital heart defects confirm results from previous studies. The results for PM2.5 need further investigations. PMID:23623715

  4. Reduction in Defect Content of ODS Alloys

    SciTech Connect

    Ritherdon, J

    2003-11-17

    The work detailed within this report is a continuation of earlier work carried out under contract number 1DX-SY382V. The earlier work comprises a literature review of the sources and types of defects found principally in Fe-based ODS alloys as well as experimental work designed to identify defects in the prototype ODS-Fe{sub 3}Al alloy, deduce their origins and to recommend methods of defect reduction. The present work is an extension of the experimental work already reported and concentrates on means of reduction of defects already identified rather than the search for new defect types. This report also includes work regarding the manipulation of grain structures via deformation processing and further results gathered during powder separation trials involving the separation of different metallic powders in terms of their differing densities. The scope and objectives of the present work were laid out in the technical proposal ''Reduction in Defect Content in ODS Alloys-IV''. All the work proposed in the ''Statement of Work'' section of the technical proposal has been carried out except for some of that dependent on the acquisition of materials from other sources. However, wherever omissions from the ''Plan of Action'' detailed in the ''Statement of Work'' have occurred due to lack of suitable materials, other related experimental work has been devised to fill the gaps where possible. All work extra to the ''Statement of Work'' falls within the context of an ODS-Fe{sub 3}Al alloy of improved overall quality and potential creep performance in the consolidated form. The outturn of the experimental work performed is reported in the following sections.

  5. Toward defect guard-banding of EUV exposures by full chip optical wafer inspection of EUV mask defect adders

    NASA Astrophysics Data System (ADS)

    Halle, Scott D.; Meli, Luciana; Delancey, Robert; Vemareddy, Kaushik; Crispo, Gary; Bonam, Ravi; Burkhardt, Martin; Corliss, Daniel

    2015-03-01

    The detection of EUV mask adder defects has been investigated with an optical wafer defect inspection system employing a methodology termed Die-to-"golden" Virtual Reference Die (D2VRD). Both opaque and clear type mask absorber programmed defects were inspected and characterized over a range of defect sizes, down to (4x mask) 40 nm. The D2VRD inspection system was capable of identifying the corresponding wafer print defects down to the limit of the defect printability threshold at approximately 30 nm (1x wafer). The efficacy of the D2VRD scheme on full chip wafer inspection to suppress random process defects and identify real mask defects is demonstrated. Using defect repeater analysis and patch image classification of both the reference die and the scanned die enables the unambiguous identification of mask adder defects.

  6. Dirac oscillator interacting with a topological defect

    SciTech Connect

    Carvalho, J.; Furtado, C.; Moraes, F.

    2011-09-15

    In this work we study the interaction problem of a Dirac oscillator with gravitational fields produced by topological defects. The energy levels of the relativistic oscillator in the cosmic string and in the cosmic dislocation space-times are sensible to curvature and torsion associated to these defects and are important evidence of the influence of the topology on this system. In the presence of a localized magnetic field the energy levels acquire a term associated with the Aharonov-Bohm effect. We obtain the eigenfunctions and eigenvalues and see that in the nonrelativistic limit some results known in standard quantum mechanics are reached.

  7. Haemostatic defects in cyanotic congenital heart disease.

    PubMed Central

    Henriksson, P; Värendh, G; Lundström, N R

    1979-01-01

    An investigation of defects of the haemostatic mechanism in 41 children with cyanotic congenital heart disease concluded that such abnormalities were common and normally involved factors synthesised in the liver, that is the vitamin K dependent factors (rothrombin, factors VII and IX) and factor V. No evidence was found of activation of the coagulation or fibrinolytic systems. The defects can be explained by deficient synthesis resulting from systemic hypoxia as well as from sluggishness of the local microcirculation caused by high blood viscosity. Vitamin K parenterally had no demonstrable effect. Replacement of these factors, possibly combined with measures to improve the microcirculation, therefore, appears to be the appropriate treatment. PMID:426953

  8. GaN: Defect and Device Issues

    SciTech Connect

    Pearton, S.J.; Ren, F.; Shul, R.J.; Zolper, J.C.

    1998-11-09

    The role of extended and point defects, and key impurities such as C, O and H, on the electrical and optical properties of GaN is reviewed. Recent progress in the development of high reliability contacts, thermal processing, dry and wet etching techniques, implantation doping and isolation and gate insulator technology is detailed. Finally, the performance of GaN-based electronic and photonic devices such as field effect transistors, UV detectors, laser diodes and light-emitting diodes is covered, along with the influence of process-induced or grown-in defects and impurities on the device physics.

  9. Agglomeration defects on irradiated carbon nanotubes

    SciTech Connect

    Steini Moura, Cassio; Balzaretti, Naira Maria; Amaral, Livio; Gribel Lacerda, Rodrigo; Pimenta, Marcos A.

    2012-03-15

    Aligned carbon nanotubes (CNT) were irradiated in the longitudinal and perpendicular directions, with low energy carbon and helium ions in order to observe the formation of defects in the atomic structure. Analysis through Raman spectroscopy and scanning electron microscopy indicated bundle rupture and ion track formation on nanotube bundles. Aligned CNT presented a kind of defect comprising ravine formation and tube agglomeration on top of the substrate. The latter structure is possibly caused by static charge accumulation induced by the incoming ions. Fluence plays a role on the short range order. Higher fluence irradiation transforms CNT into amorphous carbon nanowires.

  10. Holographic dual of a conical defect

    NASA Astrophysics Data System (ADS)

    Arefeva, I. Ya.; Bagrov, A. A.

    2015-01-01

    We consider a moving conical defect in the pure AdS3 space-time and calculate two-point correlation functions of a corresponding two-dimensional boundary quantum field theory in the geodesic approximation. We show that the presence of the defect leads to a gravitational lensing of geodesics, and this results in a finite number of similar terms in the Green's function that correspond to winding geodesics in the bulk around the conical singularity. We show that for the quantized deficit angle γ = π/2n, the lensing produces domain wall excitations in the spectrum of the boundary theory.

  11. Defect dynamics in crystalline buckled membranes

    NASA Astrophysics Data System (ADS)

    Pezzutti, Aldo D.; Vega, Daniel A.

    2011-07-01

    We study the dynamics of defect annihilation in flexible crystalline membranes suffering a symmetry-breaking phase transition. The kinetic process leading the system toward equilibrium is described through a Brazovskii-Helfrich-Canham Hamiltonian. In membranes, a negative disclination has a larger energy than a positive disclination. Here we show that this energetic asymmetry does not only affect equilibrium properties, like the Kosterlitz-Thouless transition temperature, but also plays a fundamental role in the dynamic of defects. Both unbinding of dislocations and Carraro-Nelson “antiferromagnetic” interactions between disclinations slow down the dynamics below the Lifshitz-Safran regime observed in flat hexagonal systems.

  12. Construction of Radial Defect Models in Rabbits to Determine the Critical Size Defects

    PubMed Central

    Zhang, Xin-Chao; Gui, Ke-Ke; Xiong, Min; Yin, Wang-Ping; Yuan, Feng-Lai; Cai, Guo-Ping

    2016-01-01

    Many studies aimed at investigating bone repair have been conducted through animal models in recent years. However, limitations do exist in these models due to varying regeneration potential among different animal species. Even using the same animal, big differences exist in the size of critical size defects (CSD) involving the same region. This study aimed to investigate the standardization of radial bone defect models in rabbits and further establish more reliable CSD data. A total of 40 6-month-old New Zealand white rabbits of clean grade totaling 80 radial bones were prepared for bone defect models, according to the principle of randomization. Five different sizes (1.0, 1.2, 1.4, 1.7 and 2.0 cm) of complete periosteal defects were introduced under anesthesia. At 12 weeks postoperatively, with the gradual increase in defect size, the grades of bone growth were significantly decreased in all 5 groups. X-ray, CT scans and H&E staining of the 1.4, 1.7, and 2.0-cm groups showed lower grades of bone growth than that of the 1.0 and 1.2-cm groups respectively (P < 0.05). Using rabbit radial defect model involving 6-month-old healthy New Zealand white rabbits, this study indicates that in order to be critical sized, defects must be greater than 1.4 cm. PMID:26731011

  13. Accurate defect die placement and nuisance defect reduction for reticle die-to-die inspections

    NASA Astrophysics Data System (ADS)

    Wen, Vincent; Huang, L. R.; Lin, C. J.; Tseng, Y. N.; Huang, W. H.; Tuo, Laurent C.; Wylie, Mark; Chen, Ellison; Wang, Elvik; Glasser, Joshua; Kelkar, Amrish; Wu, David

    2015-10-01

    Die-to-die reticle inspections are among the simplest and most sensitive reticle inspections because of the use of an identical-design neighboring-die for the reference image. However, this inspection mode can have two key disadvantages: (1) The location of the defect is indeterminate because it is unclear to the inspector whether the test or reference image is defective; and (2) nuisance and false defects from mask manufacturing noise and tool optical variation can limit the usable sensitivity. The use of a new sequencing approach for a die-to-die inspection can resolve these issues without any additional scan time, without sacrifice in sensitivity requirement, and with a manageable increase in computation load. In this paper we explore another approach for die-to-die inspections using a new method of defect processing and sequencing. Utilizing die-to-die double arbitration during defect detection has been proven through extensive testing to generate accurate placement of the defect in the correct die to ensure efficient defect disposition at the AIMS step. The use of this method maintained the required inspection sensitivity for mask quality as verified with programmed-defectmask qualification and then further validated with production masks comparing the current inspection approach to the new method. Furthermore, this approach can significantly reduce the total number of defects that need to be reviewed by essentially eliminating the nuisance and false defects that can result from a die-to-die inspection. This "double-win" will significantly reduce the effort in classifying a die-to-die inspection result and will lead to improved cycle times.

  14. Defect production and recombination during low-energy ion processing

    SciTech Connect

    Kellerman, B.K.; Floro, J.A.; Chason, E.; Brice, D.K.; Picraux, S.T.; White, J.M.

    1994-10-01

    Low-energy ion processing produces damaged, microroughened semiconductor surfaces due to the production of point defects. The authors present a study of point defect production and annealing on the Ge(001)-2x1 surface during low-energy inert ion bombardment as a function of ion energy, ion mass and substrate temperature. Ion-induced surface point defect production was quantified experimentally in real time using in situ Reflection High Energy Electron Diffraction. The observed surface defect yield decreased abruptly around room temperature as the substrate temperature was increased from 175 K to 475 K. The authors have developed Monte Carlo simulations of defect diffusion to model defect recombination both in the bulk and on the surface. Bulk defect production statistics generated by a binary collision simulator, TRIMRC, were coupled with our bulk diffusion simulator to predict the number of ion-induced surface defects. A comparison between the experimental results and the simulation predictions indicated that defects produced in the bulk may represent a significant contribution to the observed surface defect yield and suggested that TRIMRC may overestimate the depth distribution of the defects. The simulations further indicated that the abrupt drop in the experimental yield with increasing substrate temperature does not arise from bulk defect recombination. The Monte Carlo simulations of surface diffusion (applicable to any crystalline surface) support a defect annealing mechanism (at low ion fluxes) that involves surface recombination of defects generated within a single cascade.

  15. Defect mode properties of two-dimensional plasma-filled defective metallic photonic crystal

    SciTech Connect

    Fu, T.; Yang, Z.; Tang, X.; Shi, Z.; Lan, F.

    2014-01-15

    This paper studies the frequency and amplitude properties of a defect mode which is only in a plasma-filled metallic photonic crystal with defect layer. Results show that the frequency almost has no change and the amplitude declines gradually with the growth of the number of the layers. The frequency of the defect mode not only can be modulated by filling ratio but also can be tuned by plasma density without modifying the structure. The amplitude can be modified by plasma angular frequency as well. These characteristics provide a foundation to design tunable filters, high power millimeter devices.

  16. Tegmental defects and cerebrospinal fluid otorrhea.

    PubMed

    Valtonen, H; Geyer, C; Tarlov, E; Heilman, C; Poe, D

    2001-01-01

    Congenital tegmental defects that present as unsuspected cerebrospinal fluid (CSF) otorrhea are diagnostic and therapeutic challenges. We reviewed 5 such patients to determine an optimal strategy for evaluation. Five patients presented with watery otorrhea, 4 of them after ventilation tube placement, and only 1 with rhinorrhea. The preoperative analysis of middle ear effusion for beta(2)-transferrin was positive in 2/4, equivocal in 1/4 and false negative in 1/4. Computerized tomography (CT) revealed nonspecific tegmental defects in all 5 patients. Magnetic resonance imaging (MRI) demonstrated meningoencephalocele in 3/5 and dural irregularity in 1/5. Tegmental defects were confirmed at surgery in all cases, demonstrating meningocele or arachnoid granulations in 2/5 and encephalocele in 2/5 patients. We recommend a combination of beta(2)-transferrin analysis to verify CSF, high resolution CT (axial and coronal planes) to diagnose tegmental defects, and MRI (multiplanar) to evaluate the type of herniation. A combination mastoid and middle fossa approach for definitive repair is suggested. PMID:11174062

  17. 9 CFR 91.30 - Defective fittings.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Defective fittings. 91.30 Section 91.30 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE... used fittings aboard an ocean vessel are employed, any portion thereof found by the inspector to...

  18. Fuzzy Logic Connectivity in Semiconductor Defect Clustering

    SciTech Connect

    Gleason, S.S.; Kamowski, T.P.; Tobin, K.W.

    1999-01-24

    In joining defects on semiconductor wafer maps into clusters, it is common for defects caused by different sources to overlap. Simple morphological image processing tends to either join too many unrelated defects together or not enough together. Expert semiconductor fabrication engineers have demonstrated that they can easily group clusters of defects from a common manufacturing problem source into a single signature. Capturing this thought process is ideally suited for fuzzy logic. A system of rules was developed to join disconnected clusters based on properties such as elongation, orientation, and distance. The clusters are evaluated on a pair-wise basis using the fuzzy rules and are joined or not joined based on a defuzzification and threshold. The system continuously re-evaluates the clusters under consideration as their fuzzy memberships change with each joining action. The fuzzy membership functions for each pair-wise feature, the techniques used to measure the features, and methods for improving the speed of the system are all developed. Examples of the process are shown using real-world semiconductor wafer maps obtained from chip manufacturers. The algorithm is utilized in the Spatial Signature Analyzer (SSA) software, a joint development project between Oak Ridge National Lab (ORNL) and SEMATECH.

  19. Alcohol Related Birth Defects: Implications for Education.

    ERIC Educational Resources Information Center

    Lamanna, Michael

    1982-01-01

    Discusses background and nature of alcohol-related birth defects. Describes a continuum of impairment to offspring of drinking mothers that is dose-related and produces serious behavioral/learning deficits. The continuum includes young people of normal intelligence who perform below expected levels and find school adjustment difficult. Offers…

  20. [Placental developmental defects in cloned mammalian animals].

    PubMed

    Ao, Zheng; Liu, Dewu; Cai, Gengyuan; Wu, Zhenfang; Li, Zicong

    2016-05-01

    The cloning technique, also called somatic cell nuclear transfer (SCNT), has been successfully established and gradually applied to various mammalian species. However, the developmental rate of SCNT mammalian embryos is very low, usually at 1% to 5%, which limits the application of SCNT. Placental developmental defects are considered as the main cause of SCNT embryo development inhibition. Almost all of SCNT-derived mammalian placentas exhibit various abnormalities, such as placental hyperplasia, vascular defects and umbilical cord malformation. Mechanistically, these abnormalities result from failure of establishment of correct epigenetic modification in the trophectoderm genome, which leads to erroneous expression of important genes for placenta development-related, particularly imprinted genes. Consequently, aberrant imprinted gene expression gives rise to placental morphologic abnormalities and functional defects, therefore decreases developmental competence of cloned embryos. Currently, although numerous methods that can improve the developmental ability of SCNT-derived embryos have been reported, most of them are unable to substantially enhance the success rate of SCNT due to failure to eliminate the placental development defects. In this review, we summarize placental abnormalities and imprinted gene expression in mammalian cloning, and propose directions for the future research aiming to improve the cloning efficiency. PMID:27232488

  1. Volterra distortions, spinning strings, and cosmic defects

    NASA Astrophysics Data System (ADS)

    Puntigam, Roland A.; Soleng, Harald H.

    1997-05-01

    Cosmic strings, as topological spacetime defects, show striking resemblance to defects in solid continua: distortions, which can be classified into disclinations and dislocations, are line-like defects characterized by a delta-function-valued curvature and torsion distribution giving rise to rotational and translational holonomy. We exploit this analogy and investigate how distortions can be adapted in a systematic manner from solid-state systems to Einstein - Cartan gravity. As distortions are efficiently described within the framework of an 0264-9381/14/5/017/img5 gauge theory of solid continua with line defects, we are led in a straightforward way to a Poincaré gauge approach to gravity which is a natural framework for introducing the notion of distorted spacetimes. Constructing all ten possible distorted spacetimes, we recover, inter alia, the well known exterior spacetime of a spin-polarized cosmic string as a special case of such a geometry. In a second step, we search for matter distributions which, in Einstein - Cartan gravity, act as sources of distorted spacetimes. The resulting solutions, appropriately matched to the distorted vacua, are cylindrically symmetric and are interpreted as spin-polarized cosmic strings and cosmic dislocations.

  2. Oil defect detection of electrowetting display

    NASA Astrophysics Data System (ADS)

    Chiang, Hou-Chi; Tsai, Yu-Hsiang; Yan, Yung-Jhe; Huang, Ting-Wei; Mang, Ou-Yang

    2015-08-01

    In recent years, transparent display is an emerging topic in display technologies. Apply in many fields just like mobile device, shopping or advertising window, and etc. Electrowetting Display (EWD) is one kind of potential transparent display technology advantages of high transmittance, fast response time, high contrast and rich color with pigment based oil system. In mass production process of Electrowetting Display, oil defects should be found by Automated Optical Inspection (AOI) detection system. It is useful in determination of panel defects for quality control. According to the research of our group, we proposed a mechanism of AOI detection system detecting the different kinds of oil defects. This mechanism can detect different kinds of oil defect caused by oil overflow or material deteriorated after oil coating or driving. We had experiment our mechanism with a 6-inch Electrowetting Display panel from ITRI, using an Epson V750 scanner with 1200 dpi resolution. Two AOI algorithms were developed, which were high speed method and high precision method. In high precision method, oil jumping or non-recovered can be detected successfully. This mechanism of AOI detection system can be used to evaluate the oil uniformity in EWD panel process. In the future, our AOI detection system can be used in quality control of panel manufacturing for mass production.

  3. Optical system defect propagation in ABCD systems.

    PubMed

    McKinley, W G; Yura, H T; Hanson, S G

    1988-05-01

    We describe how optical system defects (tilt/jitter, decenter, and despace) propagate through an arbitrary paraxial optical system that can be described by an ABCD ray transfer matrix. A pedagogical example is given that demonstrates the effect of alignment errors on a typical optical system. PMID:19745889

  4. Defect accommodation in nanostructured soft crystals.

    PubMed

    Exner, Alexander; Rosenfeldt, Sabine; Fischer, Steffen; Lindner, Peter; Förster, Stephan

    2014-01-01

    A detailed analysis of the structure of lyotropic micellar FCC soft crystals was performed by scanning small-angle neutron scattering. Soft crystals have a large number of structural defects, leading to characteristic features in the scattering patterns such as secondary Bragg peaks, diffuse scattering lines, and paracrystalline distortions. We find that the presence of a large number of defects locally breaks the three-dimensional symmetry of the crystal, leading to weakly correlated assemblies of stacked {111} layers. Positional correlations of micelles in different layers are very short ranged, with correlation lengths corresponding to only a few layers. Within the layers, in-plane positional correlations are somewhat longer ranged, but still corresponding to only a few unit cells. Depending on the polydispersity, soft crystals accommodate defects to form mesocrystals of iso-oriented mosaic domains, or paracrystals. The soft layer structures already show characteristic features of two-dimensional systems, exhibiting short-range positional order and longer-ranged orientational order, with similarities to hexatic and recently observed soft quasicrystalline structures. The study shows that defects can be differently accommodated in soft crystals, thereby strongly affecting local and macroscopic positional and orientational order. PMID:24336833

  5. Biomimetic approaches to complex craniofacial defects.

    PubMed

    Teven, Chad M; Fisher, Sean; Ameer, Guillermo A; He, Tong-Chuan; Reid, Russell R

    2015-01-01

    The primary goals of craniofacial reconstruction include the restoration of the form, function, and facial esthetics, and in the case of pediatric patients, respect for craniofacial growth. The surgeon, however, faces several challenges when attempting a reconstructive cranioplasty. For that reason, craniofacial defect repair often requires sophisticated treatment strategies and multidisciplinary input. In the ideal situation, autologous tissue similar in structure and function to that which is missing can be utilized for repair. In the context of the craniofacial skeleton, autologous cranial bone, or secondarily rib, iliac crest, or scapular bone, is most favorable. Often, this option is limited by the finite supply of available bone. Therefore, alternative strategies to repair craniofacial defects are necessary. In the field of regenerative medicine, tissue engineering has emerged as a promising concept, and several methods of bone engineering are currently under investigation. A growth factor-based approach utilizing bone morphogenetic proteins (BMPs) has demonstrated stimulatory effects on cranial bone and defect repair. When combined with cell-based and matrix-based models, regenerative goals can be optimized. This manuscript intends to review recent investigations of tissue engineering models used for the repair of craniofacial defects with a focus on the role of BMPs, scaffold materials, and novel cell lines. When sufficient autologous bone is not available, safe and effective strategies to engineer bone would allow the surgeon to meet the reconstructive goals of the craniofacial skeleton. PMID:26389027

  6. Biomimetic approaches to complex craniofacial defects

    PubMed Central

    Teven, Chad M.; Fisher, Sean; Ameer, Guillermo A.; He, Tong-Chuan; Reid, Russell R.

    2015-01-01

    The primary goals of craniofacial reconstruction include the restoration of the form, function, and facial esthetics, and in the case of pediatric patients, respect for craniofacial growth. The surgeon, however, faces several challenges when attempting a reconstructive cranioplasty. For that reason, craniofacial defect repair often requires sophisticated treatment strategies and multidisciplinary input. In the ideal situation, autologous tissue similar in structure and function to that which is missing can be utilized for repair. In the context of the craniofacial skeleton, autologous cranial bone, or secondarily rib, iliac crest, or scapular bone, is most favorable. Often, this option is limited by the finite supply of available bone. Therefore, alternative strategies to repair craniofacial defects are necessary. In the field of regenerative medicine, tissue engineering has emerged as a promising concept, and several methods of bone engineering are currently under investigation. A growth factor-based approach utilizing bone morphogenetic proteins (BMPs) has demonstrated stimulatory effects on cranial bone and defect repair. When combined with cell-based and matrix-based models, regenerative goals can be optimized. This manuscript intends to review recent investigations of tissue engineering models used for the repair of craniofacial defects with a focus on the role of BMPs, scaffold materials, and novel cell lines. When sufficient autologous bone is not available, safe and effective strategies to engineer bone would allow the surgeon to meet the reconstructive goals of the craniofacial skeleton. PMID:26389027

  7. 30 CFR 56.7002 - Equipment defects.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Equipment defects. 56.7002 Section 56.7002 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Drilling and Rotary...

  8. 30 CFR 56.7002 - Equipment defects.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Equipment defects. 56.7002 Section 56.7002 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Drilling and Rotary...

  9. 30 CFR 56.7002 - Equipment defects.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Equipment defects. 56.7002 Section 56.7002 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Drilling and Rotary...

  10. 7 CFR 52.3761 - Defects.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Defects. 52.3761 Section 52.3761 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946 PROCESSED FRUITS AND...

  11. 30 CFR 56.7002 - Equipment defects.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Equipment defects. 56.7002 Section 56.7002 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Drilling and Rotary...

  12. 7 CFR 51.2740 - Minor defects.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Minor defects. 51.2740 Section 51.2740 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946 FRESH FRUITS, VEGETABLES...

  13. 7 CFR 51.2762 - Minor defects.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Minor defects. 51.2762 Section 51.2762 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946 FRESH FRUITS, VEGETABLES...

  14. 30 CFR 56.7002 - Equipment defects.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Equipment defects. 56.7002 Section 56.7002 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Drilling and Rotary...

  15. 7 CFR 51.2720 - Minor defects.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Minor defects. 51.2720 Section 51.2720 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946 FRESH FRUITS, VEGETABLES...

  16. 7 CFR 51.1565 - Internal defects.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Internal defects. 51.1565 Section 51.1565 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946 AND THE EGG...

  17. 7 CFR 51.1565 - Internal defects.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Internal defects. 51.1565 Section 51.1565 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946 FRESH FRUITS, VEGETABLES...

  18. 7 CFR 51.1565 - Internal defects.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Internal defects. 51.1565 Section 51.1565 Agriculture..., CERTIFICATION, AND STANDARDS) United States Standards for Grades of Potatoes 1 Definitions § 51.1565 Internal.... Occurring entirely within the vascular ring Hollow Heart or Hollow Heart with Discoloration Area...

  19. 7 CFR 51.2659 - Condition defects.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Condition defects. 51.2659 Section 51.2659 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing..., CERTIFICATION, AND STANDARDS) United States Standards for Grades for Sweet Cherries 1 Definitions §...

  20. Bulk and defect properties of ordered intermetallics

    SciTech Connect

    Fu, C.L.; Yoo, M.H.

    1993-12-31

    First-principles calculations based on the local-density-functional theory have been used to investigate the factors governing strength of ordered intermetallic alloys. Unlike Ni{sub 3}Al, calculated elastic constants and shear fault energies indicate anomalous yield strength behavior is not likely to occur in Ni{sub 3}Si. This suggests the inadequacy of cross-slip-pinning model to explain the strength anomaly in the L1{sub 2} structure. For strongly ordered NiAl, the defect structure is dominated by two types of defects -- monovacancies on the Ni sites and substitutional antisite defects on the Al sites. By contrast, for Ni{sub 3}Al, absence of structural vacancies and deviations from stoichiometry are accommodated by substitutional antisite defects on both sublattices. Intrinsic strengthening mechanisms in TiAl are discussed in terms of calculated elastic constants and shear fault energies. Because of reduced fault energies at the {gamma}/{alpha}{sub 2} interface, slip and twinning contribute significantly to high shear deformation of the lamellar structure.

  1. 49 CFR 215.105 - Defective axle.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., DEPARTMENT OF TRANSPORTATION RAILROAD FREIGHT CAR SAFETY STANDARDS Freight Car Components Suspension System § 215.105 Defective axle. A railroad may not place or continue in service a car, if— (a) An axle on the car has a crack or is broken; (b) An axle on the car has a gouge in the surface that is— (1)...

  2. 49 CFR 215.105 - Defective axle.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., DEPARTMENT OF TRANSPORTATION RAILROAD FREIGHT CAR SAFETY STANDARDS Freight Car Components Suspension System § 215.105 Defective axle. A railroad may not place or continue in service a car, if— (a) An axle on the car has a crack or is broken; (b) An axle on the car has a gouge in the surface that is— (1)...

  3. 49 CFR 215.105 - Defective axle.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., DEPARTMENT OF TRANSPORTATION RAILROAD FREIGHT CAR SAFETY STANDARDS Freight Car Components Suspension System § 215.105 Defective axle. A railroad may not place or continue in service a car, if— (a) An axle on the car has a crack or is broken; (b) An axle on the car has a gouge in the surface that is— (1)...

  4. 49 CFR 215.123 - Defective couplers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., DEPARTMENT OF TRANSPORTATION RAILROAD FREIGHT CAR SAFETY STANDARDS Freight Car Components Draft System § 215.123 Defective couplers. A railroad may not place or continue in service a car, if— (a) The car is... automatically with the adjacent car; (b) The car has a coupler that has a crack in the highly stressed...

  5. Condensation of topological defects and confinement

    NASA Astrophysics Data System (ADS)

    Gaete, Patricio; Wotzasek, Clovis

    2004-11-01

    We study the static quantum potential for a theory of antisymmetric tensor fields that results from the condensation of topological defects, within the framework of the gauge-invariant but path-dependent variables formalism. Our calculations show that the interaction energy is the sum of a Yukawa and a linear potentials, leading to the confinement of static probe charges.

  6. Defect-free ultrahigh flux asymmetric membranes

    DOEpatents

    Pinnau, Ingo; Koros, William J.

    1990-01-01

    Defect-free, ultrahigh flux integrally-skinned asymmetric membranes having extremely thin surface layers (<0.2 .mu.m) comprised of glassy polymers are disclosed. The membranes are formed by casting an appropriate drope followed by forced convective evaporation of solvent to obtain a dry phase separated asymmetrical structure. The structure is then washed in a precipitation liquid and dried.

  7. Shock-induced defects in bulk materials

    SciTech Connect

    Gray, G.T.

    1998-03-01

    In this paper examples of the shock-induced defects produced during shock compression which correlate with microstructure/mechanical property changes induced in materials due to shock prestraining are discussed. The characteristics of the shock impulse(peak shock pressure, pulse duration, and rarefaction rate) imparted to the material under investigation and the shock-induced defects produced in numerous metals and alloys are compared with their deformation behavior at ordinary rates of deformation. Examples of the range of defects observed in shock-recovered metals and alloys, include: dislocations, deformation twins, point defects, and residual metastable remnants from pressure-induced phase transformations. Results concerning the influence of interstitial content on the propensity of {omega}-phase formation and its structure in high-purity and A-7O Ti are presented. The influence of shock-wave deformation on the phase stability and substructure evolution of high-purity (low-interstitial) titanium and A-7O (3,700 ppm oxygen) titanium were probed utilizing real-time velocity interferometry (VISAR) and soft shock-recovery techniques. Suppression of the {alpha}-{omega} pressure-induced phase transformation in A-70 Ti, containing a high interstitial oxygen content, is seen to simultaneously correspond with the suppression of deformation twinning.

  8. Annihilation of defects in liquid crystals

    NASA Astrophysics Data System (ADS)

    Svetec, M.; Ambrožič, M.; Kralj, S.

    The annihilation of defect is studied theoretically in liquid crystals (LCs). We consider the annihilation of point disclinations in nematic and line edge dislocations in smectic A LC phase, respectively. We stress qualitative similarities in these processes. The whole annihilation regime is taken into account, consisting of the pre-collision, collision, and post-collision stage.

  9. Thermal defects in B2 iron aluminide

    SciTech Connect

    Collins, G.S.; Peng, L.S.J.; Wei, M.

    1999-07-01

    Thermal defects in B2 FeAl samples with compositions between 49.5 and 54.7 at.% Fe were investigated using perturbed angular correlation of gamma rays (PAC). Vacancies on the Fe-sublattice were detected through quadrupole interactions induced at adjacent {sup 111}In/Cd probe atoms on the Al-sublattice. Five high-frequency quadrupole-interaction signals were detected (greater than 50 Mrad/s) that are attributed to complexes involving 1, 2, 3, 4 and (with less certainty) 5 Fe-vacancies in the first neighbor shells of the probes. These attribution are based on (1) a comparison between measured quadrupole interaction parameters and point-charge calculations of electric-field gradients for possible vacancy-probe complexes; and (2) numerical simulation of the evolution of site fractions of probes in the complexes at lower temperatures. Measurements were made at temperatures up to 950 C. Assuming that the equilibrium high-temperature is the triple defect (2 Fe-vacancies and one Fe-antisite atom), measurements over the range 600--900 C yield a formation enthalpy of 1.1(1) eV for the triple defect. Below about 600 C, Fe-vacancies are quenched-in with a fractional concentration of the order of 1 at.% close to stoichiometry. However, quenched-in vacancies continue to jump over short distances and trap next to the impurity probes atoms in day-long measurements down to 200 C. Simulations of site fractions below 700 C were used to determine binding enthalpies of vacancies with probe complexes. Binding enthalpies obtained for the first four vacancies were 0.23, 0.23, 0.15 and 0.18 eV. Simulations in the range 200--700 C suggest a negative value for the formation entropy. The negative value indicates either that triple defects stiffen the B2 lattice or that repulsive defect-defect interactions become important at the high defect concentrations in FeAl.

  10. Thermographic Imaging of Defects in Anisotropic Composites

    NASA Technical Reports Server (NTRS)

    Plotnikov, Y. A.; Winfree, W. P.

    2000-01-01

    Composite materials are of increasing interest to the aerospace industry as a result of their weight versus performance characteristics. One of the disadvantages of composites is the high cost of fabrication and post inspection with conventional ultrasonic scanning systems. The high cost of inspection is driven by the need for scanning systems which can follow large curve surfaces. Additionally, either large water tanks or water squirters are required to couple the ultrasonics into the part. Thermographic techniques offer significant advantages over conventional ultrasonics by not requiring physical coupling between the part and sensor. The thermographic system can easily inspect large curved surface without requiring a surface following scanner. However, implementation of Thermal Nondestructive Evaluations (TNDE) for flaw detection in composite materials and structures requires determining its limit. Advanced algorithms have been developed to enable locating and sizing defects in carbon fiber reinforced plastic (CFRP). Thermal Tomography is a very promising method for visualizing the size and location of defects in materials such as CFRP. However, further investigations are required to determine its capabilities for inspection of thick composites. In present work we have studied influence of the anisotropy on the reconstructed image of a defect generated by an inversion technique. The composite material is considered as homogeneous with macro properties: thermal conductivity K, specific heat c, and density rho. The simulation process involves two sequential steps: solving the three dimensional transient heat diffusion equation for a sample with a defect, then estimating the defect location and size from the surface spatial and temporal thermal distributions (inverse problem), calculated from the simulations.

  11. CDC Grand Rounds: Understanding the Causes of Major Birth Defects - Steps to Prevention.

    PubMed

    Simeone, Regina M; Feldkamp, Marcia L; Reefhuis, Jennita; Mitchell, Allen A; Gilboa, Suzanne M; Honein, Margaret A; Iskander, John

    2015-10-01

    Major birth defects (birth defects) are defined as structural abnormalities, present at birth, with surgical, medical, or cosmetic importance. Each year in the United States, 3% of live births (approximately 120,000 infants) have an identifiable structural birth defect. Examples of birth defects include neural tube defects, such as spina bifida; orofacial clefts; abdominal wall defects, such as gastroschisis; and congenital heart defects, such as hypoplastic left heart syndrome. Collectively, congenital heart defects are the most common birth defects (27%), followed by musculoskeletal defects (18%), genitourinary defects (15%), orofacial defects (5%), and neural tube defects (2%). PMID:26447345

  12. Automatic classification and accurate size measurement of blank mask defects

    NASA Astrophysics Data System (ADS)

    Bhamidipati, Samir; Paninjath, Sankaranarayanan; Pereira, Mark; Buck, Peter

    2015-07-01

    A blank mask and its preparation stages, such as cleaning or resist coating, play an important role in the eventual yield obtained by using it. Blank mask defects' impact analysis directly depends on the amount of available information such as the number of defects observed, their accurate locations and sizes. Mask usability qualification at the start of the preparation process, is crudely based on number of defects. Similarly, defect information such as size is sought to estimate eventual defect printability on the wafer. Tracking of defect characteristics, specifically size and shape, across multiple stages, can further be indicative of process related information such as cleaning or coating process efficiencies. At the first level, inspection machines address the requirement of defect characterization by detecting and reporting relevant defect information. The analysis of this information though is still largely a manual process. With advancing technology nodes and reducing half-pitch sizes, a large number of defects are observed; and the detailed knowledge associated, make manual defect review process an arduous task, in addition to adding sensitivity to human errors. Cases where defect information reported by inspection machine is not sufficient, mask shops rely on other tools. Use of CDSEM tools is one such option. However, these additional steps translate into increased costs. Calibre NxDAT based MDPAutoClassify tool provides an automated software alternative to the manual defect review process. Working on defect images generated by inspection machines, the tool extracts and reports additional information such as defect location, useful for defect avoidance[4][5]; defect size, useful in estimating defect printability; and, defect nature e.g. particle, scratch, resist void, etc., useful for process monitoring. The tool makes use of smart and elaborate post-processing algorithms to achieve this. Their elaborateness is a consequence of the variety and

  13. The role of defects in laser damage of multilayer coatings

    SciTech Connect

    Kozlowski, M.R.; Chow, R.

    1993-12-21

    Laser induced damage to optical coatings is generally a localized phenomenon associated with coating defects. The most common of the defect types are the well-known nodule defect. This paper reviews the use of experiments and modeling to understand the formation of these defects and their interaction with laser light. Of particular interest are efforts to identify which defects are most susceptible to laser damage. Also discussed are possible methods for stabilizing these defects (laser conditioning) or preventing their initiation (source stabilization, spatter particle trapping).

  14. Carrier scattering by native defects in heavily doped semiconductors

    SciTech Connect

    Walukiewicz, W. Materials and Chemical Sciences Division, Lawrence Berkeley Laboratory, 1 Cyclotron Road, Berkeley, CA )

    1990-05-15

    Calculations of the effect of charged native defects on carrier mobility in semiconductors are presented. The concentrations of native defects are calculated within the framework of the recently proposed amphoteric-native-defect model. The model provides a simple rule for identification of semiconductor systems in which defect scattering is important. It is shown that native-defect scattering is a dominant mechanism limiting electron mobilities in heavily doped {ital n}-type GaAs. It is also shown that native defects do not play any significant role in {ital p}-type GaAs.

  15. Charge storage in oxygen deficient phases of TiO2: defect Physics without defects.

    PubMed

    Padilha, A C M; Raebiger, H; Rocha, A R; Dalpian, G M

    2016-01-01

    Defects in semiconductors can exhibit multiple charge states, which can be used for charge storage applications. Here we consider such charge storage in a series of oxygen deficient phases of TiO2, known as Magnéli phases. These Magnéli phases (TinO2n-1) present well-defined crystalline structures, i.e., their deviation from stoichiometry is accommodated by changes in space group as opposed to point defects. We show that these phases exhibit intermediate bands with an electronic quadruple donor transitions akin to interstitial Ti defect levels in rutile TiO2. Thus, the Magnéli phases behave as if they contained a very large pseudo-defect density: ½ per formula unit TinO2n-1. Depending on the Fermi Energy the whole material will become charged. These crystals are natural charge storage materials with a storage capacity that rivals the best known supercapacitors. PMID:27364139

  16. Charge storage in oxygen deficient phases of TiO2: defect Physics without defects

    NASA Astrophysics Data System (ADS)

    Padilha, A. C. M.; Raebiger, H.; Rocha, A. R.; Dalpian, G. M.

    2016-07-01

    Defects in semiconductors can exhibit multiple charge states, which can be used for charge storage applications. Here we consider such charge storage in a series of oxygen deficient phases of TiO2, known as Magnéli phases. These Magnéli phases (TinO2n‑1) present well-defined crystalline structures, i.e., their deviation from stoichiometry is accommodated by changes in space group as opposed to point defects. We show that these phases exhibit intermediate bands with an electronic quadruple donor transitions akin to interstitial Ti defect levels in rutile TiO2. Thus, the Magnéli phases behave as if they contained a very large pseudo-defect density: ½ per formula unit TinO2n‑1. Depending on the Fermi Energy the whole material will become charged. These crystals are natural charge storage materials with a storage capacity that rivals the best known supercapacitors.

  17. Building capacity for birth defects surveillance in Africa: Implementation of an intermediate birth defects surveillance workshop

    PubMed Central

    Flores, Alina; Valencia, Diana; Sekkarie, Ahlia; Hillard, Christina L.; Williams, Jennifer; Groisman, Boris; Botto, Lorenzo D.; Peña-Rosas, Juan Pablo; Bauwens, Lieven; Mastroiacovo, Pierpaolo

    2016-01-01

    Each year around the world, it is estimated that 300,000 neonates are born with a neural tube defect. Many countries, however, are still lacking comprehensive birth defects surveillance registries. Comprehensive birth defects surveillance systems can help countries understand the magnitude and distribution of the problem. These systems can also provide information about biological, contextual, social and environmental determinants of birth defects. This information in turn can be used to identify effective and implementable solutions, and to evaluate prevention and management strategies to improve quality performance. This paper summarizes the development and implementation of an online pre-course training and in-person surveillance workshop conducted between 2014 December and 2015 March for representatives from six African countries. Feedback given by participants provided valuable lessons learned that can be applied to subsequent trainings and workshops. PMID:26753106

  18. Role of defect coordination environment on point defects formation energies in Ni-Al intermetallic alloys

    NASA Astrophysics Data System (ADS)

    Tennessen, Emrys; Rondinelli, James

    We present a relationship among the point defect formation energies and the bond strengths, lengths, and local coordination environment for Ni-Al intermetallic alloys based on density functional calculations, including Ni3Al, Ni5Al3, NiAl,Ni3Al4, Ni2Al3 and NiAl3. We find the energetic stability of vacancy and anti-site defects for the entire family can be attributed primarily to changes in interactions among first nearest neighbors, owing to spatially localized charge density reconstructions in the vicinity of the defect site. We also compare our interpretation of the local coordination environment with a DFT-based cluster expansion and discuss the performance of each approach in predicting defect stability in the Ni-Al system.

  19. Charge storage in oxygen deficient phases of TiO2: defect Physics without defects

    PubMed Central

    Padilha, A. C. M.; Raebiger, H.; Rocha, A. R.; Dalpian, G. M.

    2016-01-01

    Defects in semiconductors can exhibit multiple charge states, which can be used for charge storage applications. Here we consider such charge storage in a series of oxygen deficient phases of TiO2, known as Magnéli phases. These Magnéli phases (TinO2n−1) present well-defined crystalline structures, i.e., their deviation from stoichiometry is accommodated by changes in space group as opposed to point defects. We show that these phases exhibit intermediate bands with an electronic quadruple donor transitions akin to interstitial Ti defect levels in rutile TiO2. Thus, the Magnéli phases behave as if they contained a very large pseudo-defect density: ½ per formula unit TinO2n−1. Depending on the Fermi Energy the whole material will become charged. These crystals are natural charge storage materials with a storage capacity that rivals the best known supercapacitors. PMID:27364139

  20. Behavior of chemically amplified resist defects in TMAH solution: III

    NASA Astrophysics Data System (ADS)

    Ono, Yuko; Shimoaoki, Takeshi; Naito, Ryoichiro; Kitano, Junichi

    2004-05-01

    As the minimum feature size of electronic devices shrinks to less than 0.25 μm, it is critically important that we reduce the defects that occur in lithography processes. Moreover, as the defects to be controlled become ever smaller, this makes them increasingly difficult to detect by conventional fault detection equipment. In order to detect these minute defects in the context of shrinking device geometries, it is essential that we develop a clear understanding of the behavior of micro defects in developer. In principle, there are three ways in which these defects might be dealt with: (1) defects can be prevented from occurring in the first place, (2) defects can be prevented from adhering to the device, or (3) defects can be eliminated after they occur. Our recent work has mainly been concerned with the first and most effective approach of preventing defects from occurring in the first place, and this motivated the present study to investigate the mechanisms by which defects occur. We believe that defects occur in chemically amplified (CA) resists that are insufficiently unprotected at boundary regions between unexposed and exposed areas or in unexposed areas, so that the de-protection reaction in the resist suns to different degrees of completion due to varying exposure doses. In this study we investigate the number of defects in various developers, and determine the size distribution of the defects. Based on analysis of the behavior of defects from their size distribution in develop we conclude that: (1) the size of defects increases when the exposure dose is reduced by appropriate Eops, (2) defects originate in the boundary area between unexposed and exposed areas, and (3) a portion of CA resist polymer that is insufficiently deprotected is dispersed in the developer, coalesces and is deposited in a form that is not very soluble, and is manifested as relatively large particle defects.

  1. EUV actinic brightfield mask microscopy for predicting printed defect images

    NASA Astrophysics Data System (ADS)

    Goldberg, Kenneth; Benk, Markus P.; Wojdyla, Antoine; Verduijn, Erik; Wood, Obert R.; Mangat, Pawitter

    2015-10-01

    Improving our collective understanding of extreme ultraviolet (EUV) photomask defects and the imaging properties of available defect imaging tools is essential for improving EUV mask defectivity, defect repair and mitigation, and for high-level strategic decision-making. In this work, we perform a qualitative comparison of twenty-five defects imaged with mask scanning electron microscopy (SEM), EUV actinic mask imaging, and wafer SEM imaging. All but two of the defect locations were first identified by non-actinic mask blank inspection, prior to patterning. The others were identified as repeating defects on the wafer. We find that actinic defect imaging is predictive of the wafer prints, with small-scale features clearly replicated. While some mask defect SEM images match the wafer prints, others print with a larger outline indicating the presence of sub-surface disruptions hidden from the SEM's view. Fourteen other defects were subjected to an aerial image phase measurement method called Fourier Ptychography (FP). Although phase shifts were observed in the larger defects, the smaller defects in the dataset showed no significant phase shifting. We attribute this discrepancy to non-actinic mask blank inspection's limited ability to detect small phase defects under normal operating conditions.

  2. Extreme ultraviolet multilayer defect analysis and geometry reconstruction

    NASA Astrophysics Data System (ADS)

    Xu, Dongbo; Evanschitzky, Peter; Erdmann, Andreas

    2016-01-01

    This paper proposes a method for the characterization of multilayer defects from extreme ultraviolet (EUV) projection images at different focus positions. The transport-of-intensity equation is applied to retrieve the phase distribution of the reflected light in the vicinity of the defect. The defect-induced intensity and phase modifications and their dependency from defect geometry parameters are analyzed by several selected optical properties of multilayer defect. To reconstruct the defect geometry parameters from the intensity and phase of a defect, a principal component analysis (PCA) is employed to parameterize the intensity and phase distributions into principal component coefficients. In order to construct the base functions of the PCA, a combination of a reference multilayer defect and appropriate pupil filters is introduced to obtain the designed sets of intensity and phase distributions. Finally, an artificial neural network is applied to correlate the principal component coefficients of the intensity and the phase of the defect with the defect geometry parameters and to reconstruct the unknown defect geometry parameters. The performance of the proposed approach is evaluated both for mask blank defects and for defects in the vicinity of an absorber pattern.

  3. Computational mask defect review for contamination and haze inspections

    NASA Astrophysics Data System (ADS)

    Morgan, Paul; Rost, Daniel; Price, Daniel; Corcoran, Noel; Satake, Masaki; Hu, Peter; Peng, Danping; Yonenaga, Dean; Tolani, Vikram; Wolf, Yulian; Shah, Pinkesh

    2013-09-01

    As optical lithography continues to extend into sub-0.35 k1 regime, mask defect inspection and subsequent review has become tremendously challenging, and indeed the largest component to mask manufacturing cost. The routine use of various resolution enhancement techniques (RET) have resulted in complex mask patterns, which together with the need to detect even smaller defects due to higher MEEFs, now requires an inspection engineer to use combination of inspection modes. This is achieved in 193nm AeraTM mask inspection systems wherein masks are not only inspected at their scanner equivalent aerial exposure conditions, but also at higher Numerical Aperture resolution, and special reflected-light, and single-die contamination modes, providing better coverage over all available patterns, and defect types. Once the required defects are detected by the inspection system, comprehensively reviewing and dispositioning each defect then becomes the Achilles heel of the overall mask inspection process. Traditionally, defects have been reviewed manually by an operator, which makes the process error-prone especially given the low-contrast in the convoluted aerial images. Such manual review also limits the quality and quantity of classifications in terms of the different types of characterization and number of defects that can practically be reviewed by a person. In some ways, such manual classification limits the capability of the inspection tool itself from being setup to detect smaller defects since it often results in many more defects that need to be then manually reviewed. Paper 8681-109 at SPIE Advanced Lithography 2013 discussed an innovative approach to actinic mask defect review using computational technology, and focused on Die-to-Die transmitted aerial and high-resolution inspections. In this approach, every defect is characterized in two different ways, viz., quantitatively in terms of its print impact on wafer, and qualitatively in terms of its nature and origin in

  4. Analysis of submicron defects using an SEM-Auger defect review tool

    SciTech Connect

    Childs, Kenton D.; Watson, David G.; Paul, Dennis F.; Clough, Stephen P.

    1998-11-24

    The challenges associated with analyzing semiconductor defects become greater as the device design rule decreases. According to the SIA National Technology Roadmap for Semiconductors, the current metrology requirement for particle analysis is 90 nm with the need to analyze 75 nm particles by the year 2001. These dimensional requirements are beyond the typical capabilities of current SEM/EDX defect review tools. Auger Electron Spectroscopy is a powerful method for measuring the surface composition of localized regions, and has been identified in the SIA roadmap as a primary technique for particle analysis. The ability of a state-of-the-art Auger defect review tool (DRT) to provide secondary electron and high spatial resolution elemental images is particularly effective in characterizing the often complex structure of semiconductor defects. Examples of Auger analysis from defects found at various process steps, on both unpatterned and patterned whole wafers, are shown. These examples highlight the ability of Auger to analyze both thin and laterally small or complex defects.

  5. Porous nematic microfluidics for generation of umbilic defects and umbilic defect lattices

    NASA Astrophysics Data System (ADS)

    Aplinc, Jure; Morris, Stephen; Ravnik, Miha

    2016-06-01

    We demonstrate that porous nematic microfluidics is a potential route for the generation of nematic umbilic defects and regular umbilic defect lattices. By using numerical modeling we show that the mutual (backflow) coupling between the flow velocity and the orientation director field of the nematic liquid crystal leads to the formation of positive umbilic defects at local peaks and to the formation of negative umbilic defects at the local saddles in the flow profile. The number of flow peaks and the index of the flow saddles (i.e., the number of the valleys) are shown to be directly related to the strength of the umbilic defect, effectively relating the two fields at the geometrical level. The regular arrangement of the barriers in the porous channels is demonstrated to lead to the formation of regular lattices of umbilic defects, including square, triangular, and even kagome lattices. Experimental realization of such systems is discussed, with particular focus on microfluidic-tunable birefringent photonic band structures and lattices.

  6. Defect characterisation based on heat diffusion using induction thermography testing

    NASA Astrophysics Data System (ADS)

    He, Yunze; Pan, Mengchun; Luo, Feilu

    2012-10-01

    Pulsed eddy current (PEC) thermography (a.k.a. induction thermography) has been successfully applied to detect defects (corrosion, cracks, impact, and delamination) in metal alloy and carbon fiber reinforced plastic. During these applications, the defect detection mechanism is mainly investigated based on the eddy current interaction with defect. In this paper, defect characterisation for wall thinning defect and inner defect in steel is investigated based on heat diffusion. The paper presents the PEC thermography testing, which integrates the reflection mode and transmission mode by means of configuring two cameras on both sides of sample. The defect characterisation methods under transmission mode and reflection mode are investigated and compared through 1D analytical analysis, 3D numerical studies, and experimental studies. The suitable detection mode for wall thinning and inner defects quantification is concluded.

  7. Production of EUV mask blanks with low killer defects

    NASA Astrophysics Data System (ADS)

    Antohe, Alin O.; Kearney, Patrick; Godwin, Milton; He, Long; John Kadaksham, Arun; Goodwin, Frank; Weaver, Al; Hayes, Alan; Trigg, Steve

    2014-04-01

    For full commercialization, extreme ultraviolet lithography (EUVL) technology requires the availability of EUV mask blanks that are free of defects. This remains one of the main impediments to the implementation of EUV at the 22 nm node and beyond. Consensus is building that a few small defects can be mitigated during mask patterning, but defects over 100 nm (SiO2 equivalent) in size are considered potential "killer" defects or defects large enough that the mask blank would not be usable. The current defect performance of the ion beam sputter deposition (IBD) tool will be discussed and the progress achieved to date in the reduction of large size defects will be summarized, including a description of the main sources of defects and their composition.

  8. Detection of a Heart Defect in the Fetus

    MedlinePlus

    ... Heart Defects • Home • About Congenital Heart Defects • The Impact of Congenital Heart ... About Heart Rate (Pulse) 4 What are the Symptoms of High Blood Pressure? 5 How to Eat Healthy 6 ...

  9. Zika Virus Causes Brain Defects in Babies: CDC

    MedlinePlus

    ... medlineplus/news/fullstory_158287.html Zika Virus Causes Brain Defects in Babies: CDC Agency says evidence confirms ... definite and direct cause of microcephaly and other brain-related birth defects, U.S. health officials announced Wednesday. " ...

  10. Defect annihilation at grain boundaries in alpha-Fe

    PubMed Central

    Di Chen; Wang, Jing; Chen, Tianyi; Shao, Lin

    2013-01-01

    Understanding radiation responses of Fe-based metals is essential to develop radiation tolerant steels for longer and safer life cycles in harsh reactor environments. Nanograined metals have been explored as self-healing materials due to point-defect recombination at grain boundaries. The fundamental defect-boundary interactions, however, are not yet well understood. We discover that the interactions are always mediated by formation and annealing of chain-like defects, which consist of alternately positioned interstitials and vacancies. These chain-like defects are closely correlated to the patterns of defect formation energy minima on the grain boundary, which depend on specific boundary configurations. Through chain-like defects, a point defect effectively translates large distances, to annihilate with its opposite, thus grain boundaries act as highly efficient defect sinks that cannot saturate under extreme radiation conditions. PMID:23519086

  11. Defect annihilation at grain boundaries in alpha-Fe.

    PubMed

    Chen, Di; Wang, Jing; Chen, Tianyi; Shao, Lin

    2013-01-01

    Understanding radiation responses of Fe-based metals is essential to develop radiation tolerant steels for longer and safer life cycles in harsh reactor environments. Nanograined metals have been explored as self-healing materials due to point-defect recombination at grain boundaries. The fundamental defect-boundary interactions, however, are not yet well understood. We discover that the interactions are always mediated by formation and annealing of chain-like defects, which consist of alternately positioned interstitials and vacancies. These chain-like defects are closely correlated to the patterns of defect formation energy minima on the grain boundary, which depend on specific boundary configurations. Through chain-like defects, a point defect effectively translates large distances, to annihilate with its opposite, thus grain boundaries act as highly efficient defect sinks that cannot saturate under extreme radiation conditions. PMID:23519086

  12. Lower Dimension Vacuum Defects in Lattice Yang-Mills Theory

    SciTech Connect

    Zakharov, V.I.

    2005-04-01

    We overview lattice data on d = 0, 1, 2, 3 dimensional vacuum defects in lattice four-dimensional SU(2) (SU(3)) gluodynamics. In all the cases, defects have a total volume which scales in physical units (with zero fractal dimension). In the case of d = 1, 2, the defects are distinguished by ultraviolet divergent non-Abelian action as well. This sensitivity to the ultraviolet scale allows us to derive strong constraints from the continuum theory on the properties of the defects, which turn out to be satisfied by the lattice data. We discuss a classification scheme of the defects which allows us to (at least) visualize the defect properties in a simple and unified way. A not-yet-checked relation of the defects to the spontaneous chiral symmetry breaking is suggested by the scheme. Finally, we present some arguments that the defects considered could become fundamental variables of a dual formulation of the theory.

  13. Are There Disorders or Conditions Associated with Neural Tube Defects?

    MedlinePlus

    ... Publications Are there disorders or conditions associated with neural tube defects? Skip sharing on social media links Share this: Page Content Infants born with neural tube defects that are not immediately fatal may ...

  14. 7 CFR 52.3187 - Definitions and explanations of defects.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... flesh, or both, of the prune. (h) Insect injury. “Insect injury” means healed or unhealed surface...) Other means. “Other means” includes damage by any injury or defect or group of defects not...

  15. Study Explores Mechanism Between Zika Virus, Birth Defects

    MedlinePlus

    ... fullstory_158048.html Study Explores Mechanism Between Zika Virus, Birth Defects Protein on fetal stem cells provides ... Scientists say they've discovered how the Zika virus might cause severe brain and eye birth defects. ...

  16. Defect characterisation based on heat diffusion using induction thermography testing.

    PubMed

    He, Yunze; Pan, Mengchun; Luo, Feilu

    2012-10-01

    Pulsed eddy current (PEC) thermography (a.k.a. induction thermography) has been successfully applied to detect defects (corrosion, cracks, impact, and delamination) in metal alloy and carbon fiber reinforced plastic. During these applications, the defect detection mechanism is mainly investigated based on the eddy current interaction with defect. In this paper, defect characterisation for wall thinning defect and inner defect in steel is investigated based on heat diffusion. The paper presents the PEC thermography testing, which integrates the reflection mode and transmission mode by means of configuring two cameras on both sides of sample. The defect characterisation methods under transmission mode and reflection mode are investigated and compared through 1D analytical analysis, 3D numerical studies, and experimental studies. The suitable detection mode for wall thinning and inner defects quantification is concluded. PMID:23126785

  17. Vorticity, defects and correlations in active turbulence

    PubMed Central

    Thampi, Sumesh P.; Golestanian, Ramin; Yeomans, Julia M.

    2014-01-01

    We describe a numerical investigation of a continuum model of an active nematic, concentrating on the regime of active turbulence. Results are presented for the effect of three parameters, activity, elastic constant and rotational diffusion constant, on the order parameter and flow fields. Defects and distortions in the director field act as sources of vorticity, and thus vorticity is strongly correlated to the director field. In particular, the characteristic length of decay of vorticity and order parameter correlations is controlled by the defect density. By contrast, the decay of velocity correlations is determined by a balance between activity and dissipation. We highlight the role of microscopic flow generation mechanisms in determining the flow patterns and characteristic scales of active turbulence and contrast the behaviour of extensile and contractile active nematics. PMID:25332382

  18. Excess Oxygen Defects in Layered Cuprates

    DOE R&D Accomplishments Database

    Lightfoot, P.; Pei, S. Y.; Jorgensen, J. D.; Manthiram, A.; Tang, X. X.; Goodenough, J. B.

    1990-09-01

    Neutron powder diffraction has been used to study the oxygen defect chemistry of two non-superconducting layered cuprates, La{sub 1. 25}Dy{sub 0.75}Cu{sub 3.75}F{sub 0.5}, having a T{sup {asterisk}}- related structure, and La{sub 1.85}Sr{sub 1.15}Cu{sub 2}O{sub 6.25}, having a structure related to that of the newly discovered double-layer superconductor La{sub 2-x}Sr{sub x}CaCu{sub 2}O{sub 6}. The role played by oxygen defects in determining the superconducting properties of layered cuprates is discussed.

  19. Birth defects: Risk factors and consequences

    PubMed Central

    Oliveira, Camila Ive Ferreira; Fett-Conte, Agnes Cristina

    2013-01-01

    Birth defects (BDs) or congenital anomalies include all structural and functional alterations in embryonic or fetal development resulting from genetic, environmental or unknown causes, which result in physical and/or mental impairment. BDs occur in about 3% of newborn babies and in most cases of pregnancy loss. BDs are a very complex and heterogeneous group of single or multiple changes that, in most cases, are of unknown etiology. Among the risk factors are advanced maternal and paternal ages, parental consanguinity, teratogenic agents such as infectious agents and drugs, and poor nutrition, in particular folic acid deficiency. One of the consequences of these defects is the high death rate within the first year of life. Information on BDs is becoming increasingly more important throughout the world so that preventive measures can be taken. Knowledge of BDs enables the development of therapeutic and preventive strategies besides adequate genetic counseling.

  20. Multichannel quantum defect theory for polar molecules

    NASA Astrophysics Data System (ADS)

    Elfimov, Sergei V.; Dorofeev, Dmitrii L.; Zon, Boris A.

    2014-02-01

    Our work is devoted to developing a general approach for nonpenetrating Rydberg states of polar molecules. We propose a method to estimate the accuracy of calculation of their wave functions and quantum defects. Basing on this method we estimate the accuracy of Born-Oppenheimer (BO) and inverse Born-Oppenheimer (IBO) approximations for these states. This estimation enables us to determine the space and energy regions where BO and IBO approximations are valid. It depends on the interplay between l coupling (due to dipole potential of the core) and l uncoupling (due to rotation the core). Next we consider the intermediate region where both BO and IBO are not valid. For this intermediate region we propose a modification of Fano's multichannel quantum defect theory to match BO and IBO wave functions and show that it gives more reliable results. They are demonstrated on the example of SO molecule.

  1. Defect and recognition in Sophocles' Oedipus Rex.

    PubMed

    Whitman-Raymond, Lee

    2005-12-01

    This paper explores the relationships between experienced defect and the subsequent shame and longing for recognition. A clinical vignette is presented in which a young woman sought treatment for her infidelity to her husband: a behavior she found totally mystifying and deeply troubling. Using Bollas' concept of "the unthought known," parallels are drawn between this patient, who was adopted at 2 weeks of age, and Oedipus' experience of knowing and not knowing his fate. A case is made for the idea that we both avoid and seek to know what is unbearable about ourselves, including our sense of defects. One motivation for this is the longing to be seen, recognized, known, and, finally, know one's self. PMID:16328074

  2. Nanoscale defect detection by heterodyne interferometry

    SciTech Connect

    Lin Haoshan; Li Yuhe; Wang Dongsheng; Tong Xiaolei; Liu Mei

    2009-03-10

    We construct an instrument that facilitates the measurement of nanoscale defects. It is based on heterodyne interferometry with phase measurement that utilizes a polarizing beam splitter to form a measuring signal and an oscillating cantilever tip that acts as a scanning probe to get the measurement values of sample topography. The dependence of the tip displacement on the variation of tip-sample distance and the comb scanning of the sample topography are investigated by experiments. The results prove that the tip displacement increases and is enough to be discriminated in various positions where the sample is approached. The system has been successfully utilized to measure the defect characterization by measuring the pitch of the standard sample. The results also show that the heterodyne system has good repeatability, a large measurement range, and high accuracy, with a measurement stability of 0.5 nm.

  3. Defect structure of EFG silicon ribbon

    NASA Astrophysics Data System (ADS)

    Strunk, H.; Cunningham, B.; Ast, D.

    1980-12-01

    The defect structure of EFG ribbons was studied using EBIC, TEM and HVEM. By imaging the same areas in EBIC and HVEM, a direct correlation between the crystallographic nature of defects and their electrical properties was obtained. (1) Partial dislocations at coherent twin boundaries may or may not be electrically active. Since no microprecipitates were observed at these dislocations it is likely that the different electrical activity is a consequence of the different dislocation core structures. (2) 2nd order twin joins were observed which followed the same direction as the coherent first order twins normally associated with EFG ribbons. These 2nd order twin joins are in all cases strongly electrically active. EFG ribbons contain high concentrations of carbon. Since no evidence of precipitation was found with TEM it is suggested that the carbon may be incorporated into the higher order twin boundaries now known to exist in EFG ribbons.

  4. Nonlinear ultrasonic scanning to detect material defects

    NASA Technical Reports Server (NTRS)

    Yost, William T. (Inventor); Cantrell, John H. (Inventor)

    1998-01-01

    A method and system are provided to detect defects in a material. Waves of known frequency(ies) are mixed at an interaction zone in the material. As a result, at least one of a difference wave and a sum wave are generated in the interaction zone. The difference wave occurs at a difference frequency and the sum wave occurs at a sum frequency. The amplitude of at least one nonlinear signal based on the sum and/or difference waves is then measured. The nonlinear signal is defined as the amplitude of one of the difference wave and sum wave relative to the product of the amplitude of the surface waves. The amplitude of the nonlinear signal is an indication of defects (e.g., dislocation dipole density) in the interaction zone.

  5. Transport on a lattice with dynamical defects

    NASA Astrophysics Data System (ADS)

    Turci, Francesco; Parmeggiani, Andrea; Pitard, Estelle; Romano, M. Carmen; Ciandrini, Luca

    2013-01-01

    Many transport processes in nature take place on substrates, often considered as unidimensional lanes. These unidimensional substrates are typically nonstatic: Affected by a fluctuating environment, they can undergo conformational changes. This is particularly true in biological cells, where the state of the substrate is often coupled to the active motion of macromolecular complexes, such as motor proteins on microtubules or ribosomes on mRNAs, causing new interesting phenomena. Inspired by biological processes such as protein synthesis by ribosomes and motor protein transport, we introduce the concept of localized dynamical sites coupled to a driven lattice gas dynamics. We investigate the phenomenology of transport in the presence of dynamical defects and find a regime characterized by an intermittent current and subject to severe finite-size effects. Our results demonstrate the impact of the regulatory role of the dynamical defects in transport not only in biology but also in more general contexts.

  6. Defect structure of EFG silicon ribbon

    NASA Technical Reports Server (NTRS)

    Strunk, H.; Cunningham, B.; Ast, D.

    1980-01-01

    The defect structure of EFG ribbons was studied using EBIC, TEM and HVEM. By imaging the same areas in EBIC and HVEM, a direct correlation between the crystallographic nature of defects and their electrical properties was obtained. (1) Partial dislocations at coherent twin boundaries may or may not be electrically active. Since no microprecipitates were observed at these dislocations it is likely that the different electrical activity is a consequence of the different dislocation core structures. (2) 2nd order twin joins were observed which followed the same direction as the coherent first order twins normally associated with EFG ribbons. These 2nd order twin joins are in all cases strongly electrically active. EFG ribbons contain high concentrations of carbon. Since no evidence of precipitation was found with TEM it is suggested that the carbon may be incorporated into the higher order twin boundaries now known to exist in EFG ribbons.

  7. Biomimetic biphasic scaffolds for osteochondral defect repair

    PubMed Central

    Li, Xuezhou; Ding, Jianxun; Wang, Jincheng; Zhuang, Xiuli; Chen, Xuesi

    2015-01-01

    The osteochondral defects caused by vigorous trauma or physical disease are difficult to be managed. Tissue engineering provides a possible option to regenerate the damaged osteochondral tissues. For osteochondral reconstruction, one intact scaffold should be considered to support the regeneration of both cartilage and subchondral bone. Therefore, the biphasic scaffolds with the mimic structures of osteochondral tissues have been developed to close this chasm. A variety of biomimetic bilayer scaffolds fabricated from natural or synthetic polymers, or the ones loading with growth factors, cells, or both of them make great progresses in osteochondral defect repair. In this review, the preparation and in vitro and/or in vivo verification of bioinspired biphasic scaffolds are summarized and discussed, as well as the prospect is predicted. PMID:26816644

  8. Defective Reduction in Automotive Headlining Manufacturing Process

    NASA Astrophysics Data System (ADS)

    Rittichai, Saranya; Chutima, Parames

    2016-05-01

    In an automobile parts manufacturing company, currently the headlining process has a lot of wastes resulting in a high cost of quality per year. In this paper, the Six Sigma method is used to reduce the defects in the headlining process. Cause-and-effect matrix and failure mode and effect analysis (FMEA) were adopted to screen the factors that affect the quality of headlining. The 2k-1 fractional factorials design was also use to determine the potential preliminary root causes. The full factorial experiments was conducted to identify appropriate settings of the significant factors. The result showed that the process can reduce the defects of headlining from 12.21% to 6.95%

  9. Parallel transport and defects on nematic shells

    NASA Astrophysics Data System (ADS)

    Rosso, Riccardo; Virga, Epifanio G.; Kralj, Samo

    2012-11-01

    Nematic shells are thin films of nematic liquid crystal deposited on the boundary of colloidal particles, where liquid crystal molecules may freely glide, while remaining tangent to the surface substrate. The surface nematic order is described here by an appropriate tensor field Q, which vanishes wherever a defect occurs in the molecular order. We show how the classical concept of parallel transport on a manifold introduced by Levi-Civita can be adapted to this setting to define the topological charge m of a defect. We arrive at a simple formula to compute m from a generic representation of Q. In a number of separate appendices, we revisit in a unified language several, apparently disparate applications of Levi-Civita's parallel transport.

  10. CBED and LACBED characterization of crystal defects.

    PubMed

    Morniroli, J P

    2006-09-01

    Convergent-beam electron diffraction (CBED) obtained with a focused incident beam is well known for the identification of the point and space groups but it can also be used for the analysis of stacking faults and antiphase boundaries. Large-angle convergent-beam electron diffraction (LACBED) is performed with a large defocused incident beam and is well adapted to the characterization of most types of crystal defects: point defects, perfect and partial dislocations, stacking faults, antiphase boundaries and grain boundaries. Among the advantages of these methods with respect to the conventional transmission electron microscopy methods, are that one or few patterns are required for a full analysis and the interpretations are easy and unambiguous. The LACBED technique is particularly useful for the analysis of dislocations present in anisotropic and beam-sensitive materials. PMID:17059540

  11. Topological Point Defects in Relaxor Ferroelectrics

    NASA Astrophysics Data System (ADS)

    Nahas, Y.; Prokhorenko, S.; Kornev, I.; Bellaiche, L.

    2016-03-01

    First-principles-based effective Hamiltonian simulations are used to reveal the hidden connection between topological defects (hedgehogs and antihedgehogs) and relaxor behavior. Such defects are discovered to predominantly lie at the border of polar nanoregions in both Ba (Zr0.5 Ti0.5 )O3 (BZT) and Pb (Sc0.5 Nb0.5 )O3 (PSN) systems, and the temperature dependency of their density allows us to distinguish between noncanonical (PSN) and canonical (BZT) relaxor behaviors (via the presence or absence of a crossing of a percolation threshold). This density also possesses an inflection point at precisely the temperature for which the dielectric response peaks. Moreover, hedgehogs and antihedgehogs are found to be mobile excitations, and the dynamical nature of their annihilation is demonstrated (using simple hydrodynamical arguments) to follows laws, such as those of Vogel-Fulcher and Arrhenius, that are characteristic of dipolar relaxation kinetics of relaxor ferroelectrics.

  12. Topological Point Defects in Relaxor Ferroelectrics.

    PubMed

    Nahas, Y; Prokhorenko, S; Kornev, I; Bellaiche, L

    2016-03-25

    First-principles-based effective Hamiltonian simulations are used to reveal the hidden connection between topological defects (hedgehogs and antihedgehogs) and relaxor behavior. Such defects are discovered to predominantly lie at the border of polar nanoregions in both Ba(Zr_{0.5}Ti_{0.5})O_{3} (BZT) and Pb(Sc_{0.5}Nb_{0.5})O_{3} (PSN) systems, and the temperature dependency of their density allows us to distinguish between noncanonical (PSN) and canonical (BZT) relaxor behaviors (via the presence or absence of a crossing of a percolation threshold). This density also possesses an inflection point at precisely the temperature for which the dielectric response peaks. Moreover, hedgehogs and antihedgehogs are found to be mobile excitations, and the dynamical nature of their annihilation is demonstrated (using simple hydrodynamical arguments) to follows laws, such as those of Vogel-Fulcher and Arrhenius, that are characteristic of dipolar relaxation kinetics of relaxor ferroelectrics. PMID:27058101

  13. Lattice Strain Defects in a Ceria Nanolayer

    PubMed Central

    2016-01-01

    An ultrathin two-dimensional CeO2 (ceria) phase on a Cu(110) surface has been fabricated and fully characterized by high-resolution scanning tunneling microscopy, photoelectron spectroscopy, and density functional theory. The atomic lattice structure of the ceria/Cu(110) system is revealed as a hexagonal CeO2(111)-type monolayer separated from the Cu(110) surface by a partly disordered Cu–O intercalated buffer layer. The epitaxial coupling of the two-dimensional ceria overlayer to the Cu(110)-O surface leads to a nanoscopic stripe pattern, which creates defect regions of quasi-periodic lattice distortions. The symmetry and lattice mismatch at the interface is clarified to be responsible for the topographic stripe geometry and the related anisotropic strain defect regions at the ceria surface. This ceria monolayer is in a fully oxidized and thermodynamically stable state. PMID:26988695

  14. Defect junctions and domain wall dynamics

    SciTech Connect

    Avelino, P.P.; Oliveira, J.C.R.E.; Martins, C.J.A.P.; Menezes, J.; Menezes, R.

    2006-06-15

    We study a number of domain wall forming models where various types of defect junctions can exist. These illustrate some of the mechanisms that will determine the evolution of defect networks with junctions. Understanding these mechanisms is vital for a proper assessment of a number of cosmological scenarios: we will focus on the issue of whether or not cosmological frustrated domain wall networks can exist at all, but our results are also relevant for the dynamics of cosmic (super)strings, where junctions are expected to be ubiquitous. We also define and discuss the properties that would make up the ideal model in terms of hypothetical frustrated wall networks, and provide an explicit construction for such a model. We carry out a number of numerical simulations of the evolution of these networks, analyze and contrast their results, and discuss their implications for our no-frustration conjecture.

  15. Phonons, defects and optical damage in crystalline acetanilide

    NASA Astrophysics Data System (ADS)

    Kosic, Thomas J.; Hill, Jeffrey R.; Dlott, Dana D.

    1986-04-01

    Intense picosecond pulses cause accumulated optical damage in acetanilide crystals at low temperature. Catastrophic damage to the irradiated volume occurs after an incubation period where defects accumulate. The optical damage is monitored with subanosecond time resolution. The generation of defects is studied with damage-detected picosecond spectroscopy. The accumulation of defects is studied by time-resolved coherent Raman scattering, which is used to measure optical phonon scattering from the accumulating defects.

  16. Flexoelectric control of defect formation in ferroelectric epitaxial thin films.

    PubMed

    Lee, Daesu; Jeon, Byung Chul; Yoon, Aram; Shin, Yeong Jae; Lee, Myang Hwan; Song, Tae Kwon; Bu, Sang Don; Kim, Miyoung; Chung, Jin-Seok; Yoon, Jong-Gul; Noh, Tae Won

    2014-08-01

    Flexoelectric control of defect formation and associated electronic function is demonstrated in ferroelectric BiFeO3 thin films. An intriguing, so far never demonstrated, effect of internal electric field (Eint ) on defect formation is explored by a means of flexoelectricity. Our study provides novel insight into defect engineering, as well as allows a pathway to design defect configuration and associated electronic function. PMID:24847984

  17. Automated Diagnosis and Classification of Steam Generator Tube Defects

    SciTech Connect

    Dr. Gabe V. Garcia

    2004-10-01

    A major cause of failure in nuclear steam generators is tube degradation. Tube defects are divided into seven categories, one of which is intergranular attack/stress corrosion cracking (IGA/SCC). Defects of this type usually begin on the outer surface of the tubes and propagate both inward and laterally. In many cases these defects occur at or near the tube support plates. Several different methods exist for the nondestructive evaluation of nuclear steam generator tubes for defect characterization.

  18. Defect and disease detection in potato tubers

    NASA Astrophysics Data System (ADS)

    Muir, Andrew Y.; Ross, David W.; Dewar, Calum J.; Kennedy, Duncan D.

    1999-01-01

    To produce consistent products, graded to predetermined size and inspected for disease and defects such as bruising and common scab is important for the final quality presented to the consumer. A project funded by the British Potato Council, the Ministry of Agriculture Fisheries and Food, and RJ Herbert Engineering is aimed at developing spectrophotometric methods of disease detection previously investigated by SAC through to commercialization.

  19. Genetics and development of neural tube defects.

    PubMed

    Copp, Andrew J; Greene, Nicholas D E

    2010-01-01

    Congenital defects of neural tube closure (neural tube defects; NTDs) are among the commonest and most severe disorders of the fetus and newborn. Disturbance of any of the sequential events of embryonic neurulation produce NTDs, with the phenotype (eg anencephaly, spina bifida) varying depending on the region of neural tube that remains open. While mutation of > 200 genes is known to cause NTDs in mice, the pattern of occurrence in humans suggests a multifactorial polygenic or oligogenic aetiology. This emphasizes the importance of gene-gene and gene-environment interactions in the origins of these defects. A number of cell biological functions are essential for neural tube closure, with defects of the cytoskeleton, cell cycle and molecular regulation of cell viability prominent among the mouse NTD mutants. Many transcriptional regulators and proteins that affect chromatin structure are also required for neural tube closure, although the downstream molecular pathways regulated by these proteins is unknown. Some key signalling pathways for NTDs have been identified: over-activation of sonic hedgehog signalling and loss of function in the planar cell polarity (non-canonical Wnt) pathway are potent causes of NTD, with requirements also for retinoid and inositol signalling. Folic acid supplementation is an effective method for primary prevention of a proportion of NTDs in both humans and mice, although the embryonic mechanism of folate action remains unclear. Folic acid-resistant cases can be prevented by inositol supplementation in mice, raising the possibility that this could lead to an additional preventive strategy for human NTDs in future. PMID:19918803

  20. Positron studies of defected metals, metallic surfaces

    SciTech Connect

    Bansil, A.

    1991-01-01

    Specific problems proposed under this project included the treatment of electronic structure and momentum density in various disordered and defected systems. Since 1987, when the new high-temperature superconductors were discovered, the project focused extensively on questions concerning the electronic structure and Fermiology of high-[Tc] superconductors, in particular, (i) momentum density and positron experiments, (ii) angle-resolved photoemission intensities, (iii) effects of disorder and substitutions in the high-[Tc]'s.

  1. Ventricular Septal Defect from Takotsubo Syndrome

    PubMed Central

    Caplow, Julie; Quatromoni, Neha

    2016-01-01

    Takotsubo Syndrome is a transient condition characterized by left ventricular systolic dysfunction with apical akinesis/dyskinesis and ballooning. Although the prognosis with medical management is excellent in most cases, rare cases of serious complications can occur. We present here a case of a 71-year-old woman presenting with acute decompensated heart failure with initial findings consistent with a myocardial infarction, who was found instead to have an acute ventricular septal defect as a complication of Takotsubo Syndrome. PMID:27563471

  2. Micromagnetism and topological defects in magnetoelectric media

    NASA Astrophysics Data System (ADS)

    Pyatakov, A. P.; Sergeev, A. S.; Nikolaeva, E. P.; Kosykh, T. B.; Nikolaev, A. V.; Zvezdin, K. A.; Zvezdin, A. K.

    2015-10-01

    This paper briefly reviews research of the magnetoelectric materials and multiferroics as domain-structured media. The review is focused on magnetoelectric phenomena in epitaxial iron garnet films (electrically induced displacement and tilting of domain boundaries) as a striking example of magnetoelectricity in micromagnetism. The paper also considers the effect of an electric field on other topological defects in magnetically ordered media, including Bloch lines and Bloch points at domain boundaries, magnetic vortices, and skyrmions.

  3. Metastable light induced defects in pentacene

    SciTech Connect

    Liguori, R.; Aprano, S.; Rubino, A.

    2014-02-21

    In this study we analyzed one of the environmental factors that could affect organic materials. Pentacene thin film samples were fabricated and the degradation of their electrical characteristics was measured when the devices were exposed to ultraviolet light irradiation. The results have been reported in terms of a trap density model, which provides a description of the dynamics of light induced electrically active defects in an organic semiconductor.

  4. Defect Depth Measurement Using White Light Interferometry

    NASA Technical Reports Server (NTRS)

    Parker, Don; Starr, Stan

    2009-01-01

    The objectives of the White Light Interferometry project are the following: (1) Demonstrate a small hand-held instrument capable of performing inspections of identified defects on Orbiter outer pane window surfaces. (2) Build and field-test a prototype device using miniaturized optical components. (3) Modify the instrument based on field testing and begin the conversion of the unit to become a certified shop-aid.

  5. Defect Doping of InN

    SciTech Connect

    Jones, R.E.; van Genuchten, H.C.M.; Yu, K.M.; Walukiewicz, W.; Li, S.X.; A ger III, J.W.; Liliental-Weber, Z.; Haller, E.E.; Lu, H.; Schaff, W.J.

    2007-07-22

    InN films grown by molecular beam epitaxy have been subjected to 2 MeV He{sup +} irradiation followed by thermal annealing. Theoretical analysis of the electron mobilities shows that thermal annealing removes triply charged donor defects, creating films with electron mobilities approaching those predicted for uncompensated, singly charged donors. Optimum thermal annealing of irradiated InN can be used to produce samples with electron mobilities higher than those of as grown films.

  6. Quantum conductance of carbon nanotubes with defects

    SciTech Connect

    Chico, L.; Benedict, L.X.; Louie, S.G.; Cohen, M.L. |

    1996-07-01

    We study the conductance of metallic carbon nanotubes with vacancies and pentagon-heptagon pair defects within the Landauer formalism. Using a tight-binding model and a Green{close_quote}s function technique to calculate the scattering matrix, we examine the one-dimensional to two-dimensional crossover in these systems and show the existence of metallic tube junctions in which the conductance is suppressed for symmetry reasons. {copyright} {ital 1996 The American Physical Society.}

  7. Octagonal Defects at Carbon Nanotube Junctions

    PubMed Central

    Jaskólski, W.; Pelc, M.; Chico, Leonor; Ayuela, A.

    2013-01-01

    We investigate knee-shaped junctions of semiconductor zigzag carbon nanotubes. Two dissimilar octagons appear at such junctions; one of them can reconstruct into a pair of pentagons. The junction with two octagons presents two degenerate localized states at Fermi energy (EF). The reconstructed junction has only one state near EF, indicating that these localized states are related to the octagonal defects. The inclusion of Coulomb interaction splits the localized states in the junction with two octagons, yielding an antiferromagnetic system. PMID:24089604

  8. Quantifying defects in zeolites and zeolite membranes

    NASA Astrophysics Data System (ADS)

    Hammond, Karl Daniel

    Zeolites are crystalline aluminosilicates that are frequently used as catalysts to transform chemical feedstocks into more useful materials in a size- or shape-selective fashion; they are one of the earliest forms of nanotechnology. Zeolites can also be used, especially in the form of zeolite membranes (layers of zeolite on a support), to separate mixtures based on the size of the molecules. Recent advances have also created the possibility of using zeolites as alkaline catalysts, in addition to their traditional applications as acid catalysts and catalytic supports. Transport and catalysis in zeolites are greatly affected by physical and chemical defects. Such defects can be undesirable (in the case of zeolite membranes), or desirable (in the case of nitrogen-doped alkaline zeolites). Studying zeolites at the relevant length scales requires indirect experimental methods such as vapor adsorption or atomic-scale modeling such as electronic structure calculations. This dissertation explores both experimental and theoretical characterization of zeolites and zeolite membranes. Physical defects, important in membrane permeation, are studied using physical adsorption experiments and models of membrane transport. The results indicate that zeolite membranes can be modeled as a zeolite powder on top of a support---a "supported powder," so to speak---for the purposes of adsorption. Mesoporosity that might be expected based on permeation and confocal microscopy measurements is not observed. Chemical defects---substitutions of nitrogen for oxygen---are studied using quantum mechanical models that predict spectroscopic properties. These models provide a method for simulating the 29Si NMR spectra of nitrogendefected zeolites. They also demonstrate that nitrogen substitutes into the zeolite framework (not just on the surface) under the proper reaction conditions. The results of these studies will be valuable to experimentalists and theorists alike in our efforts to understand the

  9. Defects of the Glycinergic Synapse in Zebrafish

    PubMed Central

    Ogino, Kazutoyo; Hirata, Hiromi

    2016-01-01

    Glycine mediates fast inhibitory synaptic transmission. Physiological importance of the glycinergic synapse is well established in the brainstem and the spinal cord. In humans, the loss of glycinergic function in the spinal cord and brainstem leads to hyperekplexia, which is characterized by an excess startle reflex to sudden acoustic or tactile stimulation. In addition, glycinergic synapses in this region are also involved in the regulation of respiration and locomotion, and in the nociceptive processing. The importance of the glycinergic synapse is conserved across vertebrate species. A teleost fish, the zebrafish, offers several advantages as a vertebrate model for research of glycinergic synapse. Mutagenesis screens in zebrafish have isolated two motor defective mutants that have pathogenic mutations in glycinergic synaptic transmission: bandoneon (beo) and shocked (sho). Beo mutants have a loss-of-function mutation of glycine receptor (GlyR) β-subunit b, alternatively, sho mutant is a glycinergic transporter 1 (GlyT1) defective mutant. These mutants are useful animal models for understanding of glycinergic synaptic transmission and for identification of novel therapeutic agents for human diseases arising from defect in glycinergic transmission, such as hyperekplexia or glycine encephalopathy. Recent advances in techniques for genome editing and for imaging and manipulating of a molecule or a physiological process make zebrafish more attractive model. In this review, we describe the glycinergic defective zebrafish mutants and the technical advances in both forward and reverse genetic approaches as well as in vivo visualization and manipulation approaches for the study of the glycinergic synapse in zebrafish. PMID:27445686

  10. Vision Algorithms Catch Defects in Screen Displays

    NASA Technical Reports Server (NTRS)

    2014-01-01

    Andrew Watson, a senior scientist at Ames Research Center, developed a tool called the Spatial Standard Observer (SSO), which models human vision for use in robotic applications. Redmond, Washington-based Radiant Zemax LLC licensed the technology from NASA and combined it with its imaging colorimeter system, creating a powerful tool that high-volume manufacturers of flat-panel displays use to catch defects in screens.

  11. Perfluorooctanoate Exposure and Major Birth Defects

    PubMed Central

    Stein, Cheryl R.; Savitz, David A.; Elston, Beth; Thorpe, Phoebe G.; Gilboa, Suzanne M.

    2014-01-01

    Perfluorooctanoate (PFOA) is detectable in umbilical cord blood and amniotic fluid. Some toxicological findings suggest that perfluoroalkyl substances may be teratogenic. Using data from the C8 Health Project, a 2005 – 2006 survey in a Mid-Ohio Valley community exposed to PFOA through contaminated drinking water, we examined the association between estimated prenatal PFOA concentration and maternally reported birth defects (n=325) among 10,262 live singleton or multiple births from 1990 – 2006. Logistic regression models accounted for siblings using generalized estimating equations. There was generally no association between estimated PFOA concentration and birth defects, with the possible exception of brain defects, where the odds ratio adjusted for year of conception was 2.6 (95% confidence interval 1.3 – 5.1) for an increase in estimated PFOA exposure from the 25th to 75th percentile. This estimate, however, was based on 13 cases and may represent a chance finding. Further investigation of this potential association may be warranted. PMID:24803403

  12. Simulating Topological Defects in Twisted Fiber Bundles

    NASA Astrophysics Data System (ADS)

    Bruss, Isaac R.; Grason, Gregory M.

    2012-02-01

    Twisted bundles are a common motif found in naturally occurring structures of self-assembled fibers, such as collagen and fibrin. By understanding the general principles governing such organizations, new synthetic materials--from the nano to the macroscale--may also be realized. Recently, continuum elasticity theory has been applied to describe generic twisted fiber bundles. This has revealed a relation between a bundle's twist and the presence of topological defects in the cross-sectional packing of the fibers. Here we employ numerical simulations to examine this interdependence. We model a bundle's cross-section as beads confined to a plane. The interactions between beads is governed by a modified Lennard-Jones potential that accounts for the effects of twist. We observe configurations that range from perfect hexagonal packing for cases of no twist, to defect populated structures above a critical amount of twist. For small bundles of less than ˜100 beads, there exists a discrete spectrum of energy ground states corresponding to integer numbers of five-fold disclinations. For larger bundles, we hope to uncover what types of defect arrangements effectively screen the stresses caused by twist, and compare these to current predictions of the internal organization of collagen fibrils.

  13. Critical phenomena of a single defect

    NASA Astrophysics Data System (ADS)

    Wu, Xintian; Zhang, Yangyang

    2015-09-01

    We consider the critical system with a point defect and study the variation of thermodynamic quantities, which are the differences between those with and without the defect. Within renormalization group theory, we show generally that the critical exponent of the internal energy variation is the specific heat exponent of a pure system, and the critical exponent of the heat capacity variation is that for the temperature derivative of specific heat of a pure system. This conclusion is valid for the isotropic systems with a short-range interaction. As an example we solve the two-dimensional Ising model with a point defect numerically. The variations of the free energy, internal energy, and specific heat are calculated with the bond propagation algorithm. At the critical point, the internal energy variation diverges with the lattice size logarithmically and the heat capacity variation diverges with size linearly. Near the critical point, the internal energy variation behaves as ln|t | and the heat capacity variation behaves as |t| -1, where t is the reduced temperature.

  14. Multispectral inspection station detects defects on apples

    NASA Astrophysics Data System (ADS)

    Throop, James A.; Aneshansley, Daniel J.; Anger, Bill

    2000-12-01

    The performance of a multi-spectral apple inspection station capable of orienting some cultivars, conveying, and presenting apples to a camera at five apples per second is described. Apples are pre-sized and hand placed on the conveying devices to rotate about an axis passing through both the stem and calyx of each apple. An image of each apple is captured at four different wavelengths through a common aperture. Special optics and filters allow simultaneous image capture of apple reflectance for wavelength bands of 540 nm, 650 nm, 750 nm, and 950 nm, each with a bandwidth of approximately 60 nm. As each apple is conveyed laterally and rotated through the camera's field of view, 6 regions of interest representing most of the apple's surface at each wavelength band are captured. The images are processed to segment each defect from the surrounding undamaged tissue and the area of each defect is recorded. Typical defects such as new bruises, bruises on stored apples, scab, sooty blotch, corking, rot, russet, and insect damage are detected. Data is shown quantifying the ability of the inspection station to sort damaged apples into appropriate grades for correct pricing in the processing industry.

  15. Ripplocations: A Novel Defect in Layered Materials

    NASA Astrophysics Data System (ADS)

    Gruber, Jacob; Lang, Andrew; Griggs, Justin; Tucker, Garritt; Barsoum, Michel

    Recently, a new defect, the ripplocation, the mechanical buckling of a single atomic layer, was proposed to explain the behavior of two dimensional materials. Leveraging atomistic simulations, this concept is extended to bulk layered materials. Unlike dislocations, ripplocations do not possess a Burgers vector and do not have polarity. In graphite, ripplocations are attracted both to vacancies, where they can annihilate, and other ripplocations, forming larger complexes and eventually kink boundaries. While some ripplocation behavior can be described by dislocation complexes, the failure of these models to explain core interactions suggests that ripplocations are a fundamentally new class of defect. Furthermore, TEM examination of nanoindented Ti3SiC2, where dislocation theory does not provide a complete description of behavior, reveals the presence of defects with no Burgers vector and with rotation and strain fields similar to those predicted in simulation, suggesting the presences of buckled basal planes. Ripplocations have profound implications for the deformation of plastically anisotropic solids, including graphite, layered silicates and the MAX phases.

  16. Dark matter from decaying topological defects

    SciTech Connect

    Hindmarsh, Mark; Kirk, Russell; West, Stephen M. E-mail: russell.kirk.2008@live.rhul.ac.uk

    2014-03-01

    We study dark matter production by decaying topological defects, in particular cosmic strings. In topological defect or ''top-down'' (TD) scenarios, the dark matter injection rate varies as a power law with time with exponent p−4. We find a formula in closed form for the yield for all p < 3/2, which accurately reproduces the solution of the Boltzmann equation. We investigate two scenarios (p = 1, p = 7/6) motivated by cosmic strings which decay into TeV-scale states with a high branching fraction into dark matter particles. For dark matter models annihilating either by s-wave or p-wave, we find the regions of parameter space where the TD model can account for the dark matter relic density as measured by Planck. We find that topological defects can be the principal source of dark matter, even when the standard freeze-out calculation under-predicts the relic density and hence can lead to potentially large ''boost factor'' enhancements in the dark matter annihilation rate. We examine dark matter model-independent limits on this scenario arising from unitarity and discuss example model-dependent limits coming from indirect dark matter search experiments. In the four cases studied, the upper bound on Gμ for strings with an appreciable channel into TeV-scale states is significantly more stringent than the current Cosmic Microwave Background limits.

  17. Defect-Free Carbon Nanotube Coils.

    PubMed

    Shadmi, Nitzan; Kremen, Anna; Frenkel, Yiftach; Lapin, Zachary J; Machado, Leonardo D; Legoas, Sergio B; Bitton, Ora; Rechav, Katya; Popovitz-Biro, Ronit; Galvão, Douglas S; Jorio, Ado; Novotny, Lukas; Kalisky, Beena; Joselevich, Ernesto

    2016-04-13

    Carbon nanotubes are promising building blocks for various nanoelectronic components. A highly desirable geometry for such applications is a coil. However, coiled nanotube structures reported so far were inherently defective or had no free ends accessible for contacting. Here we demonstrate the spontaneous self-coiling of single-wall carbon nanotubes into defect-free coils of up to more than 70 turns with identical diameter and chirality, and free ends. We characterize the structure, formation mechanism, and electrical properties of these coils by different microscopies, molecular dynamics simulations, Raman spectroscopy, and electrical and magnetic measurements. The coils are highly conductive, as expected for defect-free carbon nanotubes, but adjacent nanotube segments in the coil are more highly coupled than in regular bundles of single-wall carbon nanotubes, owing to their perfect crystal momentum matching, which enables tunneling between the turns. Although this behavior does not yet enable the performance of these nanotube coils as inductive devices, it does point a clear path for their realization. Hence, this study represents a major step toward the production of many different nanotube coil devices, including inductors, electromagnets, transformers, and dynamos. PMID:26708150

  18. Reconstructive Surgery of Auricular Defects: An Overview

    PubMed Central

    Ebrahimi, Ali; Kazemi, Alireza; Rasouli, Hamid Reza; Kazemi, Maryam; Kalantar Motamedi, Mohammad Hosein

    2015-01-01

    Context: Despite the ongoing advances in surgical procedures and promising progress in bioengineering techniques, auricular reconstruction remains a significant challenge in plastic surgery. There are different causes for acquired auricular defects, including trauma, tumor ablation and burns. The management options for upper, middle and lower third auricular defects are briefly reviewed in the current paper. Evidence Acquisition: Original research papers investigating the plastic surgeons, otolaryngologists and maxillofacial surgeons in approaching the complicated issue of auricular reconstruction published from January 1995 to December 2014 were aggregated and used in the current study. Results: Utilizing autologous stem cell populations to treat craniofacial defects is a promising field of ongoing investigations. Studies show that cartilage stem/progenitor cells (CSPCs) are highly chondrogenic and can produce elastic reconstructive material with long-term tissue restoration. Conclusions: Auricular reconstruction surgery is a challenging plastic procedure that requires great expertise and expert knowledge of the various techniques available. Novel techniques in the fields of reconstructive bioengineering and regenerative medicine are promising but further research is required before widespread clinical application. PMID:26839867

  19. Heterogeneous Catalysis on Defect-Engineered Graphene

    NASA Astrophysics Data System (ADS)

    El-Shall, M.

    2013-03-01

    Graphene has attracted great interest for a fundamental understanding of its unique structural and electronic properties and also for important potential applications in nanoelectronics and devices. The combination of thermal, chemical and mechanical stability with the high surface area offers many interesting applications in a wide range of fields including heterogeneous catalysis where metallic and bimetallic nanoparticle catalysts can be efficiently dispersed on the graphene sheets. We have developed facile and scalable chemical and laser reduction methods for the synthesis of defect-engineered graphene, as well as metal and semiconductor nanoparticles dispersed on graphene. We recently discovered a remarkable catalytic activity of metal nanoparticles supported on defect-engineered graphene in a variety of chemical transformation including carbon-carbon cross coupling reactions and Fischer-Tropsch Synthesis of long chain liquid hydrocarbons. The results demonstrate the role of the defect sites on the graphene surface in providing favorable nucleation sites for the selective deposition of the metal nanoparticles and as a result, play a major role in imparting exceptional catalytic properties. We thank the National Science Foundation CHE-0911146 Grant for the support of this work.

  20. Defect-free atom arrays on demand

    NASA Astrophysics Data System (ADS)

    Levine, Harry; Bernien, Hannes; Keesling, Alex; Anschuetz, Eric; Senko, Crystal; Vuletic, Vladan; Greiner, Markus; Endres, Manuel; Lukin, Mikhail

    2016-05-01

    Arrays of neutral, trapped atoms have proven to be an extraordinary platform for studying quantum many-body physics and implementing quantum information protocols. Conventional approaches to generate such arrays rely on loading atoms into optical lattices and require elaborate experimental control. An alternative, simpler approach is to load atoms into individual optical tweezers. However, the probabilistic nature of the loading process limits the size of the arrays to small numbers of atoms. Here we present a new method for assembling defect-free arrays of large numbers of atoms. Our technique makes use of an array of tightly focused optical tweezers generated by an acousto-optic deflector. The positions of the traps can be dynamically reconfigured on a sub-millisecond timescale. With single-site resolved fluorescence imaging, we can identify defects in the atom array caused by the probabilistic loading process and rearrange the trap positions in response. This will enable us to generate defect-free atom arrays on demand. We discuss our latest results towards reaching this goal along with schemes to implement long-range interactions between atoms in the array. Now at Caltech.

  1. Defect-free atom arrays on demand

    NASA Astrophysics Data System (ADS)

    Bernien, Hannes; Keesling, Alexander; Levine, Harry; Anschuetz, Eric; Senko, Crystal; Vuletic, Vladan; Greiner, Markus; Endres, Manuel; Lukin, Mikhail D.

    2016-05-01

    Arrays of neutral, trapped atoms have proven to be an extraordinary platform for studying quantum many-body physics and implementing quantum information protocols. Conventional approaches to generate such arrays rely on loading atoms into optical lattices and require elaborate experimental control. An alternative, simpler approach is to load atoms into individual optical tweezers. However, the probabilistic nature of the loading process limits the size of the arrays to small numbers of atoms. Here we present a new method for assembling defect-free arrays of large numbers of atoms. Our technique makes use of an array of tightly focused optical tweezers generated by an acousto-optic deflector. The positions of the traps can be dynamically reconfigured on a sub-millisecond timescale. With single-site resolved fluorescence imaging, we can identify defects in the atom array caused by the probabilistic loading process and rearrange the trap positions in response. This will enable us to generate defect-free atom arrays on demand. We discuss our latest results towards reaching this goal along with schemes to implement long-range interactions between atoms in the array.

  2. Isospin of topological defects in Dirac systems

    NASA Astrophysics Data System (ADS)

    Herbut, Igor F.

    2012-02-01

    We study the Dirac quasiparticles in d-dimensional lattice systems of electrons in the presence of domain walls (d=1), vortices (d=2), or hedgehogs (d=3) of superconducting and/or insulating, order parameters, which appear as mass terms in the Dirac equation. Such topological defects have been known to carry nontrivial quantum numbers, such as charge and spin. Here we discuss their additional internal degree of freedom: irrespective of the dimensionality of space and the nature of orders that support the defect, an extra mass order parameter is found to emerge in their core. Six linearly independent local orders, which close two mutually commuting three-dimensional Clifford algebras, are proven to be in general possible. We show how the particle-hole symmetry restricts the defects to always carry the quantum numbers of a single effective isospin 1/2, quite independently of the values of their electric charge or true spin. Examples of this new degree of freedom in graphene and on surfaces of topological insulators are discussed.

  3. Current Strategies in Reconstruction of Maxillectomy Defects

    PubMed Central

    Andrades, Patricio; Militsakh, Oleg; Hanasono, Matthew M.; Rieger, Jana; Rosenthal, Eben L.

    2014-01-01

    Objective To outline a contemporary review of defect classification and reconstructive options. Design Review article. Setting Tertiary care referral centers. Results Although prosthetic rehabilitation remains the standard of care in many institutions, the discomfort of wearing, removing, and cleaning a prosthesis; the inability to retain a prosthesis in large defects; and the frequent need for readjustments often limit the value of this cost-effective and successful method of restoring speech and mastication. However, flap reconstruction offers an option for many, although there is no agreement as to which techniques should be used for optimal reconstruction. Flap reconstruction also involves a longer recovery time with increased risk of surgical complications, has higher costs associated with the procedure, and requires access to a highly experienced surgeon. Conclusion The surgeon and reconstructive team must make individualized decisions based on the extent of the maxillectomy defect (eg, the resection of the infraorbital rim, the extent of palate excision, skin compromise) and the need for radiation therapy. PMID:21844415

  4. Defect printability in CPL mask technology

    NASA Astrophysics Data System (ADS)

    Kuijten, Jan-Pieter; Verhappen, Arjan; Pijnenburg, Wil; Conley, Will; Litt, Lloyd C.; Wu, Wei; Montgomery, Patrick; Roman, Bernard J.; Kasprowicz, Bryan S.; Progler, Christopher J.; Socha, Robert J.; Van Den Broeke, Douglas J.; Schaefer, Erika; Cook, Pat

    2004-05-01

    Each generation of semiconductor device technology drive new and interesting resolution enhancement technology (RET"s). The race to smaller and smaller geometry"s has forced device manufacturers to k1"s approaching 0.40. The authors have been investigating the use of Chromeless phase-shifting masks (CPL) exposed with ArF, high numerical aperture (NA), and off-axis illumination (OAI) has been shown to produce production worthy sub-100nm resist patterns with acceptable overlapped process window across feature pitch. These new reticle technologies have many issues that are similar to simple binary masks. The authors have investigated the printability of defects in CPL mask technology. Programmed defects of various sizes and types have been simulated and printed for sub 100nm imaging. High resolution scanning electron microscopy has been used to characterize these defects and develop an understanding of size and type that prints. In this paper the authors will focus on image line end shortening and the impact of through dose and focus performance for very high NA ArF imaging. The authors have built a number of test structures that require superior 2D control for SRAM gate structures. Various types of line ends have been evaluated for either straight CPL mask or hybrid type builds.

  5. 21 CFR 1003.2 - Defect in an electronic product.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Defect in an electronic product. 1003.2 Section 1003.2 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) RADIOLOGICAL HEALTH NOTIFICATION OF DEFECTS OR FAILURE TO COMPLY General Provisions § 1003.2 Defect in...

  6. 21 CFR 1003.2 - Defect in an electronic product.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Defect in an electronic product. 1003.2 Section 1003.2 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) RADIOLOGICAL HEALTH NOTIFICATION OF DEFECTS OR FAILURE TO COMPLY General Provisions § 1003.2 Defect in...

  7. 21 CFR 1003.2 - Defect in an electronic product.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Defect in an electronic product. 1003.2 Section 1003.2 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) RADIOLOGICAL HEALTH NOTIFICATION OF DEFECTS OR FAILURE TO COMPLY General Provisions § 1003.2 Defect in an electronic product. For the purpose...

  8. 38 CFR 4.9 - Congenital or developmental defects.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Congenital or developmental defects. 4.9 Section 4.9 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS SCHEDULE FOR RATING DISABILITIES General Policy in Rating § 4.9 Congenital or developmental defects. Mere congenital or developmental defects,...

  9. Defect-induced semiconductor to metal transition in graphene monoxide.

    PubMed

    Woo, Jungwook; Yun, Kyung-Han; Cho, Sung Beom; Chung, Yong-Chae

    2014-07-14

    This study investigates the influence of point defects on the geometric and electronic structure of graphene monoxide (GMO) via density functional theory calculations. In aspects of defect formation energy, GMOs with oxygen vacancies and bridge interstitial defects are more likely to form when compared to GMOs with defects such as carbon vacancies and hollow interstitial defects. It was also found that the oxygen vacancy or the hollow interstitial defect induces local tensile strain around the defective site and this strain increases the band gap energy of the defective GMO. In addition, the band gaps of GMO with carbon vacancies or bridge interstitial defects decreased mainly due to the dangling bonds, not due to the strain effect. It is noted that the dangling bond derived from the defects forms the defect-level in the band gap of GMO. The semiconductor to metal transition by the band gap change (0-0.7 eV) implies the possibility for band gap engineering of GMO by vacancies and interstitial defects. PMID:24886723

  10. Toward defect-free fabrication of extreme ultraviolet photomasks

    NASA Astrophysics Data System (ADS)

    Qi, Zhengqing John; Rankin, Jed H.; Lawliss, Mark; Badger, Karen D.; Turley, Christina

    2016-04-01

    Defect-free fabrication of extreme ultraviolet (EUV) masks relies on the appropriate detection of native defects and subsequent strategies for their elimination. Commercial unavailability of actinic mask-blank inspection systems motivates the identification of an optical inspection methodology most suitable for finding relevant EUV blank defects. Studies showed that 193-nm wavelength inspection found the greatest number of printable defects as compared with rival higher-wavelength systems, establishing deep ultraviolet inspections as the blank defectivity baseline for subsequent mitigation strategies. Next, defect avoidance via pattern shifting was explored using representative 7-nm node metal/contact layer designs and 193-nm mask-blank inspection results. It was found that a significant percentage of native defects could be avoided only when the design was limited to active patterns (i.e., layouts without dummy fill). Total pattern-defect overlap remained ≤5 when metal layer blanks were chosen from the top 35% least defective substrates, while the majority of blanks remained suitable for contacts layers due to a lower active pattern density. Finally, nanomachining was used to address remaining native/multilayer defects. Native catastrophic defects were shown to recover 40% to 70% of target critical dimension after nanomachining, demonstrating the enormous potential for compensating multilayer defects.

  11. Theoretical studies of defects in binary and ternary oxides

    SciTech Connect

    Ching, W.Y.; Ellis, D.E.; Lam, D.J.

    1986-01-01

    This paper presents some preliminary results of electronic structure of substitutional defects and vacancy in binary and ternary cubic zirconium oxides obtained by the embedded molecular-cluster model calculation. The importance of electronic charge redistribution in the solids where the defect is introduced into the perfect lattice is highlighted and the effect of electron polarization of the surrounding ions of the defect discussed.

  12. 7 CFR 51.2340 - Classification of defects.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Classification of defects. 51.2340 Section 51.2340... STANDARDS) United States Standards for Grades of Kiwifruit § 51.2340 Classification of defects. Defects... area of a circle 3/8 inch (9.5 mm) in diameter, or lesser bruises aggregating an area of a circle...

  13. 7 CFR 51.494c - Condition defects.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Condition defects. 51.494c Section 51.494c Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Standards for Grades of Cantaloups 1 Definitions § 51.494c Condition defects. Condition defects...

  14. Haemolysis after Amplatzer device closure of ventricular septal defect

    PubMed Central

    Mulvaney, S; Grech, V

    2007-01-01

    Over the last few years, a vast variety of devices have been developed to close various septal defects through the transcatheter route. Haemolysis has been documented after Amplatzer device closure of patent ductus arteriousus, atrial septal defect, and ventricular septal defect. We report one patient with self-limiting haemolysis after implantation of an Amplatzer perimembranous VSD device. PMID:22368673

  15. Defect stability in thorium monocarbide: An ab initio study

    NASA Astrophysics Data System (ADS)

    Wang, Chang-Ying; Han, Han; Shao, Kuan; Cheng, Cheng; Huai, Ping

    2015-09-01

    The elastic properties and point defects of thorium monocarbide (ThC) have been studied by means of density functional theory based on the projector-augmented-wave method. The calculated electronic and elastic properties of ThC are in good agreement with experimental data and previous theoretical results. Five types of point defects have been considered in our study, including the vacancy defect, interstitial defect, antisite defect, schottky defect, and composition-conserving defect. Among these defects, the carbon vacancy defect has the lowest formation energy of 0.29 eV. The second most stable defect (0.49 eV) is one of composition-conserving defects in which one carbon is removed to another carbon site forming a C2 dimer. In addition, we also discuss several kinds of carbon interstitial defects, and predict that the carbon trimer configuration may be a transition state for a carbon dimer diffusion in ThC. Project supported by the International S&T Cooperation Program of China (Grant No. 2014DFG60230), the National Natural Science Foundation of China (Grant No. 91326105), the National Basic Research Program of China (Grant No. 2010CB934504), and the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA02040104).

  16. 7 CFR 51.2280 - Tolerances for grade defects.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Tolerances for grade defects. 51.2280 Section 51.2280... § 51.2280 Tolerances for grade defects. (a) All percentages shall be claculated on the basis of weight... (included in 1 percent very serious damage). U.S. Commercial 8 4 (included in 8 percent total defects)...

  17. Maternal intake of vitamin E and birth defects, National Birth Defects Prevention Study, 1997–2005

    PubMed Central

    Gilboa, Suzanne M.; Lee, Kyung A.; Cogswell, Mary E.; Traven, Flavia K.; Botto, Lorenzo D.; Riehle-Colarusso, Tiffany; Correa, Adolfo; Boyle, Coleen A.

    2015-01-01

    Background In a recent study, high maternal periconceptional intake of vitamin E was found to be associated with risk of congenital heart defects (CHDs). To explore this association further, we investigated the association between total daily vitamin E intake and selected birth defects. Methods We analyzed data from 4,525 controls and 8,665 cases from the 1997–2005 National Birth Defects Prevention Study. We categorized estimated periconceptional energy-adjusted total daily vitamin E intake from diet and supplements into quartiles (referent, lowest quartile). Associations between quartiles of energy-adjusted vitamin E intake and selected birth defects were adjusted for demographic, lifestyle, and nutritional factors. Results We observed a statistically significant association with the third quartile of vitamin E intake (OR 1.17; 95% CI 1.01 – 1.35) and all CHDs combined. Among CHD sub-types, we observed associations with left ventricular outflow tract obstruction defects, and its sub-type, coarctation of the aorta and the third quartile of vitamin E intake. Among defects other than CHDs, we observed associations between anorectal atresia and the third quartile of vitamin E intake (OR 1.66; 95% CI 1.01 – 2.72) and hypospadias and the fourth quartile of vitamin E intake (OR 1.42; 95% CI 1.09 – 1.87). Conclusions Selected quartiles of energy-adjusted estimated total daily vitamin E intake were associated with selected birth defects. However, because these few associations did not exhibit exposure-response patterns consistent with increasing risk associated with increasing intake of vitamin E, further studies are warranted to corroborate our findings. PMID:24740457

  18. EUV mask and wafer defectivity: strategy and evaluation for full die defect inspection

    NASA Astrophysics Data System (ADS)

    Bonam, Ravi; Tien, Hung-Yu; Chou, Acer; Meli, Luciana; Halle, Scott; Wu, Ivy; Huang, Xiaoxia; Lei, Chris; Kuan, Chiyan; Wang, Fei; Corliss, Daniel; Fang, Wei; Jau, Jack; Qi, Zhengqing John; Badger, Karen; Turley, Christina; Rankin, Jed

    2016-03-01

    Over the past few years numerous advancements in EUV Lithography have proven its feasibility of insertion into High Volume Manufacturing (HVM).1, 2 A lot of progress is made in the area of pellicle development but a commercially solution with related infrastructure is currently unavailable.3, 4 Due to current mask structure and unavailability of a pellicle, a comprehensive strategy to qualify (native defects) and monitor (adder defects) defectivity on mask and wafer is required for implementing EUV Lithography in High Volume Manufacturing. In this work, we assess multiple strategies for mask and wafer defect inspection including a two-fold solution to leverage resolution of e-beam inspection along with throughput of optical inspection are evaluated. Defect capture rates for inspections based on full-die, critical areas based on priority and hotspots based on design and prior inspection data are evaluated. Each strategy has merits and de-merits, particularly related to throughput, effective die coverage and computational overhead. A production ready EUV Exposure tool was utilized to perform exposures at the IBM EUV Center of Excellence in Albany, NY for EUV Lithography Development along with a fully automated line of EUV Mask Infrastructure tools. We will present strategies considered in this study and discuss respective results. The results from the study indicate very low transfer rate of defect detection events from optical mask inspection. They also suggest a hybrid strategy of utilizing both optical and e-beam inspection can provide a comprehensive defect detection which can be employed in High Volume Manufacturing.

  19. A population-based study of birth defects in Malaysia.

    PubMed

    Thong, M K; Ho, J J; Khatijah, N N

    2005-01-01

    Birth defects are one of the leading causes of paediatric disability and mortality in developed and developing countries. Data on birth defects from population-based studies originating from developing countries are lacking. One of the objectives of this study was to determine the epidemiology of major birth defects in births during the perinatal period in Kinta district, Perak, Malaysia over a 14-month period, using a population-based birth defect register. There were 253 babies with major birth defects in 17,720 births, giving an incidence of 14.3/1000 births, a birth prevalence of 1 in 70. There were 80 babies with multiple birth defects and 173 with isolated birth defects. The exact syndromic diagnosis of the babies with multiple birth defects could not be identified in 18 (22.5%) babies. The main organ systems involved in the isolated birth defects were cardiovascular (13.8%), cleft lip and palate (11.9%), clubfeet (9.1%), central nervous system (CNS) (including neural tube defects) (7.9%), musculoskeletal (5.5%) and gastrointestinal systems (4.7%), and hydrops fetalis (4.3%). The babies with major birth defects were associated with lower birth weights, premature deliveries, higher Caesarean section rates, prolonged hospitalization and increased specialist care. Among the cohort of babies with major birth defects, the mortality rate was 25.2% during the perinatal period. Mothers with affected babies were associated with advanced maternal age, birth defects themselves or their relatives but not in their other offspring, and significantly higher rates of previous abortions. The consanguinity rate of 2.4% was twice that of the control population. It is concluded that a birth defects register is needed to monitor these developments and future interventional trials are needed to reduce birth defects in Malaysia. PMID:16096215

  20. 77 FR 27790 - Mortgagee's Certificate of Fees and Escrow and Surety Bond Against Defects Due to Defective...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-11

    ... URBAN DEVELOPMENT Mortgagee's Certificate of Fees and Escrow and Surety Bond Against Defects Due to... and Escrow and Surety Bond Against Defects Due to Defective Material and/or Faulty Workmanship. OMB... the required escrows will be collected. HUD determines the reasonableness of the fees and uses...

  1. A fake defect phenomenon in defect detection of thermographic NDT: a three-dimensional numerical analysis

    NASA Astrophysics Data System (ADS)

    Fan, Chunli; Wang, Hailiang; Zhang, Lin; Yang, Li; Sun, Fengrui

    2015-10-01

    As we all know, the temperature distributions reflected in the thermal images are the basis for detecting the information of subsurface defect in thermographic NDT. In the actual work of thermographic nondestructive inspection of the inner surface geometry of a plate-shaped structure, the cave defect in the inner heated surface usually results in a temperature rise of the outer inspection surface. However, on some specific conditions, an extension on the inner surface will also result in the same temperature rise of the inspection surface. Because the extension has no negative effect on the reliability of the plate or this extension is an originally designed functional structure, we may call this extension of the inner surface "fake defect". In this paper, we will take a three-dimensional plate with a cylindrical extension as an example to discuss how this fake-defect phenomenon forms and when this phenomenon appears. This study is of meaning to both the inspection and quantitative identification of the inner-surface defect based on infrared thermographic temperature measurements of the outer plate surface.

  2. The influence of defects on the effective Young's modulus of a defective solid

    NASA Astrophysics Data System (ADS)

    Shen, Wei; Fan, Qun-Bo; Wang, Fu-Chi; Ma, Zhuang

    2013-04-01

    It is difficult to establish structure-property relationships in a defective solid because of its inhomogeneous-geometry microstructure caused by defects. In the present research, the effects of pores and cracks on the Young's modulus of a defective solid are studied. Based on the law of the conservation of energy, mathematical formulations are proposed to indicate how the shape, size, and distribution of defects affect the effective Young's modulus. In this approach, detailed equations are illustrated to represent the shape and size of defects on the effective Young's modulus. Different from the results obtained from the traditional empirical analyses, mixture law or statistical method, for the first time, our results from the finite element method (FEM) and strict analytical calculation show that the influence of pore radius and crack length on the effective Young's modulus can be quantified. It is found that the longest crack in a typical microstructure of ceramic coating dominates the contribution of the effective Young's modulus in the vertical direction of the crack.

  3. Defects in Silicene: Vacancy Clusters, Extended Line Defects, and Di-adatoms

    PubMed Central

    Li, Shuang; Wu, Yifeng; Tu, Yi; Wang, Yonghui; Jiang, Tong; Liu, Wei; Zhao, Yonghao

    2015-01-01

    Defects are almost inevitable during the fabrication process, and their existence strongly affects thermodynamic and (opto)electronic properties of two-dimensional materials. Very recent experiments have provided clear evidence for the presence of larger multi-vacancies in silicene, but their structure, stability, and formation mechanism remain largely unexplored. Here, we present a detailed theoretical study of silicene monolayer containing three types of defects: vacancy clusters, extended line defects (ELDs), and di-adatoms. First-principles calculations, along with ab initio molecular dynamics simulations, revealed the coalescence tendency of small defects and formation of highly stable vacancy clusters. The 5|8|5 ELD – the most favorable extended defect in both graphene and silicene sheets – is found to be easier to form in the latter case due to the mixed sp2/sp3 hybridization of silicon. In addition, hybrid functional calculations that contain part of the Hatree-Fock exchange energy demonstrated that the introduction of single and double silicon adatoms significantly enhances the stability of the system, and provides an effective approach on tuning the magnetic moment and band gap of silicene. PMID:25619941

  4. A single-molecule approach to ZnO defect studies: Single photons and single defects

    SciTech Connect

    Jungwirth, N. R.; Pai, Y. Y.; Chang, H. S.; MacQuarrie, E. R.; Nguyen, K. X.; Fuchs, G. D.

    2014-07-28

    Investigations that probe defects one at a time offer a unique opportunity to observe properties and dynamics that are washed out of ensemble measurements. Here, we present confocal fluorescence measurements of individual defects in ZnO nanoparticles and sputtered films that are excited with sub-bandgap energy light. Photon correlation measurements yield both antibunching and bunching, indicative of single-photon emission from isolated defects that possess a metastable shelving state. The single-photon emission is in the range of ∼560–720 nm and typically exhibits two broad spectral peaks separated by ∼150 meV. The excited state lifetimes range from 1 to 13 ns, consistent with the finite-size and surface effects of nanoparticles and small grains. We also observe discrete jumps in the fluorescence intensity between a bright state and a dark state. The dwell times in each state are exponentially distributed and the average dwell time in the bright (dark) state does (may) depend on the power of the exciting laser. Taken together, our measurements demonstrate the utility of a single-molecule approach to semiconductor defect studies and highlight ZnO as a potential host material for single-defect based applications.

  5. Graphing and grafting graphene: Classifying finite topological defects

    NASA Astrophysics Data System (ADS)

    Cockayne, Eric

    2012-03-01

    The structure of finite-area topological defects in graphene is described in terms of both the direct honeycomb lattice and its dual triangular lattice. Such defects are equivalent to cutting out a patch of graphene and replacing it with a different patch with the same number of dangling bonds. An important subset of these defects, bound by a closed loop of alternating 5- and 7-membered carbon rings, explains most finite-area topological defects that have been experimentally observed. Previously unidentified defects seen in scanning tunneling microscope (STM) images of graphene grown on SiC are identified as isolated divacancies or divacancy clusters.

  6. Oxygen defect processes in silicon and silicon germanium

    NASA Astrophysics Data System (ADS)

    Chroneos, A.; Sgourou, E. N.; Londos, C. A.; Schwingenschlögl, U.

    2015-06-01

    Silicon and silicon germanium are the archetypical elemental and alloy semiconductor materials for nanoelectronic, sensor, and photovoltaic applications. The investigation of radiation induced defects involving oxygen, carbon, and intrinsic defects is important for the improvement of devices as these defects can have a deleterious impact on the properties of silicon and silicon germanium. In the present review, we mainly focus on oxygen-related defects and the impact of isovalent doping on their properties in silicon and silicon germanium. The efficacy of the isovalent doping strategies to constrain the oxygen-related defects is discussed in view of recent infrared spectroscopy and density functional theory studies.

  7. Reconstruction of midfacial defects after surgical resection of malignancies.

    PubMed

    Wells, M D; Luce, E A

    1995-01-01

    Midfacial and orbital defects after ablative oncologic surgery are difficult problems for the reconstructive surgeon. Our goal is to address the devastating functional and aesthetic consequences of these extirpations and to improve the quality of life for this unfortunate group of patients. Partial maxillectomy defects are best treated by skin grafting the residual cavity and reconstructing the maxillary defect by prosthetic means. Local tissues can be used when the defects are small and the bone loss is not extensive. For massive midfacial defects with insufficient bony support for prosthetic reconstruction, osseocutaneous free flaps have proved useful to restore contour and the necessary structural support. PMID:7743712

  8. Directed self-assembly defectivity assessment. Part II

    NASA Astrophysics Data System (ADS)

    Bencher, Chris; Yi, He; Zhou, Jessica; Cai, Manping; Smith, Jeffrey; Miao, Liyan; Montal, Ofir; Blitshtein, Shiran; Lavi, Alon; Dotan, Kfir; Dai, Huixiong; Cheng, Joy Y.; Sanders, Daniel P.; Tjio, Melia; Holmes, Steven

    2012-03-01

    The main concern for the commercialization of directed self-assembly (DSA) for semiconductor manufacturing continues to be the uncertainty in capability and control of defect density. Our research investigates the defect densities of various DSA process applications in the context of a 300mm wafer fab cleanroom environment; this paper expands substantially on the previously published DSA defectivity study by reporting a defect density process window relative to chemical epitaxial pre-pattern registration lines; as well as investigated DSA based contact hole shrinking and report critical dimension statistics for the phase separated polymers before and after etch, along with positional accuracy measurements and missing via defect density.

  9. Oxygen defect processes in silicon and silicon germanium

    SciTech Connect

    Chroneos, A.; Sgourou, E. N.; Londos, C. A.; Schwingenschlögl, U.

    2015-06-15

    Silicon and silicon germanium are the archetypical elemental and alloy semiconductor materials for nanoelectronic, sensor, and photovoltaic applications. The investigation of radiation induced defects involving oxygen, carbon, and intrinsic defects is important for the improvement of devices as these defects can have a deleterious impact on the properties of silicon and silicon germanium. In the present review, we mainly focus on oxygen-related defects and the impact of isovalent doping on their properties in silicon and silicon germanium. The efficacy of the isovalent doping strategies to constrain the oxygen-related defects is discussed in view of recent infrared spectroscopy and density functional theory studies.

  10. Management of a parturient with an uncorrected atrioventricular canal defect.

    PubMed

    Goldsmith, R J; Henderson, J L; Reynolds, J D; Penning, D H

    1998-07-01

    A 24-year-old woman at 37 weeks gestation, with an uncorrected atrioventricular canal defect and incipient congestive heart failure is presented. This rare defect is part of the larger group of endocardial cushion defects. The peripartum anesthetic management of this condition has not been described. Our patient had a large atrial septal defect, a common regurgitant atrioventricular valve, a large left-to-right shunt and a small ventricular septal defect. Her pregnancy was maintained until she developed symptoms of congestive heart failure. We discuss her peripartum management, monitoring and anesthetic choices. PMID:15321214

  11. Topological defect motifs in two-dimensional Coulomb clusters.

    PubMed

    Radzvilavičius, A; Anisimovas, E

    2011-09-28

    We study the distribution of topological defects in two-dimensional Coulomb clusters with parabolic lateral confinement. The minima hopping algorithm based on molecular dynamics is used to efficiently locate the ground- and low-energy metastable states, and their structure is analysed by means of the Delaunay triangulation. The size, structure and distribution of geometry-induced lattice imperfections strongly depends on the system size and the energetic state. Besides isolated disclinations and dislocations, classification of defect motifs includes defect compounds-grain boundaries, rosette defects, vacancies and interstitial particles. Proliferation of defects in metastable configurations destroys the orientational order of the Wigner lattice. PMID:21891854

  12. Complex abdominal wall defects: appearances at prenatal imaging.

    PubMed

    Pakdaman, Reza; Woodward, Paula J; Kennedy, Anne

    2015-01-01

    Abdominal wall defects are a complex group of anomalies, and many are incorrectly diagnosed. Evaluation of the defect relative to the umbilical cord insertion site is fundamentally important in differentiating among the various malformations. The two most common abdominal wall defects are gastroschisis, in which the defect is on the right side of the normally inserting cord and free-floating bowel loops are present, and omphalocele, in which the cord inserts on a membrane-covered midline defect. Omphalocele may also form a portion of a more complex defect that may remain undiagnosed without thorough evaluation. In cloacal exstrophy, the defect extends inferiorly and the bowel loops extrude between the two bladder halves. In pentalogy of Cantrell, the defect extends superiorly and is typically associated with ectopia cordis. Bladder exstrophy is a lower abdominal defect in which the hallmark finding is absence of a fluid-filled bladder. The cord insertion site is normal to low but does not form part of the defect. Both body stalk anomaly and abdominoschisis due to amniotic bands cause severe malformations, often involving extrusion of solid organs and the bowel. Although these two entities have many overlapping features, body stalk anomaly may be recognized on the basis of absence of a free-floating umbilical cord. With use of an algorithmic approach beginning with discovery of the location of the defect, a more precise diagnosis can be determined that may directly affect pre- and postnatal management decisions. PMID:25763744

  13. Investigation of UFO defect on DUV CAR and BARC process

    NASA Astrophysics Data System (ADS)

    Yet, Siew Ing; Ko, Bong Sang; Lee, Soo Man; May, Mike

    2004-05-01

    Photo process defect reduction is one of the most important factors to improve the process stability and yield in sub-0.18um DUV process. In this paper, a new approach to minimize the Deep-UV (DUV) Chemically Amplified Resist (CAR) and Bottom Anti-Reflective Coating (BARC) induced defect known as UFO (UnidentiFied Object) defect will be introduced. These defects have mild surface topography difference on BARC; it only exists on the wide exposed area where there is no photoresist pattern. In this test, Nikon KrF Stepper & Scanner and TEL Clean track were used. Investigation was carried out on the defect formulation on both Acetal and ESCAP type of photoresist while elemental analysis was done by Atomic Force Microscope (AFM) & Auger Electron Spectroscopy (AES). Result indicated that both BARC and photoresist induce this UFO defect; total defect quantity is related with Post Exposure Bake (PEB) condition. Based on the elemental analysis and process-split test, we can conclude that this defect is caused by lack of acid amount and low diffusivity which is related to PAG (Photo Acid Generator) and TAG (Thermal Acid Generator) in KrF photoresist and BARC material. By optimizing photoresist bake condition, this UFO defect as well as other related defect such as Satellite defect could be eliminated.

  14. Evaluation of birth defect histories obtained through maternal interviews.

    PubMed Central

    Rasmussen, S A; Mulinare, J; Khoury, M J; Maloney, E K

    1990-01-01

    Etiologic studies of birth defects often use family history information provided by parents of patients. The validity of this information has not been adequately assessed. Using data from the Atlanta Birth Defects Case-Control study, we evaluated sensitivity, specificity, and positive predictive value of mothers' responses regarding the presence of birth defects in their offspring. A total of 4929 mothers of infants with major structural defects ascertained by the Metropolitan Atlanta Congenital Defects Program and a total of 3,029 mothers of normal infants were asked whether their babies had had a birth defect or a health problem diagnosed during the first year of life. Interviewers and coders of maternal responses were blinded to the case-control status of infants. Sensitivity (the proportion of case mothers who gave responses that could be coded as denoting a major birth defect) was 61%. Specificity (the proportion of control mothers who gave responses that could not be coded as denoting a major birth defect) was 98%. The positive predictive value (the proportion of mothers who gave a major-birth-defect response who in fact had babies with major birth defects) was estimated as 47%. Sensitivity, specificity, and positive predictive value varied by maternal sociodemographic factors such as race and education, as well as by type of defect. These results suggest that family history data obtained through maternal interviews should be cautiously interpreted and, if not properly validated, may alter estimates of recurrence risks. PMID:2309699

  15. Local defect resonance for sensitive non-destructive testing

    NASA Astrophysics Data System (ADS)

    Adebahr, W.; Solodov, I.; Rahammer, M.; Gulnizkij, N.; Kreutzbruck, M.

    2016-02-01

    Ultrasonic wave-defect interaction is a background of ultrasound activated techniques for imaging and non-destructive testing (NDT) of materials and industrial components. The interaction, primarily, results in acoustic response of a defect which provides attenuation and scattering of ultrasound used as an indicator of defects in conventional ultrasonic NDT. The derivative ultrasonic-induced effects include e.g. nonlinear, thermal, acousto-optic, etc. responses also applied for NDT and defect imaging. These secondary effects are normally relatively inefficient so that the corresponding NDT techniques require an elevated acoustic power and stand out from conventional ultrasonic NDT counterparts for their specific instrumentation particularly adapted to high-power ultrasonic. In this paper, a consistent way to enhance ultrasonic, optical and thermal defect responses and thus to reduce an ultrasonic power required is suggested by using selective ultrasonic activation of defects based on the concept of local defect resonance (LDR). A strong increase in vibration amplitude at LDR enables to reliably detect and visualize the defect as soon as the driving ultrasonic frequency is matched to the LDR frequency. This also provides a high frequency selectivity of the LDR-based imaging, i.e. an opportunity of detecting a certain defect among a multitude of other defects in material. Some examples are shown how to use LDR in non-destructive testing techniques, like vibrometry, ultrasonic thermography and shearography in order to enhance the sensitivity of defect visualization.

  16. Controlling Defect Strutures of 8CB by SI Microchannels

    NASA Astrophysics Data System (ADS)

    Pfohl, T.; Li, Y.; Safinya, C. R.; Choi, M. C.; Kim, M. W.; Wen, Z.

    2001-03-01

    We studied the defect structures of smectic 8CB confined in lithographically patterned Si microchannels. Selective surface modifications were carried out to control the wetting contrast of channel surfaces. The 8CB samples were injected at room temperature into the channels and defect structures were observed by polarized microscopy. As a function of decreasing channel depth and width, we observed a systematic transition from spherulitic to focal conic defect textures. The defects become spatially ordered at certain optimal channel width and depth, giving rise to unexpected periodic patterns. Surface modifications appeared to have a large effect on the type of defects as well as the size of the defects. The control of the defect structures by the Si microstructures opens up the possibility of many technological applications including templating and optical switches. (Work supported by NSF-DMR-9972246, NSF-DMR-0076357, ONR-N00014-00-1-0214, UC-Biotech 99-14, and CULAR 99-216)

  17. Repair of fascial defects in dogs using carbon fibers.

    PubMed

    Morris, D M; Hindman, J; Marino, A A

    1998-12-01

    Hernia repair may involve the use of an implant to augment or replace autologous tissue, but the best material for use in this application has not been established. We developed a dog model to evaluate the mechanical strength of fascial defects repaired using carbon fibers, compared with the strength of similar defects repaired using polypropylene mesh (Marlex). Unrepaired defects were included as an additional control. Bilateral defects (1 cm square) were made in the fascia of the back, and the ultimate mechanical strength and stiffness at the repair sites were measured 3-12 months after operation. Defects repaired with carbon fibers were significantly stronger 12 months after operation compared with defects repaired with polypropylene mesh and compared with unrepaired defects. It is concluded that carbon fibers are biocompatible and significantly increase mechanical strength at the repair site. A randomized clinical trial involving patients undergoing hernia repair seems justified to determine whether carbon fibers are superior to standard therapy. PMID:9878328

  18. Native defects in Tl6SI4: Density functional calculations

    DOE PAGESBeta

    Shi, Hongliang; Du, Mao -Hua

    2015-05-05

    In this study, Tl6SI4 is a promising room-temperature semiconductor radiation detection material. Here, we report density functional calculations of native defects and dielectric properties of Tl6SI4. Formation energies and defect levels of native point defects and defect complexes are calculated. Donor-acceptor defect complexes are shown to be abundant in Tl6SI4. High resistivity can be obtained by Fermi level pinning by native donor and acceptor defects. Deep donors that are detrimental to electron transport are identified and methods to mitigate such problem are discussed. Furthermore, we show that mixed ionic-covalent character of Tl6SI4 gives rise to enhanced Born effective charges andmore » large static dielectric constant, which provides effective screening of charged defects and impurities.« less

  19. PREFACE: The International Workshop on Positron Studies of Defects 2014

    NASA Astrophysics Data System (ADS)

    Sugita, Kazuki; Shirai, Yasuharu

    2016-01-01

    The International Workshop on Positron Studies of Defects 2014 (PSD-14) was held in Kyoto, Japan from 14-19 September, 2014. The PSD Workshop brought together positron scientists interested in studying defects to an international platform for presenting and discussing recent results and achievements, including new experimental and theoretical methods in the field. The workshop topics can be characterized as follows: • Positron studies of defects in semiconductors and oxides • Positron studies of defects in metals • New experimental methods and equipment • Theoretical calculations and simulations of momentum distributions, positron lifetimes and other characteristics for defects • Positron studies of defects in combination with complementary methods • Positron beam studies of defects at surfaces, interfaces, in sub-surface regions and thin films • Nanostructures and amorphous materials

  20. Native defects in Tl6SI4: Density functional calculations

    NASA Astrophysics Data System (ADS)

    Shi, Hongliang; Du, Mao-Hua

    2015-05-01

    Tl6SI4 is a promising room-temperature semiconductor radiation detection material. Here, we report density functional calculations of native defects and dielectric properties of Tl6SI4. Formation energies and defect levels of native point defects and defect complexes are calculated. Donor-acceptor defect complexes are shown to be abundant in Tl6SI4. High resistivity can be obtained by Fermi level pinning by native donor and acceptor defects. Deep donors that are detrimental to electron transport are identified and methods to mitigate such problem are discussed. Furthermore, we show that mixed ionic-covalent character of Tl6SI4 gives rise to enhanced Born effective charges and large static dielectric constant, which provides effective screening of charged defects and impurities.

  1. Defect density: a review on the calculation of size program

    NASA Astrophysics Data System (ADS)

    Hasim, Nurdatillah; Abd Rahman, Aedah

    2011-12-01

    Defect density is a measurement conducted in one of Malaysia's ICT leading company. This paper will be discussing on issues of defect density measurement. Regarding defects counted, in order to calculate defect density, we also need to consider the total size of product that is the system size. Generally, defect density is a measure of the number of total defect found divided by the size of the system measured. Therefore, the system size is measured by lines of code. Selected projects in the company have been identified and GeroneSoft Code Counter Pro V1.32 is used as tool to count the lines of code. To this end, the paper presents method used. Analyzed defect density data are represented using control chart because shows the capability of the process so that the achievable goal can be set.

  2. Reconstruction Using Locoregional Flaps for Large Skull Base Defects.

    PubMed

    Hatano, Takaharu; Motomura, Hisashi; Ayabe, Shinobu

    2015-06-01

    We present a modified locoregional flap for the reconstruction of large anterior skull base defects that should be reconstructed with a free flap according to Yano's algorithm. No classification of skull base defects had been proposed for a long time. Yano et al suggested a new classification in 2012. The lb defect of Yano's classification extends horizontally from the cribriform plate to the orbital roof. According to Yano's algorithm for subsequent skull base reconstructive procedures, a lb defect should be reconstructed with a free flap such as an anterolateral thigh free flap or rectus abdominis myocutaneous free flap. However, our modified locoregional flap has also enabled reconstruction of lb defects. In this case series, we used a locoregional flap for lb defects. No major postoperative complications occurred. We present our modified locoregional flap that enables reconstruction of lb defects. PMID:26225296

  3. Application of Principal Component Analysis to EUV multilayer defect printing

    NASA Astrophysics Data System (ADS)

    Xu, Dongbo; Evanschitzky, Peter; Erdmann, Andreas

    2015-09-01

    This paper proposes a new method for the characterization of multilayer defects on EUV masks. To reconstruct the defect geometry parameters from the intensity and phase of a defect, the Principal Component Analysis (PCA) is employed to parametrize the intensity and phase distributions into principal component coefficients. In order to construct the base functions of PCA, a combination of a reference multilayer defect and appropriate pupil filters is introduced to obtain the designed sets of intensity and phase distributions. Finally, an Artificial Neural Network (ANN) is applied to correlate the principal component coefficients of the intensity and the phase of the defect with the defect geometry parameters and to reconstruct the unknown defect geometry parameters.

  4. Concentration of constitutional and thermal defects in UAl4

    NASA Astrophysics Data System (ADS)

    Gargano, P. H.; Kniznik, L.; Alonso, P. R.; Forti, M. D.; Rubiolo, G. H.

    2016-09-01

    The point defect structure of intermetallic compound oI20 UAl4 is investigated using a combination of the statistical mechanical Wagner-Schottky model and first-principles calculations within a projector augmented wave pseudopotential method in conjunction with the generalized gradient approximation. The formation energies of eight point defects were calculated taking into account the four sublattices. The point defect concentrations are calculated as function of temperature and deviation from stoichiometry. Our results show that the aluminum antisite is the constitutional point defect on the Al-rich side. At this off-stoichiometric side the dominant thermal defect is an interbranch defect where four constitutional antisite aluminum atoms are replaced by five uranium vacancies. The point defect effective formation energies are obtained and these results allow us to identify the antistructure bridge mechanism as the most probable for the diffusion for Al atoms in the Al-rich UAl4 intermetallic compound.

  5. The role of point defects and defect complexes in silicon device processing. Summary report and papers

    SciTech Connect

    Sopori, B.; Tan, T.Y.

    1994-08-01

    This report is a summary of a workshop hold on August 24--26, 1992. Session 1 of the conference discussed characteristics of various commercial photovoltaic silicon substrates, the nature of impurities and defects in them, and how they are related to the material growth. Session 2 on point defects reviewed the capabilities of theoretical approaches to determine equilibrium structure of defects in the silicon lattice arising from transitional metal impurities and hydrogen. Session 3 was devoted to a discussion of the surface photovoltaic method for characterizing bulk wafer lifetimes, and to detailed studies on the effectiveness of various gettering operations on reducing the deleterious effects of transition metals. Papers presented at the conference are also included in this summary report.

  6. Anatomic Variability of 120 L5 Spondylolytic Defects

    PubMed Central

    Chen, Michael R.; Moore, Timothy A.; Cooperman, Daniel R.; Lee, Michael J.

    2013-01-01

    Study Design Adult human osteologic specimens were assessed for spondylolytic defects and characterized. Objectives To characterize and determine the prevalence of spondylolytic defects in an osteological collection. Methods Lumbar vertebrae from the Hamann-Todd Osteological Collection at the Cleveland Museum of Natural History were examined. Digital images of specimens with L5 isthmic spondylolytic defects were analyzed, examining the distance of the pars defect in the sagittal plane in relation to the caudal aspect of the pedicle. Results There were 95 bilateral complete (BC), 16 unilateral incomplete (UI), 5 unilateral complete (UC), and 4 unilateral complete defects with an incomplete defect on the contralateral side. The mean distance of BC defects from the pedicle and inferior vertebral end plate was 4.03 mm and 4.88 mm, respectively. The mean distance of the defect from the inferior end plate on the left and right sides were 5.31 mm and 4.44 mm, respectively (p = 0.001, correlation coefficient = 0.56). The mean distance of UI and UC defects from the inferior end plate was 6.38 mm and 2.6 mm, respectively. Conclusion L5 spondylolytic defects were found in 3.87% of the sample. This large-scale description of isthmic spondylolytic defects reveals that significant variability exists in the location of the defect. The anatomic location of the pars defect likely plays a role in the development of L5 nerve root compression and radiculopathy in this clinical scenario. Classifying these defects might allow surgeons to better identify those patients who might benefit from fusion alone without posterior decompression. PMID:24436876

  7. Surface-assisted defect engineering of point defects in ZnO

    NASA Astrophysics Data System (ADS)

    Gorai, Prashun; Ertekin, Elif; Seebauer, Edmund G.

    2016-06-01

    Semiconductor surfaces facilitate the injection of highly mobile point defects into the underlying bulk, thereby offering a special means to manipulate bulk defect concentrations. The present work combines diffusion experiments and first-principles calculations for polar ZnO (0001) surface to demonstrate such manipulation. The rate behavior of oxygen interstitial injection varies dramatically between the Zn- and O-terminated ZnO surfaces. A specific injection pathway for the Zn-terminated surface is identified, and activation barrier determined from the first-principles calculations agrees closely with the experimental activation energy of 1.7 eV.

  8. Neurological susceptibility to a skull defect

    PubMed Central

    Honeybul, Stephen

    2014-01-01

    Background: There continues to be considerable interest in the use of decompressive craniectomy in the management of neurological emergencies. The procedure is technically straightforward; however, it is becoming increasingly apparent that it is associated with significant complications. One complication that has received relatively little attention is the neurological dysfunction that can occur due to the absence of the bone flap and the subsequent distortion of the brain under the scalp as cerebral swelling subsides. The aim of this narrative review was to examine the literature available regarding the clinical features described, outline the proposed pathophysiology for these clinical manifestations and highlight the implications that this may have for rehabilitation of patients with a large skull defect. Methods: A literature search was performed in the MEDLINE database (1966 to June 2012). The following keywords were used: Hemicraniectomy, decompressive craniectomy, complications, syndrome of the trephined, syndrome of the sinking scalp flap, motor trephined syndrome. The bibliographies of retrieved reports were searched for additional references. Results: Various terms have been used to describe the different neurological signs and symptoms with which patients with a skull defect can present. These include; syndrome of the trephined, posttraumatic syndrome, syndrome of the sinking scalp flap, and motor trephined syndrome. There is, however, considerable overlap between the conditions described and a patient's individual clinical presentation. Conclusion: It is becoming increasingly apparent that certain patients are particularly susceptible to the presence of a large skull defect. The term “Neurological Susceptibility to a Skull Defect” (NSSD) is therefore suggested as a blanket term to describe any neurological change attributable to the absence of cranial coverage. PMID:25024883

  9. Management of velopharyngeal defects: a review.

    PubMed

    Shetty, Nitin Bhaskar; Shetty, Sanyuktha; E, Nagraj; D'Souza, Raina; Shetty, Omkar

    2014-03-01

    Success in Maxillofacial Prosthetics depends on full cognizance of the principles that underlie facial harmony, anchorage and retention, weight bearing and leverage, durability, tissue compatibility and tolerance. The maxillofacial prosthodontist normally provides appliances to restore aesthetics and function to the patients who cannot be restored to normal appearances or functions by means of plastic reconstructions. The velopharynx is a dynamic anatomic structure which is essential for normal breathing, eating, and speaking. The soft palate acts as a separator between oral and nasal cavities. Impairment of velopharyngeal function can be caused by insufficiency or incompetency. This article describes in brief about velopharyngeal defects and their management. PMID:24783161

  10. Simple bone augmentation for alveolar ridge defects.

    PubMed

    Haggerty, Christopher J; Vogel, Christopher T; Fisher, G Rawleigh

    2015-05-01

    Dental implant procedures, both surgical placement and preimplant bone augmentation, have become an integral aspect of the oral and maxillofacial surgeon's practice. The number of dental implants placed each year continues to increase as a result of increasing patient exposure and awareness of dental implants, the increased functional and esthetic dental demands of general practitioners and patients, the overall increase in age of the US patient population, and expanded insurance coverage of dental implant-related procedures. This article outlines relevant surgical procedures aimed toward reconstructing alveolar ridge defects to restore intra-arch alveolar discrepancies before restoration-driven dental implant placement. PMID:25951957

  11. Fractionalized topological defects in optical lattices

    NASA Astrophysics Data System (ADS)

    Zhang, Xing-Hai; Fan, Wen-Jun; Shi, Jin-Wei; Kou, Su-Peng

    2015-10-01

    Topological objects are interesting topics in various fields of physics ranging from condensed matter physics to the grand unified and superstring theories. Among those, ultracold atoms provide a playground to study the complex topological objects. In this paper we present a proposal to realize an optical lattice with stable fractionalized topological objects. In particular, we generate the fractionalized topological fluxes and fractionalized skyrmions on two-dimensional optical lattices and fractionalized monopoles on three-dimensional optical lattices. These results offer a new approach to study the quantum many-body systems on optical lattices of ultracold quantum gases with controllable topological defects, including dislocations, topological fluxes and monopoles.

  12. Management of Velopharyngeal Defects: A Review

    PubMed Central

    Shetty, Nitin Bhaskar; Shetty, Sanyuktha; E., Nagraj; D’Souza, Raina; Shetty, Omkar

    2014-01-01

    Success in Maxillofacial Prosthetics depends on full cognizance of the principles that underlie facial harmony, anchorage and retention, weight bearing and leverage, durability, tissue compatibility and tolerance. The maxillofacial prosthodontist normally provides appliances to restore aesthetics and function to the patients who cannot be restored to normal appearances or functions by means of plastic reconstructions. The velopharynx is a dynamic anatomic structure which is essential for normal breathing, eating, and speaking. The soft palate acts as a separator between oral and nasal cavities. Impairment of velopharyngeal function can be caused by insufficiency or incompetency. This article describes in brief about velopharyngeal defects and their management. PMID:24783161

  13. Method of identifying defective particle coatings

    DOEpatents

    Cohen, Mark E.; Whiting, Carlton D.

    1986-01-01

    A method for identifying coated particles having defective coatings desig to retain therewithin a build-up of gaseous materials including: (a) Pulling a vacuum on the particles; (b) Backfilling the particles at atmospheric pressure with a liquid capable of wetting the exterior surface of the coated particles, said liquid being a compound which includes an element having an atomic number higher than the highest atomic number of any element in the composition which forms the exterior surface of the particle coating; (c) Drying the particles; and (d) Radiographing the particles. By television monitoring, examination of the radiographs is substantially enhanced.

  14. Fingerprints of topological defects in a metasurface.

    PubMed

    Kang, Ming; Li, Yongnan; Wang, Hui-Tian

    2014-08-15

    Singularity, representing a structurally stable topological defect (TD), plays a pivotal role in various physical systems. Here we theoretically present the fingerprints of TDs and uncover the resulting exotic optical properties in a tailored metasurface system. The presence of the TDs results in coherent perfect absorption, and dramatic optical property transition from slow to superluminal light behavior when the parameters cross the TD. Our investigation provides a new route to explore many phenomena of the TDs, extends the capabilities of metasurface, and offers benefits to develop potential nanophotonic applications based on the design of the metasurface. PMID:25121898

  15. Iranian physicist 'defects' to the US

    NASA Astrophysics Data System (ADS)

    Gwynne, Peter

    2010-05-01

    An Iranian physicist who disappeared last June during a pilgrimage to Mecca in Saudi Arabia has apparently defected to the US, where he is working for the Central Intelligence Agency (CIA). Shahram Amiri, who did research in nuclear physics at Malek Ashtar University of Technology in Tehran, is thought to be co-operating with the CIA to confirm their intelligence assessments about Iran's nuclear-weapons programme. The CIA has so far kept quiet on the issue and it remains unclear whether Amiri had any connections with Iran's nuclear programme.

  16. Avenues for rehabilitation of auricular defects.

    PubMed

    Nanda, Aditi; Jain, Veena; Kabra, Sri Krishna

    2012-01-01

    Irrespective of the cause, abnormalities in shape, size, and position of body organs are often perceived as looking wrong. This perception can subject the individual to significant peer ridicule and social ostracism. Rehabilitation of patients with auricular defects can either be done by reconstructive surgery or by prosthetic means. The article draws a comparison between the implant-supported prosthesis and reconstructive surgery, listing the benefits, limitations, indications and contraindications of both the techniques. As both the available techniques give excellent results in appropriately selected situations, the restorative team must present all the alternatives to the patient and choose judiciously the better of the two. PMID:22842256

  17. Improve mask inspection capacity with Automatic Defect Classification (ADC)

    NASA Astrophysics Data System (ADS)

    Wang, Crystal; Ho, Steven; Guo, Eric; Wang, Kechang; Lakkapragada, Suresh; Yu, Jiao; Hu, Peter; Tolani, Vikram; Pang, Linyong

    2013-09-01

    As optical lithography continues to extend into low-k1 regime, resolution of mask patterns continues to diminish. The adoption of RET techniques like aggressive OPC, sub-resolution assist features combined with the requirements to detect even smaller defects on masks due to increasing MEEF, poses considerable challenges for mask inspection operators and engineers. Therefore a comprehensive approach is required in handling defects post-inspections by correctly identifying and classifying the real killer defects impacting the printability on wafer, and ignoring nuisance defect and false defects caused by inspection systems. This paper focuses on the results from the evaluation of Automatic Defect Classification (ADC) product at the SMIC mask shop for the 40nm technology node. Traditionally, each defect is manually examined and classified by the inspection operator based on a set of predefined rules and human judgment. At SMIC mask shop due to the significant total number of detected defects, manual classification is not cost-effective due to increased inspection cycle time, resulting in constrained mask inspection capacity, since the review has to be performed while the mask stays on the inspection system. Luminescent Technologies Automated Defect Classification (ADC) product offers a complete and systematic approach for defect disposition and classification offline, resulting in improved utilization of the current mask inspection capability. Based on results from implementation of ADC in SMIC mask production flow, there was around 20% improvement in the inspection capacity compared to the traditional flow. This approach of computationally reviewing defects post mask-inspection ensures no yield loss by qualifying reticles without the errors associated with operator mis-classification or human error. The ADC engine retrieves the high resolution inspection images and uses a decision-tree flow to classify a given defect. Some identification mechanisms adopted by ADC to

  18. Paternal age and the occurrence of birth defects.

    PubMed Central

    Lian, Z H; Zack, M M; Erickson, J D

    1986-01-01

    The association between paternal age and the occurrence of birth defects was studied using data collected in Metropolitan Atlanta. Paternal-age information for babies born with defects was obtained from birth certificates, hospital records, and interviews with mothers; for babies born without defects, the information was obtained from birth certificates. Several statistical techniques were used to evaluate the paternal-age-birth-defects associations for 86 groups of defects. Logistic regression analysis that controlled for maternal age and race indicated that older fathers had a somewhat higher risk for having babies with defects, when all types of defects were combined; an equivalent association for older mothers was not found. Logistic regression analyses also indicated modestly higher risks for older fathers for having babies with ventricular septal defects and atrial septal defects and substantially higher risks for having babies with defects classified in the category chondrodystrophy (largely sporadic achondroplasia) and babies with situs inversus. An association between elevated paternal age and situs inversus has not been reported before; the magnitude of the estimated increased risk for situs inversus was about the same as that found in this study for chondrodystrophy. PMID:3788977

  19. Determination of volatile marker compounds of common coffee roast defects.

    PubMed

    Yang, Ni; Liu, Chujiao; Liu, Xingkun; Degn, Tina Kreuzfeldt; Munchow, Morten; Fisk, Ian

    2016-11-15

    Coffee beans from the same origin were roasted using six time-temperature profiles, in order to identify volatile aroma compounds associated with five common roast coffee defects (light, scorched, dark, baked and underdeveloped). Thirty-seven volatile aroma compounds were selected on the basis that they had previously been identified as potent odorants of coffee and were also identified in all coffee brew preparations; the relative abundance of these aroma compounds was then evaluated using gas chromatography mass spectrometry (GC-MS) with headspace solid phase micro extraction. Some of the 37 key aroma compounds were significantly changed in each coffee roast defect and changes in one marker compound was chosen for each defect type, that is, indole for light defect, 4-ethyl-2-methoxyphenol for scorched defect, phenol for dark defect, maltol for baked defect and 2,5-dimethylfuran for underdeveloped defect. The association of specific changes in aroma profiles for different roast defects has not been shown previously and could be incorporated into screening tools to enable the coffee industry quickly identify if roast defects occur during production. PMID:27283624

  20. Study of post-develop defect on typical EUV resist

    NASA Astrophysics Data System (ADS)

    Harumoto, Masahiko; Suyama, Sadayasu; Miyagi, Tadashi; Morita, Akihiko; Asai, Masaya; Kaneyama, Koji; Itani, Toshiro

    2011-04-01

    This study reports on post-develop defect for EUV resist process. Presently, research and development of EUV resists are continuously being carried out in terms of resolution, sensitivity, LWR. However, in the preparation of EUV lithography for mass-production, research on the reduction of pattern defects, especially post-develop defect is also necessary. As observed during the early stages of resist development for the various lithographic technologies, a large number of pattern defects are commonly coming from the resist dissolution process. As previously reported, utilizing an EUV exposure tool, we have classified several EUV specific defects on exposed and un-exposed area. And also we have reported approaches of defect reduction. In this work, using some types developer solution (TBAH, TBAH+, etc) comparing with current developer solution (TMAH), EUV specific defects were evaluated. Furthermore, we investigated the defect appearing-mechanism and approached defect reduction by track process. Finally, based on these results, the direction of defect reduction approaches applicable for EUV resist processing was discussed.