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Sample records for 16-cm diaphyseal defect

  1. Management of a long segmental defect at the proximal meta-diaphyseal junction of the tibia using a cylindrical titanium mesh cage.

    PubMed

    Ostermann, Peter A W; Haase, Nina; Rübberdt, Alexander; Wich, Michael; Ekkernkamp, Axel

    2002-09-01

    This case report describes a Gustilo Anderson type IIIB tibia fracture associated with extensive segmental bone loss at the proximal meta-diaphyseal junction associated with a tibial plateau fracture and an avulsion of the tibial tubercle. After the tibial plateau fracture was stabilized using cannulated lag screws, the shaft fracture was stabilized using a statically locked intramedullary nail in combination with a cylindrical titanium mesh cage and cancellous bone graft. The soft tissue defect was covered with local flaps. Immediate full weight bearing was initiated, and early functional recovery was achieved. At the final follow-up, plain radiographs demonstrated excellent limb alignment, and bony healing with computed tomography examination revealed bony ingrowth through the cage. This technique may be a reasonable alternative in the treatment of segmental bone loss of long bones.

  2. Three-dimensional printing of rhBMP-2-loaded scaffolds with long-term delivery for enhanced bone regeneration in a rabbit diaphyseal defect.

    PubMed

    Shim, Jin-Hyung; Kim, Se Eun; Park, Ju Young; Kundu, Joydip; Kim, Sung Won; Kang, Seong Soo; Cho, Dong-Woo

    2014-07-01

    In this study, recombinant human bone morphogenetic protein-2 (rhBMP-2) delivery system with slow mode was successfully developed in three-dimensional (3D) printing-based polycaprolactone (PCL)/poly(lactic-co-glycolic acid) (PLGA) scaffolds for bone formation of critical-sized rabbit segmental diaphyseal defect. To control the delivery of the rhBMP-2, collagen (for long-term delivery up to 28 days) and gelatin (for shor-term delivery within a week) solutions encapsulating rhBMP-2 were dispensed into a hollow cylinderical type of PCL/PLGA scaffold. An effective dose of 5μg/mL was determined by measuring the alkaline phosphatase and osteocalcin gene expression levels of human nasal inferior turbinate-derived mesenchymal stromal cells (hTMSCs) seeded on the PCL/PLGA/collagen scaffold in vitro. However, it was found that a burst release of rhBMP-2 from the PCL/PLGA/gelatin scaffold did not induce the osteogenic differentiation of hTMSCs in vitro at an equivalent dose. In the in vivo animal experiements, microcomputed tomography and histological analyses confirmed that PCL/PLGA/collagen/rhBMP-2 scaffolds (long-term delivery mode) showed the best bone healing quality at both weeks 4 and 8 after implantation without inflammatory response. On the other hand, a large number of macrophages indicating severe inflammation provoked by burst release of rhBMP-2 were observed in the vicinity of PCL/PLGA/gelatin/rhBMP-2 (short-term delivery mode) at week 4.

  3. Scintigraphic findings in progressive diaphyseal dysplasia

    SciTech Connect

    Lundy, M.M.; Billingsley, J.L.; Redwine, M.D.; Turnbull, G.L.; Brown, T.J.

    1982-04-01

    A 14-yr-old white male with a severe form of progressive diaphyseal dysplasia (Engelmann-Camurati disease) was referred to our institution for evaluation of splenomegaly, which is not usually associated with the disease. Our studies included bone-marrow, and liver-spleen scans. These scintigraphic findings, along with the probable cause for splenomegaly, are discussed.

  4. Scintigraphic findings in progressive diaphyseal dysplasia

    SciTech Connect

    Lundy, M.M.; Billingsley, M.L.; Redwine, M.D.; Turnbull, G.L.; Brown, T.J.

    1982-04-01

    A 14-yr-old white male with a severe form of progressive diaphyseal dysplasia (Engelmann-Camurati disease) was referred to our institution for evaluation of splenomegaly, which is not usually associated with the disease. Our studies included Tc-99m bone, bone-marrow, and liver-spleen scans. These scintigraphic findings, along with the probable cause for splenomegaly, are discussed.

  5. Mid-diaphyseal Endosteal Thickening With Subsequent Medullary Narrowing in a Patient With Hallermann-Streiff Syndrome

    PubMed Central

    Kaissi, Ali Al; Handelbauer, Albert; Klaushofer, Klaus; Grill, Franz

    2011-01-01

    We report on a 5-year-old girl who presented with the full clinical criteria of Hallermann-Streiff syndrome (HSS). Classically, overtubulation (thin and gracile) bones are the characteristic and constant features in HSS. Interestingly, our present patient manifested unusual mid-diaphyseal endosteal thickening with subsequent medullary narrowing (defective endosteal resorption). To the best of our knowledge no previous reports described such unusual feature in a patient with HSS. Keywords Hallermann-Streiff syndrome; Mid-diaphyseal thickening; Radiology PMID:22393346

  6. Primary diaphyseal tuberculosis of the tibia.

    PubMed

    Chattopadhyay, P; Bandyopadhyay, A; Ghosh, S; Kundu, A J

    2009-06-01

    Tuberculous osteomyelitis involving primarily the diaphysis without articular involvement is very rare. Pain and swelling are the common presenting symptoms. The nonspecific nature of the symptoms leads to a delay in the diagnosis. Radiographs may mimic pyogenic osteomyelitis, Brodie's abscess, tumours or granulomatous lesions. Curettage of the lesion and the histopathological examination of the material obtained are necessary for confirmation of the diagnosis and offer a chance for early healing. We report the successful diagnosis and management of a rare case in a 28-year-old man of Indian origin afflicted with primary diaphyseal tuberculosis of the left tibia.

  7. Fractured diaphyseal tibiofibular synostosis in an adolescent soccer player.

    PubMed

    Santa Maria, Daniel L; Shaw, Thomas; Allen, Marque; Marin, James

    2015-01-01

    Diaphyseal tibiofibular synostosis is a rare cause of symptomatic shin pain with exertion. In this case, a 14-year-old male soccer player presented with atraumatic right shin pain made worse with running. Computed tomography revealed heterotopic ossification, or synostosis, of the tibial-fibular syndesmosis. The patient's symptoms improved with rest, without the need for operative intervention. PMID:25171880

  8. History of operative treatment of forearm diaphyseal fractures.

    PubMed

    Bartoníček, Jan; Kozánek, Michal; Jupiter, Jesse B

    2014-02-01

    Diaphyseal fractures of the forearm have accompanied humanity throughout its history. Nonsurgical techniques dominated the treatment for centuries, and complications including nonunion and malunion were common. The 19th century featured the recognition of distinct injury patterns. With the development of anesthesia and antisepsis, the operative treatment became widespread. In 1878, Heine described fixation of the diaphyseal nonunion of the distal ulna using an intramedullary ivory peg. Parkhill reported on the application of external fixation for forearm fractures in 1897-1898. Hansmann published the case of plate osteosynthesis of an acute fracture of the radius in 1886. In 1913, Schöne published the technique of closed intramedullary fixation of diaphyseal fractures of the forearm using a silver wire. During the first 2 decades of the 20th century, plate osteosynthesis quickly spread across Europe and North America owing to the influence of Lambotte and Lane. After the World War II, plate osteosynthesis became the surgical treatment of choice for forearm diaphyseal fractures.

  9. Progressive diaphyseal dysplasia (Engelmann disease): scintigraphic-radiographic-clinical correlations

    SciTech Connect

    Kumar, B.; Murphy, W.A.; Whyte, M.P.

    1981-07-01

    Four patients (2 males, 2 females; ages 15-47 yrs.) with variable clinical, radiographic, and scintigraphic manifestations of progressive diaphyseal dysplasia (PDD) or Engelmann disease were studied with 99mTc methylene diphosphonate bone imaging and radiographic skeletal surveys. Comparison of the results of the two imaging procedures showed that some affected bones were scintigraphically normal but radiographically abnormal and vice versa. These findings suggest that the lesions of PDD may mature, causing a significant decrease in disease activity, and that abnormally increased radiopharmaceutical accumulation during bone scintigraphy appears to be a sensitive indicator of disease activity.

  10. Articular to diaphyseal proportions of human and great ape metatarsals.

    PubMed

    Marchi, Damiano

    2010-10-01

    This study proposes a new way to use metatarsals to identify locomotor behavior of fossil hominins. Metatarsal head articular dimensions and diaphyseal strength in a sample of chimpanzees, gorillas, orangutans, and humans (n = 76) are used to explore the relationships of these parameters with different locomotor modes. Results show that ratios between metatarsal head articular proportions and diaphyseal strength of the hallucal and fifth metatarsal discriminate among extant great apes and humans based on their different locomotor modes. In particular, the hallucal and fifth metatarsal characteristics of humans are functionally related to the different ranges of motion and load patterns during stance phase in the forefoot of humans in bipedal locomotion. This method may be applicable to isolated fossil hominin metatarsals to provide new information relevant to debates regarding the evolution of human bipedal locomotion. The second to fourth metatarsals are not useful in distinguishing among hominoids. Further studies should concentrate on measuring other important qualitative and quantitative differences in the shape of the metatarsal head of hominoids that are not reflected in simple geometric reconstructions of the articulation, and gathering more forefoot kinematic data on great apes to better understand differences in range of motion and loading patterns of the metatarsals.

  11. Management of adult diaphyseal both-bone forearm fractures.

    PubMed

    Schulte, Leah M; Meals, Clifton G; Neviaser, Robert J

    2014-07-01

    Simultaneous diaphyseal fractures of the radius and ulna, often referred to as both-bone forearm fractures, are frequently encountered by orthopaedic surgeons. Adults with this injury are typically treated with open reduction and internal fixation because of the propensity for malunion of the radius and ulna and the resulting loss of forearm rotation. Large case series support the use of plate and screw fixation for simple fractures. More complex fractures are managed according to strain theory, with the intention of controlling rather than eliminating motion at the fracture site. This can be achieved with flexible plate and screw constructs or intramedullary nails. In general, results of surgical fixation have been good, with only modest losses of forearm strength and rotation. Notable complications include nonunion, malunion, and refracture after device removal. PMID:24966250

  12. Diaphyseal tibiofibular synostosis in professional athletes: Report of 2 cases.

    PubMed

    Sonnery-Cottet, B; Alessio-Mazzola, M; Luz, B F; Barbosa, N C; Tuteja, S; Kajetanek, C; Dellal, A; Thaunat, M

    2016-02-01

    Anterior leg pain is common in professional athletes and tibiofibular synostosis is reported to be a rare cause of anterior compartment pain or ankle pain related to sports activities. The management and appropriate treatment of this condition in professional athletes is controversial and the literature on the topic is sparse. Distal synostosis is usually related to ankle sprain and syndesmotic ligament injury, and proximal synostosis has been linked to leg length discrepancy and exostosis. Mid-shaft synostosis is even less common than proximal and distal forms. We present the treatment of mid-shaft tibiofibular synostosis in 2 cases of professional athletes (soccer and basketball player), along with a review of the literature. When diaphyseal synostosis is diagnosed, first-line conservative treatment, including ultrasound-guided steroid injection is recommended. However, if it does not respond to conservative management, surgical resection may be indicated to relieve symptoms.

  13. Proximal femoral diaphyseal cross-sectional geometry in Orrorin tugenensis.

    PubMed

    Bleuze, M

    2012-06-01

    Functional adaptations in femora attributed to Orrorin tugenensis provide a unique opportunity to examine locomotor behavior very early in the hominin lineage. This study examines relative cortical thickness, cortical area (CA) relative to the polar moment of area (J), and J relative to femoral head superoinferior diameter (FHD) in the proximal femur of O. tugenensis (BAR 1002'00 and BAR 1003'00), and compares patterns in this early hominin with those in a sample of modern humans (N=31), Plio-Pleistocene fossil hominins (N=8), Pan troglodytes troglodytes (N=13), and Pan paniscus (N=3). Relative cortical thickness and CA relative to J in the proximal femur of O. tugenensis are comparable to patterns generally found in other fossil hominins. Proximal femoral diaphyseal J relative to FHD in BAR 1002'00 is similar to patterns found in fossil hominins typically attributed to a non-Homo genus (i.e. SK 82, SK 97, and KNM-ER 738). Cross-sectional geometric patterns in the proximal femur of Orrorin are not unlike those generally found in australopithecines and fossil Homo. While the results of this study cannot confirm unequivocally that Orrorin was an obligate biped, a mode of locomotion comparable to that proposed for australopithecines cannot be ruled out. PMID:22609080

  14. Proximal femoral diaphyseal cross-sectional geometry in Orrorin tugenensis.

    PubMed

    Bleuze, M

    2012-06-01

    Functional adaptations in femora attributed to Orrorin tugenensis provide a unique opportunity to examine locomotor behavior very early in the hominin lineage. This study examines relative cortical thickness, cortical area (CA) relative to the polar moment of area (J), and J relative to femoral head superoinferior diameter (FHD) in the proximal femur of O. tugenensis (BAR 1002'00 and BAR 1003'00), and compares patterns in this early hominin with those in a sample of modern humans (N=31), Plio-Pleistocene fossil hominins (N=8), Pan troglodytes troglodytes (N=13), and Pan paniscus (N=3). Relative cortical thickness and CA relative to J in the proximal femur of O. tugenensis are comparable to patterns generally found in other fossil hominins. Proximal femoral diaphyseal J relative to FHD in BAR 1002'00 is similar to patterns found in fossil hominins typically attributed to a non-Homo genus (i.e. SK 82, SK 97, and KNM-ER 738). Cross-sectional geometric patterns in the proximal femur of Orrorin are not unlike those generally found in australopithecines and fossil Homo. While the results of this study cannot confirm unequivocally that Orrorin was an obligate biped, a mode of locomotion comparable to that proposed for australopithecines cannot be ruled out.

  15. Rare Proximal Diaphyseal Stress Fractures of the Fifth Metatarsal Associated With Metatarsus Adductus.

    PubMed

    Wamelink, Kyle E; Marcoux, John T; Walrath, Scott M

    2016-01-01

    Before the report of English surgeon Robert Jones, who sustained a fracture to his fifth metatarsal while dancing around a tent pole, metatarsal fractures were thought to be the result of direct trauma to the foot. The mechanism of metatarsal fractures, in particular, those involving the fifth metatarsal, is now well understood. Patients with an adducted alignment of their forefoot can overload the fifth metatarsal base, putting them at an increased risk of fractures of this bone. Studies have reported that 2 distinct types of proximal diaphyseal or junctional fractures of the fifth metatarsal occur: the acute proximal diaphyseal or transverse proximal diaphyseal fracture and the proximal diaphyseal stress fracture. The radiographic characteristics associated with proximal diaphyseal stress fractures of the fifth metatarsal can vary by the chronicity; however, the findings typically entail a radiolucent fracture line with surrounding reactive sclerosis. In addition, a reduced medullary canal width can be appreciated. In the present retrospective analysis of patients with stress-related trauma to the fifth metatarsal base with an adducted forefoot, 2012 foot trauma cases were reviewed at 3 separate institutions. Of the 2012 cases, 22 (1.11%) met the outlined criteria of stress fractures of the fifth metatarsal base and underlying metatarsus adductus. PMID:27066870

  16. Atypical femoral diaphyseal and subtrochanteric fractures and their association with bisphosphonates

    PubMed Central

    Leung, Frankie; Lau, Tak-Wing; To, Michael; Luk, Keith Dip-Kei; Kung, Annie Wai Chee

    2009-01-01

    Antiresorptive bisphosphonate agents are the mainstay of treatment for osteoporosis in both men and postmenopausal women. However, recent studies have raised concerns about the oversuppression of bone turnover related to the long-term use of bisphosphonates. Cases of atypical femoral diaphyseal and subtrochanteric fracture were reported recently in patients on long-term alendronate, and oversuppression of bone turnover was postulated to be the cause. We retrospectively reviewed all patients with femoral diaphyseal and subtrochanteric fracture presented between July 2003 and June 2008, and identified 10 patients who reported prior bisphosphonate use. Bone formation markers of all these patients were in the low range. Although the incidence of bisphosphonate-related atypical fracture accounts for an extremely low percentage of the total number of femoral diaphyseal and subtrochanteric fractures, we observed a steady increase from 0% in 2003 to 2004 to 25% in 2007 to 2008. PMID:21686468

  17. Role of Nonbehavioral Factors in Adjusting Long Bone Diaphyseal Structure in Free-ranging Pan troglodytes.

    PubMed

    Carlson, K J; Sumner, D R; Morbeck, M E; Nishida, T; Yamanaka, A; Boesch, C

    2008-12-01

    Limb bones deform during locomotion and can resist the deformations by adjusting their shapes. For example, a tubular-shaped diaphysis best resists variably-oriented deformations. As behavioral profiles change during adulthood, patterns of bone deformation may exhibit age trends. Habitat characteristics, e.g., annual rainfall, tree density, and elevation changes, may influence bone deformations by eliciting individual components of behavioral repertoires and suppressing others, or by influencing movements during particular components. Habituated chimpanzee communities provide a unique opportunity to examine these factors because of the availability of morphological data and behavioral observations from known-age individuals inhabiting natural habitats. We evaluated adult femora and humeri of 18 female and 10 male free-ranging chimpanzees (Pan troglodytes) from communities in Gombe (Tanzania), Mahale Mountains (Tanzania), and Taï Forest (Côte d'Ivoire) National Parks. We compare cross sections at several locations (35%, 50%, 65% diaphyseal lengths). Community comparisons highlight different diaphyseal shapes of Taï females relative to Mahale and Gombe females, particularly in humeral diaphyses. Age trends in diaphyseal shapes are consistent with reduced activity levels in general, not only reduced arboreal activity. Age-related bone loss is apparent among community females, but is less striking among males. Community trends in diaphyseal shape are qualitatively consistent with ranked annual rainfall at localities, tree density, and elevation change or ruggedness of terrain. Habitat characteristics may contribute to variation in diaphyseal shape among chimpanzee communities, much like among modern human groups, but verification awaits further rigorous experimental and comparative analyses.

  18. [Treatment of humeral diaphyseal fractures in adults using centro-medullary pinning. Operative technic and indications].

    PubMed

    de la Caffinière, J Y; Kassab, G; Ould Ouali, A

    1988-01-01

    The ascending intramedullary "pinning" technique is known for twenty-five years. Theoretically successful for the diaphyseal humeral fractures in adults, it appeared until now with some disadvantages which limited its use. By adding some modifications, the authors show that this technique is worthwhile in dislocation fractures in adults. PMID:3253848

  19. Outcome of limb reconstruction system in open tibial diaphyseal fractures

    PubMed Central

    Ajmera, Anand; Verma, Ankit; Agrawal, Mukul; Jain, Saurabh; Mukherjee, Arunangshu

    2015-01-01

    Background: Management of open tibial diaphyseal fractures with bone loss is a matter of debate. The treatment options range from external fixators, nailing, ring fixators or grafting with or without plastic reconstruction. All the procedures have their own set of complications, like acute docking problems, shortening, difficulty in soft tissue management, chronic infection, increased morbidity, multiple surgeries, longer hospital stay, mal union, nonunion and higher patient dissatisfaction. We evaluated the outcome of the limb reconstruction system (LRS) in the treatment of open fractures of tibial diaphysis with bone loss as a definative mode of treatment to achieve union, as well as limb lengthening, simultaneously. Materials and Methods: Thirty open fractures of tibial diaphysis with bone loss of at least 4 cm or more with a mean age 32.5 years were treated by using the LRS after debridement. Distraction osteogenesis at rate of 1 mm/day was done away from the fracture site to maintain the limb length. On the approximation of fracture ends, the dynamized LRS was left for further 15-20 weeks and patient was mobilized with weight bearing to achieve union. Functional assessment was done by Association for the Study and Application of the Methods of Illizarov (ASAMI) criteria. Results: Mean followup period was 15 months. The mean bone loss was 5.5 cm (range 4-9 cm). The mean duration of bone transport was 13 weeks (range 8-30 weeks) with a mean time for LRS in place was 44 weeks (range 24-51 weeks). The mean implant index was 56.4 days/cm. Mean union time was 52 weeks (range 31-60 weeks) with mean union index of 74.5 days/cm. Bony results as per the ASAMI scoring were excellent in 76% (19/25), good in 12% (3/25) and fair in 4% (1/25) with union in all except 2 patients, which showed poor results (8%) with only 2 patients having leg length discrepancy more than 2.5 cm. Functional results were excellent in 84% (21/25), good in 8% (2/25), fair in 8% (2/25). Pin tract

  20. Biomechanical Strength of Large Diaphyseal Deep-frozen Allografts.

    PubMed

    Nather, A; Goh, J C

    2000-01-01

    The aim of this paper is to study the biomechanical strength of deep-frozen allografts as they heal. Twenty-eight adult cats were used with the tibia as the experimental model site. Deep-frozen allografts stored at -80 degrees C were used to reconstruct a large tibial defect (at least two-thirds of the diaphysis). An intra-medullary rod was used for fixation. The healing was studied by X-ray at observation periods of 4, 6, 8, 12, 16, 24 and 36 weeks. Post-transplantation biomechanical testing was performed using the Shimadzu Universal Testing Machine DCS series with a torsion test device of 50 kg force metre. Parameters studied included maximum torque, torsional stiffness and energy of absorption. The transplanted grafts were compared to the mechanical properties of the internal controls of the normal opposite tibia of each cat. The results of the mechanical tests demonstrated that deep-frozen allografts did not regain normal strength. At nine months, only about 60% of normal torque strength and about 80% of normal torsional stiffness was achieved. Clinically, it is important to employ strong and rigid internal fixation using intra-medullary nailing rather than plating to allow for immediate mobilisation and reduce the rate of graft fracture.

  1. Taxonomic identification of Lower Pleistocene fossil hominins based on distal humeral diaphyseal cross-sectional shape.

    PubMed

    Lague, Michael R

    2015-01-01

    The coexistence of multiple hominin species during the Lower Pleistocene has long presented a challenge for taxonomic attribution of isolated postcrania. Although fossil humeri are well-suited for studies of hominin postcranial variation due to their relative abundance, humeral articular morphology has thus far been of limited value for differentiating Paranthropus from Homo. On the other hand, distal humeral diaphyseal shape has been used to justify such generic distinctions at Swartkrans. The potential utility of humeral diaphyseal shape merits larger-scale quantitative analysis, particularly as it permits the inclusion of fragmentary specimens lacking articular morphology. This study analyzes shape variation of the distal humeral diaphysis among fossil hominins (c. 2-1 Ma) to test the hypothesis that specimens can be divided into distinct morphotypes. Coordinate landmarks were placed on 3D laser scans to quantify cross-sectional shape at a standardized location of the humeral diaphysis (proximal to the olecranon fossa) for a variety of fossil hominins and extant hominids. The fossil sample includes specimens attributed to species based on associated craniodental remains. Mantel tests of matrix correlation were used to assess hypotheses about morphometric relationships among the fossils by comparing empirically-derived Procrustes distance matrices to hypothetical model matrices. Diaphyseal shape variation is consistent with the hypothesis of three distinct morphotypes (Paranthropus, Homo erectus, non-erectus early Homo) in both eastern and southern Africa during the observed time period. Specimens attributed to non-erectus early Homo are unique among hominids with respect to the degree of relative anteroposterior flattening, while H. erectus humeri exhibit morphology more similar to that of modern humans. In both geographic regions, Paranthropus is characterized by a morphology that is intermediate with respect to those morphological features that differentiate

  2. Atypical Fractures are Mainly Subtrochanteric in Singapore and Diaphyseal in Sweden: A Cross-Sectional Study.

    PubMed

    Schilcher, Jörg; Howe, Tet Sen; Png, Meng Ai; Aspenberg, Per; Koh, Joyce S B

    2015-11-01

    We have previously noted a dichotomy in the location of atypical fractures along the femoral shaft in Swedish patients, and a mainly subtrochanteric location of atypical fractures in descriptions of patients from Singapore. These unexpected differences were now investigated by testing the following hypotheses in a cross-sectional study: first, that there is a dichotomy also in Singapore; second, that the relation between subtrochanteric and diaphyseal location is different between the two countries; third, that the location is related to femoral bow. The previously published Swedish sample (n = 151) was re-measured, and a new Singaporean sample (n = 75) was established. Both samples were based on radiographic classification of all femoral fractures in women above 55 years of age. The distance between the fracture line and the lesser trochanter was measured. Femoral bow was classified as present or absent on frontal radiographs. Frequency distribution of the measured distances was analyzed using the Bayesian information criterion to choose the best description of the observed variable distribution in terms of a compilation of normally distributed subgroups. The analysis showed a clear dichotomy of the fracture location: either subtrochanteric or diaphyseal. Subtrochanteric fractures comprised 48% of all fractures in Singapore, and 17% in Sweden (p = 0.0001). In Singapore, femoral bow was associated with more fractures in the diaphyseal subgroup (p = 0.0001). This was not seen in Sweden. A dichotomous location of atypical fractures was confirmed, because it was found also in Singapore. The fractures showed a different localization pattern in the two countries. This difference may be linked to anatomical variations, but might also be related to cultural differences between the two populations that influence physical activity.

  3. Taxonomic identification of Lower Pleistocene fossil hominins based on distal humeral diaphyseal cross-sectional shape

    PubMed Central

    2015-01-01

    The coexistence of multiple hominin species during the Lower Pleistocene has long presented a challenge for taxonomic attribution of isolated postcrania. Although fossil humeri are well-suited for studies of hominin postcranial variation due to their relative abundance, humeral articular morphology has thus far been of limited value for differentiating Paranthropus from Homo. On the other hand, distal humeral diaphyseal shape has been used to justify such generic distinctions at Swartkrans. The potential utility of humeral diaphyseal shape merits larger-scale quantitative analysis, particularly as it permits the inclusion of fragmentary specimens lacking articular morphology. This study analyzes shape variation of the distal humeral diaphysis among fossil hominins (c. 2-1 Ma) to test the hypothesis that specimens can be divided into distinct morphotypes. Coordinate landmarks were placed on 3D laser scans to quantify cross-sectional shape at a standardized location of the humeral diaphysis (proximal to the olecranon fossa) for a variety of fossil hominins and extant hominids. The fossil sample includes specimens attributed to species based on associated craniodental remains. Mantel tests of matrix correlation were used to assess hypotheses about morphometric relationships among the fossils by comparing empirically-derived Procrustes distance matrices to hypothetical model matrices. Diaphyseal shape variation is consistent with the hypothesis of three distinct morphotypes (Paranthropus, Homo erectus, non-erectus early Homo) in both eastern and southern Africa during the observed time period. Specimens attributed to non-erectus early Homo are unique among hominids with respect to the degree of relative anteroposterior flattening, while H. erectus humeri exhibit morphology more similar to that of modern humans. In both geographic regions, Paranthropus is characterized by a morphology that is intermediate with respect to those morphological features that differentiate

  4. Oblique wedge osteotomy for femoral diaphyseal deformity in fibrous dysplasia: a case report.

    PubMed

    Yamamoto, T; Hashimoto, Y; Mizuno, K

    2001-03-01

    A patient with fibrous dysplasia who had a three-dimensional diaphyseal deformity in the left femur was treated using an oblique wedge osteotomy. The patient was 26-year-old man with a history of two pathologic fractures in the midshaft of the femur. A 22 degrees angular deformity in the coronal plane and 15 degrees anterior bowing were corrected. The results at a followup 2 years after surgery were satisfactory in functional and radiologic terms. The technique and advantages of the oblique wedge osteotomy are discussed. PMID:11249172

  5. Microstructure and micromechanical properties of the mid-diaphyses of human fetal femurs.

    PubMed

    Su, X W; Feng, Q L; Cui, F Z; Zhu, X D

    1997-01-01

    The microstructure, composition and the micromechanical properties across the thickness of femoral mid-diaphyses from 14 to 26 week human fetuses have been investigated. Scanning electron microscopy and transmission electron microscopy were employed to examine structural changes with maturation. The fetal bones consist of layers of woven bone. From young to old fetuses and from outer to inner bone layers, the collagen fibrils become more cross-linked, densely packed and change from disordered to an ordered arrangement. The collagen fibril bundles are also more preferentially oriented and change from a chiefly circumferential to longitudinal direction. The sizes of the apatite crystals also increase with age. The Ca/P ratio remains constant around 1.55 for all the bone layers except the outmost layer which is lower than 1.2. An nano-indenter was used to evaluate the microhardness and elastic modulus of each bone layer. The increase of microhardness and elastic modulus correlates with the maturation of bone. The mechanical properties of the mid-diaphyses of human fetal femurs are anisotropic, which is due to the preferential orientation of collagen fibrils.

  6. The pattern of femoral diaphyseal fractures in children admitted in Sarawak General Hospital.

    PubMed

    Rasit, A H; Mohammad, A W; Pan, K L

    2006-02-01

    Trend towards changing the face of management for pediatric femoral fractures tends to advocate operative treatment. This study was undertaken to review our current practice in the wake of recent progress in the management of pediatric femoral fractures. Fifty patients with femoral diaphyseal fracture treated in Sarawak General Hospital were reviewed retrospectively after an average follow-up of 2.6 years. There were 36 boys and 14 girls, with a mean age of 6.2 years (range five months to 14 years). Children under six years of age constituted the majority of the patients. Half of the fractures were caused by road traffic accident. Nine patients had associated injuries. The most common site of fracture was at the middle third (N=31). The treatment regimens were delayed hip spica (DHS) in 16, immediate hip spica (IHS) in 24, plate osteosynthesis (PO) in five, titanium elastic nailing (TEN) in five, and external fixation (EF) in one. The minimum hospital stay was two days, and the maximum 33 days (mean, 9.7 days). Malunion was the commonest complication. Conservative treatment is the preferred option for children under six years of age. It is cost-effective with minimal complication. The other treatment options are reserved for specific indication in older children. Diaphyseal fractures of the femur in children can be adequately managed non-operatively.

  7. [Counter-lateral compression in oblique pseudarthroses of diaphyses of the tubular bones of the lower limbs].

    PubMed

    Kravchuk, V I

    1976-06-01

    The author reports the results of treatment in 58 patients with oblique aplastic pseudarthrosis of tubular bones diaphyses of the lower limbs. For treatment extrafocal with counter-lateral compression by means of pins with bearing surfaces. By the present time nearly in all patients (52 of 58) with the mentioned complications such kind of treatment resulted in rehabilitation of the main motion-bearing function of the extremity.

  8. Low-energy diaphyseal femoral fractures associated with bisphosphonate use and severe curved femur: a case series.

    PubMed

    Sasaki, Satoshi; Miyakoshi, Naohisa; Hongo, Michio; Kasukawa, Yuji; Shimada, Yoichi

    2012-09-01

    Recent reports have raised concerns about low-energy subtrochanteric and diaphyseal femoral fractures after long-term bisphosphonate treatment, which may be associated with severely suppressed bone turnover (SSBT). However, diaphyseal femoral fractures without bisphosphonate treatment have also been reported in patients with severely curved femur, which are commonplace in the elderly. The purpose of this study was therefore to investigate associations between occurrence of such fractures, bisphosphonate use, and curvature of the femur. Nine consecutive elderly patients treated for low-energy diaphyseal femoral fractures between 2005 and 2010 were retrospectively reviewed. Three patients sustained bilateral fractures. Eight patients were administered bisphosphonates and one patient was administered raloxifene. Duration of osteoporosis treatment, type of fractures, surgical procedure, cortical thickness and curvature of opposite femur were evaluated. The cortical thickness and femoral curvature were further compared with those of 24 control subjects without fractures. The mean duration of drug administration was 3.6 years. All fractures showed similar X-ray patterns of simple transverse fracture with medial spike. Only one femur showed thickening of the femoral cortex. One case was treated with locking plate fixation, while the other cases were operated with intramedullary nails (9 antegrade nails, 2 retrograde nails). One femur treated with retrograde nail showed delayed bone union. The femoral curvature was significantly higher in the low-energy fracture group than the control group (P < 0.01); however, cortical thickness did not show a significant difference between the groups. In addition to SSBT, increased femoral curvature might be a causative factor for low-energy diaphyseal femoral fracture in the elderly.

  9. Long-term anabolic effects of prostaglandin-E2 on tibial diaphyseal bone in male rats

    NASA Technical Reports Server (NTRS)

    Jee, Webster S. S.; Ke, Hua Zhu; Li, Xiao Jian

    1991-01-01

    The effects of long-term prostaglandin E2 (PGE2) on tibial diaphyseal bone were studied in 7-month-old male Sprague-Dawley rats given daily subcutaneous injections of 0, 1, 3 and 6 mg PGE2/kg/day for 60, 120 and 180 days. The tibial shaft was measured by single photon absorptiometry and dynamic histomorphometric analyses were performed on double-fluorescent labeled undecalcified tibial diaphyseal bone samples. Exogenous PGE2 administration produced the following transient changes in a dose-response manner between zero and 60 days: (1) increased bone width and mineral density; (2) increased total tissue and total bone areas; (3) decreased marrow area; (4) increased periosteal and corticoendosteal lamellar bone formation; (5) activated corticoendosteal lamellar and woven trabecular bone formation; and (6) activated intracortical bone remodeling. A new steady-state of increased tibial diaphyseal bone mass and elevated bone activities were observed from day 60 onward. The elevated bone mass level attained after 60 days of PGE2 treatment was maintained at 120 and 180 days. These observations indicate that the powerful anabolic effects of PGE2 will increase both periosteal and corticoendosteal bone mass and sustain the transient increase in bone mass with continuous daily administration of PGE2.

  10. [Infection following centro-medullary nailing of diaphyseal femoral and tibial fractures].

    PubMed

    Lortat-Jacob, A; Sutour, J M; Beaufils, P

    1986-01-01

    The authors have treated 51 cases of infection arising after intramedullary nailing of the femur or tibia. In 3 cases amputation was required, 48 united, but 10 were still draining. The final result was obtained after an average of 15 months. An average of four procedures per patient were needed. All the cases were septic non-unions at the onset of treatment, except 18 cases which had already united. In these cases, simple removal of the femoral nail led to rapid healing. In contrast, healing was less easy to obtain in the tibia. In 33 septic non-unions, 12 femoral and 21 tibial, the best results at the femoral level were obtained by retaining the nail in situ. At the tibial level, retention of the nail was rarely followed by bony union. Removal of the nail and the use of external fixation gave good results for the infection, but rarely resulted in bony union (1 case out of 14). The failures were treated by further operation of bone resection and grafting. The authors recommend, in cases of tibial septic non-union after nailing that primary removal of the nail should be associated with bony resection and external fixation, followed by reconstructive grafting, either by open cancellous grafting extending to the fibula or conventional tibio fibular grafting. In 8 cases, 7 in the femur and 1 in the tibia, the infection extended throughout the entire diaphysis and in 3 of these cases, a large diaphyseal resection was required. PMID:3823510

  11. [Therapy of diaphyseal fractures of the leg in a district hospital].

    PubMed

    Pavlícek, B

    1993-02-01

    During the period between 1987 and 1991 at the surgical department of the Trebíc hospital 136 casualties with closed diaphyseal fractures were treated. All patients were older than 18 years and monotraumas were involved. The patients were treated by immobilization by a classical high plaster bandage, functional plaster as recommended by Sarmient, extension treatment, miniosteosynthesis, osteosynthesis using a splint, intramedullary fixation as described by Küntscher and Simon-Enders-Weidner, or possibly by a combination of the mentioned methods. The author divides fractures of the leg into stable and unstable fractures and fracture with so-called urgently indicated osteosynthesis. The mean period of treatment with high plaster bandage was 31.7 weeks, functional plaster according to Sarmient 20.2 weeks, miniosteosynthesis with plaster fixation 25.5 weeks. When splints were used, the mean period of treatment was 30.5 weeks, in osteosynthesis according to Enders 20.6 weeks. The best results in stable fractures were achieved by functional plaster according to Sarmient, in unstable fractures and those with indicated osteosynthesis by using intramedullary fixation as described by Enders. PMID:8211388

  12. An RNA-seq Protocol to Identify mRNA Expression Changes in Mouse Diaphyseal Bone: Applications in Mice with Bone Property Altering Lrp5 Mutations

    PubMed Central

    Ayturk, Ugur M.; Jacobsen, Christina M.; Christodoulou, Danos C.; Gorham, Joshua; Seidman, Jonathan G.; Seidman, Christine E.; Robling, Alexander G.; Warman, Matthew L.

    2013-01-01

    Loss-of-function and certain missense mutations in the Wnt co-receptor LRP5 significantly decrease or increase bone mass, respectively. These human skeletal phenotypes have been recapitulated in mice harboring Lrp5 knockout and knockin mutations. We hypothesized that measuring mRNA expression in diaphyseal bone from mice with Lrp5 wild-type (Lrp5+/+), knockout (Lrp5−/−), and high bone mass (HBM)-causing (Lrp5p.A214V/+) alleles could identify genes and pathways that regulate or are regulated by LRP5 activity. We performed RNA-seq on pairs of tibial diaphyseal bones from four 16-week-old mice with each of the aforementioned genotypes. We then evaluated different methods for controlling for contaminating non-skeletal tissue (i.e., blood, bone marrow, and skeletal muscle) in our data. These methods included pre-digestion of diaphyseal bone with collagenase and separate transcriptional profiling of blood, skeletal muscle and bone marrow. We found that collagenase digestion reduced contamination, but also altered gene expression in the remaining cells. In contrast, in silico filtering of the diaphyseal bone RNA-seq data for highly expressed blood, skeletal muscle, and bone marrow transcripts significantly increased the correlation between RNA-seq data from an animal’s right and left tibiae and from animals with the same Lrp5 genotype. We conclude that reliable and reproducible RNA-seq data can be obtained from mouse diaphyseal bone and that lack of LRP5 has a more pronounced effect on gene expression than the HBM-causing LRP5 missense mutation. We identified 84 differentially expressed protein-coding transcripts between LRP5 “sufficient” (i.e., Lrp5+/+ and Lrp5p.A214V/+) and “insufficient” (Lrp5−/−) diaphyseal bone, and far fewer differentially expressed genes between Lrp5p.A214V/+ and Lrp5+/+ diaphyseal bone. PMID:23553928

  13. The locomotion of Babakotia radofilai inferred from epiphyseal and diaphyseal morphology of the humerus and femur.

    PubMed

    Marchi, Damiano; Ruff, Christopher B; Capobianco, Alessio; Rafferty, Katherine L; Habib, Michael B; Patel, Biren A

    2016-09-01

    Palaeopropithecids, or "sloth lemurs," are a diverse clade of large-bodied Malagasy subfossil primates characterized by their inferred suspensory positional behavior. The most recently discovered genus of the palaeopropithecids is Babakotia, and it has been described as more arboreal than Mesopropithecus, but less than Palaeopropithecus. In this article, the within-bone and between-bones articular and cross-sectional diaphyseal proportions of the humerus and femur of Babakotia were compared to extant lemurs, Mesopropithecus and Palaeopropithecus in order to further understand its arboreal adaptations. Additionally, a sample of apes and sloths (Choloepus and Bradypus) are included as functional outgroups composed of suspensory adapted primates and non-primates. Results show that Babakotia and Mesopropithecus both have high humeral/femoral shaft strength proportions, similar to extant great apes and sloths and indicative of forelimb suspensory behavior, with Babakotia more extreme in this regard. All three subfossil taxa have relatively large femoral heads, also associated with suspension in modern taxa. However, Babakotia and Mesopropithecus (but not Palaeopropithecus) have relatively small femoral head surface area to shaft strength proportions suggesting that hind-limb positioning in these taxa during climbing and other behaviors was different than in extant great apes, involving less mobility. Knee and humeral articular dimensions relative to shaft strengths are small in Babakotia and Mesopropithecus, similar to those found in modern sloths and divergent from those in extant great apes and lemurs, suggesting more sloth-like use of these joints during locomotion. Mesopropithecus and Babakotia are more similar to Choloepus in humerofemoral head and length proportions while Palaeopropithecus is more similar to Bradypus. These results provide further evidence of the suspensory adaptations of Babakotia and further highlight similarities to both extant suspensory

  14. Treatment of Bone Defects in War Wounds: Retrospective Study

    PubMed Central

    Grubor, Predrag; Milicevic, Snjezana; Grubor, Milan; Meccariello, Luigi

    2015-01-01

    Introduction: Results of the treatment of open fractures primarily depend on the treatment of connected soft tissue injuries. Objective: The aim was to present the experience and methods gained during the treatment of diaphyseal bone defects as a consequence of gunshot fracture soft war trauma. Patients and Methods: The study consisted of 116 patients with the diaphyseal bone defect who were treated with the usage of primary and delayed autotransplantation of bones, transplants of the fibula and Ilizarov distraction osteogenesis. Results: The results of compensation of bone defect less than 4 cm and conducted by an early cortico-spongioplastics were as follows: good in 8 respondents (45%), satisfactory in 6 (34%) and poor in 4 respondents (21%). In cases of delayed cortico-spongioplastics, the above mentioned results were: good in 36 (41%) respondents, satisfactory in 24 (34%) and poor in 16 (25%) respondents. The results of compensation of bone defect greater than 4 cm with the usage of fibular transplant were as follows: good in 3 (38%) respondents, satisfactory in 3 (38%) and poor in 2 (24%), and with the usage of using the Ilizarov method, the results were as follows: good in 8 (57%) respondents, satisfactory in 3 (21.5%) and poor in 3(21.5%) respondents. Conclusion: The results showed that, in cases of compensation of bone defects less than 4 cm, the advantage is given to the primary spongioplastics over the delayed one. In cases of compensation of bone defects greater than 4 cm, the advantage is given to the Ilizarov distraction osteogenesis when compared to the fibular transplant. PMID:26543315

  15. 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 ...

  16. Age estimation of immature human skeletal remains from the diaphyseal length of the long bones in the postnatal period.

    PubMed

    Cardoso, Hugo F V; Abrantes, Joana; Humphrey, Louise T

    2014-09-01

    Age at death in immature human skeletal remains has been estimated from the diaphyseal length of the long bones, but few studies have actually been designed specifically for the purpose of age estimation and those which have, show important caveats. This study uses regression and classical calibration to model the relationship between age and diaphyseal length of the six long bones, in a sample of 184 known sex and age individuals (72 females and 112 males), younger than 13 years of age, selected from Portuguese and English skeletal collections. Age estimation models based on classical calibration were obtained for each of the six long bones, and separately for each sex and for the sexes combined, and also for the entire sample and when it is subdivided into two subsamples at the age of 2 years. Comparisons between inverse and classical calibration show there is a systematic bias in age estimations obtained from inverse calibration. In the classical calibration models, the length of the femur provides the most accurate estimates of age. Age estimates are more accurate for the male subsample and for individuals under the age of 2 years. These results and a test of previously published methods caution against inverse calibration as a technique for developing age estimation methods even from the immature skeleton. Age estimation methods developed using cemetery collections of identified human skeletons should not be uncritically applied to present-day populations from the same region since many populations have experienced dramatic secular trends in growth and adult height over the last century.

  17. Reduced diaphyseal strength associated with high intracortical vascular porosity within long bones of children with Osteogenesis Imperfecta

    PubMed Central

    Jameson, John; Smith, Peter; Harris, Gerald

    2015-01-01

    Osteogenesis Imperfecta is a genetic disorder resulting in bone fragility. The mechanisms behind this fragility are not well understood. In addition to characteristic bone mass deficiencies, research suggests that bone material properties are compromised in individuals with this disorder. However, little data exists regarding bone properties beyond the microstructural scale in individuals with this disorder. Specimens were obtained from long bone diaphyses of nine children with osteogenesis imperfecta during routine osteotomy procedures. Small rectangular beams, oriented longitudinally and transversely to the diaphyseal axis, were machined from these specimens and elastic modulus, yield strength, and maximum strength were measured in three-point bending. Intracortical vascular porosity, bone volume fraction, osteocyte lacuna density, and volumetric tissue mineral density were determined by synchrotron micro-computed tomography, and relationships among these mechanical properties and structural parameters were explored. Modulus and strength were on average 64–68% lower in the transverse vs. longitudinal beams (P<0.001, linear mixed model). Vascular porosity ranged between 3–42% of total bone volume. Longitudinal properties were associated negatively with porosity (P≤0.006, linear regressions). Mechanical properties, however, were not associated with osteocyte lacuna density or volumetric tissue mineral density (P≥0.167). Bone properties and structural parameters were not associated significantly with donor age (p≥0.225, linear mixed models). This study presents novel data regarding bone material strength in children with osteogenesis imperfecta. Results confirm that these properties are anisotropic. Elevated vascular porosity was observed in most specimens, and this parameter was associated with reduced bone material strength. These results offer insight towards understanding bone fragility and the role of intracortical porosity on the strength of bone

  18. Diaphyseal femoral fractures below the age of six years: Results of plaster application and long term followup

    PubMed Central

    Catena, Nunzio; Sénès, Filippo M; Riganti, Simone; Boero, Silvio

    2014-01-01

    Background: In children less than 6 years, the treatment of femoral shaft fracture is often non surgical, using closed reduction and casting. The literature reports many experience about this type of trauma but none of these has a long term followup. We present a retrospective study on a group of femoral diaphyseal fractures treated nonsurgically in children up to 6 years of age, with a minimum of 10 year followup. Materials and Methods: 48 cases (36 males/12 females) with femoral diaphyseal fractures treated between January 1988 and December 1998 were reviewed. Patients with fractures due to obstetrical trauma and pathologic fractures were excluded. The mean age of the patients was 3.3 ± 1.1 years (range 5 months-6 years). Right side was involved in 21 cases (44%), and left side in 27 cases (56%). In 34 cases (71%), closed reduction was performed and hip spica was applied with the hip and knee flexed to 45°. In 8 cases (17%), skeletal traction was applied to perform fracture reduction and the traction pin was embedded in plaster while in the remaining 6 cases (12%), the Delitala pressure apparatus was applied after casting. Results: All fractures healed in our study. There were no complications (infection or vascular nervous issues, axial deviations, consolidation delays, or pseudoarthrosis). In 13 cases (27%), followup examinations showed mean lengthening of 1.3 ± 0.75 (range 0.5-2.5 cm) of the fractured lower limb. All these patients were treated with skin traction before treatment and presented with 2.08 ± 0.28 cm mean initial femoral shortening. In 1 case (2%) with 2.5 cm lengthening, epiphysiodesis of the ipsilateral knee was performed. No patients showed prolonged difficulty with gait disorders. Conclusion: On the basis of our results conservative treatment of femoral shaft fractures in children can be considered less invasive and safe procedure. PMID:24600060

  19. Birth Defects

    MedlinePlus

    ... defects happen during the first 3 months of pregnancy. One out of every 33 babies in the ... abuse can cause fetal alcohol syndrome. Infections during pregnancy can also result in birth defects. For most ...

  20. Minimally Invasive Treatment of a Complex Tibial Plateau Fracture with Diaphyseal Extension in a Patient with Uncontrolled Diabetes Mellitus: A Case Report and Review of Literature

    PubMed Central

    Rathod, Ashok K; Pawaskar, Aditya

    2016-01-01

    Fractures of the proximal tibia comprise a huge spectrum of injuries with different fracture configurations. The combination of tibia plateau fracture with diaphyseal extension is a rare injury with sparse literature being available on treatment of the same. Various treatment modalities can be adopted with the aim of achieving a well-aligned, congruous, stable joint, which allows early motion and function. We report a case of a 40-year-old male who sustained a Schatzker type VI fracture of left tibial plateau with diaphyseal extension. On further investigations, the patient was diagnosed to have diabetes mellitus with grossly deranged blood sugar levels. The depressed tibial condyle was manipulated to lift its articular surface using K-wire as a joystick and stabilized with an additional K-wire. Distal tibial skeletal traction was maintained for three weeks followed by an above knee cast. At eight months of follow-up, X-rays revealed a well-consolidated fracture site, and the patient had attained a reasonably good range of motion with only terminal restriction of squatting. Tibial plateau fractures with diaphyseal extension in a patient with uncontrolled diabetes mellitus is certainly a challenging entity. After an extended search of literature, we could not find any reports highlighting a similar method of treatment for complex tibial plateau injuries in a patient with uncontrolled diabetes mellitus. PMID:27335711

  1. Minimally Invasive Treatment of a Complex Tibial Plateau Fracture with Diaphyseal Extension in a Patient with Uncontrolled Diabetes Mellitus: A Case Report and Review of Literature.

    PubMed

    Rathod, Ashok K; Dhake, Rakesh P; Pawaskar, Aditya

    2016-01-01

    Fractures of the proximal tibia comprise a huge spectrum of injuries with different fracture configurations. The combination of tibia plateau fracture with diaphyseal extension is a rare injury with sparse literature being available on treatment of the same. Various treatment modalities can be adopted with the aim of achieving a well-aligned, congruous, stable joint, which allows early motion and function. We report a case of a 40-year-old male who sustained a Schatzker type VI fracture of left tibial plateau with diaphyseal extension. On further investigations, the patient was diagnosed to have diabetes mellitus with grossly deranged blood sugar levels. The depressed tibial condyle was manipulated to lift its articular surface using K-wire as a joystick and stabilized with an additional K-wire. Distal tibial skeletal traction was maintained for three weeks followed by an above knee cast. At eight months of follow-up, X-rays revealed a well-consolidated fracture site, and the patient had attained a reasonably good range of motion with only terminal restriction of squatting. Tibial plateau fractures with diaphyseal extension in a patient with uncontrolled diabetes mellitus is certainly a challenging entity. After an extended search of literature, we could not find any reports highlighting a similar method of treatment for complex tibial plateau injuries in a patient with uncontrolled diabetes mellitus. PMID:27335711

  2. Behavior of bioactive glass-ceramic implanted into long bone defects: a scintigraphic study.

    PubMed

    Sponer, Pavel; Urban, Karel; Urbanová, Elen; Karpas, Karel; Mathew, Pradeep George

    2010-01-01

    The purpose of the study was to assess the long-term behavior and incorporation of the bioactive oxyhydroxyapatite glass-ceramic used to fill defects of long bones after curettage of bone cysts in 17 patients. The method of evaluation was a three-phase bone scintigraphy combined with radiographic and clinical evaluation. At a mean follow-up of 7 years, the glass-ceramic material had been completely incorporated. Mean uptake ratio was 1.31+/-0.25 after implantation of glass-ceramic in the metaphyseal region and 2.07+/-0.62 after implantation of glass-ceramic in the diaphyseal region (P<0.05). Mean uptake ratio was 1.40+/-0.30 in patients without persistent pain and 2.07+/-0.69 in patients who complained of pain in the area of synthetic filling (P<0.05). The bioactive glass-ceramic can be implanted into the metaphyseal defects of long bones, but this material is not suitable for filling the diaphyseal defects.

  3. Audit of open tibial diaphyseal fracture management at a district accident centre.

    PubMed

    Clough, T M; Bale, R S

    2000-11-01

    Preston Acute Hospital is a designated district accident centre with a 24 h flying squad and on-site plastic and orthopaedic units. We performed a retrospective 5-year survey of open tibial shaft fracture management at our unit and compared our treatment to the guidelines of the British Orthopaedic Association (BOA) and British Association of Plastic Surgeons (BAPS). Deficiencies were highlighted and changes in practice made. We then re-audited our figures over an 18-month period to see if clinical improvements had been made. The audit demonstrated an incidence of open tibial shaft fractures of 15 per 50,000 new patients per year in accident and emergency. Gustilo grading, and thus full appreciation of soft tissues injury, was being underestimated, with 8% of the injuries undergraded at the time of surgery: 17% of Gustilo IIIA and 85% Gustilo IIIB required flap cover. Seventy-four percent of patients received their first orthopaedic procedure within the recommended 6 h of admission, but despite the on-site plastics unit, only 50% of cases in the initial survey had their soft tissue defect covered by the recommended 5 days. After changes to practice, 80% patients received their first orthopaedic procedure within the recommended 6 h of admission, and all had their soft tissue defect covered within 5 days; 5% of cases required fasciotomy to relieve compartment syndrome. We highlight features to alert the high energy (Gustilo III) status and recommend immediate involvement of plastic surgical colleagues with these injuries. We also highlight a high incidence of compartment syndrome in the young male patient with the lower energy Gustilo I injury.

  4. Proximal diaphyseal fractures of the fifth metatarsal--treatment of the fractures and their complications in athletes.

    PubMed

    Zelko, R R; Torg, J S; Rachun, A

    1979-01-01

    Twenty-one patients (age range, 15 to 26; 18 patients 15 to 20 years old) had proximal diaphyseal fractures of the fifth metatarsal. Clinical records and radiographs for all patients were available for review. Patient treatment had been individualized and included several methods, including rest, plaster immobilization, and bone grafting. Twenty of the 21 patients were boys or men participating in athletics. Nine of the 21 fractures and 8 of the reinjuries were sustained while playing basketball. Healing required a minimum of 3 months (with bone graft) and some fractures were not radiographically healed at 20 months, although the patients were clinically asymptomatic. The fracture of the proximal shaft of the fifth metatarsal, particularly the 1.5-cm segment distal to the tuberosity, is a troublesome injury in the active athlete. The clinical course does not appear to be influenced by the usual initial conservative treatment modalities, although many of these fractures will heal if the athlete is willing to restrict activities for a prolonged period of time. In this series, bone grafting with a tibial corticocancellous graft after thorough curettage of sclerotic bone obliterating the medullary canal was the most effective treatment modality for delayed union.

  5. Combination of platelet-rich plasma with degradable bioactive borate glass for segmental bone defect repair.

    PubMed

    Zhang, Ya-Dong; Wang, Gang; Sun, Yan; Zhang, Chang-Qing

    2011-02-01

    Porous scaffold biomaterials may offer a clinical alternative to bone grafts; however, scaffolds alone are typically insufficient to heal large bone defects. Numerous studies have demonstrated that osteoinductive growth factor significantly improves bone repair. In this study, a strategy combining degradable bioactive borate glass (BG) scaffolds with platelet-rich plasma (PRP) was tested. The bone defect was filled with BG alone, BG combined with autologous PRP or left empty. Bone formation was analyzed at 4, 8 and 12 weeks using both histology and radiology. The PRP treated group yielded better bone formation than the pure BG scaffold as determined by both histology and microcomputer tomography after 12 weeks. In conclusion, PRP improved bone healing in a diaphyseal rabbit model on BG. The combination of PRP and BG may be an effective approach to repair critical defects.

  6. Long bone articular and diaphyseal structure in Old World monkeys and apes. II: Estimation of body mass.

    PubMed

    Ruff, Christopher B

    2003-01-01

    Body mass estimation equations are generated from long bone cross-sectional diaphyseal and articular surface dimensions in 176 individuals and 12 species of hominoids and cercopithecoids. A series of comparisons is carried out to determine the best body mass predictors for each of several taxonomic/locomotor groupings. Articular breadths are better predictors than articular surface areas, while cross-sectional shaft strengths are better predictors than shaft external breadths. Percent standard errors of estimate (%SEEs) and percent prediction errors for most of the better predictors range between 10-20%. Confidence intervals of equations using sex/species means are fairly representative of those calculated using individual data, except for sex/species means equations with very low %SEEs (under about 10%), where confidence intervals (CIs) based on individuals are likely to be larger. Given individual variability, or biological "error," this may represent a lower limit of precision in estimating individual body masses. In general, it is much more preferable to determine at least broad locomotor affinities, and thus appropriate modern reference groups, before applying body mass estimation equations. However, some structural dimensions are less sensitive to locomotor distinctions than others; for example, proximal tibial articular M-L breadth is apparently "locomotor blind" regarding body mass estimation within the present study sample. In other cases where locomotor affiliation is uncertain, mean estimates from different reference groups can be used, while for some dimensions no estimation should be attempted. The techniques are illustrated by estimating the body masses of four fossil anthropoid specimens of Proconsul nyanzae, Proconsul heseloni, Morotopithecus bishopi, and Theropithecus oswaldi.

  7. EVALUATION OF PATIENTS UNDERGOING FIXATION OF DIAPHYSEAL HUMERAL FRACTURES USING THE MINIMALLY INVASIVE BRIDGE-PLATE TECHNIQUE

    PubMed Central

    Superti, Mauro José; Martynetz, Fábio; Falavinha, Ricardo Sprenger; Fávaro, Rodrigo Caldonazzo; Boas, Luis Felipe Villas; Filho, Salim Mussi; Martynetz, Juliano; Ribas, Bruno

    2015-01-01

    Objective: The aim was to describe the experience of our group in treating humeral shaft fractures using the bridge–plate technique via an anterior approach. Methods: Seventeen patients with acute diaphyseal humeral fractures with an indication for surgical treatment who were operated in 2006–2010 were evaluated. The AO and Gustilo & Anderson classifications were used. All the patients were operated using the anterior bridge-plate technique and completed a follow–up period of at least twelve months. Results: Sixteen men and one woman were treated. Their mean age was 31.8 years (18–52). Among the injury mechanisms found were: five motorcycle accidents, four car accidents, three fractures due to firearm projectiles, two falls to the ground and finally, with one case each, assault, crushing and being run over. Eight patients had open fractures: two grade I, one grade II, four grade IIIa and one grade IIIb, according to the Gustilo-Anderson classification. In relation to the AO classification, we found: one 12A1, three 12A2, four 12A3, one 12B1, four 12 B2, three 12B3 and one 12C2. The mean postoperative follow-up was 25 months (12–48). As complications, two patients had pain in the elbow and a ROM deficit and one had deep infection. The mean time taken to achieve consolidation was 17.5 weeks. There was no loss of reduction, pseudarthrosis or malunion in this series of patients. Conclusion: The authors believe that the technique described has low rates of complications and morbidity, with good initial results, although the series is limited by the small sample. PMID:27042639

  8. Establishing biomechanical mechanisms in mouse models: practical guidelines for systematically evaluating phenotypic changes in the diaphyses of long bones.

    PubMed

    Jepsen, Karl J; Silva, Matthew J; Vashishth, Deepak; Guo, X Edward; van der Meulen, Marjolein C H

    2015-06-01

    Mice are widely used in studies of skeletal biology, and assessment of their bones by mechanical testing is a critical step when evaluating the functional effects of an experimental perturbation. For example, a gene knockout may target a pathway important in bone formation and result in a "low bone mass" phenotype. But how well does the skeleton bear functional loads; eg, how much do bones deform during loading and how resistant are bones to fracture? By systematic evaluation of bone morphological, densitometric, and mechanical properties, investigators can establish the "biomechanical mechanisms" whereby an experimental perturbation alters whole-bone mechanical function. The goal of this review is to clarify these biomechanical mechanisms and to make recommendations for systematically evaluating phenotypic changes in mouse bones, with a focus on long-bone diaphyses and cortical bone. Further, minimum reportable standards for testing conditions and outcome variables are suggested that will improve the comparison of data across studies. Basic biomechanical principles are reviewed, followed by a description of the cross-sectional morphological properties that best inform the net cellular effects of a given experimental perturbation and are most relevant to biomechanical function. Although morphology is critical, whole-bone mechanical properties can only be determined accurately by a mechanical test. The functional importance of stiffness, maximum load, postyield displacement, and work-to-fracture are reviewed. Because bone and body size are often strongly related, strategies to adjust whole-bone properties for body mass are detailed. Finally, a comprehensive framework is presented using real data, and several examples from the literature are reviewed to illustrate how to synthesize morphological, tissue-level, and whole-bone mechanical properties of mouse long bones. PMID:25917136

  9. Establishing Biomechanical Mechanisms in Mouse Models: Practical Guidelines for Systematically Evaluating Phenotypic Changes in the Diaphyses of Long Bones

    PubMed Central

    Jepsen, Karl J; Silva, Matthew J; Vashishth, Deepak; Guo, X Edward; van der Meulen, Marjolein CH

    2016-01-01

    Mice are widely used in studies of skeletal biology, and assessment of their bones by mechanical testing is a critical step when evaluating the functional effects of an experimental perturbation. For example, a gene knockout may target a pathway important in bone formation and result in a “low bone mass” phenotype. But how well does the skeleton bear functional loads; eg, how much do bones deform during loading and how resistant are bones to fracture? By systematic evaluation of bone morphological, densitometric, and mechanical properties, investigators can establish the “biomechanical mechanisms” whereby an experimental perturbation alters whole-bone mechanical function. The goal of this review is to clarify these biomechanical mechanisms and to make recommendations for systematically evaluating phenotypic changes in mouse bones, with a focus on long-bone diaphyses and cortical bone. Further, minimum reportable standards for testing conditions and outcome variables are suggested that will improve the comparison of data across studies. Basic biomechanical principles are reviewed, followed by a description of the cross-sectional morphological properties that best inform the net cellular effects of a given experimental perturbation and are most relevant to biomechanical function. Although morphology is critical, whole-bone mechanical properties can only be determined accurately by a mechanical test. The functional importance of stiffness, maximum load, postyield displacement, and work-to-fracture are reviewed. Because bone and body size are often strongly related, strategies to adjust whole-bone properties for body mass are detailed. Finally, a comprehensive framework is presented using real data, and several examples from the literature are reviewed to illustrate how to synthesize morphological, tissue-level, and whole-bone mechanical properties of mouse long bones. PMID:25917136

  10. Ovine Model for Critical-Size Tibial Segmental Defects

    PubMed Central

    Christou, Chris; Oliver, Rema A; Pelletier, Matthew H; Walsh, William R

    2014-01-01

    A segmental tibial defect model in a large animal can provide a basis for testing materials and techniques for use in nonunions and severe trauma. This study reports the rationale behind establishing such a model and its design and conclusions. After ethics approval of the study, aged ewes (older than 5 y; n = 12) were enrolled. A 5-cm mid diaphyseal osteoperiosteal defect was made in the left tibia and was stabilized by using an 8-mm stainless-steel cross-locked intramedullary nail. Sheep were euthanized at 12 wk after surgery and evaluated by using radiography, microCT, and soft-tissue histology techniques. Radiology confirmed a lack of hard tissue callus bridging across the defect. Volumetric analysis based on microCT showed bone growth across the 16.5-cm3 defect of 1.82 ± 0.94 cm3. Histologic sections of the bridging tissues revealed callus originating from both the periosteal and endosteal surfaces, with fibrous tissue completing the bridging in all instances. Immunohistochemistry was used to evaluate the quality of the healing response. Clinical, radiographic, and histologic union was not achieved by 12 wk. This model may be effective for the investigation of surgical techniques and healing adjuncts for nonunion cases, where severe traumatic injury has led to significant bone loss. PMID:25402178

  11. 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…

  12. Diaphyseal lengthening for brachymetatarsia.

    PubMed

    Nuzzo, J J; Mueller, R A

    1987-01-01

    The authors present a case report of brachymetatarsia. The literature is reviewed, various surgical treatments are discussed, and the preferred surgical procedure that relieved symptoms and achieved cosmetic approval is described. PMID:3655202

  13. The effect of platelet-rich plasma on healing in critical-size long-bone defects.

    PubMed

    Kasten, Philip; Vogel, Julia; Geiger, Florian; Niemeyer, Philipp; Luginbühl, Reto; Szalay, Krisztian

    2008-10-01

    The role of platelet-rich plasma (PRP) as a promoter of bone healing remains controversial. The hypothesis investigated was that PRP improves bone healing of a critical-size diaphyseal radius defect in a rabbit model. The bone defect was filled with a high-surface ceramic scaffold, calcium-deficient hydroxyapatite (CDHA), with the addition of allogenic PRP, mesenchymal stem cells (MSC) or both. PRP yielded better bone formation than the empty CDHA scaffold as determined by both histology and micro-computer tomography (p<0.05) after 16 weeks, whereas no difference was observed on biomechanical testing. Similar behavior was found in samples with MSC; however, the combination of MSC and PRP did not further improve bone healing. Furthermore, the resorption of CDHA was improved by the addition of PRP, MSC and MSC/PRP, but there were no differences between the groups. The areas of bone formation were greater in areas adjacent to the bone resection areas and towards the intact ulna. In conclusion, PRP improves bone healing in a diaphyseal rabbit model on CDHA and the combination of CDHA. This study supports the allogenic use of PRP for bone healing as an off-the-shelf therapy.

  14. Positron Annihilation Studies of Defects in Silicon

    NASA Astrophysics Data System (ADS)

    Simpson, Peter J.

    Measurements of Doppler-broadening of annihilation radiation from variable-energy positrons have been applied to examine the nature and distribution of defects in ion -irradiated silicon. Positron measurements were supplemented by ion backscattering/channeling to determine displaced atom distributions, and infrared absorption measurements to determine divacancy concentrations. Silicon (100) wafers were irradiated at 300K with helium ions at energies from 0.25 to 4.0 MeV and fluences from 10^{13 } to 10^{16} cm^{-2}, and with silicon ions at energies from 0.5 to 5.0 MeV and fluences from 10^{11} to 10 ^{15} cm^{ -2}. Defect annealing was observed through the divacancy annealing stage (~470 to 570K). He-irradiated silicon was restored toward single crystal quality as measured by both infrared and positron methods. For the same anneal, Si-irradiated silicon shows partial restoration of crystallinity (RBS), and removal of the optically-active divacancies, but no change in positron trapping characteristics. Annealing to between 870 and 970K restores the crystal to near pre-implant characteristics. Results are discussed in terms of existing models of damage production during ion irradiation. Variable-energy positron methods have also been applied to study silicon layers grown by molecular beam epitaxy at low temperatures. The epilayers contain voids of ~6 mm diameter, which constitute efficient positron traps. The densities and sizes of voids in the epilayers were determined by transmission electron microscopy. Extremely narrow positron annihilation lineshapes were measured, and attributed to the formation of positronium within the voids. Measurements of the fraction of positrons trapped by voids are compared with the predictions of diffusion -limited trapping theory. The scope and limitations of defect profiling with variable-energy positrons and suggestions for further development of the technique are discussed.

  15. Ventricular septal defect (image)

    MedlinePlus

    Ventricular septal defect is a congenital defect of the heart, that occurs as an abnormal opening in ... wall that separates the right and left ventricles. Ventricular septal defect may also be associated with other ...

  16. Neural Tube Defects

    MedlinePlus

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

  17. Effect of the defectiveness of semiconductor on the characteristics of Pd-GaAs contacts

    SciTech Connect

    Parkhomenko, R.P.; Glushchenko, V.A.; Yakubenya, M.P.; Grigor'ev, Yu.A.; Potrepalov, A.A.

    1989-01-01

    A study was made of the volt-ampere characteristics of Pd-GaAs Schottky barriers in relation to the defectiveness of the gallium arsenide. The defect content of the material was checked metallographically and by the method of x-ray topography. Single crystals of GaAs doped with Ge, Ge + Sb, and Ge + In were studied. Here, the electron concentration was (1-4) /times/ 10/sup 16/ cm/sup /minus/3/, and mean dislocation density ranged from 4 /times/ 10/sup 4/ to 2 /times/ 10/sup 2/ cm/sup /minus/2/. The defectiveness of the material was altered by the introduction of different concentrations of isovalent impurities. It was shown that for diodes produced by the same technology, the manifestation of low-temperature VAC anomalies and the current mechanism are determined by structural features of the semiconductor (by dislocations and microdefects).

  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. Duralumin - Defects and Failures

    NASA Technical Reports Server (NTRS)

    Nelson, WM

    1927-01-01

    It is proposed in this paper to identify some of the defects and failures in duralumin most frequently encountered by the aircraft industry with a view to indicate their importance. The defects and failures in duralumin may be classified into the following groups: 1) defects produced during manufacture; 2) defects produced during fabrication; 3) corrosion and erosion; and 4) fatigue failures. Only the first two will be covered in this report.

  20. Influence of radiation defects on electrical losses in silicon diodes irradiated with electrons

    SciTech Connect

    Poklonski, N. A. Gorbachuk, N. I.; Shpakovski, S. V.; Lastovskii, S. B.; Wieck, A.

    2010-03-15

    Silicon diodes with a p{sup +}-n junction irradiated with 3.5-MeV electrons (the fluence ranged from 10{sup 15} to 4 x 10{sup 16} cm{sup -2}) have been studied. It is established that the dependence of the tangent of the angle of electrical losses tan{delta} on the frequency f of alternating current in the range f = 10{sup 2}-10{sup 6} Hz is a nonmonotonic function with two extrema: a minimum and a maximum. Transformation of the dependences tan{delta}(f) as the electron fluence and annealing temperature are increased is caused by a variation in the resistance of n-Si (the base region of the diodes) as a result of accumulation (as the fluence is increased) or disappearance and reconfiguration (in the course of annealing) of radiation defects. The role of time lag of the defect recharging in the formation of tan{delta}(f) is insignificant.

  1. 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 ...

  2. 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.

  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. Biomimetic tubular nanofiber mesh and platelet rich plasma-mediated delivery of BMP-7 for large bone defect regeneration.

    PubMed

    Berner, A; Boerckel, J D; Saifzadeh, S; Steck, R; Ren, J; Vaquette, C; Zhang, J Qiyi; Nerlich, M; Guldberg, R E; Hutmacher, D W; Woodruff, M A

    2012-03-01

    There is a growing need for successful bone tissue engineering strategies and advanced biomaterials that mimic the structure and function of native tissues carry great promise. Successful bone repair approaches may include an osteoconductive scaffold, osteoinductive growth factors, cells with an osteogenic potential and capacity for graft vascularisation. To increase osteoinductivity of biomaterials, the local combination and delivery of growth factors has been developed. In the present study we investigated the osteogenic effects of calcium phosphate (CaP)-coated nanofiber mesh tube-mediated delivery of BMP-7 from a PRP matrix for the regeneration of critical sized segmental bone defects in a small animal model. Bilateral full-thickness diaphyseal segmental defects were created in twelve male Lewis rats and nanofiber mesh tubes were placed around the defect. Defects received either treatment with a CaP-coated nanofiber mesh tube (n = 6), an un-coated nanofiber mesh tube (n=6) a CaP-coated nanofiber mesh tube with PRP (n=6) or a CaP-coated nanofiber mesh tube in combination with 5 μg BMP-7 and PRP (n = 6). After 12 weeks, bone volume and biomechanical properties were evaluated using radiography, microCT, biomechanical testing and histology. The results demonstrated significantly higher biomechanical properties and bone volume for the BMP group compared to the control groups. These results were supported by the histological evaluations, where BMP group showed the highest rate of bone regeneration within the defect. In conclusion, BMP-7 delivery via PRP enhanced functional bone defect regeneration, and together these data support the use of BMP-7 in the treatment of critical sized defects.

  5. Histopathological features of bone regeneration in a canine segmental ulnar defect model

    PubMed Central

    2014-01-01

    Background Today, finding an ideal biomaterial to treat the large bone defects, delayed unions and non-unions remains a challenge for orthopaedic surgeions and researchers. Several studies have been carried out on the subject of bone regeneration, each having its own advantages. The present study has been designed in vivo to evaluate the effects of cellular auto-transplantation of tail vertebrae on healing of experimental critical bone defect in a dog model. Methods Six indigenous breeds of dog with 32 ± 3.6 kg average weight from both sexes (5 males and 1 female) received bilateral critical-sized ulnar segmental defects. After determining the health condition, divided to 2 groups: The Group I were kept as control I (n = 1) while in Group II (experimental group; n = 5) bioactive bone implants were inserted. The defects were implanted with either autogeneic coccygeal bone grafts in dogs with 3-4 cm diaphyseal defects in the ulna. Defects were stabilized with internal plate fixation, and the control defects were not stabilized. Animals were euthanized at 16 weeks and analyzed by histopathology. Results Histological evaluation of this new bone at sixteen weeks postoperatively revealed primarily lamellar bone, with the formation of new cortices and normal-appearing marrow elements. And also reformation cortical compartment and reconstitution of marrow space were observed at the graft-host interface together with graft resorption and necrosis responses. Finally, our data were consistent with the osteoconducting function of the tail autograft. Conclusions Our results suggested that the tail vertebrae autograft seemed to be a new source of autogenous cortical bone in order to supporting segmental long bone defects in dogs. Furthermore, cellular autotransplantation was found to be a successful replacement for the tail vertebrae allograft bone at 3-4 cm segmental defects in the canine mid- ulna. Clinical application using graft expanders or bone

  6. ASASSN-16cm: Discovery of A Probable Supernova in 2MASX J15192684-0055256

    NASA Astrophysics Data System (ADS)

    Brown, J. S.; Monard, L. A. G.; Dong, Subo; Holoien, T. W.-S.; Stanek, K. Z.; Kochanek, C. S.; Godoy-Rivera, D.; Basu, U.; Shappee, B. J.; Prieto, J. L.; Bersier, D.; Chen, Ping; Brimacombe, J.; Bock, G.; Conseil, E.; Fernandez, J. M.; Kiyota, S.; Masi, G.; Wiethoff, W.

    2016-03-01

    During the ongoing All Sky Automated Survey for SuperNovae (ASAS-SN or "Assassin"), using data from the quadruple 14-cm "Cassius" telescope in Cerro Tololo, Chile, we discovered a new transient source, most likely a supernova, in the galaxy 2MASX J15192684-0055256.

  7. 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.

  8. Micrograph Defect Indentifier

    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

  9. 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.

  10. Surface defects and symmetries

    NASA Astrophysics Data System (ADS)

    Fuchs, Jürgen; Schweigert, Christoph

    2015-04-01

    In quantum field theory, defects of various codimensions are natural ingredients and carry a lot of interesting information. In this contribution we concentrate on topological quantum field theories in three dimensions, with a particular focus on Dijkgraaf-Witten theories with abelian gauge group. Surface defects in Dijkgraaf-Witten theories have applications in solid state physics, topological quantum computing and conformal field theory. We explain that symmetries in these topological field theories are naturally defined in terms of invertible topological surface defects and are thus Brauer-Picard groups.

  11. 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

  12. 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 ...

  13. 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 ...

  14. Anatomic uterine defects.

    PubMed

    Patton, P E

    1994-09-01

    Congenital or acquired uterine defects remain important considerations in the investigation of recurrent pregnancy loss. When repeated first or second trimester losses, preterm delivery, or abnormal fetal presentations are documented, the suspicion of a structural uterine abnormality should be high. The diagnosis of uterine defects is no longer elusive. The combination of radiologic imaging techniques, hysteroscopy, and laparoscopy enables an accurate diagnosis in nearly every case. The optimal treatment for uterine malformations is still a matter of considerable controversy. Therefore, when a uterine defect is diagnosed, tough clinical decisions must be made. When alternate causes of pregnancy loss are excluded, pregnancy potential will depend primarily on the specific type of uterine anomaly that is detected. It is important to recognize that not all uterine defects are amenable to therapy, but in carefully selected patients, reparative surgery may be rewarding.

  15. Automated Defect Classification (ADC)

    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

  16. 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.

  17. 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 ...

  18. 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

  19. Congenital platelet function defects

    MedlinePlus

    Platelet storage pool disorder; Glanzmann's thrombasthenia; Bernard-Soulier syndrome; Platelet function defects - congenital ... disorder may also cause severe bleeding. Platelet storage pool disorder (also called platelet secretion disorder) occurs when ...

  20. Automated Defect Classification (ADC)

    SciTech Connect

    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 wafer 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.

  1. Tyrosine-derived polycarbonate scaffolds for bone regeneration in a rabbit radius critical-size defect model.

    PubMed

    Kim, Jinku; McBride, Sean; Donovan, Amy; Darr, Aniq; Magno, Maria Hanshella R; Hollinger, Jeffrey O

    2015-06-01

    The aim of the study was to determine bone regeneration in a rabbit radius critical-size defect (CSD) model using a specific polymer composition (E1001(1k)) from a library of tyrosine-derived polycarbonate scaffolds coated with a calcium phosphate (CP) formulation (E1001(1k) + CP) supplemented with recombinant human bone morphogenetic protein-2 (rhBMP-2). Specific doses of rhBMP-2 (0, 17, and 35 μg/scaffold) were used. E1001(1k) + CP scaffolds were implanted in unilateral segmental defects (15 mm length) in the radial diaphyses of New Zealand White rabbits. At 4 and 8 weeks post-implantation, bone regeneration was determined using micro-computed tomography (µCT), histology, and histomorphometry. The quantitative outcome data suggest that E1001(1k) + CP scaffolds with rhBMP-2 were biocompatible and promoted bone regeneration in segmental bone defects. Histological examination of the implant sites showed that scaffolds made of E1001(1k) + CP did not elicit adverse cellular or tissue responses throughout test periods up to 8 weeks. Noteworthy is that the incorporation of a very small amount of rhBMP-2 into the scaffolds (as low as 17 μg/defect site) promoted significant bone regeneration compared to scaffolds consisting of E1001(1k) + CP alone. This finding indicates that E1001(1k) + CP may be an effective platform for bone regeneration in a critical size rabbit radius segmental defect model, requiring only a minimal dose of rhBMP-2.

  2. 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…

  3. 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.

  4. 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

  5. Calvarial defect reconstruction.

    PubMed

    Jimenez, D F; Barone, C M

    1994-04-01

    The history of skull trepanation is almost as old as that of humanity. For thousands of years it has been performed for the treatment of numerous medical maladies. The Andean Incas, early Asians and South Seas Islanders, are amongst the many people to perform calvarial trepanation. Hippocrates described techniques for the use of the trepan in early Greek times. With the production of a skull opening comes the challenge of developing methods for closing the defect. It is in reality, more challenging to repair the defect than to create it. Man, with his never ending ingenuity, has tried to develop many techniques. We will discuss some of them and present our method of choice for closure of skull defects.

  6. 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.

  7. Fast diffusion along defects and corrugations in phospholipid P beta, liquid crystals.

    PubMed Central

    Schneider, M B; Chan, W K; Webb, W W

    1983-01-01

    The diffusion of a fluorescent lipid analogue in liquid crystals of the anisotropic P beta, phase of dimyristoylphosphatidylcholine (DMPC) had been found to be highly variable, suggesting structural defect pathways. Fluorescence photobleaching recovery (FPR) experiments imply two effective diffusion pathways with coefficients differing by at least 100. This is consistent with fast diffusion along submicroscopic bands of disordered material ("defects") in the bilayer corrugations characteristic of this phase. Due to strains during transformation from the L alpha phase, the axis of the corrugations is ordinarily disrupted by mosaic patches rotationally disoriented within the mean plane of the molecular bilayers, although larger oriented domains are sometimes adventitiously aligned into microscopically visible striped textures. The corrugations are also systematically aligned along positive disclinations pairs or "oily streaks." Thus, fast diffusion occurs parallel to the disclination lines and along the textured stripes. FPR results yield an upper limit on the effective diffusion in the ordered material of D less than or equal to 2 X 10(-16) cm2/s at 22 degrees C, D less than or equal to 3 X 10(-17) cm2/s at 13 degrees C. In contrast the diffusion coefficient along defect pathways where disordered ribbons are aligned is D approximately 4 X 10(-11) cm2/s at 16 degrees C. Images FIGURE 4 FIGURE 6 FIGURE 7 PMID:6616004

  8. 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.

  9. 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.

  10. Quantum computing with defects

    PubMed Central

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

    2010-01-01

    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

  11. 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 ...

  12. 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 & ...

  13. 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: ...

  14. 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 ...

  15. 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) ...

  16. 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 ...

  17. 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

  18. Molecular defects in the chondrodysplasias

    SciTech Connect

    Rimoin, D.L.

    1996-05-03

    There has been a recent explosion of knowledge concerning the biochemical and molecular defects in the skeletal dysplasia. Through both the candidate gene approach and positional cloning, specific gene defects that produce the skeletal dysplasia have been identified and may be classified into several general categories: (1) qualitative or quantitative abnormalities in the structural proteins of cartilage; (2) inborn errors of cartilage metabolism; (3) defects in local regulators of cartilage growth; and (4) systemic defects influencing cartilage development. 35 refs., 1 tab.

  19. 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

  20. 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.

  1. 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.

  2. Defect modes of chiral photonic crystals with an isotropic defect

    NASA Astrophysics Data System (ADS)

    Gevorgyan, A. H.; Oganesyan, K. B.

    2011-06-01

    Specific features of the defect modes of cholesteric liquid crystals (CLCs) with an isotropic defect, as well as their photonic density of states, Q factor, and emission, have been investigated. The effect of the thicknesses of the defect layer and the system as a whole, the position of the defect layer, and the dielectric boundaries on the features of the defect modes have been analyzed. It is shown that when the CLC layer is thin the density of states and emission intensity are maximum for the defect mode, whereas when the CLC layer is thick, these peaks are observed at the edges of the photonic band gap. Similarly, when the gain is low, the density of states and emission intensity are maximum for the defect mode, whereas at high gains these peaks are also observed at the edges of the photonic band gap. The possibilities of low-threshold lasing and obtaining high- Q microcavities have been investigated.

  3. Invisible defects in complex crystals

    SciTech Connect

    Longhi, Stefano Della Valle, Giuseppe

    2013-07-15

    We show that invisible localized defects, i.e. defects that cannot be detected by an outside observer, can be realized in a crystal with an engineered imaginary potential at the defect site. The invisible defects are synthesized by means of supersymmetric (Darboux) transformations of an ordinary crystal using band-edge wavefunctions to construct the superpotential. The complex crystal has an entire real-valued energy spectrum and Bragg scattering is not influenced by the defects. An example of complex crystal synthesis is presented for the Mathieu potential. -- Highlights: •We show the existence of invisible localized defects in complex crystals. •They turn out to be fully invisible to Bloch waves belonging to any lattice band. •An example of invisible defect is presented for a PT-symmetric Mathieu crystal.

  4. Multiscale, converging defects of macro-porosity, microstructure and matrix mineralization impact long bone fragility in NF1.

    PubMed

    Kühnisch, Jirko; Seto, Jong; Lange, Claudia; Schrof, Susanne; Stumpp, Sabine; Kobus, Karolina; Grohmann, Julia; Kossler, Nadine; Varga, Peter; Osswald, Monika; Emmerich, Denise; Tinschert, Sigrid; Thielemann, Falk; Duda, Georg; Seifert, Wenke; El Khassawna, Thaqif; Stevenson, David A; Elefteriou, Florent; Kornak, Uwe; Raum, Kay; Fratzl, Peter; Mundlos, Stefan; Kolanczyk, Mateusz

    2014-01-01

    Bone fragility due to osteopenia, osteoporosis or debilitating focal skeletal dysplasias is a frequent observation in the Mendelian disease Neurofibromatosis type 1 (NF1). To determine the mechanisms underlying bone fragility in NF1 we analyzed two conditional mouse models, Nf1Prx1 (limb knock-out) and Nf1Col1 (osteoblast specific knock-out), as well as cortical bone samples from individuals with NF1. We examined mouse bone tissue with micro-computed tomography, qualitative and quantitative histology, mechanical tensile analysis, small-angle X-ray scattering (SAXS), energy dispersive X-ray spectroscopy (EDX), and scanning acoustic microscopy (SAM). In cortical bone of Nf1Prx1 mice we detected ectopic blood vessels that were associated with diaphyseal mineralization defects. Defective mineral binding in the proximity of blood vessels was most likely due to impaired bone collagen formation, as these areas were completely devoid of acidic matrix proteins and contained thin collagen fibers. Additionally, we found significantly reduced mechanical strength of the bone material, which was partially caused by increased osteocyte volume. Consistent with these observations, bone samples from individuals with NF1 and tibial dysplasia showed increased osteocyte lacuna volume. Reduced mechanical properties were associated with diminished matrix stiffness, as determined by SAM. In line with these observations, bone tissue from individuals with NF1 and tibial dysplasia showed heterogeneous mineralization and reduced collagen fiber thickness and packaging. Collectively, the data indicate that bone fragility in NF1 tibial dysplasia is partly due to an increased osteocyte-related micro-porosity, hypomineralization, a generalized defect of organic matrix formation, exacerbated in the regions of tensional and bending force integration, and finally persistence of ectopic blood vessels associated with localized macro-porotic bone lesions.

  5. Multiscale, Converging Defects of Macro-Porosity, Microstructure and Matrix Mineralization Impact Long Bone Fragility in NF1

    PubMed Central

    Kühnisch, Jirko; Seto, Jong; Lange, Claudia; Schrof, Susanne; Stumpp, Sabine; Kobus, Karolina; Grohmann, Julia; Kossler, Nadine; Varga, Peter; Osswald, Monika; Emmerich, Denise; Tinschert, Sigrid; Thielemann, Falk; Duda, Georg; Seifert, Wenke; el Khassawna, Thaqif; Stevenson, David A.; Elefteriou, Florent; Kornak, Uwe; Raum, Kay; Fratzl, Peter; Mundlos, Stefan; Kolanczyk, Mateusz

    2014-01-01

    Bone fragility due to osteopenia, osteoporosis or debilitating focal skeletal dysplasias is a frequent observation in the Mendelian disease Neurofibromatosis type 1 (NF1). To determine the mechanisms underlying bone fragility in NF1 we analyzed two conditional mouse models, Nf1Prx1 (limb knock-out) and Nf1Col1 (osteoblast specific knock-out), as well as cortical bone samples from individuals with NF1. We examined mouse bone tissue with micro-computed tomography, qualitative and quantitative histology, mechanical tensile analysis, small-angle X-ray scattering (SAXS), energy dispersive X-ray spectroscopy (EDX), and scanning acoustic microscopy (SAM). In cortical bone of Nf1Prx1 mice we detected ectopic blood vessels that were associated with diaphyseal mineralization defects. Defective mineral binding in the proximity of blood vessels was most likely due to impaired bone collagen formation, as these areas were completely devoid of acidic matrix proteins and contained thin collagen fibers. Additionally, we found significantly reduced mechanical strength of the bone material, which was partially caused by increased osteocyte volume. Consistent with these observations, bone samples from individuals with NF1 and tibial dysplasia showed increased osteocyte lacuna volume. Reduced mechanical properties were associated with diminished matrix stiffness, as determined by SAM. In line with these observations, bone tissue from individuals with NF1 and tibial dysplasia showed heterogeneous mineralization and reduced collagen fiber thickness and packaging. Collectively, the data indicate that bone fragility in NF1 tibial dysplasia is partly due to an increased osteocyte-related micro-porosity, hypomineralization, a generalized defect of organic matrix formation, exacerbated in the regions of tensional and bending force integration, and finally persistence of ectopic blood vessels associated with localized macro-porotic bone lesions. PMID:24465906

  6. 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.

  7. HDL genetic defects.

    PubMed

    Nair, Devaki R; Nair, Arun; Jain, Anjly

    2014-01-01

    High density lipoprotein cholesterol (HDL-C) and its related apolipoproteins form part of the reverse cholesterol transport system that removes excessive cholesterol from the periphery to the liver. Many transport proteins and enzymes that are involved in this process are susceptible to genetic defects that influence plasma HDL-C concentrations and HDL function. The HDL-C concentration in the blood may not be as important as the function of this lipid fraction. The genetic defects affecting plasma HDL-C concentrations do not always show a consistent relationship with atherosclerosis. Familial hypoalphalipoproteinaemia is associated with mutations in genes responsible for the transport proteins or the enzymes involved in the biogenesis of HDL-C. Inheritance of a Milano mutation of apolipoprotein A1 decreases the risk of atherosclerotic disease despite low circulating levels of HDL-C. Tangier disease and Fish Eye disease are caused by mutations in the ATP binding cassette A1 (ABCA1), a transport protein, and lecithin cholesterol acyl transferase (LCAT), an enzyme, involved in the esterification of cholesterol, respectively. Patients with these conditions have very low levels of HDL-C concentration. The association between both these conditions and the risk of cardiovascular disease (CVD) is variable and inconsistent. Understanding the molecular mechanism of HDL biogenesis not only helped in defining the pathophysiology of low and high HDL-C syndromes, but also in developing new treatment options to raise HDL-C levels. PMID:24953397

  8. Enhanced healing of segmental tibial defects in sheep by a composite bone substitute composed of tricalcium phosphate cylinder, bone morphogenetic protein, and type IV collagen.

    PubMed

    Gao, T J; Lindholm, T S; Kommonen, B; Ragni, P; Paronzini, A; Lindholm, T C; Jämsä, T; Jalovaara, P

    1996-12-01

    Diaphyseal segmental defects in the tibia of 18 sheep were used to evaluate the healing potential of a composite bone substitute device (CBS) composed of a tricalcium phosphate cylinder (TCP), naturally occurring sheep bone morphogenetic protein (sBMP), and type IV collagen. A total of 100 mg of sBMP and 20 mg of type IV collagen in the high-dose group (CBSH), and 13 mg of sBMP and 2.5 mg of type IV collagen in the low-dose group (CBSL) were adsorbed to TCP cylinders, respectively. TCP cylinders impregnated with type IV collagen alone (TCPC) were used as control. A significantly larger area and more highly integrated intensity of newly formed external callus between CBSH and CBSL or TCPC group were quantified by computerized image analyzer at both 3 and 6 weeks. A torsion test showed that the maximal torque capacity, maximal angular deformation, and bone stiffness of healed osteotomized tibia with implants recovered 117-125% in CBSH, 72-109% in CBSL, and 63-80% in TCPC, compared with the corresponding contralateral tibia at 16 weeks. A healing superiority of the segmental bone defects replaced by the implants was demonstrated in the CBSH group. Thus, the composite bone substitute device defined in this study was shown to possess osteoinductivity, osteoconductivity, and mechanical strength.

  9. 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.

  10. Genetics of Atrial Septal Defect

    PubMed Central

    Cascos, Andrés Sánchez

    1972-01-01

    Of 109 cases of atrial septal defect, cases with an isolated defect (92 cases) showed a female preponderance (sex ratio 0·64), but there was a higher risk to the sibs of the male patients, suggesting a multifactorial mechanism. Dermatoglyphs showed a large number of whorls on the fingers. In 17 cases there were multiple malformations, such as Holt-Oram syndrome (hypoplastic and triphalangic thumb, with ostium secundum atrial septal defect), polydactyly plus ostium primum defect, and tracheo-oesophageal fistula. ImagesFIG. 1.FIG. 2.FIG. 3. PMID:4261647

  11. 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

  12. 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 ...

  13. 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.

  14. 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.

  15. 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.

  16. Holographic Chern-Simons defects

    DOE PAGES

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

    2016-06-28

    Here, 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 themore » defects as well as the temperature are varied. We also discuss some implications for the Fractional Quantum Hall Effect and for 2-dimensional QCD.« less

  17. Mask defect verification using actinic inspection and defect mitigation technology

    SciTech Connect

    Huh, Sungmin; Kearney, Patrick; Wurm, Stefan; Goodwin, Frank; Goldberg, Kenneth; Mochi, Iacopo; Gullikson, Eric

    2009-04-14

    The availability of defect-free masks remains one of the key challenges for inserting extreme ultraviolet lithography (EUVL) into high volume manufacturing. The successful production of defect-free masks will depend on the timely development of defect inspection tools, including both mask blank inspection tools and absorber pattern inspection tools to meet the 22 nm half-pitch node. EUV mask blanks with embedded phase defects were inspected with a reticle actinic inspection tool (AIT) and the Lasertec M7360. The Lasertec M7360 is operated at SEMA TECH's Mask blank Development Center (MBDC) in Albany, with 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 the next generation blank inspection tool to support reticle development for the sub-32 nm half-pitch technology node. This paper will also discuss the kind of infrastructure that will be required in the development and mass production stages.

  18. Neural tube defects.

    PubMed

    Hasenau, Susan M; Covington, Chandice

    2002-01-01

    The purpose of this article is to describe the etiology of neural tube defects (NTDs) and the role of folic acid in their prevention. NTDs are all too common and devastating outcomes of many pregnancies. The brain and spinal cord malformations that develop during gestation in the NTD-affected pregnancies are expressed through various anomalies. Estimates by the Centers for Disease Control and Prevention (CDC) for 1995 reported over 4,000 occurrences of NTDs in the United States alone. Research has demonstrated that the preconception and prenatal addition of folic acid can greatly reduce the incidence of NTDs. Recent advances in genetic studies have increased awareness of the important role of folic acid in preventing NTDs. Identification of a genetic marker will allow for specific treatment of those women at high risk for NTDs. Despite recommendations from the CDC for folic acid supplementation, there is insufficient awareness of these guidelines by both the public and by healthcare providers. A National campaign to promote awareness of the role of folic acid in the prevention of NTDs has been initiated, and has been successful at reducing NTDs's by 19%. Nurses can be instrumental in the dissemination of information not only to women of childbearing age, but also to other nurses and physicians. PMID:11984276

  19. 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

  20. 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.

  1. 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.

  2. 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

  3. Biomaterials in periodontal osseous defects

    PubMed Central

    Lal, Nand; Dixit, Jaya

    2012-01-01

    Introduction Osseous defects in periodontal diseases require osseous grafts and guided tissue regeneration (GTR) using barrier membranes. The present study was undertaken with the objectives to clinically evaluate the osteogenic potential of hydroxyapatite (HA), cissus quadrangularis (CQ), and oxidized cellulose membrane (OCM) and compare with normal bone healing. Materials and Methods Twenty subjects with periodontitis in the age group ranging from 20 years to 40 years were selected from our outpatient department on the basis of presence of deep periodontal pockets, clinical probing depth ≥5 mm, vertical osseous defects obvious on radiograph and two- or three-walled involvement seen on surgical exposure. Infrabony defects were randomly divided into four groups on the basis of treatment to be executed, such that each group comprised 5 defects. Group I was control, II received HA, III received CQ and IV received OCM. Probing depth and attachment level were measured at regular months after surgery. Defects were re-exposed using crevicular incisions at 6 months. Results There was gradual reduction in the mean probing pocket depth in all groups, but highly significant in the site treated with HA. Gain in attachment level was higher in sites treated with HA, 3.2 mm at 6 months. Conclusion Hydroxyapatite and OCM showed good reduction in pocket depth, attachment level gain and osseous defect fill. Further study should be conducted by using a combination of HA and OCM in periodontal osseous defects with growth factors and stem cells. PMID:25756030

  4. 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.

  5. 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

  6. 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: ...

  7. 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.

  8. 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. ...

  9. The suitability of an uncemented hydroxyapatite coated (HAC) hip hemiarthroplasty stem for intra-capsular femoral neck fractures in osteoporotic elderly patients: the Metaphyseal-Diaphyseal Index, a solution to preventing intra-operative periprosthetic fracture.

    PubMed

    Chana, Rishi; Mansouri, Reza; Jack, Chris; Edwards, Max R; Singh, Ravi; Keller, Carmel; Khan, Farid

    2011-11-18

    This study will seek to identify a measurable radiographic index, the Metaphyseal-Diaphyseal Index (MDI) score to determine whether intra-operative fracture in osteoporotic bone can be predicted.A 5 year prospective cohort of 560 consecutive patients, undergoing hemiarthroplasty (cemented or uncemented), was evaluated. A nested case-control study to determine risk factors affecting intra-operative fracture was carried out. The Vancouver Classification was used to classify periprosthetic fracture. The MDI score was calculated using radiographs from the uncemented group. As a control (gold standard), Yeung et al's Canal Bone Ratio (CBR) score was also calculated. From this, a receiver operating characteristic (ROC) curve was formulated for both scores and area under the curve (AUC) compared. Intra and inter-observer correlations were determined. Cost analysis was also worked out for adverse outcomes. Four hundred and seven uncemented and one hundred and fifty-three cemented stems were implanted. The use of uncemented implants was the main risk factor for intra-operative periprosthetic fracture. Sixty-two periprosthetic fractures occurred in the uncemented group (15.2%), nine occurred in the cemented group (5.9%), P < 0.001. The revision rate for sustaining a periprosthetic fracture (uncemented group) was 17.7%, P < 0.001 and 90 day mortality 19.7%, P < 0.03. MDI's AUC was 0.985 compared to CBR's 0.948, P < 0.001. The MDI score cut-off to predict fracture was 21, sensitivity 98.3%, specificity 99.8%, positive predictive value 90.5% and negative predictive value 98%. Multivariate regression analysis ruled out any other confounding factors as being significant. The intra and inter-observer Pearson correlation scores were r = 0.99, P < 0.001. JRI uncemented hemiarthroplasty has a significantly higher intra-operative fracture rate. We recommend cemented arthroplasty for hip fractures. We propose a radiographic system that may allow surgeons to select patients who are good

  10. 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 ...

  11. 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.

  12. Defective Autophagy Initiates Malignant Transformation.

    PubMed

    Galluzzi, Lorenzo; Bravo-San Pedro, José Manuel; Kroemer, Guido

    2016-05-19

    In this issue of Molecular Cell, Park et al. (2016) elegantly demonstrate that a partial defect in autophagy supports malignant transformation as it favors the production of genotoxic reactive oxygen species by mitochondria.

  13. 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 ...

  14. Polymer-based solar cells having an active area of 1.6 cm2 fabricated via spray coating

    NASA Astrophysics Data System (ADS)

    Scarratt, N. W.; Griffin, J.; Wang, T.; Zhang, Y.; Yi, H.; Iraqi, A.; Lidzey, D. G.

    2015-12-01

    We demonstrate the fabrication of polymer solar cells in which both a PEDOT:PSS hole transport and a PCDTBT:PC71BM photoactive layer are deposited by spray-casting. Two device geometries are explored, with devices having a pixel area of 165 mm2 attaining a power conversion efficiency of 3.7%. Surface metrology indicates that the PEDOT:PSS and PCDTBT:PC71BM layers have a roughness of 2.57 nm and 1.18 nm over an area of 100 μm2. Light beam induced current mapping reveals fluctuations in current generation efficiency over length-scales of ˜2 mm, with the average photocurrent being 75% of its maximum value.

  15. 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.

  16. 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.

  17. 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.

  18. Topological defects from the multiverse

    SciTech Connect

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

    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.

  19. EUV mask defect mitigation through pattern placement

    NASA Astrophysics Data System (ADS)

    Burns, John; Abbas, Mansoor

    2010-09-01

    One of the challenges of EUVL is to bring EUV mask blank defect levels to zero. With uncertainty on when defect free masks may be routinely available, we explore a possibility for effectively using defective EUV mask blanks in production with a defect avoidance strategy. The key idea is to position the pattern/layout on the blank where the defects do not impact the final wafer image. Assuming that layout designs contain some non-critical areas in which defects can be safely positioned, it may be possible to align these regions with a given, small set of defect positions mapped from an imperfect mask blank. Using a few representative assortment of current-node, full-chip layout patterns we run multiple trials against real blank defect maps with various defect counts successfully. Our goal is to assess the probabilities that defect avoidance will work as a function of mask blank defect count, and by lithography layer.

  20. Repairing native defects on EUV mask blanks

    NASA Astrophysics Data System (ADS)

    Lawliss, Mark; Gallagher, Emily; Hibbs, Michael; Seki, Kazunori; Isogawa, Takeshi; Robinson, Tod; LeClaire, Jeff

    2014-10-01

    Mask defectivity is a serious problem for all lithographic masks, but especially for EUV masks. Defects in the EUV blank are particularly challenging because their elimination is beyond control of the mask fab. If defects have been identified on a mask blank, patterns can be shifted to place as many blank defects as possible in regions where printing impact will be eliminated or become unimportant. For those defects that cannot be mitigated through pattern shift, repair strategies must be developed. Repairing defects that occur naturally in the EUV blank is challenging because the printability of these defects varies widely. This paper describes some types of native defects commonly found and begins to outline a triage strategy for defects that are identified on the blank. Sample defects best suited to nanomachining repair are treated in detail: repairs are attempted, characterized using mask metrology and then tested for printability. Based on the initial results, the viability of repairing EUV blank native defects is discussed.

  1. 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.

  2. Investigation of deep level defects in epitaxial semiconducting zinc sulpho-selenide. Progress report, June 15, 1980-June 14, 1981

    SciTech Connect

    Wessels, B.W.

    1981-02-15

    High conductivity ZnSe single crystalline films have been heteroepitaxially deposited on GaAs substrates using open tube chemical vapor transport. Unintentionally doped films had net donor densities of 10/sup 14/ - 10/sup 16/ cm/sup -3/ and resistivities of 1 to 10/sup 3/ ohm cm. Resistivity was found to be strongly dependent upon zinc partial pressure during deposition. Electron mobilities of the order of 50 to 200 cm/sup 2//V sec were observed which suggested that the films are highly compensated. Properties of the deep level defects in heteroepitaxially grown ZnSe have been investigated using transient capacitance spectroscopy. A series of electron traps were observed with activation energies of 0.33, 0.35, 0.42, 0.71 and 0.86 eV in Au/ZnSe Schottky diodes. Trap concentration ranged from 10/sup 12/ to 10/sup 14/ cm/sup -3/ and depended on the zinc partial pressure. A model for the defect structure of ZnSe was proposed. Growth studies of ZnS/sub x/Se/sub 1-x/ on GaAs were begun.

  3. Effect of ultrasonic cavitation on the diffusivity of a point defect in the passive film on formed Nb in 0.5 M HCl solution.

    PubMed

    Li, D G

    2015-11-01

    This work primarily focused on the influence of ultrasonic cavitation on the transport property of the point defect in the passive film on formed Nb in 0.5M HCl solution via electrochemical techniques based on the point defect model (PDM). The influence of ultrasonic cavitation on the composition and structure of the passive film was detected by X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES). The transport property of a point defect in the passive film was characterized by the diffusivity of the point defect (D0). The influences of the ultrasonic cavitation power, passivated time and the distance between horn bottom and sample surface on D0 were analyzed. The results demonstrated that the passive film formed on Nb was an n-type semiconductor with a donor density (ND) ranging from 10(19) cm(-3) to 10(20) cm(-3) in the case of static state, while the order of ND increased one to two times by applying ultrasonic cavitation during film formation. The diffusivity of the point defect (D0) in the passive film formed on Nb at 0.5 V for 1 h in a 0.5 M HCl solution in the static state was calculated to be 9.704×10(-18) cm(2) s(-1), and it increased to 1.255×10(-16) cm(2) s(-1), 7.259×10(-16) cm(2) s(-1) and 7.296×10(-15) cm(2) s(-1) when applying the 180 W, 270 W and 450 W ultrasonic cavitation powers during film formation. D0 increased with the increment of the ultrasonic cavitation power, and decreased with the increased in formation time and distance between the horn bottom and sample surface. AES results showed the film structure and composition were changed by applying the ultrasonic cavitation. XPS results revealed that the passive film was mainly composed of Nb2O5 in the static state, and the low valence Nb-oxide (NbO) appeared in the passive film except Nb2O5 in the case of applying a 270 W ultrasonic cavitation power.

  4. 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.

  5. EPIDEMIOLOGICAL STUDY OF CHILDREN DIAPHYSEAL FEMORAL FRACTURES

    PubMed Central

    Hoffmann, Cassiano Ricardo; Traldi, Eduardo Franceschini; Posser, Alexandre

    2015-01-01

    Objective: To evaluate the personal, fracture, treatment and complication characteristics among patients with pediatric femoral shaft fractures attended at the pediatric orthopedic service of the Joana de Gusmão Children's Hospital. Methods: This was a retrospective cross-sectional study on a population consisting of patients with femoral shaft fractures, aged between birth and 14 years and 11 months, who were divided into four age groups. Information was obtained from medical records and was transferred to a survey questionnaire to present personal, fracture, treatment and complication variables. Results: The study population consisted of 96 patients. Their mean age was 6.8 years. The cases were predominantly among males, comprising closed fractures on the right side, in the middle third with a single line. Regarding fracture etiology, traffic accidents predominated overall in the sample. Most of the patients (74 to 77.1%) presented femoral fractures as their only injury. Conservative treatment predominated in the group younger than six years of age, and surgical treatment in the group aged 6 to 14 years and 11 months. The complications observed until bone union were: discrepancy, infection and movement limitation. The mean time taken for consolidation was 9.6 ± 2.4 weeks, varying with age. Conclusion: The features of these fractures were similar to those described in the literature and the treatment used showed good results. The Joana de Gusmão Children's Hospital has used the treatment proposed in the literature for pediatric femoral shaft fractures. PMID:27042619

  6. Treatment of Diaphyseal Forearm Fractures in Children

    PubMed Central

    Vopat, Matthew L.; Kane, Patrick M.; Christino, Melissa A.; Truntzer, Jeremy; McClure, Philip; Katarincic, Julia; Vopat, Bryan G.

    2014-01-01

    Both bone forearm fractures are common orthopedic injuries. Optimal treatment is dictated not only by fracture characteristics but also patient age. In the pediatric population, acceptable alignment can tolerate greater fracture displacement due to the bone’s ability to remodel with remaining growth. Generally, these fractures can be successfully managed with closed reduction and casting, however operative fixation may also be required. The optimal method of fixation has not been clearly established. Currently, the most common operative interventions are open reduction with plate fixation versus closed or open reduction with intramedullary fixation. Plating has advantages of being more familiar to many surgeons, being theoretically superior in the ability to restore radial bow, and providing the possibility of hardware retention. Recently, intramedullary nailing has been gaining popularity due to decreased soft tissue dissection; however, a second operation is needed for hardware removal generally 6 months after the index procedure. Current literature has not established the superiority of one surgical method over the other. The goal of this manuscript is to review the current literature on the treatment of pediatric forearm fractures and provide clinical recommendations for optimal treatment, focusing specifically on children ages 3-10 years old. PMID:25002936

  7. 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.

  8. 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.

  9. 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.

  10. 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 ...

  11. Nuclear Pasta: Topology and Defects

    NASA Astrophysics Data System (ADS)

    da Silva Schneider, Andre; Horowitz, Charles; Berry, Don; Caplan, Matt; Briggs, Christian

    2015-04-01

    A layer of complex non-uniform phases of matter known as nuclear pasta is expected to exist at the base of the crust of neutron stars. Using large scale molecular dynamics we study the topology of some pasta shapes, the formation of defects and how these may affect properties of neutron star crusts.

  12. 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 ...

  13. 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.

  14. 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…

  15. Delamination initiated by a defect

    NASA Astrophysics Data System (ADS)

    Biel, A.; Toftegaard, H.

    2016-07-01

    Composite materials in wind turbines are mainly joined with adhesives. Adhesive joining is preferable since it distributes the stresses over a larger area. This study shows how a defect can influence the fracture behaviour of adhesively joined composite. Repeated experiments are performed using double cantilever beam specimens loaded with bending moments. The specimens consist of two 8 mm thick GFRP-laminates which are joined by a 3 mm thick epoxy adhesive. A thin foil close to one of the laminates is used to start the crack. For some of the specimens a defect is created by an initial load-unload operation. During this operation, a clamp is used in order to prevent crack propagation in the main direction. For the specimens without defect, the crack propagates in the middle of the adhesive layer. For the specimens with defect, the crack directly deviates into the laminate. After about 25 mm propagation in the laminate, the crack returns to the adhesive. Compared to the adhesive the fracture energy for the laminate is significantly higher.

  16. 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

  17. 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.

  18. 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

  19. Cellular Defect May Be Linked to Parkinson's

    MedlinePlus

    ... 160862.html Cellular Defect May Be Linked to Parkinson's: Study Abnormality might apply to all forms of ... that may be common to all forms of Parkinson's disease. The defect plays a major role in ...

  20. 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.

  1. 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...

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Various Stone-Wales defects in phagraphene

    NASA Astrophysics Data System (ADS)

    Openov, L. A.; Podlivaev, A. I.

    2016-08-01

    Various Stone-Wales defects in phagraphene, which is a graphene allotrope, predicted recently are studied in terms of the nonorthogonal tight-binding model. The energies of the defect formation and the heights of energy barriers preventing the formation and annealing of the defects are found. Corresponding frequency factors in the Arrhenius formula are calculated. The evolution of the defect structure is studied in the real-time mode using the molecular dynamics method.

  8. 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.

  9. Photocurrent response from photonic crystal defect modes.

    PubMed

    Schartner, Stephan; Nobile, Michele; Schrenk, Werner; Andrews, Aaron M; Klang, Pavel; Strasser, Gottfried

    2008-03-31

    The authors use a quantum well intersubband photodetector fabricated into a two dimensional photonic crystal to investigate the optical defect modes of a single missing hole defect. The modes appear as a local enhancement in spectral photocurrent due to an increased in-coupling of surface incident light when a defect mode is present. The frequencies of these localized modes are tracked as they are varied by the defect geometry and compared to simulations. PMID:18542578

  10. 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.

  11. Electroneutral intrinsic point defects in cadmium chalcogenides

    SciTech Connect

    Kharif, Ya.L.; Kudryashov, N.I.; Strunilina, T.A.

    1987-12-01

    Low-mobility electrically neutral intrinsic point defects were observed in cadmium chalcogenides. It was shown that the concentration of these defects is proportional to the cadmium vapor pressure to the 1/3 power at a constant temperature, and a mechanism for the formation of these defects were proposed.

  12. A fourfold coordinated point defect in silicon.

    PubMed

    Goedecker, Stefan; Deutsch, Thierry; Billard, Luc

    2002-06-10

    Vacancies, interstitials, and Frenkel pairs are considered to be the basic point defects in silicon. We challenge this point of view by presenting density functional calculations that show that there is a stable point defect in silicon that has fourfold coordination and is lower in energy than the traditional defects.

  13. 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.

  14. 7 CFR 52.780 - Defects.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Defects. 52.780 Section 52.780 Agriculture Regulations... Defects. (a) General. The factor of defects refers to the degree of freedom from harmless extraneous material, mutilated cherries, and cherries blemished by scab, hail injury, discoloration, scar tissue,...

  15. 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... 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...

  16. 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.

  17. 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.

  18. Defect disorder in UO{sub 2}

    SciTech Connect

    Hassan, A.-R.; El-Azab, Anter; Yablinsky, Clarissa; Allen, T.

    2013-08-15

    A defect disorder model has been developed to determine equilibrium off-stoichiometry and its spatial variations in UO{sub 2} crystals. The model gives the concentrations of atomic defects and electronic carriers as functions of oxygen partial pressure and temperature in the bulk and near crystal surfaces subject to an oxygen environment. Energetic parameters from published density functional theory calculations have been integrated into the defect disorder model for an accurate determination of the defect density and off-stoichiometry. The ionosorption theory has been used to couple the oxygen environment with the defect state in the crystal as we solved for the defect disorder near crystal surfaces. Contrary to the common belief that hyper-stoichiometry of UO{sub 2} is dominated by oxygen interstitials, the current model predicts that this regime is rather dominated by uranium vacancies. The model predictions also show that, in the presence of surfaces, the point defect concentrations vary by orders of magnitude in the subsurface region relative to the bulk region. Highlights: • Defect disorder in bulk UO2+x is modeled in terms of temperature and oxygen pressure. • The densities of atomic defects and electronic charge carriers are determined. • The model is extended to study the heterogeneity of defect density near crystal surfaces. • The surface effect is modeled using ionosorption theory. • The dominant defect type and off-stoichiometry profile near surface are found.

  19. Novel EUV Mask Blank Defect Repair Developments

    SciTech Connect

    Hau-Riege, S; Barty, A; Mirkarimi, P

    2003-03-31

    The development of defect-free reticle blanks is an important challenge facing the commercialization of extreme ultraviolet lithography (EUVL). The basis of EUVL reticles are mask blanks consisting of a substrate and a reflective Mo/Si multilayer. Defects on the substrate or defects introduced during multilayer deposition can result in critical phase and amplitude defects. Amplitude- or phase-defect repair techniques are being developed with the goal to repair many of these defects. In this report, we discuss progress in two areas of defect repair: (1) We discuss the effect of the residual reflectance variation over the repair zone after amplitude-defect repair on the process window. This allows the determination of the maximum tolerable residual damage induced by amplitude defect repair. (2) We further performed a quantitative assessment of the yield improvement due to defect repair. We found that amplitude- and phase-defect repair have the potential to significantly improve mask blank yield. Our calculations further show that yield can be maximized by increasing the number of Mo/Si bilayers.

  20. 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.

  1. 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

  2. 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 ...

  3. 7 CFR 42.106 - Classifying and recording defects.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... container is scored only once for these two defects since the rust condition can be atributed to the leak... “leaker” (a critical defect) and not as “pitted rust” (a major defect). (2) Unrelated defects are...

  4. 7 CFR 42.106 - Classifying and recording defects.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... container is scored only once for these two defects since the rust condition can be atributed to the leak... “leaker” (a critical defect) and not as “pitted rust” (a major defect). (2) Unrelated defects are...

  5. 7 CFR 42.106 - Classifying and recording defects.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... container is scored only once for these two defects since the rust condition can be atributed to the leak... “leaker” (a critical defect) and not as “pitted rust” (a major defect). (2) Unrelated defects are...

  6. 7 CFR 42.106 - Classifying and recording defects.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... container is scored only once for these two defects since the rust condition can be attributed to the leak... “leaker” (a critical defect) and not as “pitted rust” (a major defect). (2) Unrelated defects are...

  7. 7 CFR 42.106 - Classifying and recording defects.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... container is scored only once for these two defects since the rust condition can be atributed to the leak... “leaker” (a critical defect) and not as “pitted rust” (a major defect). (2) Unrelated defects are...

  8. 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 ...

  9. 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.

  10. Electronic Defect States in Polyaniline.

    NASA Astrophysics Data System (ADS)

    Ginder, John Matthew

    The electronic defect states of the conducting polymer polyaniline are studied by a variety of magnetic and optical techniques. The insulating emeraldine base form (EB) of polyaniline can be converted to the conducting emeraldine salt form (ES) by treatment with aqueous acids such as HCl. This "protonic acid doping" process occurs via the bonding of protons to the polymer chain, without altering the number of chain electrons. Magnetic susceptibility studies reveal that a roughly linear growth of the Pauli paramagnetic susceptibility, and an increase in the density of Curie-like spins, accompanies this conversion. Consequently, the protonation-induced defects are mainly spin-1/2 polarons; further, the linear growth of the Pauli susceptibility suggests that fully protonated regions--metallic islands --grow with increasing doping level. The electronic structure of the metallic phase is proposed to be that of a polaron lattice with electronic bandwidth ~0.4 eV and polaron decay length ~2 A. The defects which accomodate excess charge in EB were also studied by near-steady-state photoinduced absorption experiments. Upon photoexcitation into the 2 eV absorption band in EB, several photoinduced features evolved. Induced bleachings of the existing transitions at 2.0 and 3.7 eV were observed; induced absorptions were found at 0.9, 1.4, and 3.0 eV. The 2.0 eV bleaching is consistent with the production of molecular charge-transfer excitons, which may relax to a different ring conformation causing long-lived bleaching, or to two separate charges on a single chain. Indeed, the induced absorptions at 1.4 and 3.0 eV are, by analogy with similar protonation -induced absorptions and by their bimolecular recombination kinetics, assigned to photoexcited polarons. Light-induced electron spin resonance experiments confirm the presence of photogenerated spins upon pumping into the excitonic absorption. Near-steady-state photoconductivity measurements on EB reveal a very small induced

  11. Optical modeling of extraoral defects.

    PubMed

    Reitemeier, Bernd; Notni, Gunther; Heinze, Matthias; Schöne, Christine; Schmidt, Annette; Fichtner, Dieter

    2004-01-01

    In order to reduce the stress caused to patients by conventional methods of modeling using computed tomography (CT) or magnetic resonance imaging (MRI), an optical modeling process has been developed for extraoral defects and body areas. The selected body part is digitized using optical 3-coordinate measuring technology, providing an extensive data record. This is adapted for further use by equalizing the point clouds to obtain a Computer Aided Design (CAD) model, which is converted to a physical model by means of a stereolithographic process. With this technology, the patient's physical and psychological stress may be reduced. This article describes a technique for optical modeling of an ocular prosthesis.

  12. Defect Detection in Correlated Noise

    NASA Astrophysics Data System (ADS)

    Dogandžić, Aleksandar; Eua-Anant, Nawanat

    2004-02-01

    We present methods for detecting NDE defect signals in correlated noise having unknown covariance. The proposed detectors are derived using the statistical theory of generalized likelihood ratio (GLR) tests and multivariate analysis of variance (MANOVA). We consider both real and complex data models. To allow accurate estimation of the noise covariance, we incorporate secondary data containing only noise into detector design. Probability distributions of the GLR test statistics are derived under the null hypothesis, i.e. assuming that the signal is absent, and used for detector design. We apply the proposed methods to simulated and experimental data and demonstrate their superior performance compared with the detectors that neglect noise correlation.

  13. 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.

  14. Theory of defects in Abelian topological states

    NASA Astrophysics Data System (ADS)

    Barkeshli, Maissam; Jian, Chao-Ming; Qi, Xiao-Liang

    2013-12-01

    The structure of extrinsic defects in topologically ordered states of matter is host to a rich set of universal physics. Extrinsic defects in 2+1-dimensional topological states include linelike defects, such as boundaries between topologically distinct states, and pointlike defects, such as junctions between different line defects. Gapped boundaries in particular can themselves be topologically distinct, and the junctions between them can localize topologically protected zero modes, giving rise to topological ground-state degeneracies and projective non-Abelian statistics. In this paper, we develop a general theory of point defects and gapped line defects in 2+1-dimensional Abelian topological states. We derive a classification of topologically distinct gapped boundaries in terms of certain maximal subgroups of quasiparticles with mutually bosonic statistics, called Lagrangian subgroups. The junctions between different gapped boundaries provide a general classification of point defects in topological states, including as a special case the twist defects considered in previous works. We derive a general formula for the quantum dimension of these point defects and a general understanding of their localized “parafermion” zero modes and we define a notion of projective non-Abelian statistics for them. The critical phenomena between topologically distinct gapped boundaries can be understood in terms of a general class of quantum spin chains or, equivalently, “generalized parafermion” chains. This provides a way of realizing exotic 1+1D generalized parafermion conformal field theories in condensed-matter systems.

  15. 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.

  16. Elastic fields and moduli in defected graphene.

    PubMed

    Dettori, Riccardo; Cadelano, Emiliano; Colombo, Luciano

    2012-03-14

    By means of tight-binding atomistic simulations we study a family of native defects in graphene which have recently been detected experimentally. Their formation energy is found to be as large as several electronvolts, consistent with the empirical evidence of high crystalline quality in most graphene samples. Defects, especially if associated with bond reconstructions, induce sizable deformation and stress fields with a spatial distribution closely related to their actual symmetry. The description of such fields proposed here is believed to be useful for the unambiguous characterization of images obtained by electron microscopy. We also argue that they define the basin of mutual interaction between two nearby defects. Finally, we provide evidence that defects differently affect the linear elastic moduli of monolayer graphene. In general, both the Young modulus and the Poisson ratio are decreased, but their dependence upon the defect surface density is remarkably more pronounced for vacancy-like than for number-like defects.

  17. Surface defects and temperature on atomic friction.

    PubMed

    Fajardo, O Y; Mazo, J J

    2011-09-01

    We present a theoretical study of the effect of surface defects on atomic friction in the stick-slip dynamical regime of a minimalistic model. We focus on how the presence of defects and temperature change the average properties of the system. We have identified two main mechanisms which modify the mean friction force of the system when defects are considered. As expected, defects change the potential profile locally and thus affect the friction force. But the presence of defects also changes the probability distribution function of the tip slip length and thus the mean friction force. We corroborated both effects for different values of temperature, external load, dragging velocity and damping. We also show a comparison of the effects of surface defects and surface disorder on the dynamics of the system. PMID:21846940

  18. 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

  19. 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

  20. 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

  1. Primordial inhomogeneities from massive defects during inflation

    NASA Astrophysics Data System (ADS)

    Firouzjahi, Hassan; Karami, Asieh; Rostami, Tahereh

    2016-10-01

    We consider the imprints of local massive defects, such as a black hole or a massive monopole, during inflation. The massive defect breaks the background homogeneity. We consider the limit that the physical Schwarzschild radius of the defect is much smaller than the inflationary Hubble radius so a perturbative analysis is allowed. The inhomogeneities induced in scalar and gravitational wave power spectrum are calculated. We obtain the amplitudes of dipole, quadrupole and octupole anisotropies in curvature perturbation power spectrum and identify the relative configuration of the defect to CMB sphere in which large observable dipole asymmetry can be generated. We observe a curious reflection symmetry in which the configuration where the defect is inside the CMB comoving sphere has the same inhomogeneous variance as its mirror configuration where the defect is outside the CMB sphere.

  2. Enhanced thermoelectric performance of defected silicene nanoribbons

    NASA Astrophysics Data System (ADS)

    Zhao, W.; Guo, Z. X.; Zhang, Y.; Ding, J. W.; Zheng, X. J.

    2016-02-01

    Based on non-equilibrium Green's function method, we investigate the thermoelectric performance for both zigzag (ZSiNRs) and armchair (ASiNRs) silicene nanoribbons with central or edge defects. For perfect silicene nanoribbons (SiNRs), it is shown that with its width increasing, the maximum of ZT values (ZTM) decreases monotonously while the phononic thermal conductance increases linearly. For various types of edges and defects, with increasing defect numbers in longitudinal direction, ZTM increases monotonously while the phononic thermal conductance decreases. Comparing with ZSiNRs, defected ASiNRs possess higher thermoelectric performance due to higher Seebeck coefficient and lower thermal conductance. In particular, about 2.5 times enhancement to ZT values is obtained in ASiNRs with edge defects. Our theoretical simulations indicate that by controlling the type and number of defects, ZT values of SiNRs could be enhanced greatly which suggests their very appealing thermoelectric applications.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Defects in Ge+-preamorphized silicon

    NASA Astrophysics Data System (ADS)

    Chen, Peng-Shiu; Hsieh, T. E.; Hwang, Yih-Chyang; Chu, Chih-Hsun

    1999-11-01

    This work studied the morphology and annealing behaviors of extended defects in Si subjected to various Ge+ preamorphization and BF2+ implantation conditions. The extended defects formed were near the specimen surface when Ge+ implantation energy and dose amount were low. During subsequent annealing, the end-of-range (EOR) loops were enlarged and then moved out of the specimen. High energy/low dose Ge+ implantation generated a damaged layer which initially transformed into a wide zone containing dislocation loops and rodlike defects in the annealed specimen. As the annealing proceeded, the width of defective zone gradually shrunk so that most of the extended defects could be annihilated by defect rejection/recombination process. In addition to the category II defects found in previous investigations, hairpin dislocations emerged in high energy/high dose Ge+-implanted specimens. In this specimen, rodlike defects and hairpin dislocations could be removed by annealing, while the EOR loops became relatively inert so that their removal would require high temperatures and/or long annealing times. Microwave plasma surface treatment was also carried out to form a nitride layer on specimen surface. Experimental results indicate that in addition to effectively reducing the size of EOR loops, surface nitridation might serve as a vacancy source injecting vacancies into Si to annihilate the interstitials bounded by dislocation loops. Reduction in the defect size was pronounced when bias voltage was added to the plasma process. However, radiation damage might occur with too high of a bias voltage.

  9. 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.

  10. 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

  11. 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.

  12. Automatic thermographic image defect detection of composites

    NASA Astrophysics Data System (ADS)

    Luo, Bin; Liebenberg, Bjorn; Raymont, Jeff; Santospirito, SP

    2011-05-01

    Detecting defects, and especially reliably measuring defect sizes, are critical objectives in automatic NDT defect detection applications. In this work, the Sentence software is proposed for the analysis of pulsed thermography and near IR images of composite materials. Furthermore, the Sentence software delivers an end-to-end, user friendly platform for engineers to perform complete manual inspections, as well as tools that allow senior engineers to develop inspection templates and profiles, reducing the requisite thermographic skill level of the operating engineer. Finally, the Sentence software can also offer complete independence of operator decisions by the fully automated "Beep on Defect" detection functionality. The end-to-end automatic inspection system includes sub-systems for defining a panel profile, generating an inspection plan, controlling a robot-arm and capturing thermographic images to detect defects. A statistical model has been built to analyze the entire image, evaluate grey-scale ranges, import sentencing criteria and automatically detect impact damage defects. A full width half maximum algorithm has been used to quantify the flaw sizes. The identified defects are imported into the sentencing engine which then sentences (automatically compares analysis results against acceptance criteria) the inspection by comparing the most significant defect or group of defects against the inspection standards.

  13. 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.

  14. 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

  15. 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.

  16. Characterization of rat calvarial nonunion defects.

    PubMed

    Schmitz, J P; Schwartz, Z; Hollinger, J O; Boyan, B D

    1990-01-01

    This study examined the healing of nonunions by describing the histology and ultrastructural appearance of craniotomy defects as a model. Bone defects (3, 4 and 8 mm) were created in the calvaria of adult rats. Central and peripheral specimens of 8-mm defects were retrieved at 1, 3, 7, 10, 14, 21, 28 and 42 days and examined using both light and transmission electron microscopy. Specimens from the 3- and 4-mm defects were retrieved at 28 days and examined using light microscopy. In all sizes of defects, bony repair was consistently localized to the dural side of the defect. The 3- and 4 mm defects demonstrated the greatest degree of osseous bridging and evidence of normal osseous repair throughout the defect. The 8-mm defects repaired in general with the formation of nonunions which contained a small amount of bone at the periphery and fibrous connective tissue. Bone formation was evident at 10 days in the peripheral regions of the 8-mm defects and exhibited bony peninsulas with normal primary calcification fronts. Matrix vesicles containing hydroxyapatite-like crystals were present. In contrast, the central regions of the 8-mm defects were characterized by several islands of cartilage-like cells which stained metachromatically with toluidine blue. Transmission electron microscopy of this region at 14 days demonstrated a dense, collagenous extracellular matrix with matrix vesicles infiltrating the collagen bundles. There was no evidence of crystal formation in the matrix vesicles nor of calcification in the collagenous matrix. At 21 days, both the central and peripheral regions of the 8-mm calvarial nonunions were characterized by dense fibrous connective tissue repair and inactive fibroblasts.(ABSTRACT TRUNCATED AT 250 WORDS)

  17. Stone-Wales defects in silicene: Formation, stability, and reactivity of defect sites

    NASA Astrophysics Data System (ADS)

    Sahin, H.; Sivek, J.; Li, S.; Partoens, B.; Peeters, F. M.

    2013-07-01

    During the synthesis of ultrathin materials with hexagonal lattice structure Stone-Wales (SW) type of defects are quite likely to be formed and the existence of such topological defects in the graphenelike structures results in dramatic changes of their electronic and mechanical properties. Here we investigate the formation and reactivity of such SW defects in silicene. We report the energy barrier for the formation of SW defects in freestanding (˜2.4 eV) and Ag(111)-supported (˜2.8 eV) silicene and found it to be significantly lower than in graphene (˜9.2 eV). Moreover, the buckled nature of silicene provides a large energy barrier for the healing of the SW defect and therefore defective silicene is stable even at high temperatures. Silicene with SW defects is semiconducting with a direct band gap of 0.02 eV and this value depends on the concentration of defects. Furthermore, nitrogen substitution in SW-defected silicene shows that the defect lattice sites are the least preferable substitution locations for the N atoms. Our findings show the easy formation of SW defects in silicene and also provide a guideline for band gap engineering in silicene-based materials through such defects.

  18. 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...

  19. 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...

  20. 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...

  1. 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.

  2. Microphthalmia with linear skin defects syndrome.

    PubMed

    García-Rabasco, Ana; De-Unamuno, Blanca; Martínez, Francisco; Febrer-Bosch, Isabel; Alegre-de-Miquel, Víctor

    2013-01-01

    Microphthalmia with linear skin defects (MLS) or microcornea, dermal aplasia and sclerocornea (MIDAS) syndrome is a rare X-linked-dominant disorder. We present a patient with agenesis of corpus callosum, ocular abnormalities, and multiple skin defects. The cytogenetic studies of the MLS critical region (Xp22.2) were normal, but a skewed X-chromosome inactivation pattern (85:15) was observed.

  3. 49 CFR 215.123 - Defective couplers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Defective couplers. 215.123 Section 215.123 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD FREIGHT CAR SAFETY STANDARDS Freight Car Components Draft System § 215.123 Defective couplers. A railroad may...

  4. Defect-Tolerant Monolayer Transition Metal Dichalcogenides

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

    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 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 very similar orbital composition. This indicates a bonding/anti-bonding 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 non-polar nanoribbons of the TMDs where we find that only the defect sensitive materials form edge states within the band gap.

  5. Simple intrinsic defects in InAs :

    SciTech Connect

    Schultz, Peter Andrew

    2013-03-01

    This Report presents numerical tables summarizing properties of intrinsic defects in indium arsenide, InAs, as computed by density functional theory using semi-local density functionals, intended for use as reference tables for a defect physics package in device models.

  6. Defect chemistry of silver selenogallate

    NASA Astrophysics Data System (ADS)

    Whittaker, Matthew Thomas

    2007-12-01

    The source of 9.3 mum absorption in silver selenogallate, AgGaSe 2 was investigated. Infrared spectrophotometric analysis of two as-received, reportedly stoichiometric, single crystals found 9.3 mum absorption coefficients of 0.109 and 0.101 cm-1. Infrared transmission of the slabs was otherwise uniform at 0.007 cm-1 through the range 6--12 gym. X-ray fluorescence measurements did not indicate an extrinsic impurity was responsible for the absorption. Intrinsic defect reactions were investigated and a Brouwer diagram was constructed to determine probable native defects. Analysis of the Brouwer diagram led to the hypothesis that the 9.3 mum absorption was caused by a native selenium vacancy. A series of heat treatments were conducted at 790°C with selenium partial pressures of 0.026, 0.040, 0.057, 0.138, and 0.243 atmospheres. Heat treatments below 0.060 atmospheres selenium partial pressure resulted in null or increased absorption at 9.3 mum up to 0.128 cm-1. Heat treatment at 0.243 atmospheres selenium partial pressure resulted in a decrease of the 9.3 mum absorption coefficient of 63% to 0.037 cm-1. A linear least-squares regression of the 9.3 mum absorption coefficient versus selenium partial pressure during heat treatment resulted in an equation for the absorption coefficient. alpha9.3mum = -0.4048 (PSe) atm -1cm-1 + 0.1322cm -1. The highest electrical resistivity of AgGaSe2 was measured at 7.6 x 1011 Ocm for a crystal with a 9.3 mum absorption coefficient of 0.037 cm-1. A linear least-squares regression of the 9.3 mum absorption coefficient versus bulk electrical resistivity resulted in an equation for the resistivity: rho = -7 x 1012 alpha9.3mumO cm2 + 1 x 1012 O cm. Thus, the electrical resistivity increases as the stoichiometric composition is approached and may be used as a measure of stoichiometry. The deleterious 9.3 mum absorption has not been entirely eliminated; however, the reduction in the 9.3 mum absorption coefficient from greater than 0.100 cm-1

  7. Characterizing solute-lean defects in superalloys

    NASA Astrophysics Data System (ADS)

    Samuelsson, E.; Domingue, J. A.; Maurer, G. E.

    1990-08-01

    Solute-lean defects, commonly called white spots, are frequently found in superalloys. These defects limit the service life of components made from superalloys, and alloy producers have devoted intense study to their characterization and elimination. Recent work shows that solute lean defects can be classified as "discrete," "diffuse" and "mini," and can be further classified into "clean" and "dirty" white spots. More than one formation mechanism for white spots is exemplified by the chemical and morphological differences between discrete, diffuse and mini white spots. White spot detection depends on the thermomechanically developed precipitation of hardening phases, coupled with specific etches that preferentially react to microstructure differences. The white spot defect is indigenous to the vacuum arc remelting process, but defect formation can be minimized by careful process control.

  8. 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.

  9. 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.

  10. Defect and functionalized graphene for supercapacitor electrodes

    NASA Astrophysics Data System (ADS)

    Taluja, Yogita; SanthiBhushan, Boddepalli; Yadav, Shekhar; Srivastava, Anurag

    2016-10-01

    The structural, electronic and transport properties of defected (single vacancy and double vacancy) and nitrogen functionalized graphene sheets have been analysed within the framework of Density Functional Theory (DFT) and non-equilibrium Green's function (NEGF) formalism for their possible application as supercapacitor electrodes. Formation energy calculations reveal the increasing stability of defect with nitrogen functional doping concentration at its edges. The extracted electronic properties reveal the presence of acceptor-type energy levels at Fermi level in the defected and functionalized sheets. Transport studies portray remarkable increase in electrical conductivity of graphene sheet after the formation of single vacancy defect and its functionalization. Especially, the Single Vacancy Trimerized pyridine-type defect (SVT) configuration has demonstrated superior thermodynamic stability as well as electrical conductance in comparison to all the other configurations.

  11. Wavenumber and Defect Distributions in Undulation Chaos

    NASA Astrophysics Data System (ADS)

    Daniels, Karen E.; Bodenschatz, Eberhard

    2000-11-01

    We report experimental results on thermally driven convection in a large aspect ratio inclined layer with a fluid of Prandtl number σ ≈ 1. Very close to the onset of convection for inclination angles between 20 and 70 degrees, we find the defect turbulent state of undulation chaos (Daniels, Plapp, and Bodenschatz. Phys. Rev. Lett. 84:5320). We characterize this state by determining the defect locations and the wavenumber distribution. A snapshot of the pattern, as well as its wavenumber distribution, can be well-reconstructed from a perfect underlying undulation pattern and the phase field given by the point defects. The defect density distribution shows a crossover from a Poisson to a squared Poisson distribution. By measuring the creation, annihilation, inflow, and outflow rates of defects we can quantitatively explain this behavior. This work is supported by the National Science Foundation DMR-0072077.

  12. Stafne bone defect: report of two cases.

    PubMed

    Münevveroğlu, A P; Aydın, K C

    2012-01-01

    Stafne bone defects are asymptomatic lingual bone depressions of the lower jaw. In 1942, Stafne described for the first time 35 asymptomatic, radiolucent cavities, unilaterally located in the posterior region of the mandible, between the mandibular angle and the third molar, below the inferior dental canal and slightly above the basis mandibulae. In this study, the clinical and radiological characteristics of 2 cases of Stafne bone defects were described. Orthopantomograph and CBCT were used for diagnosing the defects. The bone defects of two patients in this study were asymptomatic and any other bone lesions, such as cysts and tumors, were excluded because no signs of inflammatory or tumoral changes were evident Therefore, surgery was not considered and the patients were followed for 1 year. Stafne bone defect was an incidental finding, presenting no evolutionary changes, and as such conservatory therapy based on periodic controls was indicated. Currently, complementary techniques such as CT are sufficient to establish a certain diagnosis.

  13. 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.

  14. Optical signatures of defects in nitride semiconductors

    NASA Astrophysics Data System (ADS)

    Armstrong, Andrew

    2012-02-01

    Despite successful commercialization of GaN-based light emitting diodes (LEDs) and high frequency transistors, crystal defects continue to have a strong and often undesired impact on the opto-electronic properties of the III-Nitride family of materials. Fully realizing the potential of this fascinating materials system requires a better understanding of the physical origin of defects, their dependence on both substrate quality and epitaxial growth conditions, and their influence on electrical and optical properties. This talk will discuss the use of deep level optical spectroscopy (DLOS) to quantitatively study defect states in GaN-based materials. As a photocapacitance technique, DLOS is able to probe defect levels that are otherwise inaccessible to thermally-stimulated defect spectroscopies in wide band gap materials, such as the III-Nitrides. DLOS quantifies both the energy level and density of defects and probes defect states with nanoscale depth resolution. Beyond the canonical application of DLOS to thin films, this talk will describe new developments of DLOS to quantitatively study defect states in a wide variety of structures with nanoscale dimensionality, including InGaN/GaN multi-quantum wells and AlGaN/GaN core-shell nanowires. The microscopic origin of observed defect states and their influence on the electrical and optical properties of GaN-based LEDs and nanowire devices will be discussed. The reported studies establish DLOS as a critical technique for nanoscale dimensional defect metrology that is able to advance the development of conventional and emerging opto-electronic devices.

  15. 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.

  16. Stability of Si-Interstitial Defects: From Point to Extended Defects

    SciTech Connect

    Kim, Jeongnim; Kirchhoff, Florian; Wilkins, John W.; Khan, Furrukh S.

    2000-01-17

    Trends in the growth of extended interstitial defects are extracted from extensive tight-binding and ab inito local density approximation simulations. With an increasing number of interstitials, the stable defect shape evolves from compact to chainlike to rodlike. The rodlike {l_brace}311{r_brace} defect, formed from (011) interstitial chains, is stabilized as it grows, elongating in the chain direction. Accurate parametrization of the defect-formation energy on the number of interstitials and interstitial chains, together with the anisotropy of the interstitial capture radius, enables macroscopic defect-growth simulations. (c) 2000 The American Physical Society.

  17. Interleukin-6 stimulates defective angiogenesis

    PubMed Central

    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

    2015-01-01

    The cytokine interleukin-6 (IL-6) 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 IL-6 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, IL-6-stimulated aortic ring vessel sprouts had defective pericyte coverage compared to VEGF-stimulated vessels. The mechanism of IL-6 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-IL-6 antibody, pericyte coverage of vessels was restored. In addition, in human ovarian cancer biopsies there was an association between levels of IL-6mRNA, Jagged1 and Ang2. Our findings have implications for the use of cancer therapies that target VEGF or IL-6 and for understanding abnormal angiogenesis in cancers, chronic inflammatory disease and stroke. PMID:26081809

  18. Thyroid gland development and defects.

    PubMed

    Kratzsch, Juergen; Pulzer, Ferdinand

    2008-02-01

    During the functional ontogenesis of the thyroid gland an increasing number of transcription factors play fundamental roles in thyroid-cell differentiation, maintenance of the differentiated state, and thyroid-cell proliferation. The early growth and development of the fetal thyroid appears to be generally independent of thyroid-stimulating hormone (TSH). TSH and thyroxine (T4) levels increase from the 12th week of gestation until delivery, whereas triiodothyronine (T3) levels remain relatively low. At birth, a cold-stimulated short-lived TSH surge is observed, followed by a TSH decrease until day 3 or 4 of life by T4 feedback inhibition. Disorders of thyroid gland development and/or function are relatively common, affecting approximately one newborn infant in 2000-4000. The most prevalent disease, congenital hypothyroidism, is frequently caused by genetic defects of transcription factors involved in the development of the thyroid or pituitary gland. A major cause of congenital hyperthyroidism is the transplacental passage of stimulating thyrotropin antibodies from the mother to the fetus. Hypothyroxinaemia or hypotriiodthyroninaemia is frequently observed in preterm infants with or without severe non-thyroidal illness. Whereas congenital hypo- and hyperthyroidism may be treated successfully with T4 or thyrostatic drugs, there is still insufficient evidence on whether the use of T4 for treatment of the latter condition results in changes in neonatal morbidity or reductions in neurodevelopmental impairment.

  19. 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.

  20. Defect-Defect Interaction in Single-Walled Carbon Nanotubes Under Torsional Loading

    NASA Astrophysics Data System (ADS)

    Huq, Abul M. A.; Bhuiyan, Abuhanif K.; Liao, Kin; Goh, Kheng Lim

    This paper presents an analysis of interactions between a pair of Stone-Wales (SW) defects in a single-walled carbon nanotube (SWCNT) that has been subjected to an external torque. Defect pairs, representing the different combinations of SW defect of A (SW-A) and B (SW-B) modes, were incorporated in SWCNT models of different chirality and diameter and solved using molecular mechanics. Defect-defect interaction was investigated by evaluating the C-C steric interactions in the defect that possesses the highest potential energy, E, as a function of inter-defect distance, D. This study reveals that the deformation of the C-C bond is attributed to bond stretching and bending. In the SW-B defects, there is an additional contributor arising from the dihedral angular deformation. The magnitude of E depends on the type of defect but the profile of the E versus D curve depends on the orientation of the defects. The largest indifference length, D0, beyond which two defects cease to interact, is approximately 30 Å. When the angular displacement of the tube increases two-fold, E increases, but the profile of the E versus D curve is not affected. The sense of rotation affects the magnitude of E but not the profile of the E versus D curve.

  1. Defect annealing in neutron and ion damaged silicon: Influence of defect clusters and doping

    NASA Astrophysics Data System (ADS)

    Fleming, R. M.; Seager, C. H.; Bielejec, E.; Vizkelethy, G.; Lang, D. V.; Campbell, J. M.

    2010-03-01

    We have explored defect annealing in radiation damaged silicon in a regime characterized by defect clusters and higher doping. Several types of pnp and npn Si bipolar transistors have been irradiated with ions and neutrons, then isochronally annealed from 300 to 600 K to study the evolution of deep level transient spectroscopy (DLTS) defect signatures. Variations in these data with radiation environment, Fermi level, annealing temperature, and doping density have been used to separate the contributions of three dominant defects to the DLTS defect spectra. We find that the normal Si divacancy and a divacancylike defect with similar properties make similar contributions to a DLTS peak normally associated with transitions from the single minus charge state of the divacancy. However the latter defect is clearly associated with the presence of defect clusters. The vacancy-donor center can also contribute to this high temperature DLTS signature, and its relative importance can be quantitatively assessed by varying doping density and the bias applied to the sample p/n junctions during annealing, and also by the observation that another, donor-related defect grows in as this center anneals. The ratio of vacancy-donor and vacancy-oxygen pairs appears to accurately follow that seen in earlier studies of gamma-irradiated Si. Discussions are presented concerning the effects of defect clustering on the structure, appearance, and evolution of the defects we have identified.

  2. 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

  3. 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%.

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. Defects in liquid crystal nematic shells

    NASA Astrophysics Data System (ADS)

    Fernandez-Nieves, A.; Utada, A. S.; Vitelli, V.; Link, D. R.; Nelson, D. R.; Weitz, D. A.

    2006-03-01

    We generate water/liquid crystal (LC)/water double emulsions via recent micro-capillary fluidic devices [A. S. Utada, et.al. Science 308, 537 (2005)]. The resultant objects are stabilized against coalescence by using surfactants or adequate polymers; these also fix the boundary conditions for the director field n. We use 4-pentyl-4-cyanobiphenyl (5CB) and impose tangential boundary conditions at both water/LC interfaces by having polyvinyl alcohol (PVA) dispersed in the inner and outer water phases. We confirm recent predictions [D. R. Nelson, NanoLetters 2, 1125 (2002)] and find that four strength s=+1/2 defects are present; this is in contrast to the two s=+1 defect bipolar configuration observed for bulk spheres [A. Fernandez-Nieves, et.al. Phys. Rev. Lett. 92, 105503 (2004)]. However, these defects do not lie in the vertices of a tetrahedron but are pushed towards each other until certain equilibration distance is reached. In addition to the four defect shells, we observe shells with two s=+1 defects and even with three defects, a s=+1 and two s=+1/2. We argue these configurations arise from nematic bulk distortions that become important as the shell thickness increases. Finally, by adding a different surfactant, sodium dodecyl sulphate (SDS), to the outer phase, we can change the director boundary conditions at the outermost interface from parallel to homeotropic, to induce coalescing of the two pair of defects in the four defect shell configuration to yield two defect bipolar shells.

  9. Management of extensive frontal cranioplasty defects.

    PubMed

    Hatamleh, Muhanad M; Cartmill, Maria; Watson, Jason

    2013-11-01

    Cranioplasty is a medical technique to correct cranial bone defects. Depending on the size and location of the defect, a bone substitute can be used to replace the missing bone. Frontal bone defects are important to patients in terms of cosmetics because they are visible. Advances in computer design allow the production of customized implants with improved cosmetic and functional results. This report describes hybrid optimization of three-dimensional technological methods along with traditional methods toward the manufacture of deep-buried titanium implants, restoring frontal skull defects for 4 patients. A three-dimensional model was produced from the computed tomographic scan data of 3 patients using an in-house three-dimensional printer. A new approach was followed in treating the fourth patient. The defect was restored using preoperative scan before cranioplasty. These data were transported digitally into the defect skull to recreate the bone contour required, and a three-dimensional model was produced from the "new" digital model using the three-dimensional printer. Defect areas of the patients were large and measured 101.21 × 123.35 (vertical × horizontal) in average (mm). Conventional wax-up of the defect was carried to restore normal conformity. A titanium sheet (0.5 mm) was swaged into the desired shape; however, convexity of the defect area makes titanium swaging challenging, especially at the deep lateral undercuts. Making side flanges at reasonable lengths made it easy to swage without creasing. Three-dimensional models aided to produce accurately fitting plates. Finally, the sequential method of using both digital and manual procedures is a low-cost, reliable, accurate, and reproducible method.

  10. The mechanics of defect detection in vibrothermography

    NASA Astrophysics Data System (ADS)

    Renshaw, Jeremy Blake

    Vibrothermography is a nondestructive evaluation (NDE) technique that is used to detect surface and sub-surface defects such as cracks, disbonds, and delaminations through observations of vibration-induced frictional heat generation at defects. Frictional heating is observed using an infrared (IR) camera and is used to determine the presence and location of defects. There is a large industrial interest in vibrothermography due to its ability to rapidly detect defects over a large area. Another motivation for using this technology is its ability to find defects, such as tightly-closed cracks, that can be missed using other common NDE techniques. A major hindrance to the widespread application of vibrothermography has been an inability to quantify the reliability and capability of the inspection due to insufficient knowledge of the underlying physics of vibrothermography. The purpose of this work is to further understand the physics controlling defect detection in vibrothermography. The influence of vibration was studied through the use of synthetic defects and noncontact measures of vibration. Numerous samples of aluminum, brass, titanium, and carbon fiber-reinforced polymer composites were used to study the physics of heat generation to isolate the different sources of heat generation in metals and composites. The effects of crack closure on heat generation were studied and a method was developed to accurately measure crack closure stresses using vibrothermography. Finally, the effect of friction and heat generation on rubbing crack faces was observed using techniques such as profilometry, optical microscopy, and scanning electron microscopy. This work describes some of the fundamental parameters affecting heat generation and methods to improve defect detection reliability. This research provides a foundation for creating statistical models to improve the defect detection process using vibrothermography.

  11. Point Defects in SiC

    NASA Astrophysics Data System (ADS)

    Zvanut, Mary Ellen

    2004-03-01

    Production of high frequency, high power electronic devices using wide bandgap semiconductors has spurred renewed interest in point defects in SiC. Recent electron paramagnetic resonance (EPR) spectroscopy studies focus on centers in as-grown high purity semi-insulating substrates because intrinsic defects are thought to compensate unavoidable shallow centers, thus creating the high resistivity required. The EPR studies address the chemical/structural composition of the defects, the defect level (energy with respect to a band edge with which the defect can accept or release an electron) and thermal stability. Thus far, the positively charged carbon vacancy, the Si vacancy, a carbon-vacancy/carbon antisite pair, and several as yet-unidentified centers have been observed in as-grown electronic-grade 4H-SiC [1-3]. The talk will review the types of defects recently identified in SiC and discuss their possible relationship to compensation. The photo-induced EPR experiments used to determine defect levels will be discussed, with a particular focus on the carbon vacancy. The use of high frequency EPR to resolve the many different types of centers in SiC will also be covered. Finally, the presentation will review the thermal stability of the intrinsic defects detected in as-grown 4H SiC. 1. M. E. Zvanut and V. V. Konovalov, Appl. Phys. Lett. 80, 410 (2002). 2. N.T. Son, Z. Zolnai, and E. Janzen, Phys. Rev. B64, 2452xx (2003). 3. W.E. Carlos, E.R. Glaser, and B.V. Shanabrook, in Proceedings of the 22nd conference on Defects in Semiconductors, Aarhus, Denmark, July 2003.

  12. Metastable Defects in Tritiated Amorphous Silicon

    SciTech Connect

    Ju, T.; Whitaker, J.; Zukotynski, S.; Kherani, N.; Taylor, P. C.; Stradins, P.

    2007-01-01

    The appearance of optically or electrically induced defects in hydrogenated amorphous silicon (a-Si:H), especially those that contribute to the Staebler-Wronski effect, has been the topic of numerous studies, yet the mechanism of defect creation and annealing is far from clarified. We have been observing the growth of defects caused by tritium decay in tritiated a Si-H instead of inducing defects optically. Tritium decays to {sup 3}He, emitting a beta particle (average energy of 5.7 keV) and an antineutrino. This reaction has a half-life of 12.5 years. In these 7 at.% tritium-doped a-Si:H samples each beta decay will create a defect by converting a bonded tritium to an interstitial helium, leaving behind a silicon dangling bond. We use ESR (electron spin resonance) and PDS( photothermal deflection spectroscopy) to track the defects. First we annealed these samples, and then we used ESR to determine the initial defect density around 10{sup 16} to 10{sup 17}/cm{sup 3}, which is mostly a surface spin density. After that we have kept the samples in liquid nitrogen for almost two years. During the two years we have used ESR to track the defect densities of the samples. The defect density increases without saturation to a value of 3 x 10{sup 19}/cm{sup 3} after two years, a number smaller than one would expect if each tritium decay were to create a silicon dangling bond (2 x 10{sup 20}/cm{sup 3}). This result suggests that there might be either an annealing process that remains at liquid nitrogen temperature, or tritium decay in clustered phase not producing a dangling bond due to bond reconstruction and emission of the hydrogen previously paired to Si-bonded tritium atom. After storage in liquid nitrogen for two years, we have annealed the samples. We have stepwise annealed one sample at temperatures up to 200, where all of the defects from beta decay are annealed out, and reconstructed the annealing energy distribution. The second sample, which was grown at 150, has

  13. Twist Defect in an Imprinted Cholesteric Elastomer

    NASA Astrophysics Data System (ADS)

    Castro-Garay, Paola; Reyes, Juan Adrian; Corella-Madueño, Adalberto

    2009-03-01

    We have found that a chiral twist defect inserted in a cholesteric elastomer gives rise to circularly polarized localized modes of both handedness. This defect enhances the resonance mode amplitude whose handedness is opposite to the cholesteric helix for high cross-linked density. Complementarily, for low cross-linked density, the circular polarization opposite to helix cholesteric of the elastomer is decoupled with the defect mode so that the resonance mode disappears . Finally, the resonance mode of the circularly polarization of the same handedness to elastomer helix is maintained either, for high or low cross-linked density.

  14. Twist defect in an imprinted cholesteric elastomer

    NASA Astrophysics Data System (ADS)

    Castro-Garay, P.; Reyes, J. Adrian; Corella-Madueño, A.

    2009-04-01

    We have found that a chiral twist defect inserted in a cholesteric elastomer gives rise to circularly polarized localized modes of both handedness. This defect enhances the resonant mode amplitude whose handedness is opposite to that of the cholesteric helix for high cross-linked density, whereas for low cross-linked density, the same mode is decoupled with the defect and thus the resonant mode disappears. Finally, the resonant mode of the same handedness as the elastomer helix is maintained for both high and low cross-linked density.

  15. 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 ...

  16. 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 ...

  17. 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 ...

  18. 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

  19. Sex ratios among infants with birth defects, National Birth Defects Prevention Study, 1997-2009.

    PubMed

    Michalski, Adrian M; Richardson, Sandra D; Browne, Marilyn L; Carmichael, Suzan L; Canfield, Mark A; VanZutphen, Alissa R; Anderka, Marlene T; Marshall, Elizabeth G; Druschel, Charlotte M

    2015-05-01

    A small number of population-based studies have examined sex differences among infants with birth defects. This study presents estimates of sex ratio for both isolated cases and those with multiple congenital anomalies, as well as by race/ethnicity. Male-female sex ratios and their 95% confidence intervals were calculated for 25,952 clinically reviewed case infants included in the National Birth Defects Prevention Study (1997-2009), a large population-based case-control study of birth defects. The highest elevations in sex ratios (i.e., male preponderance) among isolated non-cardiac defects were for craniosynostosis (2.12), cleft lip with cleft palate (2.01), and cleft lip without cleft palate (1.78); the lowest sex ratios (female preponderance) were for choanal atresia (0.45), cloacal exstrophy (0.46), and holoprosencephaly (0.64). Among isolated cardiac defects, the highest sex ratios were for aortic stenosis (2.88), coarctation of the aorta (2.51), and d-transposition of the great arteries (2.34); the lowest were multiple ventricular septal defects (0.52), truncus arteriosus (0.63), and heterotaxia with congenital heart defect (0.64). Differences were observed by race/ethnicity for some but not for most types of birth defects. The sex differences we observed for specific defects, between those with isolated versus multiple defects, as well as by race/ethnicity, demonstrate patterns that may suggest etiology and improve classification.

  20. Sex ratios among infants with birth defects, National Birth Defects Prevention Study, 1997-2009.

    PubMed

    Michalski, Adrian M; Richardson, Sandra D; Browne, Marilyn L; Carmichael, Suzan L; Canfield, Mark A; VanZutphen, Alissa R; Anderka, Marlene T; Marshall, Elizabeth G; Druschel, Charlotte M

    2015-05-01

    A small number of population-based studies have examined sex differences among infants with birth defects. This study presents estimates of sex ratio for both isolated cases and those with multiple congenital anomalies, as well as by race/ethnicity. Male-female sex ratios and their 95% confidence intervals were calculated for 25,952 clinically reviewed case infants included in the National Birth Defects Prevention Study (1997-2009), a large population-based case-control study of birth defects. The highest elevations in sex ratios (i.e., male preponderance) among isolated non-cardiac defects were for craniosynostosis (2.12), cleft lip with cleft palate (2.01), and cleft lip without cleft palate (1.78); the lowest sex ratios (female preponderance) were for choanal atresia (0.45), cloacal exstrophy (0.46), and holoprosencephaly (0.64). Among isolated cardiac defects, the highest sex ratios were for aortic stenosis (2.88), coarctation of the aorta (2.51), and d-transposition of the great arteries (2.34); the lowest were multiple ventricular septal defects (0.52), truncus arteriosus (0.63), and heterotaxia with congenital heart defect (0.64). Differences were observed by race/ethnicity for some but not for most types of birth defects. The sex differences we observed for specific defects, between those with isolated versus multiple defects, as well as by race/ethnicity, demonstrate patterns that may suggest etiology and improve classification. PMID:25711982

  1. The Effects of Defects on Melting of Copper

    NASA Astrophysics Data System (ADS)

    Han, Li-Bo; An, Qi; Luo, Sheng-Nian; Germann, Timothy C.

    2009-12-01

    With molecular dynamics (MD) simulations, we investigate the effects of defects on Cu melting under ambient pressure and shock wave loading. We explore preexistent defects including vacancies, stacking faults and grain boundaries, as well as shock-induced defects. Depending on defect characteristics (energy and concentration), defects may have negligible or considerable effects on melting at MD time and length scales. It is expected that defects have more pronounced effects at heating rates lower than the MD rates.

  2. ILT based defect simulation of inspection images accurately predicts mask defect printability on wafer

    NASA Astrophysics Data System (ADS)

    Deep, Prakash; Paninjath, Sankaranarayanan; Pereira, Mark; Buck, Peter

    2016-05-01

    At advanced technology nodes mask complexity has been increased because of large-scale use of resolution enhancement technologies (RET) which includes Optical Proximity Correction (OPC), Inverse Lithography Technology (ILT) and Source Mask Optimization (SMO). The number of defects detected during inspection of such mask increased drastically and differentiation of critical and non-critical defects are more challenging, complex and time consuming. Because of significant defectivity of EUVL masks and non-availability of actinic inspection, it is important and also challenging to predict the criticality of defects for printability on wafer. This is one of the significant barriers for the adoption of EUVL for semiconductor manufacturing. Techniques to decide criticality of defects from images captured using non actinic inspection images is desired till actinic inspection is not available. High resolution inspection of photomask images detects many defects which are used for process and mask qualification. Repairing all defects is not practical and probably not required, however it's imperative to know which defects are severe enough to impact wafer before repair. Additionally, wafer printability check is always desired after repairing a defect. AIMSTM review is the industry standard for this, however doing AIMSTM review for all defects is expensive and very time consuming. Fast, accurate and an economical mechanism is desired which can predict defect printability on wafer accurately and quickly from images captured using high resolution inspection machine. Predicting defect printability from such images is challenging due to the fact that the high resolution images do not correlate with actual mask contours. The challenge is increased due to use of different optical condition during inspection other than actual scanner condition, and defects found in such images do not have correlation with actual impact on wafer. Our automated defect simulation tool predicts

  3. 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 ...

  4. Defect Motifs for Constant Mean Curvature Surfaces

    NASA Astrophysics Data System (ADS)

    Kusumaatmaja, Halim; Wales, David J.

    2013-04-01

    The energy landscapes of electrostatically charged particles embedded on constant mean curvature surfaces are analyzed for a wide range of system size, curvature, and interaction potentials. The surfaces are taken to be rigid, and the basin-hopping method is used to locate the putative global minimum structures. The defect motifs favored by potential energy agree with experimental observations for colloidal systems: extended defects (scars and pleats) for weakly positive and negative Gaussian curvatures, and isolated defects for strongly negative Gaussian curvatures. Near the phase boundary between these regimes, the two motifs are in strong competition, as evidenced from the appearance of distinct funnels in the potential energy landscape. We also report a novel defect motif consisting of pentagon pairs.

  5. Residual Defect Density in Random Disks Deposits

    NASA Astrophysics Data System (ADS)

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

    2015-08-01

    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.

  6. Oral telangiectatic granuloma with an intrabony defect

    PubMed Central

    Rathore, Akanksha; Jadhav, Tanya; Kulloli, Anita; Singh, Archana

    2015-01-01

    Oral telangiectatic granuloma is a benign hyperplastic lesion occurring in response to trauma or chronic irritation in the oral cavity. The characteristic histological appearance comprises of typical granulation tissue with a proliferation of small thin-walled blood vessels in the loose connective tissue. We describe a case of a 36-year-old female who had a swelling in the left maxillary region which was associated with the intrabony defect. An internal bevel gingivectomy was performed, and the histopathological report was suggestive of telangiectatic granuloma. The intrabony defect was managed with the placement of platelet rich fibrin plug in the defect. A follow-up at 6 months showed no recurrence and no loss in the width of keratinized tissue. The aim of this case is to highlight the rare association of intrabony defect with telangiectatic granuloma and the need for histopathological diagnosis in such lesions. PMID:26941527

  7. 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 ...

  8. 16 CFR 1115.4 - Defect.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... example, a knife has a sharp blade and is capable of seriously injuring someone. This very sharpness, how- ever, is necessary if the knife is to function adequately. The knife does not contain a defect...

  9. 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. ...

  10. Nanometric crystal defects in transmission electron microscopy.

    PubMed

    Schäublin, Robin

    2006-05-01

    Transmission electron microscopy (TEM) is revisited in order to define methods for the identification of nanometric defects. Nanometric crystal defects play an important role as they influence, generally in a detrimental way, physical properties. For instance, radiation-induced damage in metals strongly degrades mechanical properties, rendering the material stronger but brittle. The difficulty in using TEM to identify the nature and size of such defects resides in their small size. TEM image simulations are deployed to explore limits and possible ways to improve on spatial resolution and contrast. The contrast of dislocation loops, cavities, and a stacking fault tetrahedra (SFT) are simulated in weak beam, interfering reflections (HRTEM), and scanned condensed electron probe (STEM) mode. Results indicate that STEM is a possible way to image small defects. In addition, a new objective aperture is proposed to improve resolution in diffraction contrast. It is investigated by simulations of the weak beam imaging of SFT and successfully applied in experimental observations.

  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. Di-interstitial defect in silicon revisited

    SciTech Connect

    Londos, C. A.; Antonaras, G.; Chroneos, A.

    2013-11-21

    Infrared spectroscopy was used to study the defect spectrum of Cz-Si samples following fast neutron irradiation. We mainly focus on the band at 533 cm{sup −1}, which disappears from the spectra at ∼170 °C, exhibiting similar thermal stability with the Si-P6 electron paramagnetic resonance (EPR) spectrum previously correlated with the di-interstitial defect. The suggested structural model of this defect comprises of two self-interstitial atoms located symmetrically around a lattice site Si atom. The band anneals out following a first-order kinetics with an activation energy of 0.88 ± 0.3 eV. This value does not deviate considerably from previously quoted experimental and theoretical values for the di-interstitial defect. The present results indicate that the 533 cm{sup −1} IR band originates from the same structure as that of the Si-P6 EPR spectrum.

  13. 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 ...

  14. 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 ...

  15. 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

  16. Extinction of Viral Infectivity Through Lethal Defection

    NASA Astrophysics Data System (ADS)

    Iranzo, J.; Manrubia, S. C.

    2010-04-01

    During persistent infections, selective pressure over infectivity is relaxed. In RNA viruses this results in the appearance of "parasitic" defectives, non-infective individuals that are able to take over the population causing its extinction.

  17. Phase measurements of EUV mask defects

    DOE PAGES

    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

  18. 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.

  19. 47 CFR 25.112 - Defective applications.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 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...

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. Charged local defects in extended systems

    NASA Astrophysics Data System (ADS)

    Schultz, Peter A.

    2000-03-01

    The conventional approach to treating charged defects in extended systems in first principles calculations is via the supercell approximation using a neutralizing jellium background charge. I explicitly demonstrate shortcomings of this standard appoach and show that the resulting errors in the electrostatic potential energy surface are comparable to band gaps energies, for supercell sizes typically used in defect calculations. I present an alternate scheme, generalized from the local moment counter-charge method [P.A. Schultz, Phys. Rev. B 60, 1551 (1999)], that gives the correct electrostatic potential in the vicinity of a defect, via a mixed boundary condition approach. As examples, I present results of first principles calculations for charged defects in extended systems.

  5. Surface defect inspection for power inductor

    NASA Astrophysics Data System (ADS)

    Chang, Chun-Li; Wu, Wen-Hong; Chen, Chun-Jen; Huang, Hung-Ji

    2013-06-01

    The core of the power inductor is made by powder metallurgy. By its nature, the powder-formed part has inherent nonuniform porosity pattern and parallel tool marks on the metal surface. In the past, the surface inspection of core is usually performed by using human eyes. However, the larger uncertainty of inspection will be induced while observing the defect image using human eyes. In the automated optical inspection process, the feature of defect is not easily separated from the image background by using the simple binarization method. This study develops an image processing method and employs a uniform diffuse illumination to build up a surface defect inspection system. Experiment result shows the distinguish rate is 95.5%, therefore it is clear that this system can successfully detects a set defect of the core of inductor.

  6. 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)

  7. Defect classes: An overdue paradigm for CMOS IC testing

    NASA Astrophysics Data System (ADS)

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

    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 IC's 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.

  8. Epidemiology of neural tube defects

    PubMed Central

    Seidahmed, Mohammed Z.; Abdelbasit, Omar B.; Shaheed, Meeralebbae M.; Alhussein, Khalid A.; Miqdad, Abeer M.; Khalil, Mohamed I.; Al-Enazy, Naif M.; Salih, Mustafa A.

    2014-01-01

    Objectives: To find the prevalence of neural tube defects (NTDs), and compare the findings with local and international data, and highlight the important role of folic acid supplementation and flour fortification with folic acid in preventing NTDs. Methods: This is a retrospective study of data retrieved from the medical records of live newborn infants admitted to the Neonatal Intensive Care Unit (NICU), Security Forces Hospital (SFH), Riyadh, Saudi Arabia with NTDs spanning 14 years (1996-2009). All pregnant women on their first antenatal visit to the primary care clinic were prescribed folic acid 0.5 mg daily, or 5 mg if there is a family history of NTD. The pre-fortification prevalence is compared to post-fortification, before and after excluding syndromic, genetic, and chromosomal causes. The results were compared with reports from other parts of Saudi Arabia and internationally, through a literature search using MEDLINE. Results: The prevalence of NTDs during the period was 1.2 per 1000 live births. The pre-fortification of flour with folic acid prevalence was 1.46 per 1000 live births. The post-fortification prevalence was 1.05 (p=0.103). After excluding syndromic, genetic, and chromosomal causes from calculation of the prevalence, there was a significant reduction in the prevalence, from 1.46 to 0.81 per 1000 live births (p=0.0088). Syndromic, genetic, and chromosomal causes were identified in 20 cases (19.4%). Only 2% of mothers received preconception folic acid, and only 10% of them received it during the first 4 weeks of gestation. Conclusion: Despite the implementation of fortification of flour with folic acid since 2001, the prevalence of NTDs in the Kingdom of Saudi Arabia is still high. This is due to the impact of genetic, syndromic, and chromosomal causes of NTD not preventable by folic acid. Other factors like unplanned pregnancy and lack of awareness of the role of folic acid in preventing nonsyndromic causes, play a significant role. PMID

  9. 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)

  10. 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.

  11. 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.

  12. [SOX2 defect and anophthalmia and microphthalmia].

    PubMed

    Ye, Fu-xiang; Fan, Xian-qun

    2012-11-01

    As a severe congenital developmental disorder, anophthalmia and microphthalmia are usually accompanied with vision impairment and hypoevolutism of the orbit in the affected side. Many genes are involved in anophthalmia and microphthalmia, in which, SOX2 is an important one. The defect of SOX2 causes multiple system disorders, including anophthalmia and microphthalmia. We describe the relationship between the SOX2 defect and anophthalmia/microphthalmia, in order to offer some proposals for the differential diagnosis, treatment and research of anophthalmia and microphthalmia.

  13. 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.

  14. Does thalidomide cause second generation birth defects?

    PubMed

    Smithells, D

    1998-11-01

    The proposed association between thalidomide and second generation birth defects is an improbable hypotheses which lacks, so far, any credible scientific foundation. However, the media have chosen to give it extensive coverage. So much so that even the hard-headed scientist may start wondering if there is anything in it. However, there is no reason to suppose that people with birth defects caused by exposure to thalidomide during embryonic life have any greater or lesser chance of producing children with birth defects. This appears to be the case in practice. The question could be reworded to, 'Can thalidomide be responsible for identical, or similar, birth defects in 2 generations of the same family?' For such a phenomenon to be possible, a mechanism must be proposed and there appear to be only 2 possible candidates. The first is that the defects in the parent, originating during embryonic life, have somehow been transmitted to the next generation. The second is that thalidomide is a mutagen as well as a teratogen. The first mechanism can be excluded, since Lamarckism has long since been abandoned by scientists. The hypothesis that thalidomide is a mutagen and might be responsible for birth defects in the children of thalidomide-damaged people is without any scientific foundation. Birth defects appear to be no more common amongst the children of thalidomide-affected parents than in the general population. It is important that thalidomide-affected adults are firmly reassured on this point. Most of them have now completed their own families, but they may still worry about their grandchildren. Therefore, unless and until further supportive evidence is reported by a separate and independent source, the answer to the question, 'Can thalidomide cause second generation defects?' is a very definite 'No.'

  15. 49 CFR 215.103 - Defective wheel.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Defective wheel. 215.103 Section 215.103... § 215.103 Defective wheel. A railroad may not place or continue in service a car, if— (a) A wheel flange... tread of the wheel; (b) The height of a wheel flange on the car, from the tread to the top of the...

  16. 49 CFR 215.103 - Defective wheel.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Defective wheel. 215.103 Section 215.103... § 215.103 Defective wheel. A railroad may not place or continue in service a car, if— (a) A wheel flange... tread of the wheel; (b) The height of a wheel flange on the car, from the tread to the top of the...

  17. 49 CFR 215.103 - Defective wheel.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Defective wheel. 215.103 Section 215.103... § 215.103 Defective wheel. A railroad may not place or continue in service a car, if— (a) A wheel flange... tread of the wheel; (b) The height of a wheel flange on the car, from the tread to the top of the...

  18. 49 CFR 215.103 - Defective wheel.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Defective wheel. 215.103 Section 215.103... § 215.103 Defective wheel. A railroad may not place or continue in service a car, if— (a) A wheel flange... tread of the wheel; (b) The height of a wheel flange on the car, from the tread to the top of the...

  19. 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.

  20. 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.

  1. 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.

  2. Computational defect review for actinic mask inspections

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

    As optical lithography continues to extend into low-k1 regime, resolution of mask patterns continues to diminish. The limitation of 1.35 NA posed by water-based lithography has led to the application of various resolution enhancement techniques (RET), for example, use of strong phase-shifting masks, aggressive OPC and sub-resolution assist features, customized illuminators, etc. The adoption of these RET techniques combined with the requirements to detect even smaller defects on masks due to increasing MEEF, poses considerable challenges for a mask inspection engineer. Inspecting masks under their actinic-aerial image conditions would detect defects that are more likely to print under those exposure conditions. However, this also makes reviewing such defects in their low-contrast aerial images very challenging. On the other hand, inspecting masks under higher resolution inspection optics would allow for better viewing of defects post-inspection. However, such inspections generally would also detect many more defects, including printable and nuisance, thereby making it difficult to judge which are of real concern for printability on wafer. Often, an inspection engineer may choose to use Aerial and/or high resolution inspection modes depending on where in the process flow the mask is and the specific device-layer characteristics of the mask. Hence, a comprehensive approach is needed in handling defects both post-aerial and post-high resolution inspections. This analysis system is designed for the Applied Materials Aera™ mask inspection platform, all data reported was collected using the Aera.

  3. 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).

  4. 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.

  5. 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.

  6. Defect Tolerant Semiconductors for Solar Energy Conversion.

    PubMed

    Zakutayev, Andriy; Caskey, Christopher M; Fioretti, Angela N; Ginley, David S; Vidal, Julien; Stevanovic, Vladan; Tea, Eric; Lany, Stephan

    2014-04-01

    Defect tolerance is the tendency of a semiconductor to keep its properties despite the presence of crystallographic defects. Scientific understanding of the origin of defect tolerance is currently missing. Here we show that semiconductors with antibonding states at the top of the valence band are likely to be tolerant to defects. Theoretical calculations demonstrate that Cu3N with antibonding valence band maximum has shallow intrinsic defects and no surface states, in contrast to GaN with bonding valence band maximum. Experimental measurements indicate shallow native donors and acceptors in Cu3N thin films, leading to 10(16)-10(17) cm(-3) doping with either electrons or holes depending on the growth conditions. The experimentally measured bipolar doping and the solar-matched optical absorption onset (1.4 eV) make Cu3N a promising candidate absorber for photovoltaic and photoelectrochemical solar cells, despite the calculated indirect fundamental band gap (1.0 eV). These conclusions can be extended to other materials with antibonding character of the valence band, defining a class of defect-tolerant semiconductors for solar energy conversion applications.

  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. [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.

  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. 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.

  11. 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

  12. Zero defections: quality comes to services.

    PubMed

    Reichheld, F F; Sasser, W E

    1990-01-01

    Companies that want to improve their service quality should take a cue from manufacturing and focus on their own kind of scrap heap: customers who won't come back. Because that scrap heap can be every bit as costly as broken parts and misfit components, service company managers should strive to reduce it. They should aim for "zero defections"--keeping every customer they can profitably serve. As companies reduce customer defection rates, amazing things happen to their financials. Although the magnitude of the change varies by company and industry, the pattern holds: profits rise sharply. Reducing the defection rate just 5% generates 85% more profits in one bank's branch system, 50% more in an insurance brokerage, and 30% more in an auto-service chain. And when MBNA America, a Delaware-based credit card company, cut its 10% defection rate in half, profits rose a whopping 125%. But defection rates are not just a measure of service quality; they are also a guide for achieving it. By listening to the reasons why customers defect, managers learn exactly where the company is falling short and where to direct their resources. Staples, the stationery supplies retailer, uses feedback from customers to pinpoint products that are priced too high. That way, the company avoids expensive broad-brush promotions that pitch everything to everyone. Like any important change, managing for zero defections requires training and reinforcement. Great-West Life Assurance Company pays a 50% premium to group health-insurance brokers that hit customer-retention targets, and MBNA America gives bonuses to departments that hit theirs. PMID:10107082

  13. Zero defections: quality comes to services.

    PubMed

    Reichheld, F F; Sasser, W E

    1990-01-01

    Companies that want to improve their service quality should take a cue from manufacturing and focus on their own kind of scrap heap: customers who won't come back. Because that scrap heap can be every bit as costly as broken parts and misfit components, service company managers should strive to reduce it. They should aim for "zero defections"--keeping every customer they can profitably serve. As companies reduce customer defection rates, amazing things happen to their financials. Although the magnitude of the change varies by company and industry, the pattern holds: profits rise sharply. Reducing the defection rate just 5% generates 85% more profits in one bank's branch system, 50% more in an insurance brokerage, and 30% more in an auto-service chain. And when MBNA America, a Delaware-based credit card company, cut its 10% defection rate in half, profits rose a whopping 125%. But defection rates are not just a measure of service quality; they are also a guide for achieving it. By listening to the reasons why customers defect, managers learn exactly where the company is falling short and where to direct their resources. Staples, the stationery supplies retailer, uses feedback from customers to pinpoint products that are priced too high. That way, the company avoids expensive broad-brush promotions that pitch everything to everyone. Like any important change, managing for zero defections requires training and reinforcement. Great-West Life Assurance Company pays a 50% premium to group health-insurance brokers that hit customer-retention targets, and MBNA America gives bonuses to departments that hit theirs.

  14. 40 CFR 85.1903 - Emissions defect information report.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM MOBILE SOURCES Emission Defect Reporting Requirements § 85.1903 Emissions defect information report. (a) A manufacturer shall file a defect information... 40 Protection of Environment 19 2012-07-01 2012-07-01 false Emissions defect information...

  15. 40 CFR 85.1903 - Emissions defect information report.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM MOBILE SOURCES Emission Defect Reporting Requirements § 85.1903 Emissions defect information report. (a) A manufacturer shall file a defect information... 40 Protection of Environment 19 2013-07-01 2013-07-01 false Emissions defect information...

  16. 40 CFR 85.1903 - Emissions defect information report.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM MOBILE SOURCES Emission Defect Reporting Requirements § 85.1903 Emissions defect information report. (a) A manufacturer shall file a defect information... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Emissions defect information...

  17. 40 CFR 85.1903 - Emissions defect information report.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM MOBILE SOURCES Emission Defect Reporting Requirements § 85.1903 Emissions defect information report. (a) A manufacturer shall file a defect information... 40 Protection of Environment 19 2014-07-01 2014-07-01 false Emissions defect information...

  18. 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.

  19. A novel type of developmental dentin defect.

    PubMed

    Lukinmaa, P L; Waltimo, J; Hölttä, P; Risteli, L; Risteli, J; Alaluusua, S

    1996-01-01

    We describe a developmental dentin disorder distinct from dentin defects characterized thus far. The proband was a 9-year-old boy who was the only family member known to be affected in five generations. The dental defect was not associated with any general disease or developmental disorder. The teeth appeared normal with the exception of the pink hue seen in some primary teeth. Radiographs showed pathological resorption of primary teeth and abnormally shaped pulp chambers and denticles in permanent teeth. Root canals were wide in developing teeth, but appeared thin in erupted teeth. Histological examination of two primary molars revealed canal-like defects in dentin. In the crown, the canals appeared as clusters, which alternated with columns of normal tubular dentin, and in the virtually atubular root dentin they were haphazardly distributed. Scanning electron microscopic examination confirmed the distribution pattern of the canals. In transmission electron microscopy, the defects were found to contain symmetrically banded, segmental collagenous structures. The canal contents immunostained with antibodies to the N-terminal propeptide of type I procollagen, suggesting retention of the propeptide extension in type I collagen. Whereas type III collagen reactivity was barely detectable in the canal region, staining for type V collagen and the non-fibril-forming type VI collagen was strong. The findings imply that the pathogenesis of the defect could be related to a local failure of odontoblasts to produce normal dentin matrix.

  20. Ultrasonic NDE Simulation for Composite Manufacturing Defects

    NASA Technical Reports Server (NTRS)

    Leckey, Cara A. C.; Juarez, Peter D.

    2016-01-01

    The increased use of composites in aerospace components is expected to continue into the future. The large scale use of composites in aerospace necessitates the development of composite-appropriate nondestructive evaluation (NDE) methods to quantitatively characterize defects in as-manufactured parts and damage incurred during or post manufacturing. Ultrasonic techniques are one of the most common approaches for defect/damage detection in composite materials. One key technical challenge area included in NASA's Advanced Composite's Project is to develop optimized rapid inspection methods for composite materials. Common manufacturing defects in carbon fiber reinforced polymer (CFRP) composites include fiber waviness (in-plane and out-of-plane), porosity, and disbonds; among others. This paper is an overview of ongoing work to develop ultrasonic wavefield based methods for characterizing manufacturing waviness defects. The paper describes the development and implementation of a custom ultrasound simulation tool that is used to model ultrasonic wave interaction with in-plane fiber waviness (also known as marcelling). Wavefield data processing methods are applied to the simulation data to explore possible routes for quantitative defect characterization.

  1. Molecular basis of environmentally induced birth defects.

    PubMed

    Finnell, Richard H; Waes, Janee Gelineau-van; Eudy, James D; Rosenquist, Thomas H

    2002-01-01

    Exposure of the developing conceptus to selected environmental agents can lead to deleterious and often times lethal birth defects. These malformations result in serious emotional and financial consequences to families and societies worldwide. As we continue to progress technologically, we face challenges from the introduction of new pharmacological agents and chemical compounds into the environment. This results in a concomitant need to more fully understand the relationship between in utero exposure to environmental teratogens and the risk of congenital malformations. The goal of this review is to provide a current perspective of the major concepts related to the molecular basis of environmentally induced birth defects. Starting with a discussion of commonly occurring birth defects, we consider important fundamental facets of embryonic development, teratology, and gene-environment interactions. The review then summarizes our current understanding of the molecular mechanisms involved in selected birth defects following exposure to pharmacological compounds, including thalidomide, retinoids, and valproic acid. Understanding these signaling pathways may lead to the development of safer pharmaceutical compounds and a reduction in the number of infants born with preventable birth defects.

  2. 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

  3. Defect mitigation considerations for EUV photomasks

    NASA Astrophysics Data System (ADS)

    Garetto, Anthony; Capelli, Renzo; Blumrich, Frederik; Magnusson, Krister; Waiblinger, Markus; Scheruebl, Thomas; Peters, Jan Hendrik; Goldstein, Michael

    2014-10-01

    The introduction of extreme ultraviolet (EUV) lithography into manufacturing requires changes in all aspects of the infrastructure, including the photomask. EUV reflective masks consist of a sophisticated multilayer (ML) mirror, capping layer, absorber layer, and anti-reflective coating thereby dramatically increasing the complexity of the photomask. In addition to absorber type defects similar to those the industry was forced to contend with for deep ultraviolet lithography, the complexity of the mask leads to new classes of ML defects. Furthermore, these approaches are complicated not only by the mask itself but also by unique aspects associated with the exposure of the photomask by the EUV scanner. This paper focuses on the challenges for handling defects associated with inspection, review, and repair for EUV photomasks. Blank inspection and pattern shifting, two completely new steps within the mask manufacturing process that arise from these considerations, and their relationship to mask review and repair are discussed. The impact of shadowing effects on absorber defect repair height is taken into account. The effect of mask biasing and the chief ray angle rotation due to the scanner slit arc shape will be discussed along with the implications of obtaining die-to-die references for inspection and repair. The success criteria for compensational repair of ML defects will be reviewed.

  4. 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

  5. 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

  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. Role of point defects/defect complexes in silicon device processing. Book of abstracts, fourth workshop

    SciTech Connect

    Not Available

    1994-06-01

    The 41 abstracts are arranged into 6 sessions: impurities and defects in commercial substrates: their sources, effects on material yield, and material quality; impurity gettering in silicon: limits and manufacturability of impurity gettering and in silicon solar cells; impurity/defect passivation; new concepts in silicon growth: improved initial quality and thin films; and silicon solar cell design opportunities.

  8. Reticle defect sizing of optical proximity correction defects using SEM imaging and image analysis techniques

    NASA Astrophysics Data System (ADS)

    Zurbrick, Larry S.; Wang, Lantian; Konicek, Paul; Laird, Ellen R.

    2000-07-01

    Sizing of programmed defects on optical proximity correction (OPC) feature sis addressed using high resolution scanning electron microscope (SEM) images and image analysis techniques. A comparison and analysis of different sizing methods is made. This paper addresses the issues of OPC defect definition and discusses the experimental measurement results obtained by SEM in combination with image analysis techniques.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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

    ... and Escrow and Surety Bond Against Defects Due to Defective Material and/or Faulty Workmanship. OMB... URBAN DEVELOPMENT Mortgagee's Certificate of Fees and Escrow and Surety Bond Against Defects Due to Defective Material and/or Faulty Workmanship AGENCY: Office of the Assistant Secretary for Housing,...

  14. 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...

  15. Defect Detection Using Hidden Markov Random Fields

    SciTech Connect

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

    2005-04-09

    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.

  16. Anomalous Coupling Between Topological Defects and Curvature

    NASA Astrophysics Data System (ADS)

    Vitelli, Vincenzo; Turner, Ari M.

    2004-11-01

    We investigate a counterintuitive geometric interaction between defects and curvature in thin layers of superfluids, superconductors, and liquid crystals deposited on curved surfaces. Each defect feels a geometric potential whose functional form is determined only by the shape of the surface, but whose sign and strength depend on the transformation properties of the order parameter. For superfluids and superconductors, the strength of this interaction is proportional to the square of the charge and causes all defects to be repelled (attracted) by regions of positive (negative) Gaussian curvature. For liquid crystals in the one elastic constant approximation, charges between 0 and 4π are attracted by regions of positive curvature while all other charges are repelled.

  17. Hovering black holes from charged defects

    NASA Astrophysics Data System (ADS)

    Horowitz, Gary T.; Iqbal, Nabil; Santos, Jorge E.; Way, Benson

    2015-05-01

    We construct the holographic dual of an electrically charged, localized defect in a conformal field theory at strong coupling, by applying a spatially dependent chemical potential. We find that the infrared behaviour of the spacetime depends on the spatial falloff of the potential. Moreover, for sufficiently localized defects with large amplitude, we find that a new gravitational phenomenon occurs: a spherical extremal charged black hole nucleates in the bulk: a hovering black hole. This is a second order quantum phase transition. We construct this new phase with several profiles for the chemical potential and study its properties. We find an apparently universal behaviour for the entropy of the defect as a function of its amplitude. We comment on the possible field theory implications of our results.

  18. 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

  19. 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

  20. Trapping of drops by wetting defects

    PubMed Central

    't Mannetje, Dieter; Ghosh, Somnath; Lagraauw, Rudy; Otten, Simon; Pit, Arjen; Berendsen, Christian; Zeegers, Jos; van den Ende, Dirk; Mugele, Frieder

    2014-01-01

    Controlling the motion of drops on solid surfaces is crucial in many natural phenomena and technological processes including the collection and removal of rain drops, cleaning technology and heat exchangers. Topographic and chemical heterogeneities on solid surfaces give rise to pinning forces that can capture and steer drops in desired directions. Here we determine general physical conditions required for capturing sliding drops on an inclined plane that is equipped with electrically tunable wetting defects. By mapping the drop dynamics on the one-dimensional motion of a point mass, we demonstrate that the trapping process is controlled by two dimensionless parameters, the trapping strength measured in units of the driving force and the ratio between a viscous and an inertial time scale. Complementary experiments involving superhydrophobic surfaces with wetting defects demonstrate the general applicability of the concept. Moreover, we show that electrically tunable defects can be used to guide sliding drops along actively switchable tracks—with potential applications in microfluidics. PMID:24721935

  1. Determination of defect equilibria in minerals

    NASA Astrophysics Data System (ADS)

    Hirsch, L. M.; Shankland, T. J.

    1991-01-01

    We have developed a general computation procedure DEFEQ that enables equilibrium defect concentrations in minerals to be quantitatively determined over the range of thermodynamic conditions that encompasses both laboratory experiments and Earth conditions. The governing equations are the quasichemical reactions between defects, conservation of lattice site ratios, and conservation of charge. The input parameters are the enthalpies and entropies for the defect reactions and the thermodynamic conditions which include temperature, gaseous fugacity, and chemical activities. A modified Newton-Raphson algorithm is used to simultaneously solve the nonlinear set of equations without a priori simplifications on charge balance or lattice site conservation. Our method is general and can be applied to materials other than minerals such as oxide superconductors, semiconductors, and ceramics. The method is illustrated with results from the study of (Mg,Fe)O.

  2. 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.

  3. Global defect topology in nematic liquid crystals

    NASA Astrophysics Data System (ADS)

    Machon, Thomas; Alexander, Gareth P.

    2016-07-01

    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.

  4. 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

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. Polymer-based solar cells having an active area of 1.6 cm{sup 2} fabricated via spray coating

    SciTech Connect

    Scarratt, N. W.; Griffin, J.; Zhang, Y.; Lidzey, D. G.; Wang, T.; Yi, H.; Iraqi, A.

    2015-12-01

    We demonstrate the fabrication of polymer solar cells in which both a PEDOT:PSS hole transport and a PCDTBT:PC{sub 71}BM photoactive layer are deposited by spray-casting. Two device geometries are explored, with devices having a pixel area of 165 mm{sup 2} attaining a power conversion efficiency of 3.7%. Surface metrology indicates that the PEDOT:PSS and PCDTBT:PC{sub 71}BM layers have a roughness of 2.57 nm and 1.18 nm over an area of 100 μm{sup 2}. Light beam induced current mapping reveals fluctuations in current generation efficiency over length-scales of ∼2 mm, with the average photocurrent being 75% of its maximum value.

  10. A short history of two nineteenth century German instruments at the Bologna Observatory: The 16-cm Steinheil refractor and the Ertel & Sohn meridian circle

    NASA Astrophysics Data System (ADS)

    Poppi, Francesco; Bònoli, Fabrizio; Gualandi, Andrea

    2008-07-01

    Recent work to restore and set up the materials exhibited at the Museo della Specola of the University of Bologna provided an opportunity to review the history of two important German instruments from the mid-nineteenth century, an Ertel & Sohn meridian circle and a Steinheil refractor. Purchased by the directors of the Bologna Observatory to revitalise local astronomical research, which had gradually declined over the years, both instruments have intriguing histories because, despite the fact that they were essentially underused, they also contributed to two important research projects. Lorenzo Respighi used one of them - the Ertel & Sohn meridian circle - for an experiment in physical optics related to the debate on whether light was undulatory or corpuscular, and it was essentially a forerunner of ‘water-filled telescopes’. The other, a Steinheil refractor to which a Tauber spectroscope was attached, was the largest and most important instrument used by the Italian expedition to India, organised by Pietro Tacchini to observe the transit of Venus across the Sun in 1874.

  11. The total nasal defect and reconstruction.

    PubMed

    Cannady, Steven B; Cook, Ted A; Wax, Mark K

    2009-05-01

    The structures of the nose are arguably the most complex within the face to reconstitute when absent. Total nasal reconstruction has evolved to encompass advanced surgical techniques in an effort to achieve increasingly satisfactory cosmetic results while restoring nasal function that mimics the function of a patient's natural nose. In this article, the history of total nasal defects and their reconstruction, relevant nasal anatomy, etiologies of the defect, and the surgical approaches to reconstructing each of the three-layered structure of the nose (ie, nasal skin, cartilage/bone, and lining mucosa) are explored.

  12. Interaction between a drifting spiral and defects

    SciTech Connect

    Zou, X.; Levine, H. ); Kessler, D.A. )

    1993-02-01

    Spiral waves, a type of reentrant excitation,'' are believed to be associated with the most dangerous cardiac arrhythmias, including ventricular tachycardia and fibrillation. Recent experimental findings have implicated defective regions as a means of trapping spirals which would otherwise drift and (eventually) disappear. Here, we model the myocardium as a simple excitable medium and study via simulation the interaction between a drifting spiral and one or more such defects. We interpret our results in terms of a criterion for the transition between trapped and untrapped drifting spirals.

  13. 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.

  14. Automatic leather inspection of defective patterns

    NASA Astrophysics Data System (ADS)

    Tafuri, Maria; Branca, Antonella; Attolico, Giovanni; Distante, Arcangelo; Delaney, William

    1996-02-01

    Constant and consistent quality levels in the manufacturing industry increasingly require automatic inspection. This paper describes a vision system for leather inspection based upon visual textural properties of the material surface. As visual appearances of both leather and defects exhibit a wide range of variations due to original skin characteristics, curing processes and defect causes, location and classification of defective areas become hard tasks. This paper describes a method for separating the oriented structures of defects from normal leather, a background not homogeneous in color, thickness, brightness and finally in wrinkledness. The first step requires the evaluation of the orientation field from the image of the leather. Such a field associates to each point of the image a 2D vector having as direction the dominant local orientation of gradient vectors and the length proportional to their coherence evaluated in a neighborhood of fixed size. The second step analyzes such a vector flow field by projecting it on a set of basis vectors (elementary texture vectors) spanning the vector space where the vector fields associated to the defects can be defined. The coefficients of these projections are the parameters by means of which both detection and classification can be performed. Since the set of basis vectors is neither orthogonal nor complete, the projection requires the definition of a global optimization criteria that has been chosen to be the minimum difference between the original flow field and the vector field obtained as a linear combination of the basis vectors using the estimated coefficients. This optimization step is performed through a neural network initialized to recognize a limited number of patterns (corresponding to the basis vectors). This second step estimates the parameter vector in each point of the original image. Both leather without defects and defects can be characterized in terms of coefficient vectors making it possible to

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. Variations in programmed phase defect size and its impact on defect detection signal intensity using at-wavelength inspection system

    NASA Astrophysics Data System (ADS)

    Amano, Tsuyoshi; Takagi, Noriaki; Abe, Tsukasa

    2015-10-01

    A programmed phase defect Extreme Ultraviolet (EUV) mask was fabricated and measurement repeatability of the defect size using a scanning probe microscope (SPM) was evaluated. The SPM measurement results indicated that the defect size variation as registered by the measurement repeatability were much smaller than the defect-to-defect variations. It means the defect-to-defect variation in size actually does exist. Some defects were found where their sizes before a multilayer coating (on quartz) were all the same but after the coat their sizes varied quite significantly when observed on the multilayer. This result indicated that it is difficult to estimate the phase defect size on quartz, whereas they can be accurately measured on multilayer. Influences of the defect size variation on defect detection signal intensity (DSI) using an actinic blank inspection (ABI) system were examined; their influences on the wafer printability were also examined. The DSI was strongly correlated with defect depth on the multilayer, and it was also indicated that the ABI can detect small variations in defect sizes. It was also confirmed that the impact of the phase defects on wafer printed CDs were proportional to the DSIs, and that the ABI has a potential to detect phase defect that could cause 5 % of the CD error when printing 16 nm dense lines.

  20. 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.

  1. 16 CFR 1115.4 - Defect.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... with, its design. In addition, the design of and the materials used in a consumer product may also... accordance with its design and specifications, if the design presents a risk of injury to the public. A design defect may also be present if the risk of injury occurs as a result of the operation or use of...

  2. 16 CFR 1115.4 - Defect.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... with, its design. In addition, the design of and the materials used in a consumer product may also... accordance with its design and specifications, if the design presents a risk of injury to the public. A design defect may also be present if the risk of injury occurs as a result of the operation or use of...

  3. 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

  4. 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.

  5. 9 CFR 91.30 - Defective fittings.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Defective fittings. 91.30 Section 91.30 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE EXPORTATION AND IMPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS INSPECTION AND HANDLING...

  6. 9 CFR 91.30 - Defective fittings.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Defective fittings. 91.30 Section 91.30 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE EXPORTATION AND IMPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS INSPECTION AND HANDLING...

  7. 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 EXPORTATION AND IMPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS INSPECTION AND HANDLING OF LIVESTOCK FOR EXPORTATION Inspection...

  8. 9 CFR 91.30 - Defective fittings.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Defective fittings. 91.30 Section 91.30 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE EXPORTATION AND IMPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS INSPECTION AND HANDLING...

  9. Causes of birth defects: lessons from history.

    PubMed

    Lancaster, Paul A L

    2011-03-01

    Environmental causes of birth defects have increasingly been recognized since the mid-20th century. The teratogenic effects of maternal infections such as rubella and therapeutic drugs such as thalidomide were first reported by alert clinicians. Among clinicians and researchers who have contributed significantly to our knowledge of these environmental causes, Norman Gregg was a Sydney ophthalmologist whose seminal study in 1941 identified maternal rubella as a cause of birth defects. The teratogenic effects of thalidomide were first noted in 1961 by William McBride, a Sydney obstetrician, and independently confirmed by Widukind Lenz, a German pediatrician. Marsh Edwards, an Australian veterinary scientist, showed experimentally that maternal hyperthermia caused birth defects in various animal species. While it is likely that alert individual clinicians or researchers will continue to signal the first clues about new environmental causes of birth defects, especially therapeutic drugs, it is now usually teams of laboratory researchers and epidemiologists who are more likely to provide definitive evidence of these new teratogens.

  10. [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

  11. 9 CFR 91.30 - Defective fittings.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Defective fittings. 91.30 Section 91.30 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE EXPORTATION AND IMPORTATION OF ANIMALS (INCLUDING POULTRY) AND ANIMAL PRODUCTS INSPECTION AND HANDLING...

  12. Defect characterization of silicon dendritic web ribbons

    NASA Technical Reports Server (NTRS)

    Cheng, L. J.

    1985-01-01

    Progress made in the study of defect characterization of silicon dendritic web ribbon is presented. Chemical etching is used combined with optical microscopy, as well as the electron beam induced current (EBIC) technique. Thermal annealing effect on carrier lifetime is examined.

  13. 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.

  14. 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…

  15. Defective sumoylation pathway directs congenital heart disease

    PubMed Central

    Wang, Jun; Chen, Li; Wen, Shu; Zhu, Huiping; Yu, Wei; Moskowitz, Ivan P.; Shaw, Gary M.; Finnell, Richard H.; Schwartz, Robert J

    2016-01-01

    Congenital heart defects (CHDs) are the most common of all birth defects, yet molecular mechanism(s) underlying highly prevalent atrial septal defects (ASDs) and ventricular septal defects (VSDs) have remained elusive. We demonstrate the indispensability of “balanced” post-translational SUMO conjugation-deconjugation pathway for normal cardiac development. Both hetero- and homo-zygous SUMO-1 knockout mice exhibited ASDs and VSDs with high mortality rates, which were rescued by cardiac re-expression of the SUMO-1 transgene. Since SUMO-1 was also involved in cleft lip/palate in human patients, the above findings provided a powerful rationale to question whether SUMO-1 was mutated in babies born with cleft palates and ASDs. Sequence analysis of DNA from newborn screening blood spots revealed a single 16 bp substitution in the SUMO-1 regulatory promoter of a patient displaying both oral-facial clefts and ASDs. Diminished sumoylation activity whether by genetics, environmental toxins and/or pharmaceuticals may significantly contribute to susceptibility to the induction of congenital heart disease worldwide. PMID:21563299

  16. 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.

  17. 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..., CERTIFICATION, AND STANDARDS) United States Standards for Grades for Sweet Cherries 1 Definitions § 51.2659...; including, but not limited to decayed or soft cherries and such factors as pitting, shriveling, sunken...

  18. 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...

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. 7 CFR 52.3761 - Defects.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... CERTAIN OTHER PROCESSED FOOD PRODUCTS 1 United States Standards for Grades of Canned Ripe Olives 1 Product..., blemishes, wrinkles, mutilated olives, and from any other defects which affect the appearance or edibility... ripe type or green-ripe olives which may or may not penetrate into the flesh. Olives or pieces...

  4. Optical defect modes in chiral liquid crystals

    SciTech Connect

    Belyakov, V. A.; Semenov, S. V.

    2011-04-15

    An analytic approach to the theory of optical defect modes in chiral liquid crystals (CLCs) is developed. The analytic study is facilitated by the choice of the problem parameters. Specifically, an isotropic layer (with the dielectric susceptibility equal to the average CLC dielectric susceptibility) sandwiched between two CLC layers is studied. The chosen model allows eliminating the polarization mixing and reducing the corresponding equations to the equations for light of diffracting polarization only. The dispersion equation relating the defect mode (DM) frequency to the isotropic layer thickness and an analytic expression for the field distribution in the DM structure are obtained and the corresponding dependences are plotted for some values of the DM structure parameters. Analytic expressions for the transmission and reflection coefficients of the DM structure (CLC-defect layer-CLC) are presented and analyzed for nonabsorbing, absorbing, and amplifying CLCs. The anomalously strong light absorption effect at the DM frequency is revealed. The limit case of infinitely thick CLC layers is considered in detail. It is shown that for distributed feedback lasing in a defect structure, adjusting the lasing frequency to the DM frequency results in a significant decrease in the lasing threshold. The DM dispersion equations are solved numerically for typical values of the relevant parameters. Our approach helps clarify the physics of the optical DMs in CLCs and completely agrees with the corresponding results of the previous numerical investigations.

  5. 49 CFR 215.103 - Defective wheel.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., DEPARTMENT OF TRANSPORTATION RAILROAD FREIGHT CAR SAFETY STANDARDS Freight Car Components Suspension System § 215.103 Defective wheel. A railroad may not place or continue in service a car, if— (a) A wheel flange on the car is worn to a thickness of 7/8 of an inch, or less, at a point 3/8 of an inch above...

  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. 7 CFR 52.3761 - Defects.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... to the degree of freedom from harmless extraneous vegetable material, stems, and portions thereof... the stem-flower axis. A defect is a unit where the angle of these two axes exceeds 45 degrees. (5... pitted olive equal to or exceeding the area of a circle 5 mm in diameter. (12) Stem means a stem...

  8. 7 CFR 52.3761 - Defects.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... harmless extraneous vegetable material, stems, and portions thereof, blemishes, wrinkles, mutilated olives... to olives pitted along an axis other than the stem-flower axis. A defect is a unit where the angle of.... (12) Stem means a stem that measures 3 mm or more from the shoulder of the olive. Stems are...

  9. 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.

  10. IR studies of the impact of Ge doping on the successive conversion of VO{sub n} defects in Czochralski-Si containing carbon

    SciTech Connect

    Londos, C. A.; Andrianakis, A.; Sgourou, E. N.; Emtsev, V. V.; Ohyama, H.

    2011-02-01

    We report infrared absorption studies of oxygen-related defects in electron-irradiated Ge-doped Czochralski-Si. Our investigation was mainly focused on the reaction channel leading to the formation of VO{sub n} (1{<=}n{<=}6) defects. The VO{sub n} defects form mainly upon annealing, as a result of the successive aggregation of oxygen atoms in the initial VO defect produced by the irradiation: (VO+O{sub i}{yields}VO{sub 2}+O{sub i}{yields}VO{sub 3}+O{sub i}{yields}VO{sub 4},...). It was found that the ratio of the conversion of VO{sub n} to VO{sub n+1} defects is sensitive to the Ge content of the material. In particular, the ratio of the conversion of the VO to the VO{sub 2} defects was found to decrease with the increase in Ge concentration of the samples, although the opposite trend was observed for the VO{sub 3} to VO{sub 4} conversion. However, the VO{sub 2} to VO{sub 3} conversion changes only slightly with Ge content, being practically unaffected for Ge concentrations up to 2x10{sup 20} cm{sup -3}. In the case of VO{sub 2} formation, the phenomenon was attributed to the elastic strains induced in the lattice due to the Ge presence which affects the balance between the reactions VO+O{sub i}{yields}VO{sub 2}, VO+Si{sub I}{yields}O{sub i}, mainly involved in the decay of the VO and the growth of the VO{sub 2} defects. In the case of VO{sub 4} formation, the phenomenon was discussed by taking into account the enhancement of the diffusivity of the O{sub i} atoms in the Ge-doped Si, which could lead to an enhancement of the rate of the reaction VO{sub 3}+O{sub i}{yields}VO{sub 4}. For the VO{sub 3} formation this effect is practically negligible due to the fact that at the temperatures of VO{sub 2} to VO{sub 3} conversion oxygen diffusivity is quite small. The exhibited behavior in the conversion of the VO{sub n} to VO{sub n+1} defects (n=1,2,3) was similar in Ge-doped samples with low carbon content ([C{sub s}]<2x10{sup 16} cm{sup -3}) and in Ge-doped samples with

  11. 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.

  12. 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).

  13. 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

  14. 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%).

  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. 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

  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. 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

  20. Mask defect disposition: flux-area measurement of edge, contact, and OPC defects correlates to wafer and enables effective decisions

    NASA Astrophysics Data System (ADS)

    Fiekowsky, Peter; Taylor, Darren; Wang, David; Yang, Chien-Chu; Lin, Shu-Chun; Tu, L. H.; Lin, K. R.

    2001-09-01

    Lithographers' ability to set useful defect and contact specifications has almost disappeared as chip geometries have shrunk. As features sizes have decreased, measurement error has increased to 25% of the maximum allowable defect size. This has made defect disposition so difficult that many processes now require that all detected defects be repaired because the automatic defect sizing is almost meaningless, that is, the required guard band is nearly the size of the defect specification (Reynolds, BACUS 2000). Many mask processes have abandoned defect sizingin favor of stepper simulation, either using simulation microscope, such as AIMS, or software, such as NTI's VSS. However, AVI's optical Flux-Area measurement technique provides accuracy and repeatability that gives the simple, time tested defect specification technique new life. This study demonstrates high quality edge-, contact-, and OPC- defect disposition can be achieved using the Flux-Area technique. A test mask with a range of edge defects as well as mis-sized contacts and OPC defects was written. The mask defect sizing performed with the AVI is shown to be consistent on different chips using the same process. Thus it is shown that all the over-spec defects on the wafer were measured as over-spec on the mask. Results show that edge defect size on the wafer can be accurately predicted from the AVI defect area; that printed contact size is linearly proportional to the AVI measured area, on both square and irregular contacts; and that OPC defects (printed line-end separation errors) can be accurately predicted from AVI serif-area measurements on the mask. With the Flux-Area measurement technique as implemented on the AVI Photomask Metrology System, defects can be measured with long term repeatability and rms repeatability between machines of better than 10nm, 3% of a 0.3micrometers defect. This means that guard bands can often be reduced from 0.15micrometers to below 0.05micrometers .

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. Predicting radiotherapy-induced cardiac perfusion defects

    SciTech Connect

    Das, Shiva K.; Baydush, Alan H.; Zhou Sumin; Miften, Moyed; Yu Xiaoli; Craciunescu, Oana; Oldham, Mark; Light, Kim; Wong, Terence; Blazing, Michael; Borges-Neto, Salvador; Dewhirst, Mark W.; Marks, Lawrence B.

    2005-01-01

    The purpose of this work is to compare the efficacy of mathematical models in predicting the occurrence of radiotherapy-induced left ventricular perfusion defects assessed using single-photon emission computed tomography (SPECT). The basis of this study is data from 73 left-sided breast/chestwall patients treated with tangential photon fields. The mathematical models compared were three commonly used parametric models [Lyman normal tissue complication probability (LNTCP), relative serialty (RS), generalized equivalent uniform dose (gEUD)] and a nonparametric model (Linear discriminant analysis--LDA). Data used by the models were the left ventricular dose--volume histograms, or SPECT-based dose-function histograms, and the presence/absence of SPECT perfusion defects 6 months postradiation therapy (21 patients developed defects). For the parametric models, maximum likelihood estimation and F-tests were used to fit the model parameters. The nonparametric LDA model step-wise selected features (volumes/function above dose levels) using a method based on receiver operating characteristics (ROC) analysis to best separate the groups with and without defects. Optimistic (upper bound) and pessimistic (lower bound) estimates of each model's predictive capability were generated using ROC curves. A higher area under the ROC curve indicates a more accurate model (a model that is always accurate has area=1). The areas under these curves for different models were used to statistically test for differences between them. Pessimistic estimates of areas under the ROC curve using dose-volume histogram/dose-function histogram inputs, in order of increasing prediction accuracy, were LNTCP (0.79/0.75), RS (0.80/0.77), gEUD (0.81/0.78), and LDA (0.84/0.86). Only the LDA model benefited from SPECT-based regional functional information. In general, the LDA model was statistically superior to the parametric models. The LDA model selected as features the left ventricular volumes above

  6. 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.

  7. 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.

  8. An analysis of defect densities found during software inspections

    NASA Technical Reports Server (NTRS)

    Kelly, John C.; Sherif, Joseph S.; Hops, Jonathan

    1990-01-01

    Software inspection is a technical evaluation process for finding and removing defects in requirements, design, code, and tests. Detailed data was collected during the first three years of experience at JPL on 203 inspections. Statistics are discussed for this set of inspections. Included, on a per inspection basis, are averages of: staff time expended, pages covered, major defects found, minor defects found, and inspection team size. Analysis of variance showed a significantly higher density of defects during requirements inspections. It was also observed, that the defect densities found decreased exponentially as the work products approached the coding phase. Increasing the pace of the inspection meeting decreased the density of defects found. This relationship was observed to hold for both major and minor defect densities, although it was more pronounced for minor defects. Guidelines are provided for conducting successful software inspections based upon three years of JPL experience.

  9. 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 ...

  10. 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.

  11. 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

  12. 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

  13. 24 CFR 3288.20 - Reporting a defect.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ..., manufacturer, retailer, or installer. (b) Form of report. It is recommended that alleged defects be reported in... format is required to report an alleged defect, but any such report must, at a minimum, include...

  14. Research Infusion Collaboration: Finding Defect Patterns in Reused Code

    NASA Technical Reports Server (NTRS)

    Lutz, Robyn R.; Morgan, Scott; Do, Tuan; Mikulski, Carmen; Berg Strain, Martha; Rockwell, Steve; Wilkinson, Belinda

    2004-01-01

    The 'Finding Defect Patterns in Reused Code' Research Infusion Collaboration was performed by Jet Propulsion Laboratory/Caltech under Contract 104-07-02.679 102 197 08.14.4. This final report describes the collaboration and documents the findings, including lessons learned.The research infusion collaboration characterized, using Orthogonal Defect Classification, defect reports for code that will be reused in mission-critical software on Deep Space Network Antenna controllers. Code reuse is estimated to be 90%, so it is important to identify systemic defects, or patterns, prior to reuse of this code. The work also identified ways to avoid certain types of defects and to test more efficiently.The primary objectives of the project were:to analyze defect patterns of the code to be reused based on the defects'Orthogonal Defect Classification (ODC)and to achieve a successful infusion of ODC to a project.

  15. 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.

  16. Folate metabolism and neural tube defects.

    PubMed

    Gordon, N

    1995-01-01

    Neural tube defects may due to a number of factors acting on a susceptible embryo. The most widely accepted is a lack of folic acid at a critical time of development. Studies in which folic acid supplements have been given are reviewed. The results of these support the policy of giving folic acid, starting before conception. The metabolism of folate and vitamin B12 is discussed, including specific metabolic disorders; although there is no evidence that these play any part in causing neural tube defects. The special problems that occur among women taking anti-epileptic drugs are also considered. There are slight differences in the recommendations that have been made for supplementation, and further studies are needed before there can be complete agreement. PMID:8579214

  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. Bistable defect structures in blue phase devices.

    PubMed

    Tiribocchi, A; Gonnella, G; Marenduzzo, D; Orlandini, E; Salvadore, F

    2011-12-01

    Blue phases are liquid crystals made up by networks of defects, or disclination lines. While existing phase diagrams show a striking variety of competing metastable topologies for these networks, very little is known as to how to kinetically reach a target structure, or how to switch from one to the other, which is of paramount importance for devices. We theoretically identify two confined blue phase I systems in which by applying an appropriate series of electric field it is possible to select one of two bistable defect patterns. Our results may be used to realize new generation and fast switching energy-saving bistable devices in ultrathin surface treated blue phase I wafers. PMID:22182126

  19. 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

  20. Birth defects: Risk factors and consequences.

    PubMed

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

    2013-06-01

    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. PMID:27625844

  1. 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.

  2. 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.

  3. 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

  4. Defective skeletal mineralization in pediatric CKD.

    PubMed

    Wesseling-Perry, Katherine

    2015-04-01

    Although traditional diagnosis and treatment of renal osteodystrophy focused on changes in bone turnover, current data demonstrate that abnormalities in skeletal mineralization are also prevalent in pediatric chronic kidney disease (CKD) and likely contribute to skeletal morbidities that continue to plague this population. It is now clear that alterations in osteocyte biology, manifested by changes in osteocytic protein expression, occur in early CKD before abnormalities in traditional measures of mineral metabolism are apparent and may contribute to defective skeletal mineralization. Current treatment paradigms advocate the use of 1,25(OH)2vitamin D for the control of secondary hyperparathyroidism; however, these agents fail to correct defective skeletal mineralization and may exacerbate already altered osteocyte biology. Further studies are critically needed to identify the initial trigger for abnormalities of skeletal mineralization as well as the potential effects that current therapeutic options may have on osteocyte biology and bone mineralization. PMID:25638580

  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. Masking mediated print defect visibility predictor

    NASA Astrophysics Data System (ADS)

    Jing, Xiaochen; Nachlieli, Hila; Shaked, Doron; Shiffman, Smadar; Allebach, Jan P.

    2012-01-01

    Banding is a well-known artifact produced by printing systems. It usually appears as lines perpendicular to the process direction of the print. Therefore, banding is an important print quality issue which has been analyzed and assessed by many researchers. However, little literature has focused on the study of the masking effect of content for this kind of print quality issue. Compared with other image and print quality research, our work is focused on the print quality of typical documents printed on a digital commercial printing press. In this paper, we propose a Masking Mediated Print Defect Visibility Predictor (MMPDVP) to predict the visibility of defects in the presence of customer content. The parameters of the algorithm are trained from ground-truth images that have been marked by subjects. The MMPDVP could help the press operator decide whether the print quality is acceptable for specific customer requirements. Ultimately, this model can be used to optimize the print-shop workflow.

  7. Growth and defects of explosives crystals

    NASA Astrophysics Data System (ADS)

    Cady, H. H.

    Large single crystals of PETN, RDX, and TNT can be grown easily from evaporating ethyl acetate solutions. The crystals all share a similar type of defect that may not be commonly recognized. The defect generates conical faces, ideally mosaic crystals, and may account for the 'polymorphs' of TNT and detonator grades of PETN. TATB crystals manufactured by the amination of trichlorotrinitrobenzene in dry toluene entrain two forms of ammonium chloride. One of these forms causes 'worm holes' in the TATB crystals that may be the reason for its unusually low failure diameters. Strained HMX crystals form mechanical twins that can spontaneously revert back to the untwinned form when the straining force is removed. Large strains or temperatures above 100 C lock in the mechanical twins.

  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. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. Defective skeletal mineralization in pediatric CKD.

    PubMed

    Wesseling-Perry, Katherine

    2015-04-01

    Although traditional diagnosis and treatment of renal osteodystrophy focused on changes in bone turnover, current data demonstrate that abnormalities in skeletal mineralization are also prevalent in pediatric chronic kidney disease (CKD) and likely contribute to skeletal morbidities that continue to plague this population. It is now clear that alterations in osteocyte biology, manifested by changes in osteocytic protein expression, occur in early CKD before abnormalities in traditional measures of mineral metabolism are apparent and may contribute to defective skeletal mineralization. Current treatment paradigms advocate the use of 1,25(OH)2vitamin D for the control of secondary hyperparathyroidism; however, these agents fail to correct defective skeletal mineralization and may exacerbate already altered osteocyte biology. Further studies are critically needed to identify the initial trigger for abnormalities of skeletal mineralization as well as the potential effects that current therapeutic options may have on osteocyte biology and bone mineralization.

  15. 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.

  16. Congenital skull defect and neurofibroma: without scalp and other abnormalities.

    PubMed

    Wang, Jie-Cong; Wei, Liu; Xu, Jia; Liu, Jian-Feng; Gui, Lai

    2012-07-01

    Congenital skull defect is a rare malformation that is usually associated with congenital anomalies of the scalp and comparable lesions in the brain, spinal cord, limbs, and skeletal muscle. Most previously reported cases have described skull defects with aplasia cutis congenita and other congenital abnormalities. Very few patients with skull defects present with an intact scalp or neurofibroma. The authors report an adult patient with a rare congenital skull defect and local neurofibroma.

  17. Determining corrosion defect geometry from magnetic flux leakage pig data

    SciTech Connect

    Nestleroth, J.B.; Rust, S.W.; Burgoon, D.A.; Haines, H.

    1996-08-01

    Accurate determination of the size of corrosion defects is important for determining defect severity. Many magnetic flux leakage pigs employ strong magnetizers and a large number of sensors for improved defect geometry determination methods. Analysis of data from 128 metal loss defects examined repeatedly under different test conditions is used to illustrate pig performance capabilities. An assessment of two inspection variables that can degrade performance is also presented.

  18. 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.

  19. 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.

  20. Theory of Defect Interactions in Metals.

    NASA Astrophysics Data System (ADS)

    Thetford, Roger

    Available from UMI in association with The British Library. Requires signed TDF. The static relaxation program DEVIL has been updated to use N-body Finnis-Sinclair potentials. Initial calculations of self-interstitial and monovacancy formation energies confirm that the modified program is working correctly. An extra repulsive pair potential (constructed to leave the original fitting unaltered) overcomes some deficiencies in the published Finnis-Sinclair potentials. The modified potentials are used to calculate interstitial energies and relaxations in the b.c.c. transition metals vanadium, niobium, tantalum, molybdenum and tungsten. Further adaptation enables DEVIL to model dislocations running parallel to any lattice vector. Periodic boundary conditions are applied in the direction of the dislocation line, giving an infinite straight dislocation. The energies per unit length of two different dislocations are compared with experiment. A study of migration of point defects in the perfect lattice provides information on the mobility of interstitials and vacancies. The possible reorientation of split dumbbell interstitials in a migration step comes under scrutiny. The total energy needed to form and migrate an interstitial is compared with that required for a vacancy. The interaction between point defects and dislocations is studied in detail. Binding energies for both self-interstitials and monovacancies at edge dislocations are calculated for the five metals mentioned above. Formation energies of the point defects in the neighbourhood of the edge dislocation are calculated for niobium, and the extent of the regions from which the defects are spontaneously absorbed are found. For split dumbbell interstitials, the size and shape of the absorption region depends on the orientation of the dumbbell. Migration of both interstitials and vacancies into the absorption zone is studied; the presence of the dislocation has a particularly dramatic effect on vacancy migration. The

  1. 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

  2. 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.

  3. 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.

  4. Defects of the Glycinergic Synapse in Zebrafish.

    PubMed

    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

  5. 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.

  6. 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

  7. [Hereditary defects in artificially-inseminated breeds].

    PubMed

    Müller, F

    1994-10-01

    Since it is possible to analyse genes directly and thus decipher the genome, animal hereditary diseases are in the centre of attention again. This publication presents some selected genetically determined illnesses and points out to the significance of monogene disorders with recessive genetic pathway particularly. By using genetic engineering, e.g. PCR, significant progress can be made in the diagnosis of genetic defects. But it is necessary to find ways of dealing with them. PMID:7855849

  8. 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

  9. 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.}

  10. 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.

  11. Defect energy levels from current transient recording

    NASA Astrophysics Data System (ADS)

    Momayezi, Michael

    1991-07-01

    Silicon detectors are widely used in high energy physics in vertexing and calorimetry applications. The radiative environment will introduce defects with energy levels in the bandgap into the crystals. At the high levels of radiation present at proton accelerators the defect concentration will easily approach or exceed the doping concentration of the usual high ohmic material. DLTS, the most common technique for defect characterization is known to fail under these conditions. To study heavy radiation damage in silicon detectors a new method has been developed. Using a DLTS-like pulser setup, the current transient from trap emptying is recorded on a fast digital scope being read out by a microcomputer. This is repeatedly done during a temperature scan. The time integral of the current transient equals the number of traps present and the activation enthalpy is found from the temperature dependence of the emission life time. If there is more than one energy level present the individual components may be extracted by a fitting procedure from the then multiexponential current transient. The sensitivity reached so far is, noise and systematics considered, ˜10 9 traps. Lifetimes between 5 μs and 5 ms are covered.

  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. 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.

  14. 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

  15. 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.

  16. 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.

  17. Perfluorooctanoate exposure and major birth defects.

    PubMed

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

    2014-08-01

    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 to 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

  18. 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.

  19. 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

  20. Defect reduction methodologies: pellicle yield improvement

    NASA Astrophysics Data System (ADS)

    Daugherty, Susan V.

    1993-03-01

    The pelliclization process at Intel during the first half of 1991 was not in control. Weekly process yield was trending downward, and the range of the weekly yield during that time frame was greater than 40%. A focused effort in process yield improvement, that started in the second half of 1991 and continued through 1992, brought process yield up an average of 20%, and reduced the range of the process yield to 20 - 25%. This paper discusses the continuous process improvement guidelines that are being followed to reduce variations/defects in the pelliclization process. Teamwork tools, such as Pareto charts, fishbone diagrams, and simple experiments, prioritize efforts and help find the root cause of the defects. Best known methods (BKM), monitors, PMs, and excursion control aid in the elimination and prevention of defects. Monitoring progress and repeating the whole procedure are the final two guidelines. The benefits from the use of the continuous process improvement guidelines and tools can be seen in examples of the actions, impacts, and results for the last half of 1991 and the first half of 1992.

  1. 21 CFR 1003.2 - Defect in an electronic product.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 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...

  2. 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

  3. Molecular motors are stymied by microtubule lattice defects

    NASA Astrophysics Data System (ADS)

    Gramlich, Michael

    2014-03-01

    The microtubule surface provides the tracks that molecular motors use to transport cargo throughout the cell. Much like any surface lattice, the microtubule surface may have surface defects such as dislocations or step edges caused by missing tubulin dimers or shifts in the number of protofilaments, respectively. It is an open question as to how microtubule lattice defects affect molecular motors walking along microtubule surfaces. We used the kinesin-1 motor that walks along a single protofilament and has a short step size of only 8 nm to test how lattice defects affect transport. We created microtubule lattice defects by end-to-end annealing microtubules with different protofilament numbers and differential fluorescence labeling, creating a transition in microtubule radius at the annealed site that is directly visualizable. Surprisingly, we observed that kinesin-1 motors are significantly inhibited by protofilament shift defects. GFP-tagged kinesin-1 motors detach at the defect site during at least 70% of encounters with the defect. We find end-to-end annealed microtubules without the additional change in protofilament number at the defect site inhibit at least 50% of kinesin-1 motors at the defect, suggesting that the process of end-to-end annealing creates defects within the lattice. Our results imply that defects within the microtubule lattice can inhibit motility, and must be corrected. Our work sheds light on the biological importance of removing and correcting lattice defects, an activity known to occur by multiple methods in cells.

  4. Nondestructive evaluation of weld defects by infrared thermography

    SciTech Connect

    Satonaka, Shinobu; Ohba, Hiroyasu; Shinozaki, Kenya

    1995-12-31

    In order to clarify the applicability of infrared thermography to the nondestructive evaluation of weld defects, an infrared measurement was conducted on the welds with various artificial defects. Two heating methods, a moving gas flame and a Joule effect by electric current flow, were used for the fast and large area inspection with readily interpretable images of defects. Finite element analysis was also used for the theoretical analyses of beat conduction and electric current flow, together with the development of imaging technique for the evaluation of the shape and size of defects. As the results of infrared measurements and theoretical analyses, the selection of heating method and the acquisition of infrared images were important for the clear image and precise measurement of weld defects. As for the clear images, the Joule effect heating was useful for the detection of open-to-the-surface defects, while the moving gas flame heating was available to the inner defect parallel to the surface. It was also clarified that the types of defects were identified by the distribution of high and low temperature regions. In the measurement of defect size, defect edges were evaluated by the positions with maximum temperature gradient in the moving gas flame heating, and with minimum second derivative of temperature in the Joule effect heating. The effective images for the precise measurement of defect size were obtained from the ones immediately after current flow in the Joule effect heating, and just before the arrival of gas flame beneath the defect.

  5. 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.

  6. 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).

  7. 7 CFR 52.808 - Freedom from defects.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Freedom from defects. 52.808 Section 52.808... Quality § 52.808 Freedom from defects. (a) General. The factor of freedom from defects refers to the degree of freedom from harmless extraneous material, mutilated cherries, and cherries blemished by...

  8. 7 CFR 51.2280 - Tolerances for grade defects.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Tolerances for grade defects Total defects Serious damage Very serious damage Shell and foreign material U. S... 7 Agriculture 2 2010-01-01 2010-01-01 false Tolerances for grade defects. 51.2280 Section 51.2280... STANDARDS) United States Standards for Shelled English Walnuts (Juglans Regia) Tolerances for Grade...

  9. 7 CFR 51.1439 - Tolerances for defects.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Tolerances for defects. 51.1439 Section 51.1439... STANDARDS) United States Standards for Grades of Shelled Pecans Tolerances for Defects § 51.1439 Tolerances for defects. In order to allow for variations incident to proper grading and handling in each of...

  10. 7 CFR 51.2280 - Tolerances for grade defects.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Tolerances for grade defects Total defects Serious damage Very serious damage Shell and foreign material U. S... 7 Agriculture 2 2011-01-01 2011-01-01 false Tolerances for grade defects. 51.2280 Section 51.2280... STANDARDS) United States Standards for Shelled English Walnuts (Juglans Regia) Tolerances for Grade...

  11. 7 CFR 51.1439 - Tolerances for defects.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Tolerances for defects. 51.1439 Section 51.1439... STANDARDS) United States Standards for Grades of Shelled Pecans Tolerances for Defects § 51.1439 Tolerances for defects. In order to allow for variations incident to proper grading and handling in each of...

  12. 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

  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... Standards for Grades of Cantaloups 1 Definitions § 51.494c Condition defects. Condition defects means... soft cantaloups and such factors as liquid in the seed cavity, surface mold, sunken areas, fresh...

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. 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

  19. Defects in silicene: vacancy clusters, extended line defects, and Di-adatoms.

    PubMed

    Li, Shuang; Wu, Yifeng; Tu, Yi; Wang, Yonghui; Jiang, Tong; Liu, Wei; Zhao, Yonghao

    2015-01-26

    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 sp(2)/sp(3) 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.

  20. 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... or Defective Cost or Pricing Data. As prescribed in 1615.407-1, the following clause shall be... or Pricing Data (JAN 2004) (a) If any rate established in connection with this contract was...

  1. 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... or Defective Cost or Pricing Data. As prescribed in 1615.407-1, the following clause shall be... or Pricing Data (JAN 2004) (a) If any rate established in connection with this contract was...

  2. 48 CFR 1652.215-70 - 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. 1652.215-70 Section 1652.215-70 Federal Acquisition... or Defective Cost or Pricing Data. As prescribed in 1615.407-1, the following clause shall be... or Pricing Data (JAN 2004) (a) If any rate established in connection with this contract was...

  3. Stressed states and persistent defects in confined nematic elastica

    NASA Astrophysics Data System (ADS)

    Köpf, M. H.; Pismen, L. M.

    2015-10-01

    We analyse the variety of solutions, both defect-free and containing defects in a confined nematic elastomer, arising as a result of competition between nematic ordering and elastic stresses. Phase field analysis predicts bifurcation of solutions with symmetric and antisymmetric distribution of nematic alignment from a perfectly aligned stressed state. The antisymmetric branch always has a lower energy, as confirmed by numerical computations away from the bifurcation point. At still higher deviations, states containing persistent defect pairs become preferable but defect-free states and states with defects coexist in a wide parametric range.

  4. Nanoscale analysis of defect shedding from liquid crystal interfaces.

    PubMed

    Wincure, Benjamin M; Rey, Alejandro D

    2007-06-01

    A new defect-forming mechanism is predicted for liquid crystals undergoing an isotropic-to-nematic phase transition. A continuum theory characterizes how +1/2 defects (D<30 nm) evolve within and then shed from the interface (cross section approximately 100 nm) of a growing 5CB (4-n-4'-pentyl-4-cyanobiphenyl) nanodroplet (20 nmdefect core shapes, and the evolving defect core structure are presented at the nanoscale to better understand liquid crystal anisotropy and orientation during interfacial defect shedding.

  5. 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.

  6. 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.

  7. Defect depth measurement of carbon fiber reinforced polymers by thermography

    NASA Astrophysics Data System (ADS)

    Chen, Terry Y.; Chen, Jian-Lun

    2016-01-01

    Carbon fiber reinforced polymers has been widely used in all kind of the industries. However the internal defects can result in the change of material or mechanical properties, and cause safety problem. In this study, step-heating thermography is employed to measure the time series temperature distribution of composite plate. The principle of heat conduction in a flat plate with defect inside is introduced. A temperature separation criterion to determine the depth of defect inside the specimen is obtained experimentally. Applying this criterion to CFRP specimens with embedded defects, the depth of embedded defect in CFRP can be determined quite well from the time series thermograms obtained experimentally.

  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. Defects' geometric feature recognition based on infrared image edge detection

    NASA Astrophysics Data System (ADS)

    Junyan, Liu; Qingju, Tang; Yang, Wang; Yumei, Lu; Zhiping, Zhang

    2014-11-01

    Edge detection is an important technology in image segmentation, feature extraction and other digital image processing areas. Boundary contains a wealth of information in the image, so to extract defects' edges in infrared images effectively enables the identification of defects' geometric features. This paper analyzed the detection effect of classic edge detection operators, and proposed fuzzy C-means (FCM) clustering-Canny operator algorithm to achieve defects' edges in the infrared images. Results show that the proposed algorithm has better effect than the classic edge detection operators, which can identify the defects' geometric feature much more completely and clearly. The defects' diameters have been calculated based on the image edge detection results.

  10. Reconstruction of malunited diaphyseal fractures of the forearm.

    PubMed

    Jayakumar, Prakash; Jupiter, Jesse B

    2014-09-01

    The forearm is a complex anatomical and functional unit with unique osseous, soft tissue and articular relationships. Disruption of these important relations can have a significant impact, leading to pain, instability of the radio-ulnar articulation and reduced range of motion. The gold standard for treating forearm fractures in adults remains anatomic reduction, stable plate fixation and preservation of the surrounding blood supply. Failure to achieve these goals may lead to malunion, requiring reconstructive surgery, which can be technically challenging. In this review, we discuss the essential aspects of anatomy and pathomechanics, clinical and radiological assessment and the state of the art in pre-operative planning and deformity correction surgery.

  11. Application of DBM tool for detection of EUV mask defect

    NASA Astrophysics Data System (ADS)

    Yoo, Gyun; Kim, Jungchan; Park, Chanha; Lee, Taehyeong; Ji, Sunkeun; Yang, Hyunjo; Yim, Donggyu; Park, Byeongjun; Maruyama, Kotaro; Yamamoto, Masahiro

    2013-04-01

    Extreme ultraviolet lithography (EUVL) is one of the most leading lithography technologies for high volume manufacturing. The EUVL is based on reflective optic system therefore critical patterning issues are arisen from the surface of photomask. Defects below and inside of the multilayer or absorber of EUV photomask is one of the most critical issues to implement EUV lithography in mass production. It is very important to pick out and repair printable mask defects. Unfortunately, however, infrastructure for securing the defect free photomask such as inspection tool is still under development furthermore it does not seem to be ready soon. In order to overcome the lack of infrastructures for EUV mask inspection, we will discuss an alternative methodology which is based on wafer inspection results using DBM (Design Based Metrology) tool. It is very challenging for metrology to quantify real mask defect from wafer inspection result since various sources are possible contributor. One of them is random defect comes from poor CD uniformity. It is probable that those random defects are majority of a defect list including real mask defects. It is obvious that CD uniformity should be considered to pick out only a real mask defect. In this paper, the methodology to determine real mask defect from the wafer inspection results will be discussed. Experiments are carried out on contact layer and on metal layer using mask defect inspection tool, Teron(KLA6xx) and DBM (Design Based Metrology) tool, NGR2170™.

  12. 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.

  13. 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.

  14. Defective TFH Cell Function and Increased TFR Cells Contribute to Defective Antibody Production in Aging.

    PubMed

    Sage, Peter T; Tan, Catherine L; Freeman, Gordon J; Haigis, Marcia; Sharpe, Arlene H

    2015-07-14

    Defective antibody production in aging is broadly attributed to immunosenescence. However, the precise immunological mechanisms remain unclear. Here, we demonstrate an increase in the ratio of inhibitory T follicular regulatory (TFR) cells to stimulatory T follicular helper (TFH) cells in aged mice. Aged TFH and TFR cells are phenotypically distinct from those in young mice, exhibiting increased programmed cell death protein-1 expression but decreased ICOS expression. Aged TFH cells exhibit defective antigen-specific responses, and programmed cell death protein-ligand 1 blockade can partially rescue TFH cell function. In contrast, young and aged TFR cells have similar suppressive capacity on a per-cell basis in vitro and in vivo. Together, these studies reveal mechanisms contributing to defective humoral immunity in aging: an increase in suppressive TFR cells combined with impaired function of aged TFH cells results in reduced T-cell-dependent antibody responses in aged mice.

  15. Extreme Ultraviolet Multilayer Defect Compensation in Computational Lithography.

    PubMed

    Kim, Sang-Kon

    2016-05-01

    For the extreme ultraviolet (EUV) lithography, multilayer (ML) defects such as bump and pit defects can disrupt the phase of reflected field and degrade aerial images on wafer. In this paper, a defect printability and repair simulator (DPRS) is introduced to predict and repair the effect of ML defects in EUV aerial images. DPRS is composed of multilayer growth by using Gaussian function and Stearns's method, mask simulation by using a scattering matrix (S-matrix) analysis method, and projection simulation by using Köhler's illumination. For bump and pit ML defects, the combining the modified absorber and the layer-by-layer ML peeling is better than other methods. This study can be helpful in understanding EUV defect and also give insight into the EUV defect compensation for the device volume production. PMID:27483941

  16. 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

  17. 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.

  18. 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.

  19. Native defects in Tl6SI4: Density functional calculations

    DOE PAGES

    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

  20. 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.