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Sample records for modular titanium endoprosthesis

  1. Lower limb salvage surgery: modular endoprosthesis in bone tumour treatment.

    PubMed

    Orlic, D; Smerdelj, M; Kolundzic, R; Bergovec, M

    2006-12-01

    We retrospectively analysed 90 patients who underwent "en bloc" resection and modular endoprosthesis reconstruction in the lower limbs between 1987-2003. After proximal femur resection, reconstruction was performed with a modular endoprosthesis by Howmedica (KFTR, designed by Kotz) and modular revision endoprosthesis by W. Link or Lima-Lto (Revision system, designed by Wagner). The knee joint was reconstructed with a modular endoprosthesis (Howmedica, KFTR designed by Kotz) after distal femur or proximal tibia resection. Malignant bone tumours were present in 58 patients (64.5%), benign tumours in 16 (17.8%), metastases in 8 (8.9%), tumour-like lesions in 4 (4.4 %) and non-tumour-related destruction of the femur in 4 patients (4.4%). High-grade tumours were found in the majority of malignant bone tumours (70.7%). Treatment complications, which occurred in 26 patients, were: local recurrence of the tumour, deep infection, acetabular destruction following hemiarthroplasty, recurrent dislocations of endoprosthesis, periprosthetic fracture and hardware problems. In total, 23 patients (25.6%) died due to tumours. Endoprostheses should be considered as a treatment of choice for bone tumours in the hip and knee joint region. Advances in limb salvage surgery are, and will long continue to be, a great challenge for orthopaedic oncologists of the 21st century.

  2. Fatigue - corrosion of endoprosthesis titanium alloys.

    PubMed

    Cornet, A; Muster, D; Jaeger, J H

    1979-01-01

    Commercial total hip prostheses often show certain metallurgical faults (porosities, coarse grains, growth dendrites, carbide networks). In order to investigate more accurately the role played by these different parameters in prostheses failure we performed a large number of systematic corrosion, fatigue and fatigue - corrosion tests on these materials and on commercial total hip prostheses. Ultimate strengthes seem to be reached for cast cobalt alloys, whereas titanium alloys, such as Ta 6 V, present very high fatigue limit under corrosion. Thus, rotative bending fatigue - corrosion tests in biological environment provide values about 50 DaN/mm2. This value, is nevertheless appreciably higher than those obtained with stellites and stainless steel. Titanium alloys, because of their mechanical performances, their weak Young's modulus (11000 DaN/mm2) and their relative lightness (4.5. g/cm3), which are associated with a good biocompatibility, seem very promising for permanent implants realisation.

  3. Surgical difficulties encountered with use of modular endoprosthesis for limb preserving salvage of failed allograft reconstruction after malignant tumor resection.

    PubMed

    Foo, Leon S S; Hardes, Jendrik; Henrichs, Marcel; Ahrens, Helmut; Gosheger, Georg; Streitbürger, Arne

    2011-08-01

    We reviewed outcomes and discussed surgical difficulties encountered in 10 patients who had modular endoprosthesis for limb preserving salvage of failed allograft reconstruction after malignant tumor resection. Mean allograft survival time before failure was 127.4 months (range, 14-264 months). Mean length of follow-up since endoprosthesis revision surgery was 62.8 months (range, 16-132 months). There was one endoprosthesis failure, resulting in a mean endoprosthesis survival time of 56.9 months (range, 16-132). Complications included arterial laceration, nerve injury, periprosthetic crack fracture, aseptic loosening, and infection. Modular endoprosthesis remain a viable option that should be considered in any limb preserving salvage of failed allograft reconstructions. However, altered anatomy, poor/short remnant host bone, periprosthetic fractures, inadequate soft tissue coverage and infection remain important difficulties encountered.

  4. Effect of postoperative radiation therapy on mandibular reconstruction using a modular endoprosthesis - a pilot study.

    PubMed

    Lye, Kok Weng; Chin, Francis Kuok Choon; Tideman, Henk; Merkx, Matthias A W; Jansen, John A

    2013-09-01

    The endoprosthetic system has been shown to be a potential option for mandibular reconstruction. The objective of this pilot in vivo animal study was to determine the effects of postoperative radiation using brachytherapy on bone and soft tissue healing in mandibles reconstructed with the endoprosthesis. Six adult Macaca fascicularis mandibles were reconstructed with a cemented endoprosthesis after segmental body resection. The animals were divided into two groups. The test group was subjected to radiation therapy 1 month postoperation while the control group did not receive any radiation. Results showed no major radiation side effects. Mucosal ulcerations and wound dehiscence at the radiated sites healed within 4 weeks. One animal from each group had prosthesis failure and was unable to complete the study. Micro-CT findings indicated no significant differences between the total bone volume percentage (TBV%) of the study and control groups. Histomorphometrical analysis using grading scales also showed no significant differences between the two groups. Under the study conditions, postoperative brachytherapy did not affect the tissue response around the endoprosthesis within the early 6 months postradiation period. The endoprosthesis, therefore, remains a viable reconstructive option when postoperative radiation is prescribed. Copyright © 2012 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  5. Loss of distal femur combined with popliteal artery occlusion: reconstructive arthroplasty using modular segmental endoprosthesis: a case report.

    PubMed

    Kang, Shin-Taeg; Hwang, Chan-Ha; Kim, Bo-Hyeon; Sung, Byung-Yoon

    2009-04-01

    Severe injury to the knee and the surrounding area is frequently associated with injury to ligaments of the knee joint and structures in the popliteal fossa. This case involved a popliteal artery occlusion, severe bone loss of distal femur, loss of collateral ligaments, and extensor mechanism destruction of the knee. Initially, prompt recognition and correction of associated popliteal artery injury are important for good results after treatment. After successful revascularization, treatment for severe bone loss of distal femur and injury of the knee joint must be followed. We treated this case by delayed reconstruction using modular segmental endoprosthesis after revascularization of the popliteal artery. This allowed early ambulation. At 36 months after surgery, the patient had good circulation of the lower limb and was ambulating independently.

  6. Elevated Serum Titanium Level as a Marker for Failure in a Titanium Modular Fluted Tapered Stem.

    PubMed

    McAlister, Ian P; Abdel, Matthew P

    2016-07-01

    Serum ion concentrations of cobalt and chromium are commonly used to monitor for the development of local metal reactions in metal-on-metal total hip arthroplasties, as well as dual-modular constructs. Although rarely used in clinical practice, elevated serum titanium levels have the ability to indicate a failure with contemporary revision constructs, such as with titanium modular fluted tapered (TMFT) stems. The authors report the case of a 64-year-old man with a TMFT stem after revision total hip arthroplasty for a dual-modular neck construct who had set screw disengagement with subsequent proximal body loosening. The patient's serum cobalt and chromium levels were normal, but he had a markedly elevated serum titanium level, indicating failure of the titanium modular junction. Implant failures at modular junctions in femoral components are well described. Although several different failure mechanisms have been defined, to the authors' knowledge this is the first reported failure of this particular TMFT stem. In addition, this is the first report describing the use of serum titanium levels in identifying a novel failure mechanism. With the popularity of this stem, surgeons should be aware that an elevated serum titanium level may aid in the diagnosis of this unique complication. [Orthopedics. 2016; 39(4):e768-e770.].

  7. Corrosion behavior of tantalum-coated cobalt-chromium modular necks compared to titanium modular necks in a simulator test.

    PubMed

    Dorn, Ulrich; Neumann, Daniel; Frank, Mario

    2014-04-01

    This study compared the corrosion behavior of tantalum-coated cobalt-chromium modular necks with that of titanium alloy modular necks at their junction to titanium-alloy femoral stem. Tests were performed in a dry assembly and two wet assemblies, one contaminated with calf serum and the other contaminated with calf serum and bone particles. Whereas the titanium modular neck tested in the dry assembly showed no signs of corrosion, the titanium modular necks tested in both wet assemblies showed marked depositions and corrosive attacks. By contrast, the tantalum-coated cobalt-chromium modular necks showed no traces of corrosion or chemical attack in any of the three assemblies. This study confirms the protective effect of tantalum coating the taper region of cobalt-chromium modular neck components, suggesting that the use of tantalum may reduce the risk of implant failure due to corrosion. © 2014.

  8. Endoprosthesis and Obesity

    PubMed Central

    Grubor, Predrag; Manojlovic, Slavko; Manojlovic, Nemanja; Grubor, Milan

    2013-01-01

    ABSTRACT Introduction: Obesity represents a significant risk factor in the pathophysiology of degenerative changes in coxarthrosis. Objective: The study aims to investigate obesity as a risk factor in the examined sample comprising 136 patients who underwent hip endoprothesis implantation. Material and methods: The series comprised 136 patients with a hip endoprosthesis implanted, where the patients’ BMI, amount of blood used, duration of surgery, number of assistants, and type of anaesthesia were observed. Wounds and late post-operative complications, infections, haemorrhage, vein thrombosis, endoprosthesis dislocations, length of inpatient stay, start of physical therapy and full weight-bearing were also observed. The observation period lasted six months on average. Discussion: In simple terms, the three greatest factors when implanting a hip endoprosthesis are as follows: properties of the endoprosthesis, the orthopaedic surgeon’s skill and experience, and individual characteristics of the patient, i.e. age, sex, health condition, body weight, BMI, adequate physical therapy. Conclusion: We believe that the implantation of a hip endoprosthesis should be postponed for patients with a BMI exceeding 29.99. Such patients should receive endocrine treatment, they should undergo a weight loss programme in order to reduce their body weight and in order to reduce their BMI to under 29.99. PMID:25568519

  9. In vivo severe corrosion and hydrogen embrittlement of retrieved modular body titanium alloy hip-implants.

    PubMed

    Rodrigues, Danieli C; Urban, Robert M; Jacobs, Joshua J; Gilbert, Jeremy L

    2009-01-01

    Titanium alloys are widely used in total-joint replacements due to a combination of outstanding mechanical properties, biocompatibility, passivity, and corrosion resistance. Nevertheless, retrieval studies have pointed out that these materials can be subjected to localized or general corrosion in modular interfaces when mechanical abrasion of the oxide film (fretting) occurs. Modularity adds large crevice environments, which are subject to micromotion between contacting interfaces and differential aeration of the surface. Titanium alloys are also known to be susceptible to hydrogen absorption, which can induce precipitation of hydrides and subsequent brittle failure. In this work, the surface of three designs of retrieved hip-implants with Ti-6Al-4V/Ti-6Al-4V modular taper interfaces in the stem were investigated for evidence of severe corrosion and precipitation of brittle hydrides during fretting-crevice corrosion in the modular connections. The devices were retrieved from patients and studied by means of scanning electron microscopy (SEM), X-ray diffraction (XRD), and chemical analysis. The surface qualitative investigation revealed severe corrosion attack in the mating interfaces with evidence of etching, pitting, delamination, and surface cracking. In vivo hydrogen embrittlement was shown to be a mechanism of degradation in modular connections resulting from electrochemical reactions induced in the crevice environment of the tapers during fretting-crevice corrosion.

  10. IN VIVO SEVERE CORROSION AND HYDROGEN EMBRITTLEMENT OF RETRIEVED MODULAR BODY TITANIUM ALLOY HIP-IMPLANTS

    PubMed Central

    Rodrigues, Danieli C.; Urban, Robert M.; Jacobs, Joshua J.; Gilbert, Jeremy L.

    2009-01-01

    Titanium alloys are widely used in total-joint replacements due to a combination of outstanding mechanical properties, biocompatibility, passivity and corrosion resistance. Nevertheless, retrieval studies have pointed out that these materials can be subjected to localized or general corrosion in modular interfaces when mechanical abrasion of the oxide film (fretting) occurs. Modularity adds large crevice environments, which are subject to micromotion between contacting interfaces and differential aeration of the surface. Titanium alloys are also known to be susceptible to hydrogen absorption, which can induce precipitation of hydrides and subsequent brittle failure. In this work, the surface of three designs of retrieved hip-implants with Ti-6Al-4V/Ti-6Al-4V modular taper interfaces in the stem were investigated for evidence of severe corrosion and precipitation of brittle hydrides during fretting-crevice corrosion in the modular connections. The devices were retrieved from patients and studied by means of scanning electron microscopy (SEM), x-ray diffraction (XRD) and chemical analysis. The surface qualitative investigation revealed severe corrosion attack in the mating interfaces with evidence of etching, pitting, delamination and surface cracking. In vivo hydrogen embrittlement was shown to be a mechanism of degradation in modular connections resulting from electrochemical reactions induced in the crevice environment of the tapers during fretting-crevice corrosion. PMID:18683224

  11. Modular titanium alloy neck adapter failures in hip replacement - failure mode analysis and influence of implant material

    PubMed Central

    2010-01-01

    Background Modular neck adapters for hip arthroplasty stems allow the surgeon to modify CCD angle, offset and femoral anteversion intraoperatively. Fretting or crevice corrosion may lead to failure of such a modular device due to high loads or surface contamination inside the modular coupling. Unfortunately we have experienced such a failure of implants and now report our clinical experience with the failures in order to advance orthopaedic material research and joint replacement surgery. The failed neck adapters were implanted between August 2004 and November 2006 a total of about 5000 devices. After this period, the titanium neck adapters were replaced by adapters out of cobalt-chromium. Until the end of 2008 in total 1.4% (n = 68) of the implanted titanium alloy neck adapters failed with an average time of 2.0 years (0.7 to 4.0 years) postoperatively. All, but one, patients were male, their average age being 57.4 years (36 to 75 years) and the average weight 102.3 kg (75 to 130 kg). The failures of neck adapters were divided into 66% with small CCD of 130° and 60% with head lengths of L or larger. Assuming an average time to failure of 2.8 years, the cumulative failure rate was calculated with 2.4%. Methods A series of adapter failures of titanium alloy modular neck adapters in combination with a titanium alloy modular short hip stem was investigated. For patients having received this particular implant combination risk factors were identified which were associated with the occurence of implant failure. A Kaplan-Meier survival-failure-analysis was conducted. The retrieved implants were analysed using microscopic and chemical methods. Modes of failure were simulated in biomechanical tests. Comparative tests included modular neck adapters made of titanium alloy and cobalt chrome alloy material. Results Retrieval examinations and biomechanical simulation revealed that primary micromotions initiated fretting within the modular tapered neck connection. A continuous

  12. Modular titanium alloy neck adapter failures in hip replacement--failure mode analysis and influence of implant material.

    PubMed

    Grupp, Thomas M; Weik, Thomas; Bloemer, Wilhelm; Knaebel, Hanns-Peter

    2010-01-04

    Modular neck adapters for hip arthroplasty stems allow the surgeon to modify CCD angle, offset and femoral anteversion intraoperatively. Fretting or crevice corrosion may lead to failure of such a modular device due to high loads or surface contamination inside the modular coupling. Unfortunately we have experienced such a failure of implants and now report our clinical experience with the failures in order to advance orthopaedic material research and joint replacement surgery.The failed neck adapters were implanted between August 2004 and November 2006 a total of about 5000 devices. After this period, the titanium neck adapters were replaced by adapters out of cobalt-chromium. Until the end of 2008 in total 1.4% (n = 68) of the implanted titanium alloy neck adapters failed with an average time of 2.0 years (0.7 to 4.0 years) postoperatively. All, but one, patients were male, their average age being 57.4 years (36 to 75 years) and the average weight 102.3 kg (75 to 130 kg). The failures of neck adapters were divided into 66% with small CCD of 130 degrees and 60% with head lengths of L or larger. Assuming an average time to failure of 2.8 years, the cumulative failure rate was calculated with 2.4%. A series of adapter failures of titanium alloy modular neck adapters in combination with a titanium alloy modular short hip stem was investigated. For patients having received this particular implant combination risk factors were identified which were associated with the occurRence of implant failure. A Kaplan-Meier survival-failure-analysis was conducted. The retrieved implants were analysed using microscopic and chemical methods. Modes of failure were simulated in biomechanical tests. Comparative tests included modular neck adapters made of titanium alloy and cobalt chrome alloy material. Retrieval examinations and biomechanical simulation revealed that primary micromotions initiated fretting within the modular tapered neck connection. A continuous abrasion and

  13. Oldest biliary endoprosthesis in situ

    PubMed Central

    Consolo, Pierluigi; Scalisi, Giuseppe; Crinò, Stefano F; Tortora, Andrea; Giacobbe, Giuseppa; Cintolo, Marcello; Familiari, Luigi; Pallio, Socrate

    2013-01-01

    The advantages of endoscopic retrograde cholangiopancreatography over open surgery have made it the predominant method of treating patients with choledocholithiasis. After sphincterotomy, however, 10%-15% of common bile duct stones cannot be removed with a basket or balloon. The methods for managing “irretrievable stones” include surgery, mechanical lithotripsy, intraductal or extracorporeal shock wave lithotripsy and biliary stenting. The case presented was a referred 82-year-old Caucasian woman with a 7-year-old plastic biliary endoprosthesis in situ. To the best of our knowledge the examined endoprosthesis is the oldest endoprosthesis in situ reported in the literature. Endoscopic biliary endoprosthesis placement remains a simple and safe procedure for patients with stones that are difficult to manage by conventional endoscopic methods and for patients who are unfit for surgery or who are high surgical risks. To date no consensus has been reached regarding how long a biliary prosthesis should remain in situ. Long-term biliary stenting may have a role in selected elderly patients if stones extraction has failed because the procedure may prevent stones impaction and cholangitis. PMID:23858381

  14. Biological response on a titanium implant-grade surface functionalized with modular peptides☆

    PubMed Central

    Yazici, H.; Fong, H.; Wilson, B.; Oren, E.E.; Amos, F.A.; Zhang, H.; Evans, J.S.; Snead, M.L.; Sarikaya, M.; Tamerler, C.

    2015-01-01

    Titanium (Ti) and its alloys are among the most successful implantable materials for dental and orthopedic applications. The combination of excellent mechanical and corrosion resistance properties makes them highly desirable as endosseous implants that can withstand a demanding biomechanical environment. Yet, the success of the implant depends on its osteointegration, which is modulated by the biological reactions occurring at the interface of the implant. A recent development for improving biological responses on the Ti-implant surface has been the realization that bifunctional peptides can impart material binding specificity not only because of their molecular recognition of the inorganic material surface, but also through their self-assembly and ease of biological conjugation properties. To assess peptide-based functionalization on bioactivity, the present authors generated a set of peptides for implant-grade Ti, using cell surface display methods. Out of 60 unique peptides selected by this method, two of the strongest titanium binding peptides, TiBP1 and TiBP2, were further characterized for molecular structure and adsorption properties. These two peptides demonstrated unique, but similar molecular conformations different from that of a weak binder peptide, TiBP60. Adsorption measurements on a Ti surface revealed that their disassociation constants were 15-fold less than TiBP60. Their flexible and modular use in biological surface functionalization were demonstrated by conjugating them with an integrin recognizing peptide motif, RGDS. The functionalization of the Ti surface by the selected peptides significantly enhanced the bioactivity of osteoblast and fibroblast cells on implant-grade materials. PMID:23159566

  15. Are titanium-on-titanium TiAl6V4 modular necks safe in total hip arthroplasty for non-overweight patients? Results of a prospective series at a minimum follow-up of 7 years.

    PubMed

    Ollivier, Matthieu; Parratte, Sébastien; Galland, Alexandre; Lunebourg, Alexandre; Argenson, Jean-Noel

    2015-10-01

    Using extramedullar modularity in total hip arthroplasty has been proposed as an option to optimize the restoration of hip biomechanics. To avoid the problems that were observed with cobalt-chrome modular neck, titanium modular necks have been developed. The goals of our study were to evaluate the safety of titanium-on-titanium TiAl6V4 modular neck system. Hundred patients with a mean age of 69.6 ± 10.6 (42-86 years) and mean BMI of 25.07 ± 4.86 (17-38 kg/m(2)) suffering from primary or secondary arthritis of the hip were prospectively included. At a minimum of 7 years, no fracture of the modular neck was observed. No patient required a revision. No sign of loosening was found in the radiological analysis. Our study shows that titanium-on-titanium TiAl6V4 modular neck system can safely be used with good midterm clinical and radiological results for non-overweight patients. These results should be confirmed at longer follow-up.

  16. Modular titanium alloy neck failure in total hip replacement: analysis of a relapse case.

    PubMed

    Ceretti, Marco; Falez, Francesco

    2016-04-29

    Modular neck hip prosthesis born in the 1990 with the aim of allowing the surgeon to modify CCD angle, offset and femoral anteversion intra-operatively restoring patient's original biomechanics. In order to achieve the best biomechanics of the reconstructed hip, preoperative planning is essential. In the last few years modularity has been questioned and an argument made for the return to mono block stems due to events of breakage or disconnection of modular components. Fretting or crevice corrosion may lead to failure of such modular device due to the contamination inside the modular coupling or to high loads. We present a case of repetitive modular femoral neck prosthesis fracture.

  17. The Effect of Taper Angle and Spline Geometry on the Initial Stability of Tapered, Splined Modular Titanium Stems.

    PubMed

    Pierson, Jeffery L; Small, Scott R; Rodriguez, Jose A; Kang, Michael N; Glassman, Andrew H

    2015-07-01

    Design parameters affecting initial mechanical stability of tapered, splined modular titanium stems (TSMTSs) are not well understood. Furthermore, there is considerable variability in contemporary designs. We asked if spline geometry and stem taper angle could be optimized in TSMTS to improve mechanical stability to resist axial subsidence and increase torsional stability. Initial stability was quantified with stems of varied taper angle and spline geometry implanted in a foam model replicating 2cm diaphyseal engagement. Increased taper angle and a broad spline geometry exhibited significantly greater axial stability (+21%-269%) than other design combinations. Neither taper angle nor spline geometry significantly altered initial torsional stability.

  18. Modular titanium alloy neck failure in total hip replacement: analysis of a relapse case

    PubMed Central

    Ceretti, Marco; Falez, Francesco

    2016-01-01

    Modular neck hip prosthesis born in the 1990 with the aim of allowing the surgeon to modify CCD angle, offset and femoral anteversion intra-operatively restoring patient’s original biomechanics. In order to achieve the best biomechanics of the reconstructed hip, preoperative planning is essential. In the last few years modularity has been questioned and an argument made for the return to mono block stems due to events of breakage or disconnection of modular components. Fretting or crevice corrosion may lead to failure of such modular device due to the contamination inside the modular coupling or to high loads. We present a case of repetitive modular femoral neck prosthesis fracture. PMID:27163109

  19. [Damage to a hip endoprosthesis caused by high-frequency electrocautery].

    PubMed

    Huber, G; Weik, T; Morlock, M M

    2009-07-01

    Contact between high-frequency cauterising instruments and metal endoprostheses can cause visible flashovers. The resulting local heating might partially transform the microstructure of the prostheses. In the present case a flashover to the in situ titanium hip endoprosthesis during the revision of a fractured ceramic head decreased the fatigue strength of the prosthesis and ultimately caused its failure. During revision surgery it is essential to prevent contact between in situ metal components and high-frequency cauterising instruments.

  20. Migration of the Nellix endoprosthesis.

    PubMed

    England, Andrew; Torella, Francesco; Fisher, Robert K; McWilliams, Richard G

    2016-08-01

    This study reports the incidence and sequelae of migration of the Nellix (Endologix Inc, Irvine, Calif) endoprosthesis after endovascular aneurysm sealing. A review was performed of the follow-up imaging of all endovascular aneurysm sealing patients in a university hospital endovascular program who had a minimum follow-up of 1 year. The first postoperative and latest follow-up computed tomography scans were used to measure the distances between the proximal and distal borders of the stent grafts relative to reference vessels using a previously validated technique. Device migration was based on previously established criteria and defined as any stent graft movement of ≥4 mm related to a predefined reference vessel. Device movement in a caudal direction was given a positive value, and movement in a cranial direction was denoted by a negative value. Eighteen patients (35 stent grafts) were eligible for inclusion in this retrospective review. The mean preoperative abdominal aortic aneurysm diameter was 57 mm (standard deviation [SD], 5; range, 50-67 mm) and aortic neck length was 30 mm (SD, 16; range, 6-62 mm). Proximal migration, according to study definitions, was identified in six stent grafts (17%), all in a caudal direction. At 1 year the mean proximal migration distance was +6.6 mm (SD, 1.6; range, +4.7-+9.2 mm). Migration occurred in a single stent graft in four patients and bilaterally in one. No distal migration occurred. Proximal migration of the Nellix endoprosthesis does occur and was without any sequelae in our series. Further investigations into the long-term positional stability of the Nellix device, together with a more thorough understanding of the etiology and consequences of migration, are required. Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

  1. The influence of contact conditions and micromotions on the fretting behavior of modular titanium alloy taper connections.

    PubMed

    Baxmann, M; Jauch, S Y; Schilling, C; Blömer, W; Grupp, T M; Morlock, M M

    2013-05-01

    Modularity of femoral stems and neck components has become a more frequently used tool for an optimized restoration of the hip joint center and improvement of patient biomechanics. The additional taper interface increases the risk of mechanical failure due to fretting and crevice corrosion. Several failures of titanium alloy neck adapters have been documented in case-reports. An experimental fretting device was developed in this study to systematically investigate the effect of micromotion and contact pressure on fretting damage in contact situations similar to taper interfaces of modular hip prostheses under cyclic loading representative of in vivo load conditions. As a first application, the fretting behavior of Ti-6Al-4V titanium alloy components was investigated. Micromotions were varied between 10μm and 50μm, maximum contact pressures between 400 and 860N/mm(2). All modes of fretting damage were observed: Fretting wear was found for high micromotions in combination with low contact pressures. Fretting fatigue occurred with reduced movement or increased contact pressures. With small micromotions or high normal pressures, low fretting damage was observed. The developed device can be used to evaluate taper design (and especially contact geometry) as well as different materials prior to clinical use.

  2. Titanium

    SciTech Connect

    Fox, G.J.

    1997-01-01

    The article contains a summary of factors pertinent to titanium use. Geology and exploitation, production processes, global production, titanium dioxide and alloy applications, and the titanium market are reviewed. Potential applications outlined are for oil and gas equipment and for the automotive industry. Titanium alloys were selected for drilling risers for North Sea oil and gas drilling platforms due to a high strength-to-weight ratio and corrosion resistance. These properties also make titanium alloys attractive for auto parts, although the cost is currently prohibitive.

  3. Titanium

    USGS Publications Warehouse

    Bedinger, G.M.

    2013-01-01

    Titanium is the ninth most abundant element in the earth’s crust and can be found in nearly all rocks and sediments. It is a lithophile element with a strong affinity for oxygen and is not found as a pure metal in nature. Titanium was first isolated as a pure metal in 1910, but it was not until 1948 that metal was produced commercially using the Kroll process (named after its developer, William Kroll) to reduce titanium tetrachloride with magnesium to produce titanium metal.

  4. Nitrogen diffusion-hardened titanium-6aluminum-4vanadium alloy surfaces in modular hip prostheses

    NASA Astrophysics Data System (ADS)

    Venugopalan, Ramakrishna

    In vitro galvanic corrosion testing of static cobalt alloy (CoCrMo) and titanium alloy (Ti64) couples illustrated that galvanic stimulus was not large enough to initiate accelerated corrosion at this interface. Analyses of explanted prostheses revealed that instances of accelerated corrosion were associated with areas of prior mechanical and could not be attributed to galvanic origin. Hence, any attempt at improving the performance of this CoCrMo/Ti64 alloy couple would have to center around controlling the resistance to mechanical damage of this mixed-metal interface, specifically the Ti64 alloy components, as the CoCrMo alloy already possesses superior tribological properties. Subsequently, the effect of a nitrogen diffusion hardening process on the surface morphology, chemistry, microhardness, and corrosion resistance of Ti64 alloy was determined. Surface morphology was analyzed using scanning probe microscopy. Diffusion hardened titanium alloy samples (N-Ti64) exhibited a more pronounced grain structure, less distinct machining grooves, increasingly nodular surface, and significantly higher Rsb{a} and RMS values compared to the Ti64 samples. The electrochemical behavior of the N-Ti64 and Ti64 sample groups were equivalent. The Vicker's microhardness values of the N-Ti64 alloy were 2.5 times and 1.5 times greater than the Ti64 and CoCrMo samples, respectively. The change in surface composition and chemistry was analyzed using Auger electron and X-ray photoelectron spectroscopy. The effect of nitrogen diffusion hardening was apparent to a depth of 40 nm. N-Ti64 samples exhibited the presence of TiN/TiNO on the immediate surface and sub-surface layers and also a significant increase in the oxygen concentration profile compared to Ti64 alloy samples This increase in oxide thickness was confirmed using electrochemical impedance spectroscopy (EIS). EIS analyses also resulted in a deterministic bilayer oxide (porous outer oxide and barrier inner oxide) model for the

  5. Posttraumatic pancreatic fistula cured by endoprosthesis in the pancreatic duct.

    PubMed

    Fabre, J M; Bauret, P; Prudhomme, M; Quenet, F; Noel, P; Baumel, H; Michel, H; Domergue, J

    1995-05-01

    We report a case of pancreatic fistula attributable to posttraumatic rupture of the main duct that was undiagnosed before ERCP and was cured instantaneously by endoscopic placement of an endoprosthesis in the pancreatic duct after failure of conventional medical treatment.

  6. New lumbar disc endoprosthesis applied to the patient's anatomic features.

    PubMed

    Mróz, Adrian; Skalski, Konstanty; Walczyk, Wojciech

    2015-01-01

    The paper describes the process of designing, manufacturing and design verification of the intervertebral of a new structure of lumbar disc endoprosthesis - INOP/LSP.1101. Modern and noninvasive medical imagining techniques, make it possible to record results of tests in a digital form, which creates opportunities for further processing. Mimics Innovation Suite software generates three-dimensional virtual models reflecting the real shape and measurements of components of L4-L5 spinal motion segment. With the use of 3D Print technique, physical models of bone structures of the mobile segment of the spine as well as the INOP/LSP.1101 endoprosthesis model were generated. A simplified FEA analysis of stresses in the endoprosthesis was performed to evaluate the designed geometries and materials of the new structure. The endoprosthesis prototype was made of Co28Cr6Mo alloy with the use of selective laser technology. The prototypes were subject to tribological verification with the use of the SBT-03.1 spine simulator. The structure of the endoprosthesis ensures a full reflection of its kinematics, full range of mobility of the motion segment in all anatomical planes as well as restoration of a normal height of the intervertebral space and curvature of the lordosis. The results of the tribological tests confirmed that SLM technology has the potential for production of the human bone and jointendoprostheses.

  7. Hardening Effect Analysis by Modular Upper Bound and Finite Element Methods in Indentation of Aluminum, Steel, Titanium and Superalloys.

    PubMed

    Bermudo, Carolina; Sevilla, Lorenzo; Martín, Francisco; Trujillo, Francisco Javier

    2017-05-19

    The application of incremental processes in the manufacturing industry is having a great development in recent years. The first stage of an Incremental Forming Process can be defined as an indentation. Because of this, the indentation process is starting to be widely studied, not only as a hardening test but also as a forming process. Thus, in this work, an analysis of the indentation process under the new Modular Upper Bound perspective has been performed. The modular implementation has several advantages, including the possibility of the introduction of different parameters to extend the study, such as the friction effect, the temperature or the hardening effect studied in this paper. The main objective of the present work is to analyze the three hardening models developed depending on the material characteristics. In order to support the validation of the hardening models, finite element analyses of diverse materials under an indentation are carried out. Results obtained from the Modular Upper Bound are in concordance with the results obtained from the numerical analyses. In addition, the numerical and analytical methods are in concordance with the results previously obtained in the experimental indentation of annealed aluminum A92030. Due to the introduction of the hardening factor, the new modular distribution is a suitable option for the analysis of indentation process.

  8. Hardening Effect Analysis by Modular Upper Bound and Finite Element Methods in Indentation of Aluminum, Steel, Titanium and Superalloys

    PubMed Central

    Bermudo, Carolina; Sevilla, Lorenzo; Martín, Francisco; Trujillo, Francisco Javier

    2017-01-01

    The application of incremental processes in the manufacturing industry is having a great development in recent years. The first stage of an Incremental Forming Process can be defined as an indentation. Because of this, the indentation process is starting to be widely studied, not only as a hardening test but also as a forming process. Thus, in this work, an analysis of the indentation process under the new Modular Upper Bound perspective has been performed. The modular implementation has several advantages, including the possibility of the introduction of different parameters to extend the study, such as the friction effect, the temperature or the hardening effect studied in this paper. The main objective of the present work is to analyze the three hardening models developed depending on the material characteristics. In order to support the validation of the hardening models, finite element analyses of diverse materials under an indentation are carried out. Results obtained from the Modular Upper Bound are in concordance with the results obtained from the numerical analyses. In addition, the numerical and analytical methods are in concordance with the results previously obtained in the experimental indentation of annealed aluminum A92030. Due to the introduction of the hardening factor, the new modular distribution is a suitable option for the analysis of indentation process. PMID:28772914

  9. [Joint endoprosthesis pathology. Histopathological diagnostics and classification].

    PubMed

    Krenn, V; Morawietz, L; Jakobs, M; Kienapfel, H; Ascherl, R; Bause, L; Kuhn, H; Matziolis, G; Skutek, M; Gehrke, T

    2011-05-01

    Prosthesis durability has steadily increased with high 10-year rates of 88-95%. However, four pathogenetic groups of diseases can decrease prosthesis durability: (1) periprosthetic wear particle disease (aseptic loosening) (2) bacterial infection (septic loosening) (3) periprosthetic ossification, and (4) arthrofibrosis. The histopathological "extended consensus classification of periprosthetic membranes" includes four types of membranes, arthrofibrosis, and osseous diseases of endoprosthetics: The four types of neosynovia are: wear particle-induced type (type I), mean prosthesis durability (MPD) in years 12.0; infectious type (type II), MPD 2.5; combined type (type III) MPD 4.2; and indeterminate type (type IV), MPD 5.5. Arthrofibrosis can be determined in three grades: grade 1 needs clinical information to be differentiated from a type IV membrane, and grades 2 & 3 can be diagnosed histopathologically. Periprosthetic ossification, osteopenia-induced fractures, and aseptic osteonecrosis can be histopathologically diagnosed safely with clinical information. The extended consensus classification of periprosthetic membranes may be a diagnostic groundwork for a future national endoprosthesis register.

  10. Modular endoprosthetic reconstruction in malignant bone tumors: indications and limits.

    PubMed

    Balke, Maurice; Ahrens, Helmut; Streitbürger, Arne; Gosheger, Georg; Hardes, Jendrik

    2009-01-01

    Modular tumor prostheses are well established today for the reconstruction of osseous defects after resection of malignant bone tumors. Almost every joint and even total bones (e.g., total femur or humerus) can be replaced with promising functional results, dramatically reducing the need for ablative procedures. Although the complication rate with the use of modern modular endoprostheses is constantly decreasing, the need for revision surgery is still significantly higher than in primary joint arthroplasty. In this review we present the modular endoprosthesis system developed in our institution, summarize the postoperative management, and discuss the indications, limits, and complications as well as the functional results.

  11. Amplatz Thrombectomy Device: Unexpected Interaction with the Cragg Endoprosthesis

    SciTech Connect

    Schwarzenberg, Helmut; Mueller-Huelsbeck, Stefan; Heller, Martin

    1998-01-15

    In a 74-year-old woman, a Dacron-covered Cragg endoprosthesis was implanted into the left superficial femoral artery after successful recanalization of a 6-cm-long occlusion. At 4.5 months after discharge the endoprosthesis was occluded. In order to perform a thrombectomy, an Amplatz thrombectomy device (ATD) was activated and advanced into the occluded graft. Suddenly, a mechanical failure of the ATD occurred. Extraction of the ATD was achieved only after repeated attempts at rotating motion and jerky pullback maneuvers. The most likely explanation is that one of the graft-struts had advanced into the tip of the ATD and resulted in a broken drive shaft. Recanalization was completed by performing percutaneous transluminal angioplasty and pharmacological thrombolysis with recombinant human-tissue plasminogen activator. In conclusion, users of the ATD have to be aware of interactions of the ATD with the struts of implanted stents or grafts during thrombectomy.

  12. [Particle disease--aseptic loosening of the total hip endoprosthesis].

    PubMed

    Kolundzić, Robert; Orlić, Dubravko

    2008-01-01

    Total hip arthroplasty (THA) improves the ability and quality of life in patients with hip dysfunction due to different causes. Aseptic loosening is the major cause of the late hip endoprosthesis failure. It results from aseptic inflammatory reaction induced by the implant wear debris accumulating at the prosthesis interface, and is mediated by numerous cellular and humoral factors. Due to presence of wear debris we call aseptic loosening of the total hip endoprosthesis as "particle disease". In the most important of factors affecting the risk of aseptic instability include patient's age, sex, body mass index, underlying morbidity (reason for THA), endoprosthetic material and surgeon's skill. However, taken together, all these factors explain only a minor part of variability of this phenomenon. Factors that are decisive for the occurrence of aseptic instability are still largely unknown. The existence of "individual disposition" for development of aseptic instability that is not determined by demographic or biomechanical factors is well recognized.

  13. Self-expanding wallstent endoprosthesis for malignant ureteral obstruction.

    PubMed

    Díaz-Lucas, E F; Martínez-Torres, J L; Fernández Mena, J; Carazo Martínez, O; de la Fuente Serrano, A; Zuluaga Gómez, A

    1997-12-01

    We present our experience with the self-expanding Wallstent endoprosthesis for ureteral recanalization in obstructive uropathy secondary to malignant pelvic disease. In total, 19 stents were inserted in 14 ureters. The follow-up included 100% of the patients. To date, except for one case, the patency of the stent has always persisted for the period of the survival of the patients, the longest ones being 4 and 4.1 years.

  14. A NEW APPROACH TO PARTIALKNEE ENDOPROSTHESIS IN PRIMARY BONE SARCOMAS

    PubMed Central

    Penna, Valter; Toller, Eduardo Areas; Pinheiro, Carla; Becker, Ricardo Gehrke

    2015-01-01

    Partial knee endoprosthesis to bone sarcomas resections seems to be a good solution to treat this immature skeletal patients. The purpose of this study is to evaluate the functional score in fourteen patients, advantages and the technique indications. Methods: Retrospective analysis was done to assess in this group of patients the functional evolution and the possible complications of the procedure. 14 patients between 10 and 22 years functionally evaluated in Ennekin/ISOLS (International Society of Limb Salvage) criteria, being all of them operated in the same institution by the same surgeon. Were used distal femur and proximal tibia partial endoprosthesis. Results: General analysis demonstrated that the functional results were over than 67 percent (ISOLS criteria) in 78,6 percent of the patients, being considered excellent. 21,4 percent were considered good results, being between 50 and 66 percent. Bone storage was preserved when avoiding the adjacent segment resection. Surgery time was not prolonged in ligament reconstruction. Conclusion: Knee partial endoprosthesis are less damage to bone storage in young patients. The critics about the bad functional results are being supplied by new surgical techniques, excellent rehabilitation protocols, implants technology and the consequent learning curve. This option of treatment permits the preservation of healthy bone and provides the possibility of a revision replacement less aggressive. PMID:26998452

  15. [Long-term results of endoprosthesis of the hip joint with Plus-Endoprosthetic prosthesis].

    PubMed

    Neverov, V A; Kurbanov, S Kh; Serb, S K

    2011-01-01

    An experience and results with using endoprosthesis of the hip joint with Plus-Endoprosthetic prosthesis in 937 (1018 operations) patients were analyzed. The period of follow-up observations was 12 years. Distinctive characteristics of the endoprosthesis are described. Specific behavior of this construction in patients with diseases and damages of the hip joint are shown. Results and complications of the endoprosthesis operations are analyzed. In whole, excellent and good results were obtained in 99.42% of cases, satisfactory - in 0.47%, unsatisfactory - in 0.11%.

  16. Initial experience with a newly developed cementless hip endoprosthesis.

    PubMed

    Hach, V; Delfs, G

    2009-01-01

    The HELICA-Endoprosthesis is a newly developed cementless hip prosthesis for dogs. It was implanted in 39 dogs that had severe hip osteoarthritis and a history of hip pain, as well as in one dog that had chronic hip luxation. One dog had a bilateral arthroplasty. The body weight of the patients ranged between 22 and 54 kg and their ages between nine months and 10 years. Both the femoral stem and acetabular component of the prosthesis were screwed into position following bony preparation. Additional fixation was not necessary as the components remain fixed in position until osteointegration is complete. There are currently five sizes of prosthesis available, and the various components such as the stem, cup and head are readily interchangeable. Although it appeared that good osseous anchorage of the prostheses in the bone on the surgery table had been obtained, three patients experienced both stem and cup loosening (one week, three weeks and six months after surgery). In one animal, stem loosening was observed six weeks after surgery, and another dog experienced a cup loosening two weeks postoperatively. Most of the complications were due to technical errors that occurred during the learning phase. Surgical revisions were successful in three out of five animals. In two animals we had to perform a femoral head and neck excision. Two other animals experienced radiographic bone resorption underneath the segmented collar of the femoral prosthesis but did not show any significant clinical signs of lameness. Another dog that showed signs of ischial neuropraxy after surgery, recovered completely within six weeks after surgery. All of the dogs were capable of weight bearing on the operated leg one day after surgery. The main advantage of the HELICA-Endoprosthesis is the relatively easy surgical technique and short surgery time. The initial clinical results in these 40 cases have been very encouraging. The aim of this study was to assess the early clinical results in these 39

  17. Proximal humeral replacement using a fixed-fulcrum endoprosthesis.

    PubMed

    Griffiths, D; Gikas, P D; Jowett, C; Bayliss, L; Aston, W; Skinner, J; Cannon, S; Blunn, G; Briggs, T W R; Pollock, R

    2011-03-01

    Between 1997 and 2007, 68 consecutive patients underwent replacement of the proximal humerus for tumour using a fixed-fulcrum massive endoprosthesis. Their mean age was 46 years (7 to 87). Ten patients were lost to follow-up and 16 patients died. The 42 surviving patients were assessed using the Musculoskeletal Tumor Society (MSTS) Score and the Toronto Extremity Salvage Score (TESS) at a mean follow-up of five years and 11 months (one year to ten years and nine months). The mean MSTS score was 72.3% (53.3% to 100%) and the mean TESS was 77.2% (58.6% to 100%). Four of 42 patients received a new constrained humeral liner to reduce the risk of dislocation. This subgroup had a mean MSTS score of 77.7% and a mean TESS of 80.0%. The dislocation rate for the original prosthesis was 25.9; none of the patients with the new liner had a dislocation at a mean of 14.5 months (12 to 18). Endoprosthetic replacement for tumours of the proximal humerus using this prosthesis is a reliable operation yielding good results without the documented problems of unconstrained prostheses. The performance of this prosthesis is expected to improve further with a new constrained humeral liner, which reduces the risk of dislocation.

  18. Reactivation of a tuberculous coxitis due to loosening of a total hip endoprosthesis.

    PubMed

    Fink, B; Casser, H R; Zilkens, K W; Rüther, W

    1995-01-01

    A 45-year-old woman who suffered from juvenile tuberculous coxitis at the age of 4 is presented. Her hip joint replacement lasted for 18 years and then needed replacing. Intraoperatively removed caseous soft tissue and an opalescent secretion histologically resembled a tuberculous focus, and bacteriological culture grew a Mycobacterium tuberculosis strain. Four months after the replacement, the patient suffered from a tuberculosis-induced septic loosening of the newly replaced hip joint endoprosthesis. The tuberculosis relapse was probably due to aseptic loosening of the first hip joint endoprosthesis.

  19. Spontaneous re-expansion of a collapsed thoracic endoprosthesis: case report.

    PubMed

    Pontón, Alejandro; García, Iván; Arnáiz, Elena; Bernal, José M

    2008-12-01

    A 43-year-old woman with a type B aortic dissection underwent insertion of a Zenith stent graft (Cook Inc, Bloomington, Ind). Chest pain developed 36 hours after the procedure. A computed tomography scan showed reopening of the false proximal lumen and almost complete device collapse. Because of hemodynamic stability and absence of signs of malperfusion, the patient was treated conservatively. A control computed tomography scan 7 days later showed full re-expansion of the endoprosthesis. This case illustrates that in extremely rare cases, spontaneous reexpansion of a collapsed thoracic endoprosthesis can occur after conservative management.

  20. [Study on design method for the individual anatomical hip joint endoprosthesis].

    PubMed

    Gong, Xiansheng; Kang, Liyun; Wang, Jian

    2008-02-01

    To solve the problem of aseptic loosening of hip joint prosthesis after THR (total hip replacement) and to meet the requirement of individual endoprosthesis for rapid automatic design and manufacture, a new method is presented. According to the anatomical shape of the patient's femoral marrow cavity and the replacement requirement, the hip joint prosthesis is designed via the combination of medical CT technique, computer aided design and finite element analysis. During analysis of the endoprosthesis, the 3-D finite element model of the femur is structured by finite element software ANSYS, the near true femoral material parameters are gained, the quantitative description of femoral material's anisotropy and inhomogeneity is realized by self-developed specific software in the 3-D finite element model of femur. Contact analyses of the customized hip endoprosthesis--femur system are simulated by ANSYS, stress, strain and their distribution are analyzed and contrasted before and after-operation under the action of physiological load in the system. It is feasible to checkout the rationality of the design by comparing the stress distribution in the femur with the situation before replacement, the extent of stress-shielding caused by the replacement is determined quantificationally. The results reveal that the method is more reasonable and reliable and can provide basic means for optimizing the design of custom-made hip prostheses and for evaluating the long-term stability of endoprosthesis after operation.

  1. Modular entanglement.

    PubMed

    Gualdi, Giulia; Giampaolo, Salvatore M; Illuminati, Fabrizio

    2011-02-04

    We introduce and discuss the concept of modular entanglement. This is the entanglement that is established between the end points of modular systems composed by sets of interacting moduli of arbitrarily fixed size. We show that end-to-end modular entanglement scales in the thermodynamic limit and rapidly saturates with the number of constituent moduli. We clarify the mechanisms underlying the onset of entanglement between distant and noninteracting quantum systems and its optimization for applications to quantum repeaters and entanglement distribution and sharing.

  2. Malignant biliary obstruction complicated by ascites: Closure of the transhepatic tract with cyanoacrylate glue after placement of an endoprosthesis

    SciTech Connect

    Cekirge, Saruhan; Akhan, Okan; Ozmen, Mustafa; Saatci, Isil; Besim, Aytekin

    1997-05-15

    A new technique using cyanoacrylate glue is suggested for closing the transparenchymal tract following metallic endoprosthesis placement in a patient with malignant biliary obstruction complicated by ascites. With this technique, complications related to bile reflux through the transparenchymal tract would be avoided after transhepatic endoprosthesis placement in patients who have ascites. This technique would also be useful for avoiding bleeding following transhepatic portal venous puncture.

  3. Partial long-stem resection Austin-Moore hip endoprosthesis in the treatment of metastases to the proximal femur.

    PubMed

    Chrobok, Adam; Spindel, Jerzy; Mrozek, Tomasz; Miszczyk, Leszek; Koczy, Bogdan; Tomasik, Patryk; Matysiakiewicz, Jacek

    2005-12-30

    Background. The proximal femur is a frequent location of bone metastases, and pathological fractures in this area are common. A pathological fracture and/or pain associated with bone destruction are indications for surgery. Among many methods of surgical treatment, partial resection and subsequent arthroplasty appears to be the most efficient. The low cost of the implant and the relatively simple surgical technique incline us to apply long-stem (305mm) partial Austin-Moore hip prosthesis in these cases. Material and methods. Between June 2003 and February 2005 we operated 31 patients (10 men and 21 women) for pathological fracture or proximal femur metastasis. The average age of these patients was 63.8 years. The most common primary neoplasmatic focus among the women was breast cancer (17 cases, 80%), and among the men, clarocellular renal cancer (3 cases, 34%). Results. In most cases - 21 patients (67%) - we achieved excellent or good outcome according to the Merle d'Aubigne Functional Test, as well as reasonable pain relief. Endoprosthesis dislocation occurred in 2 cases and early postoperative death in 2 other cases. Conclusions. Surgical treatment is needed in cases of actual or impending pathological fracture of the proximal femur. Resection arthroplasty is the method of choice in bone metastases to proximal femur. This procedure is well tolerated by patients. The use of long-stem partial Austin-Moore hip prosthesis appears to be a good alternative to costly modular implants, while its long stem protects the femoral shaft against fractures in cases where additional metastatic lesions are found there.

  4. [Treatment of medial ventral hernias with the use of synthetic endoprosthesis].

    PubMed

    Pushkin, S Iu; Belokonev, V I

    2010-01-01

    350 patients with medial ventral hernias were operated on. 307 of them had various concurrent diseases; 177 required simultaneous surgery on that account. Endoprosthesis (synthetic mesh) was fixed using an "inlay-sub-lay" technique. Local complications were detected in 19.4% of patients, 5.4% developed common complications. 1.1% of patients had died. Long-term hernia recurrence was registered in 1.1%.

  5. Management of common bile duct stones with a biliary endoprosthesis. Report on 40 cases.

    PubMed

    Peters, R; Macmathuna, P; Lombard, M; Karani, J; Westaby, D

    1992-10-01

    Endoscopic placement of a biliary endoprosthesis has been proposed for the management of choledocholithiasis when stone extraction is difficult or considered hazardous. Over a two year period this approach was used in 40 such patients. There were 24 women and 16 men with a median age of 76 years. In seven patients with severe cholangitis no attempt was made to extract the stones. Twenty three (57.5%) patients underwent a sphincterotomy and four (10%) needle knife papillotomy. The endoprosthesis insertion was considered a temporary measure in 13 (32.5%) patients and definitive treatment in 27 (67.5%). Bile duct drainage was established in all patients. Early complications occurred in six patients (15%), but were without sequelae. Late complications developed in eight (20%) of the patients and included biliary colic (four), cholangitis (three), and cholecystitis (one). Two patients (one cholangitis and one cholecystitis) died as a consequence of the complication. Only patients without a sphincterotomy developed cholangitis. A total of eight patients (20%) underwent surgery (one as an emergency) and nine a repeat endoscopic retrograde cholangio pancreatography (two as an emergency) to clear the duct. The remaining 23 patients are asymptomatic at a median of 13 months (range five to 24 months). Biliary endoprosthesis insertion for choledocholithiasis is an important alternative means of establishing drainage in selected cases, and is probably the optimum method of management for the elderly and or debilitated patients with previous cholecystectomy. Caution must be exercised, however, in patients with an in situ gall bladder.

  6. "Pros and cons" of total hip arthroplasty with metaphyseal Proxima endoprosthesis.

    PubMed

    Wraźen, Waldemar; Golec, Edward B; Tomaszewski, Krzysztof A; Golec, Piotr; Jaworowski, Michał de Lubicz; Dudkiewicz, Zbigniew

    2015-01-01

    The authors present their own experience concerning total hip arthroplasty with the metaphyseal prosthesis Proxima. Proxima, a metaphyseal prosthesis, provides an innovative supplement to total hip arthroplasty. In this study, the authors present their own experience using Proxima in patients with hip osteoarthritis. This study was performed between 2008 to 2013 and comprised of 62 patients, of which 38 were male (61.3%) and 24 female (38.7%). All patients were operated on due to hip osteoarthritis using total hip arthroplasty with the metaphyseal prosthesis Proxima. The age of patients included into the study ranged from 23 years to 62 years with the mean age of 46 years. The authors paid close attention to the "pros and cons" of surgical techniques and assessed clinical and radiological results in both the short and long-term observation periods. The clinical evaluation was based on the Harris Hip Score and radiological assessment of fixation of the acetabular cup of the endoprosthesis was based on Pradhan's criteria. The endoprosthesis Proxima stem was positioned using the manufacturer's recommended method, evaluating the direction, scope and duration of the displacement in the marrow cavity of the proximal stump of the femur. According to the authors' analysis, the surgery gives good functional and radiological results both in the short- and long-term observation periods. The effectiveness depends on precise qualification for surgery, proper surgical techniques and specific anatomical conditions of the proximal femur stump. The most common reasons for primary and secondary dislocations of the metaphyseal endoprosthesis Proxima stem occur during the first three months post surgery. This is due to incorrect surgical techniques, which disregard the importance of specific anatomical conditions of the proximal femoral stump, which affects Proxima implantation, and cause deviations towards a varus or valgus orientation.

  7. EVAR using the Nellix Sac-anchoring endoprosthesis: treatment of favourable and adverse anatomy.

    PubMed

    Krievins, D K; Holden, A; Savlovskis, J; Calderas, C; Donayre, C E; Moll, F L; Katzen, B; Zarins, C K

    2011-07-01

    The study aimed to review the results of endovascular aneurysm repair (EVAR) using a novel sac-anchoring endoprosthesis in patients with favourable and adverse anatomy. This is a prospective, multicentre, clinical trial. The Nellix endoprosthesis consists of dual, balloon-expandable endoframes, surrounded by polymer-filled endobags, which obliterate the aneurysm sac and maintain endograft position. The study reviewed worldwide clinical experience and Core Lab evaluation of computed tomography (CT) scans. From 2008 to 2010, 34 patients (age 71 ± 8 years, abdominal aortic aneurysm (AAA) diameter 5.8 ± 0.8 cm) were treated at four clinical sites. Seventeen patients (50%) met the inclusion criteria for Food and Drug Administration (FDA)-approved endografts (favourable anatomy); 17 (50%) had one or more adverse anatomic feature: neck length <10 mm (24%), neck angle >60° (9%) and iliac diameter >23 mm (38%). Device deployment was successful in all patients; iliac aneurysm treatment preserved hypogastric patency. Perioperative mortality was 1/34 (2.9%); one patient died at 10 months of congestive heart failure (CHF); one patient had a secondary procedure at 15 months. During 15 ± 6 months follow-up, there were no differences in outcome between favourable and adverse anatomy patients. Follow-up CT extending up to 2 years revealed no change in aneurysm size or endograft position and no new endoleaks. Favourable and adverse anatomy patients can be successfully treated using the Nellix sac-anchoring endoprosthesis. Early results are promising but longer-term studies are needed. Copyright © 2011 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

  8. [Placing an endoprosthesis to maintain arterial canal permeability in lamb neonates].

    PubMed

    Godart, F; Jaillard, S; Corseaux, D; Houyel, L; Storme, L; Jude, B; Vincentelli, A; Rey, C

    2003-05-01

    Placing an endoprosthesis in the arterial canal in order to maintain permeability is a possible alternative to performing a modified Blalock-Taussig type surgical systemico-pulmonary anastomosis. This was studied in an animal model. Twelve newborn lambs, weighing from 1.8 to 3.5 kg, were catheterised in the neonatal period in order to place a stent. Three had a partial ligature of the pulmonary artery in utero. During the initial angiography, the canal was occluded in ten of them. Different types of coronary endoprosthesis were used: Multi link tetra TM and RX Herculink TM (Guidant Europe SA), Niroyal (Boston Scientific International), Bx Velocity (Cordis, Johnson and Johnson), Jostent (Jomed). The length of the endoprostheses varied from 12 to 18 mm and the diameter from 3.5 to 6 mm. Implantation was successful 10 out of 12 times: in one case, implantation was complicated by a fatal haemopericardium, and in another by pulmonary artery embolism. Nine animals out of 10 were followed up for 1 to 2 months. At autopsy verification, the canal was permeable in 7 cases with the development of a neointima and zones of moderate stenosis with intimal hyperplasia. In 2 animals the canal was occluded at the aortic level in a zone not covered by the endoprosthesis. Three animals died after implantation: the 2 implantation failures. A third animal with a well inserted prosthesis and a permeable canal died on day 1 from an unknown cause. Placing a stent in the arterial canal is a possible alternative to performing an aorto-pulmonary shunt. Coronary stents seem well adapted and this study does not allow any conclusions to be made at this time on the best type of stent. Further studies will be necessary in order to validate this concept before its use in congenital cardiopathies.

  9. Modular shield

    DOEpatents

    Snyder, Keith W.

    2002-01-01

    A modular system for containing projectiles has a sheet of material including at least a polycarbonate layer held by a metal frame having a straight frame member corresponding to each straight edge of the sheet. Each frame member has a U-shaped shield channel covering and holding a straight edge of the sheet and an adjacent U-shaped clamp channel rigidly held against the shield channel. A flexible gasket separates each sheet edge from its respective shield channel; and each frame member is fastened to each adjacent frame member only by clamps extending between adjacent clamp channels.

  10. Endoluminal Repair of a Dardik Prosthesis Pseudoaneurysm Using the Wallgraft Endoprosthesis

    SciTech Connect

    Zanchetta, Mario; Rigatelli, Gianluca; Konstantinos, Dimopoulos; Girardi, Diego; Caminiti, Antonio; Pedon, Luigi; Zennaro, Marco; Maiolino, Pietro

    2001-03-15

    A 58-year-old man with a history of severe invalidating claudicatio intermittens underwent femoropopliteal bypass with a human umbilical vein graft. Seven years later he presented with a painful enlarging mass in the middle portion of his right thigh. The duplex scan showed a pseudoaneurysm of the body of the prosthesis, which was confirmed by angiography. As an alternative to surgical management, Wallgraft endoprosthesis was used for endoluminal exclusion of the pseudoaneurysm. To our knowledge, this technique has never been used before in such a case.

  11. [Usefulness of urethral endoprosthesis in the management of urinary retention after brachytherapy for localized prostate cancer].

    PubMed

    Kerkeni, W; Chahwan, C; Lenormand, C; Dubray, B; Benyoucef, A; Pfister, C

    2014-03-01

    Brachytherapy is a possible treatment for localized low risk prostate cancer. Although this option is minimally invasive, some side effects may occur. Acute retention of urine (ARU) has been observed in 5% to 22% of cases and can be prevented in most cases by alpha-blocker treatment. Several alternatives have been reported in the literature for the management of ARU following brachytherapy: prolonged suprapubic catheterization, transurethral resection of the prostate and also intermittent self-catheterization. The authors report an original endoscopic approach, using urethral endoprosthesis, with a satisfactory voiding status.

  12. Modular Certification

    NASA Technical Reports Server (NTRS)

    Rushby, John; Miner, Paul S. (Technical Monitor)

    2002-01-01

    Airplanes are certified as a whole: there is no established basis for separately certifying some components, particularly software-intensive ones, independently of their specific application in a given airplane. The absence of separate certification inhibits the development of modular components that could be largely "precertified" and used in several different contexts within a single airplane, or across many different airplanes. In this report, we examine the issues in modular certification of software components and propose an approach based on assume-guarantee reasoning. We extend the method from verification to certification by considering behavior in the presence of failures. This exposes the need for partitioning, and separation of assumptions and guarantees into normal and abnormal cases. We then identify three classes of property that must be verified within this framework: safe function, true guarantees, and controlled failure. We identify a particular assume-guarantee proof rule (due to McMillan) that is appropriate to the applications considered, and formally verify its soundness in PVS.

  13. [New compounds for improving wear behavior of a tumor knee endoprosthesis].

    PubMed

    Lehner, S; Steinhauser, E; Mittelmeier, W; Stur, S; Gradinger, R

    2001-03-01

    Wear of the central bushing made of ultra-high molecular weight polyethylene (PE-UHMW) of the hinged knee endoprosthesis of a tumour-resection system is the leading reason for revision. The aim of the study was to optimize the wear characteristics of the endoprosthesis on the basis of the tribological properties of new materials and an additional finite element (FE) calculation taking account of the given design. In screening tests the reference combination of PE-UHMW bushing and CoCr axis--used in the clinical setting--was first tested. The PE-UHMW bushing was then replaced by one made of each of the materials reinforced high-density polyethylene (PE-HD) and carbon fibre-reinforced epoxy resin (CFRP). In addition, a new material combination with an alumina ceramic bushing and a CFRP axis was investigated. In comparison with the reference combination PE-UHMW/metal, the combination of ceramic bushing and CFRP axis showed less wear. However, with the particular design of the prosthesis studied here, high mechanical loading applied experimentally resulted in mechanical failure. FE calculations confirmed these experimental results. Improvement of the wear characteristics of this specific implant caused therefore be achieved only by optimizing the bearing design.

  14. Endovascular Treatment of Aneurysms of the Popliteal Artery By a Covered Endoprosthesis

    PubMed Central

    Wissgott, Christian; Lüdtke, Christopher W; Vieweg, Hendryk; Scheer, Fabian; Lichtenberg, Michael; Schlöricke, Erik; Andresen, Reimer

    2014-01-01

    PURPOSE The current gold standard of popliteal artery aneurysm (PAA) treatment is saphenous vein bypass grafting. The aim of this retrospective single-center study is to investigate the safety and efficacy in the treatment of PAA by an endovascular implanted covered endoprosthesis. MATERIALS AND METHODS Ten patients, mean age 64.6 (range, 52–78) years, with PAA were treated with an expanded Polytetrafluoroethylen (ePTFE)-covered stent graft (Viabahn®, W.L. Gore and Associates Inc, Flagstaff, AZ, USA). In median, 1.4 prostheses were implanted with a median length of 180 mm. Follow-up visits included determination of ankle-brachial index (ABI) and color-coded duplex sonography. RESULTS The technical success rate was 100% (10/10). Clinically, there was an increase in ABI from 0.62 ± 0.17 to 0.91 ± 0.15 postinterventionally and to 0.89 ± 0.16 after an average follow-up of 24.7 months. During the follow-up period, 2 (20%) stent occlusions occurred; both of them were treated with a bypass graft. CONCLUSION The treatment of PAA with covered endoprosthesis is a safe and effective alternative to open surgical therapy, where open surgical therapy is contraindicated or patient refused open surgery. PMID:25574145

  15. Partial distal deployment for precise placement of the GORE Thoracic Endoprosthesis.

    PubMed

    Stanley, Gregory A

    2017-08-01

    The GORE TAG Thoracic Endoprosthesis (TAG) device (W. L. Gore & Associates, Flagstaff, Ariz) and the GORE Conformable TAG Thoracic Endoprosthesis (CTAG) are commonly implanted and effective stent grafts for use during thoracic endovascular aortic repair. Precise placement of the endograft is paramount during thoracic endovascular aortic repair, but like all thoracic stent grafts, maldeployment with inaccurate landing has been reported. The partial distal deployment technique describes an alteration of the TAG and CTAG deployment mechanism to allow isolated deployment of the distal half of the graft, which provides stability during deployment. The graft can be safely repositioned after partial distal deployment, thus allowing precise positioning in the proximal landing zone. Similarly, this technique can be used for precision in the distal landing zone, making the TAG and CTAG devices the only thoracic endografts currently available in the United States with a distal-first deployment option. A discussion of the usefulness of this technique and potential pitfalls is included. Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

  16. [APPLICATION OF PREPARATION OF COCARNIT FOR PATIENTS AFTER ENDOPROSTHESIS OF HIP AND KNEE JOINTS].

    PubMed

    Korzh, N A; Filippenko, V A; Leont'eva, F S; Tulyakov, V A; Bondarenko, S E

    2015-01-01

    In the article the results of clinical researches of efficiency of preparation of Cocarnit are resulted for patients after endoprosthesis of large joints. It is routine that for patients, receiving preparation of Cocarnit after the operation period there was a decline in the amount of complaints of patients on the total somatical state. Preparation of Ccocarnit was positively estimated outside patients, meaningful by-reactions, serving reason of abolition of preparation, was not marked. At the reception preparation of Cocarnit greater part of investigational laboratory indexes (table of contents of glucose, β-lipoproteines, total chondroitisulfates, TBC-productes (malonic dyaldehyde), activity of aspartataminotransferase, alkaline phosphatase and β-glutamyltranspeptidase), the indexes of clinical blood test and leucocytar indexes during a supervision did not have reliable differences from such as the persons of the control group, that confirms good bearab leness of the indicated preparation. Application preparation of Cocarnit for patients in composition the chart of treatment of patients after endoprosthesis of large joints brought maintenance over of cholesterol to the decline, glycoproteins, TBC-products (malonic dyaldehyde), activity of alaninaminotransferase, that specifies on normalizing influence of the indicated preparation in relation to the basic types of exchange of matters.

  17. The Possibilities to Decrease the Coefficient of Friciton Between Head and Socket of the Endoprosthesis of Hip Joint

    NASA Astrophysics Data System (ADS)

    Haringová, Andrea; Stračár, Karol; Prikkel, Karol

    2014-12-01

    The article deals with the question of physical parameters that could positively influence the overall lifetime of hip joint endoprosthesis. As the important physical parameter it was selected the coefficient of friction. The contribution offers possibilities how to decrease the coefficient of friction and experimentally test these assumptions

  18. Modular robot

    DOEpatents

    Ferrante, Todd A.

    1997-01-01

    A modular robot may comprise a main body having a structure defined by a plurality of stackable modules. The stackable modules may comprise a manifold, a valve module, and a control module. The manifold may comprise a top surface and a bottom surface having a plurality of fluid passages contained therein, at least one of the plurality of fluid passages terminating in a valve port located on the bottom surface of the manifold. The valve module is removably connected to the manifold and selectively fluidically connects the plurality of fluid passages contained in the manifold to a supply of pressurized fluid and to a vent. The control module is removably connected to the valve module and actuates the valve module to selectively control a flow of pressurized fluid through different ones of the plurality of fluid passages in the manifold. The manifold, valve module, and control module are mounted together in a sandwich-like manner and comprise a main body. A plurality of leg assemblies are removably connected to the main body and are removably fluidically connected to the fluid passages in the manifold so that each of the leg assemblies can be selectively actuated by the flow of pressurized fluid in different ones of the plurality of fluid passages in the manifold.

  19. Modular robot

    DOEpatents

    Ferrante, T.A.

    1997-11-11

    A modular robot may comprise a main body having a structure defined by a plurality of stackable modules. The stackable modules may comprise a manifold, a valve module, and a control module. The manifold may comprise a top surface and a bottom surface having a plurality of fluid passages contained therein, at least one of the plurality of fluid passages terminating in a valve port located on the bottom surface of the manifold. The valve module is removably connected to the manifold and selectively fluidically connects the plurality of fluid passages contained in the manifold to a supply of pressurized fluid and to a vent. The control module is removably connected to the valve module and actuates the valve module to selectively control a flow of pressurized fluid through different ones of the plurality of fluid passages in the manifold. The manifold, valve module, and control module are mounted together in a sandwich-like manner and comprise a main body. A plurality of leg assemblies are removably connected to the main body and are removably fluidically connected to the fluid passages in the manifold so that each of the leg assemblies can be selectively actuated by the flow of pressurized fluid in different ones of the plurality of fluid passages in the manifold. 12 figs.

  20. Initial clinical experience with a sac-anchoring endoprosthesis for aortic aneurysm repair.

    PubMed

    Donayre, Carlos E; Zarins, Christopher K; Krievins, Dainis K; Holden, Andrew; Hill, Andrew; Calderas, Carlos; Velez, Jaime; White, Rodney A

    2011-03-01

    All current aortic endografts depend on proximal and distal fixation to prevent migration. However, migration and rupture can occur, particularly in patients with aortic necks that are short or angulated, or both. We present our initial clinical experience with a new sac-anchoring endoprosthesis designed to anchor and seal the device within the aneurysm sac. The initial worldwide experience using a new endoprosthesis for the treatment of aortic aneurysms (Nellix Endovascular, Palo Alto, Calif) was reviewed. The endoprosthesis consists of dual balloon-expandable endoframes surrounded by polymer-filled endobags designed to obliterate the aneurysm sac and maintain endograft position. Clinical results and follow-up contrast computed tomography (CT) scans at 30 days and 6 and 12 months were reviewed. The endograft was successfully deployed in 21 patients with infrarenal aortic aneurysms measuring 5.7 ± 0.7 cm (range, 4.3-7.4 cm). Two patients with common iliac aneurysms were treated with sac-anchoring extenders that maintained patency of the internal iliac artery. Infusion of 71 ± 37 mL of polymer (range, 19-158 mL) into the aortic endobags resulted in complete aneurysm exclusion in all patients. Mean implant time was 76 ± 35 minutes, with 33 ± 17 minutes of fluoroscopy time and 180 ± 81 mL of contrast; estimated blood loss was 174 ± 116 mL. One patient died during the postoperative period (30-day mortality, 4.8%), and one died at 10 months from non-device-related causes. During a mean follow-up of 8.7 ± 3.1 months and a median of 6.3 months, there were no late aneurysm- or device-related adverse events and no secondary procedures. CT imaging studies at 6 months and 1 year revealed no increase in aneurysm size, no device migration, and no new endoleaks. One patient had a limited proximal type I endoleak at 30 days that resolved at 60 days and remained sealed. One patient has an ongoing distal type I endoleak near the iliac bifurcation, with no change in aneurysm

  1. Aortic Endoprosthesis for the Treatment of Native Aortic Coarctation and Concomitant Aneurysm in an Octogenarian Patient.

    PubMed

    Rabellino, Martín; Kotowicz, Vadim; Kenny, Alberto; Kohan, Andres Alejandro; García-Mónaco, Ricardo

    2015-11-01

    We report a case of an 82-year-old female patient with native coarctation of the aorta and poststenotic aneurysm of the descending thoracic aorta. On consultation, she was receiving 4 antihypertensive drugs, and physical examination revealed nonpalpable lower-limb pulses with intermittent claudication at 50 min. Because of her age, high surgical risk and combination of lesions, endovascular treatment was suggested. Placement of a Valiant thoracic aorta endoprosthesis followed by coarctation angioplasty was performed. At 48 hr, the patient was discharged on 1 antihypertensive drug, palpable pulses on both limbs and a normal ankle-brachial index. At 1 month follow-up, the patient remained as discharged and multislice computed tomography angiography depicted complete coarctation expansion without residual stenosis, exclusion of the aortic aneurysm, and no signs of endoleaks.

  2. [Rehabilitation of patients after total endoprosthesis replacement of hip joint by the method of functional electrostimulation].

    PubMed

    Oskanian, T L; Solopova, I A; Grishin, A A; Sidorov, V D

    2008-01-01

    Patients after total endoprosthesis replacement of hip joint underwent method of functional electrostimulation (FES) with the purpose to recovery correct walking stereotype, to increase leisured muscle strength, to prevent secondary coxarthrosis development via stimulation or relaxation of muscles, and for analgesia of joints and pain zones at walking. Results of treatment of 143 patients received rehabilitation course of FES (15 procedures of 30 minutes) were compared with results of treatment of 54 patients received traditional methods. It is shown that FES is effective method of rehabilitation because it makes possible to improve muscle strength significantly, to eliminate or reduce motor deficit, to decrease pain syndrome, to form correct walking stereotype, and to perform early prophylaxis of secondary coxarthrosis on contralateral side. The main advantage of proposed method of nonmedicamental influence is better clinic-biomechanical result without use of drugs.

  3. CEMENTLESS ENDOPROSTHESIS IN THE TREATMENT OF GIANT CELL TUMOR OF THE TIBIA: EIGHTEEN YEARS OF EVOLUTION

    PubMed Central

    Mello, Glauco Pauka; Sonehara, Helio Ayabe; Neto, Mario Armani

    2015-01-01

    This is a case report on a giant cell tumor of the juxta-articular proximal tibia with a pathological fracture. A female patient presented pain and increased local volume after falling from her own height. She underwent clinical examination, radiographic examination and puncture biopsy. A diagnosis of giant cell tumor was made. The patient was then treated with tumor resection and use of an unconventional partial endoprosthesis of the tibia with preservation of the joint surface of the tibial plateau. The patient evolved with improvement of symptoms and maintenance of joint function of the operated limb, absence of recurrence and complications, without any need for reoperation over 18 years of follow-up. PMID:27026973

  4. Titanium 2013

    USGS Publications Warehouse

    2014-01-01

    Titanium is the ninth most abundant element in the earth's crust and can be found in nearly all rocks and sediments. It is a lithophile element with a strong affinity for oxygen and is not found as a pure metal in nature. Titanium was first isolated as a pure metal in 1910, but it was not until 1948 that the metal was produced commercially using the Kroll process (named after its developer, William Kroll) to reduce titanium tetrachloride with magnesium to produce titanium metal.

  5. [Experience with using polymer-metal endoprosthesis in the treatment of medial fractures of the femur neck in elderly patients].

    PubMed

    Dudko, G E

    1990-02-01

    The author analyses his experience in using polymer metalic endoprostheses in 36 patients with medial fractures and false joints of the femoral neck in the elderly persons. The average age of the patients operated was 74 years. The head and the neck of the endoprosthesis were made of polymer: polyamide-12 and its limb was made of metal: titan BT-5. The immediate and the long-term results (6 months to 10 years) have been studied. The functional results of endoprosthetics were good in 27 cases (81.8%), satisfactory in 4 cases (12.2%) and bad in 2 cases (6%). Using polymer (polyamide-12) as a construction material for endoprostheses contributes to a softer transmission of the efforts and stresses from the articular cartilage to the subchondral and remote parts of the skeleton and improves the restoration of the biomechanical equilibrium between the endoprosthesis and the bone structure.

  6. Modular Fixturing System

    NASA Technical Reports Server (NTRS)

    Littell, Justin Anderson (Inventor); Street, Jon P. (Inventor)

    2017-01-01

    The modular fixturing system of the present invention is modular, reusable and capable of significant customization, both in terms of system radius and system height, allowing it to be arranged and rearranged in numerous unique configurations. The system includes multiple modular stanchions having stanchion shafts and stanchion feet that removably attach to apertures in a table. Angle brackets attached to the modular stanchions support shelves. These shelves in turn provide support to work pieces during fabrication processes such as welding.

  7. Portable modular detection system

    DOEpatents

    Brennan, James S.; Singh, Anup; Throckmorton, Daniel J.; Stamps, James F.

    2009-10-13

    Disclosed herein are portable and modular detection devices and systems for detecting electromagnetic radiation, such as fluorescence, from an analyte which comprises at least one optical element removably attached to at least one alignment rail. Also disclosed are modular detection devices and systems having an integrated lock-in amplifier and spatial filter and assay methods using the portable and modular detection devices.

  8. Process for synthesizing titanium carbide, titanium nitride and titanium carbonitride

    DOEpatents

    Koc, R.; Glatzmaier, G.C.

    1995-05-23

    A process is disclosed for synthesizing titanium carbide, titanium nitride or titanium carbonitride. The process comprises placing particles of titanium, a titanium salt or titanium dioxide within a vessel and providing a carbon-containing atmosphere within the vessel. The vessel is heated to a pyrolysis temperature sufficient to pyrolyze the carbon to thereby coat the particles with a carbon coating. Thereafter, the carbon-coated particles are heated in an inert atmosphere to produce titanium carbide, or in a nitrogen atmosphere to produce titanium nitride or titanium carbonitride, with the heating being of a temperature and time sufficient to produce a substantially complete solid solution.

  9. Process for synthesizing titanium carbide, titanium nitride and titanium carbonitride

    DOEpatents

    Koc, Rasit; Glatzmaier, Gregory C.

    1995-01-01

    A process for synthesizing titanium carbide, titanium nitride or titanium carbonitride. The process comprises placing particles of titanium, a titanium salt or titanium dioxide within a vessel and providing a carbon-containing atmosphere within the vessel. The vessel is heated to a pyrolysis temperature sufficient to pyrolyze the carbon to thereby coat the particles with a carbon coating. Thereafter, the carbon-coated particles are heated in an inert atmosphere to produce titanium carbide, or in a nitrogen atmosphere to produce titanium nitride or titanium carbonitride, with the heating being of a temperature and time sufficient to produce a substantially complete solid solution.

  10. Outcomes of Limb-Sparing Surgery Using Two Generations of Metal Endoprosthesis in 45 Dogs With Distal Radial Osteosarcoma. A Veterinary Society of Surgical Oncology Retrospective Study.

    PubMed

    Mitchell, Katherine E; Boston, Sarah E; Kung, Marvin; Dry, Sarah; Straw, Rod C; Ehrhart, Nicole P; Ryan, Stewart D

    2016-01-01

    To report outcomes in dogs with distal radial osteosarcoma (OSA) treated with metal endoprosthesis limb-sparing surgery and compare outcomes between 2 generations of endoprosthesis. Multi-institutional retrospective case series. Forty-five dogs with distal radial OSA treated with endoprosthesis and chemotherapy. Data of dogs treated with either first-generation endoprosthesis (GEN1) or second-generation endoprosthesis (GEN2) were sourced from medical records and radiographs. Surgical outcomes included postoperative lameness assessment and the presence, severity, and time to onset of complications. Oncologic outcomes included presence of local recurrence or metastasis, time to onset of local recurrence, metastasis-free interval (MFI), and survival time. Results for surgical and oncologic outcomes were compared between GEN1 and GEN2. Twenty-eight dogs received GEN1 and 17 dogs received GEN2. There were 39 complications (96%, 14 minor, 29 major) including infection (78%), implant-related complication (36%), and local recurrence (24%). Metastatic frequency was 67% and median MFI was 188 days (95% confidence interval [CI]: 126-250 days). Survival time ranged from 34 days to 6.1 years with a median of 289 days (95% CI: 207-371 days). There was no significant difference in complication severity, frequency, time to complication, MFI, or survival time between dogs receiving GEN1 and GEN2. There was no significant difference in outcomes between dogs receiving GEN1 and GEN2 for limb-sparing surgery of the radius. Metastatic frequency and survival time for metal endoprosthesis were similar to that of amputation with curative intent chemotherapy. © Copyright 2015 by The American College of Veterinary Surgeons.

  11. First-in-Human Experience With the Gore Balloon-Expandable Covered Endoprosthesis in Iliac Artery Occlusive Disease.

    PubMed

    Holden, Andrew; Merrilees, Stephen; Buckley, Brendan; Connor, Brigid; Colgan, Frances; Hill, Andrew

    2017-02-01

    To report the first-in-human iliac artery experience of a new balloon-expandable covered endoprosthesis. A prospective, single-center pilot study recruited 30 symptomatic patients (mean age 64 years; 18 men) to evaluate the safety and early efficacy of the new Gore balloon-expandable covered endoprosthesis for the treatment of de novo or restenotic common and/or external iliac artery lesions. According to protocol, up to 2 discrete lesions could be treated with a maximum total treated length ≤110 mm. Follow-up included clinical evaluation with duplex ultrasound at 1, 6, and 12 months. Data are presented through 12-month follow-up. The primary safety endpoint was a composite of device- or procedure-related death, myocardial infarction, or amputation in the treated leg within 30 days of the index procedure. Multiple performance outcomes were also evaluated. The primary 30-day safety endpoint was 0%. Per-subject estimates of primary patency, freedom from target lesion revascularization, and freedom from target vessel revascularization were 100% at 1 and 6 months and 96.6% at 12 months. Estimates of assisted primary and secondary patency were both 100% at 12 months. Freedom from major adverse events at 12 months was 100%. Most patients experienced improvements in Rutherford category, ankle-brachial index, and functional status that were sustained to 12 months. This positive first-in-human experience with the Gore balloon-expandable covered endoprosthesis suggests this device will have an important role in the management of aortoiliac occlusive disease.

  12. Implementing Modular A Levels.

    ERIC Educational Resources Information Center

    Holding, Gordon

    This document, which is designed for curriculum managers at British further education (FE) colleges, presents basic information on the implementation and perceived benefits of the General Certificate of Education (GCE) modular A (Advanced) levels. The information was synthesized from a survey of 12 FE colleges that introduced the modular A levels…

  13. Modular tokamak configuration

    SciTech Connect

    Thomson, S.L.

    1985-01-01

    This report is concerned with the modular tokamak configuration, and presents information on the following topics: modularity; external vacuum boundary; vertical maintenance; combined reactor building/biological shield with totally remote maintenance; independent TF coils; minimum TF coil bore; saddle PF coils; and heat transport system in bore.

  14. Modular Buildings Buying Guide.

    ERIC Educational Resources Information Center

    Morris, Susan

    1991-01-01

    Suggests that child care program directors who are expanding their programs or opening new child care centers investigate the possibility of renting, leasing, or purchasing a modular building. Discusses the advantages of modular buildings over conventional building construction or rented space in an occupied building. Provides information about…

  15. Vertebral Augmentation with Nitinol Endoprosthesis: Clinical Experience in 40 Patients with 1-Year Follow-up

    SciTech Connect

    Anselmetti, Giovanni Carlo; Manca, Antonio; Marcia, Stefano; Chiara, Gabriele; Marini, Stefano; Baroud, Gamal; Regge, Daniele; Montemurro, Filippo

    2013-05-08

    PurposeThis study was designed to assess the clinical outcomes of patients treated by vertebral augmentation with nitinol endoprosthesis (VNE) to treat painful vertebral compression fractures.MethodsForty patients with one or more painful osteoporotic VCF, confirmed by MRI and accompanied by back-pain unresponsive to a minimum 2 months of conservative medical treatment, underwent VNE at 42 levels. Preoperative and postoperative pain measured with Visual Analog Scale (VAS), disability measured by Oswestry Disability Index (ODI), and vertebral height restoration (measured with 2-dimensional reconstruction CT) were compared at last follow-up (average follow-up 15 months). Cement extravasation, subsequent fractures, and implant migration were recorded.ResultsLong-term follow-up was obtained in 38 of 40 patients. Both VAS and ODI significantly improved from a median of 8.0 (range 5–10) and 66 % (range 44–88 %) to 0.5 (range 0–8) and 6 % (range 6–66 %), respectively, at 1 year (p < 0.0001). Vertebral height measurements comparing time points increased in a statistically significant manner (ANOVA, p < 0.001). Overall cement extravasation rate was 9.5 %. Discal and venous leakage rates were 7.1 and 0 % respectively. No symptomatic extravasations occurred. Five of 38 (13.1 %) patients experienced new spontaneous, osteoporotic fractures. No device change or migration was observed.ConclusionsVNE is a safe and effective procedure that is able to provide long-lasting pain relief and durable vertebral height gain with a low rate of new fractures and cement leakages.

  16. Long-Term Outcome of the GORE EXCLUDER AAA Endoprosthesis for Treatment of Infrarenal Aortic Aneurysms.

    PubMed

    Poublon, Claire G; Holewijn, Suzanne; van Sterkenburg, Steven M M; Tielliu, Ignace F J; Zeebregts, Clark J; Reijnen, Michel M P J

    2017-05-01

    To evaluate long-term outcome of GORE EXCLUDER AAA Endoprosthesis (W.L. Gore & Associates, Inc, Flagstaff, Arizona) for elective treatment of infrarenal aortic aneurysms and to evaluate performance of different generations of the device. A retrospective analysis was performed of 248 patients undergoing elective endovascular aneurysm repair with the GORE EXCLUDER between January 2000 and December 2015 in 2 hospitals. Primary endpoint was reintervention-free survival. Secondary endpoints were technical success, overall survival, rupture-free survival, endoleaks, sac diameter change (> 5 mm), limb occlusion, and migration (> 5 mm). Median follow-up time was 26 months (range, 1-190 months). Assisted primary technical success was 96.8%. Reintervention-free survival for 5 and 10 years was 85.2% and 75.6%, respectively. Independent risk factors for reintervention were technical success (P < .001), type I endoleak (P < .001), and type II endoleak (P = .003). Late adverse events requiring reintervention included rupture (0.4%), limb occlusion (0.4%), and stent migration (0.4%). Type Ia (4.8%), Ib (2.8%), II (35.9%), and V (6.5%) endoleaks were reported throughout follow-up. Sac growth was more prevalent with the original GORE EXCLUDER compared with the low permeability GORE EXCLUDER (P = .001) and in the presence of type I, II, and V endoleaks (P < .05). Three conversions (1.2%) were performed. Overall survival at 5 and 10 years was 68.4% and 49.0%, with no reported aneurysm-related deaths. Treatment with the GORE EXCLUDER is effective with acceptable reintervention rates in the long-term and few device-related adverse events or ruptures up to 10 years. Observed late adverse events and new-onset endoleaks emphasize the need for long-term surveillance. Copyright © 2017 SIR. Published by Elsevier Inc. All rights reserved.

  17. Experience with the GORE EXCLUDER iliac branch endoprosthesis for common iliac artery aneurysms.

    PubMed

    van Sterkenburg, Steven M M; Heyligers, Jan M M; van Bladel, Mathijs; Verhagen, Hence J; Eefting, Daniël; van Sambeek, Marc R; Zeebregts, Clark J; Reijnen, Michel M P J

    2016-06-01

    In this study, we analyzed the procedural success and early outcome of endovascular treatment of a multicenter cohort of patients with common iliac artery (CIA) aneurysms treated with the new GORE EXCLUDER (W. L. Gore & Associates, Flagstaff, Ariz) iliac branch endoprosthesis (IBE). A retrospective cohort analysis was performed in 13 sites in The Netherlands. Anatomic, demographic, procedural, and follow-up data were assessed from hospital records. From November 2013 to December 2014, 51 CIA aneurysms were treated with an IBE in 46 patients. The median diameter of the treated aneurysm was 40.5 (range, 25.0-90.0) mm. The mean procedural time was 198 ± 56 minutes. All but one implantation were successful; two type Ib endoleaks were noticed, resulting in a procedural success rate of 93.5%. The two type Ib endoleaks spontaneously disappeared at 30 days. There was no 30-day mortality. Ipsilateral buttock claudication was present in only two cases at 30 days and disappeared during follow-up. The incidence of reported erectile dysfunction was low and severe ischemic complications were absent. After a mean follow-up of 6 months, data on 17 treated aneurysms were available. Two showed a stable diameter, whereas 15 showed a mean decrease of 3.9 ± 2.2 mm (P < .001). Reinterventions were performed in two patients (7.1%). The 6-month primary patency of the internal component of the IBE device was 94%. The use of the GORE EXCLUDER IBE device for CIA aneurysms is related to high procedural success, high patency rates, and low reintervention rates at short-term follow-up. Prospective data with longer follow-up are awaited to establish the role of the device in the treatment algorithm of CIA aneurysms. Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

  18. Treatment of malignant biliary obstruction by endoscopic implantation of iridium 192 using a new double lumen endoprosthesis

    SciTech Connect

    Siegel, J.H.; Lichtenstein, J.L.; Pullano, W.E.; Ramsey, W.H.; Rosenbaum, A.; Halpern, G.; Nonkin, R.; Jacob, H.

    1988-07-01

    Iridium 192 seeds contained in a ribbon were preloaded into a new double lumen 11 Fr endoprosthesis which was then inserted into malignant strictures of the bile duct and ampulla and left in place for 48 hours until 5000 rads were delivered to the tumor. The procedure was carried out in 14 patients (7 women, 7 men; mean age, 63.2 years; range, 46 to 86 years). Six patients were treated for cholangiocarcinomas, four with pancreatic carcinomas, and four with ampullary carcinomas. No complications occurred. The mean survival of the group was 7 months (range, 3 days to 27 months). This new technique provides both intraluminal brachytherapy and biliary drainage and is inserted intraduodenally across the papilla of Vater avoiding puncture of the liver and external hardware required by the percutaneous technique and hardware necessitated with a nasobiliary tube. Following removal of the iridium prosthesis, a large caliber endoprosthesis is inserted for continued decompression. Because of proven efficacy of endoprostheses, this new technique should be considered when intraluminal irradiation is indicated.

  19. Titanium Cranioplasty

    PubMed Central

    Gordon, D. S.; Blair, G. A. S.

    1974-01-01

    The technique of repairing defects of the skull with titanium is described. The skull contour can be accurately reproduced. The technique is simpler than wiring or suturing methods. The material is inert, radiolucent, and rigid. ImagesFIG. 1FIG. 2FIG. 3FIG. 5FIG. 6FIG. 7 PMID:4834099

  20. Modular kinetic analysis.

    PubMed

    Krab, Klaas

    2011-01-01

    Modularization is an important strategy to tackle the study of complex biological systems. Modular kinetic analysis (MKA) is a quantitative method to extract kinetic information from such a modularized system that can be used to determine the control and regulatory structure of the system, and to pinpoint and quantify the interaction of effectors with the system. The principles of the method are described, and the relation with metabolic control analysis is discussed. Examples of application of MKA are given. Copyright © 2011 Elsevier Inc. All rights reserved.

  1. Modular tokamak magnetic system

    DOEpatents

    Yang, Tien-Fang

    1988-01-01

    A modular tokamak system comprised of a plurality of interlocking moldules. Each module is comprised of a vacuum vessel section, a toroidal field coil, moldular saddle coils which generate a poloidal magnetic field and ohmic heating coils.

  2. Successful modular cosmology

    NASA Astrophysics Data System (ADS)

    Kadota, Kenji; Stewart, Ewan D.

    2003-07-01

    We present a modular cosmology scenario where the difficulties encountered in conventional modular cosmology are solved in a self-consistent manner, with definite predictions to be tested by observation. Notably, the difficulty of the dilaton finding its way to a precarious weak coupling minimum is made irrelevant by having eternal modular inflation at the vacuum supersymmetry breaking scale after the dilaton is stabilised. Neither this eternal inflation nor the subsequent non-slow-roll modular inflation destabilise the dilaton from its precarious minimum due to the low energy scale of the inflation and consequent small back reaction on the dilaton potential. The observed flat CMB spectrum is obtained from fluctuations in the angular component of a modulus near a symmetric point, which are hugely magnified by the roll down of the modulus to Planckian values, allowing them to dominate the final curvature perturbation. We also give precise calculations of the spectral index and its running.

  3. A Modular Robotic Architecture

    DTIC Science & Technology

    1990-11-01

    DATES COVERED AD-A232 007 Januar 1991 professional paper5 FUNOING NUMBERS A MODULAR ROBOTIC ARCHITECTURE PR: ZE92 WU: DN300029 PE: 0602936N - S. AUTHOR...mobile robots will help alleviate these problems, and, if made widely available, will promote standardization and compatibility among systems throughout...the industry. The Modular Robotic Architecture (MRA) is a generic control system that meets the above needs by providing developers with a standard set

  4. Squeaking friction phenomena in ceramic hip endoprosthesis: Modeling and experimental validation

    NASA Astrophysics Data System (ADS)

    Ouenzerfi, G.; Massi, F.; Renault, E.; Berthier, Y.

    2015-06-01

    minimizing friction rising factors (such edge loading and situations promoting metal transfer or stripe wear) or by developing endoprosthesis design to avoid the unstable vibrations, regressing the squeaking emission to a negligible phenomenon.

  5. Modularity and mental architecture.

    PubMed

    Robbins, Philip

    2013-11-01

    Debates about the modularity of cognitive architecture have been ongoing for at least the past three decades, since the publication of Fodor's landmark book The Modularity of Mind. According to Fodor, modularity is essentially tied to informational encapsulation, and as such is only found in the relatively low-level cognitive systems responsible for perception and language. According to Fodor's critics in the evolutionary psychology camp, modularity simply reflects the fine-grained functional specialization dictated by natural selection, and it characterizes virtually all aspects of cognitive architecture, including high-level systems for judgment, decision making, and reasoning. Though both of these perspectives on modularity have garnered support, the current state of evidence and argument suggests that a broader skepticism about modularity may be warranted. WIREs Cogn Sci 2013, 4:641-649. doi: 10.1002/wcs.1255 CONFLICT OF INTEREST: The author has declared no conflicts of interest for this article. For further resources related to this article, please visit the WIREs website.

  6. Preparation of titanium diboride powder

    DOEpatents

    Brynestad, Jorulf; Bamberger, Carlos E.

    1985-01-01

    Finely-divided titanium diboride or zirconium diboride powders are formed by reacting gaseous boron trichloride with a material selected from the group consisting of titanium powder, zirconium powder, titanium dichloride powder, titanium trichloride powder, and gaseous titanium trichloride.

  7. Metal Bonded Titanium Diboride

    DTIC Science & Technology

    1952-03-01

    of specimens made from titanium diboride plus 10 percent titanium and 30 percent zirconium . X 100. 22 6. Microstructures of specimens made from...chromium. X 1000 26 10. Microstructures of specimens made from titanium diboride plus 10 percent titanium and 30 percent zirconium . X 1200 27 11. Gain in...shock resistance and oxidation resistance of titanium diboride but zirconium diboride which is isomorphous with titanium diboride has been reported6

  8. Improvement of Liver Function, Quality of Life and Survival after Insertion of Endoprosthesis in Advance Malignant Biliary Obstruction.

    PubMed

    Ullah, A A; Rahman, A; Chowdhury, L H; Bhuiya, A H

    2017-01-01

    Obstructive jaundice due to advance malignancy is a fatal problem. It most commonly occurs at the distal common bile duct or at the hilum of liver. Magnetic Resonance Cholangio Pancreatography (MRCP) and Computed Tomography (CT) are most useful in identifying the underlying cause as well as localize the position of the stricture. For those patients with unresectable disease, progressive jaundice constitutes an immediate threat to their survival, in addition to significant loss to their quality of life secondary to pruritus, malaise and cholangitis. Effective and lasting decompression of the biliary tree is a priority and consists of positioning of a biliary endoprosthesis (stent). To observe the improvement of liver function, quality of life and survival after successful insertion of endoprosthesis (stenting) in malignant biliary obstruction, a study was performed in the department of surgery, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh from September 2013 to August 2014, in 50 patients with clinically visible jaundice and unresectable disease. There were significant (p<0.001) reductions in the levels of serum bilirubin, serum alkaline phosphatase, serum SGPT and Prothrombin time from the time of admission to 2 weeks and 3 weeks after stenting. Physical and functional quality of life was greatly improved 2-4 weeks after stenting, where emotional quality remained the same throughout the study period. Successful palliation by stenting of malignant biliary obstruction is a priority to achieve improvements in liver function, quality of life and prolong survival. Endoscopic stent placement appears to be safe, well tolerated and can be offered without delay as a primary treatment option for all patients with unresectable malignant biliary lesion.

  9. Symmetric modular torsatron

    DOEpatents

    Rome, J.A.; Harris, J.H.

    1984-01-01

    A fusion reactor device is provided in which the magnetic fields for plasma confinement in a toroidal configuration is produced by a plurality of symmetrical modular coils arranged to form a symmetric modular torsatron referred to as a symmotron. Each of the identical modular coils is helically deformed and comprise one field period of the torsatron. Helical segments of each coil are connected by means of toroidally directed windbacks which may also provide part of the vertical field required for positioning the plasma. The stray fields of the windback segments may be compensated by toroidal coils. A variety of magnetic confinement flux surface configurations may be produced by proper modulation of the winding pitch of the helical segments of the coils, as in a conventional torsatron, winding the helix on a noncircular cross section and varying the poloidal and radial location of the windbacks and the compensating toroidal ring coils.

  10. Self Evolving Modular Network

    NASA Astrophysics Data System (ADS)

    Tokunaga, Kazuhiro; Kawabata, Nobuyuki; Furukawa, Tetsuo

    We propose a novel modular network called the Self-Evolving Modular Network (SEEM). The SEEM has a modular network architecture with a graph structure and these following advantages: (1) new modules are added incrementally to allow the network to adapt in a self-organizing manner, and (2) graph's paths are formed based on the relationships between the models represented by modules. The SEEM is expected to be applicable to evolving functions of an autonomous robot in a self-organizing manner through interaction with the robot's environment and categorizing large-scale information. This paper presents the architecture and an algorithm for the SEEM. Moreover, performance characteristic and effectiveness of the network are shown by simulations using cubic functions and a set of 3D-objects.

  11. Modular optical detector system

    DOEpatents

    Horn, Brent A.; Renzi, Ronald F.

    2006-02-14

    A modular optical detector system. The detector system is designed to detect the presence of molecules or molecular species by inducing fluorescence with exciting radiation and detecting the emitted fluorescence. Because the system is capable of accurately detecting and measuring picomolar concentrations it is ideally suited for use with microchemical analysis systems generally and capillary chromatographic systems in particular. By employing a modular design, the detector system provides both the ability to replace various elements of the detector system without requiring extensive realignment or recalibration of the components as well as minimal user interaction with the system. In addition, the modular concept provides for the use and addition of a wide variety of components, including optical elements (lenses and filters), light sources, and detection means, to fit particular needs.

  12. Fracture of the cobalt-chromium modular femoral neck component in total hip arthroplasty.

    PubMed

    Mencière, M-L; Amouyel, T; Taviaux, J; Bayle, M; Laterza, C; Mertl, P

    2014-09-01

    Total hip prostheses using cervico-metaphyseal modularity were designed to better replicate the geometry of the native extra-medullary femur. However, they are associated with numerous complications including corrosion, disassembly, pseudotumours and, most notably, fractures of the modular neck. All reported cases of modular neck fractures occurred with titanium components (Ti-6Al-4V). To prevent this weakness, manufacturers developed modular necks made of cobalt-chromium (Co-Cr). We report a fracture of a long, 8° varus, Co-Cr modular neck connected to a 36-mm short (-3.5mm) femoral head. The fracture occurred 22 months post-implantation in a woman who had a low level of physical activity and a body mass index of 28.7 kg/m(2). To our knowledge, this case is the first reported instance of Co-Cr modular neck fracture. It may challenge the wisdom of further developing this modularity design, as our patient had none of the known risk factors for modular neck fracture. In addition, cases of pseudotumour have been reported with Co-Cr modular necks subjected to fretting corrosion, which contributed to the fracture in our patient. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  13. Modular biowaste monitoring system

    NASA Technical Reports Server (NTRS)

    Fogal, G. L.

    1975-01-01

    The objective of the Modular Biowaste Monitoring System Program was to generate and evaluate hardware for supporting shuttle life science experimental and diagnostic programs. An initial conceptual design effort established requirements and defined an overall modular system for the collection, measurement, sampling and storage of urine and feces biowastes. This conceptual design effort was followed by the design, fabrication and performance evaluation of a flight prototype model urine collection, volume measurement and sampling capability. No operational or performance deficiencies were uncovered as a result of the performance evaluation tests.

  14. Modular Optofluidic Systems (MOPS)

    NASA Astrophysics Data System (ADS)

    Ackermann, Tobias N.; Dietvorst, Jiri; Sanchis, Ana; Salvador, Juan P.; Munoz-Berbel, Xavier; Alvarez-Conde, Erica; Kopp, Daniel; Zappe, Hans; Marco, M.-Pilar; Llobera, Andreu

    2016-12-01

    Elementary PDMS-based building blocks of fluidic, optical and optofluidic components for Lab on a chip (LOC) platforms has here been developed. All individual modules are compatible and can be anchored and released with the help of puzzle-type connectors This approach is a powerful toolbox to create modular optofluidic systems (MOPS), which can be modified/upgraded to user needs and in-situ reconfigurable. In addition, the PDMS can locally be functionalized, defining a modular biosensor. Measurements in absorbance and fluorescence have been pursued as demonstrator.

  15. Modular total absorption spectrometer

    NASA Astrophysics Data System (ADS)

    Karny, M.; Rykaczewski, K. P.; Fijałkowska, A.; Rasco, B. C.; Wolińska-Cichocka, M.; Grzywacz, R. K.; Goetz, K. C.; Miller, D.; Zganjar, E. F.

    2016-11-01

    The design and performance of the Modular Total Absorption Spectrometer built and commissioned at the Oak Ridge National Laboratory is presented. The active volume of the detector is approximately one ton of NaI(Tl), which results in very high full γ energy peak efficiency of 71% at 6 MeV and nearly flat efficiency of around 81.5% for low energy γ-rays between 300 keV and 1 MeV. In addition to the high peak efficiency, the modular construction of the detector permits the use of a γ-coincidence technique in data analysis as well as β-delayed neutron observation.

  16. Titanium "irons" and titanium "steels"

    NASA Astrophysics Data System (ADS)

    Firstov, S. A.; Tkachenko, S. V.; Kuz'menko, N. N.

    2009-01-01

    Special features of the structure and properties of promising structural alloys based on the Ti-Si system are described. The similarity of the diagrams of phase equilibria of the Fe-Si and Fe-C systems makes it possible to classify the alloys of the Ti-Si system into titanium "steels" and "irons" depending on the silicon content. Results of studies of the effects of alloying, heat treatment, and thermomechanical treatment on the phase and structural transformations and on some properties of alloys based on the Ti-Si system are presented.

  17. Hydriding of Titanium.

    DTIC Science & Technology

    1998-03-01

    hole. The metals used to make these couples with titanium included HY80 steel , 316 stainless steel , five-nines aluminum, 6061 aluminum, and zinc. All...the other surfaces. Titanium Coupled With Other Metals The corrosion potentials of grade 2 titanium galvanically coupled with naval brass, HY80 steel ...2 titanium; naval brass caused titanium to become an anode. At room temperature, HY80 steel and 316 stainless steel couples exhibited corrosion

  18. Modular invariant inflation

    SciTech Connect

    Kobayashi, Tatsuo; Nitta, Daisuke; Urakawa, Yuko

    2016-08-08

    Modular invariance is a striking symmetry in string theory, which may keep stringy corrections under control. In this paper, we investigate a phenomenological consequence of the modular invariance, assuming that this symmetry is preserved as well as in a four dimensional (4D) low energy effective field theory. As a concrete setup, we consider a modulus field T whose contribution in the 4D effective field theory remains invariant under the modular transformation and study inflation drived by T. The modular invariance restricts a possible form of the scalar potenntial. As a result, large field models of inflation are hardly realized. Meanwhile, a small field model of inflation can be still accomodated in this restricted setup. The scalar potential traced during the slow-roll inflation mimics the hilltop potential V{sub ht}, but it also has a non-negligible deviation from V{sub ht}. Detecting the primordial gravitational waves predicted in this model is rather challenging. Yet, we argue that it may be still possible to falsify this model by combining the information in the reheating process which can be determined self-completely in this setup.

  19. Modular invariant gaugino condensation

    SciTech Connect

    Gaillard, M.K.

    1991-05-09

    The construction of effective supergravity lagrangians for gaugino condensation is reviewed and recent results are presented that are consistent with modular invariance and yield a positive definite potential of the noscale type. Possible implications for phenomenology are briefly discussed. 29 refs.

  20. Modular invariant inflation

    NASA Astrophysics Data System (ADS)

    Kobayashi, Tatsuo; Nitta, Daisuke; Urakawa, Yuko

    2016-08-01

    Modular invariance is a striking symmetry in string theory, which may keep stringy corrections under control. In this paper, we investigate a phenomenological consequence of the modular invariance, assuming that this symmetry is preserved as well as in a four dimensional (4D) low energy effective field theory. As a concrete setup, we consider a modulus field T whose contribution in the 4D effective field theory remains invariant under the modular transformation and study inflation drived by T. The modular invariance restricts a possible form of the scalar potenntial. As a result, large field models of inflation are hardly realized. Meanwhile, a small field model of inflation can be still accomodated in this restricted setup. The scalar potential traced during the slow-roll inflation mimics the hilltop potential Vht, but it also has a non-negligible deviation from Vht. Detecting the primordial gravitational waves predicted in this model is rather challenging. Yet, we argue that it may be still possible to falsify this model by combining the information in the reheating process which can be determined self-completely in this setup.

  1. A Modular CAI System.

    ERIC Educational Resources Information Center

    Van Der Mast, Charles

    The experimental CAI system which is being tested at Delft University of Technology is structured in a modular manner to account for high changeability. The concept formulated for this project was the outcome of research into technological, organizational, and educational developments in CAI, and the enumeration of the common aspects of the…

  2. Modular core holder

    SciTech Connect

    Mueller, J.; Cole, C.W.; Hamid, S.; Lucas, J.K.

    1991-03-05

    This patent describes a modular core holder. It comprises: a sleeve, forming an internal cavity for receiving a core. The sleeve including segments; support means, overlying the sleeve, for supporting the sleeve; and access means, positioned between at least two of the segments of the sleeve, for allowing measurement of conditions within the internal cavity.

  3. MRV - Modular Robotic Vehicle

    NASA Technical Reports Server (NTRS)

    Ridley, Justin; Bluethmann, Bill

    2015-01-01

    The Modular Robotic Vehicle, or MRV, completed in 2013, was developed at the Johnson Space Center in order to advance technologies which have applications for future vehicles both in space and on Earth. With seating for two people, MRV is a fully electric vehicle modeled as a "city car", suited for busy urban environments.

  4. Modular Perspectives on Bilingualism.

    ERIC Educational Resources Information Center

    Francis, Norbert

    2002-01-01

    This research review traces the current discussion on models of bilingualism to the contributions of Vygotsky and Luria. Proposes that a modular approach to studying the different aspects of bilingual development promises to chart a course toward finding a broader common ground around research findings and interpretations that appear to be…

  5. Modularity in robotic systems

    NASA Technical Reports Server (NTRS)

    Tesar, Delbert; Butler, Michael S.

    1989-01-01

    Most robotic systems today are designed one at a time, at a high cost of time and money. This wasteful approach has been necessary because the industry has not established a foundation for the continued evolution of intelligent machines. The next generation of robots will have to be generic, versatile machines capable of absorbing new technology rapidly and economically. This approach is demonstrated in the success of the personal computer, which can be upgraded or expanded with new software and hardware at virtually every level. Modularity is perceived as a major opportunity to reduce the 6 to 7 year design cycle time now required for new robotic manipulators, greatly increasing the breadth and speed of diffusion of robotic systems in manufacturing. Modularity and its crucial role in the next generation of intelligent machines are the focus of interest. The main advantages that modularity provides are examined; types of modules needed to create a generic robot are discussed. Structural modules designed by the robotics group at the University of Texas at Austin are examined to demonstrate the advantages of modular design.

  6. Modular, Multilayer Perceptron

    NASA Technical Reports Server (NTRS)

    Cheng, Li-Jen; Liu, Tsuen-Hsi

    1991-01-01

    Combination of proposed modular, multilayer perceptron and algorithm for its operation recognizes new objects after relatively brief retraining sessions. (Perceptron is multilayer, feedforward artificial neural network fully connected and trained via back-propagation learning algorithm.) Knowledge pertaining to each object to be recognized resides in subnetwork of full network, therefore not necessary to retrain full network to recognize each new object.

  7. [The quality management in clinical diagnostic laboratory in conditions of the Federal Center of traumatology, orthopedics and endoprosthesis replacement of Minzdrav of Russia (Cheboksary)].

    PubMed

    Nikolaev, N S; Nazarova, V V; Dobrovol'skaia, N Iu; Orlova, A V; Pchelova, N N

    2014-10-01

    The article presents experience of clinical diagnostic laboratory of the Federal Center of traumatology, orthopedics and endoprosthesis replacement of Minzdrav of Russia (Cheboksary) in the area of quality management of medical laboratory services on the basis of evaluation of efficacy and effectiveness of processes. The factors effecting quality of functioning of clinical diagnostic laboratory are indicated. The criteria and indicators of efficacy of work of employees of clinical diagnostic laboratory are presented.

  8. Results covering 20 years use of the cement-free Zweymüller Alloclassic total endoprosthesis of the hip joint.

    PubMed

    Weissinger, M; Helmreich, C; Pöll, G

    2010-06-01

    From an initial group of 206 hips in 190 patients we carried out a retrospective clinical and radiological control of 74 hips in 72 patients covering a period of 20 years. Indications in 74 operated hips evidenced 48x(64.9%) primary and 26x(35.1%) secondary coxarthrosis. The average age at the time of operation was 53 years (37 years-68 years). All 72 patients with 74 hips received cement-free self- cutting Alloclassic screw cups of pure Titanium together with a cement-free square Alloclassic stem consisting of Titan- Aluminium-Niob alloy according to Zweymüller. Regarding the technique of operation we used the approach after Watson-Jones in the supine position. As prophylaxis against thrombosis 40% of the patients received derivates of heparine and 60% had anticoagulant therapy with cumarine. Prophylaxis against heterotopic ossifications were not carried out at this juncture in our department. After an average post-operational examination lapse of 20 years we were able to examine 72 patients (37.9%) with 74 hips (35.9%) clinically and radiologically. Further classification of the 72 patients records 47 females and 25 males. The average age at the time of operation was 53 years and at the time of post-operational check-up to 74 years. For the clinical post-operational check-up (n=74) we used the Harris Hip Score. Further evaluation shows 12x(16.2%) excellent results, 26x(35.1%) good and 29x(39.2%) fair results. In 7 patients (9.5%) we had to observe poor results because of multimorbidity, although also in these cases stability of TEP had been achieved. The radiological post-operational check-up of the 74 stable hips (35.9%) shows an average excentric position of the head of 1.4 mm (0 mm up until 4 mm) compared with 1 mm after 10 years. Over an average of about 20 years we carried out an exchange of the inlay and the head because of excentric position of the head, which correlates to a rate of reoperation of 6.8%. In 2000 and 2001 we published our 10 year results

  9. Modular reflector concept study

    NASA Astrophysics Data System (ADS)

    Vaughan, D. H.

    1981-02-01

    The feasibility was studied of constructing large space structures, specifically a 100 meter paraboloidal R.F. reflector, by individually deploying a number of relatively small structural modules, and then joining them to form a single large structure in orbit. The advantage of this approach is that feasibility of a large antenna may be demonstrated by ground and flight tests of several smaller and less costly subelements. Thus, initial development costs are substantially reduced and a high degree of reliability can be obtained without commitment to construction of a very large system. The three candidate structural concepts investigated are: (1) the deployable cell module; (2) the paraboloidal extendable truss antenna adapted to modular assembly; and (3) the modular extendable truss antenna (META).

  10. Modular space station

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The modular space station comprising small, shuttle-launched modules, and characterized by low initial cost and incremental manning, is described. The initial space station is designed to be delivered into orbit by three space shuttles and assembled in space. The three sections are the power/subsystems module, the crew/operations module, and the general purpose laboratory module. It provides for a crew of six. Subsequently duplicate/crew/operations and power/subsystems modules will be mated to the original modules, and provide for an additional six crewmen. A total of 17 research and applications modules is planned, three of which will be free-flying modules. Details are given on the program plan, modular characteristics, logistics, experiment support capability and requirements, operations analysis, design support analyses, and shuttle interfaces.

  11. ATIS - A modular approach

    NASA Astrophysics Data System (ADS)

    Kirson, Allan

    The author describes a modular approach to the design of an in-vehicle navigation and route guidance system that supports a phased implementation of the technology, and anticipates expected differences in implementation in different parts of the world and for different makes and models of vehicle. A series of sensors in the vehicle are used to determine the vehicle's position by dead reckoning and map-matching. The system then calculates the best route to the selected destination, taking into account the real-time traffic information received from a traffic management center, and presents route guidance instructions to the user as the route is traversed. Attention is given to modularity considerations, vehicle positioning, driver support, vehicle-to-infrastructure communications, and the role of standards.

  12. Modular reflector concept study

    NASA Technical Reports Server (NTRS)

    Vaughan, D. H.

    1981-01-01

    The feasibility was studied of constructing large space structures, specifically a 100 meter paraboloidal R.F. reflector, by individually deploying a number of relatively small structural modules, and then joining them to form a single large structure in orbit. The advantage of this approach is that feasibility of a large antenna may be demonstrated by ground and flight tests of several smaller and less costly subelements. Thus, initial development costs are substantially reduced and a high degree of reliability can be obtained without commitment to construction of a very large system. The three candidate structural concepts investigated are: (1) the deployable cell module; (2) the paraboloidal extendable truss antenna adapted to modular assembly; and (3) the modular extendable truss antenna (META).

  13. Quantum spaces are modular

    NASA Astrophysics Data System (ADS)

    Freidel, Laurent; Leigh, Robert G.; Minic, Djordje

    2016-11-01

    At present, our notion of space is a classical concept. Taking the point of view that quantum theory is more fundamental than classical physics, and that space should be given a purely quantum definition, we revisit the notion of Euclidean space from the point of view of quantum mechanics. Since space appears in physics in the form of labels on relativistic fields or Schrödinger wave functionals, we propose to define Euclidean quantum space as a choice of polarization for the Heisenberg algebra of quantum theory. We show, following Mackey, that generically, such polarizations contain a fundamental length scale and that contrary to what is implied by the Schrödinger polarization, they possess topologically distinct spectra. These are the modular spaces. We show that they naturally come equipped with additional geometrical structures usually encountered in the context of string theory or generalized geometry. Moreover, we show how modular space reconciles the presence of a fundamental scale with translation and rotation invariance. We also discuss how the usual classical notion of space comes out as a form of thermodynamical limit of modular space while the Schrödinger space is a singular limit.

  14. [Modular enteral nutrition in pediatrics].

    PubMed

    Murillo Sanchís, S; Prenafeta Ferré, M T; Sempere Luque, M D

    1991-01-01

    Modular Enteral Nutrition may be a substitute for Parenteral Nutrition in children with different pathologies. Study of 4 children with different pathologies selected from a group of 40 admitted to the Maternal-Childrens Hospital "Valle de Hebrón" in Barcelona, who received modular enteral nutrition. They were monitored on a daily basis by the Dietician Service. Modular enteral nutrition consists of modules of proteins, peptides, lipids, glucids and mineral salts-vitamins. 1.--Craneo-encephalic traumatisms with loss of consciousness, Feeding with a combination of parenteral nutrition and modular enteral nutrition for 7 days. In view of the tolerance and good results of the modular enteral nutrition, the parenteral nutrition was suspended and modular enteral nutrition alone used up to a total of 43 days. 2.--55% burns with 36 days of hyperproteic modular enteral nutrition together with normal feeding. A more rapid recovery was achieved with an increase in total proteins and albumin. 3.--Persistent diarrhoea with 31 days of modular enteral nutrition, 5 days on parenteral nutrition alone and 8 days on combined parenteral nutrition and modular enteral nutrition. In view of the tolerance and good results of the modular enteral nutrition, the parenteral nutrition was suspended. 4.--Mucoviscidosis with a total of 19 days on modular enteral nutrition, 12 of which were exclusively on modular enteral nutrition and 7 as a night supplement to normal feeding. We administered proteic intakes of up to 20% of the total calorific intake and in concentrations of up to 1.2 calories/ml of the final preparation, always with a good tolerance. Modular enteral nutrition can and should be used as a substitute for parenteral nutrition in children with different pathologies, thus preventing the complications inherent in parenteral nutrition.

  15. Titanium hermetic seals

    DOEpatents

    Brow, Richard K.; Watkins, Randall D.

    1995-07-04

    Titanium is prenitrided by being heated in a nitrogen environment under conditions which give rise to the formation of a titanium-nitride surface layer on the titanium. Titanium thus prenitrided may be used in electrical components which are hermetically sealed using silicate glasses and standard glass sealing techniques. According to the method of the invention, alkali volatilization and formation of deleterious interfacial silicide are inhibited.

  16. Titanium hermetic seals

    DOEpatents

    Brow, Richard K.; Watkins, Randall D.

    1995-01-01

    Titanium is prenitrided by being heated in a nitrogen environment under conditions which give rise to the formation of a titanium-nitride surface layer on the titanium. Titanium thus prenitrided may be used in electrical components which are hermetically sealed using silicate glasses and standard glass sealing techniques. According to the method of the invention, alkali volatilization and formation of deleterious interfacial silicide are inhibited.

  17. LMDS Lightweight Modular Display System.

    DTIC Science & Technology

    1982-02-16

    LIGHTWEIGHT MODULAR DISPLAY SYSTEM %C AD Gomez SW Wolfe EW Davenport BD Calder 16 February 1982 * / DTrSJUL 22 3829 Approved for public release...375 4. TITLE (and Subtitle) S. TYPE OF REPORT & PERIOD COVERED Oct 77 to Jan 82 LMDS LIGHTWEIGHT MODULAR DISPLAY SYSTEM S. PERFORMING ORG. REPORT...Processing Power Distribution Modular Display Low Cost Tactical Display Tactical Tablet Lightweight Display General Purpose Dispiay Functional Modules Touch

  18. Influence of Different Patellofemoral Design Variations Based on Genesis II Total Knee Endoprosthesis on Patellofemoral Pressure and Kinematics

    PubMed Central

    Lange, Barbara; Herzog, Yvonne; Schnauffer, Peter; Leichtle, Carmen I.; Wülker, Nikolaus

    2017-01-01

    In total knee arthroplasty (TKA), patellofemoral groove design varies greatly and likely has a distinct influence on patellofemoral biomechanics. To analyse the selective influence, five patellofemoral design variations were developed based on Genesis II total knee endoprosthesis (original design, being completely flat, being laterally elevated, being medially elevated, and both sides elevated) and made from polyamide using rapid prototyping. Muscle-loaded knee flexion was simulated on 10 human knee specimens using a custom-made knee simulator, measuring the patellofemoral pressure distribution and tibiofemoral and patellofemoral kinematics. The measurements were carried out in the native knee as well as after TKA with the 5 design prototypes. The overall influence of the different designs on the patellofemoral kinematics was small, but we found detectable effects for mediolateral tilt (p < 0.05 for 35°–80° flexion) and translation of the patella (p < 0.045 for 20°–65° and 75°–90°), especially for the completely flat design. Considering patellofemoral pressures, major interindividual differences were seen between the designs, which, on average, largely cancelled each other out. These results suggest that the elevation of the lateral margin of the patellofemoral groove is essential for providing mediolateral guidance, but smooth contouring as with original Genesis II design seems to be sufficient. The pronounced interindividual differences identify a need for more patellofemoral design options in TKA. PMID:28255225

  19. Influence of Different Patellofemoral Design Variations Based on Genesis II Total Knee Endoprosthesis on Patellofemoral Pressure and Kinematics.

    PubMed

    Leichtle, Ulf G; Lange, Barbara; Herzog, Yvonne; Schnauffer, Peter; Leichtle, Carmen I; Wülker, Nikolaus; Lorenz, Andrea

    2017-01-01

    In total knee arthroplasty (TKA), patellofemoral groove design varies greatly and likely has a distinct influence on patellofemoral biomechanics. To analyse the selective influence, five patellofemoral design variations were developed based on Genesis II total knee endoprosthesis (original design, being completely flat, being laterally elevated, being medially elevated, and both sides elevated) and made from polyamide using rapid prototyping. Muscle-loaded knee flexion was simulated on 10 human knee specimens using a custom-made knee simulator, measuring the patellofemoral pressure distribution and tibiofemoral and patellofemoral kinematics. The measurements were carried out in the native knee as well as after TKA with the 5 design prototypes. The overall influence of the different designs on the patellofemoral kinematics was small, but we found detectable effects for mediolateral tilt (p < 0.05 for 35°-80° flexion) and translation of the patella (p < 0.045 for 20°-65° and 75°-90°), especially for the completely flat design. Considering patellofemoral pressures, major interindividual differences were seen between the designs, which, on average, largely cancelled each other out. These results suggest that the elevation of the lateral margin of the patellofemoral groove is essential for providing mediolateral guidance, but smooth contouring as with original Genesis II design seems to be sufficient. The pronounced interindividual differences identify a need for more patellofemoral design options in TKA.

  20. Sealing glasses for titanium and titanium alloys

    DOEpatents

    Brow, R.K.; Watkins, R.D.

    1988-01-21

    Glass compositions containing CaO, Al/sub 2/O/sub 3/, B/sub 2/O/sub 3/, SrO and BaO of various combinations of mole % are provided. These compositions are capable of forming stable glass-to-metal seals with titanium and titanium alloys, for use in components such as seals for battery headers.

  1. Sealing glasses for titanium and titanium alloys

    DOEpatents

    Brow, Richard K.; Watkins, Randall D.

    1992-01-01

    Glass compositions containing CaO, Al.sub.2 O.sub.3, B.sub.2 O.sub.3, SrO and BaO of various combinations of mole % are provided. These compositions are capable of forming stable glass-to-metal seals with titanium and titanium alloys, for use in components such as seals for battery headers.

  2. Cytotoxicity of titanium and titanium alloying elements.

    PubMed

    Li, Y; Wong, C; Xiong, J; Hodgson, P; Wen, C

    2010-05-01

    It is commonly accepted that titanium and the titanium alloying elements of tantalum, niobium, zirconium, molybdenum, tin, and silicon are biocompatible. However, our research in the development of new titanium alloys for biomedical applications indicated that some titanium alloys containing molybdenum, niobium, and silicon produced by powder metallurgy show a certain degree of cytotoxicity. We hypothesized that the cytotoxicity is linked to the ion release from the metals. To prove this hypothesis, we assessed the cytotoxicity of titanium and titanium alloying elements in both forms of powder and bulk, using osteoblast-like SaOS(2) cells. Results indicated that the metal powders of titanium, niobium, molybdenum, and silicon are cytotoxic, and the bulk metals of silicon and molybdenum also showed cytotoxicity. Meanwhile, we established that the safe ion concentrations (below which the ion concentration is non-toxic) are 8.5, 15.5, 172.0, and 37,000.0 microg/L for molybdenum, titanium, niobium, and silicon, respectively.

  3. The proximal modular neck in THA: a bridge too far: affirms.

    PubMed

    Dunbar, Michael J

    2010-09-07

    Modular necks are a relatively new innovation in total hip arthroplasty (THA), with several companies now offering modular neck options. The proposed advantages of reduced impingement, reduced dislocation rate, and better reconstitution of leg length and offset are compelling. However, few reports in the literature address the outcomes of these devices, and those that are published at best demonstrate equivalence to conventional THA. There are numerous disadvantages to this new technology. Neck dissociation has been reported with a specific design of the modular taper. Numerous case reports exist of the fracture of titanium modular femoral necks, with 1 large series of 5000 cases reporting a fracture rate of 1.4%. Fractures occurred more frequently in heavy men (>100 kg), with the preponderance of fractures occurring around the 2-year mark. Retrieval analysis demonstrates failure of the titanium components at the Morse taper junction of the neck and femoral stem at the point of maximal tension, likely related to notch sensitivity. The additional interface of modular necks in the effective joint space has the potential to generate significant metal ions through a pitting corrosion process. Evidence exists of highly elevated serum cobalt and chromium ions in a modular junction used in large-head THA supporting these concerns. The use of particular neck geometries, such as long retroverted necks, may adversely affect the local biomechanical forces on the femoral component. The proposed mechanism is an increased lever arm leading to increased torque on stair climbing or rising from a chair. Finally, modular necks add significant costs to the implant and the health care system. On balance, based on the literature, the proximal modular neck in THA is a bridge too far.

  4. Robotic hand with modular extensions

    DOEpatents

    Salisbury, Curt Michael; Quigley, Morgan

    2015-01-20

    A robotic device is described herein. The robotic device includes a frame that comprises a plurality of receiving regions that are configured to receive a respective plurality of modular robotic extensions. The modular robotic extensions are removably attachable to the frame at the respective receiving regions by way of respective mechanical fuses. Each mechanical fuse is configured to trip when a respective modular robotic extension experiences a predefined load condition, such that the respective modular robotic extension detaches from the frame when the load condition is met.

  5. Modular analysis of biological networks.

    PubMed

    Kaltenbach, Hans-Michael; Stelling, Jörg

    2012-01-01

    The analysis of complex biological networks has traditionally relied on decomposition into smaller, semi-autonomous units such as individual signaling pathways. With the increased scope of systems biology (models), rational approaches to modularization have become an important topic. With increasing acceptance of de facto modularity in biology, widely different definitions of what constitutes a module have sparked controversies. Here, we therefore review prominent classes of modular approaches based on formal network representations. Despite some promising research directions, several important theoretical challenges remain open on the way to formal, function-centered modular decompositions for dynamic biological networks.

  6. Titanium sponge on titanium substrate for titanium electrolytic capacitor anodes

    NASA Astrophysics Data System (ADS)

    Ki, Jun-Wan

    2005-07-01

    Capacitors are energy storage devices capable of supplying electric energy. Volumetric and gravimetric energy storage efficiencies are some of the important criteria for evaluating electrolytic capacitors as energy storage devices. High energy density capacitors can be achieved by anodic growth of a dielectric film on surface enhanced valve-metal. Electrodes with high surface area accessible along with wide and short conduction paths (electrolyte) have advantages as power devices. Surface-enhanced metal substrates can be made by various methods. One method is by oxidation followed by reduction. Oxidation of a metal and reduction of oxide are generally associated with volume changes. During growth of an oxide scale on a metal substrate, the volume expansion of an attached oxide scale can only occur in the thickness direction. During subsequent reduction of the oxide volume shrinkage occurs. It can take place along all directions, in particular in the plane of the oxide scale. This shrinkage leads to pores in the metal layer that is formed by the reduction of the oxide scale. Therefore, a layer of titanium sponge can be obtained by the oxidation plus reduction method. The titanium sponge layer can be anodized in order to grow a thin dielectric film on the surface of the sponge metal. In this way it is made into a capacitor anode. Reduction of titanium oxide scale with magnesium or calcium produces titanium sponge with different morphologies. Magnesium-reduced sponge has a higher degree of porosity than calcium-reduced sponge. The different morphologies of the reduced oxide scale result from different reduction behaviors in the presence of magnesium or calcium. Possible mechanisms are suggested to explain how magnesium and calcium affect the reduction behavior of titanium oxide. Because titanium anodic films tend to have high leakage current, titanium is not used for commercial electrolytic capacitor anodes. Nitrogen and oxygen doping of titanium surface layer enables

  7. Modular biometric system

    NASA Astrophysics Data System (ADS)

    Hsu, Charles; Viazanko, Michael; O'Looney, Jimmy; Szu, Harold

    2009-04-01

    Modularity Biometric System (MBS) is an approach to support AiTR of the cooperated and/or non-cooperated standoff biometric in an area persistent surveillance. Advanced active and passive EOIR and RF sensor suite is not considered here. Neither will we consider the ROC, PD vs. FAR, versus the standoff POT in this paper. Our goal is to catch the "most wanted (MW)" two dozens, separately furthermore ad hoc woman MW class from man MW class, given their archrivals sparse front face data basis, by means of various new instantaneous input called probing faces. We present an advanced algorithm: mini-Max classifier, a sparse sample realization of Cramer-Rao Fisher bound of the Maximum Likelihood classifier that minimize the dispersions among the same woman classes and maximize the separation among different man-woman classes, based on the simple feature space of MIT Petland eigen-faces. The original aspect consists of a modular structured design approach at the system-level with multi-level architectures, multiple computing paradigms, and adaptable/evolvable techniques to allow for achieving a scalable structure in terms of biometric algorithms, identification quality, sensors, database complexity, database integration, and component heterogenity. MBS consist of a number of biometric technologies including fingerprints, vein maps, voice and face recognitions with innovative DSP algorithm, and their hardware implementations such as using Field Programmable Gate arrays (FPGAs). Biometric technologies and the composed modularity biometric system are significant for governmental agencies, enterprises, banks and all other organizations to protect people or control access to critical resources.

  8. Modular Biometric Monitoring System

    NASA Technical Reports Server (NTRS)

    Chmiel, Alan J. (Inventor); Humphreys, Bradley T. (Inventor)

    2017-01-01

    A modular system for acquiring biometric data includes a plurality of data acquisition modules configured to sample biometric data from at least one respective input channel at a data acquisition rate. A representation of the sampled biometric data is stored in memory of each of the plurality of data acquisition modules. A central control system is in communication with each of the plurality of data acquisition modules through a bus. The central control system is configured to control communication of data, via the bus, with each of the plurality of data acquisition modules.

  9. Geometric Kac Moody modularity

    NASA Astrophysics Data System (ADS)

    Lynker, Monika; Schimmrigk, Rolf

    2006-05-01

    It is shown how the arithmetic structure of algebraic curves encoded in the Hasse-Weil L-function can be related to affine Kac-Moody algebras. This result is useful in relating the arithmetic geometry of Calabi-Yau varieties to the underlying exactly solvable theory. In the case of the genus three Fermat curve we identify the Hasse-Weil L-function with the Mellin transform of the twist of a number theoretic modular form derived from the string function of a non-twisted affine Lie algebra. The twist character is associated to the number field of quantum dimensions of the conformal field theory.

  10. Modular space station facilities.

    NASA Technical Reports Server (NTRS)

    Parker, P. J.

    1973-01-01

    The modular space station will operate as a general purpose laboratory (GPL). In addition, the space station will be able to support many attached or free-flying research and application modules that would be dedicated to specific projects like astronomy or earth observations. The GPL primary functions have been organized into functional laboratories including an electrical/electronics laboratory, a mechanical sciences laboratory, an experiment and test isolation laboratory, a hard data process facility, a data evaluation facility, an optical sciences laboratory, a biomedical and biosciences laboratory, and an experiment/secondary command and control center.

  11. Modular gear bearings

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (Inventor)

    2009-01-01

    A gearing system using modular gear bearing components. Each component is composed of a core, one or more modules attached to the core and two or more fastening modules rigidly attaching the modules to the core. The modules, which are attached to the core, may consist of gears, rollers or gear bearing components. The core orientation affects the orientation of the modules attached to the core. This is achieved via the keying arrangement of the core and the component modules that attach to the core. Such an arrangement will also facilitate the phase tuning of gear modules with respect to the core and other gear modules attached to the core.

  12. Modularity of music processing.

    PubMed

    Peretz, Isabelle; Coltheart, Max

    2003-07-01

    The music faculty is not a monolithic entity that a person either has or does not. Rather, it comprises a set of neurally isolable processing components, each having the potential to be specialized for music. Here we propose a functional architecture for music processing that captures the typical properties of modular organization. The model rests essentially on the analysis of music-related deficits in neurologically impaired individuals, but provides useful guidelines for exploring the music faculty in normal people, using methods such as neuroimaging.

  13. Modular and Hierarchically Modular Organization of Brain Networks

    PubMed Central

    Meunier, David; Lambiotte, Renaud; Bullmore, Edward T.

    2010-01-01

    Brain networks are increasingly understood as one of a large class of information processing systems that share important organizational principles in common, including the property of a modular community structure. A module is topologically defined as a subset of highly inter-connected nodes which are relatively sparsely connected to nodes in other modules. In brain networks, topological modules are often made up of anatomically neighboring and/or functionally related cortical regions, and inter-modular connections tend to be relatively long distance. Moreover, brain networks and many other complex systems demonstrate the property of hierarchical modularity, or modularity on several topological scales: within each module there will be a set of sub-modules, and within each sub-module a set of sub-sub-modules, etc. There are several general advantages to modular and hierarchically modular network organization, including greater robustness, adaptivity, and evolvability of network function. In this context, we review some of the mathematical concepts available for quantitative analysis of (hierarchical) modularity in brain networks and we summarize some of the recent work investigating modularity of structural and functional brain networks derived from analysis of human neuroimaging data. PMID:21151783

  14. Modular antenna design study

    NASA Technical Reports Server (NTRS)

    Ribble, J. W.

    1981-01-01

    The mechanical design of a modular antenna concept was developed sufficiently to allow manufacture of a working demonstration model of a module, to predict mass properties, and to make performance estimates for antenna reflectors composed of these modules. The primary features of this concept are: (1) each module is an autonomous structural element which can be attached to adjacent modules through a three point connection; (2) the upper surface is a folding hexagonal truss plate mechanism which serves as the supporting structure for a reflective surface; and (3) the entire truss and surface can be folded into a cylindrical envelope in which all truss elements are essentially parallel. The kinematic studies and engineering demonstration model fully verified the deployment kinematics, stowing philosophy, and deployment sequencing for large antenna modules. It was established that such modules can be stowed in packages as small as 25 cm in diameter, using 1.27 cm diameter structural tubes. The development activity indicates that this deployable modular approach towards building large structures in space will support erection of 450 m apertures for operation up to 3 GHz with a single space shuttle flight.

  15. Modular reflector concept study

    NASA Technical Reports Server (NTRS)

    Vaughan, D. H.

    1981-01-01

    A study was conducted to evaluate the feasibility of space erecting a 100 meter paraboloidal radio frequency reflector by joining a number of individually deployed structural modules. Three module design concepts were considered: (1) the deployable cell module (DCM); (2) the modular paraboloidal erectable truss antenna (Mod-PETA); and (3) the modular erectable truss antenna (META). With the space shuttle (STS) as the launch system, the methodology of packaging and stowing in the orbiter, and of dispensing, deploying and joining, in orbit, were studied and the necessary support equipment identified. The structural performance of the completed reflectors was evaluated and their overall operational capability and feasibility were evaluated and compared. The potential of the three concepts to maintain stable shape in the space environment was determined. Their ability to operate at radio frequencies of 1 GHz and higher was assessed assuming the reflector surface to consist of a number of flat, hexagonal facets. A parametric study was performed to determine figure degradation as a function of reflector size, flat facet size, and f/D ratio.

  16. Modular radiochemistry synthesis system

    SciTech Connect

    Satyamurthy, Nagichettiar; Barrio, Jorge R.; Amarasekera, Bernard; Van Dam, R. Michael; Olma, Sebastian; Williams, Dirk; Eddings, Mark; Shen, Clifton Kwang-Fu

    2015-12-15

    A modular chemical production system includes multiple modules for performing a chemical reaction, particularly of radiochemical compounds, from a remote location. One embodiment comprises a reaction vessel including a moveable heat source with the position thereof relative to the reaction vessel being controllable from a remote position. Alternatively the heat source may be fixed in location and the reaction vial is moveable into and out of the heat source. The reaction vessel has one or more sealing plugs, the positioning of which in relationship to the reaction vessel is controllable from a remote position. Also the one or more reaction vessel sealing plugs can include one or more conduits there through for delivery of reactants, gases at atmospheric or an elevated pressure, inert gases, drawing a vacuum and removal of reaction end products to and from the reaction vial, the reaction vial with sealing plug in position being operable at elevated pressures. The modular chemical production system is assembled from modules which can each include operating condition sensors and controllers configured for monitoring and controlling the individual modules and the assembled system from a remote position. Other modules include, but are not limited to a Reagent Storage and Delivery Module, a Cartridge Purification Module, a Microwave Reaction Module, an External QC/Analysis/Purification Interface Module, an Aliquotting Module, an F-18 Drying Module, a Concentration Module, a Radiation Counting Module, and a Capillary Reactor Module.

  17. Modular radiochemistry synthesis system

    DOEpatents

    Satyamurthy, Nagichettiar; Barrio, Jorge R; Amarasekera, Bernard; Van Dam, R. Michael; Olma, Sebastian; Williams, Dirk; Eddings, Mark A; Shen, Clifton Kwang-Fu

    2015-02-10

    A modular chemical production system includes multiple modules for performing a chemical reaction, particularly of radiochemical compounds, from a remote location. One embodiment comprises a reaction vessel including a moveable heat source with the position thereof relative to the reaction vessel being controllable from a remote position. Alternatively the heat source may be fixed in location and the reaction vial is moveable into and out of the heat source. The reaction vessel has one or more sealing plugs, the positioning of which in relationship to the reaction vessel is controllable from a remote position. Also the one or more reaction vessel sealing plugs can include one or more conduits there through for delivery of reactants, gases at atmospheric or an elevated pressure, inert gases, drawing a vacuum and removal of reaction end products to and from the reaction vial, the reaction vial with sealing plug in position being operable at elevated pressures. The modular chemical production system is assembled from modules which can each include operating condition sensors and controllers configured for monitoring and controlling the individual modules and the assembled system from a remote position. Other modules include, but are not limited to a Reagent Storage and Delivery Module, a Cartridge Purification Module, a Microwave Reaction Module, an External QC/Analysis/Purification Interface Module, an Aliquotting Module, an F-18 Drying Module, a Concentration Module, a Radiation Counting Module, and a Capillary Reactor Module.

  18. Preheating after modular inflation

    NASA Astrophysics Data System (ADS)

    Barnaby, Neil; Bond, J. Richard; Huang, Zhiqi; Kofman, Lev

    2009-12-01

    We study (p)reheating in modular (closed string) inflationary scenarios, with a special emphasis on Kähler moduli/Roulette models. It is usually assumed that reheating in such models occurs through perturbative decays. However, we find that there are very strong non-perturbative preheating decay channels related to the particular shape of the inflaton potential (which is highly nonlinear and has a very steep minimum). Preheating after modular inflation, proceeding through a combination of tachyonic instability and broad-band parametric resonance, is perhaps the most violent example of preheating after inflation known in the literature. Further, we consider the subsequent transfer of energy to the standard model sector in scenarios where the standard model particles are confined to a D7-brane wrapping the inflationary blow-up cycle of the compactification manifold or, more interestingly, a non-inflationary blow-up cycle. We explicitly identify the decay channels of the inflaton in these two scenarios. We also consider the case where the inflationary cycle shrinks to the string scale at the end of inflation; here a field theoretical treatment of reheating is insufficient and one must turn instead to a stringy description. We estimate the decay rate of the inflaton and the reheat temperature for various scenarios.

  19. Modular Robotic Vehicle

    NASA Technical Reports Server (NTRS)

    Borroni-Bird, Christopher E. (Inventor); Vitale, Robert L. (Inventor); Lee, Chunhao J. (Inventor); Ambrose, Robert O. (Inventor); Bluethmann, William J. (Inventor); Junkin, Lucien Q. (Inventor); Lutz, Jonathan J. (Inventor); Guo, Raymond (Inventor); Lapp, Anthony Joseph (Inventor); Ridley, Justin S. (Inventor)

    2015-01-01

    A modular robotic vehicle includes a chassis, driver input devices, an energy storage system (ESS), a power electronics module (PEM), modular electronic assemblies (eModules) connected to the ESS via the PEM, one or more master controllers, and various embedded controllers. Each eModule includes a drive wheel containing a propulsion-braking module, and a housing containing propulsion and braking control assemblies with respective embedded propulsion and brake controllers, and a mounting bracket covering a steering control assembly with embedded steering controllers. The master controller, which is in communication with each eModule and with the driver input devices, communicates with and independently controls each eModule, by-wire, via the embedded controllers to establish a desired operating mode. Modes may include a two-wheel, four-wheel, diamond, and omni-directional steering modes as well as a park mode. A bumper may enable docking with another vehicle, with shared control over the eModules of the vehicles.

  20. Modular radiochemistry synthesis system

    SciTech Connect

    Satyamurthy, Nagichettiar; Barrio, Jorge R.; Amarasekera, Bernard; Van Dam, Michael R.; Olma, Sebastian; Williams, Dirk; Eddings, Mark; Shen, Clifton Kwang-Fu

    2016-11-01

    A modular chemical production system includes multiple modules for performing a chemical reaction, particularly of radiochemical compounds, from a remote location. One embodiment comprises a reaction vessel including a moveable heat source with the position thereof relative to the reaction vessel being controllable from a remote position. Alternatively the heat source may be fixed in location and the reaction vial is moveable into and out of the heat source. The reaction vessel has one or more sealing plugs, the positioning of which in relationship to the reaction vessel is controllable from a remote position. Also the one or more reaction vessel sealing plugs can include one or more conduits there through for delivery of reactants, gases at atmospheric or an elevated pressure, inert gases, drawing a vacuum and removal of reaction end products to and from the reaction vial, the reaction vial with sealing plug in position being operable at elevated pressures. The modular chemical production system is assembled from modules which can each include operating condition sensors and controllers configured for monitoring and controlling the individual modules and the assembled system from a remote position. Other modules include, but are not limited to a Reagent Storage and Delivery Module, a Cartridge Purification Module, a Microwave Reaction Module, an External QC/Analysis/Purification Interface Module, an Aliquotting Module, an F-18 Drying Module, a Concentration Module, a Radiation Counting Module, and a Capillary Reactor Module.

  1. Quantum modular forms, mock modular forms, and partial theta functions

    NASA Astrophysics Data System (ADS)

    Kimport, Susanna

    Defined by Zagier in 2010, quantum modular forms have been the subject of an explosion of recent research. Many of these results are aimed at discovering examples of these functions, which are defined on the rational numbers and have "nice" modularity properties. Though the subject is in its early stages, numerous results (including Zagier's original examples) show these objects naturally arising from many areas of mathematics as limits of other modular-like functions. One such family of examples is due to Folsom, Ono, and Rhoades, who connected these new objects to partial theta functions (introduced by Rogers in 1917) and mock modular forms (about which there is a rich theory, whose origins date back to Ramanujan in 1920). In this thesis, we build off of the work of Folsom, Ono, and Rhoades by providing an infinite family of quantum modular forms of arbitrary positive half-integral weight. Further, this family of quantum modular forms "glues" mock modular forms to partial theta functions and is constructed from a so-called "universal" mock theta function by extending a method of Eichler and Zagier (originally defined for holomorphic Jacobi forms) into a non-holomorphic setting. In addition to the infinite family, we explore the weight 1/2 and 3/2 functions in more depth. For both of these weights, we are able to explicitly write down the quantum modular form, as well as the corresponding "errors to modularity," which can be shown to be Mordell integrals of specific theta functions and, as a consequence, are real-analytic functions. Finally, we turn our attention to the partial theta functions associated with these low weight examples. Berndt and Kim provide asymptotic expansions for a certain class of partial theta functions as q approaches 1 radially within the unit disk. Here, we extend this work to not only obtain asymptotic expansions for this class of functions as q approaches any root of unity, but also for a certain class of derivatives of these functions

  2. Spacecraft Modularity for Serviceable Satellites

    NASA Technical Reports Server (NTRS)

    Rossetti, Dino; Keer, Beth; Panek, John; Ritter, Bob; Reed, Benjamin; Cepollina, Frank

    2015-01-01

    Spacecraft modularity has been a topic of interest at NASA since the 1970s, when the Multi-­-Mission Modular Spacecraft (MMS) was developed at the Goddard Space Flight Center. Since then, modular concepts have been employed for a variety of spacecraft and, as in the case of the Hubble Space Telescope (HST) and the International Space Station (ISS), have been critical to the success of on-­- orbit servicing. Modularity is even more important for future robotic servicing. Robotic satellite servicing technologies under development by NASA can extend mission life and reduce lifecycle cost and risk. These are optimized when the target spacecraft is designed for servicing, including advanced modularity. This paper will explore how spacecraft design, as demonstrated by the Reconfigurable Operational spacecraft for Science and Exploration (ROSE) spacecraft architecture, and servicing technologies can be developed in parallel to fully take advantage of the promise of both.

  3. Spacecraft Modularity for Serviceable Satellites

    NASA Technical Reports Server (NTRS)

    Reed, Benjamin B.; Rossetti, Dino; Keer, Beth; Panek, John; Cepollina, Frank; Ritter, Robert

    2015-01-01

    Spacecraft modularity has been a topic of interest at NASA since the 1970s, when the Multi-Mission Modular Spacecraft (MMS) was developed at the Goddard Space Flight Center. Since then, modular concepts have been employed for a variety of spacecraft and, as in the case of the Hubble Space Telescope (HST) and the International Space Station (ISS), have been critical to the success of on-orbit servicing. Modularity is even more important for future robotic servicing. Robotic satellite servicing technologies under development by NASA can extend mission life and reduce life-cycle cost and risk. These are optimized when the target spacecraft is designed for servicing, including advanced modularity. This paper will explore how spacecraft design, as demonstrated by the Reconfigurable Operational spacecraft for Science and Exploration (ROSE) spacecraft architecture, and servicing technologies can be developed in parallel to fully take advantage of the promise of both.

  4. Modular Flooring System

    NASA Technical Reports Server (NTRS)

    Thate, Robert

    2012-01-01

    The modular flooring system (MFS) was developed to provide a portable, modular, durable carpeting solution for NASA fs Robotics Alliance Project fs (RAP) outreach efforts. It was also designed to improve and replace a modular flooring system that was too heavy for safe use and transportation. The MFS was developed for use as the flooring for various robotics competitions that RAP utilizes to meet its mission goals. One of these competitions, the FIRST Robotics Competition (FRC), currently uses two massive rolls of broadloom carpet for the foundation of the arena in which the robots are contained during the competition. The area of the arena is approximately 30 by 72 ft (approximately 9 by 22 m). This carpet is very cumbersome and requires large-capacity vehicles, and handling equipment and personnel to transport and deploy. The broadloom carpet sustains severe abuse from the robots during a regular three-day competition, and as a result, the carpet is not used again for competition. Similarly, broadloom carpets used for trade shows at convention centers around the world are typically discarded after only one use. This innovation provides a green solution to this wasteful practice. Each of the flooring modules in the previous system weighed 44 lb (.20 kg). The improvements in the overall design of the system reduce the weight of each module by approximately 22 lb (.10 kg) (50 %), and utilize an improved "module-to-module" connection method that is superior to the previous system. The MFS comprises 4-by-4-ft (.1.2-by- 1.2-m) carpet module assemblies that utilize commercially available carpet tiles that are bonded to a lightweight substrate. The substrate surface opposite from the carpeted surface has a module-to-module connecting interface that allows for the modules to be connected, one to the other, as the modules are constructed. This connection is hidden underneath the modules, creating a smooth, co-planar flooring surface. The modules are stacked and strapped

  5. Comparison between preoperative digital planning and postoperative outcomes in 197 hip endoprosthesis cases using short stem prostheses.

    PubMed

    Höhle, Philip; Schröder, Simon M; Pfeil, Joachim

    2015-01-01

    Preservation of hip geometry is important for treatment success in endoprosthesis implantation. Digital planning can be used to estimate postoperative hip geometry. This study examined whether digital planning accurately predicts surgical outcomes for two femoral neck resecting short stem implants, Mayo® (Zimmer) and Metha® (Aesculap). Preoperative digital planning of the short stem and acetabular cup was performed for 191 patients (197 endoprostheses) with hip osteoarthritis. Digital planning was done with mediCAD II (Hectec) to evaluate types of prosthesis stems and sizes, leg lengthening and offset, and angle of stem inclination within the femur. The predicted values for these parameters were compared to the postoperative measurements. A double coordinate system was developed to measure pelvic and femoral distances separately. Individual scale factors were applied to minimize measurement bias. Implantation of the planned short stem prostheses resulted in a mean femoro-acetabular leg lengthening of 4.2mm (SD 5.8mm) and a mean femoro-acetabular offset-reduction of 4.2mm (SD 5.9mm) in comparison with preoperative planning. Implantation of both stems resulted in increased valgization compared to planning (Metha®, mean 5.4° (SD 3.7°); Mayo®, mean -3.2° (SD 3.4°)). Differences between preoperative planning and postoperative outcomes were greater for femoro-acetabular than for cup-related leg length and offset. On average, leg length was longer than predicted and there was loss of femoro-acetabular offset. Compared with the planning, valgization of the implanted stems was frequently observed. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Modular arctic structures system

    SciTech Connect

    Reusswig, G. H.

    1984-12-04

    A modular and floatable offshore exploration and production platform system for use in shallow arctic waters is disclosed. A concrete base member is floated to the exploration or production site, and ballated into a predredged cavity. The cavity and base are sized to provide a stable horizontal base 30 feet below the mean water/ice plane. An exploration or production platform having a massive steel base is floated to the site and ballasted into position on the base. Together, the platform, base and ballast provide a massive gravity structure that is capable of resisting large ice and wave forces that impinge on the structure. The steel platform has a sloping hourglass profile to deflect horizontal ice loads vertically, and convert the horizontal load to a vertical tensile stress, which assists in breaking the ice as it advances toward the structure.

  7. Modular small hydro configuration

    NASA Astrophysics Data System (ADS)

    1981-09-01

    Smaller sites (those under 750 kilowatts) which previously were not attractive to develop using equipment intended for application at larger scale sites, were the focal point in the conception of a system which utilizes standard industrial components which are generally available within short procurement times. Such components were integrated into a development scheme for sites having 20 feet to 150 feet of head. The modular small hydro configuration maximizes the use of available components and minimizes modification of existing civil works. A key aspect of the development concept is the use of a vertical turbine multistage pump, used in the reverse mode as a hydraulic turbine. The configuration allows for automated operation and control of the hydroelectric facilities with sufficient flexibility for inclusion of potential hydroelectric sites into dispersed storage and generation (DSG) utility grid systems.

  8. Modular error embedding

    DOEpatents

    Sandford, II, Maxwell T.; Handel, Theodore G.; Ettinger, J. Mark

    1999-01-01

    A method of embedding auxiliary information into the digital representation of host data containing noise in the low-order bits. The method applies to digital data representing analog signals, for example digital images. The method reduces the error introduced by other methods that replace the low-order bits with auxiliary information. By a substantially reverse process, the embedded auxiliary data can be retrieved easily by an authorized user through use of a digital key. The modular error embedding method includes a process to permute the order in which the host data values are processed. The method doubles the amount of auxiliary information that can be added to host data values, in comparison with bit-replacement methods for high bit-rate coding. The invention preserves human perception of the meaning and content of the host data, permitting the addition of auxiliary data in the amount of 50% or greater of the original host data.

  9. Modular Optical PDV System

    SciTech Connect

    Araceli Rutkowski, David Esquibel

    2008-12-11

    A modular optical photon Doppler velocimetry (PDV) detector system has been developed by using readily available optical components with a 20-GHz Miteq optical detector into eight channels of single-wide modules integrated into a 3U rack unit (1U = 1.75 inches) with a common power supply. Optical fibers were precisely trimmed, welded, and timed within each unit. This system has been used to collect dynamic velocity data on various physics experiments. An optical power meter displays the laser input power to the module and optical power at the detector. An adjustable micro-electromechanical system (MEMS) optical attenuator is used to adjust the amount of unshifted light entering the detector. Front panel LEDs show the presence of power to the module. A fully loaded chassis with eight channels consumes 45 watts of power. Each chassis requires 1U spacing above and below for heat management. Modules can be easily replaced.

  10. Modular weapon control unit

    SciTech Connect

    Boccabella, M.F.; McGovney, G.N.

    1997-01-01

    The goal of the Modular Weapon Control Unit (MWCU) program was to design and develop a reconfigurable weapon controller (programmer/sequencer) that can be adapted to different weapon systems based on the particular requirements for that system. Programmers from previous systems are conceptually the same and perform similar tasks. Because of this commonality and the amount of re-engineering necessary with the advent of every new design, the idea of a modular, adaptable system has emerged. Also, the controller can be used in more than one application for a specific weapon system. Functionality has been divided into a Processor Module (PM) and an Input/Output Module (IOM). The PM will handle all operations that require calculations, memory, and timing. The IOM will handle interfaces to the rest of the system, input level shifting, output drive capability, and detection of interrupt conditions. Configuration flexibility is achieved in two ways. First, the operation of the PM is determined by a surface mount Read-Only Memory (ROM). Other surface-mount components can be added or neglected as necessary for functionality. Second, IOMs consist of configurable input buffers, configurable output drivers, and configurable interrupt generation. Further, these modules can be added singly or in groups to a Processor Module to achieve the required I/O configuration. The culmination of this LDRD was the building of both Processor Module and Input/Output Module. The MWCU was chosen as a test system to evaluate Low-Temperature Co-fired Ceramic (LTCC) technology, desirable for high component density and good thermal characteristics.

  11. Midterm results of a femoral stem with a modular neck design: clinical outcomes and metal ion analysis.

    PubMed

    Silverton, Craig D; Jacobs, Joshua J; Devitt, Jeffrey W; Cooper, H John

    2014-09-01

    Modular neck femoral stems have a higher-than-anticipated rate of failure in registry results, but large single-center cohort studies are lacking. This is a retrospective cohort of 152 hips implanted with a single titanium stem with a modular titanium neck, presenting clinical, radiographic, and metal ion results at a mean 4.5-year follow-up. Five hips were revised during the study period, for an overall Kaplan-Meier survival of 0.894 at 8 years. There was one modular neck fracture (0.66%), but others demonstrated corrosion or adverse tissue reaction. Serum metal levels demonstrated wide variability. Despite good clinical results in the majority of patients, we confirmed an increased rate of femoral revision at mid-term follow-up, and therefore urge caution in the use of this particular stem design. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Titanium Nitride Cermets

    DTIC Science & Technology

    1952-07-01

    7696i ’-Brewer, L., et al. Thermodynamic and Physical Properties of Nitrides. Carbides, Sulfides, i1licides, and Phosphides, Chemistry and Metallurgy of...12 Referen eCs 0 . ...................... • • • 14 WADC TR 52-155 iv LIST OF TABLES I Properties of Titanium Nitride Bodies...15 II Properties of Titanium Nitride-Nickel Bodies............16 III Properties of Titanium Nitride Cermets with Nickel,..... 17 Cobalt, and

  13. Influence of the fixation region of a press-fit hip endoprosthesis on the stress-strain state of the "bone-implant" system.

    PubMed

    Levadnyi, Ievgen; Awrejcewicz, Jan; Goethel, Márcio Fagundes; Loskutov, Alexander

    2017-05-01

    Although significant progress has been made in the development of total hip replacement, behaviour of the femoral component of an endoprosthesis in relation to the type of its fixation in the bone is still not fully understood. In this paper, behaviour of the femoral bone and the stem prosthesis is studied taking into account different types of prosthesis fixation in the medullary canal of the femur under the action of functional loads. For an analysis, a three-dimensional model of a femur has been developed based on the results of a computed tomography. The stress-strain state governing behaviour of the femoral bone and the stem prosthesis has been estimated with the use of the finite element method (FEM). The FEM analysis has shown that for the diaphyseal fixation, the area of contact between the surface of the endoprosthesis and the bone is insufficient and leads to large stresses in the implant accompanied by stress concentration in the distal femur. An increase in the area of contact between the implant and the bone raises the stiffness of the "bone-implant" system, which, in turn, reduces stresses in the implant. The applied metaphyseal-type fixation yielded an improvement of results regarding behaviour of the femoral bone and the stem prosthesis. Namely, the study yielded the distribution of stress in the bone similar to the physiological stress state. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Numerical simulations of human tibia osteosynthesis using modular plates based on Nitinol staples.

    PubMed

    Tarniţă, Daniela; Tarniţă, D N; Popa, D; Grecu, D; Tarniţă, Roxana; Niculescu, D; Cismaru, F

    2010-01-01

    The shape memory alloys exhibit a number of remarkable properties, which open new possibilities in engineering and more specifically in biomedical engineering. The most important alloy used in biomedical applications is NiTi. This alloy combines the characteristics of the shape memory effect and superelasticity with excellent corrosion resistance, wear characteristics, mechanical properties and a good biocompatibility. These properties make it an ideal biological engineering material, especially in orthopedic surgery and orthodontics. In this work, modular plates for the osteosynthesis of the long bones fractures are presented. The proposed modular plates are realized from identical modules, completely interchangeable, made of titanium or stainless steel having as connecting elements U-shaped staples made of Nitinol. Using computed tomography (CT) images to provide three-dimensional geometric details and SolidWorks software package, the three dimensional virtual models of the tibia bone and of the modular plates are obtained. The finite element models of the tibia bone and of the modular plate are generated. For numerical simulation, VisualNastran software is used. Finally, displacements diagram, von Misses strain diagram, for the modular plate and for the fractured tibia and modular plate ensemble are obtained.

  15. Spacecraft Modularity for Serviceable Satellites

    NASA Technical Reports Server (NTRS)

    Rossetti, Dino; Keer, Beth; Panek, John; Reed, Benjamin; Cepollina, Frank; Ritter, Robert

    2015-01-01

    Satellite servicing has been a proven capability of NASA since the first servicing missions in the 1980s with astronauts on the space shuttle. This capability enabled the on-orbit assembly of the International Space Station (ISS) and saved the Hubble Space Telescope (HST) mission following the discovery of the flawed primary mirror. The effectiveness and scope of servicing opportunities, especially using robotic servicers, is a function of how cooperative a spacecraft is. In this paper, modularity will be presented as a critical design aspect for a spacecraft that is cooperative from a servicing perspective. Different features of modularity are discussed using examples from HST and the Multimission Modular Spacecraft (MMS) program from the 1980s and 1990s. The benefits of modularity will be presented including those directly related to servicing and those outside of servicing including reduced costs and increased flexibility. The new Reconfigurable Operational spacecraft for Science and Exploration (ROSE) concept is introduced as an affordable implementation of modularity that provides cost savings and flexibility. Key aspects of the ROSE architecture are discussed such as the module design and the distributed avionics architecture. The ROSE concept builds on the experience from MMS and due to its modularity, would be highly suitable as a future client for on-orbit servicing.

  16. The Modular Adaptive Ribosome.

    PubMed

    Yadav, Anupama; Radhakrishnan, Aparna; Panda, Anshuman; Singh, Amartya; Sinha, Himanshu; Bhanot, Gyan

    2016-01-01

    The ribosome is an ancient machine, performing the same function across organisms. Although functionally unitary, recent experiments suggest specialized roles for some ribosomal proteins. Our central thesis is that ribosomal proteins function in a modular fashion to decode genetic information in a context dependent manner. We show through large data analyses that although many ribosomal proteins are essential with consistent effect on growth in different conditions in yeast and similar expression across cell and tissue types in mice and humans, some ribosomal proteins are used in an environment specific manner. The latter set of variable ribosomal proteins further function in a coordinated manner forming modules, which are adapted to different environmental cues in different organisms. We show that these environment specific modules of ribosomal proteins in yeast have differential genetic interactions with other pathways and their 5'UTRs show differential signatures of selection in yeast strains, presumably to facilitate adaptation. Similarly, we show that in higher metazoans such as mice and humans, different modules of ribosomal proteins are expressed in different cell types and tissues. A clear example is nervous tissue that uses a ribosomal protein module distinct from the rest of the tissues in both mice and humans. Our results suggest a novel stratification of ribosomal proteins that could have played a role in adaptation, presumably to optimize translation for adaptation to diverse ecological niches and tissue microenvironments.

  17. The Modular Adaptive Ribosome

    PubMed Central

    Yadav, Anupama; Radhakrishnan, Aparna; Panda, Anshuman; Singh, Amartya; Sinha, Himanshu; Bhanot, Gyan

    2016-01-01

    The ribosome is an ancient machine, performing the same function across organisms. Although functionally unitary, recent experiments suggest specialized roles for some ribosomal proteins. Our central thesis is that ribosomal proteins function in a modular fashion to decode genetic information in a context dependent manner. We show through large data analyses that although many ribosomal proteins are essential with consistent effect on growth in different conditions in yeast and similar expression across cell and tissue types in mice and humans, some ribosomal proteins are used in an environment specific manner. The latter set of variable ribosomal proteins further function in a coordinated manner forming modules, which are adapted to different environmental cues in different organisms. We show that these environment specific modules of ribosomal proteins in yeast have differential genetic interactions with other pathways and their 5’UTRs show differential signatures of selection in yeast strains, presumably to facilitate adaptation. Similarly, we show that in higher metazoans such as mice and humans, different modules of ribosomal proteins are expressed in different cell types and tissues. A clear example is nervous tissue that uses a ribosomal protein module distinct from the rest of the tissues in both mice and humans. Our results suggest a novel stratification of ribosomal proteins that could have played a role in adaptation, presumably to optimize translation for adaptation to diverse ecological niches and tissue microenvironments. PMID:27812193

  18. Modular Approach to Spintronics.

    PubMed

    Camsari, Kerem Yunus; Ganguly, Samiran; Datta, Supriyo

    2015-06-11

    There has been enormous progress in the last two decades, effectively combining spintronics and magnetics into a powerful force that is shaping the field of memory devices. New materials and phenomena continue to be discovered at an impressive rate, providing an ever-increasing set of building blocks that could be exploited in designing transistor-like functional devices of the future. The objective of this paper is to provide a quantitative foundation for this building block approach, so that new discoveries can be integrated into functional device concepts, quickly analyzed and critically evaluated. Through careful benchmarking against available theory and experiment we establish a set of elemental modules representing diverse materials and phenomena. These elemental modules can be integrated seamlessly to model composite devices involving both spintronic and nanomagnetic phenomena. We envision the library of modules to evolve both by incorporating new modules and by improving existing modules as the field progresses. The primary contribution of this paper is to establish the ground rules or protocols for a modular approach that can build a lasting bridge between materials scientists and circuit designers in the field of spintronics and nanomagnetics.

  19. Modular Isotopic Thermoelectric Generator

    SciTech Connect

    Schock, Alfred

    1981-04-03

    Advanced RTG concepts utilizing improved thermoelectric materials and converter concepts are under study at Fairchild for DOE. The design described here is based on DOE's newly developed radioisotope heat source, and on an improved silicon-germanium material and a multicouple converter module under development at Syncal. Fairchild's assignment was to combine the above into an attractive power system for use in space, and to assess the specific power and other attributes of that design. The resultant design is highly modular, consisting of standard RTG slices, each producing ~24 watts at the desired output voltage of 28 volt. Thus, the design could be adapted to various space missions over a wide range of power levels, with little or no redesign. Each RTG slice consists of a 250-watt heat source module, eight multicouple thermoelectric modules, and standard sections of insulator, housing, radiator fins, and electrical circuit. The design makes it possible to check each thermoelectric module for electrical performance, thermal contact, leaktightness, and performance stability, after the generator is fully assembled; and to replace any deficient modules without disassembling the generator or perturbing the others. The RTG end sections provide the spring-loaded supports required to hold the free-standing heat source stack together during launch vibration. Details analysis indicates that the design offers a substantial improvement in specific power over the present generator of RTGs, using the same heat source modules. There are three copies in the file.

  20. Modular Approach to Spintronics

    PubMed Central

    Camsari, Kerem Yunus; Ganguly, Samiran; Datta, Supriyo

    2015-01-01

    There has been enormous progress in the last two decades, effectively combining spintronics and magnetics into a powerful force that is shaping the field of memory devices. New materials and phenomena continue to be discovered at an impressive rate, providing an ever-increasing set of building blocks that could be exploited in designing transistor-like functional devices of the future. The objective of this paper is to provide a quantitative foundation for this building block approach, so that new discoveries can be integrated into functional device concepts, quickly analyzed and critically evaluated. Through careful benchmarking against available theory and experiment we establish a set of elemental modules representing diverse materials and phenomena. These elemental modules can be integrated seamlessly to model composite devices involving both spintronic and nanomagnetic phenomena. We envision the library of modules to evolve both by incorporating new modules and by improving existing modules as the field progresses. The primary contribution of this paper is to establish the ground rules or protocols for a modular approach that can build a lasting bridge between materials scientists and circuit designers in the field of spintronics and nanomagnetics. PMID:26066079

  1. Sealing glasses for titanium and titanium alloys

    DOEpatents

    Brow, Richard K.; McCollister, Howard L.; Phifer, Carol C.; Day, Delbert E.

    1997-01-01

    Barium lanthanoborate sealing-glass compositions are provided comprising various combinations (in terms of mole-%) of boron oxide (B.sub.2 O.sub.3), barium oxide (BaO), lanthanum oxide (La.sub.2 O.sub.3), and at least one other oxide selected from the group consisting of aluminum oxide (Al.sub.2 O.sub.3), calcium oxide (CaO), lithium oxide (Li.sub.2 O), sodium oxide (Na.sub.2 O), silicon dioxide (SiO.sub.2), or titanium dioxide (TiO.sub.2). These sealing-glass compositions are useful for forming hermetic glass-to-metal seals with titanium and titanium alloys having an improved aqueous durability and favorable sealing characteristics. Examples of the sealing-glass compositions are provided having coefficients of thermal expansion about that of titanium or titanium alloys, and with sealing temperatures less than about 900.degree. C., and generally about 700.degree.-800.degree. C. The barium lanthanoborate sealing-glass compositions are useful for components and devices requiring prolonged exposure to moisture or water, and for implanted biomedical devices (e.g. batteries, pacemakers, defibrillators, pumps).

  2. Sealing glasses for titanium and titanium alloys

    DOEpatents

    Brow, R.K.; McCollister, H.L.; Phifer, C.C.; Day, D.E.

    1997-07-15

    Barium lanthanoborate sealing-glass compositions are provided comprising various combinations (in terms of mole-%) of boron oxide (B{sub 2}O{sub 3}), barium oxide (BaO), lanthanum oxide (La{sub 2}O{sub 3}), and at least one other oxide selected from the group consisting of aluminum oxide (Al{sub 2}O{sub 3}), calcium oxide (CaO), lithium oxide (Li{sub 2}O), sodium oxide (Na{sub 2}O), silicon dioxide (SiO{sub 2}), or titanium dioxide (TiO{sub 2}). These sealing-glass compositions are useful for forming hermetic glass-to-metal seals with titanium and titanium alloys having an improved aqueous durability and favorable sealing characteristics. Examples of the sealing-glass compositions are provided having coefficients of thermal expansion about that of titanium or titanium alloys, and with sealing temperatures less than about 900 C, and generally about 700--800 C. The barium lanthanoborate sealing-glass compositions are useful for components and devices requiring prolonged exposure to moisture or water, and for implanted biomedical devices (e.g. batteries, pacemakers, defibrillators, pumps). 1 fig.

  3. Sprayable titanium composition

    DOEpatents

    Tracy, Chester E.; Kern, Werner; Vibronek, Robert D.

    1980-01-01

    The addition of 2-ethyl-1-hexanol to an organometallic titanium compound dissolved in a diluent and optionally containing a lower aliphatic alcohol spreading modifier, produces a solution that can be sprayed onto a substrate and cured to form an antireflection titanium oxide coating having a refractive index of from about 2.0 to 2.2.

  4. Preliminary Experience with the GORE(®) EXCLUDER(®) Iliac Branch Endoprosthesis for Common Iliac Aneurysm Endovascular Treatment.

    PubMed

    Millon, Antoine; Della Schiava, Nellie; Arsicot, Matthieu; De Lambert, Alberic; Feugier, Patrick; Magne, Jean Luc; Lermusiaux, Patrick

    2016-05-01

    The aim of this study is to assess the safety and the short-term results of endovascular treatment of common iliac artery (CIA) aneurysms using the new GORE EXCLUDER iliac branch endoprosthesis (IBE) device. The study is a retrospective with prospective follow-up nonrandomized, single-arm evaluation. Patients with a CIA aneurysm (diameter >30 mm) extending to the iliac bifurcation underwent endovascular treatment with the Gore IBE. Anatomic and procedural data were collected. Computed tomography angiography (CTA) was performed within the 30 days after the procedure and every 6 month. Thirty-day and at least 6-months outcomes were investigated. From February 2014 to December 2014, 10 male patients with aneurysmal CIA (mean age 75 years old) underwent consecutive endovascular treatment with the Gore IBE. The CIA aneurysm (mean diameter 43.2 mm, range 32-49) treated with the Gore IBE was associated with an abdominal aortic aneurysm (AAA) in 5 patients. One patient had a previous AAA open repair. CIA aneurysm was bilateral in 5 patients. Preliminary procedure of internal iliac artery embolization was performed in 3 patients. Technical success rate of the Gore IBE implantation was 100% with a median fluoroscopy time of 35 min (range 12-64, ±16) and median contrast load of 150 mL (range 100-250, ±45). No perioperative complications were observed. Median length of stay was 4 days (range 3-7, ±2). One aortic type Ia endoleak was observed on the postoperative CT scan requiring an aortic extension at day 3. Branch patency was observed in all 10 patients at 1 month and 9 patients at 6 month. All CIA aneurysms were excluded without type Ib or type III endoleak. The technical success and short-term results demonstrate encouraging results and clinical benefits of the new GORE EXCLUDER IBE. A longer follow-up is needed to assess midterm and long-term results. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Fatigue fracture in dual modular revision total hip arthroplasty stems: failure analysis and computed tomography diagnostics in two cases.

    PubMed

    Norman, Pontus; Iyengar, Srinivasan; Svensson, Ingrid; Flivik, Gunnar

    2014-04-01

    We report on two patients with fracture of a modular, tapered and distally fixed, uncemented titanium revision hip stem, not previously described. A failure analysis revealed that the cause of the fractures was the development of fatigue cracks in the mid-stem cobalt-chromium modular junction ending in corrosion-fatigue failure. No material defects or stress risers were found in any of the implants. The diameter of the mid-stem modular junction might be undersized for use in heavy and active patients. We also report a new way of detecting an undisplaced fracture at the modular junction, using the scout image from a computed tomography (CT) scan; a technique that can be used when plain radiographs are inconclusive.

  6. Titanium and titanium alloys as dental materials.

    PubMed

    Lautenschlager, E P; Monaghan, P

    1993-06-01

    Because of light weight, high strength to weight ratio, low modulus of elasticity, and excellent corrosion resistance, titanium and some of its alloys have been important materials for the aerospace industry since the 1950s. Now, with the additional advantages of excellent biocompatibility, good local spot weldability, and easy shaping and finishing by a number of mechanical and electrochemical processes, these materials are finding uses in dental applications, such as implants and restorative castings. Although more research is still needed in areas such as development of optimal casting investments, porcelain veneering systems, device designs, and controlled biological responses, the present and future uses of titanium appear bright for dentistry.

  7. Modular Stirling Radioisotope Generator

    NASA Technical Reports Server (NTRS)

    Schmitz, Paul C.; Mason, Lee S.; Schifer, Nicholas A.

    2015-01-01

    High efficiency radioisotope power generators will play an important role in future NASA space exploration missions. Stirling Radioisotope Generators (SRG) have been identified as a candidate generator technology capable of providing mission designers with an efficient, high specific power electrical generator. SRGs high conversion efficiency has the potential to extend the limited Pu-238 supply when compared with current Radioisotope Thermoelectric Generators (RTG). Due to budgetary constraints, the Advanced Stirling Radioisotope Generator (ASRG) was canceled in the fall of 2013. Over the past year a joint study by NASA and DOE called the Nuclear Power Assessment Study (NPAS) recommended that Stirling technologies continue to be explored. During the mission studies of the NPAS, spare SRGs were sometimes required to meet mission power system reliability requirements. This led to an additional mass penalty and increased isotope consumption levied on certain SRG-based missions. In an attempt to remove the spare power system, a new generator architecture is considered which could increase the reliability of a Stirling generator and provide a more fault-tolerant power system. This new generator called the Modular Stirling Radioisotope Generator (MSRG) employs multiple parallel Stirling convertor/controller strings, all of which share the heat from the General Purpose Heat Source (GPHS) modules. For this design, generators utilizing one to eight GPHS modules were analyzed, which provide about 50 to 450 watts DC to the spacecraft, respectively. Four Stirling convertors are arranged around each GPHS module resulting in from 4 to 32 Stirling/controller strings. The convertors are balanced either individually or in pairs, and are radiatively coupled to the GPHS modules. Heat is rejected through the housing/radiator which is similar in construction to the ASRG. Mass and power analysis for these systems indicate that specific power may be slightly lower than the ASRG and

  8. Modular Stirling Radioisotope Generator

    NASA Technical Reports Server (NTRS)

    Schmitz, Paul C.; Mason, Lee S.; Schifer, Nicholas A.

    2016-01-01

    High-efficiency radioisotope power generators will play an important role in future NASA space exploration missions. Stirling Radioisotope Generators (SRGs) have been identified as a candidate generator technology capable of providing mission designers with an efficient, high-specific-power electrical generator. SRGs high conversion efficiency has the potential to extend the limited Pu-238 supply when compared with current Radioisotope Thermoelectric Generators (RTGs). Due to budgetary constraints, the Advanced Stirling Radioisotope Generator (ASRG) was canceled in the fall of 2013. Over the past year a joint study by NASA and the Department of Energy (DOE) called the Nuclear Power Assessment Study (NPAS) recommended that Stirling technologies continue to be explored. During the mission studies of the NPAS, spare SRGs were sometimes required to meet mission power system reliability requirements. This led to an additional mass penalty and increased isotope consumption levied on certain SRG-based missions. In an attempt to remove the spare power system, a new generator architecture is considered, which could increase the reliability of a Stirling generator and provide a more fault-tolerant power system. This new generator called the Modular Stirling Radioisotope Generator (MSRG) employs multiple parallel Stirling convertor/controller strings, all of which share the heat from the General Purpose Heat Source (GPHS) modules. For this design, generators utilizing one to eight GPHS modules were analyzed, which provided about 50 to 450 W of direct current (DC) to the spacecraft, respectively. Four Stirling convertors are arranged around each GPHS module resulting in from 4 to 32 Stirling/controller strings. The convertors are balanced either individually or in pairs, and are radiatively coupled to the GPHS modules. Heat is rejected through the housing/radiator, which is similar in construction to the ASRG. Mass and power analysis for these systems indicate that specific

  9. Three-year results of the VIBRANT trial of VIABAHN endoprosthesis versus bare nitinol stent implantation for complex superficial femoral artery occlusive disease.

    PubMed

    Geraghty, Patrick J; Mewissen, Mark W; Jaff, Michael R; Ansel, Gary M

    2013-08-01

    The predominant mode of bare nitinol stent failure is diffuse in-stent restenosis, and failure rates correlate to the length and complexity of the treated lesion. Addition of an expanded polytetrafluoroethylene lining to a nitinol stent frame, as found in the VIABAHN endoprosthesis, mitigates the ingrowth of intimal hyperplasia. We compared the long-term outcomes of complex superficial femoral artery disease intervention using the VIABAHN endoprosthesis to those obtained with bare nitinol stent implantation. One hundred forty-eight patients with symptomatic complex superficial femoral artery disease (TransAtlantic Inter-Society Consensus I class C and D lesions, accompanied by intermittent claudication or ischemic rest pain) were randomized to endovascular intervention using either bare nitinol stent implantation (76 patients) or nonheparin-bonded VIABAHN endoprosthesis deployment (72 patients). Patency, limb hemodynamics, and quality of life were evaluated at 1, 6, 12, 24, and 36 months following intervention. The average treated lesion measured 18 ± 8 cm in length, and 58.8% of lesions displayed segmental or complete occlusion. At 3 years, primary patency rates (defined by peak systolic velocity ratio ≤ 2.0 and no target lesion revascularization) did not significantly differ between patients treated with the VIABAHN stent graft and those who received a bare nitinol stent (24.2% vs 25.9%; P = .392). Stent fractures were significantly more common in bare nitinol stents (50.0%) than in the VIABAHN endoprostheses (2.6%). Primary-assisted patency rates were higher in those receiving bare nitinol stents than the VIABAHN stent graft (88.8% vs 69.8%; P = .04), although secondary patency rates did not differ between bare nitinol stent and stent graft recipients (89.3% vs 79.5%; P = .304). There were no instances of procedure-related mortality or amputation. The hemodynamic improvement and quality measures improved equally in both groups. The long-term outcomes of

  10. Modular Power Standard for Space Explorations Missions

    NASA Technical Reports Server (NTRS)

    Oeftering, Richard C.; Gardner, Brent G.

    2016-01-01

    Future human space exploration will most likely be composed of assemblies of multiple modular spacecraft elements with interconnected electrical power systems. An electrical system composed of a standardized set modular building blocks provides significant development, integration, and operational cost advantages. The modular approach can also provide the flexibility to configure power systems to meet the mission needs. A primary goal of the Advanced Exploration Systems (AES) Modular Power System (AMPS) project is to establish a Modular Power Standard that is needed to realize these benefits. This paper is intended to give the space exploration community a "first look" at the evolving Modular Power Standard and invite their comments and technical contributions.

  11. Eigenvalue Spectra of Modular Networks

    NASA Astrophysics Data System (ADS)

    Peixoto, Tiago P.

    2013-08-01

    A large variety of dynamical processes that take place on networks can be expressed in terms of the spectral properties of some linear operator which reflects how the dynamical rules depend on the network topology. Often, such spectral features are theoretically obtained by considering only local node properties, such as degree distributions. Many networks, however, possess large-scale modular structures that can drastically influence their spectral characteristics and which are neglected in such simplified descriptions. Here, we obtain in a unified fashion the spectrum of a large family of operators, including the adjacency, Laplacian, and normalized Laplacian matrices, for networks with generic modular structure, in the limit of large degrees. We focus on the conditions necessary for the merging of the isolated eigenvalues with the continuous band of the spectrum, after which the planted modular structure can no longer be easily detected by spectral methods. This is a crucial transition point which determines when a modular structure is strong enough to affect a given dynamical process. We show that this transition happens in general at different points for the different matrices, and hence the detectability threshold can vary significantly, depending on the operator chosen. Equivalently, the sensitivity to the modular structure of the different dynamical processes associated with each matrix will be different, given the same large-scale structure present in the network. Furthermore, we show that, with the exception of the Laplacian matrix, the different transitions coalesce into the same point for the special case where the modules are homogeneous but separate otherwise.

  12. Product modular design incorporating preventive maintenance issues

    NASA Astrophysics Data System (ADS)

    Gao, Yicong; Feng, Yixiong; Tan, Jianrong

    2016-03-01

    Traditional modular design methods lead to product maintenance problems, because the module form of a system is created according to either the function requirements or the manufacturing considerations. For solving these problems, a new modular design method is proposed with the considerations of not only the traditional function related attributes, but also the maintenance related ones. First, modularity parameters and modularity scenarios for product modularity are defined. Then the reliability and economic assessment models of product modularity strategies are formulated with the introduction of the effective working age of modules. A mathematical model used to evaluate the difference among the modules of the product so that the optimal module of the product can be established. After that, a multi-objective optimization problem based on metrics for preventive maintenance interval different degrees and preventive maintenance economics is formulated for modular optimization. Multi-objective GA is utilized to rapidly approximate the Pareto set of optimal modularity strategy trade-offs between preventive maintenance cost and preventive maintenance interval difference degree. Finally, a coordinate CNC boring machine is adopted to depict the process of product modularity. In addition, two factorial design experiments based on the modularity parameters are constructed and analyzed. These experiments investigate the impacts of these parameters on the optimal modularity strategies and the structure of module. The research proposes a new modular design method, which may help to improve the maintainability of product in modular design.

  13. Modular process modeling for OPC

    NASA Astrophysics Data System (ADS)

    Keck, M. C.; Bodendorf, C.; Schmidtling, T.; Schlief, R.; Wildfeuer, R.; Zumpe, S.; Niehoff, M.

    2007-03-01

    Modular OPC modeling, describing mask, optics, resist and etch processes separately is an approach to keep efforts for OPC manageable. By exchanging single modules of a modular OPC model, a fast response to process changes during process development is possible. At the same time efforts can be reduced, since only single modular process steps have to be re-characterized as input for OPC modeling as the process is adjusted and optimized. Commercially available OPC tools for full chip processing typically make use of semi-empirical models. The goal of our work is to investigate to what extent these OPC tools can be applied for modeling of single process steps as separate modules. For an advanced gate level process we analyze the modeling accuracy over different process conditions (focus and dose) when combining models for each process step - optics, resist and etch - for differing single processes to a model describing the total process.

  14. Modular assembly of optical nanocircuits.

    PubMed

    Shi, Jinwei; Monticone, Francesco; Elias, Sarah; Wu, Yanwen; Ratchford, Daniel; Li, Xiaoqin; Alù, Andrea

    2014-05-29

    A key element enabling the microelectronic technology advances of the past decades has been the conceptualization of complex circuits with versatile functionalities as being composed of the proper combination of basic 'lumped' circuit elements (for example, inductors and capacitors). In contrast, modern nanophotonic systems are still far from a similar level of sophistication, partially because of the lack of modularization of their response in terms of basic building blocks. Here we demonstrate the design, assembly and characterization of relatively complex photonic nanocircuits by accurately positioning a number of metallic and dielectric nanoparticles acting as modular lumped elements. The nanoparticle clusters produce the desired spectral response described by simple circuit rules and are shown to be dynamically reconfigurable by modifying the direction or polarization of impinging signals. Our work represents an important step towards extending the powerful modular design tools of electronic circuits into nanophotonic systems.

  15. Modular multichannel surface plasmon spectrometer

    NASA Astrophysics Data System (ADS)

    Neuert, G.; Kufer, S.; Benoit, M.; Gaub, H. E.

    2005-05-01

    We have developed a modular multichannel surface plasmon resonance (SPR) spectrometer on the basis of a commercially available hybrid sensor chip. Due to its modularity this inexpensive and easy to use setup can readily be adapted to different experimental environments. High temperature stability is achieved through efficient thermal coupling of individual SPR units. With standard systems the performance of the multichannel instrument was evaluated. The absorption kinetics of a cysteamine monolayer, as well as the concentration dependence of the specific receptor-ligand interaction between biotin and streptavidin was measured.

  16. Modular multivariable control improves hydrocracking

    SciTech Connect

    Chia, T.L.; Lefkowitz, I.; Tamas, P.D.

    1996-10-01

    Modular multivariable control (MMC), a system of interconnected, single process variable controllers, can be a user-friendly, reliable and cost-effective alternative to centralized, large-scale multivariable control packages. MMC properties and features derive directly from the properties of the coordinated controller which, in turn, is based on internal model control technology. MMC was applied to a hydrocracking unit involving two process variables and three controller outputs. The paper describes modular multivariable control, MMC properties, tuning considerations, application at the DCS level, constraints handling, and process application and results.

  17. Inherent controllability in modular ALMRs

    SciTech Connect

    Sackett, J.I.; Sevy, R.H.; Wei, T.Y.C.

    1989-01-01

    As part of recent development efforts on advanced reactor designs ANL has proposed the IFR (Integral Fast Reactor) concept. The IFR concept is currently being applied to modular sized reactors which would be built in multiple power paks together with an integrated fuel cycle facility. It has been amply demonstrated that the concept as applied to the modular designs has significant advantages in regard to ATWS transients. Attention is now being focussed on determining whether or not those advantages deriving from the traits of the IFR can be translated to the operational/DBA (design basis accident) class of transients. 5 refs., 3 figs., 3 tabs.

  18. Modular Firewalls for Storage Areas

    NASA Technical Reports Server (NTRS)

    Fedor, O. H.; Owens, L. J.

    1986-01-01

    Giant honeycomb structures assembled in modular units. Flammable materials stored in cells. Walls insulated with firebrick to prevent spread of fire among cells. Portable, modular barrier withstands heat of combustion for limited time and confines combustion products horizontally to prevent fire from spreading. Barrier absorbs heat energy by ablation and not meant to be reused. Designed to keep fires from spreading among segments of solid rocket propellant in storage, barrier erected between storage units of other flammable or explosive materials; tanks of petroleum or liquid natural gas. Barrier adequate for most industrial purposes.

  19. Electroplating on titanium alloy

    NASA Technical Reports Server (NTRS)

    Lowery, J. R.

    1971-01-01

    Activation process forms adherent electrodeposits of copper, nickel, and chromium on titanium alloy. Good adhesion of electroplated deposits is obtained by using acetic-hydrofluoric acid anodic activation process.

  20. Prospective, multicenter study of endovascular repair of aortoiliac and iliac aneurysms using the Gore Iliac Branch Endoprosthesis.

    PubMed

    Schneider, Darren B; Matsumura, Jon S; Lee, Jason T; Peterson, Brian G; Chaer, Rabih A; Oderich, Gustavo S

    2017-09-01

    The GORE EXCLUDER Iliac Branch Endoprosthesis (IBE; W. L. Gore and Associates, Flagstaff, Ariz) is an iliac branch stent graft system designed to preserve internal iliac artery perfusion during endovascular repair of aortoiliac aneurysms (AIAs) and common iliac artery (CIA) aneurysms (CIAAs). We report the 6-month primary end point results of the IBE 12-04 United States pivotal trial for endovascular treatment of AIAs and CIAAs using the IBE device. The trial prospectively enrolled 63 patients with AIA or CIAA who underwent implantation of the IBE device at 28 centers in the United States from 2013 to 2015. All patients underwent placement of a single IBE device. Twenty-two patients (34.9%) with bilateral CIAs were enrolled after undergoing staged coil or plug embolization (21 of 22) or surgical revascularization (1 of 22) of the contralateral internal iliac artery. Follow-up at 30 days and 6 months included clinical assessment and computed tomography angiography evaluation as assessed by an independent core laboratory. The primary effectiveness end point was freedom from IBE limb occlusion and reintervention for type I or III endoleak and ≥60% stenosis at 6 months, and the secondary effectiveness end point was freedom from new onset of buttock claudication on the IBE side at 6 months. Mean CIA diameter on the IBE side was 41.0 ± 11.4 mm (range, 25.2-76.3 mm). There were no procedural deaths, and technical success, defined as successful deployment and patency of all IBE components and freedom from type I or III endoleak, was 95.2% (60 of 63). Data for 61 patients were available for primary and secondary effectiveness end point analysis. Internal iliac limb patency was 95.1% (58 of 61), and no new type I or III endoleaks or device migrations were observed at 6 months. The three patients with loss of internal iliac limb patency were asymptomatic, and freedom from new-onset buttock claudication on the IBE side was 100% at 6 months. New-onset buttock

  1. Modularity in Cognition: Framing the Debate

    ERIC Educational Resources Information Center

    Barrett, H. Clark; Kurzban, Robert

    2006-01-01

    Modularity has been the subject of intense debate in the cognitive sciences for more than 2 decades. In some cases, misunderstandings have impeded conceptual progress. Here the authors identify arguments about modularity that either have been abandoned or were never held by proponents of modular views of the mind. The authors review arguments that…

  2. 47 CFR 15.212 - Modular transmitters.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Modular transmitters. 15.212 Section 15.212 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators § 15.212 Modular transmitters. (a) Single modular transmitters consist of a completely...

  3. 47 CFR 15.212 - Modular transmitters.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Modular transmitters. 15.212 Section 15.212 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators § 15.212 Modular transmitters. (a) Single modular transmitters consist of a completely...

  4. 47 CFR 15.212 - Modular transmitters.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Modular transmitters. 15.212 Section 15.212 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators § 15.212 Modular transmitters. (a) Single modular transmitters consist of a completely...

  5. 47 CFR 15.212 - Modular transmitters.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false Modular transmitters. 15.212 Section 15.212 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Intentional Radiators § 15.212 Modular transmitters. (a) Single modular transmitters consist of a completely...

  6. 48 CFR 3417.70 - Modular contracting.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 7 2013-10-01 2012-10-01 true Modular contracting. 3417... REGULATION CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Modular Contracting 3417.70 Modular contracting. (a) FSA—May incrementally conduct successive procurements of modules of overall...

  7. The Modular Mind and Intrapersonal Communication Processes.

    ERIC Educational Resources Information Center

    Stacks, Don W.

    Based on a prior model on modularity of the brain, a new modular model of intrapersonal communication was developed which focuses on brain processing, encompassing both the structures and the functions of those structures in the creation of messages. The modular mind is a bio-social model of communication which presupposes a relationship between…

  8. Evolution and the Modularity of Mindreading.

    ERIC Educational Resources Information Center

    Moore, Chris

    1996-01-01

    Reviews Baron-Cohen's study of autism and an explanatory theory called modularity of mindreading, which proposed a domain-specific modular psychological model based on evolutionary, developmental, psychopathological, and neurobiological considerations. Enumerates problems with the modularity approach and emphasized the evolution of domain general…

  9. Modular Instruction Under Restricted Conditions.

    ERIC Educational Resources Information Center

    Utomo, Tjipto; Ruijter, Kees

    1984-01-01

    Describes the evaluation and reconstruction of a transport phenomena course given at the Bandung Institute of Technology which had a 70 percent failure rate. Discusses the teacher-paced modular instruction technique designed to replace the original course material and its results in terms of student performance over a three-year period. (JM)

  10. Rapidly Deployed Modular Telemetry System

    NASA Technical Reports Server (NTRS)

    Varnavas, Kosta A. (Inventor); Sims, William Herbert, III (Inventor)

    2013-01-01

    The present invention is a telemetry system, and more specifically is a rapidly deployed modular telemetry apparatus which utilizes of SDR technology and the FPGA programming capability to reduce the number of hardware components and programming required to deploy a telemetry system.

  11. Titanium by design: TRIP titanium alloy

    NASA Astrophysics Data System (ADS)

    Tran, Jamie

    Motivated by the prospect of lower cost Ti production processes, new directions in Ti alloy design were explored for naval and automotive applications. Building on the experience of the Steel Research Group at Northwestern University, an analogous design process was taken with titanium. As a new project, essential kinetic databases and models were developed for the design process and used to create a prototype design. Diffusion kinetic models were developed to predict the change in phase compositions and microstructure during heat treatment. Combining a mobility database created in this research with a licensed thermodynamic database, ThermoCalc and DICTRA software was used to model kinetic compositional changes in titanium alloys. Experimental diffusion couples were created and compared to DICTRA simulations to refine mobility parameters in the titanium mobility database. The software and database were able to predict homogenization times and the beta→alpha plate thickening kinetics during cooling in the near-alpha Ti5111 alloy. The results of these models were compared to LEAP microanalysis and found to be in reasonable agreement. Powder metallurgy was explored using SPS at GM R&D to reduce the cost of titanium alloys. Fully dense Ti5111 alloys were produced and achieved similar microstructures to wrought Ti5111. High levels of oxygen in these alloys increased the strength while reducing the ductility. Preliminary Ti5111+Y alloys were created, where yttrium additions successfully gettered excess oxygen to create oxides. However, undesirable large oxides formed, indicating more research is needed into the homogeneous distribution of the yttrium powder to create finer oxides. Principles established in steels were used to optimize the beta phase transformation stability for martensite transformation toughening in titanium alloys. The Olson-Cohen kinetic model is calibrated to shear strains in titanium. A frictional work database is established for common alloying

  12. Quasispecies theory for evolution of modularity

    NASA Astrophysics Data System (ADS)

    Park, Jeong-Man; Niestemski, Liang Ren; Deem, Michael W.

    2015-01-01

    Biological systems are modular, and this modularity evolves over time and in different environments. A number of observations have been made of increased modularity in biological systems under increased environmental pressure. We here develop a quasispecies theory for the dynamics of modularity in populations of these systems. We show how the steady-state fitness in a randomly changing environment can be computed. We derive a fluctuation dissipation relation for the rate of change of modularity and use it to derive a relationship between rate of environmental changes and rate of growth of modularity. We also find a principle of least action for the evolved modularity at steady state. Finally, we compare our predictions to simulations of protein evolution and find them to be consistent.

  13. Quasispecies Theory for Evolution of Modularity

    PubMed Central

    Park, Jeong-Man; Niestemski, Liang Ren; Deem, Michael W.

    2015-01-01

    Biological systems are modular, and this modularity evolves over time and in different environments. A number of observations have been made of increased modularity in biological systems under increased environmental pressure. We here develop a quasispecies theory for the dynamics of modularity in populations of these systems. We show how the steady-state fitness in a randomly changing environment can be computed. We derive a fluctuation dissipation relation for the rate of change of modularity and use it to derive a relationship between rate of environmental changes and rate of growth of modularity. We also find a principle of least action for the evolved modularity at steady state. Finally, we compare our predictions to simulations of protein evolution and find them to be consistent. PMID:25679649

  14. Quasispecies theory for evolution of modularity.

    PubMed

    Park, Jeong-Man; Niestemski, Liang Ren; Deem, Michael W

    2015-01-01

    Biological systems are modular, and this modularity evolves over time and in different environments. A number of observations have been made of increased modularity in biological systems under increased environmental pressure. We here develop a quasispecies theory for the dynamics of modularity in populations of these systems. We show how the steady-state fitness in a randomly changing environment can be computed. We derive a fluctuation dissipation relation for the rate of change of modularity and use it to derive a relationship between rate of environmental changes and rate of growth of modularity. We also find a principle of least action for the evolved modularity at steady state. Finally, we compare our predictions to simulations of protein evolution and find them to be consistent.

  15. Cuprate superconductors on titanium substrates

    NASA Astrophysics Data System (ADS)

    Mitterbauer, Christina; Gritzner, Gerhard

    2007-09-01

    The applicability of titanium as substrate material for coated conductors was investigated. Titanium metal was rolled to a thickness of 1 mm and mechanically polished. The titanium sheets were oxidized in air at 1000 °C for 1 h. A dense oxide layer was formed. YBCO superconducting layers were applied to the oxidized titanium surface via screen printing from a suspension in acetone-terpineol. The YBCO layers were characterized by X-ray diffraction and by scanning electron microscopy.

  16. Weld-bonded titanium structures

    NASA Technical Reports Server (NTRS)

    Vaughan, R. W.; Creedon, J. F. (Inventor)

    1976-01-01

    Structurally stronger titanium articles are produced by a weld-bonding technique comprising fastening at least two plates of titanium together using spotwelding and curing an adhesive interspersed between the spot-weld nuggets. This weld-bonding may be employed to form lap joints or to stiffen titanium metal plates.

  17. Titanium metal: extraction to application

    SciTech Connect

    Gambogi, Joseph; Gerdemann, Stephen J.

    2002-09-01

    In 1998, approximately 57,000 tons of titanium metal was consumed in the form of mill products (1). Only about 5% of the 4 million tons of titanium minerals consumed each year is used to produce titanium metal, with the remainder primarily used to produce titanium dioxide pigment. Titanium metal production is primarily based on the direct chlorination of rutile to produce titanium tetrachloride, which is then reduced to metal using the Kroll magnesium reduction process. The use of titanium is tied to its high strength-to-weight ratio and corrosion resistance. Aerospace is the largest application for titanium. In this paper, we discuss all aspects of the titanium industry from ore deposits through extraction to present and future applications. The methods of both primary (mining of ore, extraction, and purification) and secondary (forming and machining) operations will be analyzed. The chemical and physical properties of titanium metal will be briefly examined. Present and future applications for titanium will be discussed. Finally, the economics of titanium metal production also are analyzed as well as the advantages and disadvantages of various alternative extraction methods.

  18. Mineral of the month: titanium

    USGS Publications Warehouse

    Gambogi, Joseph

    2004-01-01

    From paint to airplanes, titanium is important in a number of applications. Commercial production comes from titanium-bearing ilmenite, rutile and leucoxene (altered ilmenite). These minerals are used to produce titanium dioxide pigment, as well as an assortment of metal and chemical products.

  19. Surface modification of titanium and titanium alloys by ion implantation.

    PubMed

    Rautray, Tapash R; Narayanan, R; Kwon, Tae-Yub; Kim, Kyo-Han

    2010-05-01

    Titanium and titanium alloys are widely used in biomedical devices and components, especially as hard tissue replacements as well as in cardiac and cardiovascular applications, because of their desirable properties, such as relatively low modulus, good fatigue strength, formability, machinability, corrosion resistance, and biocompatibility. However, titanium and its alloys cannot meet all of the clinical requirements. Therefore, to improve the biological, chemical, and mechanical properties, surface modification is often performed. In view of this, the current review casts new light on surface modification of titanium and titanium alloys by ion beam implantation.

  20. Tensile and creep properties of titanium-vanadium, titanium-molybdenum, and titanium-niobium alloys

    NASA Technical Reports Server (NTRS)

    Gray, H. R.

    1975-01-01

    Tensile and creep properties of experimental beta-titanium alloys were determined. Titanium-vanadium alloys had substantially greater tensile and creep strength than the titanium-niobium and titanium-molybdenum alloys tested. Specific tensile strengths of several titanium-vanadium-aluminum-silicon alloys were equivalent or superior to those of commercial titanium alloys to temperatures of 650 C. The Ti-50V-3Al-1Si alloy had the best balance of tensile strength, creep strength, and metallurgical stability. Its 500 C creep strength was far superior to that of a widely used commercial titanium alloy, Ti-6Al-4V, and almost equivalent to that of newly developed commercial titanium alloys.

  1. Modular Stellarator Fusion Reactor concept

    SciTech Connect

    Miller, R.L.; Krakowski, R.A.

    1981-08-01

    A preliminary conceptual study is made of the Modular Stellarator Reactor (MSR). A steady-state ignited, DT-fueled, magnetic fusion reactor is proposed for use as a central electric-power station. The MSR concept combines the physics of the classic stellarator confinement topology with an innovative, modular-coil design. Parametric tradeoff calculations are described, leading to the selection of an interim design point for a 4-GWt plant based on Alcator transport scaling and an average beta value of 0.04 in an l = 2 system with a plasma aspect ratio of 11. The physics basis of the design point is described together with supporting magnetics, coil-force, and stress computations. The approach and results presented herein will be modified in the course of ongoing work to form a firmer basis for a detailed conceptual design of the MSR.

  2. Relaxation labeling using modular operators

    SciTech Connect

    Duncan, J.S.; Frei, W.

    1983-01-01

    Probabilistic relaxation labeling has been shown to be useful in image processing, pattern recognition, and artificial intelligence. The approaches taken to date have been encumbered with computationally extensive summations which generally prevent real-time operation and/or easy hardware implementation. The authors present a new and unique approach to the relaxation labeling problem using modular, VLSI-oriented hierarchical complex operators. One of the fundamental concepts of this work is the representation of the probability distribution of the possible labels for a given object (pixel) as an ellipse, which may be summed with neighboring object's distribution ellipses, resulting in a new, relaxed label space. The mathematical development of the elliptical approach will be presented and compared to more classical approaches, and a hardware block diagram that shows the implementation of the relaxation scheme using vlsi chips will be presented. Finally, results will be shown which illustrate applications of the modular scheme, iteratively, to both edges and lines. 13 references.

  3. Modular hydrodam: concept definition study

    SciTech Connect

    Not Available

    1981-07-01

    The purpose of this investigation was to explore the potential for developing economical new ultra low-head (6 to 10 ft) sites using an innovative concept known as the Modular Hydrodam (MH). This concept combines the benefits of shop fabrication, installation of equipment in truck transportable, waterproof power modules, and prefabricated gate sections that can be located between the power modules. The size and weight of the power module permits it to be fully assembled and checked out in the manufacturer's shop. The module can then be broken down into four pieces and shipped by truck to the site. Once in place, concrete ballast will be added, as necessary, to prevent flotation. The following aspects were investigated: tubular and cross flow turbines; modularized components; the use of a cable support system for horizontal stability of the dam and powerhouse; and construction in the wet as well as in the dry.

  4. Tracing Titanium Escape

    NASA Image and Video Library

    2015-05-07

    The plot of data from NASA's Nuclear Spectroscopic Telescope Array, or NuSTAR (right), amounts to a "smoking gun" of evidence in the mystery of how massive stars explode. The observations indicate that supernovae belonging to a class called Type II or core-collapse blast apart in a lopsided fashion, with the core of the star hurtling in one direction, and the ejected material mostly expanding the other way (see diagram in Figure 1). NuSTAR made the most precise measurements yet of a radioactive element, called titanium-44, in the supernova remnant called 1987A. NuSTAR sees high-energy X-rays, as shown here in the plot ranging from 60 to more than 80 kiloelectron volts. The spectral signature of titanium-44 is apparent as the two tall peaks. The white line shows where one would expect to see these spectral signatures if the titanium were not moving. The fact that the spectral peaks have shifted to lower energies indicates that the titanium has "redshifted," and is moving way from us. This is similar to what happens to a train's whistle as the train leaves the station. The whistle's sound shifts to lower frequencies. NuSTAR's detection of redshifted titanium reveals that the bulk of material ejected in the 1987A supernova is flying way from us at a velocity of 1.6 million miles per hour (2.6 million kilometers per hour). Had the explosion been spherical in nature, the titanium would have been seen flying uniformly in all directions. This is proof that this explosion occurred in an asymmetrical fashion. http://photojournal.jpl.nasa.gov/catalog/PIA19335

  5. Modular Platforms for Optofluidic Systems

    NASA Astrophysics Data System (ADS)

    Brammer, Marko; Mappes, Timo

    2014-01-01

    Optofluidics is increasingly gaining impact in a number of different fields of research, namely biology and medicine, environmental monitoring and green energy. However, the market for optofluidic products is still in the early development phase. In this manuscript, we discuss modular platforms as a potential concept to facilitate the transfer of optofluidic sensing systems to an industrial implementation. We present microfluidic and optical networks as a basis for the interconnection of optofluidic sensor modules. Finally, we show the potential for entire optofluidic networks

  6. PTERA - Modular Aircraft Flight Test

    NASA Image and Video Library

    2016-01-13

    Aerospace testing can be costly and time consuming but a new modular, subscale remotely piloted aircraft offers NASA researchers more affordable options for developing a wide range of cutting edge aviation and space technologies. The Prototype-Technology Evaluation and Research Aircraft (PTERA), developed by Area-I, Inc., of Kennesaw, Georgia, is an extremely versatile and high quality, yet inexpensive, flying laboratory bridging the gap between wind tunnels and crewed flight testing.

  7. Modular Platforms for Optofluidic Systems

    NASA Astrophysics Data System (ADS)

    Brammer, Marko; Mappes, Timo

    2013-02-01

    Optofluidics is increasingly gaining impact in a number of different fields of research, namely biology and medicine, environmental monitoring and green energy. However, the market for optofluidic products is still in the early development phase. In this manuscript, we discuss modular platforms as a potential concept to facilitate the transfer of optofluidic sensing systems to an industrial implementation. We present microfluidic and optical networks as a basis for the interconnection of optofluidic sensor modules. Finally, we show the potential for entire optofluidic networks.

  8. Modular Platforms for Optofluidic Systems

    NASA Astrophysics Data System (ADS)

    Brammer, Marko; Mappes, Timo

    2014-01-01

    Optofluidics is increasingly gaining impact in a number of different fields of research, namely biology and medicine, environmental monitoring and green energy. However, the market for optofluidic products is still in the early development phase. In this manuscript, we discuss modular platforms as a potential concept to facilitate the transfer of optofluidic sensing systems to an industrial implementation. We present microfluidic and optical networks as a basis for the interconnection of optofluidic sensor modules. Finally, we show the potential for entire optofluidic networks

  9. Multidimensional bioseparation with modular microfluidics

    DOEpatents

    Chirica, Gabriela S.; Renzi, Ronald F.

    2013-08-27

    A multidimensional chemical separation and analysis system is described including a prototyping platform and modular microfluidic components capable of rapid and convenient assembly, alteration and disassembly of numerous candidate separation systems. Partial or total computer control of the separation system is possible. Single or multiple alternative processing trains can be tested, optimized and/or run in parallel. Examples related to the separation and analysis of human bodily fluids are given.

  10. CAMAC modular programmable function generator

    SciTech Connect

    Turner, G.W.; Suehiro, S.; Hendricks, R.W.

    1980-12-01

    A CAMAC modular programmable function generator has been developed. The device contains a 1024 word by 12-bit memory, a 12-bit digital-to-analog converter with a 600 ns settling time, an 18-bit programmable frequency register, and two programmable trigger output registers. The trigger registers can produce programmed output logic transitions at various (binary) points in the output function curve, and are used to synchronize various other data acquisition devices with the function curve.

  11. Estimation of inter-modular connectivity from the local field potentials in a hierarchical modular network

    NASA Astrophysics Data System (ADS)

    Cui, Xue-Mei; Kim, Won Sup; Hwang, Dong-Uk; Han, Seung Kee

    2015-05-01

    We propose a method of estimating inter-modular connectivity in a hierarchical modular network. The method is based on an analysis of inverse phase synchronization applied to the local field potentials on a hierarchical modular network of phase oscillators. For a strong-coupling strength, the inverse phase synchronization index of the local field potentials for two modules depends linearly on the corresponding inter-modular connectivity defined as the number of links connecting the modules. The method might enable us to estimate the inter-modular connectivity in various complex systems from the inverse phase synchronization index of the mesoscopic modular activities.

  12. Titanium alkoxide compound

    DOEpatents

    Boyle, Timothy J.

    2007-08-14

    A titanium alkoxide composition is provided, as represented by the chemical formula (OC.sub.6H.sub.5N).sub.2Ti(OC.sub.6H.sub.5NH.sub.2).sub.2. As prepared, the compound is a crystalline substance with a hexavalent titanium atom bonded to two OC.sub.6H.sub.5NH.sub.2 groups and two OC.sub.6H.sub.5N groups with a theoretical molecular weight of 480.38, comprising 60.01% C, 5.04% H and 11.66% N.

  13. Cyclic modular beta-sheets.

    PubMed

    Woods, R Jeremy; Brower, Justin O; Castellanos, Elena; Hashemzadeh, Mehrnoosh; Khakshoor, Omid; Russu, Wade A; Nowick, James S

    2007-03-07

    The development of peptide beta-hairpins is problematic, because folding depends on the amino acid sequence and changes to the sequence can significantly decrease folding. Robust beta-hairpins that can tolerate such changes are attractive tools for studying interactions involving protein beta-sheets and developing inhibitors of these interactions. This paper introduces a new class of peptide models of protein beta-sheets that addresses the problem of separating folding from the sequence. These model beta-sheets are macrocyclic peptides that fold in water to present a pentapeptide beta-strand along one edge; the other edge contains the tripeptide beta-strand mimic Hao [JACS 2000, 122, 7654] and two additional amino acids. The pentapeptide and Hao-containing peptide strands are connected by two delta-linked ornithine (deltaOrn) turns [JACS 2003, 125, 876]. Each deltaOrn turn contains a free alpha-amino group that permits the linking of individual modules to form divalent beta-sheets. These "cyclic modular beta-sheets" are synthesized by standard solid-phase peptide synthesis of a linear precursor followed by solution-phase cyclization. Eight cyclic modular beta-sheets 1a-1h containing sequences based on beta-amyloid and macrophage inflammatory protein 2 were synthesized and characterized by 1H NMR. Linked cyclic modular beta-sheet 2, which contains two modules of 1b, was also synthesized and characterized. 1H NMR studies show downfield alpha-proton chemical shifts, deltaOrn delta-proton magnetic anisotropy, and NOE cross-peaks that establish all compounds but 1c and 1g to be moderately or well folded into a conformation that resembles a beta-sheet. Pulsed-field gradient NMR diffusion experiments show little or no self-association at low (

  14. Modular microrobot for swimming in heterogeneous environments

    NASA Astrophysics Data System (ADS)

    Cheang, U. Kei; Meshkati, Meshkati; Fu, Henry; Kim, Minjun; Drexel University Team; University of Nevada, Reno Team

    2015-11-01

    One of the difficulties in navigating in vivo is to overcome many types of environments. This includes blood vessels of different diameters, fluids with different mechanical properties, and physical barriers. Inspired by conventional modular robotics, we demonstrate modular microrobotics using magnetic particles as the modular units to change size and shape through docking and undocking. Much like the vast variety of microorganisms navigating many different bio-environments, modular microswimmers have the ability to dynamically adapt different environments by reconfiguring the swimmers' physical characteristics. We model the docking as magnetic assembly and undocking mechanisms as deformation by hydrodynamic forces. We characterize the swimming capability of the modular microswimmer with different size and shapes. Finally, we demonstrate modular microrobotics by assembling a three-bead microswimmer into a nine-bead microswimmer, and then disassemble it into several independently swimming microswimmers..

  15. Modular Design in Treaty Verification Equipment

    SciTech Connect

    Macarthur, Duncan Whittemore; Benz, Jacob; Tolk, Keith; Weber, Tom

    2015-01-27

    It is widely believed that modular design is a good thing. However, there are often few explicit arguments, or even an agreed range of definitions, to back up this belief. In this paper, we examine the potential range of design modularity, the implications of various amounts of modularity, and the advantages and disadvantages of each level of modular construction. We conclude with a comparison of the advantages and disadvantages of each type, as well as discuss many caveats that should be observed to take advantage of the positive features of modularity and minimize the effects of the negative. The tradeoffs described in this paper will be evaluated during the conceptual design to determine what amount of modularity should be included.

  16. Modular workcells: modern methods for laboratory automation.

    PubMed

    Felder, R A

    1998-12-01

    Laboratory automation is beginning to become an indispensable survival tool for laboratories facing difficult market competition. However, estimates suggest that only 8% of laboratories will be able to afford total laboratory automation systems. Therefore, automation vendors have developed alternative hardware configurations called 'modular automation', to fit the smaller laboratory. Modular automation consists of consolidated analyzers, integrated analyzers, modular workcells, and pre- and post-analytical automation. These terms will be defined in this paper. Using a modular automation model, the automated core laboratory will become a site where laboratory data is evaluated by trained professionals to provide diagnostic information to practising physicians. Modem software information management and process control tools will complement modular hardware. Proper standardization that will allow vendor-independent modular configurations will assure success of this revolutionary new technology.

  17. Sintering titanium powders

    SciTech Connect

    Gerdemann, Stephen J.; Alman, David E.

    2005-09-01

    Recently, there has been renewed interest in low-cost titanium. Near-net-shape powder metallurgy offers the potential of manufacturing titanium articles without costly and difficult forming and machining operations; hence, processing methods such as conventional press-and-sinter, powder forging and powder injection molding are of interest. The sintering behavior of a variety of commercial and experimental titanium powders was studied. Commercial powders were acquired that were produced different routes: (i) sponge fines from the primary titanium processing; (ii) via the hydride-dehydride process; and (iii) gas atomization. The influence of vacuum sintering time (0.5 to 32 hrs) and temperature (1200, 1275 or 1350°C) on the microstructure (porosity present) of cold pressed powders was studied. The results are discussed in terms of the difference in powder characteristics, with the aim of identify the characteristics required for full density via press-and-sinter processing. Near-net-shape tensile bars were consolidated via cold pressed and sintered. After sintering, a sub-set of the tensile bars was hot-isostatic pressed (HIPed). The microstructure and properties of the bars were compared in the sintered and HIPed conditions.

  18. Sorting Titanium Welding Rods

    NASA Technical Reports Server (NTRS)

    Ross, W. D., Jr.; Brown, R. L.

    1985-01-01

    Three types of titanium welding wires identified by their resistance to current flow. Welding-wire tester quickly identifies unknown titaniumalloy wire by touching wire with test probe, and comparing meter response with standard response. Before touching wire, tip of test probe dipped into an electrolyte.

  19. Modular, Hierarchical Learning By Artificial Neural Networks

    NASA Technical Reports Server (NTRS)

    Baldi, Pierre F.; Toomarian, Nikzad

    1996-01-01

    Modular and hierarchical approach to supervised learning by artificial neural networks leads to neural networks more structured than neural networks in which all neurons fully interconnected. These networks utilize general feedforward flow of information and sparse recurrent connections to achieve dynamical effects. The modular organization, sparsity of modular units and connections, and fact that learning is much more circumscribed are all attractive features for designing neural-network hardware. Learning streamlined by imitating some aspects of biological neural networks.

  20. Modular, Hierarchical Learning By Artificial Neural Networks

    NASA Technical Reports Server (NTRS)

    Baldi, Pierre F.; Toomarian, Nikzad

    1996-01-01

    Modular and hierarchical approach to supervised learning by artificial neural networks leads to neural networks more structured than neural networks in which all neurons fully interconnected. These networks utilize general feedforward flow of information and sparse recurrent connections to achieve dynamical effects. The modular organization, sparsity of modular units and connections, and fact that learning is much more circumscribed are all attractive features for designing neural-network hardware. Learning streamlined by imitating some aspects of biological neural networks.

  1. Bioactive macroporous titanium surface layer on titanium substrate.

    PubMed

    Kim, H M; Kokubo, T; Fujibayashi, S; Nishiguchi, S; Nakamura, T

    2000-12-05

    A macroporous titanium surface layer is often formed on titanium and titanium alloy implants for morphological fixation of the implants to bone via bony ingrowth into the porous structure. The surface of titanium metal was recently shown to become highly bioactive by being subjected to 5.0 M-NaOH treatment at 60 degrees C for 24 h and subsequent heat treatment at 600 degrees C for 1 h. In the present study, the NaOH and heat treatments were applied to a macroporous titanium surface layer formed on titanium substrate by a plasma spraying method. The NaOH and heat treatments produced an uniform amorphous sodium titanate layer on the surface of the porous titanium. The sodium titanate induced a bonelike apatite formation in simulated body fluid at an early soaking period, whereby the apatite layer grew uniformly along the surface and cross-sectional macrotextures of the porous titanium. This indicates that the NaOH and heat treatments lead to a bioactive macroporous titanium surface layer on titanium substrate. Such a bioactive macroporous layer on an implant is expected not only to enhance bony ingrowth into the porous structure, but also to provide a chemical integration with bone via apatite formation on its surface in the body.

  2. Local bulk physics from intersecting modular Hamiltonians

    NASA Astrophysics Data System (ADS)

    Kabat, Daniel; Lifschytz, Gilad

    2017-06-01

    We show that bulk quantities localized on a minimal surface homologous to a boundary region correspond in the CFT to operators that commute with the modular Hamiltonian associated with the boundary region. If two such minimal surfaces intersect at a point in the bulk then CFT operators which commute with both extended modular Hamiltonians must be localized at the intersection point. We use this to construct local bulk operators purely from CFT considerations, without knowing the bulk metric, using intersecting modular Hamiltonians. For conformal field theories at zero and finite temperature the appropriate modular Hamiltonians are known explicitly and we recover known expressions for local bulk observables.

  3. Modular surface functionalization of polyisobutylene-based biomaterials

    NASA Astrophysics Data System (ADS)

    Alvarez Albarran, Alejandra

    Polyisobutylene (PIB) has a unique combination of properties including chemical/oxidative resistance, low Tg (˜70 °C) and hydrophobicity. 1 PIB-based materials have also been found to have excellent biocompatibility and biostability: a PIB-based triblock copolymer thermoplastic elastomer (TPE) [poly(styrene-b-isobutylene-b-styrene)] (SIBS) is FDA-approved as a drug eluting coating for coronary stents.2 A new generation of PIB-based TPEs, with an arborescent or tree-like core (arbPIB) and plastic phases composed of blocks of polystyrene or poly(p-methyl styrene) (MS) has been developed in Professor Puskas group. These materials display unique TPE properties to make them very attractive for biomedical applications.3 The biocompatibility of these novel block copolymers has already been demonstrated in vitro and in vivo in rabbits.4. The Puskas group proposed to modify the surface properties of PIB-based TPEs using a modular approach. Using this approach it is possible to modify the surface chemistry and topology independently. The surface chemistry can be modified by "gluing" low molecular weight functionalized PIBs (PIB-X) to the surface of the TPEs. This "modular" approach will give unprecedented control over surface chemistry and topology and will contribute to new fundamental understanding of the effects of surface properties on the biocompatibility of polymeric materials. In this work PIB with a primary hydroxy head group (HO-PIB) was made in situ by living carbocationic polymerization using propylene oxide as initiator and titanium tetrachloride (TiCl4 ) as coinitiator. PIB functionalized with non-fouling moieties (PIB-X) was then synthesized from HO-PIB using Candida antarctica Lipase B (CALB) as enzymatic catalyst and spin coated onto the surface of the TPE. Protein adsorption studies using Surface Plasmon Resonance (SPR) demonstrated decreased fibrinogen (Fg) adsorption to the modified surface. XPS analyses provided clear evidence of the effectiveness of

  4. [The Role of a Modular Universal Tumour and Revision System (MUTARS®) in Lower Limb Endoprosthetic Revision Surgery - Outcome Analysis of 25 Patients].

    PubMed

    Schmolders, J; Koob, S; Schepers, P; Gravius, S; Wirtz, D C; Burger, C; Pennekamp, P H; Strauss, A C

    2017-02-01

    Introduction/Background: With extended life expectancy, the number of primary joint arthroplasties has also increased. Revision surgery is also more often necessary, due to aseptic or septic loosening of the prosthesis or periprosthetic fracture. Large bone defects often occur in these patients and several non-modular, conventional implants are available to handle this difficult situation. Custom made implants offer an individually designed and defect-adapted shape with perfect covering of the lesion, but may delay the operation. The Modular Universal Tumor And Revision System (MUTARS®) offers the possibility to vary the length and angle of the femoral neck and the antetorsion angle. Thus, it permits intraoperative adaption to the individual patient's defect. The aim of our study is to present clinical, functional results and the rate of complications in a cohort of patients undergoing revision surgery for failed endoprosthetic replacement or failed trauma surgery, using the Modular Universal Tumor And Revision System with short-to midterm follow-up. Patients and Methods: Between August 2005 and September 2014, 25 patients (17 female, 8 male) with an average age of 72 years (min. 56, max. 92 years) were included in a retrospective study using the MUTARS® system. The patients underwent surgical revision of osseous defects that were not susceptible to conventional care. The mean follow-up was 16 months (min. 12, max. 72 months). The indications which led to revision surgery were as follows: loosened metal-on-metal prosthesis with an acetabular defect caused by a metal-induced granuloma (n = 1), pseudoarthrosis after implantation of femur nail (n = 2), cut-out of a femur nail (n = 1), aseptic loosening of an implanted endoprosthesis (n = 4), septic loosening of an implanted endoprosthesis (n = 1), periprosthetic fracture (n = 6) and periprosthetic infection after two stage revision surgery (infection consolidated Girdlestone situation) (n = 10). All patients were

  5. Modular passive solar heating system

    SciTech Connect

    Hunter, B.D.

    1985-03-19

    A modular passive solar energy storage system comprises a plurality of heat tubes which are arranged to form a flat plate solar collector and are releasably connected to a water reservoir by, and are part of, double-walled heat exchangers which penetrate to the water reservoir and enhance the heat transfer characteristics between the collector and the reservoir. The flat plate collector-heat exchanger disassembly, the collector housing, and the reservoir are integrated into a relatively light weight, unitary structural system in which the reservoir is a primary structural element. In addition to light weight, the system features high efficiency and ease of assembly and maintenance.

  6. Modular design attitude control system

    NASA Technical Reports Server (NTRS)

    Chichester, F. D.

    1984-01-01

    A sequence of single axismodels and a series of reduced state linear observers of minimum order are used to reconstruct inaccessible variables pertaining to the modular attitude control of a rigid body flexible suspension model of a flexible spacecraft. The single axis models consist of two, three, four, and five rigid bodies, each interconnected by a flexible shaft passing through the mass centers of the bodies. Modal damping is added to each model. Reduced state linear observers are developed for synthesizing the inaccessible modal state variables for each modal model.

  7. Modular design attitude control system

    NASA Technical Reports Server (NTRS)

    Chichester, F. D.

    1983-01-01

    Application of modular control techniques to the attitude control of a prototype flexible spacecraft and a prototype flexible space platform was further developed by determining numerical values for the physical parameters of a four body approximation of the MSFC/hybrid deployable truss incorporated in the space platform model, generating sensitivity coefficients for the model of the flexible spacecraft, evaluating the changes in the digital computer simulation of the flexible spacecraft resulting from the addition of another rigid body to the model and comparing attitude control effectiveness with actuators on more than one rigid body of the model with that for the case in which the actuators were restricted to one body.

  8. Cascading dynamics in modular networks

    NASA Astrophysics Data System (ADS)

    Galstyan, Aram; Cohen, Paul

    2007-03-01

    In this paper we study a simple cascading process in a structured heterogeneous population, namely, a network composed of two loosely coupled communities. We demonstrate that under certain conditions the cascading dynamics in such a network has a two-tiered structure that characterizes activity spreading at different rates in the communities. We study the dynamics of the model using both simulations and an analytical approach based on annealed approximation and obtain good agreement between the two. Our results suggest that network modularity might have implications in various applications, such as epidemiology and viral marketing.

  9. Integrated modular engine - Reliability assessment

    NASA Astrophysics Data System (ADS)

    Parsley, R. C.; Ward, T. B.

    1992-07-01

    A major driver in the increased interest in integrated modular engine configurations is the desire for ultra reliability for future rocket propulsion systems. The concept of configuring multiple sets of turbomachinery networked to multiple thrust chamber assemblies has been identified as an approach with potential to achieve significant reliability enhancement. This paper summarizes the results of a reliability study comparing networked systems vs. discrete engine installations, both with and without major module and engine redundancy. The study was conducted for gas generator, expander, and staged combustion cycles. The results are representative of either booster or upper-stage applications and are indicative of either plug or nonplug installation philosophies.

  10. Revised Modularity Index to Measure Modularity of OSS Projects with Case Study of Freemind

    NASA Astrophysics Data System (ADS)

    WahjuRahardjoEmanuel, Andi; Jahja Surjawan, Daniel

    2012-12-01

    Open Source Software (OSS) Projects are gaining popularity worldwide. Studies by many researchers show that the important key success factor is modularity of the source code. This paper presents the revised Modularity Index which is a software metrics to measure the modularity level of a javabased OSS Projects. To show its effectiveness in analyzing OSS Project, the Modularity Index and its supporting software metrics are then used to analyze the evolution of Freemind mind mapping OSS Project. The analysis using Modularity Index and its supporting metrics shows the strength and weaknesses of the Freemind OSS Projects.

  11. The Iterative Structure Analysis of Montgomery Modular Multiplication

    NASA Astrophysics Data System (ADS)

    Jinbo, Wang

    2007-09-01

    Montgomery modular multiplication (MMM) plays a crucial role in the implementation of modular exponentiations of public-key cryptography. In this paper, we discuss the iterative structure and extend the iterative bound condition of MMM. It can be applied to complicated modular exponentiations. Based on the iterative condition of MMM, we can directly use non-modular additions, subtractions and even simple multiplications instead of the modular forms, which make modular exponentiation operation very efficient but more importantly iterative applicability of MMM.

  12. Decentralized and Modular Electrical Architecture

    NASA Astrophysics Data System (ADS)

    Elisabelar, Christian; Lebaratoux, Laurence

    2014-08-01

    This paper presents the studies made on the definition and design of a decentralized and modular electrical architecture that can be used for power distribution, active thermal control (ATC), standard inputs-outputs electrical interfaces.Traditionally implemented inside central unit like OBC or RTU, these interfaces can be dispatched in the satellite by using MicroRTU.CNES propose a similar approach of MicroRTU. The system is based on a bus called BRIO (Bus Réparti des IO), which is composed, by a power bus and a RS485 digital bus. BRIO architecture is made with several miniature terminals called BTCU (BRIO Terminal Control Unit) distributed in the spacecraft.The challenge was to design and develop the BTCU with very little volume, low consumption and low cost. The standard BTCU models are developed and qualified with a configuration dedicated to ATC, while the first flight model will fly on MICROSCOPE for PYRO actuations and analogue acquisitions. The design of the BTCU is made in order to be easily adaptable for all type of electric interface needs.Extension of this concept is envisaged for power conditioning and distribution unit, and a Modular PCDU based on BRIO concept is proposed.

  13. Compact stellarators with modular coils.

    PubMed

    Garabedian, P R

    2000-07-18

    Compact stellarator designs with modular coils and only two or three field periods are now available; these designs have both good stability and quasiaxial symmetry providing adequate transport for a magnetic fusion reactor. If the bootstrap current assumes theoretically predicted values a three field period configuration is optimal, but if that net current turns out to be lower, a device with two periods and just 12 modular coils might be better. There are also attractive designs with quasihelical symmetry and four or five periods whose properties depend less on the bootstrap current. Good performance requires that there be a satisfactory magnetic well in the vacuum field, which is a property lacking in a stellarator-tokamak hybrid that has been proposed for a proof of principle experiment. In this paper, we present an analysis of stability for these configurations that is based on a mountain pass theorem asserting that, if two solutions of the problem of magnetohydrodynamic equilibrium can be found, then there has to be an unstable solution. We compare results of our theory of equilibrium, stability, and transport with recently announced measurements from the large LHD experiment in Japan.

  14. Compact stellarators with modular coils

    PubMed Central

    Garabedian, P. R.

    2000-01-01

    Compact stellarator designs with modular coils and only two or three field periods are now available; these designs have both good stability and quasiaxial symmetry providing adequate transport for a magnetic fusion reactor. If the bootstrap current assumes theoretically predicted values a three field period configuration is optimal, but if that net current turns out to be lower, a device with two periods and just 12 modular coils might be better. There are also attractive designs with quasihelical symmetry and four or five periods whose properties depend less on the bootstrap current. Good performance requires that there be a satisfactory magnetic well in the vacuum field, which is a property lacking in a stellarator-tokamak hybrid that has been proposed for a proof of principle experiment. In this paper, we present an analysis of stability for these configurations that is based on a mountain pass theorem asserting that, if two solutions of the problem of magnetohydrodynamic equilibrium can be found, then there has to be an unstable solution. We compare results of our theory of equilibrium, stability, and transport with recently announced measurements from the large LHD experiment in Japan. PMID:10899993

  15. A modular BLSS simulation model

    NASA Technical Reports Server (NTRS)

    Rummel, John D.; Volk, Tyler

    1987-01-01

    A bioregenerative life support system (BLSS) for extraterrestrial use will be faced with coordination problems more acute than those in any ecosystem found on Earth. A related problem in BLSS design is providing an interface between the various life support processors, one that will allow for their coordination while still allowing for system expansion. A modular model is presented of a BLSS that interfaces system processors only with the material storage reservoirs, allowing those reservoirs to act as the principal buffers in the system and thus minimizing difficulties with processor coordination. The modular nature of the model allows independent development of the detailed submodels that exist within the model framework. Using this model, BLSS dynamics were investigated under normal conditions and under various failure modes. Partial and complete failures of various components, such as the waste processors or the plants themselves, drive transient responses in the model system, allowing the examination of the effectiveness of the system reservoirs as buffers. The results from simulations help to determine control strategies and BLSS design requirements. An evolved version could be used as an interactive control aid in a future BLSS.

  16. Learning modular policies for robotics.

    PubMed

    Neumann, Gerhard; Daniel, Christian; Paraschos, Alexandros; Kupcsik, Andras; Peters, Jan

    2014-01-01

    A promising idea for scaling robot learning to more complex tasks is to use elemental behaviors as building blocks to compose more complex behavior. Ideally, such building blocks are used in combination with a learning algorithm that is able to learn to select, adapt, sequence and co-activate the building blocks. While there has been a lot of work on approaches that support one of these requirements, no learning algorithm exists that unifies all these properties in one framework. In this paper we present our work on a unified approach for learning such a modular control architecture. We introduce new policy search algorithms that are based on information-theoretic principles and are able to learn to select, adapt and sequence the building blocks. Furthermore, we developed a new representation for the individual building block that supports co-activation and principled ways for adapting the movement. Finally, we summarize our experiments for learning modular control architectures in simulation and with real robots.

  17. Learning modular policies for robotics

    PubMed Central

    Neumann, Gerhard; Daniel, Christian; Paraschos, Alexandros; Kupcsik, Andras; Peters, Jan

    2014-01-01

    A promising idea for scaling robot learning to more complex tasks is to use elemental behaviors as building blocks to compose more complex behavior. Ideally, such building blocks are used in combination with a learning algorithm that is able to learn to select, adapt, sequence and co-activate the building blocks. While there has been a lot of work on approaches that support one of these requirements, no learning algorithm exists that unifies all these properties in one framework. In this paper we present our work on a unified approach for learning such a modular control architecture. We introduce new policy search algorithms that are based on information-theoretic principles and are able to learn to select, adapt and sequence the building blocks. Furthermore, we developed a new representation for the individual building block that supports co-activation and principled ways for adapting the movement. Finally, we summarize our experiments for learning modular control architectures in simulation and with real robots. PMID:24966830

  18. Modularity, noise, and natural selection.

    PubMed

    Marroig, Gabriel; Melo, Diogo A R; Garcia, Guilherme

    2012-05-01

    Most biological systems are formed by component parts that are to some degree interrelated. Groups of parts that are more associated among themselves and are relatively autonomous from others are called modules. One of the consequences of modularity is that biological systems usually present an unequal distribution of the genetic variation among traits. Estimating the covariance matrix that describes these systems is a difficult problem due to a number of factors such as poor sample sizes and measurement errors. We show that this problem will be exacerbated whenever matrix inversion is required, as in directional selection reconstruction analysis. We explore the consequences of varying degrees of modularity and signal-to-noise ratio on selection reconstruction. We then present and test the efficiency of available methods for controlling noise in matrix estimates. In our simulations, controlling matrices for noise vastly improves the reconstruction of selection gradients. We also perform an analysis of selection gradients reconstruction over a New World Monkeys skull database to illustrate the impact of noise on such analyses. Noise-controlled estimates render far more plausible interpretations that are in full agreement with previous results. © 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.

  19. A modular approach toward extremely large apertures

    NASA Astrophysics Data System (ADS)

    Woods, A. A., Jr.

    1981-02-01

    Modular antenna construction can provide a significant increase in reflector aperture size over deployable reflectors. The modular approach allows reflective mesh surfaces to be supported by a minimum of structure. The kinematics of the selected deployable design approach were validated by the subscale demonstration model. Further design refinements on the module structural/joints and design optimization on intermodule joints are needed.

  20. Deployable modular mesh antenna - Concept and feasibility

    NASA Astrophysics Data System (ADS)

    Mitsugi, Jin; Yasaka, Tetsuo

    The feasibility of a 10m aperture deployable modular mesh antenna is evaluated by integrating the results of a statistical surface accuracy estimation and of surface shape adjustment experiments. It has been clarified that by combining seven 4m aperture modules, a 10m aperture deployable modular mesh antenna can be constructed, preserving the surface accuracy that is applicable to C band mission.

  1. Modular Building Institute 2000 Educational Showcase.

    ERIC Educational Resources Information Center

    Modular Building Inst., Charlottesville, VA.

    This publication contains brief articles concerned with modular school structures. The articles offer examples of such structures at actual schools. The articles in this issue are: (1) "Elementary K-8 Modular Courtyard"; (2) "School District #33, Chilliwack, BC"; (3) "New Elementary School for Briarwood, NY"; (4) "Addition to Queens Intermediate…

  2. Modular Buildings Are Here To Stay.

    ERIC Educational Resources Information Center

    Williams, Steven; Roman, Michael I.; Tiernan, Maury; Savage, Chuck; Airikka, Robert; Brosius, Jerry L.

    2000-01-01

    Presents several examples of modular building construction being used be school districts to support their need for more space, building flexibility, and enhancement of the learning environment. Comparisons with traditionally built school facilities are offered as are answers to commonly held myths concerning modular construction. (GR)

  3. Modular Construction: The Wave of the Future.

    ERIC Educational Resources Information Center

    Savage, Chuck

    1989-01-01

    Modular construction of school buildings offers speed of construction, with 100 percent contractor responsibility for the completed structures. Under negotiated terms, modular projects can be purchased outright or through long-term leasing arrangements that provide ownership at the end of the lease period. (MLF)

  4. Detectability thresholds of general modular graphs

    NASA Astrophysics Data System (ADS)

    Kawamoto, Tatsuro; Kabashima, Yoshiyuki

    2017-01-01

    We investigate the detectability thresholds of various modular structures in the stochastic block model. Our analysis reveals how the detectability threshold is related to the details of the modular pattern, including the hierarchy of the clusters. We show that certain planted structures are impossible to infer regardless of their fuzziness.

  5. 48 CFR 39.103 - Modular contracting.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 1 2013-10-01 2013-10-01 false Modular contracting. 39.103 Section 39.103 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION SPECIAL... extent practicable, use modular contracting to acquire major systems (see 2.101) of...

  6. 48 CFR 39.103 - Modular contracting.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Modular contracting. 39.103 Section 39.103 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION SPECIAL... extent practicable, use modular contracting to acquire major systems (see 2.101) of...

  7. A Modular Laser Graphics Projection System

    NASA Astrophysics Data System (ADS)

    Newswanger, Craig D.

    1984-05-01

    WED Enterprises has designed and built a modular projection system for the presentation of animated laser shows. This system was designed specifically for use in Disney theme shows. Its modular design allows it to be adapted to many show situations with simple hardware and software adjustments. The primary goals were superior animation, long life, low maintenance and stand alone operation.

  8. The relative efficiency of modular and non-modular networks of different size

    PubMed Central

    Tosh, Colin R.; McNally, Luke

    2015-01-01

    Most biological networks are modular but previous work with small model networks has indicated that modularity does not necessarily lead to increased functional efficiency. Most biological networks are large, however, and here we examine the relative functional efficiency of modular and non-modular neural networks at a range of sizes. We conduct a detailed analysis of efficiency in networks of two size classes: ‘small’ and ‘large’, and a less detailed analysis across a range of network sizes. The former analysis reveals that while the modular network is less efficient than one of the two non-modular networks considered when networks are small, it is usually equally or more efficient than both non-modular networks when networks are large. The latter analysis shows that in networks of small to intermediate size, modular networks are much more efficient that non-modular networks of the same (low) connective density. If connective density must be kept low to reduce energy needs for example, this could promote modularity. We have shown how relative functionality/performance scales with network size, but the precise nature of evolutionary relationship between network size and prevalence of modularity will depend on the costs of connectivity. PMID:25631996

  9. What sports activity levels are achieved in patients with modular tumor endoprostheses of osteosarcoma about the knee?

    PubMed

    Lang, Nikolaus W; Hobusch, Gerhard M; Funovics, Philipp T; Windhager, Reinhard; Hofstaetter, Jochen G

    2015-03-01

    Advances in multimodal treatment have improved survival of patients with nonmetastatic osteosarcoma. At the same time, implant design has improved the outcomes of limb salvage with modular endoprostheses. However, little is known about sports activity in long-term survivors with osteosarcoma. We wanted to evaluate (1) sports activity levels in long-term survivors of osteosarcoma about the knee who received a modular tumor endoprosthesis; (2) to determine if activity level changed over time from initial reconstruction or (3) was predicted from sports activity level before diagnosis; and (4) if complications that occurred affected sports or contributed to prosthetic failures. Between 1995 and 2005, we treated 120 patients for osteosarcoma about the knee with resection and modular endoprosthetic reconstruction; of those, 25 (21%) have died, six (5%) had an amputation, 39 (32%) did not speak German and so were ineligible, and 14 (12%) were either lost to followup or refused to participate, leaving 27 patients (14 females, 13 males; median age 19 years [range, 12-60 years); average followup 11 ± 4 years) (54% of the living, German-speaking cohort) for this analysis. Tumors were located in the distal femur (n = 16) and the proximal tibia (n = 11). Sports participation as well as the UCLA Activity Score and the modified Weighted Activity Score were assessed retrospectively. Moreover, postoperative complications were evaluated. Before the diagnosis of osteosarcoma and 1, 3, and 5 years and at the latest followup, respectively, after their reconstructions, 24 (89%), nine (33%), 20 (74%), and 24 patients (89%) were able to perform sports activities. There was a reduction in high-impact activities. Those patients with followup longer than 5 years had no changes in sports activity at their latest followup. Patients who had higher levels of sports activity levels before surgery generally had higher levels of activity at last followup (UCLA Activity Score: r = 0.62, p < 0

  10. Titanium Honeycomb Panel Testing

    NASA Technical Reports Server (NTRS)

    Richards, W. Lance; Thompson, Randolph C.

    1996-01-01

    Thermal-mechanical tests were performed on a titanium honeycomb sandwich panel to experimentally validate the hypersonic wing panel concept and compare test data with analysis. Details of the test article, test fixture development, instrumentation, and test results are presented. After extensive testing to 900 deg. F, non-destructive evaluation of the panel has not detected any significant structural degradation caused by the applied thermal-mechanical loads.

  11. Modularity maximization using completely positive programming

    NASA Astrophysics Data System (ADS)

    Yazdanparast, Sakineh; Havens, Timothy C.

    2017-04-01

    Community detection is one of the most prominent problems of social network analysis. In this paper, a novel method for Modularity Maximization (MM) for community detection is presented which exploits the Alternating Direction Augmented Lagrangian (ADAL) method for maximizing a generalized form of Newman's modularity function. We first transform Newman's modularity function into a quadratic program and then use Completely Positive Programming (CPP) to map the quadratic program to a linear program, which provides the globally optimal maximum modularity partition. In order to solve the proposed CPP problem, a closed form solution using the ADAL merged with a rank minimization approach is proposed. The performance of the proposed method is evaluated on several real-world data sets used for benchmarks community detection. Simulation results shows the proposed technique provides outstanding results in terms of modularity value for crisp partitions.

  12. Finding network communities using modularity density

    NASA Astrophysics Data System (ADS)

    Botta, Federico; del Genio, Charo I.

    2016-12-01

    Many real-world complex networks exhibit a community structure, in which the modules correspond to actual functional units. Identifying these communities is a key challenge for scientists. A common approach is to search for the network partition that maximizes a quality function. Here, we present a detailed analysis of a recently proposed function, namely modularity density. We show that it does not incur in the drawbacks suffered by traditional modularity, and that it can identify networks without ground-truth community structure, deriving its analytical dependence on link density in generic random graphs. In addition, we show that modularity density allows an easy comparison between networks of different sizes, and we also present some limitations that methods based on modularity density may suffer from. Finally, we introduce an efficient, quadratic community detection algorithm based on modularity density maximization, validating its accuracy against theoretical predictions and on a set of benchmark networks.

  13. The emergence of modularity in biological systems

    NASA Astrophysics Data System (ADS)

    Lorenz, Dirk M.; Jeng, Alice; Deem, Michael W.

    2011-06-01

    In this review, we discuss modularity and hierarchy in biological systems. We review examples from protein structure, genetics, and biological networks of modular partitioning of the geometry of biological space. We review theories to explain modular organization of biology, with a focus on explaining how biology may spontaneously organize to a structured form. That is, we seek to explain how biology nucleated from among the many possibilities in chemistry. The emergence of modular organization of biological structure will be described as a symmetry-breaking phase transition, with modularity as the order parameter. Experimental support for this description will be reviewed. Examples will be presented from pathogen structure, metabolic networks, gene networks, and protein-protein interaction networks. Additional examples will be presented from ecological food networks, developmental pathways, physiology, and social networks.

  14. Titanium: light, strong, and white

    USGS Publications Warehouse

    Woodruff, Laurel; Bedinger, George

    2013-01-01

    Titanium (Ti) is a strong silver-gray metal that is highly resistant to corrosion and is chemically inert. It is as strong as steel but 45 percent lighter, and it is twice as strong as aluminum but only 60 percent heavier. Titanium dioxide (TiO2) has a very high refractive index, which means that it has high light-scattering ability. As a result, TiO2 imparts whiteness, opacity, and brightness to many products. ...Because of the unique physical properties of titanium metal and the whiteness provided by TiO2, titanium is now used widely in modern industrial societies.

  15. Titanium fasteners. [for aircraft industry

    NASA Technical Reports Server (NTRS)

    Phillips, J. L.

    1972-01-01

    Titanium fasteners are used in large quantities throughout the aircraft industry. Most of this usage is in aluminum structure; where titanium structure exists, titanium fasteners are logically used as well. Titanium fasteners offer potential weight savings to the designer at a cost of approximately $30 per pound of weight saved. Proper and least cost usage must take into consideration type of fastener per application, galvanic couples and installation characteristics of protective coatings, cosmetic appearance, paint adhesion, installation forces and methods available and fatigue performance required.

  16. Small Modular Reactors: Institutional Assessment

    SciTech Connect

    Joseph Perkowski, Ph.D.

    2012-06-01

    ? Objectives include, among others, a description of the basic development status of “small modular reactors” (SMRs) focused primarily on domestic activity; investigation of the domestic market appeal of modular reactors from the viewpoints of both key energy sector customers and also key stakeholders in the financial community; and consideration of how to proceed further with a pro-active "core group" of stakeholders substantially interested in modular nuclear deployment in order to provide the basis to expedite design/construction activity and regulatory approval. ? Information gathering was via available resources, both published and personal communications with key individual stakeholders; published information is limited to that already in public domain (no confidentiality); viewpoints from interviews are incorporated within. Discussions at both government-hosted and private-hosted SMR meetings are reflected herein. INL itself maintains a neutral view on all issues described. Note: as per prior discussion between INL and CAP, individual and highly knowledgeable senior-level stakeholders provided the bulk of insights herein, and the results of those interviews are the main source of the observations of this report. ? Attachment A is the list of individual stakeholders consulted to date, including some who provided significant earlier assessments of SMR institutional feasibility. ? Attachments B, C, and D are included to provide substantial context on the international status of SMR development; they are not intended to be comprehensive and are individualized due to the separate nature of the source materials. Attachment E is a summary of the DOE requirements for winning teams regarding the current SMR solicitation. Attachment F deserves separate consideration due to the relative maturity of the SMART SMR program underway in Korea. Attachment G provides illustrative SMR design features and is intended for background. Attachment H is included for overview

  17. Processing of titanium and titanium alloys by thermal spraying

    SciTech Connect

    Lugscheider, E.; Jokiel, P.

    1994-12-31

    Marine environments are generally known as aggressive corrosion atmospheres. Stainless steel applied as corrosion resistant material is very effective, but it is also an expensive solution since very often only localized areas may need protection. So, protective coatings such as aluminum, zinc, titanium or Cu/Ni alloys, organic paints and epoxies have been used to provide sufficient protection. Especially titanium and titanium alloys offer a high chemical resistance against various corrosive media due to a dense self healing oxide layer. Besides corrosion resistance, high mechanical strength combined with low specific weight are further advantages of titanium alloys. Economical restrictions still hinder titanium to be used as construction material outside of special applications in aircraft and medical technology. Generally most applications only deserve a thin protective coating. Thermal spray processes allow to combine cheap structural materials with a thin layer of high value material. The high affinity of titanium to oxygen has to be taken into account spraying this material. Therefore plasma spraying can be performed in vacuum or in inert atmosphere as well as using gas shrouds in order to shield the molten particles from reacting with the surrounding environment. This paper gives an overview on thermal spraying of titanium and titanium alloys. Coating formation as well as its characterization with regard to corrosion resistance and mechanical strength is examined.

  18. Titanium Optics for Ion Thrusters

    NASA Technical Reports Server (NTRS)

    Soulas, George C.; Haag, Thomas W.; Patterson, Michael J.; Rawlin, Vincent K.

    1999-01-01

    Ion thruster total impulse capability is limited, in part, by accelerator grid sputter erosion. A development effort was initiated to identify a material with a lower accelerator grid volumetric sputter erosion rate than molybdenum, but that could utilize the present NSTAR thruster grid design and fabrication techniques to keep development costs low, and perform as well as molybdenum optics. After comparing the sputter erosion rates of several atomic materials to that of molybdenum at accelerator voltages, titanium was found to offer a 45% reduction in volumetric erosion rates. To ensure that screen grid sputter erosion rates are not higher at discharge chamber potentials, titanium and molybdenum sputter erosion rates were measured at these potentials. Preliminary results showed only a slightly higher volumetric erosion rate for titanium, so that screen grid erosion is insignificant. A number of material, thermal, and mechanical properties were also examined to identify any fabrication, launch environment, and thruster operation issues. Several titanium grid sets were successfully fabricated. A titanium grid set was mounted onto an NSTAR 30 cm engineering model ion thruster and tested to determine optics performance. The titanium optics operated successfully over the entire NSTAR power range of 0.5 to 2.3 kW. Differences in impingement-limited perveances and electron backstreaming limits were found to be due to a larger cold gap for the titanium optics. Discharge losses for titanium grids were lower than those for molybdenum, likely due to a slightly larger titanium screen grid open area fraction. Radial distributions of beam current density with titanium optics were very similar to those with molybdenum optics at all power levels. Temporal electron backstreaming limit measurements showed that titanium optics achieved thermal equilibrium faster than molybdenum optics.

  19. A bioinspired modular aquatic robot

    NASA Astrophysics Data System (ADS)

    Tallapragada, Phanindra; Pollard, Beau

    2016-11-01

    Several bio inspired swimming robots exist which seek to emulate the morphology of fish and the flapping motion of the tail and fins or other appendages and body of aquatic creatures. The locomotion of such robots and the aquatic animals that they seek to emulate is determined to a large degree by the changes in the shape of the body, which produce periodic changes in the momentum of the body and the creation and interaction of the vorticity field in the fluid with the body. We demonstrate an underactuated robot which swims due to the periodic changes in the angular momentum of the robot effected by the motion of an internal rotor. The robot is modular, unactuated tail like segments can be easily added to the robot. These segments modulate the interaction of the body with the fluid to produce a variety of passive shape changes that can allow the robot to swim in different modes.

  20. Analytical Spectroscopy Using Modular Systems

    NASA Astrophysics Data System (ADS)

    Patterson, Brian M.; Danielson, Neil D.; Lorigan, Gary A.; Sommer, André J.

    2003-12-01

    This article describes the development of three analytical spectroscopy experiments that compare the determination of salicylic acid (SA) content in aspirin tablets. The experiments are based on UV vis, fluorescence, and Raman spectroscopies and utilize modular spectroscopic components. Students assemble their own instruments, optimize them with respect to signal-to-noise, generate calibration curves, determine the SA content in retail aspirin tablets, and assign features in the respective spectra to functional groups within the active material. Using this approach in the discovery-based setting, the students gain invaluable insight into method-specific parameters, such as instrumental components, sample preparation, and analytical capability. In addition, the students learn the fundamentals of fiber optics and signal processing using the low-cost CCD based spectroscopic components.

  1. BESST: A Miniature, Modular Radiometer

    NASA Technical Reports Server (NTRS)

    Warden, Robert; Good, William; Baldwin-Stevens, Erik

    2010-01-01

    A new radiometer assembly has been developed that incorporates modular design principles in order to provide flexibility and versatility. The assembly, shown in Figure 1, is made up of six modules plus a central cubical frame. A small thermal imaging detector is used to determine the temperature of remote objects. To improve the accuracy of the temperature reading, frequent calibration is required. The detector must view known temperature targets before viewing the remote object. Calibration is achieved by using a motorized fold mirror to select the desired scene the detector views. The motor steps the fold mirror through several positions, which allows the detector to view the calibration targets or the remote object. The details, features, and benefits of the radiometer are described in this paper.

  2. MODULAR MANIPULATOR FOR ROBOTICS APPLICATIONS

    SciTech Connect

    Joseph W. Geisinger, Ph.D.

    2001-07-31

    ARM Automation, Inc. is developing a framework of modular actuators that can address the DOE's wide range of robotics needs. The objective of this effort is to demonstrate the effectiveness of this technology by constructing a manipulator from these actuators within a glovebox for Automated Plutonium Processing (APP). At the end of the project, the system of actuators was used to construct several different manipulator configurations, which accommodate common glovebox tasks such as repackaging. The modular nature and quickconnects of this system simplify installation into ''hot'' boxes and any potential modifications or repair therein. This work focused on the development of self-contained robotic actuator modules including the embedded electronic controls for the purpose of building a manipulator system. Both of the actuators developed under this project contain the control electronics, sensors, motor, gear train, wiring, system communications and mechanical interfaces of a complete robotics servo device. Test actuators and accompanying DISC{trademark}s underwent validation testing at The University of Texas at Austin and ARM Automation, Inc. following final design and fabrication. The system also included custom links, an umbilical cord, an open architecture PC-based system controller, and operational software that permitted integration into a completely functional robotic manipulator system. The open architecture on which this system is based avoids proprietary interfaces and communication protocols which only serve to limit the capabilities and flexibility of automation equipment. The system was integrated and tested in the contractor's facility for intended performance and operations. The manipulator was tested using the full-scale equipment and process mock-ups. The project produced a practical and operational system including a quantitative evaluation of its performance and cost.

  3. Osmotrophy in modular Ediacara organisms

    PubMed Central

    Laflamme, Marc; Xiao, Shuhai; Kowalewski, Michał

    2009-01-01

    The Ediacara biota include macroscopic, morphologically complex soft-bodied organisms that appear globally in the late Ediacaran Period (575–542 Ma). The physiology, feeding strategies, and functional morphology of the modular Ediacara organisms (rangeomorphs and erniettomorphs) remain debated but are critical for understanding their ecology and phylogeny. Their modular construction triggered numerous hypotheses concerning their likely feeding strategies, ranging from micro-to-macrophagus feeding to photoautotrophy to osmotrophy. Macrophagus feeding in rangeomorphs and erniettomorphs is inconsistent with their lack of oral openings, and photoautotrophy in rangeomorphs is contradicted by their habitats below the photic zone. Here, we combine theoretical models and empirical data to evaluate the feasibility of osmotrophy, which requires high surface area to volume (SA/V) ratios, as a primary feeding strategy of rangeomorphs and erniettomorphs. Although exclusively osmotrophic feeding in modern ecosystems is restricted to microscopic bacteria, this study suggests that (i) fractal branching of rangeomorph modules resulted in SA/V ratios comparable to those observed in modern osmotrophic bacteria, and (ii) rangeomorphs, and particularly erniettomorphs, could have achieved osmotrophic SA/V ratios similar to bacteria, provided their bodies included metabolically inert material. Thus, specific morphological adaptations observed in rangeomorphs and erniettomorphs may have represented strategies for overcoming physiological constraints that typically make osmotrophy prohibitive for macroscopic life forms. These results support the viability of osmotrophic feeding in rangeomorphs and erniettomorphs, help explain their taphonomic peculiarities, and point to the possible importance of earliest macroorganisms for cycling dissolved organic carbon that may have been present in abundance during Ediacaran times. PMID:19706530

  4. Size reduction of complex networks preserving modularity

    NASA Astrophysics Data System (ADS)

    Arenas, A.; Duch, J.; Fernández, A.; Gómez, S.

    2007-06-01

    The ubiquity of modular structure in real-world complex networks is the focus of attention in many trials to understand the interplay between network topology and functionality. The best approaches to the identification of modular structure are based on the optimization of a quality function known as modularity. However this optimization is a hard task provided that the computational complexity of the problem is in the non-deterministic polynomial-time hard (NP-hard) class. Here we propose an exact method for reducing the size of weighted (directed and undirected) complex networks while maintaining their modularity. This size reduction allows use of heuristic algorithms that optimize modularity for a better exploration of the modularity landscape. We compare the modularity obtained in several real complex-networks by using the extremal optimization algorithm, before and after the size reduction, showing the improvement obtained. We speculate that the proposed analytical size reduction could be extended to an exact coarse graining of the network in the scope of real-space renormalization.

  5. A Prototype for Modular Cell Engineering.

    PubMed

    Wilbanks, Brandon; Layton, Donovan; Garcia, Sergio; Trinh, Cong

    2017-10-10

    When aiming to produce a target chemical at high yield, titer, and productivity, various combinations of genetic parts available to build the target pathway can generate a large number of strains for characterization. This engineering approach will become increasingly laborious and expensive when seeking to develop desirable strains for optimal production of a large space of biochemicals due to extensive screening. Our recent theoretical development of modular cell (MODCELL) design principles can offer a promising solution for rapid generation of optimal strains by coupling a modular cell and exchangeable production modules in a plug-and-play fashion. In this study, we experimentally validated some designed properties of MODCELL by demonstrating: i) a modular (chassis) cell is required to couple with a production module, a heterologous ethanol pathway, as a testbed, ii) degree of coupling between the modular cell and production modules can be modulated to enhance growth and product synthesis, iii) a modular cell can be used as a host to select an optimal pyruvate decarboxylase (PDC) of the ethanol production module and to help identify a hypothetical PDC protein, and iv) adaptive laboratory evolution based on growth selection of the modular cell can enhance growth and product synthesis rates. We envision that the MODCELL design provides a powerful prototype for modular cell engineering to rapidly create optimal strains for synthesis of a large space of biochemicals.

  6. Size reduction of complex networks preserving modularity

    SciTech Connect

    Arenas, A.; Duch, J.; Fernandez, A.; Gomez, S.

    2008-12-24

    The ubiquity of modular structure in real-world complex networks is being the focus of attention in many trials to understand the interplay between network topology and functionality. The best approaches to the identification of modular structure are based on the optimization of a quality function known as modularity. However this optimization is a hard task provided that the computational complexity of the problem is in the NP-hard class. Here we propose an exact method for reducing the size of weighted (directed and undirected) complex networks while maintaining invariant its modularity. This size reduction allows the heuristic algorithms that optimize modularity for a better exploration of the modularity landscape. We compare the modularity obtained in several real complex-networks by using the Extremal Optimization algorithm, before and after the size reduction, showing the improvement obtained. We speculate that the proposed analytical size reduction could be extended to an exact coarse graining of the network in the scope of real-space renormalization.

  7. Endovascular repair of bilateral common iliac artery aneurysms using GORE Excluder iliac branch endoprosthesis without aortobi-iliac stent graft conjunction

    PubMed Central

    Ardita, Vincenzo; Giaquinta, Alessia; Veroux, Massimiliano; Sanfiorenzo, Angelo; Virgilio, Carla; D’Arrigo, Giuseppe; Veroux, Pierfrancesco

    2017-01-01

    Abstract Introduction: Bilateral common iliac artery (CIA) aneurysm (CIAA) is a rare entity. In the past decade, different endovascular approaches have been adopted for patients with several comorbidities or unfit for open repair (OR). Recently, the use of iliac branch stent graft has been proposed, resulting in satisfactory patency rates and decrease in morbidity. Currently, according to instruction for use, the iliac branch stent graft is to be used with aortobi-iliac stent graft conjunction. We describe a case of a successful endovascular repair of bilateral CIAAs using the GORE Excluder iliac branch endoprosthesis (IBEs) without aortobi-iliac stent graft conjunction. Case presentation: An 83-year-old man was admitted with abdominal pain and presence of pulsatile mass in the right and left iliac fossa. Computed tomographic (CT) angiography showed the presence of large bilateral CIAAs (right CIA = 66 mm; left CIA = 38 mm), without concomitant thoracic or abdominal aorta aneurysm. Moreover, CT scan demonstrated the presence of bilateral lower accessory renal artery close to the aortic bifurcation. Due to the high operative risk, the patient was scheduled for endovascular repair with bilateral IBEs, without the aortobi-iliac stent graft conjunction to avoid the renal ischemia as a consequence of renal arteries covering. The procedure was completed without complications and duplex ultrasound demonstrated the complete exclusion of both aneurysms without any type of endoleaks at 1 month of follow-up. Conclusions: GORE IBEs without aortobi-iliac stent graft conjunction seem to be a feasible and effective procedure for the treatment of isolated CIAAs in patients with highly selected anatomical conditions. PMID:28207510

  8. [Efficacy of angioplasty of native coarctations of the aorta of the big infant and of the adult with systematic endoprosthesis implantation].

    PubMed

    Fraisse, A; Amabile, N; Errera, J; Aubert, F; Chetaille, P; Kreitmann, B; Metras, D; Durieux, O; Bonnet, J L; Djiane, P

    2004-05-01

    The angioplasty of native coarcatations of the aorta remains a controversial treatment due to recurrences and the potential risk of aneurysm or of descending aorta dissection during catheterization. The interest of a systematic implantation of an endoprothesis is poorly documented. We report our experience in a small series of 3 patients aged from 7, 28 to 52 years at the moment of the angioplasty of their native aortic coarctation. In all the three cases it corresponded to a "membranous" type, localized a the level of the isthmus without hypoplasia of the aortic arch. All presented a refractory hypertension. One patient presented an intermittent claudication related to a low perfusion of lower limbs. The angioplasty was performed with BIB balloon, associated at the same time with the implantation of a Palmaz P308 stent in two cases and Genesis PG2910P in the last patient. The efficacy was immediate in all the 3 cases with stopping antihypertensive drugs at the very day of the procedure. The immediate results were complicated by a bilateral hematoma of the scarpa in a context of excessive anticoagulation in one patient requiring blood tranfusion. After a follow-up of one, 12 and 21 months, all the 3 patients are asymptomatic without any significant residual hypertension. The control scan of the infant confirmed the absence of re-coarctation. In conclusion, the angioplasty followed by systematic implantation of an endoprosthesis is a safe and effective technique for treating simple forms of native coarctations of the aortic isthmus. It can be proposed as a first line treatment for big infants and adults affected by localized types.

  9. Endovascular repair of bilateral common iliac artery aneurysms using GORE Excluder iliac branch endoprosthesis without aortobi-iliac stent graft conjunction: A case report.

    PubMed

    Ardita, Vincenzo; Giaquinta, Alessia; Veroux, Massimiliano; Sanfiorenzo, Angelo; Virgilio, Carla; D'Arrigo, Giuseppe; Veroux, Pierfrancesco

    2017-02-01

    Bilateral common iliac artery (CIA) aneurysm (CIAA) is a rare entity. In the past decade, different endovascular approaches have been adopted for patients with several comorbidities or unfit for open repair (OR). Recently, the use of iliac branch stent graft has been proposed, resulting in satisfactory patency rates and decrease in morbidity. Currently, according to instruction for use, the iliac branch stent graft is to be used with aortobi-iliac stent graft conjunction. We describe a case of a successful endovascular repair of bilateral CIAAs using the GORE Excluder iliac branch endoprosthesis (IBEs) without aortobi-iliac stent graft conjunction. An 83-year-old man was admitted with abdominal pain and presence of pulsatile mass in the right and left iliac fossa. Computed tomographic (CT) angiography showed the presence of large bilateral CIAAs (right CIA = 66 mm; left CIA = 38 mm), without concomitant thoracic or abdominal aorta aneurysm. Moreover, CT scan demonstrated the presence of bilateral lower accessory renal artery close to the aortic bifurcation. Due to the high operative risk, the patient was scheduled for endovascular repair with bilateral IBEs, without the aortobi-iliac stent graft conjunction to avoid the renal ischemia as a consequence of renal arteries covering. The procedure was completed without complications and duplex ultrasound demonstrated the complete exclusion of both aneurysms without any type of endoleaks at 1 month of follow-up. GORE IBEs without aortobi-iliac stent graft conjunction seem to be a feasible and effective procedure for the treatment of isolated CIAAs in patients with highly selected anatomical conditions.

  10. Rational design of efficient modular cells.

    PubMed

    Trinh, Cong T; Liu, Yan; Conner, David J

    2015-11-01

    The modular cell design principle is formulated to devise modular (chassis) cells. These cells can be assembled with exchangeable production modules in a plug-and-play fashion to build microbial cell factories for efficient combinatorial biosynthesis of novel molecules, requiring minimal iterative strain optimization steps. A modular cell is designed to be auxotrophic, containing core metabolic pathways that are necessary but insufficient to support cell growth and maintenance. To be functional, it must tightly couple with an exchangeable production module containing auxiliary metabolic pathways that not only complement cell growth but also enhance production of targeted molecules. We developed a MODCELL (modular cell) framework based on metabolic pathway analysis to implement the modular cell design principle. MODCELL identifies genetic modifications and requirements to construct modular cell candidates and their associated exchangeable production modules. By defining the degree of similarity and coupling metrics, MODCELL can evaluate which exchangeable production module(s) can be tightly coupled with a modular cell candidate. We first demonstrated how MODCELL works in a step-by-step manner for example metabolic networks, and then applied it to design modular Escherichia coli cells for efficient combinatorial biosynthesis of five alcohols (ethanol, propanol, isopropanol, butanol and isobutanol) and five butyrate esters (ethyl butyrate, propyl butyrate, isopropyl butyrate, butyl butyrate and isobutyl butyrate) from pentose sugars (arabinose and xylose) and hexose sugars (glucose, mannose, and galactose) under anaerobic conditions. We identified three modular cells, MODCELL1, MODCELL2 and MODCELL3, that can couple well with Group 1 of modules (ethanol, isobutanol, butanol, ethyl butyrate, isobutyl butyrate, butyl butyrate), Group 2 (isopropanol, isopropyl butyrate), and Group 3 (propanol, isopropanol), respectively. We validated the design of MODCELL1 for anaerobic

  11. Generalized epidemic process on modular networks

    NASA Astrophysics Data System (ADS)

    Chung, Kihong; Baek, Yongjoo; Kim, Daniel; Ha, Meesoon; Jeong, Hawoong

    2014-05-01

    Social reinforcement and modular structure are two salient features observed in the spreading of behavior through social contacts. In order to investigate the interplay between these two features, we study the generalized epidemic process on modular networks with equal-sized finite communities and adjustable modularity. Using the analytical approach originally applied to clique-based random networks, we show that the system exhibits a bond-percolation type continuous phase transition for weak social reinforcement, whereas a discontinuous phase transition occurs for sufficiently strong social reinforcement. Our findings are numerically verified using the finite-size scaling analysis and the crossings of the bimodality coefficient.

  12. A Modular Approach to Redundant Robot Control

    SciTech Connect

    Anderson, R.J.

    1997-12-01

    This paper describes a modular approach for computing redundant robot kinematics. First some conventional redundant control methods are presented and shown to be `passive control laws`, i.e. they can be represented by a network consisting of passive elements. These networks are then put into modular form by applying scattering operator techniques. Additional subnetwork modules can then be added to further shape the motion. Modules for obstacle detection, joint limit avoidance, proximity sensing, and for imposing nonlinear velocity constraints are presented. The resulting redundant robot control system is modular, flexible and robust.

  13. The gravity duals of modular Hamiltonians

    NASA Astrophysics Data System (ADS)

    Jafferis, Daniel L.; Suh, S. Josephine

    2016-09-01

    In this work, we investigate modular Hamiltonians defined with respect to arbitrary spatial regions in quantum field theory states which have semi-classical gravity duals. We find prescriptions in the gravity dual for calculating the action of the modular Hamiltonian on its defining state, including its dual metric, and also on small excitations around the state. Curiously, use of the covariant holographic entanglement entropy formula leads us to the conclusion that the modular Hamiltonian, which in the quantum field theory acts only in the causal completion of the region, does not commute with bulk operators whose entire gauge-invariant description is space-like to the causal completion of the region.

  14. The gravity duals of modular Hamiltonians

    SciTech Connect

    Jafferis, Daniel L.; Suh, S. Josephine

    2016-09-12

    In this study, we investigate modular Hamiltonians defined with respect to arbitrary spatial regions in quantum field theory states which have semi-classical gravity duals. We find prescriptions in the gravity dual for calculating the action of the modular Hamiltonian on its defining state, including its dual metric, and also on small excitations around the state. Curiously, use of the covariant holographic entanglement entropy formula leads us to the conclusion that the modular Hamiltonian, which in the quantum field theory acts only in the causal completion of the region, does not commute with bulk operators whose entire gauge-invariant description is space-like to the causal completion of the region.

  15. Precision Cleaning Titanium Components

    SciTech Connect

    Hand, T.E.; Bohnert, G.W.

    2000-02-02

    Clean bond surfaces are critical to the operation of diffusion bonded titanium engine components. These components can be contaminated with machining coolant, shop dirt, and fingerprints during normal processing and handling. These contaminants must be removed to achieve acceptable bond quality. As environmental concerns become more important in manufacturing, elimination of the use of hazardous materials is desired. For this reason, another process (not using nitric-hydrofluoric acid solution) to clean titanium parts before bonding was sought. Initial cleaning trials were conducted at Honeywell to screen potential cleaning techniques and chemistries. During the initial cleaning process screening phase, Pratt and Whitney provided Honeywell with machined 3 inch x 3 inch x 1 inch titanium test blocks. These test blocks were machined with a water-based machining coolant and exposed to a normal shop environment and handling. (Honeywell sectioned one of these blocks into smaller samples to be used for additional cleanliness verification analyses.) The sample test blocks were ultrasonically cleaned in alkaline solutions and AUGER analysis was used by Honeywell FM and T to validate their cleanliness. This information enabled selection of final cleaning techniques and solutions to be used for the bonding trials. To validate Honeywell's AUGER data and to verify the cleaning processes in actual situations, additional sample blocks were cleaned (using the chosen processes) and then bonded. The bond quality of the test blocks was analyzed according to Pratt and Whitney's requirements. The Charpy impact testing was performed according to ASTM procedure {number_sign}E-23. Bond quality was determined by examining metallographic samples of the bonded test blocks for porosity along the bondline.

  16. Polyisocyanides of titanium.

    PubMed

    Rayón, Víctor M; Redondo, Pilar; Valdés, Haydee; Barrientos, Carmen; Largo, Antonio

    2009-02-26

    Neutral Ti[CN](n) complexes have been investigated with quantum chemistry techniques. According to our theoretical predictions, these complexes are shown to prefer isocyanide arrangements. Therefore, these compounds are good candidates to be the first polyisocyanides to be characterized. The theoretical calculations predict Ti(NC)(4), a methane-like tetrahedral structure with four isocyanide ligands, as the most stable neutral complex. The fact that the isocyanide ligand is a better pi-donor than the cyanide one seems to be the key factor for the preference for isocyanides in neutral titanium complexes.

  17. Process for stabilization of titanium silicide particulates within titanium aluminide containing metal matrix composites

    SciTech Connect

    Christodoulou, L.; Williams, J.C.; Riley, M.A.

    1990-04-10

    This paper describes a method for forming a final composite material comprising titanium silicide particles within a titanium aluminide containing matrix. It comprises: contacting titanium, silicon and aluminum at a temperature sufficient to initiate a reaction between the titanium and silicon to thereby form a first composite comprising titanium silicide particles dispersed within an aluminum matrix; admixing the first composite with titanium and zirconium to form a mixture; heating the mixture to a temperature sufficient to convert at least a portion of the aluminum matrix to titanium aluminide; and recovering a final composite material comprising titanium silicide particles dispersed within a titanium aluminide containing matrix.

  18. Modular optimization code package: MOZAIK

    NASA Astrophysics Data System (ADS)

    Bekar, Kursat B.

    This dissertation addresses the development of a modular optimization code package, MOZAIK, for geometric shape optimization problems in nuclear engineering applications. MOZAIK's first mission, determining the optimal shape of the D2O moderator tank for the current and new beam tube configurations for the Penn State Breazeale Reactor's (PSBR) beam port facility, is used to demonstrate its capabilities and test its performance. MOZAIK was designed as a modular optimization sequence including three primary independent modules: the initializer, the physics and the optimizer, each having a specific task. By using fixed interface blocks among the modules, the code attains its two most important characteristics: generic form and modularity. The benefit of this modular structure is that the contents of the modules can be switched depending on the requirements of accuracy, computational efficiency, or compatibility with the other modules. Oak Ridge National Laboratory's discrete ordinates transport code TORT was selected as the transport solver in the physics module of MOZAIK, and two different optimizers, Min-max and Genetic Algorithms (GA), were implemented in the optimizer module of the code package. A distributed memory parallelism was also applied to MOZAIK via MPI (Message Passing Interface) to execute the physics module concurrently on a number of processors for various states in the same search. Moreover, dynamic scheduling was enabled to enhance load balance among the processors while running MOZAIK's physics module thus improving the parallel speedup and efficiency. In this way, the total computation time consumed by the physics module is reduced by a factor close to M, where M is the number of processors. This capability also encourages the use of MOZAIK for shape optimization problems in nuclear applications because many traditional codes related to radiation transport do not have parallel execution capability. A set of computational models based on the

  19. Coating with a Modular Bone Morphogenetic Peptide Promotes Healing of a Bone-Implant Gap in an Ovine Model

    PubMed Central

    Lu, Yan; Lee, Jae Sung; Nemke, Brett; Graf, Ben K.; Royalty, Kevin; Illgen, Richard; Vanderby, Ray; Markel, Mark D.; Murphy, William L.

    2012-01-01

    Despite the potential for growth factor delivery strategies to promote orthopedic implant healing, there is a need for growth factor delivery methods that are controllable and amenable to clinical translation. We have developed a modular bone growth factor, herein termed “modular bone morphogenetic peptide (mBMP)”, which was designed to efficiently bind to the surface of orthopedic implants and also stimulate new bone formation. The purpose of this study was to coat a hydroxyapatite-titanium implant with mBMP and evaluate bone healing across a bone-implant gap in the sheep femoral condyle. The mBMP molecules efficiently bound to a hydroxyapatite-titanium implant and 64% of the initially bound mBMP molecules were released in a sustained manner over 28 days. The results demonstrated that the mBMP-coated implant group had significantly more mineralized bone filling in the implant-bone gap than the control group in C-arm computed tomography (DynaCT) scanning (25% more), histological (35% more) and microradiographic images (50% more). Push-out stiffness of the mBMP group was nearly 40% greater than that of control group whereas peak force did not show a significant difference. The results of this study demonstrated that mBMP coated on a hydroxyapatite-titanium implant stimulates new bone formation and may be useful to improve implant fixation in total joint arthroplasty applications. PMID:23185610

  20. Hypersensitivity reactions to titanium: diagnosis and management.

    PubMed

    Wood, Megan M; Warshaw, Erin M

    2015-01-01

    Titanium is notable for its biocompatibility and is used as biologic implant material across surgical specialties, especially in metal-sensitive individuals. However, rare cases of titanium hypersensitivity reactions are reported in the literature. This article discusses the properties and biological behavior of titanium and provides a thorough review of the literature on reported cases, diagnostic techniques, and approach to management of titanium hypersensitivity.

  1. Modular Heat Exchanger With Integral Heat Pipe

    NASA Technical Reports Server (NTRS)

    Schreiber, Jeffrey G.

    1992-01-01

    Modular heat exchanger with integral heat pipe transports heat from source to Stirling engine. Alternative to heat exchangers depending on integrities of thousands of brazed joints, contains only 40 brazed tubes.

  2. Modular Solar Electric Power (MSEP) Systems (Presentation)

    SciTech Connect

    Hassani, V.

    2000-06-18

    This presentation discusses the development and deployment of Modular Solar Electric Power (MSEP) systems, the feasibility of application of existing binary power cycles to solar trough technology, and identification of next action items.

  3. Modular digital holographic fringe data processing system

    NASA Technical Reports Server (NTRS)

    Downward, J. G.; Vavra, P. C.; Schebor, F. S.; Vest, C. M.

    1985-01-01

    A software architecture suitable for reducing holographic fringe data into useful engineering data is developed and tested. The results, along with a detailed description of the proposed architecture for a Modular Digital Fringe Analysis System, are presented.

  4. The Modular Structure of Protein Networks

    NASA Astrophysics Data System (ADS)

    Rozenfeld, Hernán D.; Rybski, Diego; Havlin, Shlomo; Makse, Hernán A.

    2008-03-01

    The evolution of the human protein homology network (H-PHN) has led to a complex network that exhibits a surprisingly high level of modularity. Topologically, the H-PHN presents well connected groups (conformed by proteins of similar aminoacid structure) and weak connectivities between the groups. Here, we perform an empirical study of the H-PHN to characterize the degree of modularity in terms of scale-invariant laws using recently introduced box covering algorithms. We find that the exponent that determines the scale-invariance of the modularity is unexpectedly higher than the box dimension of the network. In addition, we perform a percolation analysis that gives insight into the evolutionary process that led to the modular organization and dynamics of the present H-PHN.

  5. Modular solar-heating system - design package

    NASA Technical Reports Server (NTRS)

    Sinton, D. S.

    1979-01-01

    Compilation contains design, performance, and hardware specifications in sufficient detail to fabricate or procure materials and install, operate, and maintain complete modular solar heating and hot water system for single family size dwellings.

  6. 47 CFR 15.212 - Modular transmitters.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... modular transmitter must have their own shielding. The physical crystal and tuning capacitors may be... shielded. The physical crystal and tuning capacitors may be located external to the shielded radio elements...

  7. Modular biowaste monitoring system conceptual design

    NASA Technical Reports Server (NTRS)

    Fogal, G. L.

    1974-01-01

    The objective of the study was to define requirements and generate a conceptual design for a Modular Biowaste Monitoring System for specifically supporting shuttle life science experimental and diagnostic programs.

  8. Modular, Intelligent Power Systems for Space Exploration

    NASA Technical Reports Server (NTRS)

    Button, Robert

    2006-01-01

    NASA's new Space Exploration Initiative demands that vehicles, habitats, and rovers achieve unprecedented levels of reliability, safety, effectiveness, and affordability. Modular and intelligent electrical power systems are critical to achieving those goals. Modular electrical power systems naturally increase reliability and safety through built-in fault tolerance. These modular systems also enable standardization across a multitude of systems, thereby greatly increasing affordability of the programs. Various technologies being developed to support this new paradigm for space power systems will be presented. Examples include the use of digital control in power electronics to enable better performance and advanced modularity functions such as distributed, master-less control and series input power conversion. Also, digital control and robust communication enables new levels of power system control, stability, fault detection, and health management. Summary results from recent development efforts are presented along with expected future technology development needs required to support NASA's ambitious space exploration goals.

  9. The application of SMA spring actuators to a lightweight modular compliant surface bioinspired robot

    NASA Astrophysics Data System (ADS)

    Stone, David L.; Cranney, John; Liang, Robert; Taya, Minoru

    2004-07-01

    The DARPA Sponsored Compliant Surface Robotics (CSR) program pursues development of a high mobility, lightweight, modular, morph-able robot for military forces in the field and for other industrial uses. The USTLAB and University of Washington Center for Intelligent Materials and Systems (CIMS) effort builds on USTLAB proof of concept feasibility studies and demonstration of a 4, 6, or 8 wheeled modular vehicle with articulated leg-wheel assemblies. A collaborative effort between USTLAB and UW-CIMS explored the application of Shape Memory Alloy Nickel Titanium Alloy springs to a leg extension actuator capable of actuating with 4.5 Newton force over a 50 mm stroke. At the completion of Phase II, we have completed mechanical and electronics engineering design and achieved conventional actuation which currently enable active articulation, enabling autonomous reconfiguration for a wide variety of terrains, including upside down operations (in case of flip over), have developed a leg extension actuator demonstration model, and we have positioned our team to pursue a small vehicle with leg extension actuators in follow on work. The CSR vehicle's modular spider-like configuration facilitates adaptation to many uses and compliance over rugged terrain. The developmental process, actuator and vehicle characteristics will be discussed.

  10. Modular modelling with Physiome standards.

    PubMed

    Cooling, Michael T; Nickerson, David P; Nielsen, Poul M F; Hunter, Peter J

    2016-12-01

    The complexity of computational models is increasing, supported by research in modelling tools and frameworks. But relatively little thought has gone into design principles for complex models. We propose a set of design principles for complex model construction with the Physiome standard modelling protocol CellML. By following the principles, models are generated that are extensible and are themselves suitable for reuse in larger models of increasing complexity. We illustrate these principles with examples including an architectural prototype linking, for the first time, electrophysiology, thermodynamically compliant metabolism, signal transduction, gene regulation and synthetic biology. The design principles complement other Physiome research projects, facilitating the application of virtual experiment protocols and model analysis techniques to assist the modelling community in creating libraries of composable, characterised and simulatable quantitative descriptions of physiology. The ability to produce and customise complex computational models has great potential to have a positive impact on human health. As the field develops towards whole-cell models and linking such models in multi-scale frameworks to encompass tissue, organ, or organism levels, reuse of previous modelling efforts will become increasingly necessary. Any modelling group wishing to reuse existing computational models as modules for their own work faces many challenges in the context of construction, storage, retrieval, documentation and analysis of such modules. Physiome standards, frameworks and tools seek to address several of these challenges, especially for models expressed in the modular protocol CellML. Aside from providing a general ability to produce modules, there has been relatively little research work on architectural principles of CellML models that will enable reuse at larger scales. To complement and support the existing tools and frameworks, we develop a set of principles to

  11. Titanium in 1980

    NASA Astrophysics Data System (ADS)

    Minkler, Ward W.

    1981-04-01

    Much attention is being focused on the availability and use of non-fuel minerals in the United States. Because of the rapid increase in demand since 1978, titanium has been one of the much-publicized metals in this group. Sponge producers are now expanding sponge manufacturing plants to meet this greater demand, and it now appears that there could be a surplus of sponge in 1981. A delay in airplane purchases caused by severe operating losses of the airlines could have a significant effect on mill product shipments in 1981. However, there is no reason to believe that titanium has reached maturity as a structural aerospace or industrial metal. While it is unreasonable to anticipate that demand will continue to grow at the same rate experienced between 1978 and 1980, new greenfield capacity will nevertheless be required in the early 1980s. Two basic issues must be resolved before such ventures become reality: 1) choice of process; and 2) method for financing, either public or private. Both will be the subject of study and debate in 1981.

  12. Compaction of Titanium Powders

    SciTech Connect

    Gerdemann, Stephen,J; Jablonski, Paul, J

    2011-05-01

    Accurate modeling of powder densification has been an area of active research for more than 60 years. The earliest efforts were focused on linearization of the data because computers were not readily available to assist with curve-fitting methods. In this work, eight different titanium powders (three different sizes of sponge fines<150 {micro}m,<75 {micro}m, and<45 {micro}m; two different sizes of a hydride-dehydride [HDH]<75 {micro}m and<45 {micro}m; an atomized powder; a commercially pure [CP] Ti powder from International Titanium Powder [ITP]; and a Ti 6 4 alloy powder) were cold pressed in a single-acting die instrumented to collect stress and deformation data during compaction. From these data, the density of each compact was calculated and then plotted as a function of pressure. The results show that densification of all the powders, regardless of particle size, shape, or chemistry, can be modeled accurately as the sum of an initial density plus the sum of a rearrangement term and a work-hardening term. These last two terms are found to be a function of applied pressure and take the form of an exponential rise.

  13. Electrorotation of titanium microspheres.

    PubMed

    Arcenegui, Juan J; Ramos, Antonio; García-Sánchez, Pablo; Morgan, Hywel

    2013-04-01

    Electrorotation (ROT) data for solid titanium micrometer-sized spheres in an electrolyte are presented for three different ionic conductivities, over the frequency range of 10 Hz to 100 kHz. The direction of rotation was found to be opposite to the direction of rotation of the electric field vector (counterfield electrorotation), with a single rotation peak. The maximum rotation rate occurs at a frequency of the order of the reciprocal RC time constant for charging the particle double layer capacitance through the resistor of the electrolyte bulk. A model for the electrical torque acting on a metallic sphere is presented, using a constant phase element impedance to describe the metal/electrolyte interface. The titanium spheres are much denser than the electrolyte and rest on the bottom substrate. Therefore, the electrical and viscous torques near a wall are considered in the analysis. Good agreement is found between the predicted and measured rotational speed as a function of frequency. Theory shows that there is no effect of induced charge electroosmotic flow on the ROT, as observed experimentally.

  14. Compaction of Titanium Powders

    SciTech Connect

    Stephen J. Gerdemann; Paul D. Jablonski

    2010-11-01

    Accurate modeling of powder densification has been an area of active research for more than 60 years. The earliest efforts were focused on linearization of the data because computers were not readily available to assist with curve-fitting methods. In this work, eight different titanium powders (three different sizes of sponge fines <150 μm, <75 μm, and < 45 μm; two different sizes of a hydride-dehydride [HDH] <75 μm and < 45 μm; an atomized powder; a commercially pure [CP] Ti powder from International Titanium Powder [ITP]; and a Ti 6 4 alloy powder) were cold pressed in a single-acting die instrumented to collect stress and deformation data during compaction. From these data, the density of each compact was calculated and then plotted as a function of pressure. The results show that densification of all the powders, regardless of particle size, shape, or chemistry, can be modeled accurately as the sum of an initial density plus the sum of a rearrangement term and a work-hardening term. These last two terms are found to be a function of applied pressure and take the form of an exponential rise.

  15. Optimal Network Modularity for Information Diffusion

    NASA Astrophysics Data System (ADS)

    Nematzadeh, Azadeh; Ferrara, Emilio; Flammini, Alessandro; Ahn, Yong-Yeol

    2014-08-01

    We investigate the impact of community structure on information diffusion with the linear threshold model. Our results demonstrate that modular structure may have counterintuitive effects on information diffusion when social reinforcement is present. We show that strong communities can facilitate global diffusion by enhancing local, intracommunity spreading. Using both analytic approaches and numerical simulations, we demonstrate the existence of an optimal network modularity, where global diffusion requires the minimal number of early adopters.

  16. Modular Programming Techniques for Distributed Computing Tasks

    DTIC Science & Technology

    2004-08-01

    Modular Programming Techniques for Distributed Computing Tasks Anthony Cowley, Hwa-Chow Hsu, Camillo J. Taylor GRASP Laboratory University of...network, distributed computing , software design 1. INTRODUCTION As efforts to field sensor networks, or teams of mobile robots, become more...TITLE AND SUBTITLE Modular Programming Techniques for Distributed Computing Tasks 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER

  17. Adaptive Coupled Oscillators for Modular Robots

    NASA Astrophysics Data System (ADS)

    Hartono, Pitoyo; Nakane, Aito

    In this research we physically built several robotics modules that are able to self-discover a connection topology which allows them to generate a coordinated behavior as an integrated modular robot. We consider that this self-configurability of hardware module can potentially simplify the costly designing process of complicated robots and at the same time improve the resiliency of modular robots in the face of internal and external changes.

  18. [Importance of neurobiology for modular psychotherapy].

    PubMed

    Schmahl, C; Bohus, M

    2013-11-01

    In the context of continuing education in psychiatry and psychotherapy, modular psychotherapy is of special importance. In modular psychotherapy, general interventions, e.g. for regulation of emotions, have an important function. In this review examples are given to describe the importance of neurobiology for the understanding and the improvement of these mechanisms. In addition, the use of neurobiological investigations within classical psychotherapy trials in the fields of borderline personality disorder and posttraumatic stress disorder will be depicted.

  19. A 3-d modular gripper design tool

    SciTech Connect

    Brown, R.G.; Brost, R.C.

    1997-01-01

    Modular fixturing kits are precisely machined sets of components used for flexible, short-turnaround construction of fixtures for a variety of manufacturing purposes. A modular vise is a parallel-jaw vise, where each jaw is a modular fixture plate with a regular grid of precisely positioned holes. A modular vise can be used to locate and hold parts for machining, assembly, and inspection tasks. To fixture a part, one places pins in some of the holes so that when the vise is closed, the part is reliably located and completely constrained. The modular vise concept can be adapted easily to the design of modular parallel-jaw grippers for robots. By attaching a grid plate to each jaw of a parallel-jaw gripper, the authors gain the ability to easily construct high-quality grasps for a wide variety of parts from a standard set of hardware. Wallack and Canny developed a previous algorithm for planning planar grasp configurations for the modular vise. In this paper, the authors expand this work to produce a 3-d fixture/gripper design tool. They describe several analyses added to the planar algorithm to improve its utility, including a three-dimensional grasp quality metric based on geometric and force information, three-dimensional geometric loading analysis, and inter-gripper interference analysis to determine the compatibility of multiple grasps for handing the part from one gripper to another. Finally, the authors describe two applications which combine the utility of modular vise-style grasping with inter-gripper interference: The first is the design of a flexible part-handling subsystem for a part cleaning workcell under development at Sandia National Laboratories; the second is the automatic design of grippers that support the assembly of multiple products on a single assembly line.

  20. A 3-d modular gripper design tool

    SciTech Connect

    Brown, R.G.; Brost, R.C.

    1997-02-01

    Modular fixturing kits are sets of components used for flexible, rapid construction of fixtures. A modular vise is a parallel-jaw vise, each jaw of which is a modular fixture plate with a regular grid of precisely positioned holes. To fixture a part, one places pins in some of the holes so that when the vise is closed, the part is reliably located and completely constrained. The modular vise concept can be adapted easily to the design of modular parallel-jaw grippers for robots. By attaching a grid-plate to each jaw of a parallel-jaw gripper, one gains the ability to easily construct high-quality grasps for a wide variety of parts from a standard set of hardware. Wallack and Canny developed an algorithm for planning planar grasp configurations for the modular vise. In this paper, the authors expand this work to produce a 3-d fixture/gripper design tool. They describe several analyses they have added to the planar algorithm, including a 3-d grasp quality metric based on force information, 3-d geometric loading analysis, and inter-gripper interference analysis. Finally, the authors describe two applications of their code. One of these is an internal application at Sandia, while the other shows a potential use of the code for designing part of an agile assembly line.

  1. Evolution of Complex Modular Biological Networks

    PubMed Central

    Hintze, Arend; Adami, Christoph

    2008-01-01

    Biological networks have evolved to be highly functional within uncertain environments while remaining extremely adaptable. One of the main contributors to the robustness and evolvability of biological networks is believed to be their modularity of function, with modules defined as sets of genes that are strongly interconnected but whose function is separable from those of other modules. Here, we investigate the in silico evolution of modularity and robustness in complex artificial metabolic networks that encode an increasing amount of information about their environment while acquiring ubiquitous features of biological, social, and engineering networks, such as scale-free edge distribution, small-world property, and fault-tolerance. These networks evolve in environments that differ in their predictability, and allow us to study modularity from topological, information-theoretic, and gene-epistatic points of view using new tools that do not depend on any preconceived notion of modularity. We find that for our evolved complex networks as well as for the yeast protein–protein interaction network, synthetic lethal gene pairs consist mostly of redundant genes that lie close to each other and therefore within modules, while knockdown suppressor gene pairs are farther apart and often straddle modules, suggesting that knockdown rescue is mediated by alternative pathways or modules. The combination of network modularity tools together with genetic interaction data constitutes a powerful approach to study and dissect the role of modularity in the evolution and function of biological networks. PMID:18266463

  2. Managing in an age of modularity.

    PubMed

    Baldwin, C Y; Clark, K B

    1997-01-01

    Modularity is a familiar principle in the computer industry. Different companies can independently design and produce components, suck as disk drives or operating software, and those modules will fit together into a complex and smoothly functioning product because the module makers obey a given set of design rules. Modularity in manufacturing is already common in many companies. But now a number of them are beginning to extend the approach into the design of their products and services. Modularity in design should tremendously boost the rate of innovation in many industries as it did in the computer industry. As businesses as diverse as auto manufacturing and financial services move toward modular designs, the authors say, competitive dynamics will change enormously. No longer will assemblers control the final product: suppliers of key modules will gain leverage and even take on responsibility for design rules. Companies will compete either by specifying the dominant design rules (as Microsoft does) or by producing excellent modules (as disk drive maker Quantum does). Leaders in a modular industry will control less, so they will have to watch the competitive environment closely for opportunities to link up with other module makers. They will also need to know more: engineering details that seemed trivial at the corporate level may now play a large part in strategic decisions. Leaders will also become knowledge managers internally because they will need to coordinate the efforts of development groups in order to keep them focused on the modular strategies the company is pursuing.

  3. Theory for the Emergence of Modularity in Complex Systems

    NASA Astrophysics Data System (ADS)

    Deem, Michael; Park, Jeong-Man

    2013-03-01

    Biological systems are modular, and this modularity evolves over time and in different environments. A number of observations have been made of increased modularity in biological systems under increased environmental pressure. We here develop a theory for the dynamics of modularity in these systems. We find a principle of least action for the evolved modularity at long times. In addition, we find a fluctuation dissipation relation for the rate of change of modularity at short times. We discuss a number of biological and social systems that can be understood with this framework. The modularity of the protein-protein interaction network increases when yeast are exposed to heat shock, and the modularity of the protein-protein networks in both yeast and E. coli appears to have increased over evolutionary time. Food webs in low-energy, stressful environments are more modular than those in plentiful environments, arid ecologies are more modular during droughts, and foraging of sea otters is more modular when food is limiting. The modularity of social networks changes over time: stock brokers instant messaging networks are more modular under stressful market conditions, criminal networks are more modular under increased police pressure, and world trade network modularity has decreased

  4. Modular Wideband Active Vibration Absorber

    NASA Technical Reports Server (NTRS)

    Smith, David R.; Zewari, Wahid; Lee, Kenneth Y.

    1999-01-01

    A comparison of space experiments with previous missions shows a common theme. Some of the recent experiments are based on the scientific fundamentals of instruments of prior years. However, the main distinguishing characteristic is the embodiment of advances in engineering and manufacturing in order to extract clearer and sharper images and extend the limits of measurement. One area of importance to future missions is providing vibration free observation platforms at acceptable costs. It has been shown by researchers that vibration problems cannot be eliminated by passive isolation techniques alone. Therefore, various organizations have conducted research in the area of combining active and passive vibration control techniques. The essence of this paper is to present progress in what is believed to be a new concept in this arena. It is based on the notion that if one active element in a vibration transmission path can provide a reasonable vibration attenuation, two active elements in series may provide more control options and better results. The paper presents the functions of a modular split shaft linear actuator developed by NASA's Goddard Space Flight Center and University of Massachusetts Lowell. It discusses some of the control possibilities facilitated by the device. Some preliminary findings and problems are also discussed.

  5. The TOTEM modular trigger system

    NASA Astrophysics Data System (ADS)

    Bagliesi, M. G.; Berretti, M.; Cecchi, R.; Greco, V.; Lami, S.; Latino, G.; Oliveri, E.; Pedreschi, E.; Scribano, A.; Spinella, F.; Turini, N.

    2010-05-01

    The TOTEM experiment will measure the total cross-section with the luminosity independent method and study elastic and diffractive scattering at the LHC. We are developing a modular trigger system, based on programmable logic, that will select meaningful events within 2.5 μs. The trigger algorithm is based on a tree structure in order to obtain information compression. The trigger primitive is generated directly on the readout chip, VFAT, that has a specific fast output that gives low resolution hits information. In two of the TOTEM detectors, Roman Pots and T2, a coincidence chip will perform track recognition directly on the detector readout boards, while for T1 the hits are transferred from the VFATs to the trigger hardware. Starting from more than 2000 bits delivered by the detector electronics, we extract, in a first step, six trigger patterns of 32 LVDS signals each; we build, then, on a dedicated board, a 1-bit (L1) trigger signal for the TOTEM experiment and 16 trigger bits to the CMS experiment global trigger system for future common data taking.

  6. Modular verification of concurrent systems

    SciTech Connect

    Sobel, A.E.K.

    1986-01-01

    During the last ten years, a number of authors have proposed verification techniques that allow one to prove properties of individual processes by using global assumptions about the behavior of the remaining processes in the distributed program. As a result, one must justify these global assumptions before drawing any conclusions regarding the correctness of the entire program. This justification is often the most difficult part of the proof and presents a serious obstacle to hierarchical program development. This thesis develops a new approach to the verification of concurrent systems. The approach is modular and supports compositional development of programs since the proofs of each individual process of a program are completely isolated from all others. The generality of this approach is illustrated by applying it to a representative set of contemporary concurrent programming languages, namely: CSP, ADA, Distributed Processes, and a shared variable language. In addition, it is also shown how the approach may be used to deal with a number of other constructs that have been proposed for inclusion in concurrent languages: FORK and JOIN primitives, nested monitor calls, path expressions, atomic transactions, and asynchronous message passing. These results allow argument that the approach is universal and can be used to design proof systems for any concurrent language.

  7. Fitness, environmental changes and the growth of modularity- a quasispecies theory for the evolutionary dynamics of modularity

    NASA Astrophysics Data System (ADS)

    Niestemski, Liang; Park, Jeong-Man; Deem, Michael

    2015-03-01

    Although the modularity of a biological system is demonstrated and recognized, the evolution of the modularity is not well understood. We here present a quasispecies theory for the evolutionary dynamics of modularity. Complemented with numerical models, this analytical theory shows the calculation of the steady-state fitness in a randomly changing environment, the relationship between rate of environmental changes and rate of growth of modularity, as well as a principle of least action for the evolved modularity at steady state.

  8. Diffusion bonding of titanium-titanium aluminide-alumina sandwich

    SciTech Connect

    Wickman, H.A.; Chin, E.S.C.; Biederman, R.R.

    1995-12-31

    Diffusion bonding of a metallic-intermetallic-ceramic sandwich is of interest for potential armor applications. Low cost titanium, titanium diboride reinforced titanium aluminide (Ti-48at.%Al), and aluminum oxide are diffusion bonded in a vacuum furnace between 1,000 C and 1,400 C. Metallographic examination of the prior bonding interface showed excellent metallurgical coupling between the Ti-48at.%Al composite and the low cost Ti. A series of microstructures representative of phases consistent with a hypothetical Ti-Al-B phase diagram is visible. The alumina-Ti-48at.%Al interfacial bond is achieved through penetration of titanium-aluminum phases into the existing alumina porosity. A detailed microstructural analysis identifying mechanisms of interfacial bonding will be presented for each interfacial zone.

  9. Beta titanium alloys and their role in the titanium industry

    NASA Astrophysics Data System (ADS)

    Bania, Paul J.

    1994-07-01

    The class of titanium alloys generically referred to as the beta alloys is arguably the most versatile in the titanium family. Since these alloys offer the highest strength-to-weight ratios and deepest hardenability of all titanium alloys, one might expect them to compete favorably for a variety of aerospace applications. To the contrary, however, except for one very successful application (Ti-13V-11Cr-3Al on the SR-71), the beta alloys have remained a very small segment of the industry. As a perspective on this situation, this article reviews some past and present applications of titanium alloys. It also descibes some unique new alloys and applications that promise to reverse historical trends.

  10. Direct influence of titanium and zirconia particles on the morphology and functionality of mature human osteoclasts.

    PubMed

    Pasold, Juliane; Markhoff, Jana; Tillmann, Jenny; Krogull, Martin; Pisowocki, Phillip; Bader, Rainer

    2017-09-01

    Within the last ten years of biomedical implants, the focus is increasingly on bioceramics, specifically on zirconia (ZrO2 ). Hence, we analyzed the impact of ZrO2 particles in comparison to titanium particles on mature human osteoclasts (OCs) as little is known about the direct effect of wear particles on mature OCs and their role in the osteolytic process during aseptic endoprosthesis loosening. Changes in cell morphology and functionality of OCs incubated with particles in different concentrations were investigated in vitro. OCs tend to be enlarged after three days of cultivation with both types of particles, especially with high concentrations of ZrO2 , suggesting increased cell fusion. Further, we identified significantly increased expression of OC specific and bone matrix related genes: VNR, RANK, TRAP, and CTSK pointing on a direct stimulatory particle effect on the functionality of mature OCs. In completion, we quantified the bone resorption activity of particle treated mature OCs but could not detect a significant difference in bone resorption compared to OCs cultivated without particles. However, we could identify significantly higher gene expression of MMP-1 in particle treated OCs compared to untreated control OCs after three days of incubation. We also detected an impaired production of the tissue inhibitor of metalloproteinase, especially for OCs treated with high ZrO2 concentrations. In conclusion, our in vitro data show that abrasion particles could have a direct influence on mature OCs and therefore could promote increased OC-mediated bone resorption during aseptic loosening of total joint replacements. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2608-2615, 2017. © 2017 Wiley Periodicals, Inc.

  11. Hemocompatibility of titanium nitride.

    PubMed

    Dion, I; Baquey, C; Candelon, B; Monties, J R

    1992-10-01

    The left ventricular assist device is based on the principle of the Maillard-Wenkel rotative pump. The materials which make up the pump must present particular mechanical, tribological, thermal and chemical properties. Titanium nitride (TiN) because of its surface properties and graphite because of its bulk characteristics have been chosen. The present study evaluated the in vitro hemocompatibility of TiN coating deposited by the chemical vapor deposition process. Protein adsorption, platelet retention and hemolysis tests have been carried out. In spite of some disparities, the TiN behavior towards albumin and fibrinogen is interesting, compared with the one of a reference medical grade elastomer. The platelet retention test gives similar results as those achieved with the same elastomer. The hemolysis percentage is near to zero. TiN shows interesting characteristics, as far as mechanical and tribological problems are concerned, and presents very encouraging blood tolerability properties.

  12. Advanced titanium processing

    SciTech Connect

    Hartman, Alan D.; Gerdemann, Stephen J.; Schrems, Karol K.; Holcomb, Gordon R.; Argetsinger, Edward R.; Hansen, Jeffrey S.; Paige, Jack I.; Turner, Paul C.

    2001-01-01

    The Albany Research Center of the U.S. Department of Energy has been investigating a means to form useful wrought products by direct and continuous casting of titanium bars using cold-wall induction melting rather than current batch practices such as vacuum arc remelting. Continuous ingots produced by cold-wall induction melting, utilizing a bottomless water-cooled copper crucible, without slag (CaF2) additions had minor defects in the surface such as ''hot tears''. Slag additions as low as 0.5 weight percent were used to improve the surface finish. Therefore, a slag melted experimental Ti-6Al-4V alloy ingot was compared to a commercial Ti-6Al-4V alloy ingot in the areas of physical, chemical, mechanical, and corrosion attributes to address the question, ''Are any detrimental effects caused by slag addition''?

  13. Gamma titanium aluminide alloys

    SciTech Connect

    Yamaguchi, M.; Inui, H.; Kishida, K.; Matsumuro, M.; Shirai, Y.

    1995-08-01

    Extensive progress and improvements have been made in the science and technology of gamma titanium aluminide alloys within the last decade. In particular, the understanding of their microstructural characteristics and property/microstructure relationships has been substantially deepened. Based on these achievements, various engineering two-phase gamma alloys have been developed and their mechanical and chemical properties have been assessed. Aircraft and automotive industries arc pursuing their introduction for various structural components. At the same time, recent basic studies on the mechanical properties of two-phase gamma alloys, in particular with a controlled lamellar structure have provided a considerable amount of fundamental information on the deformation and fracture mechanisms of the two-phase gamma alloys. The results of such basic studies are incorporated in the recent alloy and microstructure design of two-phase gamma alloys. In this paper, such recent advances in the research and development of the two-phase gamma alloys and industrial involvement are summarized.

  14. Hydrogen in titanium alloys

    SciTech Connect

    Wille, G W; Davis, J W

    1981-04-01

    The titanium alloys that offer properties worthy of consideration for fusion reactors are Ti-6Al-4V, Ti-6Al-2Sn-4Zr-2Mo-Si (Ti-6242S) and Ti-5Al-6Sn-2Zr-1Mo-Si (Ti-5621S). The Ti-6242S and Ti-5621S are being considered because of their high creep resistance at elevated temperatures of 500/sup 0/C. Also, irradiation tests on these alloys have shown irradiation creep properties comparable to 20% cold worked 316 stainless steel. These alloys would be susceptible to slow strain rate embrittlement if sufficient hydrogen concentrations are obtained. Concentrations greater than 250 to 500 wppm hydrogen and temperatures lower than 100 to 150/sup 0/C are approximate threshold conditions for detrimental effects on tensile properties. Indications are that at the elevated temperature - low hydrogen pressure conditions of the reactors, there would be negligible hydrogen embrittlement.

  15. Design and Operation of an Optically-Accessible Modular Reactor for Diagnostics of Thermal Thin Film Deposition Processes

    PubMed Central

    Kimes, W. A.; Sperling, B. A.; Maslars, J. E.

    2015-01-01

    The design and operation of a simple, optically-accessible modular reactor for probing thermal thin film deposition processes, such as atomic layer deposition processes (ALD) and chemical vapor deposition (CVD), is described. This reactor has a nominal footprint of 225 cm2 and a mass of approximately 6.6 kg, making it small enough to conveniently function as a modular component of an optical train. The design is simple, making fabrication straightforward and relatively inexpensive. Reactor operation is characterized using two infrared absorption measurements to determine exhaust times for tetrakis(dimethylamino)titanium and water, proto-typical ALD precursors, in a pressure and flow regime commonly used for ALD. PMID:26958438

  16. Advanced Modular Inverter Technology Development

    SciTech Connect

    Adam Szczepanek

    2006-02-04

    Electric and hybrid-electric vehicle systems require an inverter to convert the direct current (DC) output of the energy generation/storage system (engine, fuel cells, or batteries) to the alternating current (AC) that vehicle propulsion motors use. Vehicle support systems, such as lights and air conditioning, also use the inverter AC output. Distributed energy systems require an inverter to provide the high quality AC output that energy system customers demand. Today's inverters are expensive due to the cost of the power electronics components, and system designers must also tailor the inverter for individual applications. Thus, the benefits of mass production are not available, resulting in high initial procurement costs as well as high inverter maintenance and repair costs. Electricore, Inc. (www.electricore.org) a public good 501 (c) (3) not-for-profit advanced technology development consortium assembled a highly qualified team consisting of AeroVironment Inc. (www.aerovironment.com) and Delphi Automotive Systems LLC (Delphi), (www.delphi.com), as equal tiered technical leads, to develop an advanced, modular construction, inverter packaging technology that will offer a 30% cost reduction over conventional designs adding to the development of energy conversion technologies for crosscutting applications in the building, industry, transportation, and utility sectors. The proposed inverter allows for a reduction of weight and size of power electronics in the above-mentioned sectors and is scalable over the range of 15 to 500kW. The main objective of this program was to optimize existing AeroVironment inverter technology to improve power density, reliability and producibility as well as develop new topology to reduce line filter size. The newly developed inverter design will be used in automotive and distribution generation applications. In the first part of this program the high-density power stages were redesigned, optimized and fabricated. One of the main tasks

  17. Teleoperated Modular Robots for Lunar Operations

    NASA Technical Reports Server (NTRS)

    Globus, Al; Hornby, Greg; Larchev, Greg; Hancher, Matt; Cannon, Howard; Lohn, Jason

    2004-01-01

    Solar system exploration is currently carried out by special purpose robots exquisitely designed for the anticipated tasks. However, all contingencies for in situ resource utilization (ISRU), human habitat preparation, and exploration will be difficult to anticipate. Furthermore, developing the necessary special purpose mechanisms for deployment and other capabilities is difficult and error prone. For example, the Galileo high gain antenna never opened, severely restricting the quantity of data returned by the spacecraft. Also, deployment hardware is used only once. To address these problems, we are developing teleoperated modular robots for lunar missions, including operations in transit from Earth. Teleoperation of lunar systems from Earth involves a three second speed-of-light delay, but experiment suggests that interactive operations are feasible.' Modular robots typically consist of many identical modules that pass power and data between them and can be reconfigured for different tasks providing great flexibility, inherent redundancy and graceful degradation as modules fail. Our design features a number of different hub, link, and joint modules to simplify the individual modules, lower structure cost, and provide specialized capabilities. Modular robots are well suited for space applications because of their extreme flexibility, inherent redundancy, high-density packing, and opportunities for mass production. Simple structural modules can be manufactured from lunar regolith in situ using molds or directed solar sintering. Software to direct and control modular robots is difficult to develop. We have used genetic algorithms to evolve both the morphology and control system for walking modular robots3 We are currently using evolvable system technology to evolve controllers for modular robots in the ISS glove box. Development of lunar modular robots will require software and physical simulators, including regolith simulation, to enable design and test of robot

  18. Endomorphisms on half-sided modular inclusions

    SciTech Connect

    Svegstrup, Rolf Dyre

    2006-12-15

    In algebraic quantum field theory we consider nets of von Neumann algebras indexed over regions of the space time. Wiesbrock [''Conformal quantum field theory and half-sided modular inclusions of von Neumann algebras,'' Commun. Math. Phys. 158, 537-543 (1993)] has shown that strongly additive nets of von Neumann algebras on the circle are in correspondence with standard half-sided modular inclusions. We show that a finite index endomorphism on a half-sided modular inclusion extends to a finite index endomorphism on the corresponding net of von Neumann algebras on the circle. Moreover, we present another approach to encoding endomorphisms on nets of von Neumann algebras on the circle into half-sided modular inclusions. There is a natural way to associate a weight to a Moebius covariant endomorphism. The properties of this weight have been studied by Bertozzini et al. [''Covariant sectors with infinite dimension and positivity of the energy,'' Commun. Math. Phys. 193, 471-492 (1998)]. In this paper we show the converse, namely, how to associate a Moebius covariant endomorphism to a given weight under certain assumptions, thus obtaining a correspondence between a class of weights on a half-sided modular inclusion and a subclass of the Moebius covariant endomorphisms on the associated net of von Neumann algebras. This allows us to treat Moebius covariant endomorphisms in terms of weights on half-sided modular inclusions. As our aim is to provide a framework for treating endomorphisms on nets of von Neumann algebras in terms of the apparently simpler objects of weights on half-sided modular inclusions, we lastly give some basic results for manipulations with such weights.

  19. Local modularity for community detection in complex networks

    NASA Astrophysics Data System (ADS)

    Xiang, Ju; Hu, Tao; Zhang, Yan; Hu, Ke; Li, Jian-Ming; Xu, Xiao-Ke; Liu, Cui-Cui; Chen, Shi

    2016-02-01

    Community detection is a topic of interest in the study of complex networks such as the protein-protein interaction networks and metabolic networks. In recent years, various methods were proposed to detect community structures of the networks. Here, a kind of local modularity with tunable parameter is derived from the Newman-Girvan modularity by a special self-loop strategy that depends on the community division of the networks. By the self-loop strategy, one can easily control the definition of modularity, and the resulting modularity can be optimized by using the existing modularity optimization algorithms. The local modularity is used as the target function for community detection, and a self-consistent method is proposed for the optimization of the local modularity. We analyze the behaviors of the local modularity and show the validity of the local modularity in detecting community structures on various networks.

  20. Robust modular product family design

    NASA Astrophysics Data System (ADS)

    Jiang, Lan; Allada, Venkat

    2001-10-01

    This paper presents a modified Taguchi methodology to improve the robustness of modular product families against changes in customer requirements. The general research questions posed in this paper are: (1) How to effectively design a product family (PF) that is robust enough to accommodate future customer requirements. (2) How far into the future should designers look to design a robust product family? An example of a simplified vacuum product family is used to illustrate our methodology. In the example, customer requirements are selected as signal factors; future changes of customer requirements are selected as noise factors; an index called quality characteristic (QC) is set to evaluate the product vacuum family; and the module instance matrix (M) is selected as control factor. Initially a relation between the objective function (QC) and the control factor (M) is established, and then the feasible M space is systemically explored using a simplex method to determine the optimum M and the corresponding QC values. Next, various noise levels at different time points are introduced into the system. For each noise level, the optimal values of M and QC are computed and plotted on a QC-chart. The tunable time period of the control factor (the module matrix, M) is computed using the QC-chart. The tunable time period represents the maximum time for which a given control factor can be used to satisfy current and future customer needs. Finally, a robustness index is used to break up the tunable time period into suitable time periods that designers should consider while designing product families.

  1. Modular Manufacturing Simulator: Users Manual

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The Modular Manufacturing Simulator (MMS) has been developed for the beginning user of computer simulations. Consequently, the MMS cannot model complex systems that require branching and convergence logic. Once a user becomes more proficient in computer simulation and wants to add more complexity, the user is encouraged to use one of the many available commercial simulation systems. The (MMS) is based on the SSE5 that was developed in the early 1990's by the University of Alabama in Huntsville (UAH). A recent survey by MSFC indicated that the simulator has been a major contributor to the economic impact of the MSFC technology transfer program. Many manufacturers have requested additional features for the SSE5. Consequently, the following features have been added to the MMS that are not available in the SSE5: runs under Windows, print option for both input parameters and output statistics, operator can be fixed at a station or assigned to a group of stations, operator movement based on time limit, part limit, or work-in-process (WIP) limit at next station. The movement options for a moveable operators are: go to station with largest WIP, rabbit chase where operator moves in circular sequence between stations, and push/pull where operator moves back and forth between stations. This user's manual contains the necessary information for installing the MMS on a PC, a description of the various MMS commands, and the solutions to a number of sample problems using the MMS. Also included in the beginning of this report is a brief discussion of technology transfer.

  2. Brazing titanium to stainless steel

    NASA Technical Reports Server (NTRS)

    Batista, R. I.

    1980-01-01

    Titanium and stainless-steel members are usually joined mechanically for lack of any other effective method. New approach using different brazing alloy and plating steel member with nickel resolves problem. Process must be carried out in inert atmosphere.

  3. A "clickable" titanium surface platform.

    PubMed

    Watson, Matthew A; Lyskawa, Joël; Zobrist, Cédric; Fournier, David; Jimenez, Maude; Traisnel, Michel; Gengembre, Léon; Woisel, Patrice

    2010-10-19

    A straightforward functionalization of a titanium surface using "click" chemistry is reported. A "clickable" titanium surface platform was prepared by the immobilization of an azide-functionalized electroactive catechol anchor and was subsequently derivatized with an electroactive or fluorinated probe via the CuAAC (copper-catalyzed azide-alkyne cycloaddition) reaction. The course of the reaction was investigated by contact angle, XPS, and electrochemical measurements.

  4. Slow Speed Machining of Titanium

    DTIC Science & Technology

    1981-10-01

    MRL-R-833 SLOW SPEED MACHINING OF TITANIUM D.M. Turley Approved for Public Release I -J C) COMMONWEALTH OF AUSTRALIA 1981 OCTOBER, 1981 82ോ 20 059...DEPARTMENT OF DEFENCE MATERIALS RESEARCH LABORATORIES REPORT MRL-R-833 SLOW SPEED MACHINING OF TITANIUM D.M. Turley ABSTRACT Catastrophic-shear type...MRL-R-833 b. Title in isolation: UNCLASSIFIED c. Report Number: MRL-R-833 c. Abstract in isolation: UNCLASSIFIED 3. TITLE: SLOW SPEED MACHINING OF

  5. Low cost titanium--myth or reality

    SciTech Connect

    Turner, Paul C.; Hartman, Alan D.; Hansen, Jeffrey S.; Gerdemann, Stephen J.

    2001-01-01

    In 1998, approximately 57,000 tons of titanium metal was consumed in the form of mill products (1). Only about 5% of the 4 million tons of titanium minerals consumed each year is used to produce titanium metal, with the remainder primarily used to produce titanium dioxide pigment. Titanium metal production is primarily based on the direct chlorination of rutile to produce titanium tetrachloride, which is then reduced to metal using the Kroll magnesium reduction process. The use of titanium is tied to its high strength-to-weight ratio and corrosion resistance. Aerospace is the largest application for titanium, and titanium cost has prevented its use in non-aerospace applications including the automotive and heavy vehicle industries.

  6. [Modular psychotherapy with children and adolescents].

    PubMed

    Schmidt, Stefanie J; Schimmelmann, Benno G

    2016-11-01

    The implementation of evidence-based psychotherapy with children and adolescents has been limited so far. This is mainly due to the fact that patients in service settings tend to have higher rates of comorbidities and more frequently changing therapy needs than those in research settings. Thus, modular psychotherapies are promising, as they allow the treatment protocol to be adapted to patients’ individual needs. Because no review on modular psychotherapy for children and adolescents exists, we conducted a systematic literature research. The results of the 15 randomized controlled trials identified demonstrate that modular psychotherapy is associated with significant reductions in symptom levels as well as with higher rates of diagnostic remission compared to control conditions. Because of the lack of evidence, future studies should investigate the incremental efficacy of modular approaches and test the validity of underlying theoretical models as well as of decision flowcharts. Modular psychotherapy approaches have the potential to personalize evidence-based interventions for children and adolescents across various therapeutical traditions, and to facilitate their implementation into clinical practice.

  7. Interfacial reactions in titanium-matrix composites

    SciTech Connect

    Yang, J.M.; Jeng, S.M. )

    1989-11-01

    A study of the interfacial reaction characteristics of SiC fiber-reinforced titanium aluminide and disordered titanium alloy composites has determined that the matrix alloy compositions affect the microstructure and the distribution of the reaction products, as well as the growth kinetics of the reaction zones. The interfacial reaction products in the ordered titanium aluminide composite are more complicated than those in the disordered titanium-alloy composite. The activation energy of the interfacial reaction in the ordered titanium aluminide composite is also higher than that in the disordered titanium alloy composite. Designing an optimum interface is necessary to enhance the reliability and service life at elevated temperatures. 16 refs.

  8. An Integrated Modular Avionics Development Environment

    NASA Astrophysics Data System (ADS)

    Schoofs, T.; Santos, S.; Tatibana, C.; Anjos, J.; Rufino, J.; Windsor, J.

    2009-05-01

    The ARINC 653 standard has taken a leading role within the aeronautical industry in the development of safety-critical systems based upon the Integrated Modular Avionics (IMA) concept. The related cost savings in reduced integration, verification and validation effort has raised interest in the European space industry for developing a spacecraft IMA approach and for the definition of an ARINC 653-for-Space software framework. As part of this process, it is necessary to establish an effective way to develop, test and analyse on-board applications without having access to the final IMA target platform for all engineers. Target platforms are usually extremely expensive considering hardware and software prices as well as training costs. This paper describes the architecture of an Integrated Modular Avionics Development Environment (IMADE) based on the Linux Operating System and the ARINC 653 simulator for Modular On-Board Applications that was developed by Skysoft Portugal, S.A. In cooperation with ESA, 2007-2008.

  9. A modular PMAD system for small spacecraft

    NASA Astrophysics Data System (ADS)

    Button, Robert M.

    1997-01-01

    Current trends in satellite design are focused on developing small, reliable, and inexpensive spacecraft. To that end, a modular power management and distribution system (PMAD) is proposed which will help transition the aerospace industry towards an assembly line approach to building spacecraft. The modular system is based on an innovative DC voltage boost converter called the Series Connected Boost Unit (SCBU). The SCBU uses existing DC-DC converters and adds a unique series connection. This simple modification provides the SCBU topology with many advantages over existing boost converters. Efficiencies of 94-98%, power densities above 1,000 We/kg, and inherent fault tolerance are just a few of the characteristics presented. Limitations of the SCBU technology are presented, and it is shown that the SCBU makes an ideal photovoltaic array regulator. A modular design based on the series connected boost unit is outlined and functional descriptions of the components are given.

  10. The gravity duals of modular Hamiltonians

    DOE PAGES

    Jafferis, Daniel L.; Suh, S. Josephine

    2016-09-12

    In this study, we investigate modular Hamiltonians defined with respect to arbitrary spatial regions in quantum field theory states which have semi-classical gravity duals. We find prescriptions in the gravity dual for calculating the action of the modular Hamiltonian on its defining state, including its dual metric, and also on small excitations around the state. Curiously, use of the covariant holographic entanglement entropy formula leads us to the conclusion that the modular Hamiltonian, which in the quantum field theory acts only in the causal completion of the region, does not commute with bulk operators whose entire gauge-invariant description is space-likemore » to the causal completion of the region.« less

  11. A Modular PMAD System for Small Spacecraft

    NASA Technical Reports Server (NTRS)

    Button, Robert M.

    1998-01-01

    Current trends in satellite design are focused on developing small, reliable, and inexpensive spacecraft. To that end, a modular power management and distribution system (PMAD) is proposed which will help transition the aerospace industry towards an assembly line approach to building spacecraft. The modular system is based on an innovative DC voltage boost converter called the Series Connected Boost Regulator (SCBR). The SCBR uses existing DC-DC converters and adds a unique series connection. This simple modification provides the SCBR topology with many advantages over existing boost converters. Efficiencies of 94-98%, power densities above 1,000 We/kg, and inherent fault tolerance are just a few of the characteristics presented. Limitations of the SCBR technology are presented, and it is shown that the SCBR makes an ideal photovoltaic array regulator. A modular design based on the series connected boost unit is outlined and functional descriptions of the components are given.

  12. Cell response of anodized nanotubes on titanium and titanium alloys.

    PubMed

    Minagar, Sepideh; Wang, James; Berndt, Christopher C; Ivanova, Elena P; Wen, Cuie

    2013-09-01

    Titanium and titanium alloy implants that have been demonstrated to be more biocompatible than other metallic implant materials, such as Co-Cr alloys and stainless steels, must also be accepted by bone cells, bonding with and growing on them to prevent loosening. Highly ordered nanoporous arrays of titanium dioxide that form on titanium surface by anodic oxidation are receiving increasing research interest due to their effectiveness in promoting osseointegration. The response of bone cells to implant materials depends on the topography, physicochemistry, mechanics, and electronics of the implant surface and this influences cell behavior, such as adhesion, proliferation, shape, migration, survival, and differentiation; for example the existing anions on the surface of a titanium implant make it negative and this affects the interaction with negative fibronectin (FN). Although optimal nanosize of reproducible titania nanotubes has not been reported due to different protocols used in studies, cell response was more sensitive to titania nanotubes with nanometer diameter and interspace. By annealing, amorphous TiO2 nanotubes change to a crystalline form and become more hydrophilic, resulting in an encouraging effect on cell behavior. The crystalline size and thickness of the bone-like apatite that forms on the titania nanotubes after implantation are also affected by the diameter and shape. This review describes how changes in nanotube morphologies, such as the tube diameter, the thickness of the nanotube layer, and the crystalline structure, influence the response of cells. Copyright © 2013 Wiley Periodicals, Inc.

  13. Titanium nanostructures for biomedical applications

    NASA Astrophysics Data System (ADS)

    Kulkarni, M.; Mazare, A.; Gongadze, E.; Perutkova, Š.; Kralj-Iglič, V.; Milošev, I.; Schmuki, P.; Iglič, A.; Mozetič, M.

    2015-02-01

    Titanium and titanium alloys exhibit a unique combination of strength and biocompatibility, which enables their use in medical applications and accounts for their extensive use as implant materials in the last 50 years. Currently, a large amount of research is being carried out in order to determine the optimal surface topography for use in bioapplications, and thus the emphasis is on nanotechnology for biomedical applications. It was recently shown that titanium implants with rough surface topography and free energy increase osteoblast adhesion, maturation and subsequent bone formation. Furthermore, the adhesion of different cell lines to the surface of titanium implants is influenced by the surface characteristics of titanium; namely topography, charge distribution and chemistry. The present review article focuses on the specific nanotopography of titanium, i.e. titanium dioxide (TiO2) nanotubes, using a simple electrochemical anodisation method of the metallic substrate and other processes such as the hydrothermal or sol-gel template. One key advantage of using TiO2 nanotubes in cell interactions is based on the fact that TiO2 nanotube morphology is correlated with cell adhesion, spreading, growth and differentiation of mesenchymal stem cells, which were shown to be maximally induced on smaller diameter nanotubes (15 nm), but hindered on larger diameter (100 nm) tubes, leading to cell death and apoptosis. Research has supported the significance of nanotopography (TiO2 nanotube diameter) in cell adhesion and cell growth, and suggests that the mechanics of focal adhesion formation are similar among different cell types. As such, the present review will focus on perhaps the most spectacular and surprising one-dimensional structures and their unique biomedical applications for increased osseointegration, protein interaction and antibacterial properties.

  14. Titanium nanostructures for biomedical applications.

    PubMed

    Kulkarni, M; Mazare, A; Gongadze, E; Perutkova, Š; Kralj-Iglič, V; Milošev, I; Schmuki, P; A Iglič; Mozetič, M

    2015-02-13

    Titanium and titanium alloys exhibit a unique combination of strength and biocompatibility, which enables their use in medical applications and accounts for their extensive use as implant materials in the last 50 years. Currently, a large amount of research is being carried out in order to determine the optimal surface topography for use in bioapplications, and thus the emphasis is on nanotechnology for biomedical applications. It was recently shown that titanium implants with rough surface topography and free energy increase osteoblast adhesion, maturation and subsequent bone formation. Furthermore, the adhesion of different cell lines to the surface of titanium implants is influenced by the surface characteristics of titanium; namely topography, charge distribution and chemistry. The present review article focuses on the specific nanotopography of titanium, i.e. titanium dioxide (TiO2) nanotubes, using a simple electrochemical anodisation method of the metallic substrate and other processes such as the hydrothermal or sol-gel template. One key advantage of using TiO2 nanotubes in cell interactions is based on the fact that TiO2 nanotube morphology is correlated with cell adhesion, spreading, growth and differentiation of mesenchymal stem cells, which were shown to be maximally induced on smaller diameter nanotubes (15 nm), but hindered on larger diameter (100 nm) tubes, leading to cell death and apoptosis. Research has supported the significance of nanotopography (TiO2 nanotube diameter) in cell adhesion and cell growth, and suggests that the mechanics of focal adhesion formation are similar among different cell types. As such, the present review will focus on perhaps the most spectacular and surprising one-dimensional structures and their unique biomedical applications for increased osseointegration, protein interaction and antibacterial properties.

  15. Dynamics of overlapping structures in modular networks.

    PubMed

    Almendral, J A; Leyva, I; Li, D; Sendiña-Nadal, I; Havlin, S; Boccaletti, S

    2010-07-01

    Modularity is a fundamental feature of real networks, being intimately bounded to their functionality, i.e., to their capability of performing parallel tasks in a coordinated way. Although the modular structure of real graphs has been intensively studied, very little is known on the interactions between functional modules of a graph. Here, we present a general method based on synchronization of networking oscillators, that is able to detect overlapping structures in multimodular environments. We furthermore report the full analytical and theoretical description on the relationship between the overlapping dynamics and the underlying network topology. The method is illustrated by means of a series of applications.

  16. [Modular tumor prostheses of the humerus].

    PubMed

    Funovics, P T; Dominkus, M

    2010-10-01

    The humerus is a common location of musculoskeletal tumors. Modular prostheses of the humerus, besides APC and biological reconstructions, allow restoration of resulting bone defects. The functional outcome is determined by the extent of bone and soft tissue loss. Anatomical shoulder prostheses have a limited abductor function, while shoulder function could be improved by an inverse prosthetic design and implants for ligament repair. Elbow prostheses provide satisfactory function. Our own results in 101 patients showed a 23% revision rate. The median overall survival was 171 months with an overall 5-year survival of 53%. With respect to good oncological outcomes modular reconstruction of the humerus is a feasible treatment option for cancer patients.

  17. Modular arrangement of regulatory RNA elements.

    PubMed

    Roßmanith, Johanna; Narberhaus, Franz

    2017-03-04

    Due to their simple architecture and control mechanism, regulatory RNA modules are attractive building blocks in synthetic biology. This is especially true for riboswitches, which are natural ligand-binding regulators of gene expression. The discovery of various tandem riboswitches inspired the design of combined RNA modules with activities not yet found in nature. Riboswitches were placed in tandem or in combination with a ribozyme or temperature-responsive RNA thermometer resulting in new functionalities. Here, we compare natural examples of tandem riboswitches with recently designed artificial RNA regulators suggesting substantial modularity of regulatory RNA elements. Challenges associated with modular RNA design are discussed.

  18. Proving relations between modular graph functions

    NASA Astrophysics Data System (ADS)

    Basu, Anirban

    2016-12-01

    We consider modular graph functions that arise in the low energy expansion of the four graviton amplitude in type II string theory. The vertices of these graphs are the positions of insertions of vertex operators on the toroidal worldsheet, while the links are the scalar Green functions connecting the vertices. Graphs with four and five links satisfy several non-trivial relations, which have been proved recently. We prove these relations by using elementary properties of Green functions and the details of the graphs. We also prove a relation between modular graph functions with six links.

  19. Modular arrangement of regulatory RNA elements

    PubMed Central

    Roßmanith, Johanna; Narberhaus, Franz

    2017-01-01

    ABSTRACT Due to their simple architecture and control mechanism, regulatory RNA modules are attractive building blocks in synthetic biology. This is especially true for riboswitches, which are natural ligand-binding regulators of gene expression. The discovery of various tandem riboswitches inspired the design of combined RNA modules with activities not yet found in nature. Riboswitches were placed in tandem or in combination with a ribozyme or temperature-responsive RNA thermometer resulting in new functionalities. Here, we compare natural examples of tandem riboswitches with recently designed artificial RNA regulators suggesting substantial modularity of regulatory RNA elements. Challenges associated with modular RNA design are discussed. PMID:28010165

  20. Plasma quench production of titanium from titanium tetrachloride

    SciTech Connect

    Sears, J.W.

    1994-10-01

    This project, Plasma Quench Production of Titanium from Titanium Tetrachloride, centers on developing a technique for rapidly quenching the high temperature metal species and preventing back reactions with the halide. The quenching technique chosen uses the temperature drop produced in a converging/diverging supersonic nozzle. The rapid quench provided by this nozzle prevents the back reaction of the halide and metal. The nature of the process produces nanosized particles (10 to 100 nm). The powders are collected by cyclone separators, the hydrogen flared, and the acid scrubbed. Aluminum and titanium powders have been produced in the laboratory-scale device at 1 gram per hour. Efforts to date to scale up this process have not been successful.

  1. Titanium diaphragm makes excellent amplitron cathode support

    NASA Technical Reports Server (NTRS)

    Teich, W. W.

    1965-01-01

    Cathode support structure designed around a titanium diaphragm prevents radial misalignment between the cathode and anode in amplitrons. The titanium exhibits low thermal conductivity, tolerates lateral thermal expansion of the cathode, and is a poor primary and secondary emission medium.

  2. Method for Surface Texturing Titanium Products

    NASA Technical Reports Server (NTRS)

    Banks, Bruce A. (Inventor)

    1998-01-01

    The present invention teaches a method of producing a textured surface upon an arbitrarily configured titanium or titanium alloy object for the purpose of improving bonding between the object and other materials such as polymer matrix composites and/or human bone for the direct in-growth of orthopaedic implants. The titanium or titanium alloy object is placed in an electrolytic cell having an ultrasonically agitated solution of sodium chloride therein whereby a pattern of uniform "pock mark" like pores or cavities are produced upon the object's surface. The process is very cost effective compared to other methods of producing rough surfaces on titanium and titanium alloy components. The surface textures produced by the present invention are etched directly into the parent metal at discrete sites separated by areas unaffected by the etching process. Bonding materials to such surface textures on titanium or titanium alloy can thus support a shear load even if adhesion of the bonding material is poor.

  3. Titanium pigmentation. An electron probe microanalysis study

    SciTech Connect

    Dupre, A.; Touron, P.; Daste, J.; Lassere, J.; Bonafe, J.L.; Viraben, R.

    1985-05-01

    A patient had an unusual pigmentary disease induced by titanium dioxide. The use of a topical cream containing titanium dioxide caused a xanthomalike appearance on the patient's penis. Electron probe microanalysis was valuable in establishing the cause of this balanitis.

  4. Modular Apparatus and Method for Attaching Multiple Devices

    NASA Technical Reports Server (NTRS)

    Okojie, Robert S (Inventor)

    2015-01-01

    A modular apparatus for attaching sensors and electronics is disclosed. The modular apparatus includes a square recess including a plurality of cavities and a reference cavity such that a pressure sensor can be connected to the modular apparatus. The modular apparatus also includes at least one voltage input hole and at least one voltage output hole operably connected to each of the plurality of cavities such that voltage can be applied to the pressure sensor and received from the pressure sensor.

  5. The oxidation of titanium silicide

    NASA Astrophysics Data System (ADS)

    Sandwick, Thom; Rajan, Krishna

    1990-11-01

    This paper investigates the morphology changes that occur with the oxidation of a ti-tanium silicide—polysilicon system. These changes were studied as a function of poly-silicon doping and silicide formation parameters. Emphasis was placed on transmission electron microscopy studies of the samples by planar and cross sectional techniques. Various surface analysis methods have also been used to characterize the films. This study helps to define the possible use and shortcomings of a self aligned titanium silicide insulator. The results show that varying quality insulators result, dependent largely on the initial conditions of the titanium silicide. After oxidation the Auger and TEM anal-ysis show that in all cases some form of silicon dioxide was created, but typically a considerable amount of titanium oxide was also present. For instance, it was apparent that more titanium oxide formed on the samples RTA’ed for 1 min at 700° C than the 5 min at 800° C and considerably more on the arsenic doped sample than the boron doped. The silicide also had morphology changes as the result of the oxidation. There was a phase change from the C49 to C54 phase for the 1 min at 700° C samples as would be expected at the time and temperature of the oxidation. There also was a sig-nificant amount of agglomeration and epitaxial growth observed. Further work is re-quired to completely characterize these phenomena.

  6. Lightweight Protective Coatings For Titanium Alloys

    NASA Technical Reports Server (NTRS)

    Wiedemann, Karl E.; Taylor, Patrick J.; Clark, Ronald K.

    1992-01-01

    Lightweight coating developed to protect titanium and titanium aluminide alloys and titanium-matrix composite materials from attack by environment when used at high temperatures. Applied by sol-gel methods, and thickness less than 5 micrometers. Reaction-barrier and self-healing diffusion-barrier layers combine to protect titanium alloy against chemical attack by oxygen and nitrogen at high temperatures with very promising results. Can be extended to protection of other environmentally sensitive materials.

  7. Experimental titanium alloys for dental applications.

    PubMed

    Faria, Adriana C L; Rodrigues, Renata C S; Rosa, Adalberto L; Ribeiro, Ricardo F

    2014-12-01

    Although the use of titanium has increased, casting difficulties limit routine use. The purpose of the present study was to compare the mechanical properties and biocompatibility of the experimental titanium alloys titanium-5-zirconium, titanium-5-tantalum, and titanium-5-tantalum-5-zirconium (in wt%) with those of commercially pure titanium. Specimens of titanium alloys and commercially pure titanium were cast by using plasma. Their modulus of elasticity and ultimate tensile strength were determined in a universal testing machine. Biocompatibility was evaluated with SCC9 cells. In periods of 1, 4, 7, 10, and 14 days, cell proliferation was evaluated by the (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) tetrazolium reduction assay, and cell viability was evaluated in the 7-day period. Cell morphology was evaluated at 2, 12, and 24 hours. Modulus of elasticity, ultimate tensile strength, and cell viability were analyzed by 1-way ANOVA and the Bonferroni test; cell proliferation data were compared by 2-way ANOVA (alloy versus time) and by the Bonferroni test; and the cell morphology data were analyzed by split-plot design. All statistical tests were performed at the 95% confidence level (P<.05). Titanium-5-tantalum presented the lowest modulus of elasticity and ultimate tensile strength, whereas titanium-5-zirconium and titanium-5-tantalum-5-zirconium were statistically similar to commercially pure titanium. Cell proliferation and viability were not affected by any alloy being similar to those observed for commercially pure titanium. No noticeably differences were found in the morphology of cells cultured on any alloy and commercially pure titanium. Experimental alloys, especially titanium-5-zirconium and titanium-5-tantalum-5-zirconium, presented promising mechanical results for future studies and clinical applications. In addition, these alloys, evaluated by cell proliferation, viability, and morphology, were found to be biocompatible in vitro

  8. Lightweight Protective Coatings For Titanium Alloys

    NASA Technical Reports Server (NTRS)

    Wiedemann, Karl E.; Taylor, Patrick J.; Clark, Ronald K.

    1992-01-01

    Lightweight coating developed to protect titanium and titanium aluminide alloys and titanium-matrix composite materials from attack by environment when used at high temperatures. Applied by sol-gel methods, and thickness less than 5 micrometers. Reaction-barrier and self-healing diffusion-barrier layers combine to protect titanium alloy against chemical attack by oxygen and nitrogen at high temperatures with very promising results. Can be extended to protection of other environmentally sensitive materials.

  9. Development of Lightweight Titanium Base Alloys

    DTIC Science & Technology

    1989-04-15

    program on Development of Lightweight Titanium Base Alloys was to develop new titanium alloys with 10% lower density, 50% higher elastic modulus, and...program. permitted the cvaluation of a low-dc-isity. dislicrsion-strengthcnicd 02 + y titanium aluminide , which has excellent high temperature strength...713e alloy has significantly higher strength than the titanium aluminides . The limited data for ’i-34AI-4Be show it to be very strong above 7(X)°C

  10. Process for reproducibly preparing titanium subhydride

    DOEpatents

    Carlson, Richard S.

    1982-01-01

    Titanium subhydride is produced in a reactor by heating a selected amount of finely divided titanium compound at a selected temperature for a selected period of time under dynamic vacuum conditions. Hydrogen is removed substantially uniformly from each powder grain and there is produced a subhydride of substantially uniform titanium-hydrogen composition. Selection of the amount, temperature and time produces a subhydride of selected titanium-hydrogen composition.

  11. 46 CFR 181.450 - Independent modular smoke detecting units.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Independent modular smoke detecting units. 181.450... Independent modular smoke detecting units. (a) An independent modular smoke detecting unit must: (1) Meet UL 217 (incorporated by reference, see 46 CFR 175.600) and be listed as a “Single Station Smoke detector...

  12. 46 CFR 181.450 - Independent modular smoke detecting units.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Independent modular smoke detecting units. 181.450... Independent modular smoke detecting units. (a) An independent modular smoke detecting unit must: (1) Meet UL 217 (incorporated by reference, see 46 CFR 175.600) and be listed as a “Single Station Smoke detector...

  13. 46 CFR 181.450 - Independent modular smoke detecting units.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Independent modular smoke detecting units. 181.450... Independent modular smoke detecting units. (a) An independent modular smoke detecting unit must: (1) Meet UL 217 (incorporated by reference, see 46 CFR 175.600) and be listed as a “Single Station Smoke...

  14. 46 CFR 181.450 - Independent modular smoke detecting units.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Independent modular smoke detecting units. 181.450... Independent modular smoke detecting units. (a) An independent modular smoke detecting unit must: (1) Meet UL 217 (incorporated by reference, see 46 CFR 175.600) and be listed as a “Single Station Smoke...

  15. 46 CFR 181.450 - Independent modular smoke detecting units.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Independent modular smoke detecting units. 181.450... Independent modular smoke detecting units. (a) An independent modular smoke detecting unit must: (1) Meet UL 217 (incorporated by reference, see 46 CFR 175.600) and be listed as a “Single Station Smoke...

  16. On Classification of Modular Categories by Rank: Table A.1

    SciTech Connect

    Bruillard, Paul; Ng, Siu-Hung; Rowell, Eric C.; Wang, Zhenghan

    2016-04-10

    The feasibility of a classification-by-rank program for modular categories follows from the Rank-Finiteness Theorem. We develop arithmetic, representation theoretic and algebraic methods for classifying modular categories by rank. As an application, we determine all possible fusion rules for all rank=5 modular categories and describe the corresponding monoidal equivalence classes.

  17. Yttria Nanoparticle Reinforced Commercially Pure (CP) Titanium

    DTIC Science & Technology

    2011-09-01

    nanoparticles as well as titanium boride (TiB) reinforcements were produced through gas atomization. After consolidation and extrusion, room temperature...pure FE iron O oxygen Ti titanium TiB titanium boride TYS tensile yield strength UTS ultimate tensile strength wt% weight percent Y2O3

  18. 40 CFR 180.1195 - Titanium dioxide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Titanium dioxide. 180.1195 Section 180.1195 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS... Titanium dioxide. Titanium dioxide (CAS Reg. No. 13463-67-7) is exempted from the requirement of...

  19. 21 CFR 73.3126 - Titanium dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Titanium dioxide. 73.3126 Section 73.3126 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Medical Devices § 73.3126 Titanium dioxide. (a) Identity and specifications. The color additive titanium dioxide (CAS Reg. No. 13463-67-7), Color Index No. 77891,...

  20. 21 CFR 73.1575 - Titanium dioxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Titanium dioxide. 73.1575 Section 73.1575 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1575 Titanium dioxide. (a) Identity and specifications. (1) The color additive titanium dioxide shall conform in identity and specifications to the...

  1. 21 CFR 73.1575 - Titanium dioxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Titanium dioxide. 73.1575 Section 73.1575 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1575 Titanium dioxide. (a) Identity and specifications. (1) The color additive titanium dioxide shall conform in identity and specifications to the...

  2. 40 CFR 180.1195 - Titanium dioxide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Titanium dioxide. 180.1195 Section 180.1195 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS... Titanium dioxide. Titanium dioxide is exempted from the requirement of a tolerance for residues in or...

  3. 21 CFR 73.1575 - Titanium dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Titanium dioxide. 73.1575 Section 73.1575 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1575 Titanium dioxide. (a) Identity and specifications. (1) The color additive titanium dioxide shall conform in identity and specifications to the...

  4. 40 CFR 180.1195 - Titanium dioxide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Titanium dioxide. 180.1195 Section 180.1195 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS... Titanium dioxide. Titanium dioxide (CAS Reg. No. 13463-67-7) is exempted from the requirement of...

  5. 21 CFR 73.3126 - Titanium dioxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Titanium dioxide. 73.3126 Section 73.3126 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Medical Devices § 73.3126 Titanium dioxide. (a) Identity and specifications. The color additive titanium dioxide (CAS Reg. No. 13463-67-7), Color Index No. 77891,...

  6. 40 CFR 180.1195 - Titanium dioxide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Titanium dioxide. 180.1195 Section 180.1195 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS... Titanium dioxide. Titanium dioxide is exempted from the requirement of a tolerance for residues in or...

  7. 40 CFR 180.1195 - Titanium dioxide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Titanium dioxide. 180.1195 Section 180.1195 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS... Titanium dioxide. Titanium dioxide is exempted from the requirement of a tolerance for residues in or...

  8. 21 CFR 73.3126 - Titanium dioxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Titanium dioxide. 73.3126 Section 73.3126 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Medical Devices § 73.3126 Titanium dioxide. (a) Identity and specifications. The color additive titanium dioxide (CAS Reg. No. 13463-67-7), Color Index No. 77891,...

  9. Honeywell Modular Automation System Computer Software Documentation

    SciTech Connect

    CUNNINGHAM, L.T.

    1999-09-27

    This document provides a Computer Software Documentation for a new Honeywell Modular Automation System (MAS) being installed in the Plutonium Finishing Plant (PFP). This system will be used to control new thermal stabilization furnaces in HA-211 and vertical denitration calciner in HC-230C-2.

  10. Modularity, Working Memory and Language Acquisition

    ERIC Educational Resources Information Center

    Baddeley, Alan D.

    2017-01-01

    The concept of modularity is used to contrast the approach to working memory proposed by Truscott with the Baddeley and Hitch multicomponent model. This proposes four sub components comprising the "central executive," an executive control system of limited attentional capacity that utilises storage based on separate but interlinked…

  11. Modular learning models in forecasting natural phenomena.

    PubMed

    Solomatine, D P; Siek, M B

    2006-03-01

    Modular model is a particular type of committee machine and is comprised of a set of specialized (local) models each of which is responsible for a particular region of the input space, and may be trained on a subset of training set. Many algorithms for allocating such regions to local models typically do this in automatic fashion. In forecasting natural processes, however, domain experts want to bring in more knowledge into such allocation, and to have certain control over the choice of models. This paper presents a number of approaches to building modular models based on various types of splits of training set and combining the models' outputs (hard splits, statistically and deterministically driven soft combinations of models, 'fuzzy committees', etc.). An issue of including a domain expert into the modeling process is also discussed, and new algorithms in the class of model trees (piece-wise linear modular regression models) are presented. Comparison of the algorithms based on modular local modeling to the more traditional 'global' learning models on a number of benchmark tests and river flow forecasting problems shows their higher accuracy and transparency of the resulting models.

  12. Modular Building Institute 2001 Educational Showcase.

    ERIC Educational Resources Information Center

    Modular Building Inst., Charlottesville, VA.

    This publication contains brief articles concerned with modular school structures. Some articles offer examples of such structures at actual schools. The articles in this issue are: (1) "An Architect's Perspective: Convincing a Skeptic" (Robert M. Iamello); (2) "66 Portables for San Mateo High" (Steven Williams); (3) "Case Study: Charter Schools"…

  13. Modular Infrastructure for Rapid Flight Software Development

    NASA Technical Reports Server (NTRS)

    Pires, Craig

    2010-01-01

    This slide presentation reviews the use of modular infrastructure to assist in the development of flight software. A feature of this program is the use of model based approach for application unique software. A review of two programs that this approach was use on are: the development of software for Hover Test Vehicle (HTV), and Lunar Atmosphere and Dust Environment Experiment (LADEE).

  14. Modular evolution of the Cetacean vertebral column.

    PubMed

    Buchholtz, Emily A

    2007-01-01

    Modular theory predicts that hierarchical developmental processes generate hierarchical phenotypic units that are capable of independent modification. The vertebral column is an overtly modular structure, and its rapid phenotypic transformation in cetacean evolution provides a case study for modularity. Terrestrial mammals have five morphologically discrete vertebral series that are now known to be coincident with Hox gene expression patterns. Here, I present the hypothesis that in living Carnivora and Artiodactyla, and by inference in the terrestrial ancestors of whales, the series are themselves components of larger precaudal and caudal modular units. Column morphology in a series of fossil and living whales is used to predict the type and sequence of developmental changes responsible for modification of that ancestral pattern. Developmental innovations inferred include independent meristic additions to the precaudal column in basal archaeocetes and basilosaurids, stepwise homeotic reduction of the sacral series in protocetids, and dissociation of the caudal series into anterior tail and fluke subunits in basilosaurids. The most dramatic change was the novel association of lumbar and anterior caudal vertebrae in a module that crosses the precaudal/caudal boundary. This large unit is defined by shared patterns of vertebral morphology, count, and size in all living whales (Neoceti).

  15. Design of a modular digital computer system

    NASA Technical Reports Server (NTRS)

    1973-01-01

    A design tradeoff study is reported for a modular spaceborne computer system that is responsive to many mission types and phases. The computer uses redundancy to maximize reliability, and multiprocessing to maximize processing capacity. Fault detection and recovery features provide optimal reliability.

  16. Written Reformulation in a Modular Approach.

    ERIC Educational Resources Information Center

    Flottum, Kjersti

    1996-01-01

    Examines the relationship between form and use of the reformulation sequence signalled by "c'est-a-dire" in written French and describes this sequence's various functions. The article attempts to show how a modular approach consisting of structural, semantic, pragmatic, and textual components contributes to a new and accurate description of…

  17. Modular microfluidic system for biological sample preparation

    DOEpatents

    Rose, Klint A.; Mariella, Jr., Raymond P.; Bailey, Christopher G.; Ness, Kevin Dean

    2015-09-29

    A reconfigurable modular microfluidic system for preparation of a biological sample including a series of reconfigurable modules for automated sample preparation adapted to selectively include a) a microfluidic acoustic focusing filter module, b) a dielectrophoresis bacteria filter module, c) a dielectrophoresis virus filter module, d) an isotachophoresis nucleic acid filter module, e) a lyses module, and f) an isotachophoresis-based nucleic acid filter.

  18. Modular Building Institute 1999 Educational Showcase.

    ERIC Educational Resources Information Center

    Modular Building Inst., Charlottesville, VA.

    This publication contains brief articles concerned with modular school structures. Many articles offer examples of such structures at actual schools. The articles in this issue are: (1) "Hightstown High School"; (2) "St. Pius X Parish, Vancouver BC"; (3) "Forrest Street Elementary School"; (4) "Kingman Academy of Learning"; (5) "Women Christian…

  19. The Modular Market. Studies in Further Education.

    ERIC Educational Resources Information Center

    Theodossin, Ernest

    Origins of modular courses and the module in British postcompulsory education are considered, along with characteristics of modules, credit transfer, five case studies, and marketing in further and higher education. A module is a measured part (or course) of an extended learning experience that leads to specified qualifications. A designated…

  20. Transforming modular classrooms in California and elsewhere

    SciTech Connect

    Eilert, P.L.; Hoeschele, M.

    1998-07-01

    This paper discussed a market-transformation program to reduce energy use in modular school classrooms, a large part of new construction activities in California's schools. Today's modular classrooms cost more to operate than is necessary to provide effective, comfortable learning conditions for students and teachers. Although past resource acquisition programs have created a demand for efficient products and services, modular classrooms remain poorly differentiated in this respect. The cost-effectiveness of a range of potential energy efficiency measures (EEM's) were evaluated including lighting, alternative HVAC options, and improved envelope features. Viable EEM's were combined in two separate packages. The first includes measures that can easily be implemented and are projected to reduce operating costs by 30%. The second implements a daylighting system, a two-stage evaporative cooler, and radiant heating, resulting in projected annual energy cost savings over 60%. Transforming the market for modular classrooms is accomplished using natural market forces, rather than financial incentives directed at an entire industry. Proactive efforts are focused on the manufacturing industry's change leaders to commercialize energy-efficient products. Lost market share and peer pressure do the heavy lifting of convincing market followers to upgrade their products. Demand for efficient classrooms is increased by educating schools about the new products' financial advantages, comfort enhancements, and environmental benefits. As new products become established in the marketplace, support will be gradually withdrawn. The relevance of this work extends beyond California, given other States' programs to reduce class size, and the Presidents initiative to reduce class size nationally.

  1. Modular Building Institute 2002 Educational Showcase.

    ERIC Educational Resources Information Center

    Modular Building Inst., Charlottesville, VA.

    This publication contains brief articles concerned with modular school structures. Some articles offer examples of such structures at actual schools. The articles in this issue are: (1) "Re-Educating Schools" (Chuck Savage); (2) "Tax-Exempt Financing for Public Schools" (John Kennedy); (3) "Help Us Rebuild America" (Michael Roman); (4) "Case…

  2. A Modular Curriculum in Information Studies.

    ERIC Educational Resources Information Center

    Large, J. A.

    Prepared under a contract between UNESCO and IFLA (the International Federation of Library Associations), this modular curriculum is intended as a resource from which curricula can be constructed by individual departments of information studies to meet local needs and circumstances. Following an introductory discussion and explanation of the…

  3. Modular space station phase B extension

    NASA Technical Reports Server (NTRS)

    1971-01-01

    The system safety analyses and requirements developed for the modular space station during the phase B extension are reviewed. Residual hazards and unresolved safety issues are summarized. Hazards resulting from equipment failures or malfunctions, operations, or credible accidents are identified and evaluated. Special safety trade studies are presented.

  4. GAMBIT: Global And Modular BSM Inference Tool

    NASA Astrophysics Data System (ADS)

    GAMBIT Collaboration; Athron, Peter; Balazs, Csaba; Bringmann, Torsten; Buckley, Andy; Chrzä Szcz, Marcin; Conrad, Jan; Cornell, Jonathan M.; Dal, Lars A.; Dickinson, Hugh; Edsjö, Joakim; Farmer, Ben; Jackson, Paul; Krislock, Abram; Kvellestad, Anders; Lundberg, Johan; McKay, James; Mahmoudi, Farvah; Martinez, Gregory D.; Putze, Antje Raklev, Are; Ripken, Joachim; Rogan, Christopher; Saavedra, Aldo; Savage, Christopher; Scott, Pat; Seo, Seon-Hee; Serra, Nicola; Weniger, Christoph; White, Martin; Wild, Sebastian

    2017-08-01

    GAMBIT (Global And Modular BSM Inference Tool) performs statistical global fits of generic physics models using a wide range of particle physics and astrophysics data. Modules provide native simulations of collider and astrophysics experiments, a flexible system for interfacing external codes (the backend system), a fully featured statistical and parameter scanning framework, and additional tools for implementing and using hierarchical models.

  5. Modular processes in mind and brain.

    PubMed

    Sternberg, Saul

    2011-05-01

    One approach to understanding a complex process starts with an attempt to divide it into modules·, sub-processes that are independent in some sense, and have distinct functions. In this paper, I discuss an approach to the modular decomposition of neural and mental processes. Several examples of process decomposition are presented, together with discussion of inferential requirements. Two examples are of well-established and purely behavioural realizations of the approach (signal detection theory applied to discrimination data; the method of additive factors applied to reaction-time data), and lead to the identification of mental modules. Other examples, leading to the identification of modular neural processes, use brain measures, including the fMRI signal, the latencies of electrophysiological events, and their amplitudes. Some measures are pure (reflecting just one process), while others are composite. Two of the examples reveal mental and neural modules that correspond. Attempts to associate brain regions with behaviourally defined processing modules that use a brain manipulation (transcranial magnetic stimulation, TMS) are promising but incomplete. I show why the process-decomposition approach discussed here, in which the criterion for modularity is separate modifiability, is superior for modular decomposition to the more frequently used task comparison procedure (often used in cognitive neuropsychology) and to its associated subtraction method. To demonstrate the limitations of task comparison, I describe the erroneous conclusion to which it has led about sleep deprivation, and the interpretive difficulties in a TMS study.

  6. Consciousness in SLA: A Modular Perspective

    ERIC Educational Resources Information Center

    Truscott, John

    2015-01-01

    Understanding the place of consciousness in second language acquisition (SLA) is crucial for an understanding of how acquisition occurs. Considerable work has been done on this topic, but nearly all of it assumes a highly non-modular view, according to which language and its development is "nothing special". As this assumption runs…

  7. Modular polynomial arithmetic in partial fraction decomposition

    NASA Technical Reports Server (NTRS)

    Abdali, S. K.; Caviness, B. F.; Pridor, A.

    1977-01-01

    Algorithms for general partial fraction decomposition are obtained by using modular polynomial arithmetic. An algorithm is presented to compute inverses modulo a power of a polynomial in terms of inverses modulo that polynomial. This algorithm is used to make an improvement in the Kung-Tong partial fraction decomposition algorithm.

  8. Modular arithmetic weight and cyclic shifting.

    NASA Technical Reports Server (NTRS)

    Hartman, W. F.

    1972-01-01

    This note shows that the modular arithmetic weight of an integer is invariant to the cyclic shifts of its radix-2 form. This result leads to a reduced search for the minimum weight codeword in a cyclic AN-code as well as to a better understanding of previous work.

  9. A Modular, Reconfigurable Surveillance UAV Architecture

    DTIC Science & Technology

    2007-11-02

    Una Società Galileo Avionica A Modular, Reconfigurable Surveillance UAV Architecture METEOR, Finmeccanica Group Zona Industriale di Soleschiano Via...ES) METEOR, Finmeccanica Group Zona Industriale di Soleschiano Via Mario Stoppani 21 34077 Ronchi dei Legionari (GO) ITALY 8. PERFORMING

  10. What Symbionts Teach us about Modularity

    PubMed Central

    Porcar, Manuel; Latorre, Amparo; Moya, Andrés

    2013-01-01

    The main goal of Synthetic Biology (SB) is to apply engineering principles to biotechnology in order to make life easier to engineer. These engineering principles include modularity: decoupling of complex systems into smaller, orthogonal sub-systems that can be used in a range of different applications. The successful use of modules in engineering is expected to be reproduced in synthetic biological systems. But the difficulties experienced up to date with SB approaches question the short-term feasibility of designing life. Considering the “engineerable” nature of life, here we discuss the existence of modularity in natural living systems, particularly in symbiotic interactions, and compare the behavior of such systems, with those of engineered modules. We conclude that not only is modularity present but it is also common among living structures, and that symbioses are a new example of module-like sub-systems having high similarity with modularly designed ones. However, we also detect and stress fundamental differences between man-made and biological modules. Both similarities and differences should be taken into account in order to adapt SB design to biological laws. PMID:25023877

  11. Consciousness in SLA: A Modular Perspective

    ERIC Educational Resources Information Center

    Truscott, John

    2015-01-01

    Understanding the place of consciousness in second language acquisition (SLA) is crucial for an understanding of how acquisition occurs. Considerable work has been done on this topic, but nearly all of it assumes a highly non-modular view, according to which language and its development is "nothing special". As this assumption runs…

  12. Design of a modular digital computer system

    NASA Technical Reports Server (NTRS)

    1980-01-01

    A Central Control Element (CCE) module which controls the Automatically Reconfigurable Modular System (ARMS) and allows both redundant processing and multi-computing in the same computer with real time mode switching, is discussed. The same hardware is used for either reliability enhancement, speed enhancement, or for a combination of both.

  13. Modular design for a liquid target

    NASA Astrophysics Data System (ADS)

    Li, K.; Jahangiri, P.; Zacchia, N.; Uittenbosch, T.; Buckley, K.; Martinez, D. M.; Hoehr, C.

    2017-05-01

    A modular target with varying depth has been designed and built to investigate density reduction in liquid targets. An interchangeable middle piece allows target depths from 7.5 to 52.5 mm. The target has been tested and found to be leak tight and functional.

  14. Titanium matrix composites: Mechanical behavior

    SciTech Connect

    Mall, S.; Nicholas, T.

    1997-12-31

    Because of their unique mix of properties and behavior in high-performance applications, Titanium Matrix Composites are presently the focus of special research and development activity. This new book presents a review of current technology on the mechanical behavior of these materials. Each chapter was prepared specifically for this new book by one or more specialists in this subject. This book is divided into the following chapters: (1) Introduction; (2) Monotonic Response; (3) Micromechanical Theories for Inelastic Fibrous Composite Materials; (4) Interfaces in Metal Matrix Composites; (5) Fatigue Failure Mechanisms in TMCs; (6) Fatigue and Thermomechanical Fatigue Life Prediction; (7) Creep Behavior of Fiber Reinforced Titanium Matrix Composites; (8) Fatigue Crack Growth; (9) Notch Strength of Titanium Matrix Composites; and (10) Micromechanical Analysis and Modeling.

  15. Photonuclear reactions on titanium isotopes

    SciTech Connect

    Belyshev, S. S.; Dzhilavyan, L. Z.; Ishkhanov, B. S.; Kapitonov, I. M.; Kuznetsov, A. A. Orlin, V. N.; Stopani, K. A.

    2015-03-15

    The photodisintegration of titanium isotopes in the giant-dipole-resonance energy region is studied by the photon-activation method. Bremsstrahlung photons whose spectrum has the endpoint energy of 55 MeV is used. The yields and integrated cross sections are determined for photoproton reactions on the titanium isotopes {sup 47,48,49,50}Ti. The respective experimental results are compared with their counterparts calculated on the basis of the TALYS code and a combined photonucleon-reaction model. The TALYS code disregards the isospin structure of the giant dipole resonance and is therefore unable to describe the yield of photoproton reactions on the heavy titanium isotopes {sup 49,50}Ti.

  16. Adaptive mesh refinement in titanium

    SciTech Connect

    Colella, Phillip; Wen, Tong

    2005-01-21

    In this paper, we evaluate Titanium's usability as a high-level parallel programming language through a case study, where we implement a subset of Chombo's functionality in Titanium. Chombo is a software package applying the Adaptive Mesh Refinement methodology to numerical Partial Differential Equations at the production level. In Chombo, the library approach is used to parallel programming (C++ and Fortran, with MPI), whereas Titanium is a Java dialect designed for high-performance scientific computing. The performance of our implementation is studied and compared with that of Chombo in solving Poisson's equation based on two grid configurations from a real application. Also provided are the counts of lines of code from both sides.

  17. Logarithmic conformal field theory, log-modular tensor categories and modular forms

    NASA Astrophysics Data System (ADS)

    Creutzig, Thomas; Gannon, Terry

    2017-10-01

    The two pillars of rational conformal field theory and rational vertex operator algebras are modularity of characters, and the interpretation of its category of modules as a modular tensor category. Overarching these pillars is the Verlinde formula. In this paper we consider the more general class of logarithmic conformal field theories and C 2-cofinite vertex operator algebras. We suggest logarithmic variants of those pillars and of Verlinde’s formula. We illustrate our ideas with the \

  18. Modularity for Motor Control and Motor Learning.

    PubMed

    d'Avella, Andrea

    2016-01-01

    How the central nervous system (CNS) overcomes the complexity of multi-joint and multi-muscle control and how it acquires or adapts motor skills are fundamental and open questions in neuroscience. A modular architecture may simplify control by embedding features of both the dynamic behavior of the musculoskeletal system and of the task into a small number of modules and by directly mapping task goals into module combination parameters. Several studies of the electromyographic (EMG) activity recorded from many muscles during the performance of different tasks have shown that motor commands are generated by the combination of a small number of muscle synergies, coordinated recruitment of groups of muscles with specific amplitude balances or activation waveforms, thus supporting a modular organization of motor control. Modularity may also help understanding motor learning. In a modular architecture, acquisition of a new motor skill or adaptation of an existing skill after a perturbation may occur at the level of modules or at the level of module combinations. As learning or adapting an existing skill through recombination of modules is likely faster than learning or adapting a skill by acquiring new modules, compatibility with the modules predicts learning difficulty. A recent study in which human subjects used myoelectric control to move a mass in a virtual environment has tested this prediction. By altering the mapping between recorded muscle activity and simulated force applied on the mass, as in a complex surgical rearrangement of the tendons, it has been possible to show that it is easier to adapt to a perturbation that is compatible with the muscle synergies used to generate hand force than to a similar but incompatible perturbation. This result provides direct support for a modular organization of motor control and motor learning.

  19. Submerged Arc Welding of Titanium.

    DTIC Science & Technology

    1978-09-30

    AD-AOB5 400 MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF MATERIA -ETC F/G 11/6 SUBMERGED ARC WELDING OF TITANIUM.(U) UCSEP 18 G HUNTER, 6 B KENNEY, M...3. RECIPIENT’S CATALOG NUMW-- TITLE (and Subtitle) n or QnQMED Submerged Arc Welding of Tianu Technal epor o. 9? ji’ G./ Huntert’G. KenneybM Ring...nuinbor) Welding , Titanium, Fluxes, Oxygen, Nitrogen ASS40qAfC ,,(AA.K 20. A9 AT(Continue an revereet side It necessay and Identify by block numabor) 0

  20. Thermal Stir Welds in Titanium

    NASA Astrophysics Data System (ADS)

    Fonda, Richard W.; Knipling, Keith E.; Pilchak, Adam L.

    2016-01-01

    Although conventional friction stir welding (FSW) has proven unsuccessful in joining thick sections of alpha and near-alpha titanium alloys, thermal stir welding, a variant of the FSW process in which an external heat source is used to preheat the workpiece, is demonstrated to be able to reliably join 12.3-mm-thick plates of CP titanium. This paper describes the microstructures and textures that develop in these thermal stir welds. The observed microstructure was used to reconstruct the high-temperature microstructure and texture present during the welding process and therefore reveal the genesis of the welding structures.

  1. Effect of whitening toothpaste on titanium and titanium alloy surfaces.

    PubMed

    Faria, Adriana Cláudia Lapria; Bordin, Angelo Rafael de Vito; Pedrazzi, Vinícius; Rodrigues, Renata Cristina Silveira; Ribeiro, Ricardo Faria

    2012-01-01

    Dental implants have increased the use of titanium and titanium alloys in prosthetic applications. Whitening toothpastes with peroxides are available for patients with high aesthetic requirements, but the effect of whitening toothpastes on titanium surfaces is not yet known, although titanium is prone to fluoride ion attack. Thus, the aim of the present study was to compare Ti-5Ta alloy to cp Ti after toothbrushing with whitening and conventional toothpastes. Ti-5Ta (%wt) alloy was melted in an arc melting furnace and compared with cp Ti. Disks and toothbrush heads were embedded in PVC rings to be mounted onto a toothbrushing test apparatus. A total of 260,000 cycles were carried out at 250 cycles/minute under a load of 5 N on samples immersed in toothpaste slurries. Surface roughness and Vickers microhardness were evaluated before and after toothbrushing. One sample of each material/toothpaste was analyzed by Scanning Electron Microscopy (SEM) and compared with a sample that had not been submitted to toothbrushing. Surface roughness increased significantly after toothbrushing, but no differences were noted after toothbrushing with different toothpastes. Toothbrushing did not significantly affect sample microhardness. The results suggest that toothpastes that contain and those that do not contain peroxides in their composition have different effects on cp Ti and Ti-5Ta surfaces. Although no significant difference was noted in the microhardness and roughness of the surfaces brushed with different toothpastes, both toothpastes increased roughness after toothbrushing.

  2. Utility of modular implants in primary total hip arthroplasty.

    PubMed

    Berry, Daniel J

    2014-04-01

    Most surgeons believe that some level of modularity has a valuable role to play in primary total hip arthroplasty. However, all modular junctions carry some risk and recent problems with taper tribocorrosion have elevated concerns. These problems suggest that more rigorous preclinical testing should be undertaken before new types of modularity are widely used. Efforts to further optimize these junctions where they are needed, avoidance of gratuitous use of modular junctions where they provide only modest benefits, and a judicious approach to adopting new modularity are reasonable approaches to current concerns. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Method of making multilayered titanium ceramic composites

    SciTech Connect

    Fisher, George T., II; Hansen; Jeffrey S.; Oden; Laurance L.; Turner; Paul C.; Ochs; Thomas L.

    1998-08-25

    A method making a titanium ceramic composite involves forming a hot pressed powder body having a microstructure comprising at least one titanium metal or alloy layer and at least one ceramic particulate reinforced titanium metal or alloy layer and hot forging the hot pressed body follwed by hot rolling to substantially reduce a thickness dimension and substantially increase a lateral dimension thereof to form a composite plate or sheet that retains in the microstructure at least one titanium based layer and at least one ceramic reinforced titanium based layer in the thickness direction of the composite plate or sheet.

  4. Method of making multilayered titanium ceramic composites

    DOEpatents

    Fisher, G.T. II; Hansen, J.S.; Oden, L.L.; Turner, P.C.; Ochs, T.L.

    1998-08-25

    A method making a titanium ceramic composite involves forming a hot pressed powder body having a microstructure comprising at least one titanium metal or alloy layer and at least one ceramic particulate reinforced titanium metal or alloy layer and hot forging the hot pressed body followed by hot rolling to substantially reduce a thickness dimension and substantially increase a lateral dimension thereof to form a composite plate or sheet that retains in the microstructure at least one titanium based layer and at least one ceramic reinforced titanium based layer in the thickness direction of the composite plate or sheet. 3 figs.

  5. Method of making multilayered titanium ceramic composites

    SciTech Connect

    Fisher, II, George T.; Hansen, Jeffrey S.; Oden, Laurance L.; Turner, Paul C.; Ochs, Thomas L.

    1998-01-01

    A method making a titanium ceramic composite involves forming a hot pressed powder body having a microstructure comprising at least one titanium metal or alloy layer and at least one ceramic particulate reinforced titanium metal or alloy layer and hot forging the hot pressed body follwed by hot rolling to substantially reduce a thickness dimension and substantially increase a lateral dimension thereof to form a composite plate or sheet that retains in the microstructure at least one titanium based layer and at least one ceramic reinforced titanium based layer in the thickness direction of the composite plate or sheet.

  6. Method of making multilayered titanium ceramic composites

    SciTech Connect

    Fisher, G.T. II; Hansen, J.S.; Oden, L.L.; Turner, P.C.; Ochs, T.L.

    1998-08-25

    A method making a titanium ceramic composite involves forming a hot pressed powder body having a microstructure comprising at least one titanium metal or alloy layer and at least one ceramic particulate reinforced titanium metal or alloy layer and hot forging the hot pressed body followed by hot rolling to substantially reduce a thickness dimension and substantially increase a lateral dimension thereof to form a composite plate or sheet that retains in the microstructure at least one titanium based layer and at least one ceramic reinforced titanium based layer in the thickness direction of the composite plate or sheet. 3 figs.

  7. Research and Development on Titanium Alloys

    DTIC Science & Technology

    1949-10-31

    svmym lIfe. Th~e rAnge of cOmposila Ivwstpted in the bin"rtniaum-stiver sistems was extended to 5% snw an M~an~Ajmm loy cntprn 0.1 Is beryllium were...extended to 5,0 per cent silverl and titanium- beryllium alloys containing 0.1 to-1.0 per cent berylliuma were inveitiga~ted. None of~ these alloys had...of: 1. Binary titanium-germanium alloys. 2. Binary titanium-nickel alloys. 3, Binary titanium-silver alloys. 4. Binary titanium- beryllium alloys. 5

  8. SMEX-Lite Modular Solar Array Architecture

    NASA Technical Reports Server (NTRS)

    Lyons, John

    2002-01-01

    For the most part, Goddard solar arrays have been custom designs that are unique to each mission. The solar panel design has been frozen prior to issuing an RFP for their procurement. There has typically been 6-9 months between RFP release and contract award, followed by an additional 24 months for performance of the contract. For Small Explorer (SMEX) missions, with three years between mission definition and launch, this has been a significant problem. The SMEX solar panels have been sufficiently small that the contract performance period has been reduced to 12-15 months. The bulk of this time is used up in the final design definition and fabrication of flight solar cell assemblies. Even so, it has been virtually impossible to have the spacecraft design at a level of maturity sufficient to freeze the solar panel geometry and release the RFP in time to avoid schedule problems with integrating the solar panels to the spacecraft. With that in mind, the SMEX-Lite project team developed a modular architecture for the assembly of solar arrays to greatly reduce the cost and schedule associated with the development of a mission- specific solar array. In the modular architecture, solar cells are fabricated onto small substrate panels. This modular panel (approximately 8.5" x 17" in this case) becomes the building block for constructing solar arrays for multiple missions with varying power requirements and geometrical arrangements. The mechanical framework that holds these modules together as a solar array is the only mission-unique design, changing in size and shape as required for each mission. There are several advantages to this approach. First, the typical solar array development cycle requires a mission unique design, procurement, and qualification including a custom qualification panel. With the modular architecture, a single qualification of the SMEX-Lite modules and the associated mechanical framework in a typical configuration provided a qualification by

  9. SMEX-Lite Modular Solar Array Architecture

    NASA Technical Reports Server (NTRS)

    Lyons, John

    2002-01-01

    For the most part, Goddard solar arrays have been custom designs that are unique to each mission. The solar panel design has been frozen prior to issuing an RFP for their procurement. There has typically been 6-9 months between RFP release and contract award, followed by an additional 24 months for performance of the contract. For Small Explorer (SMEX) missions, with three years between mission definition and launch, this has been a significant problem. The SMEX solar panels have been sufficiently small that the contract performance period has been reduced to 12-15 months. The bulk of this time is used up in the final design definition and fabrication of flight solar cell assemblies. Even so, it has been virtually impossible to have the spacecraft design at a level of maturity sufficient to freeze the solar panel geometry and release the RFP in time to avoid schedule problems with integrating the solar panels to the spacecraft. With that in mind, the SMEX-Lite project team developed a modular architecture for the assembly of solar arrays to greatly reduce the cost and schedule associated with the development of a mission- specific solar array. In the modular architecture, solar cells are fabricated onto small substrate panels. This modular panel (approximately 8.5" x 17" in this case) becomes the building block for constructing solar arrays for multiple missions with varying power requirements and geometrical arrangements. The mechanical framework that holds these modules together as a solar array is the only mission-unique design, changing in size and shape as required for each mission. There are several advantages to this approach. First, the typical solar array development cycle requires a mission unique design, procurement, and qualification including a custom qualification panel. With the modular architecture, a single qualification of the SMEX-Lite modules and the associated mechanical framework in a typical configuration provided a qualification by

  10. On the classification of weakly integral modular categories

    SciTech Connect

    Bruillard, Paul; Galindo, César; Ng, Siu-Hung; Plavnik, Julia Y.; Rowell, Eric C.; Wang, Zhenghan

    2016-06-01

    In this paper we classify all modular categories of dimension 4m, where m is an odd square-free integer, and all rank 6 and rank 7 weakly integral modular categories. This completes the classification of weakly integral modular categories through rank 7. In particular, our results imply that all integral modular categories of rank at most 7 are pointed (that is, every simple object has dimension 1). All the non-integral (but weakly integral) modular categories of ranks 6 and 7 have dimension 4m, with m an odd square free integer, so their classification is an application of our main result. The classification of rank 7 integral modular categories is facilitated by an analysis of the two group actions on modular categories: the Galois group of the field generated by the entries of the S-matrix and the group of invertible isomorphism classes of objects. We derive some valuable arithmetic consequences from these actions.

  11. Implicit Contractive Mappings in Modular Metric and Fuzzy Metric Spaces

    PubMed Central

    Hussain, N.; Salimi, P.

    2014-01-01

    The notion of modular metric spaces being a natural generalization of classical modulars over linear spaces like Lebesgue, Orlicz, Musielak-Orlicz, Lorentz, Orlicz-Lorentz, and Calderon-Lozanovskii spaces was recently introduced. In this paper we investigate the existence of fixed points of generalized α-admissible modular contractive mappings in modular metric spaces. As applications, we derive some new fixed point theorems in partially ordered modular metric spaces, Suzuki type fixed point theorems in modular metric spaces and new fixed point theorems for integral contractions. In last section, we develop an important relation between fuzzy metric and modular metric and deduce certain new fixed point results in triangular fuzzy metric spaces. Moreover, some examples are provided here to illustrate the usability of the obtained results. PMID:25003157

  12. Synthesis and properties of nanoscale titanium boride

    NASA Astrophysics Data System (ADS)

    Efimova, K. A.; Galevskiy, G. V.; Rudneva, V. V.

    2015-09-01

    This work reports the scientific and technological grounds for plasma synthesis of titanium diboride, including thermodynamic and kinetic conditions of boride formation when titanium and titanium dioxide are interacting with products resulting from boron gasification in the nitrogen - hydrogen plasma flow, and two variations of its behavior using the powder mixtures: titanium - boron and titanium dioxide - boron. To study these technology variations, the mathematical models were derived, describing the relation between element contents in the synthesized products of titanium and free boron and basic parameters. The probable mechanism proposed for forming titanium diboride according to a "vapour - melt - crystal" pattern was examined, covering condensation of titanium vapour in the form of aerosol, boriding of nanoscale melt droplets by boron hydrides and crystallization of titanium - boron melt. The comprehensive physical - chemical certification of titanium diboride was carried out, including the study of its crystal structure, phase and chemical composition, dispersion, morphology and particle oxidation. Technological application prospects for use of titanium diboride nanoscale powder as constituent element in the wettable coating for carbon cathodes having excellent physical and mechanical performance and protective properties.

  13. Hydrogen content in titanium and a titanium-zirconium alloy after acid etching.

    PubMed

    Frank, Matthias J; Walter, Martin S; Lyngstadaas, S Petter; Wintermantel, Erich; Haugen, Håvard J

    2013-04-01

    Dental implant alloys made from titanium and zirconium are known for their high mechanical strength, fracture toughness and corrosion resistance in comparison with commercially pure titanium. The aim of the study was to investigate possible differences in the surface chemistry and/or surface topography of titanium and titanium-zirconium surfaces after sand blasting and acid etching. The two surfaces were compared by X-ray photoelectron spectroscopy, secondary ion mass spectroscopy, scanning electron microscopy and profilometry. The 1.9 times greater surface hydrogen concentration of titanium zirconium compared to titanium was found to be the major difference between the two materials. Zirconium appeared to enhance hydride formation on titanium alloys when etched in acid. Surface topography revealed significant differences on the micro and nanoscale. Surface roughness was increased significantly (p<0.01) on the titanium-zirconium alloy. High-resolution images showed nanostructures only present on titanium zirconium.

  14. Metal ion levels in ceramic-on-ceramic THR with modular necks: analysis of cobalt and chromium serum levels in 30 healthy hip patients.

    PubMed

    Somers, Jan F A

    2015-01-01

    Modular necks in total hip replacement (THR) can be a source of metal ion release. There are no data to date on the level of cobalt and chromium ions in the serum of patients with a cobalt-chrome stem and a titanium modular neck. Serum ion levels were measured in healthy volunteers with a well-functioning ceramic-on-ceramic THR. Average cobalt in serum was 1.21 µg/l for unilateral THR and 2.2 µg/l for bilateral THR. No patient had cobalt levels higher than 2.4 µg/l. No patient had measurable chromium levels. There were no differences in cobalt levels for hips with short necks versus hips with long necks. The hybrid THR Profemur® Xm - Procotyl® L with a titanium modular neck on a cobalt-chrome stem design shows no signs of abnormal toxic ion levels (cobalt or chromium) in a randomly selected group of well-functioning hip patients.

  15. Robust and fault tolerant control of modular and reconfigurable robots

    NASA Astrophysics Data System (ADS)

    Abdul, Sajan

    Modular and reconfigurable robot has been one of the main areas of robotics research in recent years due to its wide range of applications, especially in aerospace sector. Dynamic control of manipulators can be performed using joint torque sensing with little information of the link dynamics. From the modular robot perspective, this advantage offered by the torque sensor can be taken to enhance the modularity of the control system. Known modular robots though boast novel and diverse mechanical design on joint modules in one way or another, they still require the whole robot dynamic model for motion control, and modularity offered in the mechanical side does not offer any advantage in the control design. In this work, a modular distributed control technique is formulated for modular and reconfigurable robots that can instantly adapt to robot reconfigurations. Under this control methodology, a modular and reconfigurable robot is stabilized joint by joint, and modules can be added or removed without the need of re-tuning the controller. Model uncertainties associated with load and links are compensated by the use of joint torque sensors. Other model uncertainties at each joint module are compensated by a decomposition based robust controller for each module. The proposed distributed control technique offers a 'modular' approach, featuring a unique joint-by-joint control synthesis of the joint modules. Fault tolerance and fault detection are formulated as a decentralized control problem for modular and reconfigurable robots in this thesis work. The modularity of the system is exploited to derive a strategy dependent only on a single joint module, while eliminating the need for the motion states of other joint modules. While the traditional fault tolerant and detection schemes are suitable for robots with the whole dynamic model, this proposed technique is ideal for modular and reconfigurable robots because of its modular nature. The proposed methods have been

  16. PLUTONIUM-URANIUM-TITANIUM ALLOYS

    DOEpatents

    Coffinberry, A.S.

    1959-07-28

    A plutonium-uranium alloy suitable for use as the fuel element in a fast breeder reactor is described. The alloy contains from 15 to 60 at.% titanium with the remainder uranium and plutonium in a specific ratio, thereby limiting the undesirable zeta phase and rendering the alloy relatively resistant to corrosion and giving it the essential characteristic of good mechanical workability.

  17. Lactobacillusassisted synthesis of titanium nanoparticles

    PubMed Central

    2007-01-01

    An eco-friendlylactobacillussp. (microbe) assisted synthesis of titanium nanoparticles is reported. The synthesis is performed at room temperature. X-ray and transmission electron microscopy analyses are performed to ascertain the formation of Ti nanoparticles. Individual nanoparticles as well as a number of aggregates almost spherical in shape having a size of 40–60 nm are found.

  18. Cell Attachment Following Instrumentation with Titanium and Plastic Instruments, Diode Laser, and Titanium Brush on Titanium, Titanium-Zirconium, and Zirconia Surfaces.

    PubMed

    Lang, Melissa S; Cerutis, D Roselyn; Miyamoto, Takanari; Nunn, Martha E

    2016-01-01

    The aim of this study was to evaluate the surface characteristics and gingival fibroblast adhesion of disks composed of implant and abutment materials following brief and repeated instrumentation with instruments commonly used in procedures for implant maintenance, stage-two implant surgery, and periimplantitis treatment. One hundred twenty disks (40 titanium, 40 titaniumzirconium, 40 zirconia) were grouped into treatment categories of instrumentation by plastic curette, titanium curette, diode microlaser, rotary titanium brush, and no treatment. Twenty strokes were applied to half of the disks in the plastic and titanium curette treatment categories, while half of the disks received 100 strokes each to simulate implant maintenance occurring on a repetitive basis. Following analysis of the disks by optical laser profilometry, disks were cultured with human gingival fibroblasts. Cell counts were conducted from scanning electron microscopy (SEM) images. Differences in surface roughness across all instruments tested for zirconia disks were negligible, while both titanium disks and titaniumzirconium disks showed large differences in surface roughness across the spectrum of instruments tested. The rotary titanium brush and the titanium curette yielded the greatest overall mean surface roughness, while the plastic curette yielded the lowest mean surface roughness. The greatest mean cell counts for each disk type were as follows: titanium disks with plastic curettes, titanium-zirconium disks with titanium curettes, and zirconia disks with the diode microlaser. Repeated instrumentation did not result in cumulative changes in surface roughness of implant materials made of titanium, titanium-zirconium, or zirconia. Instrumentation with plastic implant curettes on titanium and zirconia surfaces appeared to be more favorable than titanium implant curettes in terms of gingival fibroblast attachment on these surfaces.

  19. Humeral Tray-Taper Failure in Modular Reverse Total Shoulder Arthroplasty.

    PubMed

    McDonald, Lucas S; Dines, Joshua S; Chin, Christopher; Warren, Russell F; Dines, David M

    2016-02-01

    Reverse total shoulder arthroplasty (RTSA) provides reconstructive options in patients previously not candidates for total shoulder arthroplasty (TSA) or who have failed previous anatomic TSA. Revision from anatomic TSA to RTSA previously required removal of all components, a difficult and extensive procedure. Modular humeral components permit conversion from anatomic TSA to RTSA without removal of well-fixed humeral components. Our purpose is to present a case series of patients treated for the unique and not previously reported complication of humeral tray-taper failure following modular RTSA. Challenges in diagnosis and treatment are described, including the use of dynamic fluoroscopy and manufacturer-specific instruments for component revision. Five patients with a total of six humeral tray-taper failures were identified from 300 patients with first-generation (titanium) humeral trays over a 7-year period. Dynamic fluoroscopic evaluation aided in diagnosis in a majority of the cases. All cases have been revised to second-generation (cobalt chrome) humeral trays. Average follow-up was 22 ± 23 months (range 3-60 months). One individual required a second revision for the same complication, but otherwise, no additional procedures were required. Symptom relief was obtained in all patients. This case series illustrates a previously unpublished complication of humeral tray-taper junction failure following modular RTSA. Clinical and radiographic diagnosis is challenging; however, dynamic fluoroscopic evaluation permits identification of the component failure, and revision surgery results in good outcomes. We must, however, continue to evaluate what activities are recommend for patients following shoulder arthroplasty, specifically reverse total shoulder arthroplasty.

  20. Metal Ion Levels in Young, Active Patients Receiving a Modular, Dual Mobility Total Hip Arthroplasty.

    PubMed

    Nam, Denis; Salih, Rondek; Brown, Katherine M; Nunley, Ryan M; Barrack, Robert L

    2017-05-01

    Dual mobility total hip arthroplasty (THA) components improve stability, yet use of a modular cobalt alloy acetabular liner may be associated with metal ion release. This study's purpose was to measure blood metal ion levels in young, active patients receiving a dual mobility THA prosthesis. This is a prospective study of young, active patients undergoing primary THA. Twenty-six patients received a 22-mm cobalt alloy (n = 10) or a 28-mm ceramic (n = 16) femoral head, a modular cobalt chrome acetabular liner, with a highly cross-linked polyethylene insert (dual mobility). Seventeen control patients received a 32-mm cobalt alloy (n = 6), oxidized zirconium (n = 5), or ceramic (n = 6) femoral head and polyethylene acetabular liner (conventional). All patients received a cementless, titanium femoral stem. Blood metal ion levels (μg/L) were measured preoperatively and at 1 year postoperatively. No difference was present for age or body mass index (P = .5 and .9). At 1 year postoperatively, mean cobalt levels were greater in the dual mobility cohort (0.23 ± 0.39 vs 0.15 ± 0.07, P < .001). Four patients in the dual mobility cohort had a cobalt level outside the reference range (0.03-0.29), with values from 0.34 to 1.81 μg/L. One patient in the conventional cohort had a cobalt level outside the reference range with a value of 0.39 μg/L. The presence and clinical significance of increased cobalt levels in 4 patients with the use of a modular dual mobility prosthesis demonstrates the necessity of continued surveillance. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. High survival of modular tapered stems for proximal femoral bone defects at 5 to 10 years followup.

    PubMed

    Van Houwelingen, Andrew P; Duncan, Clive P; Masri, Bassam A; Greidanus, Nelson V; Garbuz, Donald S

    2013-02-01

    Currently, the two most commonly used options for the revision of femoral components in North America are: cylindrical, nonmodular, cobalt-chromium stems and tapered, fluted, modular, titanium (TFMT) stems. Previous reports have cited high failure rates with cylindrical cobalt chrome stems in large femoral defects but the longer term survival of the fluted stems is unknown. We examined the 5- to 10-year survival of TFMT stems implanted for severe femoral defects. We reviewed all 65 patients with severe proximal bone defects revised with the TMFT stem between January 2000 and 2006. Ten were lost to followup and seven were dead, leaving 48 patients for followup at 5 to 10 years (mean, 84 months; range, 60-120 months). All patients completed five quality-of-life (QOL) questionnaires. Radiographs were evaluated for loosening, subsidence, and preservation of proximal host bone stock. Implant survivorship was 90%. No patient underwent revision for either subsidence or loosening. Subsidence occurred in seven patients (average, 12.3 mm) but all achieved secondary stability. Five patients underwent revision as a result of fracture of the stem and all had the original standard stem design, which has since been modified. All five implant fractures occurred at the modular stem junction. Mean QOL outcomes were: WOMAC = 81 (pain), Oxford = 75, SF-12 = 54 (mental) and 38 (physical), UCLA Activity = 4, and satisfaction overall = 73. Midterm survivorship of modular titanium stems in large femoral defects is high; however, ongoing surveillance of stem junctional fatigue life is required. Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

  2. Effect of trunnion roughness and length on the modular taper junction strength under typical intraoperative assembly forces.

    PubMed

    Jauch-Matt, S Y; Miles, A W; Gill, H S

    2017-01-01

    Modular hip implants are at risk of fretting-induced postoperative complications most likely initiated by micromotion between adjacent implant components. A stable fixation between ball head and stem-neck taper is critical to avoid excessive interface motions. Therefore, the aim of this study was to identify the effect of trunnion roughness and length on the modular taper strength under typical intraoperative assembly forces. Custom-made Titanium trunnions (standard/mini taper, smooth/grooved surface finish) were assembled with modular Cobalt-chromium heads by impaction with peak forces ranging from 2kN to 6kN. After each assembly process these were disassembled with a materials testing machine to detect the pull-off force as a measure for the taper strength. As expected, the pull-off forces increased with rising peak assembly force (p < 0.001). For low and moderate assembly forces, smooth standard tapers offered higher pull-off forces compared to grooved tapers (p < 0.038). In the case of an assembly force of 2kN, mini tapers showed a higher taper strength than standard ones (p=0.037). The results of this study showed that smooth tapers provided a higher strength for taper junctions. This higher taper strength may reduce the risk of fretting-related complications especially in the most common range of intraoperative assembly forces.

  3. Tensile properties of titanium electrolytically charged with hydrogen

    NASA Technical Reports Server (NTRS)

    Smith, R. J.; Otterson, D. A.

    1971-01-01

    Yield strength, ultimate tensile strength, and elongation were studied for annealed titanium electrolytically charged with hydrogen. The hydrogen was present as a surface hydride layer. These tensile properties were generally lower for uncharged titanium than for titanium with a continuous surface hydride; they were greater for uncharged titanium than for titanium with an assumed discontinuous surface hydride. We suggest that the interface between titanium and titanium hydride is weak. And the hydride does not necessarily impair strength and ductility of annealed titanium. The possibility that oxygen and/or nitrogen can embrittle titanium hydride is discussed.

  4. Stress promotes maleness in hermaphroditic modular animals

    PubMed Central

    Hughes, R. N.; Manríquez, P. H.; Bishop, J. D. D.; Burrows, M. T.

    2003-01-01

    Sex-allocation theory developed for hermaphroditic plants predicts that impaired phenotype or reduced parental survivorship caused by environmental stress should induce relatively greater allocation to the male function. We provide experimental evidence of stress-induced maleness, already well documented in flowering plants, in a modular animal. By using cloned copies of replicate genotypes, we show that the marine bryozoan Celleporella hyalina increases the ratio of male to female modules in response to diverse environmental stressors. Mating trials confirmed that paternity is determined by fair-raffle sperm competition, which should obviate local mate competition at characteristic population density and promote the advantage of increased male allocation. The demonstrated similarity to plants transcends specific physiological pathways and suggests that stress-induced bias toward male function is a general response of hermaphroditic modular organisms to impaired prospects for parental productivity or survival. PMID:12930903

  5. Modularity and community structure in networks

    PubMed Central

    Newman, M. E. J.

    2006-01-01

    Many networks of interest in the sciences, including social networks, computer networks, and metabolic and regulatory networks, are found to divide naturally into communities or modules. The problem of detecting and characterizing this community structure is one of the outstanding issues in the study of networked systems. One highly effective approach is the optimization of the quality function known as “modularity” over the possible divisions of a network. Here I show that the modularity can be expressed in terms of the eigenvectors of a characteristic matrix for the network, which I call the modularity matrix, and that this expression leads to a spectral algorithm for community detection that returns results of demonstrably higher quality than competing methods in shorter running times. I illustrate the method with applications to several published network data sets. PMID:16723398

  6. Preliminary design study. Shuttle modular scanning spectroradiometer

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Fundamental concepts on which to base a detailed design for a Shuttle Modular Scanning Spectroradiometer were developed, and a preliminary design is presented. The recommended design features modularity and flexibility. It includes a 75-cm f/1.7-telescope assembly in an all-reflective Schmidt configuration, a solid state scan system (pushbroom) with high resolution over a 15 deg field of view, and ten detector channels covering the spectral range from 0.45 to 12.5 micrometers. It uses charge transfer device techniques to accommodate a large number of detector elements for earth observation measurements. Methods for in-flight radiometric calibration, for image motion compensation, and for data processing are described. Recommendations for ground support equipment are included, and interfaces with the shuttle orbiter vehicle are illustrated.

  7. SMEX-Lite Modular Solar Array Architecture

    NASA Technical Reports Server (NTRS)

    Lyons, John W.; Day, John (Technical Monitor)

    2002-01-01

    The NASA Small Explorer (SMEX) missions have typically had three years between mission definition and launch. This short schedule has posed significant challenges with respect to solar array design and procurement. Typically, the solar panel geometry is frozen prior to going out with a procurement. However, with the SMEX schedule, it has been virtually impossible to freeze the geometry in time to avoid scheduling problems with integrating the solar panels to the spacecraft. A modular solar array architecture was developed to alleviate this problem. This approach involves procuring sufficient modules for multiple missions and assembling the modules onto a solar array framework that is unique to each mission. The modular approach removes the solar array from the critical path of the SMEX integration and testing schedule. It also reduces the cost per unit area of the solar arrays and facilitates the inclusion of experiments involving new solar cell or panel technologies in the SMEX missions.

  8. Modular Chemical Process Intensification: A Review

    SciTech Connect

    Kim, Yong-ha; Park, Lydia K.; Yiacoumi, Sotira; Tsouris, Costas

    2016-06-24

    Modular chemical process intensification can dramatically improve energy and process efficiencies of chemical processes through enhanced mass and heat transfer, application of external force fields, enhanced driving forces, and combinations of different unit operations, such as reaction and separation, in single-process equipment. Dramatic improvements such as these lead to several benefits such as compactness or small footprint, energy and cost savings, enhanced safety, less waste production, and higher product quality. Because of these benefits, process intensification can play a major role in industrial and manufacturing sectors, including chemical, pulp and paper, energy, critical materials, and water treatment, among others. This article provides an overview of process intensification, including definitions, principles, tools, and possible applications, with the objective to contribute to the future development and potential applications of modular chemical process intensification in industrial and manufacturing sectors. Drivers and barriers contributing to the advancement of process intensification technologies are discussed.

  9. On Fusion Algebras and Modular Matrices

    NASA Astrophysics Data System (ADS)

    Gannon, T.; Walton, M. A.

    We consider the fusion algebras arising in e.g. Wess-Zumino-Witten conformal field theories, affine Kac-Moody algebras at positive integer level, and quantum groups at roots of unity. Using properties of the modular matrix S, we find small sets of primary fields (equivalently, sets of highest weights) which can be identified with the variables of a polynomial realization of the Ar fusion algebra at level k. We prove that for many choices of rank r and level k, the number of these variables is the minimum possible, and we conjecture that it is in fact minimal for most r and k. We also find new, systematic sources of zeros in the modular matrix S. In addition, we obtain a formula relating the entries of S at fixed points, to entries of S at smaller ranks and levels. Finally, we identify the number fields generated over the rationals by the entries of S, and by the fusion (Verlinde) eigenvalues.

  10. Siberian company starts up modular refinery

    SciTech Connect

    1996-03-18

    Uraineftegas, a subsidiary of Russian oil giant Lukoil, has started up Siberia`s first modular crude distillation unit. The 2,000 b/d refinery was designed and manufactured by Ventech Engineers Inc., Pasadena, Tex. Uraineftegas is based in Urai, Siberia. Located in the Tyumen region on the Konda river, the remote town is accessible only by air and water. Most of Urai`s crude production--about 50,000 b/d, according to Ventech president Bill Stanley--is shipped by pipeline to the refining centers at Ufa and Omsk. Because there are no products pipelines in which to ship fuels back to Urai, the town needed a small refinery in order to produce its own fuels. This report briefly describes the design ad operation of these modular units. It describes construction techniques and temperature control equipment used to maintain an operational environment under severe winter weather.

  11. CosmoSIS: Modular cosmological parameter estimation

    DOE PAGES

    Zuntz, J.; Paterno, M.; Jennings, E.; ...

    2015-06-09

    Cosmological parameter estimation is entering a new era. Large collaborations need to coordinate high-stakes analyses using multiple methods; furthermore such analyses have grown in complexity due to sophisticated models of cosmology and systematic uncertainties. In this paper we argue that modularity is the key to addressing these challenges: calculations should be broken up into interchangeable modular units with inputs and outputs clearly defined. Here we present a new framework for cosmological parameter estimation, CosmoSIS, designed to connect together, share, and advance development of inference tools across the community. We describe the modules already available in CosmoSIS, including CAMB, Planck, cosmicmore » shear calculations, and a suite of samplers. Lastly, we illustrate it using demonstration code that you can run out-of-the-box with the installer available at http://bitbucket.org/joezuntz/cosmosis« less

  12. CosmoSIS: Modular cosmological parameter estimation

    SciTech Connect

    Zuntz, J.; Paterno, M.; Jennings, E.; Rudd, D.; Manzotti, A.; Dodelson, S.; Bridle, S.; Sehrish, S.; Kowalkowski, J.

    2015-06-09

    Cosmological parameter estimation is entering a new era. Large collaborations need to coordinate high-stakes analyses using multiple methods; furthermore such analyses have grown in complexity due to sophisticated models of cosmology and systematic uncertainties. In this paper we argue that modularity is the key to addressing these challenges: calculations should be broken up into interchangeable modular units with inputs and outputs clearly defined. Here we present a new framework for cosmological parameter estimation, CosmoSIS, designed to connect together, share, and advance development of inference tools across the community. We describe the modules already available in CosmoSIS, including CAMB, Planck, cosmic shear calculations, and a suite of samplers. Lastly, we illustrate it using demonstration code that you can run out-of-the-box with the installer available at http://bitbucket.org/joezuntz/cosmosis

  13. Small satellite modular design and application prospect

    NASA Astrophysics Data System (ADS)

    Yuan, Jie; Chen, Jin-Jun

    1993-01-01

    A small satellite modular architecture is introduced, which is based on systematically analyzing the subsystem functions of small satellites. A whole spacecraft is divided into three modules: the payload module, the attitude control module and the common service module. The payload module offers three versions to select according to payload mass; the attitude control module offers gravity gradient modules, spin stabilized modules and two types of three axis stabilization module; common service module is the small satellite control center including control system, power system and TTC (Telemetry, Tracking and Control) system. Several basic module configurations are possible: gravity gradient model, spin stabilized model, the payload module mass varying between 50 to 150 kg. The use of a Chinese launch vehicle to launch these modular small satellites is possible. Small satellite applications in the military, civil and scientific fields are prospected.

  14. SMARBot: a modular miniature mobile robot platform

    NASA Astrophysics Data System (ADS)

    Meng, Yan; Johnson, Kerry; Simms, Brian; Conforth, Matthew

    2008-04-01

    Miniature robots have many advantages over their larger counterparts, such as low cost, low power, and easy to build a large scale team for complex tasks. Heterogeneous multi miniature robots could provide powerful situation awareness capability due to different locomotion capabilities and sensor information. However, it would be expensive and time consuming to develop specific embedded system for different type of robots. In this paper, we propose a generic modular embedded system architecture called SMARbot (Stevens Modular Autonomous Robot), which consists of a set of hardware and software modules that can be configured to construct various types of robot systems. These modules include a high performance microprocessor, a reconfigurable hardware component, wireless communication, and diverse sensor and actuator interfaces. The design of all the modules in electrical subsystem, the selection criteria for module components, and the real-time operating system are described. Some proofs of concept experimental results are also presented.

  15. Modular Chemical Process Intensification: A Review

    DOE PAGES

    Kim, Yong-ha; Park, Lydia K.; Yiacoumi, Sotira; ...

    2016-06-24

    Modular chemical process intensification can dramatically improve energy and process efficiencies of chemical processes through enhanced mass and heat transfer, application of external force fields, enhanced driving forces, and combinations of different unit operations, such as reaction and separation, in single-process equipment. Dramatic improvements such as these lead to several benefits such as compactness or small footprint, energy and cost savings, enhanced safety, less waste production, and higher product quality. Because of these benefits, process intensification can play a major role in industrial and manufacturing sectors, including chemical, pulp and paper, energy, critical materials, and water treatment, among others. Thismore » article provides an overview of process intensification, including definitions, principles, tools, and possible applications, with the objective to contribute to the future development and potential applications of modular chemical process intensification in industrial and manufacturing sectors. Drivers and barriers contributing to the advancement of process intensification technologies are discussed.« less

  16. Versatile microrobotics using simple modular subunits

    PubMed Central

    Cheang, U Kei; Meshkati, Farshad; Kim, Hoyeon; Lee, Kyoungwoo; Fu, Henry Chien; Kim, Min Jun

    2016-01-01

    The realization of reconfigurable modular microrobots could aid drug delivery and microsurgery by allowing a single system to navigate diverse environments and perform multiple tasks. So far, microrobotic systems are limited by insufficient versatility; for instance, helical shapes commonly used for magnetic swimmers cannot effectively assemble and disassemble into different size and shapes. Here by using microswimmers with simple geometries constructed of spherical particles, we show how magnetohydrodynamics can be used to assemble and disassemble modular microrobots with different physical characteristics. We develop a mechanistic physical model that we use to improve assembly strategies. Furthermore, we experimentally demonstrate the feasibility of dynamically changing the physical properties of microswimmers through assembly and disassembly in a controlled fluidic environment. Finally, we show that different configurations have different swimming properties by examining swimming speed dependence on configuration size. PMID:27464852

  17. Modular organization of axial microcircuits in zebrafish

    PubMed Central

    Bagnall, Martha W.; McLean, David L.

    2014-01-01

    Locomotion requires precise control of spinal networks. In tetrapods and bipeds, dynamic regulation of locomotion is simplified by the modular organization of spinal limb circuits, but it is not known whether their predecessors, fish axial circuits, are similarly organized. Here, we demonstrate that the larval zebrafish spinal cord contains distinct, parallel microcircuits for independent control of dorsal and ventral musculature on each side of the body. During normal swimming, dorsal and ventral microcircuits are equally active; but during postural correction, fish differentially engage these microcircuits to generate torque for self-righting. These findings reveal greater complexity in the axial spinal networks responsible for swimming than previously recognized and suggest an early template of modular organization for more complex locomotor circuits in later vertebrates. PMID:24408436

  18. Siegel modular forms and black hole entropy

    NASA Astrophysics Data System (ADS)

    Belin, Alexandre; Castro, Alejandra; Gomes, João; Keller, Christoph A.

    2017-04-01

    We discuss the application of Siegel Modular Forms to Black Hole entropy counting. The role of the Igusa cusp form χ 10 in the D1D5P system is well-known, and its transformation properties are what allows precision microstate counting in this case. We apply a similar method to extract the Fourier coefficients of other Siegel modular and paramodular forms, and we show that they could serve as candidates for other types of black holes. We investigate the growth of their coefficients, identifying the dominant contributions and the leading logarithmic corrections in various regimes. We also discuss similarities and differences to the behavior of χ 10, and possible physical interpretations of such forms both from a microscopic and gravitational point of view.

  19. A modular approach to adaptive structures.

    PubMed

    Pagitz, Markus; Pagitz, Manuel; Hühne, Christian

    2014-10-07

    A remarkable property of nastic, shape changing plants is their complete fusion between actuators and structure. This is achieved by combining a large number of cells whose geometry, internal pressures and material properties are optimized for a given set of target shapes and stiffness requirements. An advantage of such a fusion is that cell walls are prestressed by cell pressures which increases, decreases the overall structural stiffness, weight. Inspired by the nastic movement of plants, Pagitz et al (2012 Bioinspir. Biomim. 7) published a novel concept for pressure actuated cellular structures. This article extends previous work by introducing a modular approach to adaptive structures. An algorithm that breaks down any continuous target shapes into a small number of standardized modules is presented. Furthermore it is shown how cytoskeletons within each cell enhance the properties of adaptive modules. An adaptive passenger seat and an aircrafts leading, trailing edge is used to demonstrate the potential of a modular approach.

  20. Implementing a modular system of computer codes

    SciTech Connect

    Vondy, D.R.; Fowler, T.B.

    1983-07-01

    A modular computation system has been developed for nuclear reactor core analysis. The codes can be applied repeatedly in blocks without extensive user input data, as needed for reactor history calculations. The primary control options over the calculational paths and task assignments within the codes are blocked separately from other instructions, admitting ready access by user input instruction or directions from automated procedures and promoting flexible and diverse applications at minimum application cost. Data interfacing is done under formal specifications with data files manipulated by an informed manager. This report emphasizes the system aspects and the development of useful capability, hopefully informative and useful to anyone developing a modular code system of much sophistication. Overall, this report in a general way summarizes the many factors and difficulties that are faced in making reactor core calculations, based on the experience of the authors. It provides the background on which work on HTGR reactor physics is being carried out.

  1. Modular stellarator reactor: a fusion power plant

    SciTech Connect

    Miller, R.L.; Bathke, C.G.; Krakowski, R.A.; Heck, F.M.; Green, L.; Karbowski, J.S.; Murphy, J.H.; Tupper, R.B.; DeLuca, R.A.; Moazed, A.

    1983-07-01

    A comparative analysis of the modular stellarator and the torsatron concepts is made based upon a steady-state ignited, DT-fueled, reactor embodiment of each concept for use as a central electric-power station. Parametric tradeoff calculations lead to the selection of four design points for an approx. 4-GWt plant based upon Alcator transport scaling in l = 2 systems of moderate aspect ratio. The four design points represent high-aspect ratio. The four design points represent high-(0.08) and low-(0.04) beta versions of the modular stellarator and torsatron concepts. The physics basis of each design point is described together with supporting engineering and economic analyses. The primary intent of this study is the elucidation of key physics and engineering tradeoffs, constraints, and uncertainties with respect to the ultimate power reactor embodiment.

  2. SMEX-Lite Modular Solar Array Architecture

    NASA Technical Reports Server (NTRS)

    Lyons, John W.; Day, John (Technical Monitor)

    2002-01-01

    The NASA Small Explorer (SMEX) missions have typically had three years between mission definition and launch. This short schedule has posed significant challenges with respect to solar array design and procurement. Typically, the solar panel geometry is frozen prior to going out with a procurement. However, with the SMEX schedule, it has been virtually impossible to freeze the geometry in time to avoid scheduling problems with integrating the solar panels to the spacecraft. A modular solar array architecture was developed to alleviate this problem. This approach involves procuring sufficient modules for multiple missions and assembling the modules onto a solar array framework that is unique to each mission. The modular approach removes the solar array from the critical path of the SMEX integration and testing schedule. It also reduces the cost per unit area of the solar arrays and facilitates the inclusion of experiments involving new solar cell or panel technologies in the SMEX missions.

  3. Modular, bluetooth enabled, wireless electroencephalograph (EEG) platform.

    PubMed

    Lovelace, Joseph A; Witt, Tyler S; Beyette, Fred R

    2013-01-01

    A design for a modular, compact, and accurate wireless electroencephalograph (EEG) system is proposed. EEG is the only non-invasive measure for neuronal function of the brain. Using a number of digital signal processing (DSP) techniques, this neuronal function can be acquired and processed into meaningful representations of brain activity. The system described here utilizes Bluetooth to wirelessly transmit the digitized brain signal for an end application use. In this way, the system is portable, and modular in terms of the device to which it can interface. Brain Computer Interface (BCI) has become a popular extension of EEG systems in modern research. This design serves as a platform for applications using BCI capability.

  4. Modular quantum-information processing by dissipation

    NASA Astrophysics Data System (ADS)

    Marshall, Jeffrey; Campos Venuti, Lorenzo; Zanardi, Paolo

    2016-11-01

    Dissipation can be used as a resource to control and simulate quantum systems. We discuss a modular model based on fast dissipation capable of performing universal quantum computation, and simulating arbitrary Lindbladian dynamics. The model consists of a network of elementary dissipation-generated modules and it is in principle scalable. In particular, we demonstrate the ability to dissipatively prepare all single-qubit gates, and the controlled-not gate; prerequisites for universal quantum computing. We also show a way to implement a type of quantum memory in a dissipative environment, whereby we can arbitrarily control the loss in both coherence, and concurrence, over the evolution. Moreover, our dissipation-assisted modular construction exhibits a degree of inbuilt robustness to Hamiltonian and, indeed, Lindbladian errors, and as such is of potential practical relevance.

  5. Modular Chemical Process Intensification: A Review.

    PubMed

    Kim, Yong-Ha; Park, Lydia K; Yiacoumi, Sotira; Tsouris, Costas

    2017-06-07

    Modular chemical process intensification can dramatically improve energy and process efficiencies of chemical processes through enhanced mass and heat transfer, application of external force fields, enhanced driving forces, and combinations of different unit operations, such as reaction and separation, in single-process equipment. These dramatic improvements lead to several benefits such as compactness or small footprint, energy and cost savings, enhanced safety, less waste production, and higher product quality. Because of these benefits, process intensification can play a major role in industrial and manufacturing sectors, including chemical, pulp and paper, energy, critical materials, and water treatment, among others. This article provides an overview of process intensification, including definitions, principles, tools, and possible applications, with the objective to contribute to the future development and potential applications of modular chemical process intensification in industrial and manufacturing sectors. Drivers and barriers contributing to the advancement of process intensification technologies are discussed.

  6. Modular, Reconfigurable, High-Energy Technology Development

    NASA Technical Reports Server (NTRS)

    Carrington, Connie; Howell, Joe

    2006-01-01

    The Modular, Reconfigurable High-Energy (MRHE) Technology Demonstrator project was to have been a series of ground-based demonstrations to mature critical technologies needed for in-space assembly of a highpower high-voltage modular spacecraft in low Earth orbit, enabling the development of future modular solar-powered exploration cargo-transport vehicles and infrastructure. MRHE was a project in the High Energy Space Systems (HESS) Program, within NASA's Exploration Systems Research and Technology (ESR&T) Program. NASA participants included Marshall Space Flight Center (MSFC), the Jet Propulsion Laboratory (JPL), and Glenn Research Center (GRC). Contractor participants were the Boeing Phantom Works in Huntsville, AL, Lockheed Martin Advanced Technology Center in Palo Alto, CA, ENTECH, Inc. in Keller, TX, and the University of AL Huntsville (UAH). MRHE's technical objectives were to mature: (a) lightweight, efficient, high-voltage, radiation-resistant solar power generation (SPG) technologies; (b) innovative, lightweight, efficient thermal management systems; (c) efficient, 100kW-class, high-voltage power delivery systems from an SPG to an electric thruster system; (d) autonomous rendezvous and docking technology for in-space assembly of modular, reconfigurable spacecraft; (e) robotic assembly of modular space systems; and (f) modular, reconfigurable distributed avionics technologies. Maturation of these technologies was to be implemented through a series of increasingly-inclusive laboratory demonstrations that would have integrated and demonstrated two systems-of-systems: (a) the autonomous rendezvous and docking of modular spacecraft with deployable structures, robotic assembly, reconfiguration both during assembly and (b) the development and integration of an advanced thermal heat pipe and a high-voltage power delivery system with a representative lightweight high-voltage SPG array. In addition, an integrated simulation testbed would have been developed

  7. lazar: a modular predictive toxicology framework

    PubMed Central

    Maunz, Andreas; Gütlein, Martin; Rautenberg, Micha; Vorgrimmler, David; Gebele, Denis; Helma, Christoph

    2013-01-01

    lazar (lazy structure–activity relationships) is a modular framework for predictive toxicology. Similar to the read across procedure in toxicological risk assessment, lazar creates local QSAR (quantitative structure–activity relationship) models for each compound to be predicted. Model developers can choose between a large variety of algorithms for descriptor calculation and selection, chemical similarity indices, and model building. This paper presents a high level description of the lazar framework and discusses the performance of example classification and regression models. PMID:23761761

  8. Copper vapor laser modular packaging assembly

    DOEpatents

    Alger, T.W.; Ault, E.R.; Moses, E.I.

    1992-12-01

    A modularized packaging arrangement for one or more copper vapor lasers and associated equipment is disclosed herein. This arrangement includes a single housing which contains the laser or lasers and all their associated equipment except power, water and neon, and means for bringing power, water, and neon which are necessary to the operation of the lasers into the container for use by the laser or lasers and their associated equipment. 2 figs.

  9. Copper vapor laser modular packaging assembly

    DOEpatents

    Alger, Terry W.; Ault, Earl R.; Moses, Edward I.

    1992-01-01

    A modularized packaging arrangement for one or more copper vapor lasers and associated equipment is disclosed herein. This arrangement includes a single housing which contains the laser or lasers and all their associated equipment except power, water and neon, and means for bringing power, water, and neon which are necessary to the operation of the lasers into the container for use by the laser or lasers and their associated equipment.

  10. Asynchronous networks: modularization of dynamics theorem

    NASA Astrophysics Data System (ADS)

    Bick, Christian; Field, Michael

    2017-02-01

    Building on the first part of this paper, we develop the theory of functional asynchronous networks. We show that a large class of functional asynchronous networks can be (uniquely) represented as feedforward networks connecting events or dynamical modules. For these networks we can give a complete description of the network function in terms of the function of the events comprising the network: the modularization of dynamics theorem. We give examples to illustrate the main results.

  11. Modular control system for optogenetic experiments

    NASA Astrophysics Data System (ADS)

    Sowiński, Mikołaj; Kulik, Paweł; Kasprowicz, Grzegorz; Mankiewicz, Lech; Krawczyk, Rafał D.; Jarosiński, Jakub; Czajkowski, Rafał; Knapska, Ewelina; Puścian, Alicja; Kowalski, Jakub; Rusakov, Konstantin; Przywózki, Tomasz; Rasiński, Paweł; Juszczyk, Bartłomiej

    2016-09-01

    This article presents a modular control system used in Eco-HAB experimentation system. Features specific to the solution are covered. Control system is described in details. The architecture is outlined in the context of requirements to be met. Modes of utilization of implantable device, time synchronization, localization service and antenna driving oscillation fine-tuning as well as preliminary experiments in preparation are described.

  12. Modular Zero Energy. BrightBuilt Home

    SciTech Connect

    Aldrich, Robb; Butterfield, Karla

    2016-03-01

    With funding from the Building America Program, part of the U.S. Department of Energy Building Technologies Office, the Consortium for Advanced Residential Buildings (CARB) worked with BrightBuilt Home (BBH) to evaluate and optimize building systems. CARB’s work focused on a home built by Black Bros. Builders in Lincolnville, Maine (International Energy Conservation Code Climate Zone 6). As with most BBH projects to date, modular boxes were built by Keiser Homes in Oxford, Maine.

  13. Bifurcated, modular syntheses of chiral annulet triazacyclononanes.

    PubMed

    Argouarch, Gilles; Stones, Graham; Gibson, Colin L; Kennedy, Alan R; Sherrington, David C

    2003-12-21

    Three chiral 2,6-disubstituted tri-N-methyl azamacrocycles have been prepared by modular methods. These macrocycles were accessed from three chiral 1,4,7-triazaheptanes intermediates that were prepared by two independent routes. The first of these routes involved the benzylamine opening of chiral tosyl aziridines followed by debenzylation but was problematic on solubility grounds. A second, more effective, route was developed which avoided debenzylation by using ammonia in the nucleophilic opening of chiral tosyl aziridines.

  14. Modular Habitats Comprising Rigid and Inflatable Modules

    NASA Technical Reports Server (NTRS)

    Kennedy, Kriss J.

    2010-01-01

    Modular, lightweight, fully equipped buildings comprising hybrids of rigid and inflatable structures can be assembled on Earth and then transported to and deployed on the Moon for use as habitats. Modified versions of these buildings could also prove useful on Earth as shelters that can be rapidly and easily erected in emergency situations and/or extreme environments: examples include shelters for hurricane relief and for Antarctic exploration.

  15. Workflow and cost analysis on MODULAR ANALYTICS.

    PubMed

    Stolz, Herbert; Dossler, Bettina; Keller, Franz; Steigerwald, Udo

    2003-01-01

    Four stand-alone analyzers in a centralized laboratory were replaced by two modular analytical systems processing 45 methods of the general chemistry and specific protein segment. This consolidation led to a reduction of the daily workflow and operational costs. The cost saving with 1.3 million reported results per year was 53,000 Euro, which can be assessed as an important contribution to cost reduction in the health care system.

  16. Parallel Induction of Modular Classification Rules

    NASA Astrophysics Data System (ADS)

    Stahl, Frederic; Bramer, Max; Adda, Mo

    The Distributed Rule Induction (DRI) project at the University of Portsmouth is concerned with distributed data mining algorithms for automatically generating rules of all kinds. In this paper we present a system architecture and its implementation for inducing modular classification rules in parallel in a local area network using a distributed blackboard system. We present initial results of a prototype implementation based on the Prism algorithm.

  17. Modular vaccine packaging increases packing efficiency.

    PubMed

    Norman, Bryan A; Rajgopal, Jayant; Lim, Jung; Gorham, Katrin; Haidari, Leila; Brown, Shawn T; Lee, Bruce Y

    2015-06-17

    Within a typical vaccine supply chain, vaccines are packaged into individual cylindrical vials (each containing one or more doses) that are bundled together in rectangular "inner packs" for transport via even larger groupings such as cold boxes and vaccine carriers. The variability of vaccine inner pack and vial size may hinder efficient vaccine distribution because it constrains packing of cold boxes and vaccine carriers to quantities that are often inappropriate or suboptimal in the context of country-specific vaccination guidelines. We developed in Microsoft Excel (Microsoft Corp., Redmond, WA) a spreadsheet model that evaluated the impact of different packing schemes for the Benin routine regimen plus the introduction of the Rotarix vaccine. Specifically, we used the model to compare the current packing scheme to that of a proposed modular packing scheme. Conventional packing of a Dometic RCW25 that aims to maximize fully-immunized children (FICs) results in 123 FICs and a packing efficiency of 81.93% compared to a maximum of 155 FICs and 94.1% efficiency for an alternative modular packaging system. Our analysis suggests that modular packaging systems could offer significant advantages over conventional vaccine packaging systems with respect to space efficiency and potential FICs, when they are stored in standard vaccine carrying devices. This allows for more vaccines to be stored within the same volume while also simplifying the procedures used by field workers to pack storage devices. Ultimately, modular packaging systems could be a simple way to help increase vaccine coverage worldwide. Copyright © 2015. Published by Elsevier Ltd.

  18. Integrated modular propulsion for launch vehicles

    NASA Technical Reports Server (NTRS)

    Knuth, William; Crawford, Roger; Litchford, Ron

    1993-01-01

    The paper proposes a modular approach to rocket propulsion which offers a versatile method for realizing the goals of low cost, safety, reliability, and ease of operation. It is shown that, using practical modules made up of only 4-6 individual elements, it is possible to achieve thrust levels of 2-3 mln lbf and more, using turbomachinery, thrust chambers, lines, and valves about the size of SSME hardware. The approach is illustrated by a LOX/LH2 configuration.

  19. Modular vaccine packaging increases packing efficiency

    PubMed Central

    Norman, Bryan A.; Rajgopal, Jayant; Lim, Jung; Gorham, Katrin; Haidari, Leila; Brown, Shawn T.; Lee, Bruce Y.

    2015-01-01

    Background Within a typical vaccine supply chain, vaccines are packaged into individual cylindrical vials (each containing one or more doses) that are bundled together in rectangular “inner packs” for transport via even larger groupings such as cold boxes and vaccine carriers. The variability of vaccine inner pack and vial size may hinder efficient vaccine distribution because it constrains packing of cold boxes and vaccine carriers to quantities that are often inappropriate or suboptimal in the context of country-specific vaccination guidelines. Methods We developed in Microsoft Excel (Microsoft Corp., Redmond, WA) a spreadsheet model that evaluated the impact of different packing schemes for the Benin routine regimen plus the introduction of the Rotarix vaccine. Specifically, we used the model to compare the current packing scheme to that of a proposed modular packing scheme. Results Conventional packing of a Dometic RCW25 that aims to maximize fully-immunized children (FICs) results in 123 FICs and a packing efficiency of 81.93% compared to a maximum of 155 FICs and 94.1% efficiency for an alternative modular packaging system. Conclusions Our analysis suggests that modular packaging systems could offer significant advantages over conventional vaccine packaging systems with respect to space efficiency and potential FICs, when they are stored in standard vaccine carrying devices. This allows for more vaccines to be stored within the same volume while also simplifying the procedures used by field workers to pack storage devices. Ultimately, modular packaging systems could be a simple way to help increase vaccine coverage worldwide. PMID:25957666

  20. Modular architecture for robotics and teleoperation

    DOEpatents

    Anderson, Robert J.

    1996-12-03

    Systems and methods for modularization and discretization of real-time robot, telerobot and teleoperation systems using passive, network based control laws. Modules consist of network one-ports and two-ports. Wave variables and position information are passed between modules. The behavior of each module is decomposed into uncoupled linear-time-invariant, and coupled, nonlinear memoryless elements and then are separately discretized.

  1. Generalized modular-value-based scheme and its generalized modular value

    NASA Astrophysics Data System (ADS)

    Ho, Le Bin; Imoto, Nobuyuki

    2017-03-01

    We consider a generalized modular-value-based scheme based on the standard von Neumann measurement. We model the scheme as an interaction between a quantum system and a discrete quantum pointer where the pointer operator is a projection operator onto one of the states of the basis of the pointer Hilbert space. The interaction strength is made arbitrarily large. After post-selection onto the system, the results of the pointer measurement are the so-called conditional probabilities. We first explicitly derive the analytical expressions of the conditional probabilities, the expectation value, and the average displacement in the measured value of a pointer observable that we name as the pointer quantities. We also provide an expression for a generalized modular value and discuss the relationship between the generalized modular value and generalized weak values. The study then shows that the generalized modular value can characterize these pointer quantities. Then we give applications of our proposal to the cases of a spin-s particle pointer and a semiclassical pointer state. One of the key results is that the amplification effect, similar to the weak-value case, is also observed in the case of the generalized modular value. Our study can also apply to the cases of nonclassical pointer states.

  2. RAMS (Risk Analysis - Modular System) methodology

    SciTech Connect

    Stenner, R.D.; Strenge, D.L.; Buck, J.W.

    1996-10-01

    The Risk Analysis - Modular System (RAMS) was developed to serve as a broad scope risk analysis tool for the Risk Assessment of the Hanford Mission (RAHM) studies. The RAHM element provides risk analysis support for Hanford Strategic Analysis and Mission Planning activities. The RAHM also provides risk analysis support for the Hanford 10-Year Plan development activities. The RAMS tool draws from a collection of specifically designed databases and modular risk analysis methodologies and models. RAMS is a flexible modular system that can be focused on targeted risk analysis needs. It is specifically designed to address risks associated with overall strategy, technical alternative, and `what if` questions regarding the Hanford cleanup mission. RAMS is set up to address both near-term and long-term risk issues. Consistency is very important for any comparative risk analysis, and RAMS is designed to efficiently and consistently compare risks and produce risk reduction estimates. There is a wide range of output information that can be generated by RAMS. These outputs can be detailed by individual contaminants, waste forms, transport pathways, exposure scenarios, individuals, populations, etc. However, they can also be in rolled-up form to support high-level strategy decisions.

  3. Modular Zero Energy. BrightBuilt Home

    SciTech Connect

    Aldrich, Robb; Butterfield, Karla

    2016-03-01

    Kaplan Thompson Architects (KTA) has specialized in sustainable, energy-efficient buildings, and they have designed several custom, zero-energy homes in New England. These zero-energy projects have generally been high-end, custom homes with budgets that could accommodate advanced energy systems. In an attempt to make zero energy homes more affordable and accessible to a larger demographic, KTA explored modular construction as way to provide high-quality homes at lower costs. In the mid-2013, KTA formalized this concept when they launched BrightBuilt Home (BBH). The BBH mission is to offer a line of architect-designed, high-performance homes that are priced to offer substantial savings off the lifetime cost of a typical home and can be delivered in less time. For the past two years, CARB has worked with BBH and Keiser Homes (the primary modular manufacturer for BBH) to discuss challenges related to wall systems, HVAC, and quality control. In Spring of 2014, CARB and BBH began looking in detail on a home to be built in Lincolnville, ME by Black Bros. Builders. This report details the solution package specified for this modular plan and the challenges that arose during the project.

  4. Evolution of a modular software network

    PubMed Central

    Fortuna, Miguel A.; Bonachela, Juan A.; Levin, Simon A.

    2011-01-01

    “Evolution behaves like a tinkerer” (François Jacob, Science, 1977). Software systems provide a singular opportunity to understand biological processes using concepts from network theory. The Debian GNU/Linux operating system allows us to explore the evolution of a complex network in a unique way. The modular design detected during its growth is based on the reuse of existing code in order to minimize costs during programming. The increase of modularity experienced by the system over time has not counterbalanced the increase in incompatibilities between software packages within modules. This negative effect is far from being a failure of design. A random process of package installation shows that the higher the modularity, the larger the fraction of packages working properly in a local computer. The decrease in the relative number of conflicts between packages from different modules avoids a failure in the functionality of one package spreading throughout the entire system. Some potential analogies with the evolutionary and ecological processes determining the structure of ecological networks of interacting species are discussed. PMID:22106260

  5. Modular injection systems for miniature engines

    NASA Astrophysics Data System (ADS)

    Cochran, Mike

    1992-07-01

    Mission requirements for Kinetic Energy Weapons will require miniaturization of current vehicle propulsion systems for future Space Defence Iniative Programs. A modular injection system (MIS) valve is presented which will decrease cost, size and weight of miniaturized storable bipropellant rocket engines and features two poppet-type propellant valve modules pneumatically linked to a pilot solenoid module. A prototype modular injection valve sized for 100lbf thrust was designed and is being tested to show lower costs, fewer moving parts and a reduction in weight and size. Results show that this valve meets objectives of one-half weight, one-half cost and one-fifth the envelopment of current production valves. Studies indicate that a cruciform configuration of four nominal 100lbf thrust engines can be controlled by four modular injection valve systems in a single housing of less than 1.0 m3. Following further development and correlation of results this concept may be scaled to control four higher thrust engines.

  6. Evolution of a modular software network.

    PubMed

    Fortuna, Miguel A; Bonachela, Juan A; Levin, Simon A

    2011-12-13

    "Evolution behaves like a tinkerer" (François Jacob, Science, 1977). Software systems provide a singular opportunity to understand biological processes using concepts from network theory. The Debian GNU/Linux operating system allows us to explore the evolution of a complex network in a unique way. The modular design detected during its growth is based on the reuse of existing code in order to minimize costs during programming. The increase of modularity experienced by the system over time has not counterbalanced the increase in incompatibilities between software packages within modules. This negative effect is far from being a failure of design. A random process of package installation shows that the higher the modularity, the larger the fraction of packages working properly in a local computer. The decrease in the relative number of conflicts between packages from different modules avoids a failure in the functionality of one package spreading throughout the entire system. Some potential analogies with the evolutionary and ecological processes determining the structure of ecological networks of interacting species are discussed.

  7. Modular Closed-Loop Control of Diabetes

    PubMed Central

    Magni, L.; Dassau, E.; Hughes-Karvetski, C.; Toffanin, C.; De Nicolao, G.; Del Favero, S.; Breton, M.; Man, C. Dalla; Renard, E.; Zisser, H.; Doyle, F. J.; Cobelli, C.; Kovatchev, B. P.

    2015-01-01

    Modularity plays a key role in many engineering systems, allowing for plug-and-play integration of components, enhancing flexibility and adaptability, and facilitating standardization. In the control of diabetes, i.e., the so-called “artificial pancreas,” modularity allows for the step-wise introduction of (and regulatory approval for) algorithmic components, starting with subsystems for assured patient safety and followed by higher layer components that serve to modify the patient’s basal rate in real time. In this paper, we introduce a three-layer modular architecture for the control of diabetes, consisting in a sensor/pump interface module (IM), a continuous safety module (CSM), and a real-time control module (RTCM), which separates the functions of insulin recommendation (postmeal insulin for mitigating hyperglycemia) and safety (prevention of hypoglycemia). In addition, we provide details of instances of all three layers of the architecture: the APS© serving as the IM, the safety supervision module (SSM) serving as the CSM, and the range correction module (RCM) serving as the RTCM. We evaluate the performance of the integrated system via in silico preclinical trials, demonstrating 1) the ability of the SSM to reduce the incidence of hypoglycemia under nonideal operating conditions and 2) the ability of the RCM to reduce glycemic variability. PMID:22481809

  8. Understanding Modularity in Molecular Networks Requires Dynamics

    PubMed Central

    Alexander, Roger P.; Kim, Philip M.; Emonet, Thierry; Gerstein, Mark B.

    2014-01-01

    The era of genome sequencing has produced long lists of the molecular parts from which cellular machines are constructed. A fundamental goal in systems biology is to understand how cellular behavior emerges from the interaction in time and space of genetically encoded molecular parts, as well as non-genetically encoded small molecules. Networks provide a natural framework for the organization and quantitative representation of all the available data about molecular interactions. The structural and dynamic properties of molecular networks have been the subject of intense research. Despite major advances, bridging network structure to dynamics – and therefore to behavior – remains challenging. A key concept of modern engineering that recurs in the functional analysis of biological networks is modularity. Most approaches to molecular network analysis rely to some extent on the assumption that molecular networks are modular – that is, they are separable and can be studied to some degree in isolation. We describe recent advances in the analysis of modularity in biological networks, focusing on the increasing realization that a dynamic perspective is essential to grouping molecules into modules and determining their collective function. PMID:19638611

  9. Antimony: a modular model definition language.

    PubMed

    Smith, Lucian P; Bergmann, Frank T; Chandran, Deepak; Sauro, Herbert M

    2009-09-15

    Model exchange in systems and synthetic biology has been standardized for computers with the Systems Biology Markup Language (SBML) and CellML, but specialized software is needed for the generation of models in these formats. Text-based model definition languages allow researchers to create models simply, and then export them to a common exchange format. Modular languages allow researchers to create and combine complex models more easily. We saw a use for a modular text-based language, together with a translation library to allow other programs to read the models as well. The Antimony language provides a way for a researcher to use simple text statements to create, import, and combine biological models, allowing complex models to be built from simpler models, and provides a special syntax for the creation of modular genetic networks. The libAntimony library allows other software packages to import these models and convert them either to SBML or their own internal format. The Antimony language specification and the libAntimony library are available under a BSD license from http://antimony.sourceforge.net/.

  10. Small Modular Reactors (468th Brookhaven Lecture)

    SciTech Connect

    Bari, Robert

    2011-04-20

    With good reason, much more media attention has focused on nuclear power plants than solar farms, wind farms, or hydroelectric plants during the past month and a half. But as nations around the world demand more energy to power everything from cell phone batteries to drinking water pumps to foundries, nuclear plants are the only non-greenhouse-gas producing option that can be built to operate almost anywhere, and can continue to generate power during droughts, after the sun sets, and when winds die down. To supply this demand for power, designers around the world are competing to develop more affordable nuclear reactors of the future: small modular reactors. Brookhaven Lab is working with DOE to ensure that these reactors are designed to be safe for workers, members of surrounding communities, and the environment and to ensure that the radioactive materials and technology will only be used for peaceful purposes, not weapons. In his talk, Bari will discuss the advantages and challenges of small modular reactors and what drives both international and domestic interest in them. He will also explain how Brookhaven Lab and DOE are working to address the challenges and provide a framework for small modular reactors to be commercialized.

  11. MACOP modular architecture with control primitives

    PubMed Central

    Waegeman, Tim; Hermans, Michiel; Schrauwen, Benjamin

    2013-01-01

    Walking, catching a ball and reaching are all tasks in which humans and animals exhibit advanced motor skills. Findings in biological research concerning motor control suggest a modular control hierarchy which combines movement/motor primitives into complex and natural movements. Engineers inspire their research on these findings in the quest for adaptive and skillful control for robots. In this work we propose a modular architecture with control primitives (MACOP) which uses a set of controllers, where each controller becomes specialized in a subregion of its joint and task-space. Instead of having a single controller being used in this subregion [such as MOSAIC (modular selection and identification for control) on which MACOP is inspired], MACOP relates more to the idea of continuously mixing a limited set of primitive controllers. By enforcing a set of desired properties on the mixing mechanism, a mixture of primitives emerges unsupervised which successfully solves the control task. We evaluate MACOP on a numerical model of a robot arm by training it to generate desired trajectories. We investigate how the tracking performance is affected by the number of controllers in MACOP and examine how the individual controllers and their generated control primitives contribute to solving the task. Furthermore, we show how MACOP compensates for the dynamic effects caused by a fixed control rate and the inertia of the robot. PMID:23888140

  12. Effect of plasma nitriding and titanium nitride coating on the corrosion resistance of titanium.

    PubMed

    Wang, Xianli; Bai, Shizhu; Li, Fang; Li, Dongmei; Zhang, Jing; Tian, Min; Zhang, Qian; Tong, Yu; Zhang, Zichuan; Wang, Guowei; Guo, Tianwen; Ma, Chufan

    2016-09-01

    The passive film on the surface of titanium can be destroyed by immersion in a fluoridated acidic medium. Coating with titanium nitride (TiN) may improve the corrosion resistance of titanium. The purpose of this in vitro study was to investigate the effect of duplex treatment with plasma nitriding and TiN coating on the corrosion resistance of cast titanium. Cast titanium was treated with plasma nitriding and TiN coating. The corrosion resistance of the duplex-treated titanium in fluoride-containing artificial saliva was then investigated through electrochemical and immersion tests. The corroded surface was characterized by scanning electron microscopy (SEM) with energy-dispersive spectroscopy surface scan analysis. The data were analyzed using ANOVA (α=.05) RESULTS: Duplex treatment generated a dense and uniform TiN film with a thickness of 4.5 μm. Compared with untreated titanium, the duplex-treated titanium displayed higher corrosion potential (Ecorr) values (P<.001) and lower corrosion current density (Icorr) values (P<.001). SEM results showed that the surface of untreated titanium was more heavily corroded than that of duplex-treated titanium. Surface scan analysis of duplex-treated titanium that had been immersed in artificial saliva containing 2 g/L fluoride revealed fluorine on the titanium surface, whereas fluorine was not observed on the surface of untreated titanium after immersion in fluoride-containing artificial saliva. The concentration of titanium ions released from the treated titanium was less than the amount released from untreated titanium (P<.001). Duplex treatment by plasma nitriding and TiN coating significantly improved the corrosion resistance of cast titanium in a fluoride-containing environment. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  13. Studies of titanium dioxide film growth from titanium tetraisopropoxide

    NASA Astrophysics Data System (ADS)

    Wu, Yuan-Min; Bradley, D. C.; Nix, Roger M.

    1993-01-01

    The surface-mediated decomposition of titanium isopropoxide at low pressures has been followed using temperature-programmed reaction spectroscopy and reactive scattering measurements. Film growth is initiated at ˜ 450 K, with kinetics controlled by the decomposition of adsorbed intermediates, giving a mixture of acetone, isopropanol and propene as gas-phase by-products. At high temperatures (#62;675 K) the principal by-product is propene and adsorption kinetics may become rate-limiting.

  14. Adverse Local Tissue Reaction Arising from Corrosion at the Femoral Neck-Body Junction in a Dual-Taper Stem with a Cobalt-Chromium Modular Neck

    PubMed Central

    Cooper, H. John; Urban, Robert M.; Wixson, Richard L.; Meneghini, R. Michael; Jacobs, Joshua J.

    2013-01-01

    Background: Femoral stems with dual-taper modularity were introduced to allow additional options for hip-center restoration independent of femoral fixation in total hip arthroplasty. Despite the increasing availability and use of these femoral stems, concerns exist about potential complications arising from the modular neck-body junction. Methods: This was a multicenter retrospective case series of twelve hips (eleven patients) with adverse local tissue reactions secondary to corrosion at the modular neck-body junction. The cohort included eight women and three men who together had an average age of 60.1 years (range, forty-three to seventy-seven years); all hips were implanted with a titanium-alloy stem and cobalt-chromium-alloy neck. Patients presented with new-onset and increasing pain at a mean of 7.9 months (range, five to thirteen months) following total hip arthroplasty. After serum metal-ion studies and metal artifact reduction sequence (MARS) magnetic resonance imaging (MRI) revealed abnormal results, the patients underwent hip revision at a mean of 15.2 months (range, ten to twenty-three months). Tissue specimens were examined by a single histopathologist, and the retrieved implants were studied with use of light and scanning electron microscopy. Results: Serum metal levels demonstrated greater elevation of cobalt (mean, 6.0 ng/mL) than chromium (mean, 0.6 ng/mL) or titanium (mean, 3.4 ng/mL). MRI with use of MARS demonstrated adverse tissue reactions in eight of nine patients in which it was performed. All hips showed large soft-tissue masses and surrounding tissue damage with visible corrosion at the modular femoral neck-body junction. Available histology demonstrated large areas of tissue necrosis in seven of ten cases, while remaining viable capsular tissue showed a dense lymphocytic infiltrate. Microscopic analysis was consistent with fretting and crevice corrosion at the modular neck-body interface. Conclusions: Corrosion at the modular neck

  15. Adverse local tissue reaction arising from corrosion at the femoral neck-body junction in a dual-taper stem with a cobalt-chromium modular neck.

    PubMed

    Cooper, H John; Urban, Robert M; Wixson, Richard L; Meneghini, R Michael; Jacobs, Joshua J

    2013-05-15

    Femoral stems with dual-taper modularity were introduced to allow additional options for hip-center restoration independent of femoral fixation in total hip arthroplasty. Despite the increasing availability and use of these femoral stems, concerns exist about potential complications arising from the modular neck-body junction. This was a multicenter retrospective case series of twelve hips (eleven patients) with adverse local tissue reactions secondary to corrosion at the modular neck-body junction. The cohort included eight women and three men who together had an average age of 60.1 years (range, forty-three to seventy-seven years); all hips were implanted with a titanium-alloy stem and cobalt-chromium-alloy neck. Patients presented with new-onset and increasing pain at a mean of 7.9 months (range, five to thirteen months) following total hip arthroplasty. After serum metal-ion studies and metal artifact reduction sequence (MARS) magnetic resonance imaging (MRI) revealed abnormal results, the patients underwent hip revision at a mean of 15.2 months (range, ten to twenty-three months). Tissue specimens were examined by a single histopathologist, and the retrieved implants were studied with use of light and scanning electron microscopy. Serum metal levels demonstrated greater elevation of cobalt (mean, 6.0 ng/mL) than chromium (mean, 0.6 ng/mL) or titanium (mean, 3.4 ng/mL). MRI with use of MARS demonstrated adverse tissue reactions in eight of nine patients in which it was performed. All hips showed large soft-tissue masses and surrounding tissue damage with visible corrosion at the modular femoral neck-body junction. Available histology demonstrated large areas of tissue necrosis in seven of ten cases, while remaining viable capsular tissue showed a dense lymphocytic infiltrate. Microscopic analysis was consistent with fretting and crevice corrosion at the modular neck-body interface. Corrosion at the modular neck-body junction in dual-tapered stems with a modular

  16. Titanium-Oxygen Reactivity Study

    NASA Technical Reports Server (NTRS)

    Chafey, J. E.; Scheck, W. G.; Witzell, W. E.

    1962-01-01

    A program has been conducted at Astronautics to investigate the likelihood of occurrence of the catastrophic oxidation of titanium alloy sheet under conditions which simulate certain cases of accidental failure of the metal while it is in contact with liquid or gaseous oxygen. Three methods of fracturing the metal were used; they consisted of mechanical puncture, tensile fracture of welded joints, and perforation by very high velocity particles. The results of the tests which have been conducted provide further evidence of the reactivity of titanium with liquid and gaseous oxygen. The evidence indicates that the rapid fracturing of titanium sheet while it is in contact with oxygen initiates the catastrophic oxidation reaction. Initiation occurred when the speed of the fracture was some few feet per second, as in both the drop-weight puncture tests and the static tensile fracture tests of welded joints, as well as when the speed was several thousand feet per second, as in the simulated micrometeoroid penetration tests. The slow propagation of a crack, however, did not initiate the reaction. It may logically be concluded that the localized frictional heat of rapid fracture and/or spontaneous oxidation (exothermic) of minute particles emanating from the fracture cause initiation of the reaction. Under conditions of slow fracture, however, the small heat generated may be adequately dissipated and the reaction is not initiated. A portion of the study conducted consisted of investigating various means by which the reaction might be retarded or prevented. Providing a "barrier" at the titanium-oxygen interface consisting of either aluminum metal or a coating of a petroleum base corrosion inhibitor appeared to be only partially effective in retarding the reaction. The accidental puncturing or similar rupturing of thin-walled pressurized oxygen tanks on missiles and space vehicle will usually constitute loss of function, and may sometimes cause their catastrophic destruction

  17. The Emergence of Modularity in Biological Systems

    PubMed Central

    Lorenz, Dirk M.; Jeng, Alice; Deem, Michael W.

    2015-01-01

    In this review, we discuss modularity and hierarchy in biological systems. We review examples from protein structure, genetics, and biological networks of modular partitioning of the geometry of biological space. We review theories to explain modular organization of biology, with a focus on explaining how biology may spontaneously organize to a structured form. That is, we seek to explain how biology nucleated from among the many possibilities in chemistry. The emergence of modular organization of biological structure will be described as a symmetry-breaking phase transition, with modularity as the order parameter. Experimental support for this description will be reviewed. Examples will be presented from pathogen structure, metabolic networks, gene networks, and protein-protein interaction networks. Additional examples will be presented from ecological food networks, developmental pathways, physiology, and social networks. There once were two watchmakers, named Hora and Tempus, who manufactured very fine watches. Both of them were highly regarded, and the phones in their workshops rang frequently — new customers were constantly calling them. However, Hora prospered, while Tempus became poorer and poorer and finally lost his shop. What was the reason? The watches the men made consisted of about 1,000 parts each. Tempus had so constructed his that if he had one partly assembled and had to put it down — to answer the phone say— it immediately fell to pieces and had to be reassembled from the elements. The better the customers liked his watches, the more they phoned him, the more difficult it became for him to find enough uninterrupted time to finish a watch. The watches that Hora made were no less complex than those of Tempus. But he had designed them so that he could put together subassemblies of about ten elements each. Ten of these subassemblies, again, could be put together into a larger subassembly; and a system of ten of the latter sub

  18. Modularization and nuclear power. Report by the Technology Transfer Modularization Task Team

    SciTech Connect

    Not Available

    1985-06-01

    This report describes the results of the work performed by the Technology Transfer Task Team on Modularization. This work was performed as part of the Technology Transfer work being performed under Department of Energy Contract 54-7WM-335406, between December, 1984 and February, 1985. The purpose of this task team effort was to briefly survey the current use of modularization in the nuclear and non-nuclear industries and to assess and evaluate the techniques available for potential application to nuclear power. A key conclusion of the evaluation was that there was a need for a study to establish guidelines for the future development of Light Water Reactor, High Temperature Gas Reactor and Liquid Metal Reactor plants. The guidelines should identify how modularization can improve construction, maintenance, life extension and decommissioning.

  19. Antimicrobial titanium/silver PVD coatings on titanium

    PubMed Central

    Ewald, Andrea; Glückermann, Susanne K; Thull, Roger; Gbureck, Uwe

    2006-01-01

    Background Biofilm formation and deep infection of endoprostheses is a recurrent complication in implant surgery. Post-operative infections may be overcome by adjusting antimicrobial properties of the implant surface prior to implantation. In this work we described the development of an antimicrobial titanium/silver hard coating via the physical vapor deposition (PVD) process. Methods Coatings with a thickness of approximately 2 μm were deposited on titanium surfaces by simultaneous vaporisation of both metals in an inert argon atmosphere with a silver content of approximately 0.7 – 9% as indicated by energy dispersive X-ray analysis. On these surfaces microorganisms and eukaryotic culture cells were grown. Results The coatings released sufficient silver ions (0.5–2.3 ppb) when immersed in PBS and showed significant antimicrobial potency against Staphylococcus epidermis and Klebsiella pneumoniae strains. At the same time, no cytotoxic effects of the coatings on osteoblast and epithelial cells were found. Conclusion Due to similar mechanical performance when compared to pure titanium, the TiAg coatings should be suitable to provide antimicrobial activity on load-bearing implant surfaces. PMID:16556327

  20. Formation of crystalline titanium(IV) phosphates from titanium(III) solutions

    SciTech Connect

    Bortun, A.; Jaimez, E.; Llavona, R.; Garcia, J.R.; Rodriguez, J.

    1995-04-01

    Crystalline phases of titanium (IV) phosphate have been obtained from titanium(III) chloride in phosphoric acid solutions. The {alpha}-titanium phosphate synthesis is possible at low temperature (60--80 C). {gamma}-Titanium phosphate is obtained by reflux with very concentrated phosphoric acid in 3--5 hours by oxidation with O{sub 2}. The influence in these reactions of several factors (concentration of reagents, molar ratio P:Ti in the reaction mixture, temperature and reaction) was studied. The {alpha}-titanium phosphate formation takes place in several steps through the sequential formation of amorphous titanium(IV) phosphate, {gamma}-titanium phosphate and/or a semicrystalline titanium(IV) hydroxophosphate, Ti(OH){sub 2}(HPO{sub 4}){center_dot}H{sub 2}O.

  1. Towards a Formal Basis for Modular Safety Cases

    NASA Technical Reports Server (NTRS)

    Denney, Ewen; Pai, Ganesh

    2015-01-01

    Safety assurance using argument-based safety cases is an accepted best-practice in many safety-critical sectors. Goal Structuring Notation (GSN), which is widely used for presenting safety arguments graphically, provides a notion of modular arguments to support the goal of incremental certification. Despite the efforts at standardization, GSN remains an informal notation whereas the GSN standard contains appreciable ambiguity especially concerning modular extensions. This, in turn, presents challenges when developing tools and methods to intelligently manipulate modular GSN arguments. This paper develops the elements of a theory of modular safety cases, leveraging our previous work on formalizing GSN arguments. Using example argument structures we highlight some ambiguities arising through the existing guidance, present the intuition underlying the theory, clarify syntax, and address modular arguments, contracts, well-formedness and well-scopedness of modules. Based on this theory, we have a preliminary implementation of modular arguments in our toolset, AdvoCATE.

  2. Developments in Titanium Powder Metallurgy

    NASA Astrophysics Data System (ADS)

    Froes, F. H.; Eylon, D.; Eichelman, G. E.; Burte, H. M.

    1980-02-01

    The high buy-to-fly ratio associated with many titanium components, combined with forging and machining difficulties, and recent availability problems, has led to a strong drive for near-net titanium shape fabrication. A very promising method of attaining this goal is powder metallurgy. Two major approaches are considered in this article: the "elemental" and "pre-alloyed" powder methods. Shape-making capability and mechanical properties of both technologies are presented. Consideration is given to the cost-effectiveness of the processes and mechanical performance compared to conventional fabrication methods. Design philosophies, modified to include the presence of foreign particles in the compacted article, are discussed. Emerging advances in the technology are presented and future developments forecast.

  3. Free Form Low Cost Fabrication Using Titanium

    DTIC Science & Technology

    2007-06-29

    nickel-base superalloys . "* The tensile strength as an alloy of titanium can be comparable to that of lower-strength marterisitic stainless and is...better than that of austenitic or ferritic stainless. Alloys can have ultimate strengths comparable to iron base superalloys , such as A286, or cobalt...dependent on composition. Some alloy systems (titanium aluminides ) may have useful strengths above this temperature. "* The cost of titanium, while

  4. Ultrafine-grained titanium for medical implants

    DOEpatents

    Zhu, Yuntian T.; Lowe, Terry C.; Valiev, Ruslan Z.; Stolyarov, Vladimir V.; Latysh, Vladimir V.; Raab, Georgy J.

    2002-01-01

    We disclose ultrafine-grained titanium. A coarse-grained titanium billet is subjected to multiple extrusions through a preheated equal channel angular extrusion (ECAE) die, with billet rotation between subsequent extrusions. The resulting billet is cold processed by cold rolling and/or cold extrusion, with optional annealing. The resulting ultrafine-grained titanium has greatly improved mechanical properties and is used to make medical implants.

  5. Production of titanium from ilmenite: a review

    SciTech Connect

    Kohli, R.

    1981-12-01

    The general principles for beneficiation of titanium ores are reviewed and the specific processes used in individual units in various countries are discussed. This is followed by a critical evaluation of various current and potential reduction methods for the production of titanium metal from the processed concentrates. Finally, the report outlines a research program for the development of a commercially viable alternative method for the production of titanium metal.

  6. Titanium Development Program. Volume 5

    DTIC Science & Technology

    1961-05-01

    Metallurgist Mr. Robert Wichser, Chief Research North American Aviation, Inc. Engineer Columbus, Ohio Republic Aviation Corporation Mr. A.R. Mead... Aviation Corporation Attn: V. N. Ferguson, Mfg. Manager Attn: Adolph Kastelowitz, Chief, P.O. Box 6191 Mfg. Engineering Dallas, Texas r .min coa.e, Ln t...Cru Titanium, Inc. Vice Pres. of Manufacturbng Attn: Dr. W. C. Finaly Great Neck, New York Midland, Pennsylvania Temco Aircraft Corporation Republic

  7. Calculation and modular properties of multiloop superstring amplitudes

    SciTech Connect

    Danilov, G. S.

    2013-06-15

    Multiloop superstring amplitudes are calculated within an extensively used gauge where the two-dimensional gravitino field carries Grassmann moduli. In general, the amplitudes possess, instead of modular symmetry, symmetry with respect to modular transformation supplemented with appropriate transformations of two-dimensional local supersymmetry. If the number of loops is larger than three, the integrationmeasures are notmodular forms, while the expression for the amplitude contains integrals along the boundary of the fundamental region of the modular group.

  8. Young Investigator Program: Modular Paradigm for Scalable Quantum Information

    DTIC Science & Technology

    2016-03-04

    AFRL-AFOSR-VA-TR-2016-0120 Modular Paradigm for Scalable Quantum Information Paola Cappellaro MASSACHUSETTS INSTITUTE OF TECHNOLOGY Final Report 03...AND SUBTITLE Young Investigator Program: Modular Paradigm for Scalable Quantum Information 5a. CONTRACT NUMBER FA9550-12-1-0292 5b. GRANT NUMBER...Modular Paradigm for Scalable Quantum Information” was to address some of the challenges facing the field of quantum information science (QIS). The

  9. Recovery of titanium values from titanium grinding swarf by electric furnace smelting

    DOEpatents

    Gerdemann, Stephen J.; White, Jack C.

    1998-01-01

    A method for the recovery of valuable materials from titanium grinding swarf is provided comprising the steps of sieving the accumulated titanium grinding swarf to remove unwanted coarse trash and grinding wheel fragments, pelletizing, and smelting in an electric arc furnace to produce ferrotitanium and/or high titanium slag.

  10. Recovery of titanium values from titanium grinding swarf by electric furnace smelting

    DOEpatents

    Gerdemann, Stephen J.; White, Jack C.

    1999-01-01

    A method for the recovery of valuable materials from titanium grinding swarf is provided comprising the steps of sieving the accumulated titanium grinding swarf to remove unwanted coarse trash and grinding wheel fragments, pelletizing, and smelting in an electric arc furnace to produce ferrotitanium and/or high titanium slag.

  11. Recovery of titanium values from titanium grinding swarf by electric furnace smelting

    DOEpatents

    Gerdemann, S.J.; White, J.C.

    1998-08-04

    A method for the recovery of valuable materials from titanium grinding swarf is provided comprising the steps of sieving the accumulated titanium grinding swarf to remove unwanted coarse trash and grinding wheel fragments, pelletizing, and smelting in an electric arc furnace to produce ferrotitanium and/or high titanium slag. 1 fig.

  12. Reduction of titanium dioxide to metallic titanium conducted under the autogenic pressure of the reactants.

    PubMed

    Eshed, Michal; Irzh, Alexander; Gedanken, Aharon

    2009-08-03

    We report on a reaction to convert titanium dioxide to titanium. The reduction reaction was done under the autogenic pressure of the reactants at 750 degrees C for 5 h. The MgO, a by-product, was removed by acids to obtain pure metallic titanium.

  13. Recovery of titanium values from titanium grinding swarf by electric furnace smelting

    SciTech Connect

    Gerdemann, S.J.; White, J.C.

    1999-10-19

    A method for the recovery of valuable materials from titanium grinding swarf is provided comprising the steps of sieving the accumulated titanium grinding swarf to remove unwanted coarse trash and grinding wheel fragments, pelletizing, and smelting in an electric arc furnace to produce ferrotitanium and/or high titanium slag.

  14. Fretting behavior of titanium alloys

    SciTech Connect

    Fayeulle, S.; Blanchard, P.; Vincent, L. )

    1993-04-01

    Fretting wear tests were performed on three titanium alloys, alpha + beta-Ti-6Al-4V, alpha-Ti-15V-3Al-3Cr-3Sn, and beta-Ti-15V-3Al-3Cr-3Sn, in air. Friction conditions were chosen in order to get gross slip at the interface. The tangential load was recorded during each cycle of the test. Optical and scanning electron microscopy, grazing incidence X-ray diffraction, energy dispersive X-ray analysis and TEM were used to characterize the superficial surface layers of the specimens after the fretting test. Particle detachment was observed in every case and the friction coefficient was always very high. A hard tribologically transformed structure (TTS) was detected in some areas of the superficial layers. TEM revealed that TTS was formed of ultra fine non-oriented grains of alpha-titanium. No beta phase was detected. The wear debris particles were produced from the transformed areas of the contact zone and were then quickly oxidized in the interface. The formation of the TTS is interpreted in terms of deformation-induced transformation. Role of the TTS on friction and wear behavior of titanium alloys is discussed. 45 refs.

  15. Visible Spectra of Titanium Dioxide

    NASA Astrophysics Data System (ADS)

    Gupta, V.; Nagarajan, R.; Maier, J. P.; Zhuang, X.; Le, A.; Steimle, T. C.

    2011-05-01

    Titanium oxide (TiO) has been extensively studied spectroscopically due to its astrophysical relevance. TiO is the main opacity source in the atmospheres of cool M-type stars in the visible and near infrared. In view of the high cosmic abundance of Ti and O, titanium dioxide (TiO2) is believed to play an important role in dust formation processes from the gas-phase in circumstellar shells of oxygen-rich stars. The electronic spectra of a cold molecular beam of TiO2 have been investigated using mass-resolved resonance enhanced multi-photon ionization and laser induced fluorescence spectroscopy. TiO2 was produced by laser ablation of a pure titanium rod in the presence of a supersonic expanding mixture of approximately 5% O2 in either helium or argon. The spectra were recorded in the region 17500 cm-1 to 22500 cm-1 and the bands assigned to the A1B2 ← X1A1 transition. The origin and harmonic vibrational constants for the A1B2 state were determined to be: T000 = 17593(5) cm-1, ω1 = 876(3) cm-1, ω2 = 184(1) cm-1, and ω3 = 316(2) cm-1. Further, the dispersed fluorescence of a few bands were recorded to obtain vibrational parameters for the X1A1 state.

  16. Method for producing titanium aluminide weld rod

    DOEpatents

    Hansen, Jeffrey S.; Turner, Paul C.; Argetsinger, Edward R.

    1995-01-01

    A process for producing titanium aluminide weld rod comprising: attaching one end of a metal tube to a vacuum line; placing a means between said vacuum line and a junction of the metal tube to prevent powder from entering the vacuum line; inducing a vacuum within the tube; placing a mixture of titanium and aluminum powder in the tube and employing means to impact the powder in the tube to a filled tube; heating the tube in the vacuum at a temperature sufficient to initiate a high-temperature synthesis (SHS) reaction between the titanium and aluminum; and lowering the temperature to ambient temperature to obtain a intermetallic titanium aluminide alloy weld rod.

  17. The effects of hydrogen embrittlement of titanium

    NASA Technical Reports Server (NTRS)

    Taylor, Delbert J.

    1989-01-01

    Titanium alloys, by virtue of their attractive strength to density ratio, fatigue, fracture toughness and corrosion resistance are now commonly used in various aerospace and marine applications. The cost, once very expensive, has been reduced, making titanium even more of a competitive material today. Titanium and titanium alloys have a great affinity to several elements. Hydrogen, even in small amounts, can cause embrittlement, which in turn causes a reduction in strength and ductility. The reduction of strength and ductility is the subject of this investigation.

  18. Haemocompatibility of titanium and its alloys.

    PubMed

    Bakir, Mohammed

    2012-07-01

    This review outlines the current understanding of the interactions of titanium and its alloys with blood components, and the ways in which surface modification techniques can be used to alter the surface physicochemical and topographical features that determine blood-material interactions. Surface modification of the spontaneously formed titanium oxide surface layer is a highly attractive means of improving haemocompatibility without forgoing the advantageous mechanical and physical properties of titanium and its alloys. A number of surface modification techniques and treatment processes are discussed in the context of enhancing the haemocompatibility of titanium and its alloys, with a view to optimising the clinical efficacy of blood-contacting devices and materials.

  19. Welded Permanent Fittings for Titanium Hydraulic Tubing.

    DTIC Science & Technology

    FITTINGS, *HYDRAULIC EQUIPMENT, RIVETED JOINTS, TITANIUM ALLOYS, PIPES , JET TRANSPORT AIRCRAFT, COLD WORKING, PRESSURE, RUPTURE, ARC WELDING , INERT...GAS WELDING , RADIOGRAPHY, STRESS RELIEVING, SUPERSONIC AIRCRAFT, COMMERCIAL AIRCRAFT.

  20. Cascading failures of interdependent modular small-world networks

    NASA Astrophysics Data System (ADS)

    Zhu, Guowei; Wang, Xianpei; Tian, Meng; Dai, Dangdang; Long, Jiachuan; Zhang, Qilin

    2016-07-01

    Much empirical evidence shows that many real-world networks fall into the broad class of small-world networks and have a modular structure. The modularity has been revealed to have an important effect on cascading failure in isolated networks. However, the corresponding results for interdependent modular small-world networks remain missing. In this paper, we investigate the relationship between cascading failures and the intra-modular rewiring probabilities and inter-modular connections under different coupling preferences, i.e. random coupling with modules (RCWM), assortative coupling in modules (ACIM) and assortative coupling with modules (ACWM). The size of the largest connected component is used to evaluate the robustness from global and local perspectives. Numerical results indicate that increasing intra-modular rewiring probabilities and inter-modular connections can improve the robustness of interdependent modular small-world networks under intra-attacks and inter-attacks. Meanwhile, experiments on three coupling strategies demonstrate that ACIM has a better effect on preventing the cascading failures compared with RCWM and ACWM. These results can be helpful to allocate and optimize the topological structure of interdependent modular small-world networks to improve the robustness of such networks.