Sample records for distal interlocking screw

  1. Stress analysis of the distal locking screws for femoral interlocking nailing

    Microsoft Academic Search

    Jinn Lin; Son-Jyh Lin; Po-Quang Chen; Shu-Hua Yang

    2001-01-01

    In femoral locked nailing, the distal locking screws are vulnerable to mechanical failure. Biomechanical studies have shown that the stress on these screws is substantially affected by the fit of the nail in the medullary canal. In this study, a “closed form” mathematical model based on elastic beam-column theory was developed to investigate how the nail–cortical contact, which was simulated

  2. Impact of posterior tibial nail malpositioning on iatrogenic injuries by distal medio-lateral interlocking screws. A cadaveric study on plastinated specimens.

    PubMed

    Wegmann, Kilian; Burkhart, Klaus Josef; Buhl, Jörg; Gausepohl, Thomas; Koebke, Jürgen; Müller, Lars Peter

    2012-12-01

    In intramedullary tibial nailing, multi-planar locking makes stabilization of proximal and distal metaphyseal fractures possible. A known complication in intramedullary nailing of the tibia is iatrogenic injury to neuro-vascular structures caused by the insertion of locking screws. As shown in previous studies, the distal positioning of the nail is important, as it determines the course of the locking bolts. The goal of the present study was to display the consequences of posterior nail malpositioning with respect to the safety of the distal medio-lateral locking screws and the available options. Human cadaveric legs were plastinated according to the sequential plastination technique after intramedullary nailing of the tibia and were then cut transversely. The tibial nails were placed centrally or posteriorly. Macroscopic analysis showed a distinct drawback of posterior nail positioning, with diminished options for the placement of the locking screws and thereby a risk of damaging the anterior and posterior neuro-vascular bundles by distal medio-lateral locking screws. PMID:23409576

  3. Interlocking medullary nails — Radiation doses in distal targeting

    Microsoft Academic Search

    S. Skjeldal; S. Backe

    1987-01-01

    Distal interlocking of intramedullary nails involves the use of a fluoroscope and a targeting device. A specially designed awl makes the interlocking procedure simple and efficient. The 30-cm-long side arm of this awl protects the surgeon's hand from direct radiation, and measurements of X-ray exposure show that the protection against radiation is sufficient.

  4. Reinforcing the role of the conventional C-arm - a novel method for simplified distal interlocking

    PubMed Central

    2012-01-01

    Background The common practice for insertion of distal locking screws of intramedullary nails is a freehand technique under fluoroscopic control. The process is technically demanding, time-consuming and afflicted to considerable radiation exposure of the patient and the surgical personnel. A new concept is introduced utilizing information from within conventional radiographic images to help accurately guide the surgeon to place the interlocking bolt into the interlocking hole. The newly developed technique was compared to conventional freehand in an operating room (OR) like setting on human cadaveric lower legs in terms of operating time and radiation exposure. Methods The proposed concept (guided freehand), generally based on the freehand gold standard, additionally guides the surgeon by means of visible landmarks projected into the C-arm image. A computer program plans the correct drilling trajectory by processing the lens-shaped hole projections of the interlocking holes from a single image. Holes can be drilled by visually aligning the drill to the planned trajectory. Besides a conventional C-arm, no additional tracking or navigation equipment is required. Ten fresh frozen human below-knee specimens were instrumented with an Expert Tibial Nail (Synthes GmbH, Switzerland). The implants were distally locked by performing the newly proposed technique as well as the conventional freehand technique on each specimen. An orthopedic resident surgeon inserted four distal screws per procedure. Operating time, number of images and radiation time were recorded and statistically compared between interlocking techniques using non-parametric tests. Results A 58% reduction in number of taken images per screw was found for the guided freehand technique (7.4 ± 3.4) (mean ± SD) compared to the freehand technique (17.6 ± 10.3) (p < 0.001). Total radiation time (all 4 screws) was 55% lower for the guided freehand technique compared to conventional freehand (p = 0.001). Operating time per screw (from first shot to screw tightened) was on average 22% reduced by guided freehand (p = 0.018). Conclusions In an experimental setting, the newly developed guided freehand technique for distal interlocking has proven to markedly reduce radiation exposure when compared to the conventional freehand technique. The method utilizes established clinical workflows and does not require cost intensive add-on devices or extensive training. The underlying principle carries potential to assist implant positioning in numerous other applications within orthopedics and trauma from screw insertions to placement of plates, nails or prostheses. PMID:22276698

  5. Blocking screws for the treatment of distal femur fractures.

    PubMed

    Seyhan, Mustafa; Cakmak, Selami; Donmez, Ferdi; Gereli, Arel

    2013-07-01

    Intramedullary nailing is one of the most convenient biological options for treating distal femoral fractures. Because the distal medulla of the femur is wider than the middle diaphysis and intramedullary nails cannot completely fill the intramedullary canal, intramedullary nailing of distal femoral fractures can be difficult when trying to obtain adequate reduction. Some different methods exist for achieving reduction. The purpose of this study was determine whether the use of blocking screws resolves varus or valgus and translation and recurvatum deformities, which can be encountered in antegrade and retrograde intramedullary nailing. Thirty-four patients with distal femoral fractures underwent intramedullary nailing between January 2005 and June 2011. Fifteen patients treated by intramedullary nailing and blocking screws were included in the study. Six patients had distal diaphyseal fractures and 9 had distal diaphyseo-metaphyseal fractures. Antegrade nailing was performed in 7 patients and retrograde nailing was performed in 8. Reduction during surgery and union during follow-up were achieved in all patients with no significant complications. Mean follow-up was 26.6 months. Mean time to union was 12.6 weeks. The main purpose of using blocking screws is to achieve reduction, but they are also useful for maintaining permanent reduction. When inserting blocking screws, the screws must be placed 1 to 3 cm away from the fracture line to avoid from propagation of the fracture. When applied properly and in an adequate way, blocking screws provide an efficient solution for deformities encountered during intramedullary nailing of distal femur fractures. PMID:23823053

  6. Far cortical locking screws in distal femur fractures.

    PubMed

    Adams, John D; Tanner, Stephanie L; Jeray, Kyle J

    2015-03-01

    Distal femur fractures routinely heal by secondary bone healing, which relies on interfragmentary motion. Periarticular locking plates are commonly used for fixation in distal femur fractures but are associated with a high nonunion rate, likely due to the stiffness of the constructs. Far cortical locking (FCL) screws are designed to allow micromotion at the near cortex while maintaining purchase in only the far cortex. Although clinical data are limited, these screws have been shown in biomechanical studies to provide excellent interfragmentary motion, and animal models have shown increased callus formation compared with traditional locking screws. The purpose of this study was to examine the clinical effects that FCL screws have on healing in distal femur fractures treated with locked constructs. In this retrospective case series, 15 patients with a distal femur fracture treated with MotionLoc screws (Zimmer, Warsaw, Indiana) were analyzed. Serial radiographs were evaluated for callus presence and time to union. All fractures were either 33-A3 or 33-C2 according to the AO classification system, and 5 (33%) were open. Bone loss was recorded in 2 patients. There were no nonunions, and average time to union was 24 weeks. There were no implant failures, and all 5 open fractures, including the 2 with bone loss, healed without intervention. There was 1 reoperation due to painful hardware. Although this is a small case series, these results are promising. Far cortical locking screws may provide the answer to the high nonunion rate associated with distal femur fractures treated with traditional locked constructs. [Orthopedics. 2015; 38(3):e153-e156.]. PMID:25760500

  7. Biomechanical Comparison of Osteoporotic Distal Radius Fractures Fixed by Distal Locking Screws with Different Length

    PubMed Central

    Liu, Xiong; Wu, Wei-dong; Fang, Ya-feng; Zhang, Mei-chao; Huang, Wen-hua

    2014-01-01

    Objectives To evaluate the postoperative stability of osteoporotic distal radius fractures fixed with distal locking screws with different length. Methods A comminuted extra-articular dorsally unstable distal radius fracture, treated with volar locking plate system, was created. The 18 specimens were randomized into 3 groups based on distal locked screws with different length: Group A had unicortical screws with 50% length to the dorsal cortex. Group B had unicortical screws with 75% length to the dorsal cortex. Group C had bicortical screws. Axial compression and bending loads were imposed on the models before and after cycling testing as well as load to clinical and catastrophic failure. Results Minimum change in stiffness was observed before and after fatigue for all groups. The final stiffness to bending forces was statistically similar in all groups, but stiffness to axial compression was statistically significant different: Group A approached significance with respect to groups B and C (P?=?0.017, 0.009), whereas stiffness in group B and C was statistically similar (P?=?0.93). Load to clinical failure was significantly less for group A (456.54±78.59 N) compared with groups B (580.24±73.85 N) and C (591.07±38.40 N). Load to catastrophic failure was statistically similar between groups, but mean values for Group A were 18% less than means for Group C. Conclusions The volar locking plate system fixed with unicortical locking screws with at least 75% length not only produced early stability for osteoporotic distal radius fractures, but also avoided extensor tendon complications due to dorsal screw protrusion. PMID:25080094

  8. Use of the intraosseous screw for unilateral upper molar distalization and found well balanced occlusion

    Microsoft Academic Search

    Ibrahim Erhan Gelgor; Ali Ihya Karaman; Tamer Buyukyilmaz

    2006-01-01

    BACKGROUND: The aim of this study was to present a temporary anchorage device with intraosseous screw for unilateral molar distalization to make a space for the impacted premolar and to found well balanced occlusion in a case. CASE PRESENTATION: A 13-year-old male who have an impacted premolar is presented with skeletal Class I and dental Class 2 relationship. The screw

  9. Use of the intraosseous screw for unilateral upper molar distalization and found well balanced occlusion

    PubMed Central

    Gelgor, Ibrahim Erhan; Karaman, Ali Ihya; Buyukyilmaz, Tamer

    2006-01-01

    Background The aim of this study was to present a temporary anchorage device with intraosseous screw for unilateral molar distalization to make a space for the impacted premolar and to found well balanced occlusion in a case. Case presentation A 13-year-old male who have an impacted premolar is presented with skeletal Class I and dental Class 2 relationship. The screw was placed and immediately loaded to distalize the left upper first and second molar. The average distalization time to achieve an overcorrected Class I molar relationship was 3.6 months. There was no change in overjet, overbite, or mandibular plane angle measurements. Mild protrusion (0.5 mm) of the upper left central incisor was also recorded. Conclusion Immediately loaded intraosseous screw-supported anchorage unit was successful in achieving sufficient unilateral molar distalization without anchorage loss. This treatment procedure was an alternative treatment to the extraction therapy. PMID:17094798

  10. Distal Tibial Metaphyseal Fractures: Does Blocking Screw Extend the Indication of Intramedullary Nailing?

    PubMed Central

    Moongilpatti Sengodan, Mugundhan; Vaidyanathan, Singaravadivelu; Karunanandaganapathy, Sankaralingam; Subbiah Subramanian, Sukumaran; Rajamani, Samuel Gnanam

    2014-01-01

    Aim. To evaluate the clinical use of blocking screws as a supplement to stability in distal tibial metaphyseal fractures treated with statically locked intramedullary nail. Main Outcome Measurement. Alignment and reduction preoperatively, postoperatively, and at healing were the main outcome measured with an emphasis on maintenance of initial reduction on followup. Patients and Methods. This was a prospective study of 20 consecutive cases of distal tibial metaphyseal fractures treated with statically locked intramedullary nailing with supplementary blocking screw between August 2006 and September 2007 with a maximum followup of 3 years. Medullary canal diameter was measured at the levels of fracture and isthmus. Results. The mean diameter of tibia at the level of isthmus was 11.9?mm and at the fracture site was 22.9?mm. Mean length of distal fracture segment was 4.6?cm. Mean varus/valgus alignment was 10.3?degrees preoperatively and 1.7?degrees immediatly postoperatively and was maintained till union. Using Karlstrom-Olerud score the outcome was excellent to good in 90%. Conclusion. We conclude that the use of blocking screw as a supplement will aid in achieving and maintaining the reduction of distal tibial metaphyseal fractures when treated with intramedullary nailing thereby extending the indication of intramedullary nailing. PMID:24967128

  11. Distal tibial physeal bridge: a complication from a tension band plate and screw construct. Report of a case.

    PubMed

    Oda, Jon E; Thacker, Mihir M

    2013-05-01

    We report on a case of a tension band plate and screw construct (Eight Plate) used over the anterior distal tibia in an 9-year-old girl in an attempt to induce recurvatum of the ankle joint to correct a recalcitrant equinus deformity. With growth of the distal tibial physis, the epiphyseal screw was drawn through the physis into the distal tibial metaphysis, resulting in the creation of a transphyseal bony bar. Caution should be exercised when attempting temporary hemiepiphyseodesis using a plate and screw construct in small epiphyses or in an osteopenic bone. PMID:22158054

  12. The number of locking screws predicts the risk of nonunion and reintervention in periprosthetic total knee arthroplasty fractures treated with a nail.

    PubMed

    Toro-Ibarguen, Ainhoa; Moreno-Beamud, José-Antonio; Porras-Moreno, Miguel-Ángel; Aroca-Peinado, Miguel; León-Baltasar, José-Luis; Jorge-Mora, Alberto-Agustín

    2014-09-24

    Periprosthetic knee fractures following total knee arthroplasty are increasing proportionally to the number of primary procedures done. We performed a retrospective review of Rorabeck type II fractures treated with a retrograde nail, trying to find the relationship between failure and the number of distal locking screws used. Twenty-six patients were included. The number of distal interlocking screws (patients with one or two distal interlocking screws and patients with three screws) correlated with nonunion (p < 0.1), did not correlate with the malunion rate (p > 0.1) and correlated with the reintervention rate (p < 0.1). PMID:25249480

  13. Fracture repair of the distal portion of the radius by use of a condylar screw implant in an adult horse.

    PubMed

    Rodgerson, D H; Wilson, D A; Kramer, J

    2001-06-15

    An 8-year-old American Quarter Horse gelding was evaluated because of an open fracture involving the left radius. The horse had fallen during training and became immediately non-weight-bearing in the left forelimb. On initial evaluation, the horse was unable to bear weight on that limb; radiography revealed a long oblique fracture of the distal metaphysis of the radius with minimal displacement of the fracture fragments. Because of the configuration of the fracture, we recommended surgical intervention with internal fixation. A condylar screw implant and 4.5-mm broad dynamic compression plate were applied to the medial and dorsolateral aspects of the radius, respectively. The horse recovered in a sling and full-limb bandage. Six months after discharge, the horse was reevaluated because of a grade 4/5 lameness in the same limb. Palpation revealed signs of severe pain over the distomedial aspect of the radius. Radiography of the left radius revealed severe osteolysis beneath the distal aspect of the condylar screw implant. Surgical removal of the medial plate was performed. Sixteen months after the initial fracture repair, the horse had returned to light training without signs of lameness. Removal of the dorsal plate may be indicated if this horse is to return to aggressive training or becomes lame in the left forelimb. PMID:11417743

  14. Interlocking inorganic screw helices: synthesis, structure, and magnetism of the novel framework uranium orthothiophoshates A11U7(PS4)13 (A = K, Rb).

    PubMed

    Gieck, Christine; Tremel, Wolfgang

    2002-07-01

    The novel quaternary uranium thiophosphate K11U7(PS4)13 has been synthesized by reacting uranium metal, K2S, S, and P2S5 at 700 degrees C in an evacuated silica tube. The crystal structure was determined by single crystal X-ray diffraction techniques. K11U7(PS4)13 crystallizes in the tetragonal space group I42d (a = 32.048(2) A, c = 17.321(1) A, Z = 8). The structure contains a tunnel framework composed of eight interlocking uranium U7(PS4)13 screw helices, with alkali metal cations residing inside the framework channels. The uranium atoms are coordinated in a bi- or tricapped trigonal prismatic fashion. The screw helices are built up from uranium atoms interconnected by PS4 tetrahedral units. Magnetic susceptibility measurements indicate modified Curie-Weiss-type behavior between 300 and 70 K, with an effective magnetic moment of 2.54 microB per U atom at room temperature and C = 3.78, theta = -14.54, chi 0 = 0.01. The isostructural compound Rb11U7(PS4)13 (a = 32.1641(11) A, c = 17.7244(9) A, Z = 8) was prepared by heating a mixture of the formal composition UPS5 in eutectic LiCl/RbCl melts at 700 degrees C. PMID:12489229

  15. Biomechanical comparison of dynamic condylar screw and locking compression plate fixation in unstable distal femoral fractures: An in vitro study

    PubMed Central

    Singh, Ashutosh Kumar; Rastogi, Amit; Singh, Vakil

    2013-01-01

    Background: Distal femur fractures are difficult to manage and the selection of implant for internal fixation remains controversial. The objective of this study is to establish the relative strength of fixation of a distal femoral locking plate (DFLP) compared with the dynamic condylar screw (DCS) in the distal femur fractures. Materials and Methods: Study was conducted on 16 freshly harvested cadaveric distal femoral specimens, eight implanted with DCS and other eight with DFLP. The construct was made unstable by removing a standard sized medial wedge of 1 cm base (gap-osteotomy) beginning 6 cm proximal to the lateral joint line in distal metaphyseal region with the loss of medial buttress. Fatigue test was conducted under load control mode at the frequency of I Hz. Specimens were subjected to cyclic loading of 2 kN, under observation for 50,000 cycles or until failure/cutout, which ever occurred earlier. Results: In DFLP group, there was no implant failure and the average number of cycles sustained was 50,000. Six out of eight specimens completed 50,000 cycles and two failed in DCS group. The average number of cycles sustained by DCS was 46150. Though the bone quality as assessed by dual energy X-ray absorptiometry DEXA was comparable in both DFLP and DCS group (P = 0.06), none failed in DFLP group and subsidence was 1.02 ± 0.34 mm (range: 0.60-1.32 mm), which was significantly 43% lower (P = 0.006) than subsidence in DCS group (1.82 ± 0.58; range: 1.20-3.08 mm). The average stiffness of DCS group was 52.8 ± 4.2 N/mm, which was significantly lower than average stiffness of locked condylar plate group (71.2 ± 5.1 N/mm) (P = 0.02). Conclusions: DFLP fixation of the distal femur fractures resulted in stronger construct than the DCS fixation in both cyclic loading and ultimate strength in biomechanical testing of a simulated A3 distal femur fracture. PMID:24379469

  16. A locking contoured plate for distal fibular fractures: mechanical evaluation in an osteoporotic bone model using screws of different length.

    PubMed

    Zahn, Robert K; Jakubietz, Michael; Frey, Sönke; Doht, Stefanie; Sauer, Alexander; Meffert, Rainer H

    2014-02-01

    Osteoporotic bone with poor mechanical capacity provides limited stability after fixation of ankle fractures. Stabilization with an implant providing increased fixation strength in osteoporotic bone could reduce failure rates of fixation and allow a more functional treatment. The purpose of this study was to evaluate a locking contoured plate for fixation of distal fibular fractures in comparison with a conventional contoured plate in an osteoporotic bone model. Eighty cylinders of osteoporotic bone surrogates were fixed with the two plates. We performed torque-to-failure and cyclic testing experiments using screws of different length with a Zwick/Roell testing machine. The locking system showed higher torque-to-failure and maximum torque levels as compared with the conventional plate in torque-to-failure experiments and torsional cyclic testing. The locking contoured plate provides improved fixation strength in the osteoporotic bone model. The locking system may be appropriate for fixation of distal fibular fractures, especially in osteoporotic bone with poor mechanical capacity. PMID:23676259

  17. Determination of the Distal Fusion Level in the Management of Thoracolumbar and Lumbar Adolescent Idiopathic Scoliosis Using Pedicle Screw Instrumentation

    PubMed Central

    Kim, Sung-Soo; Kim, Jin-Hyok; Kim, Jong-Woo; Um, Kyu-Sub; Ahn, Soo-Hyung; Suk, Se-Il

    2014-01-01

    Study Design A retrospective study. Purpose To determine the exact distal fusion level in the management of thoracolumbar/lumbar adolescent idiopathic scoliosis (TL/L AIS) using pedicle screw instrumentation (PSI). Overview of Literature The selection of distal fusion level remains controversial in TL/L AIS. Methods Radiographic parameters of 66 TL/L AIS patients were analyzed. The patients were grouped according to the distal fusion level; L3 group (fusion to L3, n=58) and L4 group (fusion to L4, n=8). The L3 group was subdivided into L3A (L3 crosses the mid-sacral line with rotation of less than grade II, n=33) and L3B (L3 does not cross the mid-sacral line or rotation is grade II or more, n=25) based on both bending radiographs. All of the patients in the L4 group had the same location and rotation of L3 in bending films as that of patients in the L3B group. An unsatisfactory result was defined as a lowest instrumented vertebral tilt (LIVT) of more than 10° or coronal balance of more than 15 mm. Results Among the 3 groups, there was a significantly lesser correction in the TL/L curve and LIVT in the L3B group. Unsatisfactory results were obtained in 3 patients (9.1%) of the L3A group, in 15 patients (68.2%) of the L3B group, and in 1 patient (12.5%) of the L4 group with a significant difference. Conclusions In TL/L AIS treatment with PSI, the curve can be fused to L3 with favorable radiographic outcomes when L3 crosses the mid-sacral line with rotation of less than grade II in bending films. Otherwise, fusion has to be extended to L4. PMID:25558324

  18. Radiation exposure to the surgeon during closed interlocking intramedullary nailing

    SciTech Connect

    Levin, P.E.; Schoen, R.W. Jr.; Browner, B.D.

    1987-06-01

    During interlocking intramedullary nailing of twenty-five femoral and five tibial fractures, the primary surgeon wore both a universal film badge on the collar of the lead apron and a thermoluminescent dosimeter ring on the dominant hand to quantify the radiation that he or she received. When distal interlocking was performed, the first ring was removed and a second ring was used so that a separate recording could be made for this portion of the procedure. At the conclusion of the study, all of the recorded doses of radiation were averaged. The average amount of radiation to the head and neck during the entire procedure was 7.0 millirems of deep exposure and 8.0 millirems of shallow exposure. The average dose of radiation to the dominant hand during insertion of the intramedullary nail and the proximal interlocking screw was 13.0 millirems, while the average amount during insertion of the distal interlocking nail was 12.0 millirems. Both of these averages are well within the government guidelines for allowable exposure to radiation during one-quarter (three months) of a year. Precautions that are to be observed during this procedure are recommended.

  19. Distal Femoral Complications Following Antegrade Intramedullary Nail Placement

    PubMed Central

    Fantry, Amanda J.; Elia, Gregory; Vopat, Bryan G.; Daniels, Alan H.

    2015-01-01

    While antegrade nailing for proximal and diaphyseal femur fractures is a commonly utilized fixation method with benefits including early mobilization and high rates of fracture union, both intraoperative and postoperative complications may occur. Intraoperative errors include leg length discrepancy, anterior cortical perforation, malreduction of the fracture, and neurovascular injury, and postoperative complications include nonunion, malunion, infection, and hardware failure. This case series reviews complications affecting the distal femur after intramedullary nailing including fracture surrounding a distal femoral interlocking screw (Case #1), nonunion after dynamization with nail penetration into the knee joint (Case #2), and anterior cortical perforation (Case #3). Prevention of intraoperative and postoperative complications surrounding intramedullary nailing requires careful study of the femoral anatomy and nail design specifications (radius of curvature), consideration of the necessity of distal interlocking screws, the need for close radiographic follow-up after nail placement with X-rays of the entire length of the nail, and awareness of possible nail penetration into the knee joint after dynamization. PMID:25874066

  20. Distal femoral complications following antegrade intramedullary nail placement.

    PubMed

    Fantry, Amanda J; Elia, Gregory; Vopat, Bryan G; Daniels, Alan H

    2015-03-01

    While antegrade nailing for proximal and diaphyseal femur fractures is a commonly utilized fixation method with benefits including early mobilization and high rates of fracture union, both intraoperative and postoperative complications may occur. Intraoperative errors include leg length discrepancy, anterior cortical perforation, malreduction of the fracture, and neurovascular injury, and postoperative complications include nonunion, malunion, infection, and hardware failure. This case series reviews complications affecting the distal femur after intramedullary nailing including fracture surrounding a distal femoral interlocking screw (Case #1), nonunion after dynamization with nail penetration into the knee joint (Case #2), and anterior cortical perforation (Case #3). Prevention of intraoperative and postoperative complications surrounding intramedullary nailing requires careful study of the femoral anatomy and nail design specifications (radius of curvature), consideration of the necessity of distal interlocking screws, the need for close radiographic follow-up after nail placement with X-rays of the entire length of the nail, and awareness of possible nail penetration into the knee joint after dynamization. PMID:25874066

  1. Radiation exposure to the surgeon during closed interlocking intramedullary nailing

    Microsoft Academic Search

    PAUL E. LEVIN; ROBERT W. SCHOEN; BRUCE D. BROWNER

    1987-01-01

    During interlocking intramedullary nailing of twenty-five femoral and five tibial fractures, the primary surgeon wore both a universal film badge on the collar of the lead apron and a thermoluminescent dosimeter ring on the dominant hand to quantify the radiation that he or she received. When distal interlocking was performed, the first ring was removed and a second ring was

  2. Multi-modal intra-operative navigation during distal locking of intramedullary nails.

    PubMed

    Diotte, Benoit; Fallavollita, Pascal; Wang, Lejing; Weidert, Simon; Euler, Ekkehard; Thaller, Peter; Navab, Nassir

    2015-02-01

    The interlocking of intramedullary nails is a technically demanding procedure which involves a considerable amount of X-ray acquisitions; one study lists as many as 48 to successfully complete the procedure and fix screws into 4-6 mm distal holes of the nail. We propose to design an augmented radiolucent drill to assist surgeons in completing the distal locking procedure without any additional X-ray acquisitions. Using an augmented reality fluoroscope that coregisters optical and X-ray images, we exploit solely the optical images to detect the augmented radiolucent drill and estimate its tip position in real-time. Consequently, the surgeons will be able to maintain the down the beam positioning required to drill the screws into the nail holes successfully. To evaluate the accuracy of the proposed augmented drill, we perform a preclinical study involving six surgeons and ask them to perform distal locking on dry bone phantoms. Surgeons completed distal locking 98.3% of the time using only a single X-ray image with an average navigation time of 1.4 ± 0.9 min per hole. PMID:25296403

  3. Lithium Lens Interlocks

    Microsoft Academic Search

    J. Krider

    1985-01-01

    The lithium lens in the antiproton source target vault is protected by an interlock system, which is located in relay racks R5 and R6 near the southwest corner of the Target Hall (building APO). The interlock system consists of crates of commercial signal conditioner and alarm modules built by Acromag, Inc and interlock Master Modules built by Fermilab: Twenty analog

  4. Split spline screw

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (inventor)

    1993-01-01

    A split spline screw type payload fastener assembly, including three identical male and female type split spline sections, is discussed. The male spline sections are formed on the head of a male type spline driver. Each of the split male type spline sections has an outwardly projecting load baring segment including a convex upper surface which is adapted to engage a complementary concave surface of a female spline receptor in the form of a hollow bolt head. Additionally, the male spline section also includes a horizontal spline releasing segment and a spline tightening segment below each load bearing segment. The spline tightening segment consists of a vertical web of constant thickness. The web has at least one flat vertical wall surface which is designed to contact a generally flat vertically extending wall surface tab of the bolt head. Mutual interlocking and unlocking of the male and female splines results upon clockwise and counter clockwise turning of the driver element.

  5. Interlocking wettable ceramic tiles

    DOEpatents

    Tabereaux, Jr., Alton T.; Fredrickson, Guy L.; Groat, Eric; Mroz, Thomas; Ulicny, Alan; Walker, Mark F.

    2005-03-08

    An electrolytic cell for the reduction of aluminum having a layer of interlocking cathode tiles positioned on a cathode block. Each tile includes a main body and a vertical restraining member to prevent movement of the tiles away from the cathode block during operation of the cell. The anode of the electrolytic cell may be positioned about 1 inch from the interlocking cathode tiles.

  6. Interlock Collapsing ALU's

    Microsoft Academic Search

    Stamatis Vassiliadis; James Phillips; Bart Blaner

    1993-01-01

    A device capable of executing interlocked fixed point arithmetic logic unit (ALU) instructions in parallel with other instructions causing the execution interlock is presented. The device incorporates the design of a 3-1 ALU and can execute two's complement, unsigned binary, and binary logical operations. It is shown that status for ALU operations using a 3-1 ALU can be determined in

  7. Specifications SCT Hardwired Interlock Card

    E-print Network

    California at Santa Cruz, University of

    Specifications SCT Hardwired Interlock Card Basic characteristics: Size: 6U by 220 mm, single width Power input: 50~70mA at 5V Signal input: 13 interlock signals (RS422) Signal output: 13 interlock signals (TTL) Function description: Hardwired interlock card provides signal conversion between RS422

  8. Complexity of Interlocking Polyominoes

    E-print Network

    Dhawan, Sidharth

    2011-01-01

    Polyominoes are a subset of polygons which can be constructed from integer-length squares fused at their edges. A system of polygons P is interlocked if no subset of the polygons in P can be removed arbitrarily far away from the rest. It is already known that polyominoes with four or fewer squares cannot interlock. It is also known that determining the interlockedness of polyominoes with an arbitrary number of squares is PSPACE hard. Here, we prove that a system of polyominoes with five or fewer squares cannot interlock, and that determining interlockedness of a system of polyominoes including hexominoes (polyominoes with six squares) or larger polyominoes is PSPACE hard.

  9. Intrapelvic Migration of the Lag Screw in Intramedullary Nailing

    PubMed Central

    Toki, Shunichi; Hamada, Daisuke; Yoshioka, Shinji; Tsutsui, Takahiko; Tamaki, Yasuaki; Sairyo, Koichi

    2014-01-01

    Internal fixation with intramedullary devices has gained popularity for the treatment of intertrochanteric femoral fractures, which are common injuries in the elderly. The most common complications are lag screw cut out from the femoral head and femoral fracture at the distal tip of the nail. We report here a rare complication of postoperative lag screw migration into the pelvis with no trauma. The patient was subsequently treated with lag screw removal and revision surgery with total hip arthroplasty. This case demonstrated that optimal fracture reduction and positioning of the lag screw are the most important surgical steps for decreasing the risk of medial migration of the lag screw. Furthermore, to prevent complications, careful attention should be paid to subsequent steps such as precise insertion of the set screw. PMID:25610680

  10. Ball screw inspection setup

    NASA Astrophysics Data System (ADS)

    Janusz, Rzepka; Sambor, Slawomir; Pienkowski, Janusz; Bielenin, Marcin

    2003-05-01

    In the following paper we describe arrangements of laser interferometer for investigation of screws and for inspection of ball screws. We have constructed two of them, namely: the technological setup for investigations of screw in process of production and the ball screw inspection setup. The former one is used to measure the pitch of screws. The data gathered during measurement is used to calculate the parameters for grinding machine. The later setup is used for testing parameters of complete ball screws. The software supporting this setup makes calculation of parameters of tested ball screw and creation of reports possible. Additionally, the inspection setup is the one that the torque measuring arrangements have been integrated on. Both the arrangements and the software allow for measurements of all parameters during movement of nut in full travel length of the ball screw and make charts and reports.

  11. Prevention of excessive medialisation of trochanteric fracture by a buttress screw: a novel method and finite element analysis.

    PubMed

    Mahaisavariya, Banchong; Chantarapanich, Nattapon; Riansuwan, Kongkhet; Sitthiseripratip, Kriskrai

    2014-09-01

    This paper proposes a novel method of using an antero-posterior buttress screw at the distal fragment just below the fracture site in conjunction with the sliding hip screw (SHS) to resist excessive femoral medialisation. A virtual assessment of the effectiveness of this new method was performed using the finite element analysis. The results indicate that the use ofa sliding hip screw (SHS) combined with a buttress screw can help resistfemoral medialisation better than using an SHS with no buttress screw. The von Mises equivalent stress (EQ ) was found to be in a safe range, which indicates increased integrity of the lateral wall with the addition of the buttress screw. PMID:25365905

  12. Quantitative Shape Measurements of Distal Volcanic Ash Colleen M. Riley, William I. Rose, and Gregg J.S. Bluth

    E-print Network

    Rose, William I.

    Quantitative Shape Measurements of Distal Volcanic Ash Colleen M. Riley, William I. Rose, and Gregg interlocking are related to shape (Gilbert and Lane, 1994). The ability of satellite sensors to accurately

  13. Screw Dislocations in Graphite.

    PubMed

    Hennig, G R

    1965-02-12

    Graphite contains varying concentrations of screw dislocations whose Burgers vector parallels the c axis. Single crystals of natural graphite contain very few such dislocations; furthermore, their Burgers vector always exceeds 450 angstroms. Pyrolytic graphites annealed above 3000 degrees C contain abundant screw dislocations, ranging from 10(6) to 5 x 10(8) per square centimeter in two different samples prepared by somewhat different methods. The Burgers vectors of these screws are predominantly 3.35 angstroms. PMID:17758193

  14. 49 CFR 236.772 - Machine, interlocking.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 4 2014-10-01 2014-10-01 false Machine, interlocking. 236.772 Section 236.772 Transportation Other...AND APPLIANCES Definitions § 236.772 Machine, interlocking. An assemblage of manually operated levers or other...

  15. 49 CFR 236.750 - Interlocking, automatic.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...Transportation 4 2014-10-01 2014-10-01 false Interlocking, automatic. 236.750 Section 236.750 Transportation...DEVICES, AND APPLIANCES Definitions § 236.750 Interlocking, automatic. An arrangement of signals, with or...

  16. 49 CFR 236.750 - Interlocking, automatic.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...Transportation 4 2011-10-01 2011-10-01 false Interlocking, automatic. 236.750 Section 236.750 Transportation...DEVICES, AND APPLIANCES Definitions § 236.750 Interlocking, automatic. An arrangement of signals, with or...

  17. 49 CFR 236.772 - Machine, interlocking.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 4 2011-10-01 2011-10-01 false Machine, interlocking. 236.772 Section 236.772 Transportation Other...AND APPLIANCES Definitions § 236.772 Machine, interlocking. An assemblage of manually operated levers or other...

  18. 49 CFR 236.750 - Interlocking, automatic.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...Transportation 4 2012-10-01 2012-10-01 false Interlocking, automatic. 236.750 Section 236.750 Transportation...DEVICES, AND APPLIANCES Definitions § 236.750 Interlocking, automatic. An arrangement of signals, with or...

  19. 49 CFR 236.750 - Interlocking, automatic.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...Transportation 4 2010-10-01 2010-10-01 false Interlocking, automatic. 236.750 Section 236.750 Transportation...DEVICES, AND APPLIANCES Definitions § 236.750 Interlocking, automatic. An arrangement of signals, with or...

  20. 49 CFR 236.772 - Machine, interlocking.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 4 2013-10-01 2013-10-01 false Machine, interlocking. 236.772 Section 236.772 Transportation Other...AND APPLIANCES Definitions § 236.772 Machine, interlocking. An assemblage of manually operated levers or other...

  1. 49 CFR 236.750 - Interlocking, automatic.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...Transportation 4 2013-10-01 2013-10-01 false Interlocking, automatic. 236.750 Section 236.750 Transportation...DEVICES, AND APPLIANCES Definitions § 236.750 Interlocking, automatic. An arrangement of signals, with or...

  2. 49 CFR 236.772 - Machine, interlocking.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 4 2012-10-01 2012-10-01 false Machine, interlocking. 236.772 Section 236.772 Transportation Other...AND APPLIANCES Definitions § 236.772 Machine, interlocking. An assemblage of manually operated levers or other...

  3. Volatile and Interlocked ClassVolatile and Interlocked Class Sandino Vargas

    E-print Network

    Yang, Zijiang "James"

    Volatile and Interlocked ClassVolatile and Interlocked Class Sandino Vargas CS 6030: Introduction to Multicore Programming Spring 2011 #12;General Idea You can use Volatile or Interlocked Class operations. for (;;) { if (finished) { Console.WriteLine("result = {0}", result); return; } } } } #12;Interlocked Class Provides

  4. Modelling and Verification of Relay Interlocking Systems

    E-print Network

    Modelling and Verification of Relay Interlocking Systems Morten Aanæs Hoang Phuong Thai Kongens.imm.dtu.dk #12;Summary Electrical relay based interlocking systems are widely used by Banedanmark to ensure safe and safety property generation of the external part of a particular type of relay interlocking system

  5. Simulation of Relay Interlocking Louise Elmose Eriksen

    E-print Network

    Simulation of Relay Interlocking Systems Louise Elmose Eriksen Boe Pedersen Kongens Lyngby 2007 IMM. These systems are called interlocking systems and prevent trains from collid- ing and derailing. Different interlocking systems are currently implemented in the Danish railway networks. This project is concerned

  6. HAPPY COUPLINGS: EMERGENCE AND. EXPLANATORY INTERLOCK

    E-print Network

    Clark, Andy

    9 HAPPY COUPLINGS: EMERGENCE AND. EXPLANATORY INTERLOCK ANDY CLARK INTRODUCTION: EMERGENCE by Artificwl Life. #12;EMERGENCE AND EXPLANATORY INTERLOCK 263 I shall argue that emergent phenomena do require, is to develop and carefully interlock both types of explanation. 1. THREE EXPLANATORY STYLES In this section I

  7. Modelling Interlocking Systems for Railway Stations

    E-print Network

    Modelling Interlocking Systems for Railway Stations Marie Le Bliguet Andreas Andersen Kjær Kongens reception@imm.dtu.dk www.imm.dtu.dk #12;Summary Interlocking systems are used for ensuring the safety-based interlocking systems for railway stations. The goal of this project is to develop a formal method for verifying

  8. Interlocking of learning and orthonormalization in RRLSA

    E-print Network

    Moeller, Ralf

    Interlocking of learning and orthonormalization in RRLSA Ralf M¨oller 1 Cognitive Robotics, Max show how the effort may be reduced by a factor of up to two by interlocking learning and the Gram by interlocking the learning method -- specifically RRLSA [3] -- with the Gram-Schmidt method, exploiting the fact

  9. Comparison of Maxillary Molar Distalization with an Implant-Supported Distal Jet and a Traditional Tooth-Supported Distal Jet Appliance

    PubMed Central

    Cozzani, Mauro; Pasini, Marco; Zallio, Francesco; Ritucci, Robert; Mutinelli, Sabrina; Mazzotta, Laura; Giuca, Maria Rita; Piras, Vincenzo

    2014-01-01

    Aim. To investigate and compare the efficiency of two appliances for molar distalization: the bone-anchored distal screw (DS) and the traditional tooth-supported distal jet (DJ) for molar distalization and anchorage loss. Methods. Tests (18 subjects) were treated with a DS and controls (18 subjects) were treated with a DJ. Lateral cephalograms were obtained before and at the end of molar distalization and were analysed. Shapiro Wilk test, unpaired t-test, and Wilcoxon rank-sum test were applied according to values distribution. The ? level was fixed at 0.05. Results. Maxillary first molars were successfully distalized into a Class I relationship in all patients. The mean molar distalization and treatment time were similar in both groups. The DS group exhibited a spontaneous distalization (2.1 ± 0.9?mm) of the first premolar with control of anchorage loss, distal tipping, extrusion, and skeletal changes. Conclusions. The DS is an adequate compliance-free distalizing appliance that can be used safely for the correction of Class II malocclusions. In comparison to the traditional DJ, the DS enables not only a good rate of molar distalization, but also a spontaneous distalization of the first premolars. PMID:25018770

  10. Reducing radiation exposure in intra-medullary nailing procedures: Intra-medullary endo-transilluminating (iMET)

    E-print Network

    the distal interlocking screw holes.19,25,8,1,37 This is because the nail is embedded in the medullary cavity the subsequent placing of the interlocking screw. Applicability of TADs is further impaired by the fact that nail the positioning of intra-medullary interlocking screws. Biological tissues are translucent to light over

  11. Solar heat collector with interlocking expandable construction

    SciTech Connect

    Hoffman, L.E.; Warne, D.M.

    1980-08-19

    A solar heat collector comprised of modular elements which may be easily assembled and disassembled without any special tools is described. The system is comprised of a plurality of conduits arranged in a planar fashion for collecting solar heat and joined at their ends by interlocking connectors. The interlocking connectors are elbows and tees which have interlocking male and female flanges which may be easily connected and disconnected. Additional conduits may be added as needed and the length of the conduits may be increased by use of an interlocking coupler. The interlocking nature of the conduits, connectors and couplers allows the entire system to be constructed and disassembled. The interlocking connectors form input and output manifolds through which a heat-collecting fluid may be circulated. An adapter is provided for connecting a pipe for delivering the circulating fluid. The adapter has a neck having a predetermined inner and outer diameter for use with two standard pipe sizes.

  12. 2. ENVIRONMENT, FROM SOUTHEAST, SHOWING B&P INTERLOCKING TOWER, AUXILIARY INTERLOCKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. ENVIRONMENT, FROM SOUTHEAST, SHOWING B&P INTERLOCKING TOWER, AUXILIARY INTERLOCKING BUILDING, AND POWER SUBSTATION - Baltimore & Potomac Interlocking Tower, Adjacent to AMTRAK railroad tracks in block bounded by Howard Street, Jones Falls Expressway, Maryland Avenue & Falls Road, Baltimore, Independent City, MD

  13. 12 CFR 26.4 - Interlocking relationships permitted by statute.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...and Banking 1 2010-01-01 2010-01-01 false Interlocking relationships permitted by statute. 26.4 Section 26...THE TREASURY MANAGEMENT OFFICIAL INTERLOCKS § 26.4 Interlocking relationships permitted by statute. The...

  14. Requirements on the interlock system for Super Structure Tests

    E-print Network

    Requirements on the interlock system for Super Structure Tests · Instantaneous temperature rise based interlock (BLM) · To guarantee the functionality of the Beam Loss Monitor System (BLM) based.Pugachov 10photomultipliersarerequired cablesexistaswellasrequiredPMtypes PhotomultiplierInterlock

  15. 12 CFR 212.4 - Interlocking relationships permitted by statute.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...and Banking 2 2013-01-01 2013-01-01 false Interlocking relationships permitted by statute. 212.4 Section...RESERVE SYSTEM MANAGEMENT OFFICIAL INTERLOCKS § 212.4 Interlocking relationships permitted by statute. The...

  16. 12 CFR 26.4 - Interlocking relationships permitted by statute.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...and Banking 1 2014-01-01 2014-01-01 false Interlocking relationships permitted by statute. 26.4 Section 26...THE TREASURY MANAGEMENT OFFICIAL INTERLOCKS § 26.4 Interlocking relationships permitted by statute. The...

  17. 12 CFR 348.4 - Interlocking relationships permitted by statute.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...and Banking 4 2011-01-01 2011-01-01 false Interlocking relationships permitted by statute. 348.4 Section...GENERAL POLICY MANAGEMENT OFFICIAL INTERLOCKS § 348.4 Interlocking relationships permitted by statute. The...

  18. 12 CFR 348.4 - Interlocking relationships permitted by statute.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...and Banking 5 2012-01-01 2012-01-01 false Interlocking relationships permitted by statute. 348.4 Section...GENERAL POLICY MANAGEMENT OFFICIAL INTERLOCKS § 348.4 Interlocking relationships permitted by statute. The...

  19. 12 CFR 212.4 - Interlocking relationships permitted by statute.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...and Banking 2 2012-01-01 2012-01-01 false Interlocking relationships permitted by statute. 212.4 Section...RESERVE SYSTEM MANAGEMENT OFFICIAL INTERLOCKS § 212.4 Interlocking relationships permitted by statute. The...

  20. 12 CFR 26.4 - Interlocking relationships permitted by statute.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...and Banking 1 2011-01-01 2011-01-01 false Interlocking relationships permitted by statute. 26.4 Section 26...THE TREASURY MANAGEMENT OFFICIAL INTERLOCKS § 26.4 Interlocking relationships permitted by statute. The...

  1. 12 CFR 711.4 - Interlocking relationships permitted by statute.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...and Banking 6 2010-01-01 2010-01-01 false Interlocking relationships permitted by statute. 711.4 Section...CREDIT UNIONS MANAGEMENT OFFICIAL INTERLOCKS § 711.4 Interlocking relationships permitted by statute. The...

  2. 12 CFR 711.4 - Interlocking relationships permitted by statute.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...and Banking 7 2012-01-01 2012-01-01 false Interlocking relationships permitted by statute. 711.4 Section...CREDIT UNIONS MANAGEMENT OFFICIAL INTERLOCKS § 711.4 Interlocking relationships permitted by statute. The...

  3. 12 CFR 26.4 - Interlocking relationships permitted by statute.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...and Banking 1 2012-01-01 2012-01-01 false Interlocking relationships permitted by statute. 26.4 Section 26...THE TREASURY MANAGEMENT OFFICIAL INTERLOCKS § 26.4 Interlocking relationships permitted by statute. The...

  4. Edinburgh Research Explorer The contributions of interlocking loops and extensive

    E-print Network

    Millar, Andrew J.

    Edinburgh Research Explorer The contributions of interlocking loops and extensive nonlinearity 2010, 'The contributions of interlocking loops and extensive nonlinearity to the properties and investigate your claim. Download date: 16. Jun. 2014 #12;The Contributions of Interlocking Loops and Extensive

  5. 12 CFR 711.4 - Interlocking relationships permitted by statute.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...and Banking 7 2013-01-01 2013-01-01 false Interlocking relationships permitted by statute. 711.4 Section...CREDIT UNIONS MANAGEMENT OFFICIAL INTERLOCKS § 711.4 Interlocking relationships permitted by statute. The...

  6. 12 CFR 711.4 - Interlocking relationships permitted by statute.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...and Banking 6 2011-01-01 2011-01-01 false Interlocking relationships permitted by statute. 711.4 Section...CREDIT UNIONS MANAGEMENT OFFICIAL INTERLOCKS § 711.4 Interlocking relationships permitted by statute. The...

  7. 12 CFR 212.4 - Interlocking relationships permitted by statute.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...and Banking 2 2011-01-01 2011-01-01 false Interlocking relationships permitted by statute. 212.4 Section...RESERVE SYSTEM MANAGEMENT OFFICIAL INTERLOCKS § 212.4 Interlocking relationships permitted by statute. The...

  8. 12 CFR 26.4 - Interlocking relationships permitted by statute.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...and Banking 1 2013-01-01 2013-01-01 false Interlocking relationships permitted by statute. 26.4 Section 26...THE TREASURY MANAGEMENT OFFICIAL INTERLOCKS § 26.4 Interlocking relationships permitted by statute. The...

  9. 12 CFR 348.4 - Interlocking relationships permitted by statute.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...and Banking 4 2010-01-01 2010-01-01 false Interlocking relationships permitted by statute. 348.4 Section...GENERAL POLICY MANAGEMENT OFFICIAL INTERLOCKS § 348.4 Interlocking relationships permitted by statute. The...

  10. 12 CFR 348.4 - Interlocking relationships permitted by statute.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...and Banking 5 2013-01-01 2013-01-01 false Interlocking relationships permitted by statute. 348.4 Section...GENERAL POLICY MANAGEMENT OFFICIAL INTERLOCKS § 348.4 Interlocking relationships permitted by statute. The...

  11. 12 CFR 212.4 - Interlocking relationships permitted by statute.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...and Banking 2 2014-01-01 2014-01-01 false Interlocking relationships permitted by statute. 212.4 Section...RESERVE SYSTEM MANAGEMENT OFFICIAL INTERLOCKS § 212.4 Interlocking relationships permitted by statute. The...

  12. 12 CFR 348.4 - Interlocking relationships permitted by statute.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...and Banking 5 2014-01-01 2014-01-01 false Interlocking relationships permitted by statute. 348.4 Section...GENERAL POLICY MANAGEMENT OFFICIAL INTERLOCKS § 348.4 Interlocking relationships permitted by statute. The...

  13. 12 CFR 212.4 - Interlocking relationships permitted by statute.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...and Banking 2 2010-01-01 2010-01-01 false Interlocking relationships permitted by statute. 212.4 Section...RESERVE SYSTEM MANAGEMENT OFFICIAL INTERLOCKS § 212.4 Interlocking relationships permitted by statute. The...

  14. 12 CFR 711.4 - Interlocking relationships permitted by statute.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...and Banking 7 2014-01-01 2014-01-01 false Interlocking relationships permitted by statute. 711.4 Section...CREDIT UNIONS MANAGEMENT OFFICIAL INTERLOCKS § 711.4 Interlocking relationships permitted by statute. The...

  15. Rotordynamics of Twin-Screw Pumps

    E-print Network

    Aboel Hassan Muhammed, Ameen

    2013-02-26

    Twin-screw pumps are positive displacement machines. Two meshing screws connected by timing gears convey the fluid trapped in the screw chambers axially from suction to discharge and force it out against the back pressure. Because of the screw...

  16. Bending strength and holding power of tibial locking screws.

    PubMed

    Lin, J; Lin, S J; Chiang, H; Hou, S M

    2001-04-01

    The bending strength and holding power of two types of specially designed tibial locking devices, a both-ends-threaded screw and an unthreaded bolt, were studied and compared with four types of commercially available tibial interlocking screws: Synthes, Howmedica, Richards, and Osteo AG. To test bending strength, the devices were inserted into a high molecular weight polyethylene tube and loaded at their midpoint by a materials testing machine to simulate a three point bending test. Single loading yielding strength and cyclic loading fatigue life were measured. To test holding power, the devices were inserted into tubes made of polyurethane foam, and their tips were loaded axially to measure pushout strength. The devices were tested with two different densities of foam materials and two different sizes of pilot holes. Insertion torque and stripping torque of the screws were measured first. Pushout tests were performed with each screw inserted with a tightness equal to 60% of its stripping torque. Test results showed that the yielding strength and the fatigue life were related closely to the inner diameter of the screws. The stripping torque predicted the pushout strength more reliably than did the insertion torque. All tested devices showed greater holding power in the foam with the higher density and with the smaller pilot holes. The both-ends-threaded screw had the highest pushout strength and a satisfactory fatigue strength. The unthreaded bolt had the highest fatigue strength but only fair holding power. Clinical studies of the use of these two types of locking devices are worthwhile. PMID:11302315

  17. Electrochemical cell with interlocking anode

    SciTech Connect

    Haskins, T.B.; Goebel, F.; Batson, D.C.; Zuffante, C.R.

    1987-08-04

    A reserve cell is described comprised of: a cylindrical housing having an interior wall; a cylindrical cathode current collector member abutting the interior wall; a cylindrical anode member with a spiral gap; a cylindrical porous separator interposed between the cathode current collector member and the anode member; a liquid cell component container centrally located within the housing; and a continuous anode support cylinder located between the anode member and the container. The anode cylinder has perforations into which the anode member is pressed, interlocking the anode member and the anode support cylinder.

  18. Helical screw viscometer

    DOEpatents

    Aubert, J.H.; Chapman, R.N.; Kraynik, A.M.

    1983-06-30

    A helical screw viscometer for the measurement of the viscosity of Newtonian and non-Newtonian fluids comprising an elongated cylindrical container closed by end caps defining a circular cylindrical cavity within the container, a cylindrical rotor member having a helical screw or ribbon flight carried by the outer periphery thereof rotatably carried within the cavity whereby the fluid to be measured is confined in the cavity filling the space between the rotor and the container wall. The rotor member is supported by axle members journaled in the end caps, one axle extending through one end cap and connectable to a drive source. A pair of longitudinally spaced ports are provided through the wall of the container in communication with the cavity and a differential pressure meter is connected between the ports for measuring the pressure drop caused by the rotation of the helical screw rotor acting on the confined fluid for computing viscosity.

  19. 1. VIEW, LOOKING EAST, FROM UNION STATION, INTERLOCKING TOWER AT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. VIEW, LOOKING EAST, FROM UNION STATION, INTERLOCKING TOWER AT RIGHT - Promenade Street Interlocking Tower, Promenade Street between Union Station & East Side Tunnel Viaduct, Providence, Providence County, RI

  20. Minimizing the complications of intramedullary nailing for distal third tibial shaft and metaphyseal fractures

    PubMed Central

    Yaligod, Vishwanath; Rudrappa, Girish H.; Nagendra, Srinivas; Shivanna, Umesh M.

    2013-01-01

    Background The complications of intramedullary nailing of distal third tibial shaft and metaphyseal fractures have a direct impact on ankle and hind foot function. Methods We retrospectively evaluated 28 patients. Unreamed nail was negotiated across the well reduced fracture till subchondral bone and fixed with 2 to 3 distal locking screws in different planes. Results Fracture union rate was 85%. Three out of 28 patients had malalignment. Mean ankle, hindfoot functional score was 85. Conclusion Complications can be minimized by impacting the unreamed nail till the subchondral bone while maintaining the fracture well reduced and by using multiple distal locking screws in different planes. PMID:24719527

  1. Active interlock for storage ring insertion devices

    Microsoft Academic Search

    J. L. Rothman; R. J. Nawrocky

    1989-01-01

    The insertion devices in the NSLS (National Synchrotron Light Source) X-ray ring produce such intense photon beams that passive measures alone are not adequate to protect the vacuum chamber. An active interlock is used to prevent thermal damage from improperly steered electron beams. The interlock system measures the position of the electron beam on both sides of the insertion devices

  2. The Screw-worm.

    E-print Network

    Francis, M. (Mark)

    1890-01-01

    , it is thought advisable to give a more exhaustive report of the life history of the insect, together with illustrations (see note 1) and description (see note 2) for identification. The screw-worm is the larva or maggot of a dipterous insect (Lacilia macel...

  3. NUT SCREW MECHANISMS

    Microsoft Academic Search

    1958-01-01

    A reactor control mechanism is described wherein the control is achieved ; by the partial or total withdrawal of the fissile material which is in the form ; of a fuel rod. The fuel rod is designed to be raised and lowered from the ; reactor core area by means of two concentric ball nut and screw assemblies that ;

  4. Orthodontic Treatment of Skeletal Class II Adolescent with Anterior Open Bite using Mini-Screws and Modified Palatal Anchorage Plate.

    PubMed

    Kook, Y A; Park, J H; Kim, Y; Ahn, C S; Bayome, M

    2015-01-01

    This article presents a non-extraction orthodontic treatment case using mini-screws and a modified palatal anchorage plate (MPAP) to intrude the maxillary posterior teeth, and distalize the whole arch dentition and control the extrusion of the maxillary posterior dentition during distalization. PMID:25823491

  5. Interlocked Open and Closed Linkages with Few Joints

    E-print Network

    O'Rourke, Joseph

    Interlocked Open and Closed Linkages with Few Joints Erik D. Demaine #3; Stefan Langerman y Joseph that are interlocked in the sense that the linkages cannot be separated without one bar crossing through another. We, and determine which can be interlocked. In particular, we show that a triangle and an open 4-chain can interlock

  6. Verification of solid state interlocking programs Phillip James1

    E-print Network

    Moller, Faron G.

    Verification of solid state interlocking programs Phillip James1 , Andy Lawrence1 , Faron Moller1 in railway interlocking design between programming the interlock- ing and testing this program. Safety still in the case of ladder logic programs and give re- sults for real world railway interlockings

  7. Interlocked Surfaces: A Dynamic Multi-device Collaboration System

    E-print Network

    Tanaka, Jiro

    Interlocked Surfaces: A Dynamic Multi-device Collaboration System Hiroyuki Kamo and Jiro Tanaka. In this research, we propose "Interlocked Surfaces", which supports cooperation work between different devices comfortably using the proposed system. 1 Interlocked Surfaces We propose "Interlocked Surfaces" in this paper

  8. Biomechanical effects of plate area and locking screw on medial open tibial osteotomy.

    PubMed

    Luo, Chu-An; Lin, Shang-Chih; Hwa, Su-Yang; Chen, Chun-Ming; Tseng, Ching-Shiow

    2015-01-01

    Medial open high tibial osteotomy (HTO) has been used to treat osteoarthritis of the medial compartment of the knee. However, weaker plate strength, unstable plate/screw junction and improper surgery technique are highly related to the HTO outcomes. Two ?-shape plates were designed and eight variations (two supporting area × four locking stiffness) were compared by finite-element method. The computed tomography-based tibia was reconstructed and both wedge micromotion and implant stresses were chosen as the comparison indices. The construct was subjected to surgical and physiological loads. The medial-posterior region is the most loaded region and the load through the posterior leg is about four times that through the anterior leg. This indicates that the two-leg design can form a force-couple mechanism to effectively reduce the implant stresses. The use of locking screws significantly decrease the screw and hole stresses. However, the extending plate reduces the stresses of screws and holes above the wedge but makes the distal screws and holes much stressed. Wedge micromotion is affected by extending plate rather than locking screw. Three factors contribute to effective stabilisation of unstable HTO wedge: (1) intimate tibia-plate contact at medial-posterior regions, (2) sufficient rigidity at plate-screw junctions and (3) effective moment-balancing design at distal tibia-plate interfaces. PMID:24617553

  9. Distal Convoluted Tubule

    PubMed Central

    Ellison, David H.

    2014-01-01

    The distal convoluted tubule is the nephron segment that lies immediately downstream of the macula densa. Although short in length, the distal convoluted tubule plays a critical role in sodium, potassium, and divalent cation homeostasis. Recent genetic and physiologic studies have greatly expanded our understanding of how the distal convoluted tubule regulates these processes at the molecular level. This article provides an update on the distal convoluted tubule, highlighting concepts and pathophysiology relevant to clinical practice. PMID:24855283

  10. 49 CFR 236.772 - Machine, interlocking.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 false Machine, interlocking. 236... RULES, STANDARDS, AND INSTRUCTIONS GOVERNING THE INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN...Definitions § 236.772 Machine,...

  11. 49 CFR 236.751 - Interlocking, manual.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...TRANSPORTATION RULES, STANDARDS, AND INSTRUCTIONS GOVERNING THE INSTALLATION, INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES...appliances operated from an interlocking machine and so interconnected by means...

  12. Synthesis of mechanically interlocked oligomacrocyclic systems 

    E-print Network

    Kroll, Marius Matthias

    2011-01-01

    This thesis presents a modular palladium(II) template-directed synthetic strategy towards mechanically interlocked polymacrocyclic architectures, such as a Borromean link and linear [n]-catenanes. Central to the synthetic ...

  13. A target vacuum interlock system for Gammasphere.

    SciTech Connect

    Lister, C. J.; McCutchan, E. A.; Greene, J. P.; Physics

    2009-08-21

    An interlock system is described that allows volatile targets to be prepared in an evaporator, sealed under vacuum, transported to the {gamma}-array Gammasphere, and inserted into the reaction chamber for experiments, while maintaining a vacuum better than 10{sup -5} torr. The performance of the system is demonstrated for lithium metal targets. A comparison is made between lithium targets covered by a gold evaporation to reduce oxidation and open metal targets transferred in the interlock.

  14. Interlocking egg-crate type grid assembly

    DOEpatents

    Kast, S.J.

    1985-03-15

    Disclosed is an interlocking egg-crate hexagonal grid for supporting a nuclear fuel pin in a hexagonal array. The grid is formed from strips bent at an angle of about 120/sup 0/ at each vertex. Over some faces of each hexagonal cell the strips are coplanar but are arranged, by stacking interlocking, to avoid any double thickness of metal in that plane. Springs and dimples are formed in the faces of each cell to hold the fuel pin substantially centered.

  15. Interlocking egg-crate type grid assembly

    DOEpatents

    Kast, Steven J. (Niskayuna, NY)

    1987-01-01

    Disclosed is an interlocking egg-crate hexagonal grid for supporting a nuclear fuel pin in a hexagonal array. The grid is formed from strips bent at an angle of about 120.degree. at each vertex. Over some faces of each hexagonal cell the strips are coplanar but are arranged, by stacking and interlocking, to avoid any double thickness of metal in that plane. Springs and dimples are formed in the faces of each cell to hold the fuel pin substantially centered.

  16. 49 CFR 236.340 - Electromechanical interlocking machine; locking between electrical and mechanical levers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 false Electromechanical interlocking machine; locking between electrical...SYSTEMS, DEVICES, AND APPLIANCES Interlocking Rules and Instructions § 236.340 Electromechanical interlocking machine; locking between...

  17. 49 CFR 236.340 - Electromechanical interlocking machine; locking between electrical and mechanical levers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 false Electromechanical interlocking machine; locking between electrical...SYSTEMS, DEVICES, AND APPLIANCES Interlocking Rules and Instructions § 236.340 Electromechanical interlocking machine; locking between...

  18. 49 CFR 236.340 - Electromechanical interlocking machine; locking between electrical and mechanical levers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 false Electromechanical interlocking machine; locking between electrical...SYSTEMS, DEVICES, AND APPLIANCES Interlocking Rules and Instructions § 236.340 Electromechanical interlocking machine; locking between...

  19. Standardized palmar plating of dorsally displaced distal radius fractures.

    PubMed

    Löw, Steffen; Herold, Dirk; Eingartner, Christoph

    2013-06-01

    With the inauguration of fixed-angle plates, palmar plating has become a widely accepted way to treat dorsally displaced distal radius fractures. The technique by which the plate is applied to the radius varies. Such plates are primarily fixed either distally or at the proximal limbs. In this article, the standardized technique by which osteosynthesis is conducted in our institution is described step by step. The plate is first fixed to the shaft. Reduction is temporarily maintained by K-wires that run through the plate's distal margin. These K-wires are usually reliable in maintaining adequate reduction and are gradually replaced by locking screws in the distal row. Of 96 consecutive procedures, the duration of operation, the amount of fluoroscopy needed, and the intraoperative radiographic results are reported. Using this method, constantly good results can be achieved, even if the operation is done by less experienced surgeons. PMID:23689859

  20. 12 CFR 563f.9 - Interlocking relationships permitted pursuant to Federal Deposit Insurance Act.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 2012-01-01 true Interlocking relationships permitted pursuant to...OFFICIAL INTERLOCKS § 563f.9 Interlocking relationships permitted pursuant to...may enter into an otherwise prohibited interlocking relationship with another...

  1. 12 CFR 563f.9 - Interlocking relationships permitted pursuant to Federal Deposit Insurance Act.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 2011-01-01 false Interlocking relationships permitted pursuant to...OFFICIAL INTERLOCKS § 563f.9 Interlocking relationships permitted pursuant to...may enter into an otherwise prohibited interlocking relationship with another...

  2. 12 CFR 196.9 - Interlocking relationships permitted pursuant to Federal Deposit Insurance Act.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 2013-01-01 false Interlocking relationships permitted pursuant to...MANAGEMENT OFFICIAL INTERLOCKS § 196.9 Interlocking relationships permitted pursuant to...may enter into an otherwise prohibited interlocking relationship with another...

  3. 12 CFR 563f.9 - Interlocking relationships permitted pursuant to Federal Deposit Insurance Act.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 2012-01-01 true Interlocking relationships permitted pursuant to...OFFICIAL INTERLOCKS § 563f.9 Interlocking relationships permitted pursuant to...may enter into an otherwise prohibited interlocking relationship with another...

  4. 12 CFR 390.408 - Interlocking relationships permitted pursuant to Federal Deposit Insurance Act.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 2014-01-01 false Interlocking relationships permitted pursuant to...Official Interlocks § 390.408 Interlocking relationships permitted pursuant to...enter into an otherwise prohibited interlocking relationship with another...

  5. 12 CFR 563f.9 - Interlocking relationships permitted pursuant to Federal Deposit Insurance Act.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 2010-01-01 false Interlocking relationships permitted pursuant to...OFFICIAL INTERLOCKS § 563f.9 Interlocking relationships permitted pursuant to...may enter into an otherwise prohibited interlocking relationship with another...

  6. 12 CFR 390.408 - Interlocking relationships permitted pursuant to Federal Deposit Insurance Act.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 2012-01-01 false Interlocking relationships permitted pursuant to...Official Interlocks § 390.408 Interlocking relationships permitted pursuant to...enter into an otherwise prohibited interlocking relationship with another...

  7. 12 CFR 238.99 - Interlocking relationships permitted pursuant to Federal Deposit Insurance Act.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 2013-01-01 false Interlocking relationships permitted pursuant to...Official Interlocks § 238.99 Interlocking relationships permitted pursuant to...enter into an otherwise prohibited interlocking relationship with another...

  8. 12 CFR 563f.9 - Interlocking relationships permitted pursuant to Federal Deposit Insurance Act.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 2012-01-01 false Interlocking relationships permitted pursuant to...OFFICIAL INTERLOCKS § 563f.9 Interlocking relationships permitted pursuant to...may enter into an otherwise prohibited interlocking relationship with another...

  9. 12 CFR 196.9 - Interlocking relationships permitted pursuant to Federal Deposit Insurance Act.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 2012-01-01 false Interlocking relationships permitted pursuant to...MANAGEMENT OFFICIAL INTERLOCKS § 196.9 Interlocking relationships permitted pursuant to...may enter into an otherwise prohibited interlocking relationship with another...

  10. 12 CFR 196.9 - Interlocking relationships permitted pursuant to Federal Deposit Insurance Act.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 2014-01-01 false Interlocking relationships permitted pursuant to...MANAGEMENT OFFICIAL INTERLOCKS § 196.9 Interlocking relationships permitted pursuant to...may enter into an otherwise prohibited interlocking relationship with another...

  11. 12 CFR 390.408 - Interlocking relationships permitted pursuant to Federal Deposit Insurance Act.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 2013-01-01 false Interlocking relationships permitted pursuant to...Official Interlocks § 390.408 Interlocking relationships permitted pursuant to...enter into an otherwise prohibited interlocking relationship with another...

  12. 12 CFR 238.99 - Interlocking relationships permitted pursuant to Federal Deposit Insurance Act.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 2012-01-01 false Interlocking relationships permitted pursuant to...Official Interlocks § 238.99 Interlocking relationships permitted pursuant to...enter into an otherwise prohibited interlocking relationship with another...

  13. 12 CFR 238.99 - Interlocking relationships permitted pursuant to Federal Deposit Insurance Act.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 2014-01-01 false Interlocking relationships permitted pursuant to...Official Interlocks § 238.99 Interlocking relationships permitted pursuant to...enter into an otherwise prohibited interlocking relationship with another...

  14. Influence of screw length and diameter on tibial strain energy density distribution after anterior cruciate ligament reconstruction

    NASA Astrophysics Data System (ADS)

    Yao, Jie; Kuang, Guan-Ming; Wong, Duo Wai-Chi; Niu, Wen-Xin; Zhang, Ming; Fan, Yu-Bo

    2014-04-01

    Postoperative tunnel enlargement has been frequently reported after anterior cruciate ligament (ACL) reconstruction. Interference screw, as a surgical implant in ACL reconstruction, may influence natural loading transmission and contribute to tunnel enlargement. The aims of this study are (1) to quantify the alteration of strain energy den sity (SED) distribution after the anatomic single-bundle ACL reconstruction; and (2) to characterize the influence of screw length and diameter on the degree of the SED alteration. A validated finite element model of human knee joint was used. The screw length ranging from 20 to 30mm with screw diameter ranging from 7 to 9 mm were investigated. In the post-operative knee, the SED increased steeply at the extra-articular tunnel aperture under compressive and complex loadings, whereas the SED decreased beneath the screw shaft and nearby the intra-articular tunnel aperture. Increasing the screw length could lower the SED deprivation in the proximal part of the bone tunnel; whereas increasing either screw length or diameter could aggravate the SED deprivation in the distal part of the bone tunnel. Decreasing the elastic modulus of the screw could lower the bone SED deprivation around the screw. In consideration of both graft stability and SED alteration, a biodegradable interference screw with a long length is recommended, which could provide a beneficial mechanical environment at the distal part of the tunnel, and meanwhile decrease the bone-graft motion and synovial fluid propagation at the proximal part of the tunnel. These findings together with the clinical and histological factors could help to improve surgical outcome, and serve as a preliminary knowledge for the following study of biodegradable interference screw. [Figure not available: see fulltext.

  15. An Innovative Universal Screw Removal Instrument

    PubMed Central

    Elmada?, Mehmet; Uzer, Gökçer; Acar, Mehmet Ali

    2015-01-01

    Objective To present the clinical benefits of an instrument designed to facilitate removal of polyaxial screws during revision surgery. Methods All polyaxial screws can be removed without additional materials or a large amount of debridement using our newly designed instrument. Forty-two screws were removed from five patients without any complications using this instrument. Results We removed the cap screws and rods from the 42 polyaxial screws in five patients and made them monoaxial using the new screw removal apparatus. The screws and rods were removed quickly in a minimally invasive way with no complications. No damage to the pedicle or surrounding soft tissue occurred during screw removal. No neurogenic changes developed during revision surgery after changing the screws. Conclusion This newly designed screw removal instrument was used safely and effectively to remove all polyaxial and monoaxial pedicle screws.

  16. 9. VIEW, LOOKING SOUTH, OF INTERLOCKING MACHINE, WITH ORIGINAL MODEL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. VIEW, LOOKING SOUTH, OF INTERLOCKING MACHINE, WITH ORIGINAL MODEL BOARD IN CENTER, NEW MODEL BOARD AT LEFT AND MODEL SEMAPHORES AT TOP OF PHOTOGRAPH, THIRD FLOOR - South Station Tower No. 1 & Interlocking System, Dewey Square, Boston, Suffolk County, MA

  17. 8. INTERIOR DETAIL, SECOND STORY, SHOWING INTERLOCKING MACHINE CONSOLE AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. INTERIOR DETAIL, SECOND STORY, SHOWING INTERLOCKING MACHINE CONSOLE AND TRACK BOARD - Baltimore & Potomac Interlocking Tower, Adjacent to AMTRAK railroad tracks in block bounded by Howard Street, Jones Falls Expressway, Maryland Avenue & Falls Road, Baltimore, Independent City, MD

  18. 3. General view showing north elevation of Shell Interlocking Tower ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. General view showing north elevation of Shell Interlocking Tower and electric relay station. - New York, New Haven, & Hartford Railroad, Shell Interlocking Tower, New Haven Milepost 16, approximately 100 feel east of New Rochelle Junction, New Rochelle, Westchester County, NY

  19. 8. VIEW, LOOKING NORTH, OF INTERLOCKING MACHINE WITH ORIGINAL MODEL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. VIEW, LOOKING NORTH, OF INTERLOCKING MACHINE WITH ORIGINAL MODEL BOARD IN CENTER AND MODEL SEMAPHORE SIGNALS (AT TOP OF PHOTOGRAPH), THIRD FLOOR - South Station Tower No. 1 & Interlocking System, Dewey Square, Boston, Suffolk County, MA

  20. Mechanically interlocked DNA nanostructures for functional devices.

    PubMed

    Jester, Stefan-S; Famulok, Michael

    2014-06-17

    CONSPECTUS: Self-assembled functional DNA oligonucleotide based architectures represent highly promising candidates for the creation of nanoscale devices. The field of DNA nanotechnology has emerged to a high level of maturity and currently constitutes one of the most dynamic, creative, and exciting modern research areas. The transformation from structural DNA nanotechnology to functional DNA architectures is already taking place with tremendous pace. Particularly the advent of DNA origami technology has propelled DNA nanotechnology forward. DNA origami provided a versatile method for precisely aligning structural and functional DNA modules in two and three dimensions, thereby serving as a means for constructing scaffolds and chassis required for the precise orchestration of multiple functional DNA architectures. Key modules of these will contain interlocked nanomechanical components made of DNA. The mechanical interlocking allows for performing highly specific and controlled motion, by reducing the dimensionality of diffusion-controlled processes without restrictions in motional flexibility. Examples for nanoscale interlocked DNA architectures illustrate how elementary functional units of future nanomachines can be designed and realized, and show what role interlocked DNA architectures may play in this endeavor. Functional supramolecular systems, in general, and nanomachinery, in particular, self-organize into architectures that reflect different levels of complexity with respect to their function, their arrangement in the second and third dimension, their suitability for different purposes, and their functional interplay. Toward this goal, DNA nanotechnology and especially the DNA origami technology provide opportunities for nanomechanics, nanorobotics, and nanomachines. In this Account, we address approaches that apply to the construction of interlocked DNA nanostructures, drawing largely form our own contributions to interlocked architectures based on double-stranded (ds) circular geometries, and describe progress, opportunities, and challenges in rotaxanes and pseudorotaxanes made of dsDNA. Operating nanomechanical devices in a reliable and repetitive fashion requires methods for switching movable parts in DNA nanostructures from one state to another. An important issue is the orthogonality of switches that allow for operating different parts in parallel under spatiotemporal control. A variety of switching methods have been applied to switch individual components in interlocked DNA nanostructures like rotaxanes and catenanes. They are based on toehold, light, pseudocomplementary peptide nucleic acids (pcPNAs), and others. The key issues discussed here illustrate our perspective on the future prospects of interlocked DNA-based devices and the challenges that lay ahead. PMID:24627986

  1. Carbon nanotube Archimedes screws.

    PubMed

    Oroszlány, László; Zólyomi, Viktor; Lambert, Colin J

    2010-12-28

    Recently, nanomechanical devices composed of a long stationary inner carbon nanotube and a shorter, slowly rotating outer tube have been fabricated. In this paper, we study the possibility of using such devices as nanoscale transducers of motion into electricity. When the outer tube is chiral, we show that such devices act like quantum Archimedes screws, which utilize mechanical energy to pump electrons between reservoirs. We calculate the pumped charge from one end of the inner tube to the other, driven by the rotation of a chiral outer nanotube. We show that the pumped charge can be greater than one electron per 360° rotation, and consequently, such a device operating with a rotational frequency of 10 MHz, for example, would deliver a current of ?1 pAmp. PMID:21126086

  2. The screw propeller

    NASA Astrophysics Data System (ADS)

    Larrabee, E. E.

    1980-07-01

    Marine and air screw propellers are considered in terms of theoretical hydrodynamics as developed by Joukowsky, Prandtl, and Betz. Attention is given to the flow around wings of finite span where spanwise flow exists and where lift and the bound vorticity must all go smoothly to zero at the wing tips. The concept of a trailing vortex sheet made up of infinitesimal line vortexes roughly aligned with the direction of flight is discussed in this regard. Also considered is induced velocity, which tends to convect the sheet downward at every stage in the roll-up process, the vortex theory of propellers and the Betz-Prandtl circulation distribution. The performance of the Gossamer Albatross and of a pedal-driven biplane called the Chrysalis are also discussed.

  3. Automated Verification of Signalling Principles in Railway Interlocking Systems1

    E-print Network

    Moller, Faron G.

    Automated Verification of Signalling Principles in Railway Interlocking Systems1 Karim Kanso2 Faron present a verification strategy for signalling principles for the control of a railway interlock- ing-world example of a railway interlocking system. The steps in this translation are as follows: 1. The development

  4. Simulation and Verification of UML-based Railway Interlocking Designs

    E-print Network

    Paris-Sud XI, Université de

    AVoCS 2006 Simulation and Verification of UML-based Railway Interlocking Designs Yuen Man Hon1 Maik Abstract The development of safety critical systems such as railway interlocking systems demands. In this contribution we outline our approach of developing a UML-based Railway Interlocking System. The feasibility

  5. Interlocked Open Linkages with Few Joints Erik D. Demaine

    E-print Network

    Demaine, Erik

    Interlocked Open Linkages with Few Joints Erik D. Demaine MIT LCS Cambridge, MA edemaine linkages in 3- space that may be interlocked in the sense that the link- ages cannot be separated without at least d. If a collection cannot be separated, we say that its chains are interlocked. In this paper, we

  6. EURIS, a Speci cation Method for Distributed Interlockings

    E-print Network

    Grant, P. W.

    EURIS, a Speci cation Method for Distributed Interlockings Fokko van Dijkx Wan Fokkink? Gea Kolkx approach to the speci cation of interlocking logics. We also give an overview of UniSpec, which is an instance of EURIS for the Dutch railway system. KEY WORDS: interlocking logic; safety critical; distributed

  7. Simulated Time for Testing Railway Interlockings with TTCN-3

    E-print Network

    Sidorova, Natalia

    Simulated Time for Testing Railway Interlockings with TTCN-3 Stefan Blom1 , Natalia Ioustinova1 time, scaled time, simulated time, interlockings, TTCN-3. 1 Introduction Railway control systems. The interlocking is a layer of rail- way control systems that guarantees safety. It allows to execute commands

  8. Predicting repeat DUI offenses with the alcohol interlock recorder

    Microsoft Academic Search

    Paul R Marques; A. Scott Tippetts; Robert B Voas; Douglas J Beirness

    2001-01-01

    The aim of this report has been to use information contained in the alcohol ignition interlock recorder to determine whether systematic analysis of it can be used to predict which DUI offenders will recidivate during the first 2 years after the interlock is removed. The interlock record was accumulated during a 4-year intervention study in Alberta, Canada. Data from more

  9. Simulated Time for Testing Railway Interlockings with TTCN-3

    E-print Network

    Middeldorp, Aart

    Simulated Time for Testing Railway Interlockings with TTCN-3 Stefan Blom1 , Natalia Ioustinova2, scaled time, simulated time, interlockings, TTCN-3. 1 Introduction Railway control systems are safety-critical and therefore we have to ensure that they are designed and implemented correctly. The interlocking is a layer

  10. Homogenization of interlocking masonry structures using a generalized differential

    E-print Network

    Paris-Sud XI, Université de

    1 Homogenization of interlocking masonry structures using a generalized differential expansion://navier.enpc.fr/~sulem/index.html Keywords: Micromorphic Continuum; Interlocking masonry; Wave propagation; Generalized Differential for the homogenization of masonry structures with interlocking blocks. This is done by constructing a continuum which

  11. Interlocked Open Linkages with Few Joints Erik D. Demaine

    E-print Network

    O'Rourke, Joseph

    Interlocked Open Linkages with Few Joints Erik D. Demaine Stefan Langerman Joseph O'Rourke Jack that may be interlocked in the sense that the linkages cannot be separated without one bar crossing through and explore the smallest number of chains and bars needed to achieve interlock. Whereas previous work used

  12. Interlocked Open and Closed Linkages with Few Joints

    E-print Network

    Demaine, Erik

    Interlocked Open and Closed Linkages with Few Joints Erik D. Demaine MIT Laboratory for Computer of linkages in 3-space that are interlocked in the sense that the linkages cannot be separated without one bar with a small number of joints, and determine which can be interlocked. In particular, we show that a triangle

  13. Interlocked Open Linkages with Few Joints # Erik D. Demaine

    E-print Network

    Langerman, Stefan

    Interlocked Open Linkages with Few Joints # Erik D. Demaine MIT LCS Cambridge, MA edemaine linkages in 3­ space that may be interlocked in the sense that the link­ ages cannot be separated without at least d. If a collection cannot be separated, we say that its chains are interlocked. In this paper, we

  14. 1. INTRODUCTION Today critical systems like railway station interlocking sys-

    E-print Network

    Firenze, Università degli Studi di

    1. INTRODUCTION Today critical systems like railway station interlocking sys- tems employed in all of a railway interlocking Andrea Bondavalli*, Manuela Nelli¶, Luca Simoncini and Giorgio Mongardi§ *DIS the dependability of an actual railway station interlocking control system. Despite our analysis has been restricted

  15. BaBar Note 323 Temperature Monitoring and Interlocks

    E-print Network

    BaBar Note 323 Temperature Monitoring and Interlocks for the BaBar SVT Front-End Electronics David of the temperature mon- itoring and interlocks system for the front-end hybrid HDI circuits of the BaBar silicon not cover tempera- ture monitoring for other SVT systems, or other signals that interlock the SVT power

  16. Verification of Interlockings: from Control Tables to Ladder Logic Diagrams

    E-print Network

    Fokkink, Wan

    Verification of Interlockings: from Control Tables to Ladder Logic Diagrams Wan Fokkink and Paul in a railway yard are tabulated in control tables. An interlocking, which guarantees validity; that is, collisions and derailments have to be avoided. This is done by means of an interlocking, which

  17. Wear and corrosion of sliding counterparts of stainless-steel hip screw-plates.

    PubMed

    Shahgaldi, B F; Compson, J

    2000-03-01

    Wear of the lag screw and barrel of stainless-steel sliding hip screw-plates (SHSP) produces particles and corrosion that jam the sliding screw. This alters the mechanics of the SHSP causing failure and difficulty in removal. We examined 15 surgically-removed SHSP for the extent of wear and corrosion of metal, and damage to the surrounding tissue. SHSP implants were in place from 2 months to 11 years (average 38.9 months) and they were removed because of fracture non-union, implant fracture or pain. None was infected. Electron microscopy was used to examine the implant surfaces and to determine the chemistry of corrosion products both on the metal and in the tissue. The distal ends of all the lag screws and inside walls of the barrels showed wear and corrosion. The severity of corrosion increased with increasing duration of implant use. Surfaces of the inside walls of the barrels were rough from the manufacturing process. This had contributed to wear. Better manufacturing practice to improve surface smoothness of the lag screws and inside wall of the barrels is needed. Use of cobalt-chromium alloys would improve hardness and resistance to corrosion compared with the stainless steel presently used, which would be an advantage for sliding hip screw-plates in younger patients. Deliberate texturing of screws is counter productive and should be avoided. PMID:10748810

  18. Efficiency of a pendulum appliance for molar distalization related to second and third molar eruption stage

    Microsoft Academic Search

    Gero S. M Kinzinger; Ulrike B Fritz; Franz-Günter Sander; Peter R Diedrich

    2004-01-01

    A modified pendulum appliance, including a distal screw and special preactivated pendulum springs (built-in straightening activation and toe-in bending), was used for bilateral maxillary molar distalization in 36 adolescent patients in various stages of the molar dentition. The patients were divided into 3 groups (PG 1-3) according to the stage of eruption of their second and third molars. In PG

  19. Process synchronization without long-term interlock

    Microsoft Academic Search

    William B. Easton

    1971-01-01

    A technique is presented for replacing long-term interlocking of shared data by the possible repetition of unprivileged code in case a version number (associated with the shared data) has been changed by another process. Four principles of operating system architecture (which have desirable effects on the intrinsic reliability of a system) are presented; implementation of a system adhering to these

  20. Process synchronization without long-term interlock

    Microsoft Academic Search

    William B. Easton

    1972-01-01

    A technique is presented for replacing long-term interlocking of shared data by the possible repetition of unprivileged code in case a version number (associated with the shared data) has been changed by another process. Four principles of operating system architecture (which have desirable effects on the intrinsic reliability of a system) are presented; implementation of a system adhering to these

  1. Robotic Distal Pancreatectomy

    PubMed Central

    Rutledge, John; Yiengpruksawan, Anusak

    2013-01-01

    Background: A robotic-assisted minimal invasive approach has the potential to overcome the limitations of conventional laparoscopic pancreatectomies. We analyzed the outcomes of robotic-assisted distal pancreatectomies (RDPs) to demonstrate the safety and feasibility of robotic distal pancreas resection, including spleen preservation. Methods: We performed a descriptive retrospective analysis of 40 RDPs. Statistical comparisons were performed between two groups of patients undergoing robotic-assisted spleen-preserving distal pancreatectomy (SPDP) and distal pancreatectomy with splenectomy (SDP). Survival analysis was performed using the Kaplan-Meier method. Results: Of 49 attempted RDPs, 40 were completed with robotic assistance, with a conversion rate of 18.4%. Compared with the published reports of laparoscopic distal pancreatotomy (DP) and robotic DP, the spleen preservation rate (30%), operating time (203 minutes), major complications rate (5%), fistula rate (20%), and length of hospital stay (5 days) were similar in our RDP patients. Also, the perioperative outcomes of the SPDP and SDP groups did not differ significantly. The median survival was 12.5 months for the patients undergoing RDP for pancreatic ductal adenocarcinoma. Conclusions: Robotic-assisted distal pancreatectomy, with or without splenic preservation, can be safely performed for lesions of the distal pancreas, with appropriate indications. PMID:24398207

  2. Distal movement of mandibular molars in adult patients with the skeletal anchorage system

    Microsoft Academic Search

    Junji Sugawara; Takayoshi Daimaruya; Mikako Umemori; Hiroshi Nagasaka; Ichiro Takahashi; Hiroshi Kawamura; Hideo Mitani

    2004-01-01

    The skeletal anchorage system (SAS) consists of titanium anchor plates and monocortical screws that are temporarily placed in either the maxilla or the mandible, or in both, as absolute orthodontic anchorage units. Distalization of the molars has been one of the most difficult biomechanical problems in traditional orthodontics, particularly in adults and in the mandible. However, it has now become

  3. Mechanically interlocked single-wall carbon nanotubes.

    PubMed

    de Juan, Alberto; Pouillon, Yann; Ruiz-González, Luisa; Torres-Pardo, Almudena; Casado, Santiago; Martín, Nazario; Rubio, Ángel; Pérez, Emilio M

    2014-05-19

    Extensive research has been devoted to the chemical manipulation of carbon nanotubes. The attachment of molecular fragments through covalent-bond formation produces kinetically stable products, but implies the saturation of some of the C-C double bonds of the nanotubes. Supramolecular modification maintains the structure of the SWNTs but yields labile species. Herein, we present a strategy for the synthesis of mechanically interlocked derivatives of SWNTs (MINTs). In the key rotaxane-forming step, we employed macrocycle precursors equipped with two ?-extended tetrathiafulvalene SWNT recognition units and terminated with bisalkenes that were closed around the nanotubes through ring-closing metathesis (RCM). The mechanically interlocked nature of the derivatives was probed by analytical, spectroscopic, and microscopic techniques, as well as by appropriate control experiments. Individual macrocycles were observed by HR?STEM to circumscribe the nanotubes. PMID:24729452

  4. Thermal static bending of deployable interlocked booms

    NASA Technical Reports Server (NTRS)

    Staugaitis, C. L.; Predmore, R. E.

    1973-01-01

    Metal ribbons processed with a heat-forming treatment are enabled to form tubelike structures when deployed from a roll. Deployable booms of this have been utilized for gravity-gradient stabilization on the RAE, ATS, and Nimbus D satellites. An experimental thermal-mechanics test apparatus was developed to measure the thermal static bending and twist of booms up to 3 meters long. The apparatus was calibrated by using the correlation between calculated and observed thermal bending of a seamless tube. Thermal static bending values of 16 interlocked deployable booms were observed to be within a factor of 2.5 of the values calculated from seamless-tube theory. Out-of-Sun-plane thermal bending was caused by complex heat transfer across the interlocked seam. Significant thermal static twisting was not observed.

  5. Interlocking egg-crate type grid assembly

    SciTech Connect

    Kast, S.J.

    1987-12-22

    A spacer grid assembly for supporting nuclear fuel pins in a closely-spaced array is described comprising: (a) a first grid strip comprising segments, disposed at an angle to each other with alternate segments being substantially parallel to each other, each of the segments carrying at least one dimple for contacting the fuel pins; (b) a second grid strip comprising segments disposed at an angle to each other with alternate segments being substantially parallel to each other, each alternate segment of the second strip carrying a resilient contact for contacting the fuel pins; (c) a third grid strip comprising segments disposed at an angle to each other with alternate segments being substantially parallel to each other, each of the segments of the third strip carrying at least one dimple for contacting the fuel pins; and (d) interlocking means formed on the grid strips for interlocking the first and third grid strips with the second grid strip to form an array of grid cells having a hexagonal cross section and the segments of the first and third grid strips are substantially coplanar. The locking means include first tabs positioned on alternate segments of the first and third grid strips for interlocking with first slots formed on other alternate segments of the second grid strips that do not carry the resilient contacts.

  6. Construction and Biomechanical Properties of PolyAxial Self-Locking Anatomical Plate Based on the Geometry of Distal Tibia

    PubMed Central

    Liang, Weiguo; Ye, Weixiong; Ye, Dongping; Zhou, Ziqiang; Chen, Zhiguang; Li, Aiguo; Xie, Zong-Han; Zhang, Lihai; Xu, Jiake

    2014-01-01

    In order to provide scientific and empirical evidence for the clinical application of the polyaxial self-locking anatomical plate, 80 human tibias from healthy adults were scanned by spiral CT and their three-dimensional images were reconstructed using the surface shaded display (SSD) method. Firstly, based on the geometric data of distal tibia, a polyaxial self-locking anatomical plate for distal tibia was designed and constructed. Biomechanical tests were then performed by applying axial loading, 4-point bending, and axial torsion loading on the fracture fixation models of fresh cadaver tibias. Our results showed that variation in twisting angles of lateral tibia surface was found in various segments of the distal tibia. The polyaxial self-locking anatomical plate was constructed based on the geometry of the distal tibia. Compared to the conventional anatomical locking plate, the polyaxial self-locking anatomical plate of the distal tibia provides a better fit to the geometry of the distal tibia of the domestic population, and the insertion angle of locking screws can be regulated up to 30°. Collectively, this study assesses the geometry of the distal tibia and provides variable locking screw trajectory to improve screw-plate stability through the design of a polyaxial self-locking anatomical plate. PMID:25025051

  7. An Articulating Tool for Endoscopic Screw Delivery

    E-print Network

    Petrzelka, Joseph Edward

    This paper describes the development of an articulating endoscopic screw driver that can be used to place screws in osteosynthetic plates during thoracoscopic surgery. The device is small enough to be used with a 12 mm ...

  8. High-Performance 3-1 Interlock Collapsing ALU's

    Microsoft Academic Search

    James Phillips; Stamatis Vassiliadis

    1994-01-01

    A high-performance 3-1 interlock collapsing ALU, i.e., an ALU that allows the execution of most execution interlocks in a single machine cycle, is presented. We focus on reducing the Boolean equations describing the device and the incorporation of new mechanisms in the interlock collapsing ALU design. In particular, we focus on the reduction of the critical path, regarding delay, for

  9. A 2-CHAIN CAN INTERLOCK WITH AN OPEN 11-CHAIN

    E-print Network

    O'Rourke, Joseph

    A 2-CHAIN CAN INTERLOCK WITH AN OPEN 11-CHAIN JULIE GLASS, BIN LU, JOSEPH O'ROURKE, AND JIANYUAN K-chain can interlock with a flexible 2-chain. It was conjectured in [3] that the minimal k satisfies 6 k 11 this result to k 11 by proving that a flexible 2-chain can interlock with a flexible, open 11-chain. We offer

  10. The single screw extrusion of pastes

    Microsoft Academic Search

    A. S. Burbidge; J. Bridgwater

    1995-01-01

    Screw extrusion is widely used but little is known about the design and operation of this type of equipment save in the polymer industry. Particularly with the advent of high-performance, high-value ceramic materials, it has become important to extend knowledge. Here a mathematical model for a flooded screw brings together recent paste rheology and a model of screw extrusion developed

  11. Rotary screw compressors in the gas patch

    Microsoft Academic Search

    Jandjel

    1996-01-01

    In 1959, Howden introduced the oil-injected rotary screw (OIS) compressor, which has, since then, methodically replaced the reciprocating (piston) compressor in applications such as air, refrigeration and fuel gas. Rotary screw compressors have been making inroads in gas recovery, a field once dominated by reciprocating compressors. Rotary screws do not require extensive maintenance, thus downtime is minimized throughout an operating

  12. 21 CFR 876.4590 - Interlocking urethral sound.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Surgical Devices § 876.4590 Interlocking urethral sound. (a) Identification. An...

  13. 21 CFR 876.4590 - Interlocking urethral sound.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Surgical Devices § 876.4590 Interlocking urethral sound. (a) Identification. An...

  14. 21 CFR 876.4590 - Interlocking urethral sound.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Surgical Devices § 876.4590 Interlocking urethral sound. (a) Identification. An...

  15. 21 CFR 876.4590 - Interlocking urethral sound.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Surgical Devices § 876.4590 Interlocking urethral sound. (a) Identification. An...

  16. 21 CFR 876.4590 - Interlocking urethral sound.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Surgical Devices § 876.4590 Interlocking urethral sound. (a) Identification. An...

  17. Active Template Strategies for the Assembly of Mechanically Interlocked Molecules 

    E-print Network

    Ronaldson, Vicki E

    2009-01-01

    Chemical templates have allowed the synthesis of increasingly complex mechanically interlocked molecular architectures. Transition metals are useful templating agents. Their coordination requirements result in the ...

  18. 49 CFR 236.312 - Movable bridge, interlocking of signal appliances with bridge devices.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Movable bridge, interlocking of signal appliances with bridge devices. 236.312 Section 236.312...Interlocking Standards § 236.312 Movable bridge, interlocking of signal appliances with...

  19. 12 CFR 250.411 - Interlocking relationships between member bank and variable annuity insurance company.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 2014-01-01 false Interlocking relationships between member bank...Glass-Steagall Act § 250.411 Interlocking relationships between member bank...S.C. 78) and this part prohibit interlocking service between member banks...

  20. 12 CFR 250.411 - Interlocking relationships between member bank and variable annuity insurance company.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 2013-01-01 false Interlocking relationships between member bank...Glass-Steagall Act § 250.411 Interlocking relationships between member bank...S.C. 78) and this part prohibit interlocking service between member banks...

  1. 12 CFR 250.411 - Interlocking relationships between member bank and variable annuity insurance company.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 2012-01-01 false Interlocking relationships between member bank...Glass-Steagall Act § 250.411 Interlocking relationships between member bank...S.C. 78) and this part prohibit interlocking service between member banks...

  2. 20. VIEW OF NEWER 7LEVER INTERLOCKING MACHINE IN FOREGROUND, NEXT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. VIEW OF NEWER 7-LEVER INTERLOCKING MACHINE IN FOREGROUND, NEXT TO ORIGINAL INTERLOCKING MACHINE, THIRD FLOOR - South Station Tower No. 1 & Interlocking System, Dewey Square, Boston, Suffolk County, MA

  3. 12 CFR 250.411 - Interlocking relationships between member bank and variable annuity insurance company.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 2011-01-01 false Interlocking relationships between member bank...Glass-Steagall Act § 250.411 Interlocking relationships between member bank...S.C. 78) and this part prohibit interlocking service between member banks...

  4. 18 CFR 131.31 - FERC Form No. 561, Annual report of interlocking positions.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...FERC Form No. 561, Annual report of interlocking positions. 131.31 Section 131...FERC Form No. 561, Annual report of interlocking positions. (See section 46.4...INSTRUCTIONS FOR COMPLETING ANNUAL REPORT OF INTERLOCKING POSITIONS GENERAL INFORMATION:...

  5. 18 CFR 131.31 - FERC Form No. 561, Annual report of interlocking positions.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...FERC Form No. 561, Annual report of interlocking positions. 131.31 Section 131...FERC Form No. 561, Annual report of interlocking positions. (See section 46.4...INSTRUCTIONS FOR COMPLETING ANNUAL REPORT OF INTERLOCKING POSITIONS GENERAL INFORMATION:...

  6. 18 CFR 131.31 - FERC Form No. 561, Annual report of interlocking positions.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...FERC Form No. 561, Annual report of interlocking positions. 131.31 Section 131...FERC Form No. 561, Annual report of interlocking positions. (See section 46.4...INSTRUCTIONS FOR COMPLETING ANNUAL REPORT OF INTERLOCKING POSITIONS GENERAL INFORMATION:...

  7. 46 CFR 111.91-1 - Power, control, and interlock circuits.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...false Power, control, and interlock...ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Elevators and Dumbwaiters...91-1 Power, control, and interlock...electric power, control, and interlock circuit of an elevator or...

  8. 46 CFR 111.91-1 - Power, control, and interlock circuits.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...false Power, control, and interlock...ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Elevators and Dumbwaiters...91-1 Power, control, and interlock...electric power, control, and interlock circuit of an elevator or...

  9. 46 CFR 111.91-1 - Power, control, and interlock circuits.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...false Power, control, and interlock...ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Elevators and Dumbwaiters...91-1 Power, control, and interlock...electric power, control, and interlock circuit of an elevator or...

  10. 46 CFR 111.91-1 - Power, control, and interlock circuits.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...false Power, control, and interlock...ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Elevators and Dumbwaiters...91-1 Power, control, and interlock...electric power, control, and interlock circuit of an elevator or...

  11. 46 CFR 111.91-1 - Power, control, and interlock circuits.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...false Power, control, and interlock...ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Elevators and Dumbwaiters...91-1 Power, control, and interlock...electric power, control, and interlock circuit of an elevator or...

  12. All Screwed Up : A Memoir

    Microsoft Academic Search

    Steven Fellner

    2009-01-01

    Murder attempts... missing umbilical cords... haunted quarries... fat camps... These darkly comic stories fill the pages of All Screwed Up. Young, gay, and poor, Steve Fellner attempts to shed his trailer park past and seize a better life for himself. But coming from the sticks offers a certain kind of freedom: no one expects anything from you, so you can

  13. The influence of distal locking on the need for fibular plating in intramedullary nailing of distal metaphyseal tibiofibular fractures.

    PubMed

    Attal, R; Maestri, V; Doshi, H K; Onder, U; Smekal, V; Blauth, M; Schmoelz, W

    2014-03-01

    Using human cadaver specimens, we investigated the role of supplementary fibular plating in the treatment of distal tibial fractures using an intramedullary nail. Fibular plating is thought to improve stability in these situations, but has been reported to have increased soft-tissue complications and to impair union of the fracture. We proposed that multidirectional locking screws provide adequate stability, making additional fibular plating unnecessary. A distal tibiofibular osteotomy model performed on matched fresh-frozen lower limb specimens was stabilised with reamed nails using conventional biplanar distal locking (CDL) or multidirectional distal locking (MDL) options with and without fibular plating. Rotational stiffness was assessed under a constant axial force of 150 N and a superimposed torque of ± 5 Nm. Total movement, and neutral zone and fracture gap movement were analysed. In the CDL group, fibular plating improved stiffness at the tibial fracture site, albeit to a small degree (p = 0.013). In the MDL group additional fibular plating did not increase the stiffness. The MDL nail without fibular plating was significantly more stable than the CDL nail with an additional fibular plate (p = 0.008). These findings suggest that additional fibular plating does not improve stability if a multidirectional distal locking intramedullary nail is used, and is therefore unnecessary if not needed to aid reduction. PMID:24589796

  14. Metallurgical examination of gun barrel screws

    SciTech Connect

    Bird, E.L.; Clift, T.L.

    1996-06-01

    The examination was conducted to determine the extent of degradation that had occurred after a series of firings; these screws prevent live rounds of ammunition from being loaded into the firing chamber. One concern is that if the screw tip fails and a live round is accidentally loaded into the chamber, a live round could be fired. Another concern is that if the blunt end of the screw begins to degrade by cracking, pieces could become small projectiles during firing. All screws used in firing 100 rounds or more exhibited some degree degradation, which progressively worsened as the number of rounds fired increased. (SEM, metallography, x-ray analysis, and microhardness were used.) Presence of cracks in these screws after 100 fired rounds is a serious concern that warrants the discontinued use of these screws. The screw could be improved by selecting an alloy more resistant to thermal and chemical degradation.

  15. Design for assembly : a computational approach to construct interlocking wooden frames

    E-print Network

    Tai, Alan Song-Ching

    2012-01-01

    This thesis explores the computational process of generating and constructing interlocking frames. Its outcome delivers a sophisticated software tool that creates a three dimensional interlocking pattern, analyzes the ...

  16. [Tendon rupture as a complication after osteosynthesis of distal radius].

    PubMed

    Lugger, L J; Pechlaner, S

    1984-10-01

    Close contact between extensor and flexor tendons to the bone structure of the wrist and distal radius shaft implies the possibility of alteration concerning the tendons' slide way and tensile direction in case of osteosynthesis in this region. Even a slightly damaged screw is mechanically capable of irritation and can be made responsible for a scrub-necrosis of an above tendon. The metal implant has to be selected in consideration of both the demands of the fracture and a free and natural tendons pathway. This is discussed by means of two implant-induced scrub necroses of the long pollex extensor and flexor tendon. PMID:6516033

  17. Administrative Reinstatement Interlock Programs: Florida, a 10-Year Study

    PubMed Central

    Voas, Robert B.; Tippetts, A. Scott; Grosz, Milton

    2013-01-01

    Background Interlocks reduce driving-under-the-influence (DUI) recidivism by 64%, but offenders resist installing them, preferring to risk driving while their driver’s licenses are revoked. One method of motivating offenders to install an interlock is require it for reinstatement of their driver’s license. This report updates an earlier evaluation of the administrative reinstatement interlock program (ARIP) procedure implemented in Florida in 2002. Method Driver records and interlock program records covering 120,000 DUI offenders were followed over 10 years. The flow through the sanction system—conviction, reinstatement, interlock program, and postinterlock period—is described. Logistical regression was used to identify the characteristics of offenders who installed interlocks, and survival analysis was used to evaluate the recidivism of offenders in the various stages in the ARIP. Results At any given time, approximately one third of the convicted offenders were serving their license-revocation periods. Half of the offenders who completed their revocation periods remain unqualified for reinstatement because they do not fulfill other requirements. ARIP offenders who do qualify for reinstatement and install interlocks have lower recidivism rates while the devices are on their vehicles. Conclusions After 10 years, Florida’s ARIP is a mature system that succeeds in forcing all offenders in the program who qualify for reinstatement to install an interlock for at least 6 months. However, half of all offenders who complete their mandatory revocation period are either unable to, or choose not to, qualify for reinstatement. PMID:23442206

  18. 12 CFR 303.249 - Management official interlocks.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...establish an interlock pursuant to the Depository Institutions Management Interlocks Act (12 U.S.C. 3207), section 13 of the FDI Act (12 U.S.C. 1823(k)) and part 348 of this chapter (12 CFR part 348). (b) Where to file. Applicants...

  19. 12 CFR 196.4 - Interlocking relationships permitted by statute.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...false Interlocking relationships permitted by statute...4 Interlocking relationships permitted by statute...3 do not apply in the case of any...to service as a single management official...association, by a single management official...the stock issued in connection...

  20. 12 CFR 563f.4 - Interlocking relationships permitted by statute.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...false Interlocking relationships permitted by statute...4 Interlocking relationships permitted by statute...3 do not apply in the case of any...to service by a single management official...holding company, by a single management official...the stock issued in connection...

  1. 12 CFR 563f.4 - Interlocking relationships permitted by statute.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...false Interlocking relationships permitted by statute...4 Interlocking relationships permitted by statute...3 do not apply in the case of any...to service by a single management official...holding company, by a single management official...the stock issued in connection...

  2. 12 CFR 196.4 - Interlocking relationships permitted by statute.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...false Interlocking relationships permitted by statute...4 Interlocking relationships permitted by statute...3 do not apply in the case of any...to service as a single management official...association, by a single management official...the stock issued in connection...

  3. 12 CFR 238.94 - Interlocking relationships permitted by statute.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...false Interlocking relationships permitted by statute...94 Interlocking relationships permitted by statute...93 do not apply in the case of any...to service by a single management official...holding company, by a single management official...the stock issued in connection...

  4. 12 CFR 196.4 - Interlocking relationships permitted by statute.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...false Interlocking relationships permitted by statute...4 Interlocking relationships permitted by statute...3 do not apply in the case of any...to service as a single management official...association, by a single management official...the stock issued in connection...

  5. 12 CFR 390.403 - Interlocking relationships permitted by statute.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...false Interlocking relationships permitted by statute...403 Interlocking relationships permitted by statute...402 do not apply in the case of any...to service as a single management official...association by a single management official...the stock issued in connection...

  6. 12 CFR 238.94 - Interlocking relationships permitted by statute.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...false Interlocking relationships permitted by statute...94 Interlocking relationships permitted by statute...93 do not apply in the case of any...to service by a single management official...holding company, by a single management official...the stock issued in connection...

  7. 12 CFR 390.403 - Interlocking relationships permitted by statute.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...false Interlocking relationships permitted by statute...403 Interlocking relationships permitted by statute...402 do not apply in the case of any...to service as a single management official...association by a single management official...the stock issued in connection...

  8. 12 CFR 390.403 - Interlocking relationships permitted by statute.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...false Interlocking relationships permitted by statute...403 Interlocking relationships permitted by statute...402 do not apply in the case of any...to service as a single management official...association by a single management official...the stock issued in connection...

  9. 12 CFR 563f.4 - Interlocking relationships permitted by statute.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...false Interlocking relationships permitted by statute...4 Interlocking relationships permitted by statute...3 do not apply in the case of any...to service by a single management official...holding company, by a single management official...the stock issued in connection...

  10. 12 CFR 238.94 - Interlocking relationships permitted by statute.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...false Interlocking relationships permitted by statute...94 Interlocking relationships permitted by statute...93 do not apply in the case of any...to service by a single management official...holding company, by a single management official...the stock issued in connection...

  11. 12 CFR 563f.4 - Interlocking relationships permitted by statute.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...true Interlocking relationships permitted by statute...4 Interlocking relationships permitted by statute...3 do not apply in the case of any...to service by a single management official...holding company, by a single management official...the stock issued in connection...

  12. 12 CFR 563f.4 - Interlocking relationships permitted by statute.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...true Interlocking relationships permitted by statute...4 Interlocking relationships permitted by statute...3 do not apply in the case of any...to service by a single management official...holding company, by a single management official...the stock issued in connection...

  13. Automated Verification of Signalling Principles in Railway Interlockings1

    E-print Network

    Setzer, Anton

    AVoCS 2008 Automated Verification of Signalling Principles in Railway Interlockings1 Karim Kanso2 In this paper we present a verification strategy for signalling principles for the control of a railway on a real-world example of a railway interlocking system. The steps in this translation are as follows: 1

  14. 14. General oblique view of Shell Interlocking Tower, north and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. General oblique view of Shell Interlocking Tower, north and west facades, showing over head catenary tower and bridge at right. - New York, New Haven, & Hartford Railroad, Shell Interlocking Tower, New Haven Milepost 16, approximately 100 feel east of New Rochelle Junction, New Rochelle, Westchester County, NY

  15. The Ignition Interlock Program for Drunk Drivers: A Multivariate Test

    Microsoft Academic Search

    Michael Weinrath

    1997-01-01

    The ignition interlock has been touted as a “high-tech” intervention to reduce drunk-driving recidivism. However, it has been difficult to evaluate because outcomes may be a result of program selection. In the study reported here, a random sample of interlock cases was contrasted against a comparison group of impaired drivers in a retrospective analysis. Program effects were tested through a

  16. 6. Detail of northeast corner of Shell Interlocking Tower, showing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. Detail of northeast corner of Shell Interlocking Tower, showing ornamental east concrete beltcourse and tower shield with bronze numerals. - New York, New Haven, & Hartford Railroad, Shell Interlocking Tower, New Haven Milepost 16, approximately 100 feel east of New Rochelle Junction, New Rochelle, Westchester County, NY

  17. Interlocking rogowski coils: A fool`s transformer

    SciTech Connect

    Bartlett, D.F.; Thiesen, J.H. [Univ. of Colorado, Boulder, CO (United States)

    1994-12-31

    We have constructed interlocking, air-core, toroidally-wound solenoids. In principle, there should be no coupling between these Rogowski coils (in the absence of return loop and capacitive effects). We have searched for a mutual inductance between two such interlocking coils and report pre-liminar results.

  18. 4. North elevation of Shell Interlocking Tower showing structure built ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. North elevation of Shell Interlocking Tower showing structure built into slope of railroad right-of-way. - New York, New Haven, & Hartford Railroad, Shell Interlocking Tower, New Haven Milepost 16, approximately 100 feel east of New Rochelle Junction, New Rochelle, Westchester County, NY

  19. 5. General oblique view of Shell Interlocking Tower to southwest, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. General oblique view of Shell Interlocking Tower to southwest, showing east and north facades. Relay station is on far left. - New York, New Haven, & Hartford Railroad, Shell Interlocking Tower, New Haven Milepost 16, approximately 100 feel east of New Rochelle Junction, New Rochelle, Westchester County, NY

  20. 11. General view of Shell Interlocking Tower, west and south ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. General view of Shell Interlocking Tower, west and south facades, view from railroad grade, looking northeast. - New York, New Haven, & Hartford Railroad, Shell Interlocking Tower, New Haven Milepost 16, approximately 100 feel east of New Rochelle Junction, New Rochelle, Westchester County, NY

  1. 21. Historic view looking northeast from tracks of Shell Interlocking ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    21. Historic view looking northeast from tracks of Shell Interlocking Tower after construction, 1909. Photographic copy of photograph published in Railway Age Gazette, February 4, 1910. - New York, New Haven, & Hartford Railroad, Shell Interlocking Tower, New Haven Milepost 16, approximately 100 feel east of New Rochelle Junction, New Rochelle, Westchester County, NY

  2. Distal nephron neoplasms.

    PubMed

    Fleming, Stewart

    2015-03-01

    Tumours of the distal nephron are uncommon but can create diagnostic difficulties. They may be divided into three groups-tumours of intercalated cell phenotype, those of principal cell phenotype and others with an unconfirmed distal nephron origin. Oncocytomas, chromophobe carcinoma and hybrid oncocytoma chromophobe carcinoma, all show features of intercalated cells and the distinction amongst these is one of the most common areas of diagnostic dilemma. Collecting duct carcinoma and renal medullary carcinoma are the most aggressive forms of renal cancer but recent evidence suggests they may respond to targeted therapy so their recognition becomes crucial to the management of these patients. There remains debate over the precise phenotype of both tubulocystic carcinoma and mucinous tubular and spindle cell carcinoma. PMID:25804446

  3. Biodegradable interlocking nails for fracture fixation.

    PubMed

    van der Elst, M; Bramer, J A; Klein, C P; de Lange, E S; Patka, P; Haarman, H J

    1998-12-01

    Serious problems such as stress shielding, allergic reactions, and corrosion are associated with the use of metallic fracture fixation devices in fractured long bones. Metal implants often are removed during a second retrieval operation after fracture healing has completed. A biocompatible implant that degrades slowly during implantation would obviate the need for a second operation and save the patient from considerable physical, psychologic, and financial discomfort. The biodegradable implant must provide the fractured limb sufficient support for a certain time, allowing early loading. A gradual transfer of load from the biodegradable implant to the bone would result in a better product of bone healing and avoid stress shielding. In an animal model using adult sheep, two types of biodegradable polymer interlocking nails were tested in comparison with a stainless steel interlocking nail. Fracture healing, mechanical properties of the bones, degradation behavior in vivo and in vitro, and tissue response were monitored during a 2 1/2-year followup study. To detect shifts in acid base relations caused by the release of acid compounds, pH measurements were performed. Fracture healing was unimpaired, and the mechanical test results of all three groups were excellent. Histologic analysis showed a mild inflammatory response, but no pH shifts were observed. The results of this study justify additional research on these promising materials. PMID:9917717

  4. [The pendulis appliance: a palatal miniscrew supported molar distalization device].

    PubMed

    Nappée-Miévilly, Magali; Nappée, François-Joseph; Kerbrat, Jean-Baptiste; Goudot, Patrick

    2014-09-01

    The maxillary molar distalization is a valuable therapeutic option in some clinical cases. Its biomechanics is challenging and difficult to obtain. Historically, various devices have been described offering successful solutions to this problem such as the Hilgers Pendulum Appliance (1992) and variants linked to mini screws which recently have shown interesting clinical potential. This article presents a new Pendulum variant using a miniscrew, the "pendulis". It follows the original concept (titanium-molybdenum alloy distalization springs and polymethyl-methacrylate pellet) but dental support is replaced by a single palatal miniscrew (median adults, para-median in children) to which the device is fixed by means of a metal welded cap easily positioned and removable by the practitioner. This allows for better control of the oral hygiene and completely controlled extraoral activation. Fabrication steps are described and instruction of use is illustrated with clinical documentation. PMID:25158749

  5. Distal radioulnar joint injuries

    PubMed Central

    Thomas, Binu P; Sreekanth, Raveendran

    2012-01-01

    Distal radioulnar joint is a trochoid joint relatively new in evolution. Along with proximal radioulnar joint, forearm bones and interosseous membrane, it allows pronosupination and load transmission across the wrist. Injuries around distal radioulnar joint are not uncommon, and are usually associated with distal radius fractures,fractures of the ulnar styloid and with the eponymous Galeazzi or Essex_Lopresti fractures. The injury can be purely involving the soft tissue especially the triangular fibrocartilage or the radioulnar ligaments. The patients usually present with ulnar sided wrist pain, features of instability, or restriction of rotation. Difficulty in carrying loads in the hand is a major constraint for these patients. Thorough clinical examination to localize point of tenderness and appropriate provocative tests help in diagnosis. Radiology and MRI are extremely useful, while arthroscopy is the gold standard for evaluation. The treatment protocols are continuously evolving and range from conservative, arthroscopic to open surgical methods. Isolated dislocation are uncommon. Basal fractures of the ulnar styloid tend to make the joint unstable and may require operative intervention. Chronic instability requires reconstruction of the stabilizing ligaments to avoid onset of arthritis. Prosthetic replacement in arthritis is gaining acceptance in the management of arthritis. PMID:23162140

  6. Synthesis of interlocked molecules by olefin metathesis

    NASA Astrophysics Data System (ADS)

    Clark, Paul Gregory

    A large body of work in the Grubbs group has focused on the development of functional-group tolerant ruthenium alkylidene catalysts that perform a number of olefin metathesis reactions. These catalysts have seen application in a wide range of fields, including classic total synthesis as well as polymer and materials chemistry. One particular family of compounds, interlocked molecules, has benefitted greatly from these advances in catalyst stability and activity. This thesis describes several elusive and challenging interlocked architectures whose syntheses have been realized through the utilization of different types of ruthenium-catalyzed olefin metathesis reactions. Ring-closing olefin metathesis has enabled the synthesis of a [c2]daisy-chain dimer with the ammonium binding site near the cap of the dimer. A deprotonated DCD possessing such a structural attribute will more forcefully seek to restore coordinating interactions upon reprotonation, enhancing its utility as a synthetic molecular actuator. Dimer functionalization facilitated incorporation into linear polymers, with a 48% size increase of an unbound, extended analogue of the polymer demonstrating slippage of the dimer units. Ongoing work is directed at further materials studies, in particular, exploring the synthesis of macroscopic networks containing the DCD units and analyzing the correlation between molecular-scale extension-contraction manipulations and resulting macro-scale changes. A "clipping" approach to a polycatenated cyclic polymer, a structure that resembles a molecular "charm bracelet", has been described. The use of ring-opening metathesis polymerization of a carbamate monomer in the presence of a chain transfer agent allowed for the synthesis of a linear polymer that was subsequently functionalized and cyclized to the corresponding cyclic analogue. This cyclic polymer was characterized through a variety of techniques, and subjected to further functionalization reactions, affording a cyclic polyammonium scaffold. Diolefin polyether fragments were coordinated and "clipped" around the ammonium sites within the polymer backbone using ring-closing olefin metathesis, giving the molecular "charm bracelet". Confirmation of the interlocked nature of the product was achieved via 1H NMR spectroscopy and two-dimensional diffusion ordered NMR spectroscopy. A simple strategy for a one-pot, multi-component synthesis of polyrotaxanes using acyclic diene metathesis polymerization was developed. The polyrotaxanes were characterized by traditional 1H NMR spectroscopy as well as size exclusion chromatography, and the interlocked topology was confirmed using two-dimension diffusion-ordered NMR spectroscopy. The dynamic, self-correcting nature of the ADMET polymerization was also explored through the equilibration of a capped polyammonium polymer in the presence of dibenzo-24-crown-8 ether and olefin metathesis catalysts. The efficiency and ease with which these mechanically interlocked macromolecules can be assembled should facilitate rapid modulation to achieve versatile polyrotaxane architectures. Flexible, switchable [c2]daisy-chain dimers (DCDs) were synthesized, where the macromer ammonium binding site was adjacent to the crown-type recognition structure and separated from the cap by an alkyl chain. A DCD of this topology is expected to have an extended structure in the bound conformation (when the ammonium was coordinated to the crown). Several different macromer candidates were designed to allow access to DCDs with flexible alkyl chains between the ammonium binding site and the cap, and a number of synthetic routes were explored in an effort to access these challenging materials. While the first generation DCD structure proved to be unstable due to a labile ester linkage, work is continuing toward the development of several cap structures in an effort to replace the ester linkage with an ether linkage, which, in the second generation model systems, has proven much more stable to the acidic and basic conditions necessary

  7. Helical screw expander evaluation project

    NASA Technical Reports Server (NTRS)

    Mckay, R.

    1982-01-01

    A one MW helical rotary screw expander power system for electric power generation from geothermal brine was evaluated. The technology explored in the testing is simple, potentially very efficient, and ideally suited to wellhead installations in moderate to high enthalpy, liquid dominated field. A functional one MW geothermal electric power plant that featured a helical screw expander was produced and then tested with a demonstrated average performance of approximately 45% machine efficiency over a wide range of test conditions in noncondensing, operation on two-phase geothermal fluids. The Project also produced a computer equipped data system, an instrumentation and control van, and a 1000 kW variable load bank, all integrated into a test array designed for operation at a variety of remote test sites. Data are presented for the Utah testing and for the noncondensing phases of the testing in Mexico. Test time logged was 437 hours during the Utah tests and 1101 hours during the Mexico tests.

  8. Lateral mass screw fixation in children

    PubMed Central

    Proctor, Mark; Hresko, Timothy

    2010-01-01

    Purpose The safety and feasibility of posterior screw fixation of the cervical spine in children has not been well documented in the orthopedic literature. We performed a retrospective review of our experience using posterior cervical screw fixation in children. Methods The medical records and radiologic records of 36 children at a mean age of 10 years (range 3–16 years) were reviewed. Diagnoses included: ten instability, 11 deformity, seven trauma, five tumor, and three congenital abnormalities. Operative reports and postoperative computed tomography (CT) scans were reviewed to determine the technical feasibility of screw placement, any screw-related complications, and to assess for correct screw position. In this series, there were no neurologic complications, no vertebral artery injuries, and no screw-related complications. Results Thirty patients (141 screws) had screws evaluated postoperatively and were shown to be completely contained on postoperative CT scans. There were no revisions due to screw failure or dislodgement. There were no vascular or neurologic complications. Conclusions Posterior screw fixation in the pediatric population may be done safely and greatly enhances fixation strength for a variety of disorders requiring instrumentation and fusion. PMID:21629379

  9. A Comparison of Functional Outcomes After Metallic and Bioabsorbable Interference Screw Fixations in Arthroscopic ACL Reconstructions

    PubMed Central

    Rai, Deepak K; Kannampilly, Antony J

    2014-01-01

    Introduction: Anterior Cruciate Ligament (ACL) is as one of the most frequently injured ligaments in the modern contact sports scenario. Graft fixations can be achieved during anterior cruciate ligament (ACL) reconstructions by using either bioabsorbable screws or metal screws. The objective of this study was to compare the functional outcomes after bioabsorbable and metallic interference screw fixations in arthroscopic anterior cruciate ligament reconstructions done by using hamstring grafts. Materials and Methods: This was a prospective, randomized study. Patients in Group 1 received bioabsorbable interference screws and patients in Group 2 received metallic interference screws. Arthroscopic assisted, anterior cruciate ligament reconstructions with the use of hamstring grafts which were fixed proximally with endobuttons and distally with bioabsorbable or metallic interference screws, were undertaken. Progress in functional outcomes was assessed by using Mann Whitney U- test. Functional outcomes in the two groups were compared by using independent t-test. Observation and Results: In each group, there were statistically significant improvements in functional outcomes over successive follow-ups, which were seen on basis on Mann-Whitney U-test. The comparison of functional outcomes between the two groups, done by using independent t-test, showed no statistically significant differences between the two groups at 3 months, 6 months and 1 year of follow-up. p-value <0.05 was considered to be significant in our study. Conclusion: In our prospective study of comparison of functional outcomes between bioabsorbable and metallic interference screws in arthroscopic anterior cruciate ligament reconstuctions, which were evaluated by using Tegner activity scale and Lysholm knee scoring scale for a period of 1 year, no statistically significant difference was found. However, further authentication is required by doing long term studies. PMID:24959468

  10. Screw fixation diameter for fifth metatarsal jones fracture: a cadaveric study.

    PubMed

    Scott, Ryan T; Hyer, Christopher F; DeMill, Shyler L

    2015-01-01

    The fifth metatarsal Jones fracture is a well-documented injury occurring at the proximal diaphyseal-metaphyseal junction. Conservative versus surgical intervention has been discussed in published studies for the management of Jones fractures. Solid intramedullary fixation relies on accurate matching of the screw diameter to the intraosseous diameter. The purpose of the present cadaveric study was to determine the average intraosseous diameter of the proximal fifth metatarsal as it relates to screw size selection for Jones fracture stabilization. Twenty fresh-frozen cadaver legs were used for examination. The fifth metatarsal was completely dissected. A transverse osteotomy was performed from laterally to medially along the midline of the metatarsal. A digital caliper was used to measure the diameter of the medullary canal of the fifth metatarsal. The measurement was taken at the narrowest portion of the medullary canal just distal to the proximal metaphysis. The mean dorsal to plantar diameter of the fifth metatarsal was 6.475 ± 1.54 (range 4 to 12) mm and the mean medial to lateral diameter was 4.6 ± 0.85 (range 3 to 6) mm. Intramedullary screw fixation has shown beneficial results in the treatment protocol of fifth metatarsal Jones fractures. Our study has demonstrated that a 4.5-mm cannulated screw is the narrowest diameter screw that can be used in the average fifth metatarsal and still obtain adequate intraosseous purchase. When selecting the appropriate screw, the surgeon must be comfortable selecting the largest screw that will achieve the maximal interface with the dense cortical bone in both the medial to lateral and dorsal to plantar plane. PMID:25624041

  11. Distal Radius Fracture (Broken Wrist)

    MedlinePLUS

    ... reduction). Depending on the fracture, there are a number of options for holding the bone in the correct position while it heals: • Cast • Metal pins (usually stainless steel or titanium) • Plate and screws • External ? xator ( ...

  12. Distal radius fixation through a mini-invasive approach of 15 mm. PART 1: a series of 144 cases.

    PubMed

    Lebailly, Frédéric; Zemirline, Ahmed; Facca, Sybille; Gouzou, Stéphanie; Liverneaux, Philippe

    2014-08-01

    The volar Henry approach is becoming the gold standard for distal radius fracture fixation. It decreases the incidence of nonunion, limits complications especially complex regional pain syndrome (CRPS) type I, and allows early mobilization of the wrist. Nonetheless, it has some disadvantages such as the size of the incision, which is not esthetically pleasing, and the loss of ligamentotaxis. This is why some authors have developed a mini-invasive approach. The aim of this work was to evaluate the feasibility of the anterior mini-invasive approach of 15 mm in a clinical series of 144 cases of distal radius fracture. All patients were operated under regional anesthesia using the same techniques by five surgeons of the same team. According to the AO classification, there were 83 type A fractures, 2 type B, and 59 type C. A volar plate (Step One(®), Newclip Technics™, Haute-Goulaine, France) was used in all cases. The 2 proximal metaphyseal screws and the 2 distal central epiphyseal screws were monoaxial locking. The 2 distal ulnar and radial epiphyseal screws were placed in polyaxial locking at 20° angulation maximum. Skin closure without drainage was performed. No postoperative immobilization was prescribed, and patients were encouraged to use their upper limb immediately postoperative. No postoperative physiotherapy was prescribed. The mean follow-up was 4.1 months. The final size of the incision was on average 16.1 mm. Mean pain score was 1.8. The Quick DASH score was average 25. Average range of motion was more than 85 %, and global force of the hand was 67 % compared with contralateral side. On X-ray, the mean radial slope was 22°, the mean radial tilt was 8.3°, and the mean radioulnar variance/index was -0.4 mm. There were nine cases of CRPS type I, which all resolved. Specific complications included two secondary displacements and nine tenosynovitis cases. No tendon rupture was noted. Two intra-articular distal radioulnar joint screws had to be removed at 3 months. One epiphyseal screw required removal 1 month postoperative due to loosening. There were no intra-articular radiocarpal screws. Distal radius fracture fixation using a mini-invasive approach is a reliable and reproducible procedure with few complications. It allows anatomical reduction in the distal radius fractures including intra-articular ones. It can be associated with arthroscopy, scaphoid screw fixation or even percutaneous pinning. Thus, most traumatic lesions of the wrist bony or soft tissue can be treated through this mini-invasive approach. PMID:24258689

  13. Periodic variation of preloading in ball screws

    Microsoft Academic Search

    S. Frey; M. Walther; A. Verl

    2010-01-01

    The preloading is a main characteristic for the functionality of a ball screw. The path of preloading during operation with\\u000a no thrust load is an indicator for the actual inner forces, the friction produced by the ball screw and finally for the quality\\u000a of the unit. Due to manufacturing tolerances the preloading over the useful travel of the ball screw

  14. Power connect safety and connection interlock

    NASA Technical Reports Server (NTRS)

    Rippel, Wally E. (Inventor)

    1992-01-01

    A power connect safety and connection interlock system is shown for use with inverters and other DC loads (16) which include capacitor filter banks (14) at their DC inputs. A safety circuit (20) operates a spring (26) biased, solenoid (22) driven mechanical connection interference (24) which prevents mating and therefore electrical connection between the power contactor halves (11, 13) of the main power contacts (12) until the capacitor bank is safely precharged through auxiliary contacts (18). When the DC load (16) is shut down, the capacitor bank (14) is automatically discharged through a discharging power resistor (66) by a MOSFET transistor (60) through a discharging power resistor (66) only when both the main power contacts and auxiliary contacts are disconnected.

  15. Shock-Absorbent Ball-Screw Mechanism

    NASA Technical Reports Server (NTRS)

    Hirr, Otto A., Jr.; Meneely, R. W.

    1986-01-01

    Actuator containing two ball screws in series employs Belleville springs to reduce impact loads, thereby increasing life expectancy. New application of springs increases reliability of equipment in which ball screws commonly used. Set of three springs within lower screw of ball-screw mechanism absorbs impacts that result when parts reach their upper and lower limits of movement. Mechanism designed with Belleville springs as shock-absorbing elements because springs have good energy-to-volume ratio and easily stacked to attain any stiffness and travel.

  16. LCP distal ulna hook plate as alternative fixation for fifth metatarsal base fracture.

    PubMed

    Lee, Sang Ki; Park, Ju Sang; Choy, Won Sik

    2013-08-01

    Intramedullary screw fixation is the most common treatment for fifth metatarsal base fractures. Screw application does not achieve accurate reduction in fracture with small fragments, osteoporotic bone, or Lawrence zone 1 fractures, however. On the basis of similar anatomical architectures between the distal ulna and the fifth metatarsal base, the purpose of this study was to assess the results of a locking compression plate (LCP) distal ulna hook plate in stabilizing displaced zone 1 or 2 fifth metatarsal base fractures. Nineteen patients with Lawrence zone 1 (n = 12) or 2 (n = 7) fractures of the fifth metatarsal base were treated surgically with an LCP distal ulna hook plate. The patients were evaluated clinically and radiographically, and functional outcomes were graded by using the American Orthopaedic Foot and Ankle Society (AOFAS) midfoot scoring system. Radiographic bony union was obtained in all patients, at an average of 7.4 weeks. The mean AOFAS midfoot score improved from 26 (range, 0-45) preoperatively to 94 (range, 72-100) points at the final follow-up. There were three patients with post-traumatic cubometatarsal arthrosis and one patient with sural nerve neuropraxia. In our experience, the distal ulna hook plate achieves a high rate of bony consolidation and anatomically suitable fixation in zone 1 or 2 fifth metatarsal base fractures. We also suggest that the LCP distal ulna hook plate should be considered as an alternative treatment in multifragmentary, osteoporotic, and tuberosity avulsion (zone 1) fifth metatarsal base fractures. PMID:23412193

  17. Design optimisation and experimental evaluation of dorsal double plating fixation for distal radius fracture.

    PubMed

    Chen, Alvin Chao-Yu; Lin, Yu-Hao; Kuo, Hsien-Nan; Yu, Tsung-Chih; Sun, Ming-Tsung; Lin, Chun-Li

    2013-04-01

    This study determines the relative effects of changes in osteoporosis condition, plate/screw design factors (plate angle/length/width/thickness and screw diameter) and fixation methods (screw number and screw length) on the biomechanical response of dorsal double plating (DDP) fixation at a distal radius fracture to determine the optimal design and evaluate its biomechanical strength using the dynamic fatigue test. Eighteen CAD and finite element (FE) models corresponding to a Taguchi L18 array were constructed to perform numerical simulations to simulate the mechanical responses of a DDP fixed in a simply distal radius fracture bone. The Taguchi method was employed to determine the significance of each design factor in controlling bone/plate/screw stress and distal fragment displacement under axial (100 N), bending (1 N m) and torsion (1 N m) loads. Simulation results indicated that the order rank to determine the mechanical response was the plate thickness, plate width, screw diameter, and number of screws. Dorsal intermediate (L) plate with 60 mm length, 1.8 mm thickness, 6.0 mm width and 2.8 mm diameter, 20 mm length dual-thread locking screw can be found for optimisation. The DDP, including an L plate with 0°, 30° and 60° angles and a straight I plate, were made with Ti6Al4V to fix onto the sawbones with three corresponding radius fractures to perform the dynamic testing. The specimens were oscillated with loads between 10 N and 150 N at 5 Hz for 20,000 cycles. The average stiffness in 20,000 test cycles was 425.7 N/mm, 461.1 N/mm and 532.1N/mm for the 0°, 30° and 60° constructs, respectively. No difference in stiffness was found in the same angled constructs throughout the 20,000 cycles of testing (p > 0.05). Lack of gross construct failures during cyclic testing and reasonable stiffness corroborated that our new constructs tested to date seem stable enough to support restricted post-operative loads. PMID:23099020

  18. DETAIL OF STANDARD INTERLOCKING MACHINE OPERATING LEVERS. LOCKING MECHANISM IS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL OF STANDARD INTERLOCKING MACHINE OPERATING LEVERS. LOCKING MECHANISM IS BELOW FLOOR. BOXES BEHIND SOME LEVERS HOUSE ELECTRICAL CONTACTS FOR SIGNALS. - Baltimore & Ohio Railroad, Z Tower, State Route 46, Keyser, Mineral County, WV

  19. Refining the maintenance techniques for Interlocking Concrete Paver GIs - abstract

    EPA Science Inventory

    Surface clogging adversely affects the performance of Interlocking Concrete Pavements (ICP) by reducing their ability to infiltrate stormwater runoff. Determining the correct methods for remedial maintenances is crucial to recovering and maintaining efficient ICP performance. T...

  20. 23. Looking N up corridor from Chick Interlocking Tower. Boston, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    23. Looking N up corridor from Chick Interlocking Tower. Boston, Suffolk Co., MA. Sec. 4116, MP 227.09. - Northeast Railroad Corridor, Amtrak Route between RI/MA State Line & South Station, Boston, Suffolk County, MA

  1. 93. Old Saybrook Mechanical Interlocking Tower. Old Saybrook, Middlesex Co., ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    93. Old Saybrook Mechanical Interlocking Tower. Old Saybrook, Middlesex Co., CT. Sec. 4209, MP 105.00. - Northeast Railroad Corridor, Amtrak Route between New York/Connecticut & Connecticut/Rhode Island State Lines, New Haven, New Haven County, CT

  2. 12. DETAIL VIEW OF INTERLOCKING RAIL CONNECTION AT FREE END ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. DETAIL VIEW OF INTERLOCKING RAIL CONNECTION AT FREE END OF MOVING LEAF - Seddon Island Scherzer Rolling Lift Bridge, Spanning Garrison Channel from Tampa to Sedden Island, Tampa, Hillsborough County, FL

  3. 95. Old Saybrook Mechanical Interlocking Tower. Old Saybrook, Middlesex Co., ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    95. Old Saybrook Mechanical Interlocking Tower. Old Saybrook, Middlesex Co., CT. Sec. 4209, MP 105.00. - Northeast Railroad Corridor, Amtrak Route between New York/Connecticut & Connecticut/Rhode Island State Lines, New Haven, New Haven County, CT

  4. 9. VIEW, LOOKING NORTHWEST, SHOWING PIPING FOR INTERLOCKING AND SIGNALLING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. VIEW, LOOKING NORTHWEST, SHOWING PIPING FOR INTERLOCKING AND SIGNALLING SYSTEM - New York, New Haven & Hartford Railroad, Niantic Bridge, Spanning Niantic River between East Lyme & Waterford, Old Lyme, New London County, CT

  5. 121. Groton Interlocking Tower. Groton, New London Co., CT. Sec. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    121. Groton Interlocking Tower. Groton, New London Co., CT. Sec. 4215, MP 124.50. - Northeast Railroad Corridor, Amtrak Route between New York/Connecticut & Connecticut/Rhode Island State Lines, New Haven, New Haven County, CT

  6. 92. Old Saybrook Mechanical Interlocking Tower. Old Saybrook, Middlesex Co., ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    92. Old Saybrook Mechanical Interlocking Tower. Old Saybrook, Middlesex Co., CT. Sec. 4209, MP 105.00. - Northeast Railroad Corridor, Amtrak Route between New York/Connecticut & Connecticut/Rhode Island State Lines, New Haven, New Haven County, CT

  7. Any Monotone Function Is Realized by Interlocked Polygons

    E-print Network

    Demaine, Erik D.

    Suppose there is a collection of n simple polygons in the plane, none of which overlap each other. The polygons are interlocked if no subset can be separated arbitrarily far from the rest. It is natural to ask the ...

  8. 38. Saga Interlocking Tower. Greens Farms, Fairfield Co., CT. Sec. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    38. Saga Interlocking Tower. Greens Farms, Fairfield Co., CT. Sec. 9108, MP 47.00. - Northeast Railroad Corridor, Amtrak Route between New York/Connecticut & Connecticut/Rhode Island State Lines, New Haven, New Haven County, CT

  9. 91. Old Saybrook Mechanical Interlocking Tower. Old Saybrook, Middlesex Co., ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    91. Old Saybrook Mechanical Interlocking Tower. Old Saybrook, Middlesex Co., CT. Sec. 4209, MP 105.00. - Northeast Railroad Corridor, Amtrak Route between New York/Connecticut & Connecticut/Rhode Island State Lines, New Haven, New Haven County, CT

  10. INTERIOR VIEW OF WEST BANK RAILROAD CONTROL TOWER SHOWING INTERLOCKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR VIEW OF WEST BANK RAILROAD CONTROL TOWER SHOWING INTERLOCKING SWITCHING LEVER CONTROL PANEL. - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  11. 13. INTERIOR, OPERATOR'S HOUSE, ELECTROMECHANICAL INTERLOCKING MACHINE New York, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. INTERIOR, OPERATOR'S HOUSE, ELECTRO-MECHANICAL INTERLOCKING MACHINE - New York, New Haven & Hartford Railroad, Mystic River Bridge, Spanning Mystic River between Groton & Stonington, Groton, New London County, CT

  12. 42. UPRR interlocking machine in control house (built 1915). Refer ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    42. UPRR interlocking machine in control house (built 1915). Refer to photograph 29. Facing west. - Henry Ford Bridge, Spanning Cerritos Channel, Los Angeles-Long Beach Harbor, Los Angeles, Los Angeles County, CA

  13. 37. Saga Interlocking Tower. Greens Farms, Fairfield Co., CT. Sec. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    37. Saga Interlocking Tower. Greens Farms, Fairfield Co., CT. Sec. 9108, MP 47.00. - Northeast Railroad Corridor, Amtrak Route between New York/Connecticut & Connecticut/Rhode Island State Lines, New Haven, New Haven County, CT

  14. 5. 'A' INTERLOCKING TOWER AND TURNTABLE BEHIND UNION STATION. WASHINGTON, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. 'A' INTERLOCKING TOWER AND TURNTABLE BEHIND UNION STATION. WASHINGTON, D. C. Sec. 1201, MP 137.50. - Northeast Railroad Corridor, Amtrak Route between Union Station & DC/MD State Line, Washington, District of Columbia, DC

  15. 94. Old Saybrook Mechanical Interlocking Tower. Old Saybrook, Middlesex Co., ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    94. Old Saybrook Mechanical Interlocking Tower. Old Saybrook, Middlesex Co., CT. Sec. 4209, MP 105.00. - Northeast Railroad Corridor, Amtrak Route between New York/Connecticut & Connecticut/Rhode Island State Lines, New Haven, New Haven County, CT

  16. Refining the maintenance techniques for Interlocking Concrete Paver GIs

    EPA Science Inventory

    Surface clogging adversely affects the performance of Interlocking Concrete Pavements (ICP) by reducing their ability to infiltrate stormwater runoff. The clogging rate is a function of pavement type, traffic loading, surrounding physical environment and maintenance treatments. ...

  17. Accounting scandals and stigma by association via director interlocks

    E-print Network

    Kang, Soon Lee Eugene

    2006-10-30

    in an associated firm appear to influence the amount of stigma experienced by the associated firm. This dissertation highlights the possible (1) negative consequences of director interlocks, (2) understatement of the social costs of corporate accounting scandals...

  18. Perryville Interlocking Tower. Perryville, Cecil Co., MD. Sec. 1201, MP ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Perryville Interlocking Tower. Perryville, Cecil Co., MD. Sec. 1201, MP 59.10. - Northeast Railroad Corridor, Amtrak route between District of Columbia/Maryland state line & Maryland/Delaware state line, Baltimore, Independent City, MD

  19. Edgewood Interlocking Tower. Edgewood, Hareford Co., MD. Sec. 1201, MP ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Edgewood Interlocking Tower. Edgewood, Hareford Co., MD. Sec. 1201, MP 75.50. - Northeast Railroad Corridor, Amtrak route between District of Columbia/Maryland state line & Maryland/Delaware state line, Baltimore, Independent City, MD

  20. Union Junction Interlocking Tower. Baltimore, Baltimore City, MD. Sec. 1201, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Union Junction Interlocking Tower. Baltimore, Baltimore City, MD. Sec. 1201, MP 95.49. - Northeast Railroad Corridor, Amtrak route between District of Columbia/Maryland state line & Maryland/Delaware state line, Baltimore, Independent City, MD

  1. BOWIE INTERLOCKING TOWER AND PASSENGER STATION. BOWIE, PRINCE GEORGES CO., ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    BOWIE INTERLOCKING TOWER AND PASSENGER STATION. BOWIE, PRINCE GEORGES CO., MD. Sec. 1201, MP 120.50. - Northeast Railroad Corridor, Amtrak route between District of Columbia/Maryland state line & Maryland/Delaware state line, Baltimore, Independent City, MD

  2. B & P Junction Substation & Interlocking Tower. Baltimore, Baltimore ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    B & P Junction Substation & Interlocking Tower. Baltimore, Baltimore City, MD. Sec. 1201, MP 95.85. - Northeast Railroad Corridor, Amtrak route between District of Columbia/Maryland state line & Maryland/Delaware state line, Baltimore, Independent City, MD

  3. Modeling of 3-D Angle-Interlock Textile Structural Composites

    Microsoft Academic Search

    Thomas J. Whitney; Tsu-Wei Chou

    1989-01-01

    A model is developed to predict the in-plane elastic properties of compos ites reinforced with 3-D angle-interlock textile preforms. Straight yarn segments and microcells are utilized in a lamination analogy to predict the in-plane elastic constants. Numerical results for angle-interlock preforms are compared to preliminary test data available in the literature. The effects of varying geometric parameters, namely crimp in

  4. Effectiveness of ignition interlock devices in reducing drunk driving recidivism

    Microsoft Academic Search

    Jeffrey H. Coben; Gregory L. Larkin

    1999-01-01

    Objective: To determine if ignition interlock devices reduce driving while intoxicated (DWI) recidivism.Search Strategies: Cochrane Collaboration search strategies were used.Selection Criteria: Studies for selection examined the effectiveness of interlock programs in a defined population. Studies were required to have a clear description of the program and outcomes evaluated, to have a comparison group and to provide interpretable data.Data Collection and

  5. Noise Level of Precision Ball Screws

    Microsoft Academic Search

    Toshiharu Kajita; Akihiko Ishikawa

    1996-01-01

    We have derived a formula to evaluate the noise level of NSK precision ball screws based on data accumulated for over 10 years. Our database indicates that the factor which plays an important role in ball screw noise is the product of three parameters: ball diameter, ball pitch circle diameter, and rotational speed. The derived formula enables us to estimate

  6. Ball screw type wave power generator

    Microsoft Academic Search

    K.-I. Ohmata; H. Shimoda

    1979-01-01

    To obtain an even flow of electric power form fluctuating wave energy, the authors devised a ball screw type wave power generator (BSTWPG) which consists of a pressure plate, ball screws and nuts, one-way clutches, flywheels and generators. The equations of motion of the BSTWPG system are shown and the digital simulation using Continuous System Simulation Language is developed on

  7. Hindfoot Valgus following Interlocking Nail Treatment for Tibial Diaphysis Fractures: Can the Fibula Be Neglected?

    PubMed

    Uzun, Metin; Kara, Adnan; Ada?, Müjdat; Karslio?lu, Bülent; Bülbül, Murat; Beksaç, Burak

    2014-01-01

    Purpose. We evaluated whether intramedullary nail fixation for tibial diaphysis fractures with concomitant fibula fractures (except at the distal one-third level) managed conservatively with an associated fibula fracture resulted in ankle deformity and assessed the impact of the ankle deformity on lower extremity function. Methods. Sixty middle one-third tibial shaft fractures with associated fibular fractures, except the distal one-third level, were included in this study. All tibial shaft fractures were anatomically reduced and fixed with interlocking intramedullary nails. Fibular fractures were managed conservatively. Hindfoot alignment was assessed clinically. Tibia and fibular lengths were compared to contralateral measurements using radiographs. Functional results were evaluated using the Knee Injury and Osteoarthritis Outcome Score (KOOS) and the Foot and Ankle Disability Index Score (FADI). Results. Anatomic union, defined as equal length in operative and contralateral tibias, was achieved in 60 fractures (100%). Fibular shortening was identified in 42 fractures (68%). Mean fibular shortening was 1.2?cm (range, 0.5-2?cm). Clinical exams showed increased hindfoot valgus in 42 fractures (68%). The mean KOOS was 88.4, and the mean FADI score was 90. Conclusion. Fibular fractures in the middle or proximal one-third may need to be stabilized at the time of tibial intramedullary nail fixation to prevent development of hindfoot valgus due to fibular shortening. PMID:25544899

  8. Hindfoot Valgus following Interlocking Nail Treatment for Tibial Diaphysis Fractures: Can the Fibula Be Neglected?

    PubMed Central

    Uzun, Metin; Kara, Adnan; Ada?, Müjdat; Karslio?lu, Bülent; Bülbül, Murat; Beksaç, Burak

    2014-01-01

    Purpose. We evaluated whether intramedullary nail fixation for tibial diaphysis fractures with concomitant fibula fractures (except at the distal one-third level) managed conservatively with an associated fibula fracture resulted in ankle deformity and assessed the impact of the ankle deformity on lower extremity function. Methods. Sixty middle one-third tibial shaft fractures with associated fibular fractures, except the distal one-third level, were included in this study. All tibial shaft fractures were anatomically reduced and fixed with interlocking intramedullary nails. Fibular fractures were managed conservatively. Hindfoot alignment was assessed clinically. Tibia and fibular lengths were compared to contralateral measurements using radiographs. Functional results were evaluated using the Knee Injury and Osteoarthritis Outcome Score (KOOS) and the Foot and Ankle Disability Index Score (FADI). Results. Anatomic union, defined as equal length in operative and contralateral tibias, was achieved in 60 fractures (100%). Fibular shortening was identified in 42 fractures (68%). Mean fibular shortening was 1.2?cm (range, 0.5–2?cm). Clinical exams showed increased hindfoot valgus in 42 fractures (68%). The mean KOOS was 88.4, and the mean FADI score was 90. Conclusion. Fibular fractures in the middle or proximal one-third may need to be stabilized at the time of tibial intramedullary nail fixation to prevent development of hindfoot valgus due to fibular shortening. PMID:25544899

  9. Surgical indications for distal tibial epiphyseal fractures in children.

    PubMed

    Cai, Haoqi; Wang, Zhigang; Cai, Haiqing

    2015-03-01

    The goal of this study was to investigate the treatment methods and surgical indications of distal tibial epiphyseal fractures in children. Two hundred eighty-six children with distal tibial epiphyseal fractures were included in the study. Among these patients, 202 were male and 84 were female. Mean age was 11.7 years. A retrospective study on the postoperative long-term complications and related risk factors was performed. Treatment methods were determined according to the distance of fracture displacement. A long-leg cast was applied after closed reduction for patients with primary fracture displacement less than 2 mm. For cases with more than 2 mm of fracture displacement, K-wire or screw fixation was performed. For patients with less than 2 mm of fracture displacement, closed reduction and internal fixation was performed. Open reduction was performed in patients with more than 2 mm of fracture displacement, even after closed reduction. Mean follow-up was 6.4 years. Premature physeal closure occurred in 42 patients, and, among them, varus and valgus ankle deformities occurred in 16 patients. Associated fibular fractures and cast immobilization after closed reduction for Salter-Harris type III and IV fractures were risk factors for premature physeal closure. It is not effective to determine the surgical procedure according to the distance of preoperative fracture displacement for improving the prognosis of distal tibial epiphyseal fractures in children. Conservative treatment should be performed for patients with Salter-Harris type I and II distal tibial epiphyseal fractures, and surgery should be performed in patients with Salter-Harris type III and IV distal tibial epiphyseal fractures to reduce the incidence of premature physeal closure. [Orthopedics. 2015; 38(3):e189-e195.]. PMID:25760505

  10. Scarf osteotomy without screw fixation

    Microsoft Academic Search

    M. Maestro

    2007-01-01

    The scarf osteotomy is now well recognised as reliable and effective to contribute to the correction of the majority of hallux\\u000a valgus. The challenge remains for the correction of severe deformities with metatarsus varus angle >18? and Distal Metatarsal\\u000a Articular Angle (DMAA) >15?. In order to significantly improve in 3D the metatarsal head displacements, our scarf design became more oblique,

  11. Alignment of pedicle screws with pilot holes: can tapping improve screw trajectory in thoracic spines?

    PubMed Central

    Erkan, Serkan; Hsu, Brian; Mehbod, Amir A.; Perl, John; Transfeldt, Ensor E.

    2009-01-01

    Pedicle screws are placed using pilot holes. The trajectory of pilot holes can be verified by pedicle sounding or radiographs. However, a pilot hole alone does not insure that the screw will follow the pilot hole. No studies have characterized the risk of misalignment of a pedicle screw with respect to its pilot hole trajectory. The objective of this study was to measure the misalignment angles between pedicle screws and pilot holes with or without tapping. Six human cadaveric thoracic spines were used. One hundred and forty pilot holes were created with a straight probe. Steel wires were temporarily inserted and their positions were recorded with CT scans. The left pedicles were tapped with 4.5 mm fluted tap and the right pedicles remained untapped. Pedicle screws (5.5 mm) were inserted into the tapped and untapped pedicles followed by CT scans. The trajectories of pilot holes and screws were calculated using three-dimensional vector analysis. A total of 133 pilot holes (95%) were inside pedicles. For the untapped side, 14 out of 68 (20%) screws did not follow the pilot holes and were outside the pedicles. For the tapped side, 2 out of 65 (3%) did not follow and breached the pedicles. The average misalignment angles between the screw and pilot hole trajectory were 7.7° ± 6.5° and 5.6° ± 3.2° for the untapped side and tapped side, respectively (P < 0.05). Most pedicle screws had lateral screw breach (13 out of 16) whereas most pilot holes had medial pedicle breach (6 out of 7). Tapping of pilot holes (1 mm undertap) helps align pedicle screws and reduces the risk of screw malposition. Although most pedicle screws had lateral breach, the risk of medial pedicle breach of the pilot holes must be recognized. PMID:19526377

  12. Screw-released roller brake

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (Inventor)

    1999-01-01

    A screw-released roller brake including an input drive assembly, an output drive assembly, a plurality of locking sprags, a mechanical tripper nut for unlocking the sprags, and a casing therefor. The sprags consist of three dimensional (3-D) sprag members having pairs of contact surface regions which engage respective pairs of contact surface regions included in angular grooves or slots formed in the casing and the output drive assembly. The sprags operate to lock the output drive assembly to the casing to prevent rotation thereof in an idle mode of operation. In a drive mode of operation, the tripper is either self actuated or motor driven and is translated linearly up and down against a spline and at the limit of its travel rotates the sprags which unlock while coupling the input drive assembly to the output drive assembly so as to impart a turning motion thereto in either a clockwise or counterclockwise direction.

  13. The principle of topological interlocking in extraterrestrial construction

    NASA Astrophysics Data System (ADS)

    Dyskin, A. V.; Estrin, Y.; Pasternak, E.; Khor, H. C.; Kanel-Belov, A. J.

    2005-07-01

    Applications of a newly established principle of topological interlocking to different types of extraterrestrial construction are considered. Topological interlocking arises when elements of special shapes (usually convex or nearly convex, such that no stress concentration develops) are arranged in such a way that neither of them can be removed from the assembly without disturbing the neighbouring elements. Two types of extraterrestrial structures are considered. The first type represents mortar free structures built from specially engineered interlocking bricks, called osteomorphic bricks. The self-adjusting property of these bricks permits erecting structures which tolerate low precision of production and assembly, thus making the proposed method suitable for in situ produced bricks and low cost assembling machinery. The structures of the second type are modular extraterrestrial bases or space ships organised in topologically interlocking assemblies. For an extraterrestrial settlement such an organisation permits easy assembly even if the modules are uploaded on uneven ground. A space ship can be assembled from independent smaller ships interlocked topologically thus becoming a flexible vehicle suitable for both long-distance journeys and simultaneous exploration of extraterrestrial objects clustered in a relative proximity of each other.

  14. Adaptive mechanical properties of topologically interlocking material systems

    NASA Astrophysics Data System (ADS)

    Khandelwal, S.; Siegmund, T.; Cipra, R. J.; Bolton, J. S.

    2015-04-01

    Topologically interlocked material systems are two-dimensional granular crystals created as ordered and adhesion-less assemblies of unit elements of the shape of platonic solids. The assembly resists transverse forces due to the interlocking geometric arrangement of the unit elements. Topologically interlocked material systems yet require an external constraint to provide resistance under the action of external load. Past work considered fixed and passive constraints only. The objective of the present study is to consider active and adaptive external constraints with the goal to achieve variable stiffness and energy absorption characteristics of the topologically interlocked material system through an active control of the in-plane constraint conditions. Experiments and corresponding model analysis are used to demonstrate control of system stiffness over a wide range, including negative stiffness, and energy absorption characteristics. The adaptive characteristics of the topologically interlocked material system are shown to solve conflicting requirements of simultaneously providing energy absorption while keeping loads controlled. Potential applications can be envisioned in smart structure enhanced response characteristics as desired in shock absorption, protective packaging and catching mechanisms.

  15. Transpedicular screw fixation in the thoracic and lumbar spine with a novel cannulated polyaxial screw system

    PubMed Central

    Weise, Lutz; Suess, Olaf; Picht, Thomas; Kombos, Theodoros

    2008-01-01

    Objective: Transpedicular screws are commonly and successfully used for posterior fixation in spinal instability, but their insertion remains challenging. Even using navigation techniques, there is a misplacement rate of up to 11%. The aim of this study was to assess the accuracy of a novel pedicle screw system. Methods: Thoracic and lumbar fusions were performed on 67 consecutive patients for tumor, trauma, degenerative disease or infection. A total of 326 pedicular screws were placed using a novel wire-guided, cannulated, polyaxial screw system (XIA Precision®, Stryker). The accuracy of placement was assessed postoperatively by CT scan, and the patients were followed-up clinically for a mean of 16 months. Results: The total medio-caudal pedicle wall perforation rate was 9.2% (30/326). In 19 of these 30 cases a cortical breakthrough of less than 2 mm occurred. The misplacement rate (defined as a perforation of 2 mm or more) was 3.37% (11/326). Three of these 11 screws needed surgical revision due to neurological symptoms or CSF leakage. There have been no screw breakages or dislocations over the follow up-period. Conclusion: We conclude that the use of this cannulated screw system for the placement of pedicle screws in the thoracic and lumbar spine is accurate and safe. The advantages of this technique include easy handling without a time-consuming set up. Considering the incidence of long-term screw breakage, further investigation with a longer follow-up period is necessary. PMID:22915906

  16. Metal artifacts from titanium and steel screws in CT, 1.5T and 3T MR images of the tibial Pilon: a quantitative assessment in 3D

    PubMed Central

    Radzi, Shairah; Cowin, Gary; Robinson, Mark; Pratap, Jit; Volp, Andrew; Schuetz, Michael A.

    2014-01-01

    Radiographs are commonly used to assess articular reduction of the distal tibia (pilon) fractures postoperatively, but may reveal malreductions inaccurately. While magnetic resonance imaging (MRI) and computed tomography (CT) are potential three-dimensional (3D) alternatives they generate metal-related artifacts. This study aims to quantify the artifact size from orthopaedic screws using CT, 1.5T and 3T MRI data. Three screws were inserted into one intact human cadaver ankle specimen proximal to and along the distal articular surface, then CT, 1.5T and 3T MRI scanned. Four types of screws were investigated: titanium alloy (TA), stainless steel (SS) (Ø =3.5 mm), cannulated TA (CTA) and cannulated SS (CSS) (Ø =4.0 mm, Ø empty core =2.6 mm). 3D artifact models were reconstructed using adaptive thresholding. The artifact size was measured by calculating the perpendicular distance from the central screw axis to the boundary of the artifact in four anatomical directions with respect to the distal tibia. The artifact sizes (in the order of TA, SS, CTA and CSS) from CT were 2.0, 2.6, 1.6 and 2.0 mm; from 1.5T MRI they were 3.7, 10.9, 2.9, and 9 mm; and 3T MRI they were 4.4, 15.3, 3.8, and 11.6 mm respectively. Therefore, CT can be used as long as the screws are at a safe distance of about 2 mm from the articular surface. MRI can be used if the screws are at least 3 mm away from the articular surface except for SS and CSS. Artifacts from steel screws were too large thus obstructed the pilon from being visualised in MRI. Significant differences (P<0.05) were found in the size of artifacts between all imaging modalities, screw types and material types, except 1.5T versus 3T MRI for the SS screws (P=0.063). CTA screws near the joint surface can improve postoperative assessment in CT and MRI. MRI presents a favourable non-ionising alternative when using titanium hardware. Since these factors may influence the quality of postoperative assessment, potential improvements in operative techniques should be considered. PMID:24914417

  17. Flow patterns in twin-screw extruders

    Microsoft Academic Search

    O. S. Carneiro; G. Caldeira; J. A. Covas

    1999-01-01

    Flow visualisation studies in an intermeshing co-rotating twin-screw extruder operated under starve-fed conditions are presented. Different numbers of kneading discs and relative staggering angles were used in the definition of the mixing blocks. Conveying and left-handed elements were also utilised. The images recorded provided information on flow patterns, on the degree of filling of the screw channels and on the

  18. The lateral fixation screw in implant dentistry.

    PubMed

    Sethi, A; Sochor, P

    2000-03-01

    This clinical report presents a means of retaining implant supported superstructures using lateral fixation screws (Novadent). 244 lateral fixation screws have been used for the retention of a variety of restorations including single teeth, short span and full arch bridgework as well as overdenture bars. Over a period of observation of 4 years, the authors have found the restorations to have effective retention, ease of retrievability, good aesthetics and occlusal contours. PMID:11307389

  19. Parametric modeling of ball screw spindles

    Microsoft Academic Search

    A. Dadalau; M. Mottahedi; K. Groh; A. Verl

    2010-01-01

    In the product development process numerical optimization can successfully be applied in the early product design stages.\\u000a In the very common case of ball screw drives, the dynamical behavior is most depending on the geometrical shape of the ball\\u000a screw itself. Properties like axial and torsional stiffness, moment of inertia, maximum velocity and acceleration are determined\\u000a not only by the

  20. Design of a dependable Interlock System for linear colliders

    E-print Network

    Nouvel, Patrice

    For high energy accelerators, the interlock system is a key part of the machine protection. The interlock principle is to inhibit the beam either on failure of critical equipment and/or on low beam quality evaluation. The dependability of such a system is the most critical parameter. This thesis presents the design of an dependable interlock system for linear collider with an application to the CLIC (Compact Linear Collider) project. This design process is based on the IEEE 1220 standard and is is divided in four steps. First, the specifications are established, with a focus on the dependability, more precisely the reliability and the availability of the system. The second step is the design proposal based on a functional analysis, the CLIC and interfaced systems architecture. Third, the feasibility study is performed, applying the concepts in an accelerator facility. Finally, the last step is the hardware verification. Its aim is to prove that the proposed design is able to reach the requirements.

  1. PLC-based interlock system for superconducting magnets

    SciTech Connect

    Agostini, R.C.; Barker, L.; Hodgers, J.; Reagan, D.; Walz, H.V. (Stanford Univ., CA (USA))

    1989-10-01

    Conventional interlock systems rely heavily on hard-wired electromagnetic relays. Although this approach is well understood and has proven to be reliable, several drawbacks plague the designer as well as the repairman. If larger systems have to be implemented in relay logic, the complexity limit is soon reached; the systems become too bulky, and wiring expenses sky-rocket; moreover, the intelligence of those designs is limited in such a way that desirable features such as self-tests have to be left out. Additionally, relay interlocks are inherently inflexible: if the configuration of the system they protect has to change, a disproportional amount of time, work and money has to be invested in order to adapt the hard-wiring of the interlock system to the new requirements. Repair work is often unnecessarily delayed due to the lack of adequate documentation.

  2. 1. ENVIRONMENT, FROM NORTHWEST, SHOWING B&P INTERLOCKING TOWER AND POWER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. ENVIRONMENT, FROM NORTHWEST, SHOWING B&P INTERLOCKING TOWER AND POWER SUBSTATIONS - Baltimore & Potomac Interlocking Tower, Adjacent to AMTRAK railroad tracks in block bounded by Howard Street, Jones Falls Expressway, Maryland Avenue & Falls Road, Baltimore, Independent City, MD

  3. 49 CFR 236.340 - Electromechanical interlocking machine; locking between electrical and mechanical levers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...Instructions § 236.340 Electromechanical interlocking machine; locking between electrical and mechanical levers. In electro-mechanical interlocking machine, locking between electric and mechanical levers shall be maintained so that mechanical...

  4. 49 CFR 236.340 - Electromechanical interlocking machine; locking between electrical and mechanical levers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...Instructions § 236.340 Electromechanical interlocking machine; locking between electrical and mechanical levers. In electro-mechanical interlocking machine, locking between electric and mechanical levers shall be maintained so that mechanical...

  5. 12 CFR 250.410 - Interlocking relationships between bank and its commingled investment account.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...410 Interlocking relationships between bank and its...Banking Act of 1933 in view of the interlocking relationships that would exist between...have been developed in respect to the application...would constitute a single entity for the...

  6. 12 CFR 250.410 - Interlocking relationships between bank and its commingled investment account.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...410 Interlocking relationships between bank and its...Banking Act of 1933 in view of the interlocking relationships that would exist between...have been developed in respect to the application...would constitute a single entity for the...

  7. 12 CFR 250.410 - Interlocking relationships between bank and its commingled investment account.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...410 Interlocking relationships between bank and its...Banking Act of 1933 in view of the interlocking relationships that would exist between...have been developed in respect to the application...would constitute a single entity for the...

  8. 18 CFR 45.9 - Automatic authorization of certain interlocking positions.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...INTERLOCKING POSITIONS § 45.9 Automatic authorization of certain interlocking...primary business, owns or operates transmission or generating facilities to provide...condition, and will constitute automatic denial. (c)...

  9. 18 CFR 45.9 - Automatic authorization of certain interlocking positions.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...INTERLOCKING POSITIONS § 45.9 Automatic authorization of certain interlocking...primary business, owns or operates transmission or generating facilities to provide...condition, and will constitute automatic denial. (c)...

  10. 18 CFR 45.9 - Automatic authorization of certain interlocking positions.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...INTERLOCKING POSITIONS § 45.9 Automatic authorization of certain interlocking...primary business, owns or operates transmission or generating facilities to provide...condition, and will constitute automatic denial. (c)...

  11. 18 CFR 45.9 - Automatic authorization of certain interlocking positions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...INTERLOCKING POSITIONS § 45.9 Automatic authorization of certain interlocking...primary business, owns or operates transmission or generating facilities to provide...condition, and will constitute automatic denial. (c)...

  12. 18 CFR 45.9 - Automatic authorization of certain interlocking positions.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...INTERLOCKING POSITIONS § 45.9 Automatic authorization of certain interlocking...primary business, owns or operates transmission or generating facilities to provide...condition, and will constitute automatic denial. (c)...

  13. 49 CFR 236.476 - Interlocking inspections and tests applicable to traffic control systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...Transportation 4 2013-10-01 2013-10-01 false Interlocking inspections and tests applicable to traffic control systems...Traffic Control Systems Inspection and Tests § 236.476 Interlocking inspections and tests applicable to traffic control...

  14. 49 CFR 236.476 - Interlocking inspections and tests applicable to traffic control systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...Transportation 4 2012-10-01 2012-10-01 false Interlocking inspections and tests applicable to traffic control systems...Traffic Control Systems Inspection and Tests § 236.476 Interlocking inspections and tests applicable to traffic control...

  15. 49 CFR 236.426 - Interlocking rules and instructions applicable to traffic control systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...Transportation 4 2012-10-01 2012-10-01 false Interlocking rules and instructions applicable to traffic control systems...Control Systems Rules and Instructions § 236.426 Interlocking rules and instructions applicable to traffic control...

  16. 49 CFR 236.476 - Interlocking inspections and tests applicable to traffic control systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...Transportation 4 2011-10-01 2011-10-01 false Interlocking inspections and tests applicable to traffic control systems...Traffic Control Systems Inspection and Tests § 236.476 Interlocking inspections and tests applicable to traffic control...

  17. 49 CFR 236.476 - Interlocking inspections and tests applicable to traffic control systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...Transportation 4 2010-10-01 2010-10-01 false Interlocking inspections and tests applicable to traffic control systems...Traffic Control Systems Inspection and Tests § 236.476 Interlocking inspections and tests applicable to traffic control...

  18. 49 CFR 236.426 - Interlocking rules and instructions applicable to traffic control systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...Transportation 4 2014-10-01 2014-10-01 false Interlocking rules and instructions applicable to traffic control systems...Control Systems Rules and Instructions § 236.426 Interlocking rules and instructions applicable to traffic control...

  19. 49 CFR 236.426 - Interlocking rules and instructions applicable to traffic control systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...Transportation 4 2011-10-01 2011-10-01 false Interlocking rules and instructions applicable to traffic control systems...Control Systems Rules and Instructions § 236.426 Interlocking rules and instructions applicable to traffic control...

  20. 49 CFR 236.426 - Interlocking rules and instructions applicable to traffic control systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...Transportation 4 2010-10-01 2010-10-01 false Interlocking rules and instructions applicable to traffic control systems...Control Systems Rules and Instructions § 236.426 Interlocking rules and instructions applicable to traffic control...

  1. Safety criteria for the vital processor interlocking at HoornKersenboogerd

    E-print Network

    Fokkink, Wan

    Safety criteria for the vital processor interlocking at Hoorn­Kersenboogerd Wan Fokkink Department­ Kersenboogerd, computer equipment based on a Vital Processor Interlock- ing (VPI) is used in order to ensure

  2. 49 CFR 236.426 - Interlocking rules and instructions applicable to traffic control systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...Transportation 4 2013-10-01 2013-10-01 false Interlocking rules and instructions applicable to traffic control systems...Control Systems Rules and Instructions § 236.426 Interlocking rules and instructions applicable to traffic control...

  3. 49 CFR 236.476 - Interlocking inspections and tests applicable to traffic control systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...Transportation 4 2014-10-01 2014-10-01 false Interlocking inspections and tests applicable to traffic control systems...Traffic Control Systems Inspection and Tests § 236.476 Interlocking inspections and tests applicable to traffic control...

  4. Distal biceps tendon injuries--current treatment options.

    PubMed

    Quach, Tony; Jazayeri, Reza; Sherman, Orrin H; Rosen, Jeffrey E

    2010-01-01

    Three percent of all biceps tendon ruptures occur at the distal aspect, where the tendon inserts into the radial tuberosity. Distal bicep tendon ruptures typically occur in middle-aged males after an eccentric extension load is applied to the elbow. Patients usually complain of a sudden, sharp, and painful tearing sensation in the antecubital region, with a palpable defect. The biceps squeeze and hook tests are specific maneuvers by which to diagnose distal biceps ruptures on physical examination. Magnetic resonance imaging (MRI) or ultrasound maybe be helpful to distinguish between partial and complete tears. Anatomic studies suggest there are two distinct insertions for the short and long heads of the distal biceps. The short head may be a more powerful flexor, and the long head may be a more powerful supinator. Nonoperative treatment typically results in loss of flexion and supination strength and endurance. Early anatomic re-attachment is the goal. Surgical approaches include one- or two-incision techniques, and tendon fixation methods include the use of suture anchors, bone tunnels, an endobutton, or biotenodesis screws. Biomechanical studies have shown that endobuttons have higher load-to-failure strengths, compared to the other fixation methods. However, clinical studies have demonstrated that patients do well regardless of surgical approach or fixation method. Possible complications include nerve injuries, heterotopic ossification, postoperative fracture, tendon rerupture, complex regional pain syndrome, and wound infection. Partial ruptures are significantly less common and initially can be treated conservatively. Chronic tears are more difficult to treat because of possible tendon retraction and poor tissue quality. Tendon grafts using semitendinosus, fascia lata, hamstring, Achilles (calcaneal), or flexor carpi radialis have been successfully used for length restoration in these cases. PMID:20632985

  5. Fiduciary duties of interlocking directors within a nonprofit health system.

    PubMed

    Hershey, Nathan; Jarzab, Christine M

    2005-01-01

    In response to regulatory and financial pressures, entities participating in the healthcare industry have joined with others in order to maintain, even improve, their market positions. In the non-profit sector of the industry, partnerships, mergers, and acquisitions have included arrangements whereby some corporate partners have interlocking directors. After review of the fiduciary duties of care and loyalty owed by corporate board members, and their application to traditional performance and conflict of interest situations, the authors address two scenarios raising interlocking director issues. PMID:16477798

  6. Design review report for the hydrogen interlock preliminary design

    SciTech Connect

    Corbett, J.E.

    1996-01-01

    This report documents the completion of a preliminary design review for the hydrogen interlock. The hydrogen interlock, a proposed addition to the Rotary Mode Core Sampling (RMCS) system portable exhauster, is intended to support core sampling operations in waste tanks requiring flammable gas controls. The objective of this review was to validate basic design assumptions and concepts to support a path forward leading to a final design. The conclusion reached by the review committee was that the design was acceptable and efforts should continue toward a final design review.

  7. Evaluation of a program to motivate impaired driving offenders to install ignition interlocks

    Microsoft Academic Search

    Robert B. Voas; Kenneth O. Blackman; A. Scott Tippetts; Paul R. Marques

    2001-01-01

    Approximately 30,000 alcohol ignition interlocks, which are designed to prevent the operation of a vehicle if the driver has been drinking, are in use in the US and Canada. Ignition interlock programs are also being initiated in Sweden and Australia. The best-controlled studies that are currently available suggest that ignition interlocks are effective in reducing impaired driving recidivism while on

  8. Interlocking Rhythms, Duration Interval Content, Cyclotomic Sets, and the Hexachordal Theorem

    E-print Network

    Toussaint, Godfried T.

    Interlocking Rhythms, Duration Interval Content, Cyclotomic Sets, and the Hexachordal Theorem of interlocking rhythms. Two rhythms which are not congruent but possess the same multiset of distances are said of interlocking rhythms in African and Eu- ropean music. Then we review the history of the hexachordal theorem

  9. Explicit State Model Checking in the Development Process for Interlocking Software Systems

    E-print Network

    Leue, Stefan

    Explicit State Model Checking in the Development Process for Interlocking Software Systems of explicit state model checking technology in the design of railroad interlocking systems. We discuss our of this paper is available under the title Software Quality Assurance for Interlocking Systems using Explicit

  10. Short Interlocked Linkages Erik D. Demaine Stefan Langerman y Joseph O'Rourke z

    E-print Network

    O'Rourke, Joseph

    Short Interlocked Linkages Erik D. Demaine #3; Stefan Langerman y Joseph O'Rourke z Abstract We study collections of O(1) linkages in 3-space, each with O(1) joints, that are interlocked in the sense results are proofs that a trian- gle and an open 4-chain can interlock, as can a quadrilateral and an open

  11. Rigidity-Stability Relationship in Interlocked Model Complexes Containing Phenylene-Ethynylene-Based Disubstituted Naphthalene

    E-print Network

    Goddard III, William A.

    Rigidity-Stability Relationship in Interlocked Model Complexes Containing Phenylene in mechanically interlocked compounds, the binding abilities of two -electron-rich model compounds (2 and 4-acceptor pairs have been employed widely as components of mechanically interlocked molecules (MIMs), rotaxanes

  12. Measurement of the ground-state distributions in bistable mechanically interlocked molecules using

    E-print Network

    Goddard III, William A.

    Measurement of the ground-state distributions in bistable mechanically interlocked molecules using, 2011 (received for review June 20, 2011) In donor­acceptor mechanically interlocked molecules that exists between the two translational isomers in the case of all three mechanically interlocked molecules

  13. Veri cation of Interlockings: from Control Tables to Ladder Logic Diagrams

    E-print Network

    Grant, P. W.

    Veri cation of Interlockings: from Control Tables to Ladder Logic Diagrams Wan Fokkink and Paul in a railway yard are tabulated in control tables. An interlocking, which guarantees validity and derailments have to be avoided. This is done by means of an interlocking, which is a medium between

  14. Interlock Avoidance in Transparent and Dynamic Parallel Program Instrumentation Using Logical Clocks

    E-print Network

    Zhang, Kang

    Interlock Avoidance in Transparent and Dynamic Parallel Program Instrumentation Using Logical processes wait on each other's logical clock to advance, an interlock situation may occur, where none of the processes can continue to execute. This paper presents a strategy to avoid the interlock situations, based

  15. Interlocking control by Distributed Signal Boxes: design and verification with the SPIN model checker

    E-print Network

    Katsaros, Panagiotis

    1 Interlocking control by Distributed Signal Boxes: design and verification with the SPIN model control design is applied to a railway- interlocking problem and more precisely, to the Athens underground metro sys- tem. Signal boxes correspond to the network's interlocking points and commu- nicate only

  16. Comptes Rendus des JNC 17 -Poitiers 2011 Choc mou basse nergie sur composite interlock 3X

    E-print Network

    Paris-Sud XI, Université de

    Comptes Rendus des JNC 17 - Poitiers 2011 Choc mou basse énergie sur composite interlock 3X : approche expérimentale et numérique. Low energy soft impact on interlock3X composite : experimental impacteur déformable en caoutchouc et une plaque composite tissée 3D (interlock 3X). Des impacts basses

  17. Do somatic markers need to be somatic? Analogies from evolution and from hardware interlocks

    E-print Network

    Kent, University of

    Do somatic markers need to be somatic? Analogies from evolution and from hardware interlocks Colin with the concept of hardware interlocks in safety-critical systems. This is used to suggest why it is important of hardware interlocks in engineering design. 2 Could "somatic" markers extend beyond the body? Why do markers

  18. Physics Division ESH Bulletin 99-4 LASER INTERLOCK BYPASSED IN

    E-print Network

    Physics Division ESH Bulletin 99-4 LASER INTERLOCK BYPASSED IN VIOLATION OF OPERATING PROCEDURE On April 22, 1999, at the Brookhaven National Laboratory, safety personnel found that a laser interlock allowed bypassing the intended interlock function. Two visiting researchers (trained and qualified

  19. DESIGN PROCESS OF THE INTERLOCK SYSTEM FOR THE COMPACT LINEAR COLLIDER

    E-print Network

    Paris-Sud XI, Université de

    DESIGN PROCESS OF THE INTERLOCK SYSTEM FOR THE COMPACT LINEAR COLLIDER P. Nouvel1,2,3 , B. Puccio1-31400 Toulouse, France 3 Univ de Toulouse, INP, F-31400 Toulouse, France Abstract The Interlock system the on- going process to validate design choices for the Compact Linear Collider (CLIC) Interlock System

  20. Evaluation of a program to motivate impaired driving offenders to install ignition interlocks

    Microsoft Academic Search

    Robert B. Voas; Kenneth O. Blackman; A. Scott Tippetts; Paul R. Marques

    2002-01-01

    Approximately 30,000 alcohol ignition interlocks, which are designed to prevent the operation of a vehicle if the driver has been drinking, are in use in the US and Canada. Ignition interlock programs are also being initiated in Sweden and Australia. The best-controlled studies that are currently available suggest that ignition interlocks are effective in reducing impaired driving recidivism while on

  1. Dependability Requirements and Design Compliance for Interlock P. Nouvel1,2,3

    E-print Network

    Boyer, Edmond

    Dependability Requirements and Design Compliance for Interlock Systems P. Nouvel1,2,3 , B. Puccio1. This paper presents a new methodology to determine dependability requirements for Interlock systems particles accelerators field, Interlock Sys- tems are key part of the machine protection systems. At CERN

  2. Comptes Rendus des JNC 17 -Poitiers 2011 Comportement spcifique de structures 3D interlock tisses contre

    E-print Network

    Paris-Sud XI, Université de

    Comptes Rendus des JNC 17 - Poitiers 2011 1 Comportement spécifique de structures 3D interlock tissées contre les impacts à haute vitesse Specific behaviour of 3D warp interlock structures against high. Les tissus 3D dont les interlocks chaines sont généralement définis en trois groupes : les couche à

  3. SHORT REPORT Interlocking finger test: a bedside screen for parietal lobe

    E-print Network

    Moo, Lauren R.

    SHORT REPORT Interlocking finger test: a bedside screen for parietal lobe dysfunction L R Moo, S D of an interlocking finger task in screening for parietal lobe dysfunction. The ability of 69 patients to imitate a standardised set of four interlocking finger figures was compared with concurrent performance on formal

  4. The operation result of supervisory interlock system for the KSTAR 1st campaign

    Microsoft Academic Search

    Jaesic Hong; Kap-Rae Park; Yong Chu; Young-Ok Kim; K. P. Kim; Jae-Hoon Choi; Hee-Soo Kim; Jong-Dae Kong; Dong-Seok Lim; Myung-Kyu Kim; Hyun-Sik Chang; Young-Ju Lee; Tae-Gu Lee; Sangil Lee; Chong-Su Kim; Yeong-Kook Oh; Hoonkyun Na; Joo-Shik Bak; M. Kwon; G. S. Lee

    2010-01-01

    The supervisory interlock system (SIS), the personal safety interlock (PSI) and the radiation monitoring system (RMS) are the safety and protection system for the KSTAR operations. The supervisory interlock system prevents men and devices from an accident and it protects auxiliary systems and the superconducting tokamak against the propagation hazardous events. SIS is collecting events of the tokamak and auxiliary

  5. 12 CFR 250.410 - Interlocking relationships between bank and its commingled investment account.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 false Interlocking relationships between bank and its commingled...250.410 Interlocking relationships between bank and its commingled...view of the interlocking relationships that would exist between...would be credited with a number of units proportionate...

  6. 12 CFR 250.410 - Interlocking relationships between bank and its commingled investment account.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 false Interlocking relationships between bank and its commingled...250.410 Interlocking relationships between bank and its commingled...view of the interlocking relationships that would exist between...would be credited with a number of units proportionate...

  7. Complications at screw removal in slipped capital femoral epiphysis treated by cannulated titanium screws

    Microsoft Academic Search

    T. Ilchmann; K. Parsch

    2006-01-01

    Introduction: Various modes of fixation are proposed for the treatment of slips of the capital femoral epiphysis (SCFE). We describe our experience with the use and removal of a new, cannulated titanium screw (Asnis III, Stryker®, Howmedica). Patients and methods: Single cannulated titanium screws had been inserted in 101 hips of 65 patients in the 3-year period from 2001 to

  8. The Turn of the Screw: Optimal Design of an Archimedes Screw

    Microsoft Academic Search

    Chris Rorres

    2000-01-01

    The geometry of an Archimedes screw is governed by certain external parameters (its outer radius, length, and slope) and certain internal parameters (its inner radius, number of blades, and the pitch of the blades). The external parameters are usually determined by the location of the screw and how much water is to be lifted. The internal parameters, however, are free

  9. Modified Trajectory of C2 Laminar Screw - Double Bicortical Purchase of the Inferiorly Crossing Screw

    PubMed Central

    You, Seung-Hoon; Jang, Yeon-Gyu; Lee, Sang-Youl

    2008-01-01

    The crossing laminar screw fixation might be the most recently developed approach among various fixation techniques for C2. The new construct has stability comparable to transarticular or transpedicular screw fixation without risk of vertebral artery injury. Quantitative anatomical studies about C2 vertebra suggest significant variation in the thickness of C2 lamina as well as cross sectional area of junction of lamina and spinous process. We present an elderly patient who underwent an occipito-cervical stabilization incorporating crossed C2 laminar screw fixation. We preoperatively recognized that she had low profiles of C2 lamina, and thus made a modification of trajectory for the inferiorly crossing screw. We introduce a simple modification of crossing C2 laminar screw technique to improve stability in patients with low laminar profiles. PMID:19096618

  10. Temperature calculation for extruder screws with internal heat pipes

    NASA Astrophysics Data System (ADS)

    Lakemeyer, C.; Schöppner, V.

    2014-05-01

    One possibility of directly influencing the temperature profile in an extruder is by tempering the screw. This method is currently used in double-screw extrusion and in certain specialized applications in the field of single-screw extrusion. Significant possibilities of influencing the temperature have been shown, for example, while processing PVC on counterrotating double-screw extruders [1]. However, until now, it has not been possible to theoretically model this effect. This paper will thus introduce a mathematical model which describes the effect of internal screw tempering on the temperature gradient of the material in the extruder, allowing processes using tempered screws to be better designed and dimensioned.

  11. THE INTERLOCK SYSTEM FOR U7 UNDULATOR IN PLS

    Microsoft Academic Search

    G. S. Lee; J. T. Noh; J. Y. Huang; I. S. Ko

    The U7 undulator, the first insertion device in PLS, has been installed at #8 straight section in July 1997. It is expected to produce high intensity photon beam from early1998. Since the high intense photon beam can cause severe thermal damage on vacuum chamber by improperly steered electron beam orbit, the interlock system should be implemented to prevent thermal damage.

  12. TTCN-3 Testing of Hoorn-Kersenboogerd Railway Interlocking

    Microsoft Academic Search

    Jens R. Calame; Nicolae Goga; Natalia Ioustinova; Jaco Van De Pol

    2006-01-01

    Railway control systems are safety-critical, so we have to ensure that they are designed and implemented correctly. Testing these systems is a key issue. Prior to system testing, the software of a railway control system is tested separately from the hardware. The interlocking is a layer of railway control systems that guarantees safety. It allows to execute commands given by

  13. Computerized Interlocking System for Railway Signaling Control: SMILE

    Microsoft Academic Search

    Katsuji Akita; Toshikatsu Watanabe; Hideo Nakamura; Ikumasa Okumura

    1985-01-01

    A computerized interlocking system for railway signaling control is proposed. The overall architecture of this system, aiming at a high degree of safety, reliability, and flexibility, is shown. The basic architecture of both a fail-safe microcomputer subsystem which is the kernel of this system and system-bus structured multimicrocomputer subsystem is discussed. Based on the results of the quantitative evaluation, system

  14. Networks, Interlocking Directors and Strategy: Toward a Theoretical Framework

    Microsoft Academic Search

    Loizos Heracleous; John Murray

    2001-01-01

    Research on inter-organisational networks reflects their acknowledged and growing importance. Strategy research, however, is only beginning to investigate the nature of networks and how network participation can affect organisational performance. Networks embody a relational view of the organisation and their study draws attention to the mechanisms by which relationships are secured and managed. Board of directors interlocks are a principal

  15. Modelling Railway Interlocking Tables using Coloured Petri Nets

    E-print Network

    Paris-Sud XI, Université de

    Modelling Railway Interlocking Tables using Coloured Petri Nets Somsak Vanit-Anunchai School, Railway Signalling Systems, State space analysis, XML, XSLT 1 Introduction Background Currently the State Railway of Thailand (SRT) has been under- taking several railway signalling projects involving either

  16. 58. Fair Street Interlocking & circuit breaker gantry. New Haven, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    58. Fair Street Interlocking & circuit breaker gantry. New Haven, New Haven Co., CT. Sec. 9108, MP 71.90. - Northeast Railroad Corridor, Amtrak Route between New York/Connecticut & Connecticut/Rhode Island State Lines, New Haven, New Haven County, CT

  17. How Does Learning Intent Affect Interlocking Directorates Dynamic?

    ERIC Educational Resources Information Center

    Simoni, Michele; Caiazza, Rosa

    2012-01-01

    Purpose: Literature on board interlocks agrees that these inter-organizational ties are effective channels to exchange information and share knowledge. However, studies that consider the nature and the amount of knowledge that firms exchange are still relatively absent. Filling this gap, this paper aims to identify four types of mechanisms that…

  18. 60. Fair Street Interlocking & circuit breaker gantry. New Haven, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    60. Fair Street Interlocking & circuit breaker gantry. New Haven, New Haven Co., CT. Sec. 9108, MP 71.90. - Northeast Railroad Corridor, Amtrak Route between New York/Connecticut & Connecticut/Rhode Island State Lines, New Haven, New Haven County, CT

  19. 59. Fair Street Interlocking & circuit breaker gantry. New Haven, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    59. Fair Street Interlocking & circuit breaker gantry. New Haven, New Haven Co., CT. Sec. 9108, MP 71.90. - Northeast Railroad Corridor, Amtrak Route between New York/Connecticut & Connecticut/Rhode Island State Lines, New Haven, New Haven County, CT

  20. A modification of the quadrant interlocking factorisation parallel method

    Microsoft Academic Search

    D. J. Evans; A. Hadjidimos

    1980-01-01

    A new factorisation method suitable for the solution of linear systems and determinant evaluation is proposed. The method is based on a modification of a factorisation recentlyproposed by Evans and Hatzopoulos [1] of the matrix in which interlocking matrix quadrant factors are considered in lieu of the (standard) well-known LU triangular factors. The method can be considered of Choleski type

  1. Automatic verification of safety interlock systems for industrial processes

    Microsoft Academic Search

    S. H. Yang; L. S. Tan; C. H. He

    2001-01-01

    The safety interlock system (SIS) is one of the most important protective measurements in industrial processes that provide automatic actions to correct an abnormal plant event. This paper considers the use of formal techniques based on symbolic model checking and computation tree logic (CTL) in the specification to automatically verify the SIS for industrial processes. It addresses the problem of

  2. Interlocked fabric and laminated fabric Kevlar 49/epoxy composites

    SciTech Connect

    Guess, T.R.; Reedy, E.D. Jr.

    1988-01-01

    The mechanical behavior of a novel interlocked fabric reinforced Kevlar 49/epoxy composite has been measured and compared to those of a laminated Kevlar 49 fabric composite (which served as a reference material). Both composites were 5.0 mm thick, contained the same 50% in-plane fiber volume fraction and were fabricated in a similar manner using the same Dow DER 332 epoxy, Jeffamine T403-hardened resin system. The reference material (Material 1) was reinforced with seven plies of Dupont style 1033 Kevlar 49 fabric. A photomicrograph of a section polished parallel to one of the fiber directions is shown. The interlocked fabric was designed and woven for Sandia National Laboratories by Albany International Research Co., Dedham, MA. The main design criterion was to duplicate a sewn through-the-thickness fabric used in preliminary studies. The interlocked fabric composite (Material 2) contains roughly 4% by volume of through-the-thickness fiber reinforcement for the purpose of improving interlaminar strength. A photomicrograph of a section showing the warp-aligned binder yarns interlocking the six fabric plies together is shown. 2 refs., 8 figs.

  3. Permeable Interlocking Concrete Pavement (PICP) for Stormwater Management

    E-print Network

    Permeable Interlocking Concrete Pavement (PICP) for Stormwater Management Benefits and Uses Traditional Concrete · Long-term Maintenance Required by Routine Vacuum Sweeping · Sweeping Cost May Be Off-set by Possible Reduction in Deicing Costs · Repairs Can be Made in Freezing Temperatures with Reinstated Concrete

  4. B & P Junction Substation & Interlocking Tower; Howard Street ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    B & P Junction Substation & Interlocking Tower; Howard Street Bridge. Baltimore, Baltimore City, MD. Sec. 1201, MP 95.85 - Northeast Railroad Corridor, Amtrak route between District of Columbia/Maryland state line & Maryland/Delaware state line, Baltimore, Independent City, MD

  5. Traumatic Distal Ulnar Artery Thrombosis

    PubMed Central

    Karaarslan, Ahmet A.; Karaka?l?, Ahmet; Mayda, Aslan; Karc?, Tolga; Aycan, Hakan; Kobak, ?enol

    2014-01-01

    This paper is about a posttraumatic distal ulnar artery thrombosis case that has occurred after a single blunt trauma. The ulnar artery thrombosis because of chronic trauma is a frequent condition (hypothenar hammer syndrome) but an ulnar artery thrombosis because of a single direct blunt trauma is rare. Our patient who has been affected by a single blunt trauma to his hand and developed ulnar artery thrombosis has been treated by resection of the thrombosed ulnar artery segment. This report shows that a single blunt trauma can cause distal ulnar artery thrombosis in the hand and it can be treated merely by thrombosed segment resection in suitable cases. PMID:25276455

  6. Evaluation of thoracic pedicle screw placement in adolescent idiopathic scoliosis

    PubMed Central

    Tosun, Bilgehan; Atmaca, Halil; Sarisoy, Hasan Tahsin; Buluç, Levent

    2009-01-01

    Pedicle screw fixation is a challenging procedure in thoracic spine, as inadvertently misplaced screws have high risk of complications. The accuracy of pedicle screws is typically defined as the screws axis being fully contained within the cortices of the pedicle. One hundred and eighty-five thoracic pedicle screws in 19 patients that were drawn from a total of 1.797 screws in 148 scoliosis patients being suspicious of medial and lateral malpositioning were investigated, retrospectively. Screw containment and the rate of misplacement were determined by postoperative axial CT sections. Medial screw malposition was measured between medial pedicle wall and medial margin of the pedicle screw. The distance between lateral margin of the pedicle screw and lateral vertebral corpus was measured in lateral malpositions. A screw that violated medially greater than 2 mm, while lateral violation greater than 6 mm was rated as an “unacceptable screw”. The malpositions were medial in 20 (10.8%) and lateral in 34 (18.3%) screws. Medially, nine screws were rated as acceptable. Of the 29 acceptable lateral misplacement, 13 showed significant risk; five to aorta, six to pleura, one to azygos vein and one to trachea. The acceptability of medial pedicle breach may change in each level with different canal width and a different amount of cord shift. In lateral acceptable malpositions, the aorta is always at a risk by concave-sided screws. This CT-based study demonstrated that T4–T9 concave segments have a smaller safe zone with respect to both cord-aorta injury in medial and lateral malpositions. In these segments, screws should be accurate and screw malposition is to be unacceptable. PMID:19526376

  7. Should we use cortical bone screws for cortical bone trajectory?

    PubMed

    Ueno, Masaki; Sakai, Rina; Tanaka, Kensei; Inoue, Gen; Uchida, Kentaro; Imura, Takayuki; Saito, Wataru; Nakazawa, Toshiyuki; Takahira, Naonobu; Mabuchi, Kiyoshi; Takaso, Masashi

    2015-04-01

    OBJECT In 2009, Santoni et al. reported cortical bone trajectory (CBT) as a method of inserting pedicle screws to obtain more solid fixation, and proposed the use of cortical trajectory screws with a more closely placed thread (cortical screws) for CBT. Since the entry trajectory in CBT differs from that in the traditional trajectory, it is unclear whether the increased strength derives from the specific trajectory or the shape of the screw thread in contact with the cortical bone. Whether the use of cortical screws is always required with CBT thus remains unclear. The authors therefore investigated the relationship between screw entry trajectory and screw thread characteristics and pullout strength in animal experiments. METHODS Lumbar vertebrae (L1-L4) from 4-month-old female pigs were randomly assigned to one of 4 groups, with cancellous screws or cortical screws inserted via the traditional trajectory or CBT. For pullout strength testing, the screw was pulled out vertically against the direction of insertion. Rod pullout testing (toggle testing) was also performed, and the peak breaking strength was measured. RESULTS The maximum pullout strength was significantly greater for CBT using cortical screws than for the traditional trajectory using cancellous screws. Pullout strength tended to be higher when cortical screws were used in both CBT and the traditional trajectory, although the difference was not significant. Toggle testing showed no significant differences among the 4 groups. CONCLUSIONS The specific unconventional trajectory seemed to have a major impact on the increased strength obtained with CBT. PMID:25594731

  8. Interlock system for machine protection of the KOMAC 100-MeV proton linac

    NASA Astrophysics Data System (ADS)

    Song, Young-Gi

    2015-02-01

    The 100-MeV proton linear accelerator of the Korea Multi-purpose Accelerator Complex (KOMAC) has been developed. The beam service started this year after performing the beam commissioning. If the very sensitive and essential equipment is to be protected during machine operation, a machine interlock system is required, and the interlock system has been implemented. The purpose of the interlock system is to shut off the beam when the radio-frequency (RF) and ion source are unstable or a beam loss occurs. The interlock signal of the KOMAC linac includes a variety of sources, such as the beam loss, RF and high-voltage converter modulator faults, and fast closing valves of the vacuum window at the beam lines and so on. This system consists of a hardware-based interlock system using analog circuits and a software-based interlock system using an industrial programmable logic controller (PLC). The hardware-based interlock system has been fabricated, and the requirement has been satisfied with the results being within 10 µs. The software logic interlock system using the PLC has been connected to the framework of with the experimental physics and industrial control system (EPICS) to integrate a variety of interlock signals and to control the machine components when an interlock occurs. This paper will describe the design and the construction of the machine interlock system for the KOMAC 100-MeV linac.

  9. We examine two pipeline structures which are employed in com mercial microprocessors. The first is the loaduse interlock (LUI)

    E-print Network

    Mudge, Trevor

    . The first is the load­use interlock (LUI) pipeline, which employs an interlock to ensure correct operation during load­use hazards. The second is the address­generation interlock (AGI) pipeline. It eliminates the load­use hazard, but has an address­generation hazard which requires an address­genera­ tion interlock

  10. arXiv:cs.CG/0410052v120Oct2004 A 2-CHAIN CAN INTERLOCK WITH A k-CHAIN

    E-print Network

    O'Rourke, Joseph

    arXiv:cs.CG/0410052v120Oct2004 A 2-CHAIN CAN INTERLOCK WITH A k-CHAIN JULIE GLASS, STEFAN LANGERMAN: what is the minimal number k such that an open, flexible k-chain can interlock with a flexible 2-chain interlocking. We prove that a flexible 2-chain can interlock with a flexible, open 16-chain. 1. Introduction

  11. Locking compression plate distal ulna hook plate as alternative fixation for fifth metatarsal base fracture.

    PubMed

    Lee, Sang Ki; Park, Ju Sang; Choy, Won Sik

    2014-01-01

    Intramedullary screw fixation has been the most common treatment for fifth metatarsal base fractures. However, screw application will not achieve accurate reduction in fractures with small fragments, osteoporotic bone, or Lawrence zone 1 fractures. Because of the similar anatomic architecture between the distal ulna and the fifth metatarsal base, the purpose of the present study was to assess the results of a locking compression plate distal ulna hook plate in stabilizing displaced zone 1 or 2 fifth metatarsal base fractures. A total of 19 patients with Lawrence zone 1 (n = 12) or 2 (n = 7) fractures of the fifth metatarsal base were treated surgically with a locking compression plate distal ulna hook plate. The patients were evaluated clinically and radiographically, and the functional outcomes were graded using the American Orthopaedic Foot and Ankle Society midfoot scoring system. Radiographic bony union was obtained in all patients, at an average of 7.4 weeks. The mean American Orthopaedic Foot and Ankle Society midfoot score improved from 26 (range 0 to 45) points preoperatively to 94 (range 72 to 100) points at the final follow-up visit. Three patients developed post-traumatic cubometatarsal arthrosis, and 1 patient developed sural nerve neurapraxia. In our experience, the distal ulna hook plate achieved a high rate of bony consolidation and anatomically suitable fixation in zone 1 or 2 fifth metatarsal base fractures. We suggest that the locking compression plate distal ulna hook plate should be considered as an alternative treatment of multifragmentary, osteoporotic, and tuberosity avulsion (zone 1) fifth metatarsal base fractures. PMID:24713494

  12. Screw expander for light duty diesel engines

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Preliminary selection and sizing of a positive displacement screw compressor-expander subsystem for a light-duty adiabatic diesel engine; development of a mathematical model to describe overall efficiencies for the screw compressor and expander; simulation of operation to establish overall efficiency for a range of design parameters and at given engine operating points; simulation to establish potential net power output at light-duty diesel operating points; analytical determination of mass moments of inertia for the rotors and inertia of the compressor-expander subsystem; and preparation of engineering layout drawings of the compressor and expander are discussed. As a result of this work, it was concluded that the screw compressor and expander designed for light-duty diesel engine applications are viable alternatives to turbo-compound systems, with acceptable efficiencies for both units, and only a moderate effect on the transient response.

  13. Rotary screw compressors in the gas patch

    SciTech Connect

    Jandjel, D.G.

    1996-01-01

    In 1959, Howden introduced the oil-injected rotary screw (OIS) compressor, which has, since then, methodically replaced the reciprocating (piston) compressor in applications such as air, refrigeration and fuel gas. Rotary screw compressors have been making inroads in gas recovery, a field once dominated by reciprocating compressors. Rotary screws do not require extensive maintenance, thus downtime is minimized throughout an operating year. Preventive maintenance is simple, since it consists of regular oil sample analysis which does not require system shut-down. As a result of the slide valve, OIS compressors can tune to field conditions with the greatest of ease, and without complicated process control. In addition, this method of capacity control is more efficient than unloading or use of a bypass-recirculation line. Both engineers and operators alike have found this flexibility to be a most redeeming feature. Finally, OIS compressors are capable of much larger flows then recips. 2 figs.

  14. Low energy high pressure miniature screw valve

    DOEpatents

    Fischer, Gary J. (Sandia Park, NM); Spletzer, Barry L. (Albuquerque, NM)

    2006-12-12

    A low energy high pressure screw valve having a valve body having an upper portion and a lower portion, said lower portion of said valve body defining an inlet flow passage and an outlet flow passage traversing said valve body to a valve seat, said upper portion of said valve body defining a cavity at said valve seat, a diaphragm restricting flow between said upper portion of said valve body and said lower portion, said diaphragm capable of engaging said valve seat to restrict fluid communication between said inlet passage and said outlet passage, a plunger within said cavity supporting said diaphragm, said plunger being capable of engaging said diaphragm with said valve seat at said inlet and outlet fluid passages, said plunger being in point contact with a drive screw having threads engaged with opposing threads within said upper portion of said valve body such engagement allowing motion of said drive screw within said valve body.

  15. Impact of screw configuration on the particle size distribution of granules produced by twin screw granulation.

    PubMed

    Vercruysse, J; Burggraeve, A; Fonteyne, M; Cappuyns, P; Delaet, U; Van Assche, I; De Beer, T; Remon, J P; Vervaet, C

    2015-02-01

    Twin screw granulation (TSG) has been reported by different research groups as an attractive technology for continuous wet granulation. However, in contrast to fluidized bed granulation, granules produced via this technique typically have a wide and multimodal particle size distribution (PSD), resulting in suboptimal flow properties. The aim of the current study was to evaluate the impact of granulator screw configuration on the PSD of granules produced by TSG. Experiments were performed using a 25 mm co-rotating twin screw granulator, being part of the ConsiGma™-25 system (a fully continuous from-powder-to-tablet manufacturing line from GEA Pharma Systems). Besides the screw elements conventionally used for TSG (conveying and kneading elements), alternative designs of screw elements (tooth-mixing-elements (TME), screw mixing elements (SME) and cutters) were investigated using an ?-lactose monohydrate formulation granulated with distilled water. Granulation with only conveying elements resulted in wide and multimodal PSD. Using kneading elements, the width of the PSD could be partially narrowed and the liquid distribution was more homogeneous. However, still a significant fraction of oversized agglomerates was obtained. Implementing additional kneading elements or cutters in the final section of the screw configuration was not beneficial. Furthermore, granulation with only TME or SME had limited impact on the width of the PSD. Promising results were obtained by combining kneading elements with SME, as for these configurations the PSD was narrower and shifted to the size fractions suitable for tableting. PMID:25562758

  16. 21 CFR 888.3070 - Pedicle screw spinal system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3070 Pedicle screw spinal system. (a) Identification. Pedicle screw spinal systems...

  17. Spline-Screw Multiple-Rotation Mechanism

    NASA Technical Reports Server (NTRS)

    Vranish, John M.

    1994-01-01

    Mechanism functions like combined robotic gripper and nut runner. Spline-screw multiple-rotation mechanism related to spline-screw payload-fastening system described in (GSC-13454). Incorporated as subsystem in alternative version of system. Mechanism functions like combination of robotic gripper and nut runner; provides both secure grip and rotary actuation of other parts of system. Used in system in which no need to make or break electrical connections to payload during robotic installation or removal of payload. More complicated version needed to make and break electrical connections. Mechanism mounted in payload.

  18. Intramedullary screw fixation with bone autografting to treat proximal fifth metatarsal metaphyseal-diaphyseal fracture in athletes: a case series

    PubMed Central

    2012-01-01

    Background Delayed unions or refractures are not rare following surgical treatment for proximal fifth metatarsal metaphyseal-diaphyseal fractures. Intramedullary screw fixation with bone autografting has the potential to resolve the issue. The purpose of this study was to evaluate the result of the procedure. Methods The authors retrospectively reviewed 15 athletes who underwent surgical treatment for proximal fifth metatarsal metaphyseal-diaphyseal fracture. Surgery involved intramedullary cannulated cancellous screw fixation after curettage of the fracture site, followed by bone autografting. Postoperatively, patients remain non weight-bearing in a splint or cast for two weeks and without immobilization for an additional two weeks. Full weight-bearing was allowed six weeks postoperatively. Running was permitted after radiographic bone union, and return-to-play was approved after gradually increasing the intensity. Results All patients returned to their previous level of athletic competition. Mean times to bone union, initiation of running, and return-to-play were 8.4, 8.8, and 12.1?weeks, respectively. Although no delayed unions or refractures was observed, distal diaphyseal stress fractures at the distal tip of the screw occurred in two patients and a thermal necrosis of skin occurred in one patient. Conclusions There were no delayed unions or refractures among patients after carrying out a procedure in which bone grafts were routinely performed, combined with adequate periods of immobilization and non weight-bearing. These findings suggest that this procedure may be useful option for athletes to assuring return to competition level. PMID:22818585

  19. Outcome Assessment after Aptis Distal Radioulnar Joint (DRUJ) Implant Arthroplasty

    PubMed Central

    Kachooei, Amir Reza; Chase, Samantha M; Jupiter, Jesse B

    2014-01-01

    Background: Conventional treatments after complicated injuries of the distal radioulnar joint (DRUJ) such as Darrach and Kapandji-Sauvé procedures have many drawbacks, which may eventually lead to a painful unstable distal ulna. The development of DRUJ prosthesis has significantly evolved over the past years. In this study, we assessed the outcome results of patients after DRUJ implant arthroplasty using the Aptis (Scheker) prosthesis. Methods: We identified 13 patients with 14 prosthesis during the past 10 years. Patients underwent DRUJ arthroplasty due to persistent symptoms of instability, chronic pain, and stiffness. Records and follow-up visits were reviewed to find the final post-operative symptoms, pain, range of motion, and grip strength with a mean follow-up of 12 months (range: 2-25 months). Also, patients were contacted prospectively by phone in order to administer the disabilities of the arm shoulder and hand (DASH), patient rated wrist evaluation (PRWE), and visual analogue scale (VAS), and to interview regarding satisfaction and progress in daily activities. Eleven patients out of 13 could be reached with a median follow-up time of 60 months (range: 2 to 102 months). Results: No patient required removal of the prosthesis. Only two patients underwent secondary surgeries in which both required debridement of the screw tip over the radius. The median DASH score, PRWE score, VAS, and satisfaction were 1.3, 2.5, 0, and 10, respectively. The mean range of flexion, extension, supination, and pronation was 62, 54, 51, and 64, respectively. Conclusions: Distal radioulnar joint injuries are disabling and patients usually undergo one or more salvage surgeries prior to receiving an arthroplasty. The Scheker prosthesis has shown satisfactory results with 100% survival rate in all reports. The constrained design of this prosthesis gives enough stability to prevent painful subluxation. PMID:25386579

  20. A Novel Pedicle Screw with Mobile Connection: A Pilot Study

    PubMed Central

    Oshima, Masashi; Ajiro, Yasumitsu; Uei, Hiroshi

    2014-01-01

    To prevent adjacent disc problems after spinal fusion, a pedicle screw with a mobile junction between the head and threaded shaft was newly developed. The threaded shaft of the screw has 10 degrees mobility in all directions, but its structure is to prevent abnormal translation and tilting. This screw was evaluated as follows: (1) endurance test: 106 times rotational stress was applied; (2) biological reactions: novel screws with a mobile head and conventional screws with a fixed head were inserted into the bilateral pedicles of the L3, L4, and L5 in two mini pigs with combination. Eight months after surgery, vertebral units with the screw rod constructs were collected. After CT scan, the soft and bony tissues around the screws were examined grossly and histologically. As a result, none of the screws broke during the endurance test stressing. The mean amount of abrasion wear was 0.0338?g. In the resected mini pig section, though zygapophyseal joints between fixed-head screws showed bony union, the amount of callus in the zygapophyseal joints connected with mobile-head screws was small, and joint space was confirmed by CT. No metalloses were noted around any of the screws. Novel screws were suggested to be highly durable and histologically safe. PMID:24724103

  1. Distal Oblique Bundle Reconstruction and Distal Radioulnar Joint Instability

    PubMed Central

    Riggenbach, Michael D.; Conrad, Bryan P.; Wright, Thomas W.; Dell, Paul C.

    2013-01-01

    Background?This study created an anatomic reconstruction of the distal oblique bundle (DOB) of the interosseous membrane to determine its effect on distal radioulnar joint (DRUJ) instability and compare this technique with distal radioulnar ligament (DRUL) reconstruction. Questions/Purposes?We hypothesized that this reconstruction would provide equivalent stability to DRUL reconstruction and that combining the two techniques would enhance stability. Methods?Six cadaveric upper limbs were affixed to a custom frame. The volar/dorsal translation of the radius relative to the ulna was measured in 60° pronation, neutral, and 60° supination. Translation was sequentially measured with the DRUJ intact, with sectioned DRULs and triangular fibrocartilaginous complex (TFCC), and with sectioned DOBs. Reconstructions were performed on the DRULs, on the DOB tensioned in both neutral and supination, and employing both techniques. Results?The DOB reconstruction, tensioned both in the neutral position and in 60° supination, was more stable than the partial and complete instability in 6/6 specimens in pronation and the neutral position and in 5/6 specimens in supination. The DOB reconstruction and the DOB reconstruction tensioned in supination were more stable than the DRUL reconstruction in 4/6 patients. Combining the two techniques did not further reduce translation. Conclusions?The DOB reconstruction is capable of improving stability in the unstable DRUJ. PMID:24436838

  2. Nylon screws make inexpensive coil forms

    NASA Technical Reports Server (NTRS)

    Aucoin, G.; Rosenthal, C.

    1978-01-01

    Standard nylon screws act as coil form copper wire laid down in spiral thread. Completed coil may be bonded to printed-circuit board. However, it is impossible to tune coil by adjusting spacing between windings, technique sometimes used with air-core coils.

  3. Semi-Empirical Screw Compressor Chiller Model

    E-print Network

    Nelson, I. C.; Culp, C.; Graves, R. D.

    and kW/ton with an accuracy of 4-7% when compared to the 4,104 data points acquired from a screw chiller system. The semi-empirical chiller model results were also compared to the Gordon-Ng model predictions as a function of the percentage chiller...

  4. High Bandwidth Control of Ball Screw Drives

    Microsoft Academic Search

    K. Erkorkmaz; A. Kamalzadeh

    2006-01-01

    This paper presents a tracking control strategy for high speed ball screw drives. Rigid body motion is controlled using adaptive sliding mode control. Torsional vibrations are modeled, experimentally identified, and compensated in the control law using notch filtering and active cancellation techniques. Attenuation of torsional resonances improves the stability margins and enables high positioning bandwidth to be achieved. The axis

  5. Improvements In Ball-Screw Linear Actuators

    NASA Technical Reports Server (NTRS)

    Iskenderian, Theodore; Joffe, Benjamin; Summers, Robert

    1996-01-01

    Report describes modifications of design of type of ball-screw linear actuator driven by dc motor, with linear-displacement feedback via linear variable-differential transformer (LVDT). Actuators used to position spacecraft engines to direct thrust. Modifications directed toward ensuring reliable and predictable operation during planned 12-year cruise and interval of hard use at end of cruise.

  6. Radiographic study of iliac screw passages

    PubMed Central

    2014-01-01

    Background The optimal iliac screw path was determined to provide references for lumbosacral-pelvic reconstruction. Methods Radiographic data of 100 patients with normal pelvis were selected for this study. Four paths were designed. Paths A, B, and C were from the starting point of the crossing point of the chiotic line and posterior iliac crest (CLIC, located at 24.0 mm above the posterior superior iliac spine) to the upper edge of the acetabulum, anterior inferior iliac spine, and acetabulum center, respectively. Path D was from the starting point of the posterior superior iliac spine to the anterior inferior iliac spine. The lengths of the different paths of screw passage and bone plate thicknesses of two narrow places were measured and analyzed. Results Paths A, B, and D were approximately equal in length, but the thickness of the iliac plate in path A was significantly thicker than those in paths B and D. No significant difference was found between the iliac thickness of paths A and C, but the passage length of path A was significantly longer than that of path C. Conclusion Path A had the longest passage length and thickest iliac plate and could accommodate the relatively longest and thickest iliac screw. Thus, path A was the optimal iliac screw passage. PMID:24885171

  7. COMPRESSION LOAD TRANSMISSION IN SCREW COMPRESSORS

    Microsoft Academic Search

    G. P. Adams; Z. H. Qin

    1997-01-01

    In the current investigations of the bearing forces in screw compressors, the supports at the bearings are basically treated as ideal, simply supported boundary conditions. By using statics theory, the loads on the rotors are converted to the bearings at the suction and discharge ends. Some studies on rotor dynamics have shown that the behaviors of a rotor bearing system

  8. Calculation of Rotor Interference in Screw Compressors

    Microsoft Academic Search

    N. Stosic; Ian K. Smith; A. Kovacevic

    Small rotor clearances are today a vital prerequisite for an efficient screw compressor. The clearances are responsible for compressor leakages, small clearance will minimise them and thereby increase both, the volumetric and adiabatic efficiency. A continuous improvement in the rotor manufacturing equipment has been achieved during the recent years and tight production tolerances may now be applied to compressor rotors.

  9. Improvements to the single screw extruder

    NASA Technical Reports Server (NTRS)

    Hiemenz, C.; Ziegmann, G.; Franzkoch, B.; Hoffmanns, W.; Michaeli, W.

    1977-01-01

    The extrusion on a single screw extruder is examined. The process is divided into several steps: the dosage of the materials to be conveyed; the modification of the shape of the feeding opening which influences the feeding process and consequently the throughput of the extruder; optimizing the shape of the feeding zone to meet the specific material requirements; and plasticizing and homogenizing.

  10. Engineering interlocking DNA rings with weak physical interactions

    NASA Astrophysics Data System (ADS)

    Wu, Zai-Sheng; Shen, Zhifa; Tram, Kha; Li, Yingfu

    2014-06-01

    Catenanes are intriguing molecular assemblies for engineering unique molecular devices. The resident rings of a catenane are expected to execute unhindered rotation around each other, and to do so, they must have weak physical interactions with each other. Due to sequence programmability, DNA has become a popular material for nanoscale object engineering. However, current DNA catenanes, particularly in the single-stranded (ss) form, are synthesized through the formation of a linking duplex, which makes them less ideal as mobile elements for molecular machines. Herein we adopt a random library approach to engineer ssDNA [2] catenanes (two interlocked DNA rings) without a linking duplex. Results from DNA hybridization, double-stranded catenane synthesis and rolling circle amplification experiments signify that representative catenanes have weak physical interactions and are capable of operating as independent units. Our findings lay the foundation for exploring free-functioning interlocked DNA rings for the design of elaborate nanoscale machines based on DNA.

  11. NATIONAL SYNCHROTRON LIGHT SOURCE MEDICAL PERSONNEL PROTECTION INTERLOCK

    SciTech Connect

    BUDA,S.; GMUR,N.F.; LARSON,R.; THOMLINSON,W.

    1998-11-03

    This report is founded on reports written in April 1987 by Robert Hettel for angiography operations at the Stanford Synchrotron Research Laboratory (SSRL) and a subsequent report covering angiography operations at the National Synchrotron Light Source (NSLS); BNL Informal Report 47681, June 1992. The latter report has now been rewritten in order to accurately reflect the design and installation of a new medical safety system at the NSLS X17B2 beamline Synchrotron Medical Research Facility (SMERF). Known originally as the Angiography Personnel Protection Interlock (APPI), this system has been modified to incorporate other medical imaging research programs on the same beamline and thus the name has been changed to the more generic Medical Personnel Protection Interlock (MPPI). This report will deal almost exclusively with the human imaging (angiography, bronchography, mammography) aspects of the safety system, but will briefly explain the modular aspects of the system allowing other medical experiments to be incorporated.

  12. Metal-organic frameworks with dynamic interlocked components

    NASA Astrophysics Data System (ADS)

    Vukotic, V. Nicholas; Harris, Kristopher J.; Zhu, Kelong; Schurko, Robert W.; Loeb, Stephen J.

    2012-06-01

    The dynamics of mechanically interlocked molecules such as rotaxanes and catenanes have been studied in solution as examples of rudimentary molecular switches and machines, but in this medium, the molecules are randomly dispersed and their motion incoherent. As a strategy for achieving a higher level of molecular organization, we have constructed a metal-organic framework material using a [2]rotaxane as the organic linker and binuclear Cu(II) units as the nodes. Activation of the as-synthesized material creates a void space inside the rigid framework that allows the soft macrocyclic ring of the [2]rotaxane to rotate rapidly, unimpeded by neighbouring molecular components. Variable-temperature 13C and 2H solid-state NMR experiments are used to characterize the nature and rate of the dynamic processes occurring inside this unique material. These results provide a blueprint for the future creation of solid-state molecular switches and molecular machines based on mechanically interlocked molecules.

  13. [Accuracy of fluoroscopic navigation of pedicle screws. CT-based evaluation of bone screw placement].

    PubMed

    Fritsch, E; Duchow, J; Seil, R; Grunwald, I; Reith, W

    2002-04-01

    While the advantages of C-arm navigation in computer-assisted spine surgery are obvious, the accuracy of pedicle screw placement with virtual fluoroscopy still needs to be verified. The C-arm-based ION system (Medtronic Sofamor Danek) was used to navigate pedicle screw insertion in patients undergoing spinal surgery for various conditions. In a prospective study, a total of 160 screws were inserted in the first 30 consecutive patients since introduction of the system at our institution: 54 at the thoracic spine (highest level: TH4) and 106 at the lumbar spine. Computed tomography (CT) scans were performed postoperatively by two independent radiologists to control the accuracy of screw placement at the level of the pedicles after reconstruction of axial images according to Laine et al. The comparison of the calculated accuracy rate of pedicle screw placement using virtual fluoroscopy with reported results achieved with CT-based navigation shows similar results for virtual fluoroscopy and a remarkable increase of accuracy in comparison to reports on conventional pedicle screw placement. PMID:12056280

  14. 116. Photocopied August 1978. NEW INTERLOCKING STEEL SHEET PILING AT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    116. Photocopied August 1978. NEW INTERLOCKING STEEL SHEET PILING AT PENSTOCK 52 IN THE FALL OF 1926. THE PILES FOR SUPPORTING THE HORIZONTAL ELEMENTS OF THE NEW FOREBAY APRON ARE IN PLACE BETWEEN THE NEW SHEET PILING AND THE FOREBAY WALL. VISIBLE BEYOND THE NEW SHEET PILING IS THE TIMBER SHEET PILING DRIVEN IN 1903 BY VON SCHON TO PREVENT WASHOUTS. (1006) - Michigan Lake Superior Power Company, Portage Street, Sault Ste. Marie, Chippewa County, MI

  15. Formal Verification of a Railway Interlocking System using Model Checking

    Microsoft Academic Search

    Alessandro Cimatti; Fausto Giunchiglia; Giorgio Mongardi; Dario Romano; Fernando Torielli; Paolo Traverso

    1998-01-01

    .   In this paper we describe an industrial application of formal methods. We have used model checking techniques to model and\\u000a formally verify a rather complex software, i.e. part of the “safety logic” of a railway interlocking system. The formal model\\u000a is structured to retain the reusability and scalability properties of the system being modelled. Part of it is defined

  16. Biomechanical analysis of the mechanism of interlocking nail failure

    Microsoft Academic Search

    Chi-Chuan Wu; Chun-Hsiung Shih

    1992-01-01

    From December 1986 to May 1989, 412 patients with 274 femoral and 144 tibial fractures were treated with Grosse-Kempf interlocking nails at our hospital. 324 cases (78.6%) were followed-up for at least 1 year (average 23 months). There were 13 breakages in the locking nails in femora and none in tibiae. The recorded incidence of breakage in the femur is

  17. Interlocking compression nailing: a report on 402 applications

    Microsoft Academic Search

    O. Gonschorek; G. O. Hofmann; V. Bühren

    1998-01-01

    Nailing techniques have changed tremendously in recent years. One significant development has been the interlocking compression\\u000a nail (ICN) which provides active interfragmentary compression. Apart from its beneficial effect in the treatment of acute\\u000a fractures, allowing early weight-bearing and mobilization of the patient the ICN is useful in many types of revision operations:\\u000a resection and stabilization of pseudarthroses without cancellous bone

  18. Interlock and control systems for a sector at the APS

    SciTech Connect

    Friedman, N.

    1993-09-09

    This report describes some basic elements of the various Interlock and Control Systems associated with the Front Ends and Beamlines. Some systems serve only the Front Ends; other serve both the Front Ends and the Beamlines, while the Experimental Controls are for the Beamlines only. Specific system requirements and design specifications are not in the scope of this report. They will be presented in the descriptions of the Experimental Floor Personnel Safety System (XF-PSS or, more often, PSS) and Equipment Protection System (XF-EPS or EPS), which will expand on the overview presented here. The main focus here is on the PSS and EPS in the context of their interactions and interface to the Storage Ring Access Control Interlock System (ACIS), and Ring Controls. The other systems are only mentioned to make the cross section complete. This paper is the first in series of three reports that jointly provide a full description of sector interlocks. The second report describes the PSS, and the third -- the EPS.

  19. Distal Tibial Fractures: Intramedullary Nailing

    Microsoft Academic Search

    Andreas H. Ruecker; Michael Hoffmann; Martin E. Rupprecht; Johannes M. Rueger

    2009-01-01

    \\u000a Abstract\\u000a   The tibia is an exposed bone with vulnerable soft tissue coverage and is therefore predisposed to local soft tissue problems\\u000a and delayed bone healing. The objective in distal tibial fracture treatment is to achieve stable fixation patterns with a\\u000a minimum of soft-tissue affection. Thus, the risk of soft tissue breakdown and bone healing complications is more likely related\\u000a to

  20. Surgical screw segmentation for mobile C-arm CT devices

    NASA Astrophysics Data System (ADS)

    Görres, Joseph; Brehler, Michael; Franke, Jochen; Wolf, Ivo; Vetter, Sven Y.; Grützner, Paul A.; Meinzer, Hans-Peter; Nabers, Diana

    2014-03-01

    Calcaneal fractures are commonly treated by open reduction and internal fixation. An anatomical reconstruction of involved joints is mandatory to prevent cartilage damage and premature arthritis. In order to avoid intraarticular screw placements, the use of mobile C-arm CT devices is required. However, for analyzing the screw placement in detail, a time-consuming human-computer interaction is necessary to navigate through 3D images and therefore to view a single screw in detail. Established interaction procedures of repeatedly positioning and rotating sectional planes are inconvenient and impede the intraoperative assessment of the screw positioning. To simplify the interaction with 3D images, we propose an automatic screw segmentation that allows for an immediate selection of relevant sectional planes. Our algorithm consists of three major steps. At first, cylindrical characteristics are determined from local gradient structures with the help of RANSAC. In a second step, a DBScan clustering algorithm is applied to group similar cylinder characteristics. Each detected cluster represents a screw, whose determined location is then refined by a cylinder-to-image registration in a third step. Our evaluation with 309 screws in 50 images shows robust and precise results. The algorithm detected 98% (303) of the screws correctly. Thirteen clusters led to falsely identified screws. The mean distance error for the screw tip was 0.8 +/- 0.8 mm and for the screw head 1.2 +/- 1 mm. The mean orientation error was 1.4 +/- 1.2 degrees.

  1. Translaminar screw fixation in the subaxial pediatric cervical spine.

    PubMed

    Jea, Andrew; Johnson, Keyne K; Whitehead, William E; Luerssen, Thomas G

    2008-12-01

    The use of spinal instrumentation to stabilize the occipitocervical junction in pediatric patients has increased and evolved in recent years. Wiring techniques have now given way to screw-rod or screw-plate techniques with or without postoperative external immobilization. Although C-2 translaminar screws have been used in these constructs, subaxial translaminar screws have not, to date, been described in either the pediatric or adult patient populations. The authors describe the feasibility of translaminar screw placement in the C-3 lamina. Rigid fixation with translaminar screws offers an alternative to subaxial fixation with lateral mass screws, allowing for formation of biomechanically sound spinal constructs and minimizing potential neurovascular morbidity. Their use requires careful analysis of preoperative imaging studies, intact posterior elements, and avoidance of violation of the inner laminar wall. PMID:19035682

  2. Model-Based Generation of Interlocking Controller Software from Control Tables

    Microsoft Academic Search

    Cédric Chevillat; Paul A. Strooper; Jörn Guy Süß; Luke Wildman

    2008-01-01

    Railroad interlocking software drives specialised micro-devices, known as interlocking controllers. These controllers primarily\\u000a actuate railroad points and change signal aspects in real-time, based on sensor and timer input. Due to their central function\\u000a in railroad control, interlocking controllers and their firmware are safety-critical. The firmware programs, which mimic physical\\u000a relays, are written in variants of domain-specific programming languages based on

  3. Porous hydroxyapatite ceramics and their ability to be fixed by commercially available screws

    Microsoft Academic Search

    M. D. Ichiro Ono; M. D. Tohru Tateshita; Takehiko Nakajima

    1999-01-01

    We developed porous hydroxyapatite ceramics (HAP) which are screw fixable and evaluated the fixing abilities of commercially available screws using pull-out tests with the HAP implants. The fixing abilities were higher in the following order: Leibinger micro PLUS titanium screw>Osteomed M3 titanium screw>Leibinger standard mini screw>Martin-drill free screw. In preliminary examinations, the fixing ability of each of the screws differed

  4. 46 CFR 111.70-7 - Remote control, interlock, and indicator circuits.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Motor...the current-carrying capacity of the control, electrical interlock, or indicator circuit...

  5. 46 CFR 111.70-7 - Remote control, interlock, and indicator circuits.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Motor...the current-carrying capacity of the control, electrical interlock, or indicator circuit...

  6. 46 CFR 111.70-7 - Remote control, interlock, and indicator circuits.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Motor...the current-carrying capacity of the control, electrical interlock, or indicator circuit...

  7. Clinical application of C2 laminar screw technique

    PubMed Central

    Feng, Leling; Xu, Rongming; Liu, Xiaochen; Lee, Alan H.; Sun, Shaohua; Zhao, Liujun; Hu, Yong; Liu, Guanyi

    2010-01-01

    C2 laminar screws have become an increasingly used alternative method to C2 pedicle screw fixation. However, the outcome of this technique has not been thoroughly investigated. A total of 35 cases with upper cervical spinal instability undergoing C2 laminar screw fixation were reviewed. All cases had symptoms of atlantoaxial instability, such as craniocervical junction pain, and were fixed with the Vertex cervical internal fixation system. A total of 68 screws were placed and hybrid constructs (a C2 translaminar screw combined with a C2 pars screw) were incorporated in two patients. In this series, there were no intraoperative complications and no cases of neurological worsening or vascular injury from hardware placement. Computed tomographic scans demonstrated a partial dorsal laminar breach in ten patients. None of these resulted in neurological symptoms. None of the patients was found to have a breach of the ventral laminar cortex. All the C2 laminar screws fixations were performed successfully. There was no instability seen on the films with no evidence of hardware failure or screw loosening during the follow-up period in all patients. In conclusion, C2 laminar screw technique is straightforward and easily adopted; it can efficiently and reliably restore upper cervical stability. It is an alternative method to C2 pedicle screw fixation, especially in patients with unilateral occlusion of vertebral artery and pedicle deformity of C2. PMID:20524135

  8. DNA and the 'magic rings' trick (PhysOrg.com) --A new study from UC Davis shows how, like a conjuring trick with interlocking

    E-print Network

    Kowalczykowski, Stephen C.

    a conjuring trick with interlocking rings, two interlocked pieces of DNA are separated after DNA is copied, the chromosomes have to separate -- like the magician's interlocking rings, one has to pass through the other

  9. Compression Load Transmission in Screw Compressors

    NASA Astrophysics Data System (ADS)

    Adams, G. P.; Qin, Z. H.

    1997-11-01

    In the current investigations of the bearing forces in screw compressors, the supports at the bearings are basically treated as ideal, simply supported boundary conditions. By using statics theory, the loads on the rotors are converted to the bearings at the suction and discharge ends. Some studies on rotor dynamics have shown that the behaviors of a rotor bearing system are, to some extent, controlled by the bearings that support the rotor. Therefore, it is important to study the dynamic performance of the rotor bearing system in screw compressors so that the bearing forces can be more accurately described. In this paper, a numerical method is presented for computing the compression loads by integrating the pressure over the rotor surface. Vector calculus and numerical integration methods are implemented to calculate the compression loads in order to obtain a robust procedure that can be applied to arbitrary rotor profiles. In addition, a dynamic model of a rigid compressor rotor supported by two cylindrical roller bearings and a four point contact ball bearing is developed from basic principles. This model simulates the dynamic responses of a typical screw compressor configuration. It includes five degrees of freedom of rotor motion interacting with the bearings of non-linear characteristics. Under the compression loads, the resulting bearing forces in the screw compressor are compared with those obtained by assuming ideal, simply supported boundary conditions at the bearings. It is shown that the interactions between the rotor and bearings are quite different by coupling the global rotor motion with the local dynamics of the bearings.

  10. Direct Arthroscopic Distal Clavicle Resection

    PubMed Central

    Lervick, Gregory N

    2005-01-01

    Degenerative change involving the acromioclavicular (AC) is frequently seen as part of a normal aging process. Occasionally, this results in a painful clinical condition. Although AC joint symptoms commonly occur in conjunction with other shoulder pathology, they may occur in isolation. Treatment of isolated AC joint osteoarthritis is initially non-surgical. When such treatment fails to provide lasting relief, surgical treatment is warranted. Direct (superior) arthroscopic resection of the distal (lateral) end of the clavicle is a successful method of treating the condition, as well as other isolated conditions of the AC joint. The following article reviews appropriate patient evaluation, surgical indications and technique. PMID:16089089

  11. [Analysis of tendon injuries accompanying distal radius fractures using volar locking plates].

    PubMed

    Zenke, Yukichi; Oshige, Toshihisa; Menuki, Kunitaka; Yamanaka, Yoshiaki; Murai, Teppei; Furukawa, Kayoko; Sakai, Akinori

    2014-12-01

    We examined 6 cases of tendon injuries that accompanied distal radius fractures using volar locking plate between April 2006 and March 2012. Male: one case, female: five cases, average age 57.0 (33~70) years old. The fracture type was A2 in one case, A3 in four cases, and C2 in one case by AO classification. The average period for operation waiting was 2.7 days. We analyzed the time of occurrence of tendon rupture (extensor pollicis longus (EPL)?flexor pollicis longus (FPL)), the existence or not of screw prominence and dorsal roof fragment, and the positioning of the plate setting. The tendon ruptures were EPL in four cases, and FPL in two cases. The average period of rupture occurrence was 86.8 (1~182) days. In four EPL tendon ruptures we recognized one marked screw prominence (16.7%), and two dorsal roof fragments (50%), both showing widespread displacement. Moreover, we recognized the malposition of the plate setting in the two cases of FPL tendon rupture (100%). The incidence of tendon ruptures accompanying distal radius fractures using volar locking plates was not low at all, therefore we should more pay attention to the prevention of this occurrence. PMID:25501757

  12. Intraoperative 3-dimensional imaging (O-arm) for assessment of pedicle screw position: Does it prevent unacceptable screw placement?

    PubMed Central

    Sembrano, Jonathan N.; Polly, David W.; Ledonio, Charles Gerald T.; Santos, Edward Rainier G.

    2012-01-01

    Background Pedicle screws are biomechanically superior over other spinal fixation devices. When improperly positioned, they lose this advantage and put adjacent structures at risk. Accurate placement is therefore critical. Postoperative computed tomography (CT) scans are the imaging gold standard and have shown malposition rates ranging from 2% to 41%. The O-arm (Medtronic Navigation, Louisville, Colorado) is an intraoperative CT scanner that may allow intervention for malpositioned screws while patients are still in the operating room. However, this has not yet been shown in clinical studies. The primary objective of this study was to assess the usefulness of the O-arm for evaluating pedicle screw position by answering the following question: What is the rate of intraoperative pedicle screw revision brought about by O-arm imaging information? A secondary question was also addressed: What is the rate of unacceptable thoracic and lumbar pedicle screw placement as assessed by intraoperative O-arm imaging? Methods This is a case series of consecutive patients who have undergone spine surgery for which an intraoperative 3-dimensional (3D) CT scan was used to assess pedicle screw position. The study comprised 602 pedicle screws (235 thoracic and 367 lumbar/sacral) placed in 76 patients, and intraoperative 3D (O-arm) imaging was obtained to assess screw position. Action taken at the time of surgery based on imaging information was noted. An independent review of all scans was also conducted, and all screws were graded as either optimal (no breach), acceptable (breach ?2 mm), or unacceptable (breach >2 mm). The rate of pedicle screw revision, as detected by intraoperative 3D CT scan, was determined. Results On the basis of 3D imaging information, 17 of 602 screws (2.8%) in 14 of 76 cases (18.4%) were revised at the time of surgery. On independent review of multiplanar images, 11 screws (1.8%) were found to be unacceptable, 32 (5.3%) were acceptable, and 559 (92.9%) were optimal. All unacceptable screws were revised to an optimal or acceptable position, and an additional 6 acceptable screws were revised to an optimal position. Thus, by the end of the cases, none of the 602 pedicle screws in the 76 surgical procedures was in an unacceptable position. Conclusion The new-generation intraoperative 3D imaging system (O-arm) is a useful tool that allows more accurate assessment of pedicle screw position than plain radiographs or fluoroscopy alone. It prompted intraoperative repositioning of 2.8% of pedicle screws in our series. Most importantly, it allowed identification and revision of all unacceptably placed pedicle screws without the need for reoperation. PMID:25694871

  13. National Synchrotron Light Source medical personnel protection interlock

    SciTech Connect

    Buda, S.; Gmuer, N.F.; Larson, R.; Thomlinson, W.

    1998-11-01

    This report is founded on reports written in April 1987 by Robert Hettel for angiography operations at the Stanford Synchrotron Research Laboratory (SSRL) and a subsequent report covering angiography operations at the National Synchrotron Light Source (NSLS); BNL Informal Report 47681, June 1992. The latter report has now been rewritten in order to accurately reflect the design and installation of a new medical safety system at the NSLS X17B2 beamline Synchrotron Medical Research Facility (SMERF). Known originally as the Angiography Personnel Protection Interlock (APPI), this system has been modified to incorporate other medical imaging research programs on the same beamline and thus the name has been changed to the more generic Medical Personnel Protection Interlock (MPPI). This report will deal almost exclusively with the human imaging (angiography, bronchography, mammography) aspects of the safety system, but will briefly explain the modular aspects of the system allowing other medical experiments to be incorporated. This MPPI report is organized such that the level of detail changes from a general overview to detailed engineering drawings of the hardware system. The general overview is presented in Section 1.0, MPPI Operational Mode and Procedures. The various MPPI components are described in detail in Section 2.0. Section 3.0 presents some simplified logic diagrams and accompanying text. This section was written to allow readers to become familiar with the logic system without having to work through the entire set of detailed engineering drawings listed in the Appendix. Detailed logic specifications are given in Section 4.0. The Appendix also contains copies of the current MPPI interlock test procedures for Setup and Patient Modes.

  14. National Synchrotron Light Source angiography personnel protection interlock

    SciTech Connect

    Gmuer, N.; Larson, R.; Thomlinson, W.

    1992-06-01

    This document has been written to describe the safety system operation at the NSLS X17B2 beamline Synchrotron Medical Research Facility (SMERF). The angiography exposure process involves scanning a patient up and down through dual fixed-position x-ray beams; exposure is controlled by opening and closing a fast-acting Safety Shutter mechanism at precise times in relation to the up and down motion of the scan chair. The fast-acting Safety Shutter mechanism is the primary radiation-stopping element protecting the patient while the chair is at rest and while it is reversing directions during the scan. Its fail-safe and fast operation is essential for the safety of the patient. Operation of X17B2 as a human subject angiography station necessitates the implementation of a personnel protection interlock system that, in conjunction with the Safety Shutters: permits safe access to the patient exposure area while the synchrotron radiation beam is illuminating the upstream dual energy monochromator; allows a patient to be imaged by the monochromatized beam under the supervision of a Responsible Physician, with scan chair motion and precision shutter actuation regulated by an angiography control computer, while providing a suitable number of safeguards against accidental radiation exposure; has different modes of operation to accommodate equipment set-up, test, and calibration; and patient exposure; and ensures the quick extinction of the beam if a potentially unsafe condition is detected. The interlock system which performs these safety functions is called the Angiography Personnel Protection Interlock (APPI). The APPI Document is organized such that the level of detail changes from a general overview to detailed engineering drawings of the hardware system.

  15. Photovoltaic module and interlocked stack of photovoltaic modules

    DOEpatents

    Wares, Brian S.

    2012-09-04

    One embodiment relates to an arrangement of photovoltaic modules configured for transportation. The arrangement includes a plurality of photovoltaic modules, each photovoltaic module including a frame having at least a top member and a bottom member. A plurality of alignment features are included on the top member of each frame, and a plurality of alignment features are included on the bottom member of each frame. Adjacent photovoltaic modules are interlocked by the alignment features on the top member of a lower module fitting together with the alignment features on the bottom member of an upper module. Other embodiments, features and aspects are also disclosed.

  16. Stable three-dimensional metallic carbon with interlocking hexagons.

    PubMed

    Zhang, Shunhong; Wang, Qian; Chen, Xiaoshuang; Jena, Puru

    2013-11-19

    Design and synthesis of 3D metallic carbon that is stable under ambient conditions has been a long-standing dream. We predict the existence of such phases, T6- and T14-carbon, consisting of interlocking hexagons. Their dynamic, mechanical, and thermal stabilities are confirmed by carrying out a variety of state-of-the-art theoretical calculations. Unlike the previously studied K4 and the simple cubic high pressure metallic phases, the structures predicted in this work are stable under ambient conditions. Equally important, they may be synthesized chemically by using benzene or polyacenes molecules. PMID:24191020

  17. Photovoltaic module and interlocked stack of photovoltaic modules

    DOEpatents

    Wares, Brian S.

    2014-09-02

    One embodiment relates to an arrangement of photovoltaic modules configured for transportation. The arrangement includes a plurality of photovoltaic modules, each photovoltaic module including a frame. A plurality of individual male alignment features and a plurality of individual female alignment features are included on each frame. Adjacent photovoltaic modules are interlocked by multiple individual male alignment features on a first module of the adjacent photovoltaic modules fitting into and being surrounded by corresponding individual female alignment features on a second module of the adjacent photovoltaic modules. Other embodiments, features and aspects are also disclosed.

  18. Dual load path ball screw with rod end swivel

    NASA Technical Reports Server (NTRS)

    Wngett, Paul (Inventor)

    2002-01-01

    A dual drive ball has a ball screw shaft coupled at one end to a gear train and coupled at the other end to a ball screw nut. The ball screw shaft and ball screw nut are connected through complementary helical grooves filled with ball bearing balls. The outer surface of the ball screw nut is plined and can be driven by a second gear train. An output tube is coupled at one end to the ball screw nut and at its opposite end has a connector portion with a groove on its inner surface. A rod end has a coupling member for coupling to a surface to be actuated and a shaft portion with a groobe on its outer surface. This shaft portion is received with in the outputtube portion and the corresponding grooves are coupled through the use of a plurality of ball bearing balls.

  19. 49 CFR 236.401 - Automatic block signal system and interlocking standards applicable to traffic control systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 false Automatic block signal system and interlocking standards applicable to traffic control systems. 236...Standards § 236.401 Automatic block signal system and interlocking standards applicable to traffic control systems....

  20. 49 CFR 236.401 - Automatic block signal system and interlocking standards applicable to traffic control systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 false Automatic block signal system and interlocking standards applicable to traffic control systems. 236...Standards § 236.401 Automatic block signal system and interlocking standards applicable to traffic control systems....

  1. 49 CFR 236.401 - Automatic block signal system and interlocking standards applicable to traffic control systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 false Automatic block signal system and interlocking standards applicable to traffic control systems. 236...Standards § 236.401 Automatic block signal system and interlocking standards applicable to traffic control systems....

  2. 49 CFR 236.401 - Automatic block signal system and interlocking standards applicable to traffic control systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 false Automatic block signal system and interlocking standards applicable to traffic control systems. 236...Standards § 236.401 Automatic block signal system and interlocking standards applicable to traffic control systems....

  3. 49 CFR 236.401 - Automatic block signal system and interlocking standards applicable to traffic control systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 false Automatic block signal system and interlocking standards applicable to traffic control systems. 236...Standards § 236.401 Automatic block signal system and interlocking standards applicable to traffic control systems....

  4. Post-traumatic malunion of the distal radial intra-articular fractures treated with autologous costal osteochondral grafts and bioabsorbable plates.

    PubMed

    Furukawa, Kayoko; Sakai, Akinori; Menuki, Kunitaka; Oshige, Toshihisa; Zenke, Yukichi; Nakamura, Toshitaka

    2014-03-01

    Intra-articular distal radial fractures with partial bone loss at the wrist were reconstructed using osteochondral grafts in 2 patients who were followed up for at least 18 months. Both patients experienced posttraumatic arthrosis of the wrist joint. The materials of the intra-articular fixation were bioabsorbable plates and screws. Reconstruction of a partially destroyed articular surface using a costal osteochondral graft is reliable and allows filling and resurfacing an articular cartilage void. PMID:24240625

  5. AUTOMATIC GENERATION AND VERIFICATION OF RAILWAY INTERLOCKING CONTROL TABLES USING FSM AND NUSMV

    Microsoft Academic Search

    Ahmad MIRABADI; Mohammad B. YAZDI

    2009-01-01

    Summary. Due to their important role in providing safe conditions for train movements, railway interlocking systems are considered as safety critical systems. The reliability, safety and integrity of these systems, relies on reliability and integrity of all stages in their lifecycle including the design, verification, manufacture, test, operation and maintenance. In this paper, the Automatic generation and verification of interlocking

  6. Automated Verification of Safety Properties in Railway Interlocking Systems Defined with

    E-print Network

    Setzer, Anton

    AVoCS 2008 Automated Verification of Safety Properties in Railway Interlocking Systems Defined the verification of safety conditions for the control of a railway interlocking system written in ladder logic is carried out. All translation steps have been implemented and tested for a real-world example of a railway

  7. Automated Verification of Safety Properties in Railway Interlocking Systems Defined with

    E-print Network

    Setzer, Anton

    AVoCS 2008 Automated Verification of Safety Properties in Railway Interlocking Systems Defined the verification of safety conditions for the control of a railway interlocking system written in ladder logic is carried out. All translation steps have been implemented and tested for a real­world example of a railway

  8. Asynchronous interlocked pipelined CMOS circuits operating at 3.3-4.5 GHz

    Microsoft Academic Search

    S. Schuster; W. Reohr; P. Cook; D. Heidel; M. Immediato; K. Jenkins

    2000-01-01

    Chip performance, power, noise, and clock synchronization are becoming formidable challenges as microprocessor performance moves into the GHz regime and beyond. Interlocked pipelined CMOS (IPCMOS), an asynchronous clocking technique, helps address these challenges. This paper shows how a typical block (e.g., Block D) is interlocked with all the blocks with which it interacts. In the forward direction, dedicated Valid signals

  9. Abstract: This paper considers an analysis of a domain of attraction within interlocked feedback model. First, we confirm that the interlocked feedback model expresses circadian rhythms. Next, we search a

    E-print Network

    E-1 Abstract: This paper considers an analysis of a domain of attraction within interlocked feedback model. First, we confirm that the interlocked feedback model expresses circadian rhythms. Next, weRNA and protain. Key Words: Systems Biology, Interlocked Feedback Model, Stability, Domain of Attraction 1

  10. Distal biceps and triceps ruptures.

    PubMed

    Kokkalis, Zinon T; Ballas, Efstathios G; Mavrogenis, Andreas F; Soucacos, Panayotis N

    2013-03-01

    Biceps and triceps tendon ruptures are rather uncommon injuries and are most commonly diagnosed clinically. Magnetic resonance imaging can help the clinician to differentiate an incomplete tear and define any degeneration of the tendon. Surgical anatomical repair is typically performed in acute complete ruptures whereas nonoperative treatment can be used for partial ruptures, as well as for patients unfit for surgery. Single incision techniques are associated with a higher rate of nerve injuries, while double incision repairs have a higher prevalence of heterotopic ossification. Although various fixation methods have been applied including bone tunnels, interference screws, suture anchors, cortical button fixation, the current evidence does not support the superiority of one method over the other. A well-planned postoperative rehabilitation programme is essential for a good final outcome. As better fixation devices are being used, more aggressive rehabilitation programmes have been applied. Epidemiology, clinical evaluation, diagnosis, surgical and conservative management of these injuries are presented in this review along with the authors' preferred technique for the anatomical repair of acute complete ruptures. PMID:23352149

  11. Revision cruciate ligament surgery with retention of femoral interference screws.

    PubMed

    Miller, M D

    1998-01-01

    As the popularity of cruciate ligament reconstruction continues to escalate, the need for revision surgery has also increased. Revision cruciate ligament surgery is often associated with difficult technical challenges including removing previously placed femoral interference screws. Not only can this hardware be difficult to remove, interference screw extraction often creates a large bony defect immediately adjacent to the revised femoral tunnel that can jeopardize the fixation of the new cruciate ligament graft. It is often possible to perform revision cruciate ligament reconstruction without removing femoral interference screws. This technical note provides several examples of this technique. Routine removal of femoral interference screws during revision cruciate ligament surgery is often not necessary. PMID:9486347

  12. Screws, Propellers and Fans Based on a Mobius Strip

    NASA Technical Reports Server (NTRS)

    Seiner, John M.; Backley, Floyd D.; Gilinsky, Mikhail

    1998-01-01

    A Mobius strip concept is intended for improving the working efficiency of propellers and screws. Applications involve cooling, boat propellers, mixing in appliance, blenders, and helicopters. Several Mobius shaped screws for the average size kitchen mixers have been made and tested. The tests have shown that the mixer with the Mobius shaped screw pair is most efficient, and saves more than 30% of the electric power by comparison with the standard. The created video film about these tests illustrates efficiency of Mobius shaped screws.

  13. Finite element analysis of osteosynthesis screw fixation in the bone stock: an appropriate method for automatic screw modelling.

    PubMed

    Wieding, Jan; Souffrant, Robert; Fritsche, Andreas; Mittelmeier, Wolfram; Bader, Rainer

    2012-01-01

    The use of finite element analysis (FEA) has grown to a more and more important method in the field of biomedical engineering and biomechanics. Although increased computational performance allows new ways to generate more complex biomechanical models, in the area of orthopaedic surgery, solid modelling of screws and drill holes represent a limitation of their use for individual cases and an increase of computational costs. To cope with these requirements, different methods for numerical screw modelling have therefore been investigated to improve its application diversity. Exemplarily, fixation was performed for stabilization of a large segmental femoral bone defect by an osteosynthesis plate. Three different numerical modelling techniques for implant fixation were used in this study, i.e. without screw modelling, screws as solid elements as well as screws as structural elements. The latter one offers the possibility to implement automatically generated screws with variable geometry on arbitrary FE models. Structural screws were parametrically generated by a Python script for the automatic generation in the FE-software Abaqus/CAE on both a tetrahedral and a hexahedral meshed femur. Accuracy of the FE models was confirmed by experimental testing using a composite femur with a segmental defect and an identical osteosynthesis plate for primary stabilisation with titanium screws. Both deflection of the femoral head and the gap alteration were measured with an optical measuring system with an accuracy of approximately 3 µm. For both screw modelling techniques a sufficient correlation of approximately 95% between numerical and experimental analysis was found. Furthermore, using structural elements for screw modelling the computational time could be reduced by 85% using hexahedral elements instead of tetrahedral elements for femur meshing. The automatically generated screw modelling offers a realistic simulation of the osteosynthesis fixation with screws in the adjacent bone stock and can be used for further investigations. PMID:22470474

  14. Robust microzip fastener: repeatable interlocking using polymeric rectangular parallelepiped arrays.

    PubMed

    Lee, Chanseok; Kim, Sang Moon; Kim, Young Joo; Choi, Yong Whan; Suh, Kahp-Yang; Pang, Changhyun; Choi, Mansoo

    2015-02-01

    We report a highly repeatable and robust microzip fastener based on the van der Waals force-assisted interlocking between rectangular parallelepiped arrays. To investigate zipperlike interlocking behaviors, various line arrays were fabricated with three different spacing ratios (1, 3, and 5 of 800 nm in width) and width of parallelepipeds (400 nm, 800 nm, and 5 ?m with the spacing ratio of 1). In addition, the different rigidity of line arrays was inspected for a repeatable microzip fastener. The normal and shear locking forces were measured with variation of the material rigidity as well as geometry of the array, in good agreement with a proposed theory based on the contact area and force balance. The maximum adhesion forces as high as ?8.5 N cm(-2) in the normal direction and ?29.6 N cm(-2) in the shear direction were obtained with high stability up to 1000 cycles. High stability of our fastening system was confirmed for preventing critical failures such as buckling and fracture in practical applications. PMID:25615547

  15. Biomechanical study of different plate configurations for distal humerus osteosynthesis.

    PubMed

    Bogataj, M; Kosel, F; Norris, R; Krkovic, M; Brojan, M

    2015-05-01

    Fractures of the distal humerus are most commonly fixed by open reduction and internal fixation, using plates and screws, either in a locking or in a non-locking construct. Three different plating systems are commonly used in practice. The most important differences between them are in plate orientation, which affects both the rigidity of the osteosynthesis and invasiveness of the surgical procedure. Unfortunately, there is no common agreement between surgeons about which plate configuration brings the best clinical outcome. In this study, we investigate the theoretical rigidity of plate osteosyntheses considering two types of AO/ASIF configurations (90° angle between plates), Mayo clinic (Acumed) configuration (180° between plates) and dorsal fixation of both plates. We also compared the results for cases with and without contact between the bone fragments. In the case of no bone contact, the Mayo clinic plate configuration is found to be the most rigid, followed by both AO/ASIF plate configurations, and the least rigid system is the Korosec plate configuration. On the other hand, no significant differences between all types of fixation configurations are found in cases with contact in-between the bone fragments. Our findings show that this contact is very important and can compensate for the lack of load carrying capacity of the implants. This could therefore incite other implant fixation solutions, leading to less invasive surgical procedures and consequently improved clinical outcome. PMID:25663513

  16. Percutaneous hemi-epiphysiodesis using transphyseal cannulated screws for genu valgum in adolescents

    PubMed Central

    Yamhure, Fernando Helo

    2009-01-01

    Purpose The purpose of this study was to assess percutaneous femoral distal hemi-epiphysiodesis using transphyseal cannulated screws in order to correct valgus angular deformities of the knee in pediatric and adolescent patients. Methods This is a prospective longitudinal study in which our experience with 52 patients is described. Results We evaluated 100 knees surgically managed for pathologic genu valgum over a 68-month period. The average age at surgery for boys and girls was 14 years and 7 months (range 12.7–15.1 years) and 13 years and 6 months (range 12.9–14.8 years), respectively. The pre-surgical tibiofemoral (T–F) angle was measured at between 14.17° and 35.3°, and the postoperative T–F was measured at between 6.2° and 15.8° (7.2° ± 0.65°, mean ± standard deviation), for an average correction of 0.73° ± 0.45° per month). The mean follow-up after surgery was 3.2 years (range 2.3–5.3 years). Conclusions We demonstrate a simple, fast and reproducible surgical technique for percutaneous epiphysiodesis with low morbidity, rapid rehabilitation and a rapid return to school and sports activities. We experienced no complications, such as overcorrection, undercorrection, postoperative hematoma or infection. We conclude that percutaneous screw epiphysiodesis is an excellent option for the treatment of genu valgum in adolescents. PMID:19756807

  17. Comparison of a New Braid Fixation System to an Interlocking Intramedullary Nail for Tibial Osteotomy Repair in an Ovine Model

    E-print Network

    Scharer, John E.

    Comparison of a New Braid Fixation System to an Interlocking Intramedullary Nail for Tibial) and polymethylmethacrylate bone cement with an interlocking intramedullary (IM) nail fixation in an ovine model. Study Design at 12 weeks after surgery compared with an interlocking IM nail repair. Clinical Relevance--A Nitinol

  18. CCCG 2010, Winnipeg MB, August 911, 2010 Any Monotone Boolean Function Can Be Realized by Interlocked Polygons

    E-print Network

    Demaine, Erik

    by Interlocked Polygons Erik D. Demaine Martin L. Demaine Ryuhei Uehara Abstract We show how to construct interlocked collections of sim- ple polygons in the plane that fall apart upon remov- ing certain combinations of pieces. Precisely, interior- disjoint simple planar polygons are interlocked if no subset can

  19. Synchronous Interlocked Pipelines Hans M. Jacobson Prabhakar N. Kudva Pradip Bose Peter W. Cook Stanley E. Schuster

    E-print Network

    Myers, Chris J.

    Synchronous Interlocked Pipelines Hans M. Jacobson Prabhakar N. Kudva Pradip Bose Peter W. Cook- ing critical stall signals. It has long been known that the interlocking properties of asynchronous interlock- ing. At the same time, there are considerable resources available in design tools and expertise

  20. Research in Political Sociology, Volume 17 (2008), pp. 3-42. THE INTERLOCK STRUCTURE OF THE POLICY-PLANNING

    E-print Network

    Rejaie, Reza

    2008-01-01

    Research in Political Sociology, Volume 17 (2008), pp. 3-42. THE INTERLOCK STRUCTURE OF THE POLICY-PLANNING NETWORK AND THE RIGHT TURN IN U.S. STATE POLICY Val Burris ABSTRACT This paper examines interlocks among to construct topographical maps of the pattern of interlocks among policy-planning groups and their change over

  1. Comptes Rendus des JNC 17 -Poitiers 2011 Suivi de l'endommagement en fatigue d'un composite renfort Interlock

    E-print Network

    Paris-Sud XI, Université de

    renfort Interlock Carbone/Epoxy par Emission Acoustique Fatigue damaging analysis of a carbon / epoxy 3D layer Interlock with Acoustic Emission Joseph Henry1, 2 , Zoheir Aboura1 , Kamel Khellil1 et Stéphane, cette technique est appliquée à des essais de fatigue sur un composite interlock. Dans un premier temps

  2. Transforaminal lumbar interbody fusion using unilateral pedicle screws and a translaminar screw.

    PubMed

    Sethi, Anil; Lee, Sandra; Vaidya, Rahul

    2009-03-01

    Lumbar spinal fusion is advancing with minimally invasive techniques, bone graft alternatives, and new implants. This has resulted in significant reductions of operative time, duration of hospitalization, and higher success in fusion rates. However, costs have increased as many new technologies are expensive. This study was carried out to investigate the clinical outcomes and fusion rates of a low implant load construct of unilateral pedicle screws and a translaminar screw in transforaminal lumbar interbody fusion (TLIF) which reduced the cost of the posterior implants by almost 50%. Nineteen consecutive patients who underwent single level TLIF with this construct were included in the study. Sixteen patients had a TLIF allograft interbody spacer placed, while in three a polyetheretherketone (PEEK) cage was used. Follow-up ranged from 15 to 54 months with a mean of 32 months. A clinical and radiographic evaluation was carried out preoperatively and at multiple time points following surgery. An overall improvement in Oswestry scores and visual analogue scales for leg and back pain (VAS) was observed. Three patients underwent revision surgery due to recurrence of back pain. All patients showed radiographic evidence of fusion from 9 to 26 months (mean 19) following surgery. This study suggests that unilateral pedicle screws and a contralateral translaminar screw are a cheaper and viable option for single level lumbar fusion. PMID:19015896

  3. Transforaminal lumbar interbody fusion using unilateral pedicle screws and a translaminar screw

    PubMed Central

    Lee, Sandra; Vaidya, Rahul

    2008-01-01

    Lumbar spinal fusion is advancing with minimally invasive techniques, bone graft alternatives, and new implants. This has resulted in significant reductions of operative time, duration of hospitalization, and higher success in fusion rates. However, costs have increased as many new technologies are expensive. This study was carried out to investigate the clinical outcomes and fusion rates of a low implant load construct of unilateral pedicle screws and a translaminar screw in transforaminal lumbar interbody fusion (TLIF) which reduced the cost of the posterior implants by almost 50%. Nineteen consecutive patients who underwent single level TLIF with this construct were included in the study. Sixteen patients had a TLIF allograft interbody spacer placed, while in three a polyetheretherketone (PEEK) cage was used. Follow-up ranged from 15 to 54 months with a mean of 32 months. A clinical and radiographic evaluation was carried out preoperatively and at multiple time points following surgery. An overall improvement in Oswestry scores and visual analogue scales for leg and back pain (VAS) was observed. Three patients underwent revision surgery due to recurrence of back pain. All patients showed radiographic evidence of fusion from 9 to 26 months (mean 19) following surgery. This study suggests that unilateral pedicle screws and a contralateral translaminar screw are a cheaper and viable option for single level lumbar fusion. PMID:19015896

  4. Wet Granulation in a Twin-Screw Extruder: Implications of Screw Design

    E-print Network

    Thompson, Michael

    granulation in twin-screw extrusion machinery is an attractive tech- nology for the continuous processing negative) reasons for adopting continuous processes in pharmaceutical produc- tion and pointed to extrusion known continuous tech- niques for granulation, a learning curve should be expected as more extrusion

  5. Acquired distal renal tubular acidosis in man

    Microsoft Academic Search

    O. S. Better

    1982-01-01

    Summary Distal renal tubular acidosis (dRTA) may complicate renal transplantation, liver cirrhosis, and obstructive uropathy. Indeed, its occurrence may be an early clue to an episode of rejection of the graft or to obstructive uropathy. The mechanism in most patients with dRTA is impaired distal secretion of protons. In some patients, however, back leak of protons from tubular lumen to

  6. Tibial Fixation of Bone-Patellar Tendon-Bone Grafts in Anterior Cruciate Ligament ReconstructionA Cadaveric Study of Bovine Bone Screw and Biodegradable Interference Screw

    Microsoft Academic Search

    Naiquan Zheng; Chad T. Price; Peter A. Indelicato; Bo Gao

    2008-01-01

    Background: The use of interference screw fixation for bone-patellar tendon-bone grafts in anterior cruciate ligament fixation is well established. No previous study has compared bovine bone screws and biodegradable interference screws or demonstrated their efficacy for requirements associated with early rehabilitation.Hypothesis: There is no difference in tension loss and pull-out strength between bovine bone screws and biodegradable interference screws.Study Design:

  7. Distal symphalangism: a report of two families.

    PubMed

    Poush, J R

    1991-01-01

    This study describes distal symphalangism in 36 individuals in two families, one of which is the largest pedigree of this rare defect yet documented. Distal symphalangism is ankylosis or rigidity of the distal interphalangeal joints of the hands and/or feet. The findings of this report substantiate the mutation as an autosomal dominant phenotype. Several manifestations of distal symphalangism were observed, including the lack of cutaneous creases over affected joints, brachydactyly, fourth-finger hypophalangism, absent nails, and rudimentary nails. Variability ranged from just toes affected, to a single finger affected, to all fingers and all lesser toes affected. The most common expression of the mutant gene was rigid index fingers. Craniosynostosis, premature closure of the sutures of the skull, was encountered twice in the larger of the two families. It is a possible pleiotropic effect of distal symphalangism. PMID:2061594

  8. Accuracy analysis of SCARA industrial robot based on screw theory

    Microsoft Academic Search

    Zhao Liang; Su Meng; Diao Changkun

    2011-01-01

    Based on an analysis of error sources of industrial robots, we build a pose error model of industrial robots with screw theory, which overcomes the defect that the error on the y-axis could not be reflected by the classical D-H parameter method. Given the error sources which influence the end- executor's accuracy, we established a screw representation of the static

  9. Study on the load distribution of ball screws with errors

    Microsoft Academic Search

    Xuesong Mei; Masaomi Tsutsumi; Tao Tao; Nuogang Sun

    2003-01-01

    A model is developed to analyze the load distribution of ball screws with geometry errors. The load distribution of the contact of the balls and grooves is theoretically investigated under various load conditions. The results demonstrate that the negative geometry errors of the ball screw result in the decrease of the load on balls or guiding grooves, and when the

  10. Robust compensation of elastic deformations in ball screw drives

    Microsoft Academic Search

    Amin Kamalzadeh; Daniel J. Gordon; Kaan Erkorkmaz

    2010-01-01

    Elastic deformations occur in ball screw drives typically due to inertial forces, guideway friction, and cutting forces. This results in elongation and compression of the ball screw, which deteriorates the dynamic linear positioning accuracy. Closing the control loop with a linear encoder helps to alleviate this problem to a certain extent. However, linear scales cost significantly more than rotary encoders

  11. FRICTION TORQUE AND EFFICIENCY IN BALL - SCREW SYSTEMS

    Microsoft Academic Search

    George V. Puiu; Dumitru N. Olaru; Vasile Puiu

    Complex relations for the friction torque and efficiency in a ball-screw system has been developed. The relations was adapted for a ball-screw system and influence of the speed and load on total friction torque were investigated. The efficiency of the system was computed and good agreement with the literature results was obtained. Also, a relation for the global friction coefficient

  12. Kinematic optimization of ball-screw transmission mechanisms

    Microsoft Academic Search

    D. Mundo; H. S. Yan

    2007-01-01

    The paper proposes a method for the kinematic optimization of transmission mechanisms, where non-circular (NC) gears are used to perform a mechanical control on the output motion. The investigation presented here deals with the motion control of a ball-screw transmission mechanism. The objective is lowering the peak acceleration value of the screw, by designing a pair of variable radius gears

  13. Correlation between feed velocity and preloading in ball screw drives

    Microsoft Academic Search

    A. Verl; S. Frey

    2010-01-01

    The efficiency and reliability of ball screw feed drives is a mayor issue concerning the productivity of modern machine tools. The preloading of a ball screw thereby determines the dynamical operational behavior as well as the attainable life span. The research results presented in this paper now clearly show that the value of pretension changes depending on the velocity of

  14. Compensation of Axial Vibrations in Ball Screw Drives

    Microsoft Academic Search

    A. Kamalzadeh; K. Erkorkmaz

    2007-01-01

    This paper presents a precision control strategy for ball screw drives. Axial vibrations are modeled and actively compensated in the control law, which enables the realization of high positioning bandwidth. Lead errors, arising from imperfections of the screw, are modeled and removed from the loop by offsetting their effect from the command trajectory and position feedback signals. Effectiveness of the

  15. Twin screw granulation - review of current progress.

    PubMed

    Thompson, M R

    2014-11-17

    Abstract Twin screw granulation (TSG) is a new process of interest to the pharmaceutical community that can continuously wet granulate powders, doing so at lower liquid concentrations and with better product consistency than found by a high shear batch mixer. A considerable body of research has evolved over the short time since this process was introduced but generally with little comparison of results. A certain degree of confidence has been developed through these studies related to how process variables and many attributes of machinery configuration will affect granulation but some major challenges still lay ahead related to scalability, variations in the processing regimes related to degree of channel fill and the impact of wetting and granulation of complex powder formulations. This review examines the current literature for wet granulation processes studied in twin screw extrusion machinery, summarizing the influences of operational and system parameters affecting granule properties as well as strives to provide some practical observations to newly interested users of the technique. PMID:25402966

  16. Effect of screw placement on fixation in the humeral head.

    PubMed

    Liew, A S; Johnson, J A; Patterson, S D; King, G J; Chess, D G

    2000-01-01

    The objectives of this study were (1) to determine the most advantageous screw locations within the humeral head when plate and screw fixation is to be used and (2) to determine the effect of positioning the screw tip abutting the subchondral bone. Ten paired humeral heads were harvested with a monoplanar cut through the anatomic neck. Through use of a standardized template, 7 holes were drilled and tapped in each specimen for insertion of 6.5-mm fully threaded cancellous screws perpendicular to the plane of the cut. Paired specimens were randomized into 2 groups, one with the screw purchase in central cancellous bone and the other with the screw purchase up to the subchondral bone. Each screw was pulled out axially at a displacement rate of 10 mm/min through use of a servohydraulic testing machine. The length of thread purchase, position within the head, and screw pullout load to failure were recorded. The normalized pullout force to failure was calculated by dividing absolute pullout force to failure by length of screw purchase. Data were analyzed by means of a 2-way repeated measures analysis of variance and post hoc Student-Newman-Keuls test. The central position had a significantly higher absolute pullout force to failure than all other sites (P < .05). By virtue of the humeral head shape, the central position also had a significantly greater length of screw purchase than all other positions (P < .05). The central position had a significantly higher relative pullout force to failure than all other positions (P < .05). Subchondral bone abutment positioning improved both the absolute and the relative pullout forces to failure (P < .05). When screws and plates are used in open reduction and internal fixation of a proximal humerus fracture, a major mode of failure is loss of fixation within the humeral head. On the basis of this study, optimal screw purchase with respect to bone fixation can be achieved by including screws located in the center of the humeral head in the subchondral abutment position. To minimize screw fixation failure, the anterosuperior position should be avoided. The pattern of distribution of the relative pullout force as measured in this study is consistent with previous observational studies of patterns of trabecular density within the humeral head. PMID:11075327

  17. The Analysis of Soil Resistance During Screw Displacement Pile Installation

    NASA Astrophysics Data System (ADS)

    Krasinski, Adam

    2015-02-01

    The application of screw displacement piles (SDP) is still increasing due to their high efficiency and many advantages. However, one technological problem is a serious disadvantage of those piles. It relates to the generation of very high soil resistance during screw auger penetration, especially when piles are installed in non-cohesive soils. In many situations this problem causes difficulties in creating piles of designed length and diameter. It is necessary to find a proper method for prediction of soil resistance during screw pile installation. The analysis of screw resistances based on model and field tests is presented in the paper. The investigations were carried out as part of research project, financed by the Polish Ministry of Science and Higher Education. As a result of tests and analyses the empirical method for prediction of rotation resistance (torque) during screw auger penetration in non-cohesive subsoil based on CPT is proposed.

  18. Biomechanical analysis of pedicle screw placement: a feasibility study.

    PubMed

    Wagnac, Eric; Michardière, Denis; Garo, Anaïs; Arnoux, Pierre-Jean; Mac-Thiong, Jean-Marc; Aubin, Carl-Eric

    2010-01-01

    In spinal instrumentation surgery, the optimal placement of pedicle screws that takes into account the cortical/cancellous bone quality, geometry and property distribution, and screw design is still undetermined despite several in vitro experiments. The objective of this study was to evaluate the feasibility of using a detailed finite element model (FEM) of an instrumented vertebra to simulate screw axial pull-out and to analyze the bone-screw mechanical interaction. The FEM was built using CT-scan images of the L3 vertebra (0.6mm thick contiguous slices) of a 50th percentile human male volunteer, in order to virtually implant a fully customizable pedicle screw in a straight-forward position. The 753,000 elements model takes into account local cortical bone thickness and integrates advanced material behavior (elasto-plastic) laws that simulate bone failure. Screw axial pull-out was simulated and compared to in vitro experimental data, and the stress distribution at the screw thread-bone interface was analyzed. The simulated screw pull-out force (non-linear response with a failure at 640N) was within the range of experimental data (500-660N). Von Mises stresses in the bony structures were concentrated around the root of each internal thread, with the maximum stress located near the first proximal thread, in the cortical bone of the posterior wall of the pars. This study shows the feasibility and relevance of using a detailed FEM to simulate screw pull-out and to analyze the bone-screw mechanical interaction. PMID:20543418

  19. A Surgical Method for Determining Proper Screw Length in ACDF

    PubMed Central

    Park, Hae-Gi; Kang, Moo-Sung; Kim, Kyung-Hyun; Park, Jeong-Yoon; Kim, Keun-Su

    2014-01-01

    Objective We describe a surgical tool that uses the distractor pin as a reference for determining proper screw length in ACDF. It is critical that screw purchase depth be as deep as possible without violating or penetrating the posterior cortical wall, which ensures strong pull out strength. Methods We enrolled 81 adult patients who underwent ACDF using an anterior cervical plate from 2010 to 2012. Patients were categorized into Groups A (42 patients: retractor pin used as a reference for screw length) and B (39 patients: control group). Intraoperative lateral x-rays were taken after screwing the retractor pin to confirm the approaching vertebral level. The ratio of retractor pin length to body anteroposterior (A-P) diameter was measured as a reference. Proper screw length was determined by comparison to the reference. Results The average distance from screw tip to posterior wall was 3.0±1.4mm in Group A and 4.1±2.3mm in Group B. The ratio of screw length to body sagittal diameter was 86.2±5.7% in Group A and 80.8±9.0% in Group B. Screw length to body sagittal diameter ratios higher than 4/5 occurred in 33 patients (90%) in Group A and 23 patients (59%) in Group B. No cases violated the posterior cortical wall. Conclusion We introduce a useful surgical method for determining proper screw length in ACDF using the ratio of retractor pin length to body A-P diameter as a reference. This method allows for deeper screw purchase depth without violation of the posterior cortical wall. PMID:25346756

  20. Complications associated with thoracic pedicle screws in spinal deformity

    PubMed Central

    Li, Gang; Lv, Guohua; Passias, Peter; Kozanek, Michal; Metkar, Umesh S.; Liu, Zhongjun; Wood, Kirkham B.; Rehak, Lubos

    2010-01-01

    Thoracic pedicle screws have superior anchoring strength compared with other available fixation techniques. However, these are not universally accepted in many developing countries because of the concerns regarding safety and complications. In addition, there is evidence that pedicle morphology is unique in Chinese patients. The goal of this study was to analyze the complications seen at our institution, while using thoracic pedicle screws for the treatment of thoracic deformity, and to determine the safety of our techniques for the treatment of thoracic deformity in a Chinese population. From 1998 to 2005, there were 208 thoracic deformity patients treated at our institution, 70 of whom were male and 138 were female. Their age ranged from 11 to 55 years (mean of 14.9 years). All of them underwent corrective deformity surgery using posterior pedicle screw systems and follow-up was available for at least 3 years. Etiologic diagnoses included adolescent idiopathic scoliosis in 119 patients, congenital kyphoscoliosis in 38, adult scoliosis in 37 and undetermined in 14. Screw positions were evaluated using intraoperative and postoperative radiographs and a CT scan was performed when a concern for screw malposition was present. All radiographic evaluations were carried out in a double-blinded fashion. A total of 1,123 thoracic pedicle screws were inserted (5.4 thoracic screws/patient). The deformity correction rate was 81, 65 and 62% for idiopathic, congenital and adult scoliosis patients, respectively. The overall complication rate was 16.5% at the final follow-up. Complication rates directly and indirectly related to pedicle screws were 7.2 and 9.3%, respectively. There were no significant screw-related neurologic or visceral complications that adversely affected long-term results. The complications seen with thoracic pedicle screws in a Chinese population were similar to other populations and could be utilized safely for the treatment of thoracic deformity in this population. PMID:20237943

  1. Biomechanical Performance of Variable and Fixed Angle Locked Volar Plates for the Dorsally Comminuted Distal Radius

    PubMed Central

    Martineau, D; Shorez, J; Beran, C; Dass, A G; Atkinson, P

    2014-01-01

    Background The ideal treatment strategy for the dorsally comminuted distal radius fracture continues to evolve. Newer plate designs allow for variable axis screw placement while maintaining the advantages of locked technology. The purpose of this study is to compare the biomechanical properties of one variable axis plate with two traditional locked constructs. Methods Simulated fractures were created via a distal 1 cm dorsal wedge osteotomy in radius bone analogs. The analogs were of low stiffness and rigidity to create a worst-case strength condition for the subject radius plates. This fracture-gap model was fixated using one of three different locked volar distal radius plates: a variable axis plate (Stryker VariAx) or fixed axis (DePuy DVR, Smith & Nephew Peri-Loc) designs. The constructs were then tested at physiologic loading levels in axial compression and bending (dorsal and volar) modes. Construct stiffness was assessed by fracture gap motion during the different loading conditions. As a within-study control, intact bone analogs were similarly tested. Results All plated constructs were significantly less stiff than the intact control bone models in all loading modes (p<0.040). Amongst the plated constructs, the VariAx was stiffest axially (p=0.032) and the Peri-Loc was stiffest in bending (p<0.024). Conclusion In this analog bone fracture gap model, the variable axis locking technology was stiffer in axial compression than other plates, though less stiff in bending. PMID:25328471

  2. Active interlock for the NSLS-II damping wiggler

    NASA Astrophysics Data System (ADS)

    Choi, J.; Willeke, F.

    2012-07-01

    The NSLS-II is a 3rd generation light source with ultra-low beam emittance that is currently under construction at the Brookhaven National Laboratory. Because the power of the synchrotron radiation from the damping wiggler (DW) is about 64 kW, a slight mis-steer can result in severe damage to the vacuum chamber. To avoid such problems, an active interlock system is being considered. The system dumps the beam when it departs from the predefined safe window in the phase space. In this paper, we present simple geometric arguments from which we define the safe window on the basis of betatron amplitudes. This window can be applied to any DW around the ring. For the entrance of the wiggler, we obtained window of ?x=±8.4 mm, ?x'=±429 ?rad and ?y=±2.1 mm, ?y'=±449 ?rad.

  3. We examine two pipeline structures which are employed in com-mercial microprocessors. The first is the load-use interlock (LUI)

    E-print Network

    Mudge, Trevor

    . The first is the load-use interlock (LUI) pipeline, which employs an interlock to ensure correct operation during load-use hazards. The second is the address-generation interlock (AGI) pipeline. It eliminates the load-use hazard, but has an address-generation hazard which requires an address-genera- tion interlock

  4. Real-Time Estimation of Ball-Screw Thermal Elongation Based upon Temperature Distribution of Ball-Screw

    Microsoft Academic Search

    Takehiko Kodera; Kazuhiro Yokoyama; Kazuo Miyaguchi; Yutaka Nagai; Takamasa Suzuki; Masami Masuda; Takanori Yazawa

    2004-01-01

    The optical telemeter system has been developed, which converts the temperature of rotating spindle to the digital data and carries the digital data from LED on the rotating side toward PD on the stationary side by the optical data transmission. Based upon the temperature distribution of hollow ball-screw obtained by the telemeter system, the thermal elongation of the ball-screw is

  5. A mechanism for the origin of screw dislocation sequences, giant screw dislocations, and polytypism in platelet crystals

    Microsoft Academic Search

    D. Kuhlmann-Wilsdorf; Dhananjai Pandey; P. Krishna

    1980-01-01

    Several workers have observed growth spirals of very large step heights on platelet crystals, sometimes associated with polytypism. These are attributed to spiral growth round a sequence of similar screw dislocations in a close planar array or a single giant screw dislocation. Polytypism can be (but is not necessarily) caused by such giant growth steps. The origin of the dislocations

  6. Lateral Movement of Screw Dislocations During Homoepitaxial Growth and Devices Yielded Therefrom Free of the Detrimental Effects of Screw Dislocations

    NASA Technical Reports Server (NTRS)

    Neudeck, Philip G. (Inventor); Powell, J. Anthony (Inventor)

    2004-01-01

    The present invention is related to a method that enables and improves wide bandgap homoepitaxial layers to be grown on axis single crystal substrates, particularly SiC. The lateral positions of the screw dislocations in epitaxial layers are predetermined instead of random, which allows devices to be reproducibly patterned to avoid performance degrading crystal defects normally created by screw dislocations.

  7. Implant augmentation: adding bone cement to improve the treatment of osteoporotic distal femur fractures: a biomechanical study using human cadaver bones.

    PubMed

    Wähnert, Dirk; Hofmann-Fliri, Ladina; Richards, R Geoff; Gueorguiev, Boyko; Raschke, Michael J; Windolf, Markus

    2014-11-01

    The increasing problems in the field of osteoporotic fracture fixation results in specialized implants as well as new operation methods, for example, implant augmentation with bone cement. The aim of this study was to determine the biomechanical impact of augmentation in the treatment of osteoporotic distal femur fractures.Seven pairs of osteoporotic fresh frozen distal femora were randomly assigned to either an augmented or nonaugmented group. In both groups, an Orthopaedic Trauma Association 33 A3 fractures was fixed using the locking compression plate distal femur and cannulated and perforated screws. In the augmented group, additionally, 1?mL of polymethylmethacrylate cement was injected through the screw. Prior to mechanical testing, bone mineral density (BMD) and local bone strength were determined. Mechanical testing was performed by cyclic axial loading (100?N to 750?N?+?0.05N/cycle) using a servo-hydraulic testing machine.As a result, the BMD as well as the axial stiffness did not significantly differ between the groups. The number of cycles to failure was significantly higher in the augmented group with the BMD as a significant covariate.In conclusion, cement augmentation can significantly improve implant anchorage in plating of osteoporotic distal femur fractures. PMID:25415673

  8. Unilateral Molar Distalization: A Nonextraction Therapy

    PubMed Central

    Prasad, M. Bhanu; Sreevalli, S.

    2012-01-01

    In the recent years, nonextraction treatment approaches and noncompliance therapies have become more popular in the correction of space discrepancies. One of the conventional approaches for space gaining in the arches without patient compliance is done by using certain extra oral appliances or intraoral appliance. The greatest advantage of certain appliances like fixed functional and molar distalization appliances is that they minimize the dependence on patient cooperation. Molar distalization appliances like pendulum appliance which distalizes the molar rapidly without the need of head gear can be used in patients as a unilateral space gaining procedure due to buccal segment crowding. PMID:23320203

  9. Perioperative management of distal pancreatectomy

    PubMed Central

    Fujino, Yasuhiro

    2015-01-01

    Recent advances in surgical techniques and perioperative management have markedly reduced operative morbidity after distal pancreatectomy (DP). However, some questions remain regarding the protocol for the perioperative management of DP, in particular, with regard to the development of pancreatic fistula (PF). A review of DP was therefore conducted in order to standardize the management of patients for a favorable outcome. Overall, operative technique and perioperative management emerged as two critical factors contributing to favorable outcome in DP patients. As for the operative method, surgical and closure techniques exhibited differences in outcome. Laparoscopic DP generally yields more favorable perioperative outcomes compared to open DP, and is applicable for benign tumors and some ductal carcinomas of the pancreas. Robotic DP is also available for safe pancreatic surgery. En bloc celiac axis resection offers a high R0 resection rate and potentially allows for some local control in the case of advanced pancreatic cancer. Following resection, staple closure was not found to reduce the rate of PF when compared to hand-sewn closure. In addition, ultrasonic dissection devices, fibrin glue sealing, and staple closure with mesh reinforcement were shown to significantly reduce PF, although there was some bias in these studies. In perioperative management, both preoperative and postoperative treatment affected outcome. First, preoperative endoscopic pancreatic stenting may be an effective prophylactic measure against fistula development following DP in selected patients. Second, in postoperative management, a multifactorial approach including prophylactic antibiotics improved high surgical site infection rates following complex hepato-pancreato-biliary surgery. Furthermore, although conflicting results have been reported, somatostatin analogues should be administered selectively to patients considered to have a high risk for PF. Finally, careful drain management also facilitates a favorable outcome in patients with PF after DP. The results of the review indicate that laparoscopic DP coupled with perioperative management influences outcome in DP patients. PMID:25805921

  10. Perioperative management of distal pancreatectomy.

    PubMed

    Fujino, Yasuhiro

    2015-03-21

    Recent advances in surgical techniques and perioperative management have markedly reduced operative morbidity after distal pancreatectomy (DP). However, some questions remain regarding the protocol for the perioperative management of DP, in particular, with regard to the development of pancreatic fistula (PF). A review of DP was therefore conducted in order to standardize the management of patients for a favorable outcome. Overall, operative technique and perioperative management emerged as two critical factors contributing to favorable outcome in DP patients. As for the operative method, surgical and closure techniques exhibited differences in outcome. Laparoscopic DP generally yields more favorable perioperative outcomes compared to open DP, and is applicable for benign tumors and some ductal carcinomas of the pancreas. Robotic DP is also available for safe pancreatic surgery. En bloc celiac axis resection offers a high R0 resection rate and potentially allows for some local control in the case of advanced pancreatic cancer. Following resection, staple closure was not found to reduce the rate of PF when compared to hand-sewn closure. In addition, ultrasonic dissection devices, fibrin glue sealing, and staple closure with mesh reinforcement were shown to significantly reduce PF, although there was some bias in these studies. In perioperative management, both preoperative and postoperative treatment affected outcome. First, preoperative endoscopic pancreatic stenting may be an effective prophylactic measure against fistula development following DP in selected patients. Second, in postoperative management, a multifactorial approach including prophylactic antibiotics improved high surgical site infection rates following complex hepato-pancreato-biliary surgery. Furthermore, although conflicting results have been reported, somatostatin analogues should be administered selectively to patients considered to have a high risk for PF. Finally, careful drain management also facilitates a favorable outcome in patients with PF after DP. The results of the review indicate that laparoscopic DP coupled with perioperative management influences outcome in DP patients. PMID:25805921

  11. Semiconstrained Distal Radioulnar Joint Prosthesis

    PubMed Central

    Savvidou, Christiana; Murphy, Erin; Mailhot, Emilie; Jacob, Shushan; Scheker, Luis R.

    2013-01-01

    Distal radioulnar joint (DRUJ) problems can occur as a result of joint instability, abutment, or incongruity. The DRUJ is a weight-bearing joint; the ulnar head is frequently excised either totally or partially, and in some cases it is fused, because of degenerative, rheumatoid, or posttraumatic arthritis. Articles about these procedures report the ability to pronate and supinate, but they rarely discuss grip strength, and even less do they address lifting capacity. We report the long term results of the first 35 patients who underwent total DRUJ arthroplasty with the Aptis DRUJ prosthesis after 5 years follow-up. Surgical indications were all causes of dysfunctional DRUJ (degenerative, posttraumatic, autoimmune, congenital). We recorded data for patient demographics, range of motion (ROM), strength, and lifting capacity of the operated and of the nonoperated extremity. Pain and functional assessments were also recorded. The Aptis DRUJ prosthesis, a bipolar self-stabilizing DRUJ endoprosthesis that restores forearm function, consists of a semiconstained and modular implant designed to replace the function of the ulnar head, the sigmoid notch of the radius, and the triangular fibrocartilage ligaments. The surgical technique is presented in detail. The majority of the patients regained adequate ROM and improved their strength and lifting capacity to the operated side. Pain and activities of daily living were improved. Twelve patients experienced complications, most commonly being extensor carpi ulnaris (ECU) tendinitis, ectopic bone formation, bone resorption with stem loosening, low-grade infection, and need for ball replacement. The Aptis total DRUJ replacement prosthesis is an alternative to salvage procedures that enables a full range of motion as well as the ability to grip and lift weights encountered in daily living activities. PMID:24436788

  12. SCREW COMPRESSOR CHARACTERISTICS FOR HELIUM REFRIGERATION SYSTEMS

    SciTech Connect

    Ganni, Venkatarao; Knudsen, Peter; Creel, Jonathan; Arenius, Dana; Casagrande, Fabio; Howell, Matt

    2008-03-01

    The oil injected screw compressors have practically replaced all other types of compressors in modern helium refrigeration systems due to their large displacement capacity, minimal vibration, reliability and capability of handling helium's high heat of compression.At the present state of compressor system designs for helium systems, typically two-thirds of the lost input power is due to the compression system. Therefore it is important to understand the isothermal and volumetric efficiencies of these machines to help properly design these compression systems to match the refrigeration process. This presentation summarizes separate tests that have been conducted on Sullair compressors at the Superconducting Super-Collider Laboratory (SSCL) in 1993, Howden compressors at Jefferson Lab (JLab) in 2006 and Howden compressors at the Spallation Neutron Source (SNS) in 2006. This work is part of an ongoing study at JLab to understand the theoretical basis for these efficiencies and their loss

  13. Spline-Screw Payload-Fastening System

    NASA Technical Reports Server (NTRS)

    Vranish, John M.

    1994-01-01

    Payload handed off securely between robot and vehicle or structure. Spline-screw payload-fastening system includes mating female and male connector mechanisms. Clockwise (or counter-clockwise) rotation of splined male driver on robotic end effector causes connection between robot and payload to tighten (or loosen) and simultaneously causes connection between payload and structure to loosen (or tighten). Includes mechanisms like those described in "Tool-Changing Mechanism for Robot" (GSC-13435) and "Self-Aligning Mechanical and Electrical Coupling" (GSC-13430). Designed for use in outer space, also useful on Earth in applications needed for secure handling and secure mounting of equipment modules during storage, transport, and/or operation. Particularly useful in machine or robotic applications.

  14. Spline-Locking Screw Fastening Strategy (SLSFS)

    NASA Technical Reports Server (NTRS)

    Vranish, John M.

    1991-01-01

    A fastener was developed by NASA Goddard for efficiently performing assembly, maintenance, and equipment replacement functions in space using either robotic or astronaut means. This fastener, the 'Spline Locking Screw' (SLS) would also have significant commercial value in advanced manufacturing. Commercial (or DoD) products could be manufactured in such a way that their prime subassemblies would be assembled using SLS fasteners. This would permit machines and robots to disconnect and replace these modules/parts with ease, greatly reducing life cycle costs of the products and greatly enhancing the quality, timeliness, and consistency of repairs, upgrades, and remanufacturing. The operation of the basic SLS fastener is detailed, including hardware and test results. Its extension into a comprehensive fastening strategy for NASA use in space is also outlined. Following this, the discussion turns toward potential commercial and government applications and the potential market significance of same.

  15. Spline-locking screw fastening strategy

    NASA Technical Reports Server (NTRS)

    Vranish, John M.

    1992-01-01

    A fastener was developed by NASA Goddard for efficiently performing assembly, maintenance, and equipment replacement functions in space using either robotics or astronaut means. This fastener, the 'Spline Locking Screw' (SLS) would also have significant commercial value in advanced space manufacturing. Commercial (or DoD) products could be manufactured in such a way that their prime subassemblies would be assembled using SLS fasteners. This would permit machines and robots to disconnect and replace these modules/parts with ease, greatly reducing life cycle costs of the products and greatly enhancing the quality, timeliness, and consistency of repairs, upgrades, and remanufacturing. The operation of the basic SLS fastener is detailed, including hardware and test results. Its extension into a comprehensive fastening strategy for NASA use in space is also outlined. Following this, the discussion turns toward potential commercial and government applications and the potential market significance of same.

  16. Salvaging the Pullout Strength of Stripped Screws in Osteoporotic Bone

    PubMed Central

    Pechon, Pierre H. M.; Mears, Simon C.; Langdale, Evan R.; Belkoff, Stephen M.

    2013-01-01

    Our goal was to determine whether the pullout strength of stripped screw holes in osteoporotic bone could be increased with readily available materials from the operating room. We inserted 3.5-mm stainless steel nonlocking self-tapping cortical screws bicortically into 5 osteoporotic humeri. Each screw was first stripped by rotating it 1 full turn past maximum torque. In the control group, the screw was pulled out using an MTS machine (858; MTS Inc, Eden Prairie, Minnesota). In the treatment groups, the screw was removed, the hole was augmented with 1 of the 3 materials (stainless steel wire, polysorb suture, or polyethylene terephthalate glycol plastic sheet), and the screws were replaced and then pulled out. The effect of material on pullout strength was checked for significance (P < .05) using a general linearized latent and mixed model (Stata10; StataCorp, College Station, Texas). The mean (95% confidence interval) pullout strength for the unaugmented hole was 138 N (range 88-189), whereas the holes augmented with plastic, suture, or wire had mean pullout strengths of 255 N (range 177-333), 228 N (range 149-308), and 396 N (range 244-548), respectively. Although wire augmentation resulted in pullout strength that was significantly greater than that of the unaugmented screw, it was still below that of the intact construct. PMID:24093076

  17. Management of a fractured implant abutment screw: a clinical report.

    PubMed

    Canpolat, Ceyhun; Ozkurt-Kayahan, Zeynep; Kazazo?lu, Ender

    2014-07-01

    In an abutment screw fracture, it is generally a challenge for the clinician to remove fractured fragments. In some cases, the screw cannot be removed, and alternative solutions should be considered. This clinical report describes the replacement of a ball attachment with a fractured screw, which was impossible to retrieve, with a cast dowel with ball attachment. The patient who presented to the Department of Prosthodontics, Yeditepe University, Faculty of Dentistry was a 65-year-old woman, wearing a mandibular complete denture supported by two implants for 4 years. She complained about the loss of retention of the denture because of the fractured abutment screw, and it was found that another dentist had previously tried to retrieve the fractured screw with no success. It was decided to construct a cast dowel with ball attachment to improve retention without sacrificing the implant. The interior of the implant and the fractured screw were machined with a rotating instrument. An impression was taken with a metal strip and silicone-based materials. In the laboratory, a stone die was generated from the impression, and a custom-made cast dowel with ball attachment was constructed. It was then cemented with glass ionomer cement and connected to the denture with the direct method. The alternative procedure described in this clinical report was successful for the removal of the fractured abutment screw and use of the existing denture. PMID:24393481

  18. Midline lumbar fusion with cortical bone trajectory screw.

    PubMed

    Mizuno, Masaki; Kuraishi, Keita; Umeda, Yasuyuki; Sano, Takanori; Tsuji, Masanori; Suzuki, Hidenori

    2014-01-01

    A novel cortical bone trajectory (CBT) screw technique provides an alternative fixation technique for lumbar spine. Trajectory of CBT screw creates a caudo-cephalad path in sagittal plane and a medio-lateral path in axial plane, and engages cortical bone in the pedicle. The theoretical advantage is that it provides enhanced screw grip and interface strength. Midline lumbar fusion (MIDLF) is composed of posterior midline approach, microsurgical laminectomy, and CBT screw fixation. We adopted the MIDLF technique for lumbar spondylolisthesis. Advantages of this technique include that decompression and fusion are available in the same field, and it minimizes approach-related damages. To determine whether MIDLF with CBT screw is as effective as traditional approach and it is minimum invasive technique, we studied the clinical and radiological outcomes of MIDLF. Our results indicate that MIDLF is effective and minimum invasive technique. Evidence of effectiveness of MIDLF is that patients had good recovery score, and that CBT screw technique was safety in clinical and stable in radiological. MIDLF with CBT screw provides the surgeon with additional options for fixation. This technique is most likely to be useful for treating lumbar spondylolisthesis in combination with midline decompression and insertion of an interbody graft, such as the transforaminal lumbar interbody fusion or posterior lumbar interbody fusion techniques. PMID:25169139

  19. Comparison of Expansive Pedicle Screw and Polymethylmethacrylate-Augmented Pedicle Screw in Osteoporotic Sheep Lumbar Vertebrae: Biomechanical and Interfacial Evaluations

    PubMed Central

    Zhang, Bo; Xie, Qing-yun; Wang, Cai-ru; Liu, Jin-biao; Liao, Dong-fa; Jiang, Kai; Lei, Wei; Pan, Xian-ming

    2013-01-01

    Background It was reported that expansive pedicle screw (EPS) and polymethylmethacrylate-augmented pedicle screw (PMMA-PS) could be used to increase screw stability in osteoporosis. However, there are no studies comparing the two kinds of screws in vivo. Thus, we aimed to compare biomechanical and interfacial performances of EPS and PMMA-PS in osteoporotic sheep spine. Methodology/Principal Findings After successful induction of osteoporotic sheep, lumbar vertebrae in each sheep were randomly divided into three groups. The conventional pedicle screw (CPS) was inserted directly into vertebrae in CPS group; PMMA was injected prior to insertion of CPS in PMMA-PS group; and the EPS was inserted in EPS group. Sheep were killed and biomechanical tests, micro-CT analysis and histological observation were performed at both 6 and 12 weeks post-operation. At 6-week and 12-week, screw stabilities in EPS and PMMA-PS groups were significantly higher than that in CPS group, but there were no significant differences between EPS and PMMA-PS groups at two study periods. The screw stability in EPS group at 12-week was significantly higher than that at 6-week. The bone trabeculae around the expanding anterior part of EPS were more and denser than that in CPS group at 6-week and 12-week. PMMA was found without any degradation and absorption forming non-biological “screw-PMMA-bone” interface in PMMA-PS group, however, more and more bone trabeculae surrounded anterior part of EPS improving local bone quality and formed biological “screw-bone” interface. Conclusions/Significance EPS can markedly enhance screw stability with a similar effect to the traditional method of screw augmentation with PMMA in initial surgery in osteoporosis. EPS can form better biological interface between screw and bone than PMMA-PS. In addition, EPS have no risk of thermal injury, leakage and compression caused by PMMA. We propose EPS has a great application potential in augmentation of screw stability in osteoporosis in clinic. PMID:24086381

  20. Use of fluoroscopy to evaluate iliac screw position.

    PubMed

    Orchowski, Joseph R; Polly, David W; Kuklo, Timothy R; Klemme, William R; Schroeder, Teresa M

    2006-03-01

    Iliac screw fixation is often used for long fusions to the sacropelvis. Maximum iliac screw purchase is obtained both by placing the screws within 1.5 cm of the greater sciatic notch and by extending them anterior to the axis of rotation in flexion-extension. Screw insertion is "blinded" or dependent on tactile feedback, and hence extreme care is necessary to avoid incorrect placement and damage to vital neurovascular structures in the pelvis and sciatic notch. Long screws may violate the hip joint while medial placement may injure the lumbosacral plexus and the nearby vessels. To explore the best intraoperative fluoroscopic method of determining optimal iliac screw placement, we used a synthetic pelvis model to investigate screw placement conditions: (1) optimal anatomic placement, (2) violation of the sciatic notch, (3) hip joint violation, (4) medial wall violation, and (5) lateral wall violation. Each condition was examined utilizing fluoroscopy with posteroanterior, inlet, outlet, lateral, iliac oblique, and obturator oblique Judet views to simulate operative conditions. These views were obtained to evaluate critical malposition of iliac screws. We found that, for a sciatic notch violation, the obturator oblique view best demonstrated the cortical breech, while for a hip joint violation, the inlet and outlet views were best. For a medial wall violation, the iliac oblique view best showed the violation. For a lateral wall violation, we were unable to demonstrate the cortical breech using these fluoroscopic views. Fluoroscopy is an effective method to determine sciatic notch, hip joint, and medial wall violations after iliac screw placement; however, it is not effective in identifying a lateral wall violation. PMID:16610381

  1. 49 CFR 571.102 - Standard No. 102; Transmission shift position sequence, starter interlock, and transmission...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...sequence, starter interlock, and transmission braking effect. S1. Purpose...specifies the requirements for the transmission shift position sequence...and for a braking effect of automatic transmissions, to reduce the...

  2. Stock fluctuations are correlated and amplified across networks of interlocking directorates

    E-print Network

    Saavedra, Serguei; Rohr, Rudolf P; Schnabel, Michael; Uzzi, Brian; Bascompte, Jordi

    2014-01-01

    Traded corporations are required by law to have a majority of outside directors on their board. This requirement allows the existence of directors who sit on the board of two or more corporations at the same time, generating what is commonly known as interlocking directorates. While research has shown that networks of interlocking directorates facilitate the transmission of information between corporations, little is known about the extent to which such interlocking networks can explain the fluctuations of stock price returns. Yet, this is a special concern since the risk of amplifying stock fluctuations is latent. To answer this question, here we analyze the board composition, traders' perception, and stock performance of more than 1500 US traded corporations from 2007-2011. First, we find that the fewer degrees of separation between two corporations in the interlocking network, the stronger the temporal correlation between their stock price returns. Second, we find that the centrality of traded corporations...

  3. 46 CFR 111.70-7 - Remote control, interlock, and indicator circuits.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Motor Circuits, Controllers...control, interlock, or indicator circuit, all practicable steps must be taken to eliminate all but one source of power...

  4. Interlock recovery during the drying, calcination and vitrification phase of Am/Cm processing

    SciTech Connect

    Snyder, T.K.

    2000-01-20

    This document summarizes the results of five CIM5 [5-inch Cylindrical Induction Melter] runs designed to demonstrate power interlock recovery methods during the drying, calcination and vitrification phases of the Am/Cm melter cycle.

  5. Genetics Home Reference: Distal arthrogryposis type 1

    MedlinePLUS

    ... angled outward toward the fifth finger (ulnar deviation). Clubfoot, which is an inward- and upward-turning foot, ... providers. American Academy of Orthopedic Surgeons: Treatment for Clubfoot Genetic Testing Registry: Arthrogryposis multiplex congenita distal type ...

  6. Tightening force and torque of nonlocking screws in a reverse shoulder prosthesis A. Terrier a,

    E-print Network

    Guerraoui, Rachid

    Tightening force and torque of nonlocking screws in a reverse shoulder prosthesis A. Terrier a, , S Arthroplasty Reversed prosthesis Screw Cadaveric study Background: Reversed shoulder arthroplasty and screwing angle, of the nonlocking screws of the Aquealis reversed prosthesis. In addition, the amount

  7. The Development of using the digital projection method to measure the contact angle of ball screw

    Microsoft Academic Search

    Chun-Jen Chen; Wenyuh Jywe; Yu-Chun Liu; Hsin-Hong Jwo

    2011-01-01

    The ball screw frequently used to drive or translate the parts on the precision machine, such as machine tool and motorized stage. Therefore they were most frequently used on the precision machine, semiconductor equipment, medical instrument and aero industry. The main parts of ball screw are screw, ball and nut. The contact angle between the screw, ball and nut will

  8. Moving follower rest design using vibration absorbers for ball screw grinding

    Microsoft Academic Search

    C. C. Cheng; C. P. Kuo; F. C. Wang; W. N. Cheng

    2009-01-01

    A novel design of follower rest used in ball screw grinding machine is proposed. Installed on the grinding wheel holder and moving along the ball screw, the follower rest is designed to be a vibration absorber with its driving point attached on the ball screw close to the grinding zone. It is used not only to suppress the ball screw

  9. 2D-fluoroscopic navigated percutaneous screw fixation of pelvic ring injuries - a case series

    Microsoft Academic Search

    Florian Gras; Ivan Marintschev; Arne Wilharm; Kajetan Klos; Thomas Mückley; Gunther O Hofmann

    2010-01-01

    BACKGROUND: Screw fixation of pelvic ring fractures is a common, but demanding procedure and navigation techniques were introduced to increase the precision of screw placement. The purpose of this case series was the evaluation of screw misplacement rate and functional outcome of percutaneous screw fixation of pelvic ring disruptions using a 2D navigation system. METHODS: Between August 2004 and December

  10. Analysis of Material Flow in Screw Extrusion of Aluminum

    SciTech Connect

    Haugen, Bjoern; Oernskar, Magnus; Welo, Torgeir; Wideroee, Fredrik [Department of Engineering Design and Materials, NTNU (Norway)

    2010-06-15

    Screw extrusion of aluminum is a new process for production of aluminum profiles. The commercial potential could be large. Little experimental and numerical work has been done with respect to this process.The material flow of hot aluminum in a screw extruder has been analyzed using finite element formulations for the non-Newtonian Navier-Stokes equations. Aluminum material properties are modeled using the Zener-Holloman material model. Effects of stick-slip conditions are investigated with respect to pressure build up and mixing quality of the extrusion process.The numerical results are compared with physical experiments using an experimental screw extruder.

  11. Intersection of screw dislocations in fcc crystals during torsional deformation

    NASA Astrophysics Data System (ADS)

    Myshlyaev, M. M.

    2012-03-01

    Dislocation reactions, including dislocation intersections during various processes in crystals, play an important and often crucial role. This is most pronounced during plastic deformation of crystalline solids, which attracts particular interest from researchers. Intersection of screw dislocations in fcc crystals during their deformation by uniaxial tension and compression was studied by A. Cottrell [1]. It was shown that the intersection of similar screw dislocations moving toward each other results in the formation of interstitial thresholds on them; in the case of intersection of opposite screw dislocations, vacancy thresholds are formed on them.

  12. A BIOMECHANICAL ANALYSIS OF A NEW INTERLOCK SUTURE TECHNIQUE FOR FLEXOR TENDON REPAIR

    Microsoft Academic Search

    G. A. ROBERTSON; M. M. AL-QATTAN

    1992-01-01

    Using a computerised tensometer, both the gap-producing and breaking forces of a new interlocking suture for flexor tendon repair were compared to the modified Kessler and the Strickland techniques. 30 porcine deep flexor tendons were used in each group and all repairs were performed with 3\\/0 polypropylene sutures. The interlock technique withstood gap-producing and breaking forces significantly better than the

  13. Flexor tendon repair after rupture caused by volar plate fixation of the distal radius.

    PubMed

    Rubensson, Carin C; Ydreborg, Karin; Boren, Linda; Karlander, Lars-Erik

    2015-04-01

    Volar plate fixation of unstable fractures of the distal radius is preferred by a majority of surgeons today. One known complication is the rupture of flexor tendons. The aim of this paper is to present flexor tendon ruptures after volar plate fixation analysing the clinical outcome after tendon surgery, aetiology, and methods of prevention. Seventeen consecutive ruptures in 14 patients were included. The incidence was 1.4%. Three patients declined tendon surgery. Eleven patients were treated with a free tendon graft. Only two patients showed excellent results regarding mobility in the thumb and/or fingers. Analysis of radiographs demonstrated sub-optimal placement of plate or screws in all cases. Rupture of a flexor tendon is a serious complication where the functional outcome after surgical reconstruction is uncertain. Early removal of the plate when the placement is sub-optimal or when local volar tenderness appears would probably prevent many ruptures. PMID:25162925

  14. 21 CFR 888.3070 - Pedicle screw spinal system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3070 Pedicle screw spinal system. ...22Cr-13Ni-5Mn stainless steel, Ti-6Al-4V, and unalloyed titanium, that allow the surgeon to build an implant...

  15. 21 CFR 888.3070 - Pedicle screw spinal system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3070 Pedicle screw spinal system. ...22Cr-13Ni-5Mn stainless steel, Ti-6Al-4V, and unalloyed titanium, that allow the surgeon to build an implant...

  16. 21 CFR 888.3070 - Pedicle screw spinal system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3070 Pedicle screw spinal system. ...22Cr-13Ni-5Mn stainless steel, Ti-6Al-4V, and unalloyed titanium, that allow the surgeon to build an implant...

  17. 21 CFR 888.3070 - Pedicle screw spinal system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3070 Pedicle screw spinal system. ...22Cr-13Ni-5Mn stainless steel, Ti-6Al-4V, and unalloyed titanium, that allow the surgeon to build an implant...

  18. Wet-gas compression in twin-screw multiphase pumps

    E-print Network

    Chan, Evan

    2009-05-15

    Multiphase pumping with twin-screw pumps is a relatively new technology that has been proven successful in a variety of field applications. By using these pumps to add energy to the combined gas and liquid wellstream with minimal separation...

  19. 21. NBS SUIT LAB. THREE GLOVES, HELMET, AND SCREW DRIVER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    21. NBS SUIT LAB. THREE GLOVES, HELMET, AND SCREW DRIVER TORQUE WRENCH FOR ASSEMBLY AND REPAIR OF BOTH. - Marshall Space Flight Center, Neutral Buoyancy Simulator Facility, Rideout Road, Huntsville, Madison County, AL

  20. Crystal geometry of screw dislocation glide in tungsten nanocrystals

    NASA Astrophysics Data System (ADS)

    Sadanov, E. V.

    2015-02-01

    A zigzag pattern of low-temperature dislocation glide occurring in tungsten nanocrystals in the intersecting planes {110} and {211}, which belong to the <111> crystallographic zone, has been revealed using field ion microscopy. It has been shown that cores of 1/2[111] screw dislocations are undissociated within the limits of the resolution of the field ion microscope. It has been found experimentally that surface atoms are displaced into metastable positions in the region of the trace of screw dislocation motion.

  1. Modeling and positioning control of a ball screw driven stage

    Microsoft Academic Search

    M. J. Jang; K. C. Lin; C. L. Chen

    2004-01-01

    The demand for high precision stages has received great attention due to the progress of nanotechnology. In the ball-screw-driven systems, the friction behavior dominates the resulting performance and is usually known as the stick-slip phenomenon. In this paper, friction models are introduced to describe the dynamic behavior of a conventional ball-screw-driven x-y stage. Two sets of controllers corresponding to the

  2. Metatarsal Osteotomy Using Double-Threaded Screws - Biomechanical Analysis

    Microsoft Academic Search

    Anna Ziebowicz; Anita Kajzer; Wojciech Kajzer; Jan Marciniak

    \\u000a The fundamental purpose of this research was to determine the biomechanical characteristics of the first metatarsal bone -\\u000a double-threaded screws system made of stainless steel (Cr-Ni-Mo) and an assessment of its stability. To define the biomechanical\\u000a characteristics of the system, the finite element method and experimental method were applied. Geometric models of metatarsal\\u000a bone and double-threaded screws, were discretized by

  3. On giant screw dislocations in ZnS polytype crystals

    Microsoft Academic Search

    S. Mardix; A. R. Lang; I. Blech

    1971-01-01

    Vapour-grown platelet crystals of ZnS containing long-period polytypes have been found by x-ray topography to contain a single screw dislocation with a very large Burgers vector parallel to the c axis. Individual polytype regions can have highly perfect lattices; the few dislocations observed in them in addition to the giant screw have Burgers vectors in the basal plane. A divergent-beam

  4. Modeling and control of a twin-screw extruder

    E-print Network

    Richburg, Leslie Leitzy

    1989-01-01

    MODELING AND CONTROL OF A TWIN-SCREW EXTRUDER A Thesis LESLIE LEITZY RICHBHRG Submitted to the Office of Graduate Studies of Texas ARM TJniversitl in partial fulfillment of the requirements for the degree of MASTER OF SCIE'FACE December 1989... Major Subject: Agricultural Engineering MODELING AND CONTROL OF A TWIN-SCREW EXTRUDER A Thesis by LESLIE LEITZY RICHBURG A. Dale Whittaker (Chair of Committee) Donald A. Bender (Member) Don R. Bittner (Member) . R. Hocking Larry . Wisdom...

  5. Residence time distribution in a corotating twin-screw extruder

    Microsoft Academic Search

    J. P Puaux; G Bozga; A Ainser

    2000-01-01

    A modeling study for the polymer flow and mixing in a corotating twin-screw extruder is presented. The residence time distribution (RTD) in a fully intermeshing corotating twin-screw extruder was measured, using iron powder as tracer, and an LDPE as flow material. Pulse-type input signal experiments were performed in different working conditions. To fit the experimental data obtained on two different

  6. Development of intraosseous infusion of the distal phalanx to access the foot lamellar circulation in the standing, conscious horse.

    PubMed

    Nourian, Ali R; Mills, Paul C; Pollitt, Christopher C

    2010-03-01

    Intraosseous (i.o.) infusion of the distal phalanx (IOIDP) as a delivery route targeting hoof lamellar tissue of standing, conscious horses was evaluated. Following sedation and regional nerve blockade in six Standardbred horses, a microdialysis (MD) probe was implanted into the hoof lamellar tissue of one forelimb. A purpose designed cannulated bone screw was introduced into the body of the distal phalanx, approximately 6 cm from the MD probe. Gentamicin solution (25 mg/mL) was infused at 20 microL/min through the bone screw for 2 h without the application of a tourniquet. MD and blood samples were collected at regular intervals and analysed for gentamicin concentrations. Gentamicin was present in lamellar tissue at much higher concentrations than peripheral serum. The mean concentration of gentamicin was 24.4, 20.5 and 4.4 microg/mL in extracellular fluid (ECF) and 0.28, 0.5 and 0.32 microg/mL in serum samples collected 60, 120 and 150 min after IOIDP was started, respectively. A clinically safe and efficacious i.o. drug delivery to the hoof lamellar tissue of standing, conscious horse was developed. PMID:19540781

  7. Archaic and modern human distal humeral morphology.

    PubMed

    Yokley, Todd R; Churchill, Steven E

    2006-12-01

    The morphology of the proximal ulna has been shown to effectively differentiate archaic or premodern humans (such as Homo heidelbergensis and H. neanderthalensis) from modern humans (H. sapiens). Accordingly, the morphology of adjacent, articulating elements should be able to distinguish these two broad groups as well. Here we test the taxonomic utility of another portion of the elbow, the distal humerus, as a discriminator of archaic and modern humans. Principal components analysis was employed on a suite of log-raw and log-shape distal humeral measures to examine differences between Neandertal and modern human distal humeri. In addition, the morphological affinities of Broken Hill (Kabwe) E.898, an archaic human distal humeral fragment from the middle Pleistocene of Zambia, and five Pliocene and early Pleistocene australopith humeri were assessed. The morphometric analyses effectively differentiated the Neandertals from the other groups, while the Broken Hill humerus appears morphologically similar to modern human distal humeri. Thus, an archaic/modern human dichotomy-as previously reported for proximal ulnar morphology-is not supported with respect to distal humeral morphology. Relative to australopiths and modern humans, Neandertal humeri are characterized by large olecranon fossae and small distodorsal medial and lateral pillars. The seeming disparity in morphological affinities of proximal ulnae (in which all archaic human groups appear distinct from modern humans) and distal humeri (in which Neandertals appear distinct from modern humans, but other archaic humans do not) is probably indicative of a highly variable, possibly transitional population of which our knowledge is hampered by sample-size limitations imposed by the scarcity of middle-to-late Pleistocene premodern human fossils outside of Europe. PMID:16959299

  8. Interlocked DNA nanostructures controlled by a reversible logic circuit.

    PubMed

    Li, Tao; Lohmann, Finn; Famulok, Michael

    2014-01-01

    DNA nanostructures constitute attractive devices for logic computing and nanomechanics. An emerging interest is to integrate these two fields and devise intelligent DNA nanorobots. Here we report a reversible logic circuit built on the programmable assembly of a double-stranded (ds) DNA [3]pseudocatenane that serves as a rigid scaffold to position two separate branched-out head-motifs, a bimolecular i-motif and a G-quadruplex. The G-quadruplex only forms when preceded by the assembly of the i-motif. The formation of the latter, in turn, requires acidic pH and unhindered mobility of the head-motif containing dsDNA nanorings with respect to the central ring to which they are interlocked, triggered by release oligodeoxynucleotides. We employ these features to convert the structural changes into Boolean operations with fluorescence labelling. The nanostructure behaves as a reversible logic circuit consisting of tandem YES and AND gates. Such reversible logic circuits integrated into functional nanodevices may guide future intelligent DNA nanorobots to manipulate cascade reactions in biological systems. PMID:25229207

  9. Interlocked DNA nanostructures controlled by a reversible logic circuit

    PubMed Central

    Li, Tao; Lohmann, Finn; Famulok, Michael

    2014-01-01

    DNA nanostructures constitute attractive devices for logic computing and nanomechanics. An emerging interest is to integrate these two fields and devise intelligent DNA nanorobots. Here we report a reversible logic circuit built on the programmable assembly of a double-stranded (ds) DNA [3]pseudocatenane that serves as a rigid scaffold to position two separate branched-out head-motifs, a bimolecular i-motif and a G-quadruplex. The G-quadruplex only forms when preceded by the assembly of the i-motif. The formation of the latter, in turn, requires acidic pH and unhindered mobility of the head-motif containing dsDNA nanorings with respect to the central ring to which they are interlocked, triggered by release oligodeoxynucleotides. We employ these features to convert the structural changes into Boolean operations with fluorescence labelling. The nanostructure behaves as a reversible logic circuit consisting of tandem YES and AND gates. Such reversible logic circuits integrated into functional nanodevices may guide future intelligent DNA nanorobots to manipulate cascade reactions in biological systems. PMID:25229207

  10. Shielding of the patient's gonads during intramedullary interlocking femoral nailing

    SciTech Connect

    Kwong, L.M.; Johanson, P.H.; Zinar, D.M.; Lenihan, M.R.; Herman, M.W. (Harbor/Univ. of California, Los Angeles Medical Center, Torrance (USA))

    1990-12-01

    Levels of exposure to radiation were recorded at sixty sites in fifteen patients during intramedullary interlocking femoral nailing. Radiation film dosimeters were placed at four gonadal sites on each subject. A standard male-gonad cup or a pelvic drape of 0.5-millimeter-thick lead-equivalent was put in place to shield the gonads. A second set of four dosimeters was placed external to the shield to approximate unprotected exposure. The total duration of the fluoroscopy averaged five minutes (range, thirty seconds to fourteen minutes). The total exposure to radiation external to the shield was 35 +/- 34 millirems at the male gonadal sites and 17 +/- 11 millirems at the female gonadal sites. With use of the gonadal shield, exposure to radiation was not measurable in thirteen of the fifteen patients. The differences between the exposures of the shielded and unshielded sites to radiation were statistically significant (p less than 0.001). The highest level of gonadal exposure was found with the treatment of proximal femoral fractures and with the use of statically locked nails. Regardless of the conditions, and for all types of fractures and locations, our results demonstrated that gonadal shielding is justified.

  11. An intensity ratio of interlocking loops determines circadian period length

    PubMed Central

    Yan, Jie; Shi, Guangsen; Zhang, Zhihui; Wu, Xi; Liu, Zhiwei; Xing, Lijuan; Qu, Zhipeng; Dong, Zhen; Yang, Ling; Xu, Ying

    2014-01-01

    Circadian clocks allow organisms to orchestrate the daily rhythms in physiology and behaviors, and disruption of circadian rhythmicity can profoundly affect fitness. The mammalian circadian oscillator consists of a negative primary feedback loop and is associated with some ‘auxiliary’ loops. This raises the questions of how these interlocking loops coordinate to regulate the period and maintain its robustness. Here, we focused on the REV-ERB?/Cry1 auxiliary loop, consisting of Rev-Erb?/ROR-binding elements (RORE) mediated Cry1 transcription, coordinates with the negative primary feedback loop to modulate the mammalian circadian period. The silicon simulation revealed an unexpected rule: the intensity ratio of the primary loop to the auxiliary loop is inversely related to the period length, even when post-translational feedback is fixed. Then we measured the mRNA levels from two loops in 10-mutant mice and observed the similar monotonic relationship. Additionally, our simulation and the experimental results in human osteosarcoma cells suggest that a coupling effect between the numerator and denominator of this intensity ratio ensures the robustness of circadian period and, therefore, provides an efficient means of correcting circadian disorders. This ratio rule highlights the contribution of the transcriptional architecture to the period dynamics and might be helpful in the construction of synthetic oscillators. PMID:25122753

  12. Isthmus-guided cortical bone trajectory for pedicle screw insertion.

    PubMed

    Iwatsuki, Koichi; Yoshimine, Toshiki; Ohnishi, Yu-ichiro; Ninomiya, Kosi; Ohkawa, Toshika

    2014-08-01

    Herein is described cortical bone trajectory (CBT), a new path for pedicle screw insertion for lumbar vertebral fusion. Because the points of insertion are under the end of the inferior articular process, and because the screws are inserted toward the lateral side, there is less soft tissue development than with the conventional technique; the CBT technique therefore enables less invasive surgery than the conventional technique. However, it has some drawbacks. For example, in the original CBT approach, the points of insertion are in the vicinity of the end of the inferior articular process. Because this joint has been destroyed in many patients who have indications for intervertebral fusion surgery, it is sometimes difficult to use it as a reference point for screw insertion location. With severe lateral slippage, the screw insertion site can become significantly dislocated sideways, with possible resultant damaging to the spinal canal and/or nerve root. The CBT technique here involved inserting the screws while keeping clear of the intervertebral foramen with the assistance of side view X-ray fluoroscopy and using the end of the inferior articular process and the isthmus as points of reference for screw location. PMID:25179360

  13. Distal penile prosthesis extrusion: treatment with distal corporoplasty or Gortex windsock reinforcement

    Microsoft Academic Search

    C C Carson; C H Noh

    2002-01-01

    Subcutaneous extrusion of penile prosthesis cylinders beneath the glans penis is an unusual but difficult complication of penile prosthesis. Without surgical repair, extrusion, infection, and corporeal fibrosis may ensue. Twenty-eight patients with distal corporeal extrusion were reviewed to identify the optimum treatment outcome for these penile prosthesis complications. Records of 28 men with subcutaneous distal penile prosthesis cylinder extrusion were

  14. Pullout strength of misplaced pedicle screws in the thoracic and lumbar vertebrae - A cadaveric study

    PubMed Central

    Saraf, Shyam K; Singh, Ravindra P; Singh, Vakil; Varma, Ashish

    2013-01-01

    Background: The objective of this cadaveric study was to analyze the effects of iatrogenic pedicle perforations from screw misplacement on the mean pullout strength of lower thoracic and lumbar pedicle screws. We also investigated the effect of bone mineral density (BMD), diameter of pedicle screws, and the region of spine on the pullout strength of pedicle screws. Materials and Methods: Sixty fresh human cadaveric vertebrae (D10–L2) were harvested. Dual-energy X-ray absorptiometry (DEXA) scan of vertebrae was done for BMD. Titanium pedicle screws of different diameters (5.2 and 6.2 mm) were inserted in the thoracic and lumbar segments after dividing the specimens into three groups: a) standard pedicle screw (no cortical perforation); b) screw with medial cortical perforation; and c) screw with lateral cortical perforation. Finally, pullout load of pedicle screws was recorded using INSTRON Universal Testing Machine. Results: Compared with standard placement, medially misplaced screws had 9.4% greater mean pullout strength and laterally misplaced screws had 47.3% lesser mean pullout strength. The pullout strength of the 6.2 mm pedicle screws was 33% greater than that of the 5.2 mm pedicle screws. The pullout load of pedicle screws in lumbar vertebra was 13.9% greater than that in the thoracic vertebra (P = 0.105), but it was not statistically significant. There was no significant difference between pullout loads of vertebra with different BMD (P = 0.901). Conclusion: The mean pullout strength was less with lateral misplaced pedicle screws while medial misplaced pedicle screw had more pullout strength. The pullout load of 6.2 mm screws was greater than that of 5.2 mm pedicle screws. No significant correlation was found between bone mineral densities and the pullout strength of vertebra. Similarly, the pullout load of screw placed in thoracic and lumbar vertebrae was not significantly different. PMID:23798753

  15. An analytical investigation of high-temperature heat pump system with screw compressor and screw expander for power recovery

    Microsoft Academic Search

    I. Tamura; H. Taniguchi; H. Sasaki; R. Yoshida; I. Sekiguchi; M. Yokogawa

    1997-01-01

    An analytical investigation of a high-temperature heat pump system was developed to estimate the thermal cycle and to assess the thermal fluids for their high-temperature delivery (up to 180°C) capacities without decomposition or the use of lubricant mechanisms. Then, a screw-type compressor was applied in the above conditions. Furthermore, a screw expander was also used as a replacement for the

  16. Screw Instability and Blandford-Znajek Mechanism

    E-print Network

    Li-Xin Li

    2000-01-25

    When magnetic field lines thread a rotating black hole's horizon and connect with remote astrophysical loads, the rotational energy of the black hole can be extracted through the Blandford-Znajek mechanism. Due to the rotation of the black hole, the magnetic field lines are twisted and toroidal components are generated. So poloidal electric currents are induced and the black hole's rotational energy is transported to the astrophysical loads through Poynting flux. The Blandford-Znajek mechanism has been considered to be a possible process for powering extragalactic jets. In this paper we show that due to the screw instability of magnetic field, the toroidal components of the magnetic field, and thus the poloidal currents, cannot exceed the limits given by the Kruskal-Shafranov criterion. This significantly lowers the power of the Blandford-Znajek mechanism when the loads are far from the black hole. So the Blandford-Znajek mechanism can only work efficiently within the neighborhood of the black hole. The implications of the results for the scenario of extragalactic jets powered by the Blandford-Znajek mechanism are discussed.

  17. MagScrew TAH: an update.

    PubMed

    Weber, Stephan; Kamohara, Keiji; Klatte, Ryan S; Luangphakdy, Viviane; Flick, Christine; Chen, Ji-Feng; Casas, Fernando; Ootaki, Yoshio; Kopcak, Michael; Akiyama, Masatoshi; Hirschman, Gordon B; Chapman, Peter A; Donahue, Arthur; Wetterau, William; Prisco, Charles; Mast, Roy; Sherman, Craig; Fukamachi, Kiyotaka; Smith, William A

    2005-01-01

    The MagScrew Total Artificial Heart (TAH) system is the result of a close collaboration among the Cleveland Clinic Foundation, Foster Miller Technologies, Wilson Greatbatch Ltd, and Whalen Biomedical Inc. The system components are the thoracic blood pumping unit with attached compliance chamber and refill port, implantable electronic control unit, implantable battery pack, transcutaneous energy transmission system, external battery pack, and a telemetry system for communication with the electronic control unit. System in vitro tests are underway for system characterization and durability demonstration, whereas in vivo tests were conducted to evaluate system performance and biocompatibility under physiologic conditions. The passively filling pump uses a left master alternate left and right ejection control mode and has a Starling law-like response to venous pressure. The in vitro tests documented excellent hydraulic pump performance with high device output of over 9 l/min at left atrial pressures below 12 mm Hg. Atrial balance was well maintained under all test conditions. The in vivo tests demonstrated good biocompatibility without use of anticoagulant therapy. Experimental durations have ranged between 0 and 92 days. Postexplant evaluation of tissue samples did not reveal any sign of thromboembolic events or tissue damage due to device operation. PMID:16340348

  18. Helical Screw Expander Evaluation Project. Final report

    SciTech Connect

    McKay, R.

    1982-03-01

    A functional 1-MW geothermal electric power plant that featured a helical screw expander was produced and then tested in Utah in 1978 to 1979 with a demonstrated average performance of approximately 45% machine efficiency over a wide range of test conditions in noncondensing operation on two-phase geothermal fluids. The Project also produced a computer-equipped data system, an instrumentation and control van, and a 1000-kW variable load bank, all integrated into a test array designed for operation at a variety of remote test sites. Additional testing was performed in Mexico in 1980 under a cooperative test program using the same test array, and machine efficiency was measured at 62% maximum with the rotors partially coated with scale, compared with approximately 54% maximum in Utah with uncoated rotors, confirming the importance of scale deposits within the machine on performance. Data are presented for the Utah testing and for the noncondensing phases of the testing in Mexico. Test time logged was 437 hours during the Utah tests and 1101 hours during the Mexico tests.

  19. Solid and hollow pedicle screws affect the electrical resistance: A potential source of error with stimulus-evoked electromyography

    PubMed Central

    Wang, Hongwei; Liao, Xinhua; Ma, Xianguang; Li, Changqing; Han, Jianda; Zhou, Yue

    2013-01-01

    Background: Although stimulus evoked electromyography (EMG) is commonly used to confirm the accuracy of pedicle screw placement. There are no studies to differentiate between solid screws and hollow screws to the electrical resistance of pedicle screws. We speculate that the electrical resistance of the solid and hollow pedicle screws may be different and then a potential source of error with stimulus-evoked EMG may happen. Materials and Methods: Resistance measurements were obtained from 12 pedicle screw varieties (6 screws of each manufacturer) across the screw shank based on known constant current and measured voltage. The voltage was measured 5 times at each site. Results: Resistance of all solid screws ranged from 0.084 ? to 0.151 ? (mean =0.118 ± 0.024 ?) and hollow screws ranged from 0.148 ? to 0.402 ? (mean = 0.285 ± 0.081 ?). There was a significant difference of resistance between the solid screws and hollow screws (P < 0.05). The screw with the largest diameter no matter solid screws or hollow screws had lower resistance than screws with other diameters. No matter in solid screws group or hollow screws group, there were significant differences (P < 0.05) between the 5.0 mm screws and 6.0 mm screws, 6.0 mm screws and 7.0 mm screws, 5.0 mm screws and 7.0 mm screws, 4.5 mm screws and 5.5 mm screws, 5.5 mm screws and 6.5 mm screws, 4.5 mm screws and 6.5 mm screws. The resistance of hollow screws was much larger than the solid screws in the same diameter group (P < 0.05). Conclusions: Hollow pedicle screws have the potential for high electrical resistance compared to the solid pedicle screws and therefore may affect the EMG response during stimulus-evoked EMG testing in pedicle screw fixation especially in minimally invasive percutaneous pedical screw fixation surgery. PMID:23960278

  20. The influence of screw configuration on the pretreatment performance of a continuous twin screw-driven reactor (CTSR).

    PubMed

    Choi, Chang Ho; Um, Byung-Hwan; Oh, Kyeong Keun

    2013-03-01

    A combination of a continuous twin screw-driven reactor (CTSR) and a dilute acid pretreatment was used for the pretreatment of biomass with a high cellulose content and high monomeric xylose hydrolyzate. With the newly modified CTSR screw configuration (Config. 3), the influences of the screw rotational speed (30-60 rpm), of the pretreatment conditions such as acid concentration (1-5%) and reaction temperature (160-175 °C) at the operating condition of biomass feeding rate (1.0 g/min) and acid feeding rate (13.4 mL/min) on the pretreatment performance were investigated. The cellulose content in the pretreated rape straw was 67.1% at the following optimal conditions: barrel temperature of 165 °C, acid concentration of 3.0% (w/v), and screw rotational speed of 30 rpm. According to the three screw configurations, the glucose yields from enzymatic hydrolysis were 70.1%, 72.9%, and 78.7% for screw Configs. 1, 2, and 3, respectively. PMID:23395738

  1. Atlantoaxial fixation using the polyaxial screw–rod system

    PubMed Central

    Vyskocil, Tomas; Sebesta, Petr; Kryl, Jan

    2006-01-01

    The aim of this study is to evaluate the first results of the atlantoaxial fixation using polyaxial screw–rod system. Twenty-eight patients followed-up 12–29 months (average 17.1 months) were included in this study. The average age was 59.5 years (range 23–89 years). The atlantoaxial fusion was employed in 20 patients for an acute injury to the upper cervical spine, in 1 patient with rheumatoid arthritis for atlantoaxial vertical instability, in 1 patient for C1–C2 osteoarthritis, in 2 patients for malunion of the fractured dens. Temporary fixation was applied in two patients for type III displaced fractures of the dens and in two patients for the atlantoaxial rotatory dislocation. Retrospectively, we evaluated operative time, intraoperative bleeding and the interval of X-ray exposure. The resulting condition was subjectively evaluated by patients. We evaluated also the placement, direction and length of the screws. Fusion or stability in the temporary fixation was evaluated on radiographs taken at 3, 6, 12 weeks and 6 and 12 months after the surgery. As concerns complications, intraoperatively we monitored injury of the nerve structures and the vertebral artery. Monitoring of postoperative complications was focused on delayed healing of the wound, breaking or loosening of screws and development of malunion. Operative time ranged from 35 to 155 min, (average 83 min). Intraoperative blood loss ranged from 50 to 1,500 ml (average 540 ml). The image intensifier was used for a period of 24 s to 2 min 36 s (average 1 min 6 s). Within the postoperative evaluation, four patients complained of paresthesia in the region innervated by the greater occipital nerve. A total of 56 screws were inserted into C1, their length ranged from 26 to 34 mm (average, 30.8 mm). All screws were positioned correctly in the C1 lateral mass. Another 56 screws were inserted into C2. Their length ranged from 28 to 36 mm (average 31.4 mm). Three screws were malpositioned: one screw perforated the spinal canal and two screws protruded into the vertebral artery canal. C1–C2 stability was achieved in all patients 12 weeks after the surgery. No clinically manifested injury of the vertebral artery or nerve structures was observed in any of these cases. As for postoperative complications, we recorded wound dehiscence in one patient. The Harms C1–C2 fixation is a very effective method of stabilizing the atlantoaxial complex. The possibility of a temporary fixation without damage to the atlantoaxial joints and of reduction after the screws and rods had been inserted is quite unique. PMID:17051397

  2. Silicone rubber distal ulnar replacement arthroplasty.

    PubMed

    Sagerman, S D; Seiler, J G; Fleming, L L; Lockerman, E

    1992-12-01

    We retrospectively reviewed 42 patients who underwent resection of the distal ulna with implantation of a silicone rubber ulnar head prosthesis (45 wrists). Two prostheses were used: the original Swanson prosthesis, and a prosthesis of our own design. Follow-up X-rays showed migration or breakage of 63% of the prostheses. No statistically significant correlation existed between the quality of functional outcome and the integrity of the prostheses. There was no significant difference between pre-operative and post-operative range of motion for the entire group or between patients with broken or intact prostheses. Histological confirmation of silicone synovitis was documented in one patient who required implant removal. We suggest that destabilization and breakage of prostheses result from fatigue failure secondary to the torque generated at the distal radio-ulnar joint during repeated pronation and supination. Use of a silicone rubber ulnar head prosthesis following distal ulna resection is not recommended. PMID:1484256

  3. Disorders of the distal radioulnar joint.

    PubMed

    Houdek, Matthew T; Wagner, Eric R; Moran, Steven L; Berger, Richard A

    2015-01-01

    The distal radioulnar joint is responsible for stable forearm rotation. Injury to this joint can occur following a variety of mechanisms, including wrist fractures, ligamentous damage, or degenerative wear. Accurate diagnosis requires a clear understanding of the anatomy and mechanics of the ulnar aspect of the wrist. Injuries can be divided into three major categories for diagnostic purposes, and these include pain without joint instability, pain with joint instability, and joint arthritis. New advancements in imaging and surgical technique can allow for earlier detection of injuries, potentially preserving joint function. In this article, the authors review the pertinent anatomy, biomechanics, and major abnormality involving the distal radioulnar joint. PMID:25285686

  4. Cardio-vascular activity of catestatin: interlocking the puzzle pieces.

    PubMed

    Mazza, R; Tota, B; Gattuso, A

    2015-01-01

    Catestatin (CST), the Chromogranin A (CgA)-derived cationic and hydrophobic peptide, firstly recognized as an endogenous inhibitor of catecholamine secretion, functions as a physiological brake of the adreno-sympathetic-chromaffin system. Its wide spectrum of activities includes relevant multilevel cardiovascular and antihypertensive influences. At central systemic level, CST seems to modulate the autonomic cardiovascular control possibly acting on baroreceptor afferent fibers of the nucleus tractus solitarius. This, as well as clinical and experimental (CgA-KO mice) evidences point to an important role of CST in the determinism and prevention of essential hypertension. At organ level, CST exerts myocardial (negative inotropy and lusitropy) effects and potently vasodilates endothelin-1 (ET-1)-preconstricted coronaries through ?2-adrenergic receptor (AR)-Gi/o protein-nitric oxide (NO)-cGMP signalling, while counterbalancing ? adrenergic (ISO) stimulation. The contractile myocardial effects have been deeply analysed in fish and amphibian hearts, highlighting finely diversified mechanisms of action. CST also acts as cardioprotective agent in both pre- and post-conditioning through NO-dependent mechanisms implicating the Reperfusion Injury Salvage Kinase (RISK) signalling and the activation of mitoKATP channels. The CST-elicited cardiotropic and coronarotropic influences, along with the recently discovered proangiogenic and regulatory effects in glucose and lipid metabolism, contribute to delineate an integrated and updated picture of the peptide which emerges as a pleiotropic hormone with a wide range of cytokine-like characteristics. The aim of this review is to interlock some older and more recent evidences which may help to better perceive the subtle links and differences among the puzzle pieces that still need to be deciphered. PMID:25386823

  5. Global ice-sheet system interlocked by sea level

    SciTech Connect

    Denton, G.H.; Hughes, T.J.; Karlen, W.

    1986-01-01

    Denton and Hughes postulated that sea level linked a global ice-sheet system with both terrestrial and grounded marine components during later Quaternary ice ages. Summer temperature changes near Northern Hemisphere melting margins initiated sea-level fluctuations that controlled marine components in both polar hemispheres. It was further proposed that variations of this ice-sheet system amplified and transmitted Milankovitch summer half-year insolation changes between 45 and 75/sup 0/N into global climatic changes. New tests of this hypothesis implicate sea level as a major control of the areal extent of grounded portions of the Antarctic Ice Sheet. But factors other than areal changes of the grounded Antarctic Ice Sheet may have strongly influenced Southern Hemisphere climate and terminated the last ice age simultaneously in both polar hemispheres. Atmospheric carbon dioxide linked to high-latitude oceans is the most likely candidate, but another potential influence was high-frequency climatic oscillations. It is postulated that variations in atmospheric carbon dioxide acted through an Antarctic ice shelf linked to the grounded ice sheet to produce and terminate Southern Hemisphere ice-age climate. It is further postulated that Milankovitch summer insolation combined with a warm-high frequency oscillation caused marked recession of Northern Hemisphere ice-sheet melting margins and the North Atlantic polar front about 14,000 /sup 14/C yr B.P. This permitted renewed formation of North Atlantic Deep Water, which could well have controlled atmospheric carbon dioxide. Combined melting and consequent sea-level rise from the three warming factors initiated irreversible collapse of the interlocked global ice-sheet system, which was at its largest but most vulnerable configuration.

  6. Treatment of Femoral Shaft Fracture with an Interlocking Humeral Nail in Older Children and Adolescents

    PubMed Central

    Park, Hoon

    2012-01-01

    Purpose Rigid interlocking nailing for femoral shaft fracture is ideal for use in adolescents in terms of stability of the fracture and convenience for the patient. However, numerous authors have reported that rigid interlocking nailing has some limitations in this age group due to the risk of complications. We evaluated the results of intramedullary nailing for femoral shaft fractures with an interlocking humeral nail in older children and adolescents. Materials and Methods We retrospectively reviewed records of patients treated with an interlocking humeral nail. Radiographs were examined for proximal femoral change and evidence of osteonecrosis. Outcomes were assessed by major or minor complications that occurred after operative treatment. Results Twenty-four femoral shaft fractures in 23 patients were enrolled. The mean age at the time of operation was 12 years and 8 months and the mean follow-up period was 21 months. Bony union was achieved in all patients without any complications related to the procedure such as infection, nonunion, malalignment and limb length discrepancy. All fractures were clinically and radiographically united within an average eight weeks. No patients developed avascular necrosis of the femoral head and coxa valga. Conclusion Intramedullary nailing through the greater trochanter using a rigid interlocking humeral nail is effective and safe for the treatment of femoral shaft fractures in older children and adolescents. PMID:22318831

  7. Long-term stability of angle-stable versus conventional locked intramedullary nails in distal tibia fractures

    PubMed Central

    2013-01-01

    Background In the last years intramedullary nailing has become the treatment of choice for most displaced diaphyseal tibia fractures. In contrast intramedullary nailing of distal tibia fractures is accompanied by problems like decreased biomechanical stability. Nevertheless the indications for intramedullary nailing have been extended to include even more distal fractures. The purpose of this study was to compare long-term mechanical characteristics of angle-stable versus conventional locked intramedullary nails in the treatment of unstable distal tibia fractures. Therefore, the effect of time on the mechanical properties of biodegradable sleeves was assessed. Methods 8 pairs of fresh, frozen porcine tibiae were used. The expert tibial nail (Synthes) was equipped with either three conventional locking screws (CL) or the angle-stable locking system (AS), consisting of a special ASLS screw and a biodegradable sleeve. Biomechanical testing included torsional and axial loading at different time-points over 12 weeks. Results The AS group showed a significantly higher torsional stiffness at all time-points (at least 60%) compared to the CL group (p??0.05). For axial stiffness and range of motion significant differences were found in the AS group. Conclusions The angle-stable locking system (ASLS) with the biodegradable sleeve provides significantly higher long-term stability. Especially the differences determined under torsional loading in this study may have clinical relevance. The ASLS permits the potential to decrease complications like secondary loss of reduction and mal-/non-union. PMID:23425016

  8. Anatomical measurement and finite element study on screw channel parameter in percutaneous fixation of canulated screw for symphyseolysis.

    PubMed

    Yu, Kehe; Hong, Jianjun; Sun, Yuefei; Shi, Chengdi; Guo, Xiaoshan; Zhou, Dongsheng

    2015-03-01

    To provide anatomical basement for symphyseolysis treatment with percutaneous fixation of canulated screw, through anatomical measurement on pubic symphysis and the surrounding tissues, and conduct the finite element studies on screw channel parameters. 20 cases of normal pelvic specimens from embalmed adult cadavers were taken to measure the anatomical parameter of bony remark of pubic symphysis and the space between spermatic cord (round ligament of the uterus) and pubic tubercle. Anatomical measurement results showed that the narrowest diameter of the superior ramus of pubis was 9.127 ± 1.189 mm, distance between two pubic tubercles was 55.656 ± 3.780 mm, thickness of the upper pubic symphysis was 10.510 ± 0.814 mm, and distance between upper and lower pubic symphysis was 40.872 ± 1.211 mm; the distance between round ligament of the uterus and pubic tubercle was 4.408 ± 0.304 mm, and the distance between spermatic cord and pubic tubercle was 5.196 ± 0.251 mm. The angle between canulated screw guide pin and horizontal plane was 8.342 ± 2.152°, the one between guide pin and coronal plane was 5.236 ± 1.612°, and the distance from entry point to the outer edge of pubic tubercle was 10.023 ± 1.245 mm, which was measured by Mimics software. Percutaneous surgery at horizontal position was simulated on cadaver. And the screw was correctly placed in postoperative imaging examination. According to the anatomical data and finite element studies of screw channel parameter in percutaneous fixation of canulated screw for symphyseolysis, the method can improve the accuracy of screw placement and reduce complications. PMID:25388836

  9. Prophylactic bioactive screw fixation as an alternative augmentation for femoroplasty.

    PubMed

    Hananouchi, Takehito

    2015-04-01

    Femoroplasty is theoretically a prophylactic surgical procedure for femoral neck fracture. Although bone cement is generally used for augmentation, its distribution cannot be easily controlled. This study investigated whether a bioactive screw is feasible for femoroplasty as an alternative augmentation material. A mechanical test was done to compare the strength of four types of augmentation bioactive screw (Superfixsorb), two bioinert cements, or no intervention in a composite femoral bone. The peak load to fracture under simulated falling was compared among the four groups. The mean peak load to failure in the bioactive screw group (2667 N) was significantly higher than that in the intact group (2391 N) (p=0.028), comparable to that in the Simplex P cement group (2864 N) (p=0.11), and significantly lower than that of the cranioplastic cement group (3022 N) (p=0.006). The strength of a composite femur with the bioactive screw was higher than that of an intact bone and comparable to one cement augmentation. Thus, this bioactive screw can be potentially used as augmentation material for femoroplasty. PMID:25581740

  10. Transsacral screw safe zone size by sacral segmentation variations.

    PubMed

    Lee, John J; Rosenbaum, Samuel L; Martusiewicz, Alex; Holcombe, Sven A; Wang, Stewart C; Goulet, James A

    2015-02-01

    Variations in sacral segmentation may preclude safe placement of transsacral screws for posterior pelvis fixation. We developed a novel automated 3D technique to determine the safe zone size for transsacral screws in the upper two sacral segments in 526 adult pelvis computed tomography scans. Safe zone sizes were then compared by gender and sacral segmentation variations (number of neuroforamen and the presence/absence of lumbosacral transitional vertebrae, ± LSTV). Ten millimeters was used as the safety threshold for a large screw. 3 (0.6%), 366 (70%), and 157 (30%) sacra had 3, 4, or 5 neuroforamen, respectively. Eighty-eight (17%) were +LSTV. Safe zone size depended on gender, number of neuroforamen in -LSTV sacra and presence of LSTV (p < 0.001) but not on the uni- or bilateral nature of the LSTV. 17% of -LSTV sacra were below the safety threshold in S1, 27% in S2, whereas 3% of +LSTV sacra were below in S1, 74% in S2. Of -LSTV sacra that cannot take an S1 screw safely, 77% can do so in S2, leaving only 4% of sacra that cannot accommodate a screw safely in either upper segment. The results demonstrate a predictable pattern of safe zone size based on gender and sacral segmentation variations. PMID:25231682

  11. Ball screw preload loss detection using ball pass frequency

    NASA Astrophysics Data System (ADS)

    Tsai, P. C.; Cheng, C. C.; Hwang, Y. C.

    2014-10-01

    A technique of determining the onset of preload loss in a ball screw feed drive system via monitoring the change of ball pass frequency is proposed. The ball pass frequency of a ball screw with preload is smaller than that of ball screw without preload due to friction caused by the preload. Results from both simulations and experiments show that the ball pass frequency can be detected using the method of Angular Velocity Vold-Kalman Filtering Order Tracking (AV VKF-OT). And AV VKF-OT provides a much better performance as compared to the traditional order tracking in terms of resolution and accuracy. Tests were conducted on ball screw feed drive systems with different preloads for the performance assessment of the ball pass frequency detection. Results show that the preload loss increases the ball pass frequency and also induces the side band around the ball pass frequency, which provides promising criteria in detecting the onset of preload loss of ball screws.

  12. Torsional properties of distal femoral cortical defects.

    PubMed

    Amanatullah, Derek F; Williams, Joel C; Fyhrie, David P; Tamurian, Robert M

    2014-03-01

    The optimal management of pathologic long bone lesions remains a challenge in orthopedic surgery. The goal of the current study was to investigate the effect of defect depth on the torsional properties of the distal femur. A laterally placed distal metaphyseal cylindrical defect was milled in the cortex of the distal femur in 20 composite models. The proximal extent of the defects was constant. By decreasing the radius of the cylinder that intersected this predefined cord, 4 different radii defining 4 different depths of resection of the distal femur were created for testing: 17%, 33%, 50%, and 67% cortical defects, when normalized to the width of the femur at the level of resection. Each femur was mounted into a hydraulic axial/torsion materials testing machine and each specimen underwent torsional stiffness testing and torsional failure in external rotation. The specimens with less than a 33% cortical loss consistently demonstrated a superiorly oriented spiral fracture pattern, while the specimens with greater than a 50% cortical loss consistently demonstrated an inferiorly oriented transverse fracture pattern. The cortical defects were all statistically (P<.05) less stiff in torsion as the defect grew larger. There was a strong linear correlation between the mean torsional stiffness and cortical defect size (r(2)=0.977). This observation is supported by finite element analysis. The amount of femur remaining is crucial to stability. This biomechanical analysis predicts a critical loss of torsional integrity when a cortical defect approaches 50% of the width of the femur. PMID:24762144

  13. Architecture for Interlock Systems Reliability Analysis with Regard to Safety and Availability

    E-print Network

    Wagner, S; Schmidt, R; Zerlauth, M; Vergara-Fernandez, A

    2011-01-01

    In the design of interlock loops for the signal exchange in machine protection systems, the choice of the hardware architecture impacts on machine safety and availability. The reliable performance of a machine stop (leaving the machine in a safe state) in case of an emergency, is an inherent requirement. The constraints in terms of machine availability on the other hand may differ from one facility to another. Spurious machine stops, lowering machine availability, may to a certain extent be tolerated in facilities where they do not cause undue equipment wearout. In order to compare various interlock loop architectures in terms of safety and availability, the occurrence frequencies of related scenarios have been calculated in a reliability analysis, using a generic analytical model. This paper presents the results and illustrates the potential of the analysis method for supporting the choice of interlock system architectures.

  14. Tactile-direction-sensitive and stretchable electronic skins based on human-skin-inspired interlocked microstructures.

    PubMed

    Park, Jonghwa; Lee, Youngoh; Hong, Jaehyung; Lee, Youngsu; Ha, Minjeong; Jung, Youngdo; Lim, Hyuneui; Kim, Sung Youb; Ko, Hyunhyub

    2014-12-23

    Stretchable electronic skins with multidirectional force-sensing capabilities are of great importance in robotics, prosthetics, and rehabilitation devices. Inspired by the interlocked microstructures found in epidermal-dermal ridges in human skin, piezoresistive interlocked microdome arrays are employed for stress-direction-sensitive, stretchable electronic skins. Here we show that these arrays possess highly sensitive detection capability of various mechanical stimuli including normal, shear, stretching, bending, and twisting forces. Furthermore, the unique geometry of interlocked microdome arrays enables the differentiation of various mechanical stimuli because the arrays exhibit different levels of deformation depending on the direction of applied forces, thus providing different sensory output patterns. In addition, we show that the electronic skins attached on human skin in the arm and wrist areas are able to distinguish various mechanical stimuli applied in different directions and can selectively monitor different intensities and directions of air flows and vibrations. PMID:25389631

  15. Joining mechanism with stem tension and interlocked compression ring

    DOEpatents

    James, Allister W.; Morrison, Jay A.

    2012-09-04

    A stem (34) extends from a second part (30) through a hole (28) in a first part (22). A groove (38) around the stem provides a non-threaded contact surface (42) for a ring element (44) around the stem. The ring element exerts an inward force against the non-threaded contact surface at an angle that creates axial tension (T) in the stem, pulling the second part against the first part. The ring element is formed of a material that shrinks relative to the stem by sintering. The ring element may include a split collet (44C) that fits partly into the groove, and a compression ring (44E) around the collet. The non-threaded contact surface and a mating distal surface (48) of the ring element may have conic geometries (64). After shrinkage, the ring element is locked onto the stem.

  16. The effect of fly ash content and types of aggregates on the properties of pre-fabricated concrete interlocking blocks (PCIBs)

    E-print Network

    North Texas, University of

    interlocking blocks (PCIBs) Tayfun Uygunoglu a , Ilker Bekir Topcu b , Osman Gencel c,d, , Witold Brostow d wastes in pre-fabricated concrete interlocking blocks (PCIBs). We have compared properties of PCIBs

  17. Mid- to long-term clinical findings in nailing of distal femoral fractures.

    PubMed

    Funovics, Philipp T; Vécsei, Vilmos; Wozasek, Gerald E

    2003-01-01

    The purpose of the study was to evaluate clinical long-term results after nailing of distal femoral fractures. The first 22 consecutive cases of distal femoral fractures in 22 patients (2 males and 20 females, age 65 years, range, 16-97 years) treated with retrograde femoral nailing from October 1994 to May 1997 are reported. Indications were AO 33 A1 (n = 7), 33 A2 (n = 2), 33 A3 (n = 3), and 33 C2 (n = 7) fractures. In 11 cases these were periprosthetic fractures of either total hip arthroplasty or hemiarthroplasty of the hip (five) or dynamic hip screw (six), four patients were polytraumatized, one patient had a floating-knee injury. No infections or thrombosis were observed postoperatively. In 17 cases primary union was achieved within 11 weeks (8-17 weeks); five patients died before consolidation. Patients returned to full weightbearing after 5 weeks (4-12 weeks); active knee motion ranged from 80 degrees to 130 degrees. In five patients slight malalignment < 10 degrees was radiographically assessed, with two showing incipient degenerative joint disease. Patients younger than 60 years returned to full preoperative activity level. Eleven patients surviving an average of 5.2 years (4.3-6.9 years) were available for long-term follow-up. As a subgroup they were evaluated according to the Leung score for distal femoral fractures with seven excellent and four good results and an average score of 84.3 points (70-92 points). The mid- to long-term results confirm retrograde femoral nailing to be a good alternative to plate osteosynthesis for AO 33 A- and C2-type fractures. In young patients (< 60 years) postoperative clinical performance was highly satisfying; however, the effects of postoperative hemarthros and anatomic malalignment on the cartilage surface remain major issues for further investigation. PMID:15008286

  18. Effects of Ignition Interlock Devices on DUI Recidivism: Findings from a Longitudinal Study in Hamilton County, Ohio

    Microsoft Academic Search

    Barbara J. Morse; Delbert S. Elliott

    1992-01-01

    As demands for more effective legal remedies for drunk driving escalate, a number of states have authorized judges to use breath analyzer ignition interlock devices as an optional sanction in drunk driving cases. This research presents initial findings from a quasi-experimental study designed to evaluate the effectiveness of interlock devices as a deterrent to a repeated drunk driving arrest in

  19. 49 CFR 1242.17 - Signals and interlockers (accounts XX-17-19 and XX-18-19).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 false Signals and interlockers (accounts XX-17-19 and XX-18-19). 1242.17 Section 1242.17 Transportation...Structures § 1242.17 Signals and interlockers (accounts XX-17-19 and XX-18-19). Separate common...

  20. 49 CFR 1242.17 - Signals and interlockers (accounts XX-17-19 and XX-18-19).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 false Signals and interlockers (accounts XX-17-19 and XX-18-19). 1242.17 Section 1242.17 Transportation...Structures § 1242.17 Signals and interlockers (accounts XX-17-19 and XX-18-19). Separate common...