Sample records for facet joint arthrosis

  1. Cervical facet joint kinematics during bilateral facet dislocation.

    PubMed

    Panjabi, Manohar M; Simpson, Andrew K; Ivancic, Paul C; Pearson, Adam M; Tominaga, Yasuhiro; Yue, James J

    2007-10-01

    Previous biomechanical models of cervical bilateral facet dislocation (BFD) are limited to quasi-static loading or manual ligament transection. The goal of the present study was to determine the facet joint kinematics during high-speed BFD. Dislocation was simulated using ten cervical functional spinal units with muscle force replication by frontal impact of the lower vertebra, tilted posteriorly by 42.5 degrees. Average peak rotations and anterior sliding (displacement of upper articulating facet surface along the lower), separation and compression (displacement of upper facet away from and towards the lower), and lateral shear were determined at the anterior and posterior edges of the right and left facets and statistically compared (P < 0.05). First, peak facet separation occurred, and was significantly greater at the left posterior facet edge, as compared to the anterior edges. Next, peak flexion rotation and anterior facet sliding occurred, followed by peak facet compression. The highest average facet translation peaks were 22.0 mm for anterior sliding, 7.9 mm for separation, 9.9 mm for compression and 3.6 mm for lateral shear. The highest average rotation of 63 degrees occurred in flexion, significantly greater than all other directions. These events occurred, on average, within 0.29 s following impact. During BFD, the main sagittal motions included facet separation, flexion rotation, anterior sliding, followed by compression, however, non-sagittal motions also existed. These motions indicated that unilateral dislocation may precede bilateral dislocation. PMID:17566792

  2. Image-guided facet joint injection

    PubMed Central

    Peh, WCG

    2011-01-01

    Chronic spine pain poses a peculiar diagnostic and therapeutic challenge due to multiple pain sources, overlapping clinical features and nonspecific radiological findings. Facet joint injection is an interventional pain management tool for facet-related spinal pain that can be effectively administered by a radiologist. This technique is the gold standard for identifying facet joints as the source of spinal pain. The major indications for facet injections include strong clinical suspicion of the facet syndrome, focal tenderness over the facet joints, low back pain with normal radiological findings, post-laminectomy syndrome with no evidence of arachnoiditis or recurrent disc disease, and persistent low back pain after spinal fusion. The contraindications are more ancillary, with none being absolute. Like any synovial joint degeneration, inflammation and injury can lead to pain on motion, initiating a vicious cycle of physical deconditioning, irritation of facet innervations and muscle spasm. Image-guided injection of local anesthetic and steroid into or around the facet joint aims to break this vicious cycle and thereby provide pain relief. This outpatient procedure has high diagnostic accuracy, safety and reproducibility but the therapeutic outcome is variable. PMID:21655113

  3. The Effects of Lumbar Facet Dowels on Joint Stiffness: A Biomechanical Study

    PubMed Central

    Trahan, Jayme; Morales, Eric; Richter, Erich O.; Tender, Gabriel C.

    2014-01-01

    Background Facet joint arthrosis may play a significant role in low back pain generation. The placement of facet dowels is a percutaneous treatment that aims to fuse the facets and increase joint stiffness. In this cadaveric study, we evaluated spine stiffness after facet dowel insertion in combination with several surgical procedures and determined which motions promote dowel migration. Methods Six fresh frozen lumbar spines were tested in flexion-extension, lateral bending, and axial rotation. Spine stiffness was determined for the intact specimens, after L4 laminectomy, and after bilateral L4-L5 facet dowel placement, respectively. One specimen underwent a unilateral transforaminal lumbar interbody fusion (TLIF) construct and another underwent extreme lateral interbody fusion (XLIF) graft (22 mm) placement, followed by placement of facet dowels. Afterwards, the specimens were subjected to 10,000 cycles of fatigue testing in flexion-extension or axial rotation. Results The overall decrease in stiffness after laminectomy was 4.6%. Facet dowel placement increased overall stiffness by 7.2%. The greatest increase was seen with axial rotation (13%), compared to flexion, extension, and lateral bending (9.5%, 2.3%, and 5.6%, respectively). The TLIF and XLIF plus dowel construct increased specimen stiffness to 266% and 163% of baseline, respectively. After fatigue testing, dowel migration was detected by computed tomography in the 2 uninstrumented specimens undergoing axial rotation cycling. Conclusion Facet dowels increase the stiffness of the motion segment to which they are applied and can be used in conjunction with laminectomy procedures to increase the stiffness of the joint. However, dowel migration can occur after axial rotation movements. Hybrid TLIF or XLIF plus facet dowel constructs have significantly higher stiffness than noninstrumented ones and may prevent dowel migration. PMID:24688332

  4. Pathogenesis, diagnosis, and treatment of lumbar zygapophysial (facet) joint pain.

    PubMed

    Cohen, Steven P; Raja, Srinivasa N

    2007-03-01

    Lumbar zygapophysial joint arthropathy is a challenging condition affecting up to 15% of patients with chronic low back pain. The onset of lumbar facet joint pain is usually insidious, with predisposing factors including spondylolisthesis, degenerative disc pathology, and old age. Despite previous reports of a "facet syndrome," the existing literature does not support the use of historic or physical examination findings to diagnose lumbar zygapophysial joint pain. The most accepted method for diagnosing pain arising from the lumbar facet joints is with low-volume intraarticular or medial branch blocks, both of which are associated with high false-positive rates. Standard treatment modalities for lumbar zygapophysial joint pain include intraarticular steroid injections and radiofrequency denervation of the medial branches innervating the joints, but the evidence supporting both of these is conflicting. In this article, the authors provide a comprehensive review of the anatomy, biomechanics, and function of the lumbar zygapophysial joints, along with a systematic analysis of the diagnosis and treatment of facet joint pain. PMID:17325518

  5. Three-dimensional evaluation of the facet joints

    NASA Astrophysics Data System (ADS)

    Folio, Les R.

    1990-04-01

    Computerized tomography and magnetic resonance imaging nave revolurionalized analysis of vertebral anatomy and pathology. Further advances with 3-dimensional imaging have recently become an important adjunct for diagnosis and treatment in structural abnormalities. Facets are intimately related to their surrounding musculature and malalignment may cause pain directly or indirectly. High resolution 3-dimensional reformations of CT Scans give us new insight on structure and function of facet joints, since their motion and architecture are ever complex. It is well documented in the literature that facet joint biomecnanics is a partial contributor to the myriad at causes of low back The term "facet Joint syndrome" was coined in 1933 by GhorMley.3 The osteopathic lesion complex is well defined by LeRoy and McCole and comparison of roentgenographic findings before and after manipulation has teen described by Long and Lioyd.4,5 since alterations in facet biamechanics are an important aspect of osteopathic manipulative therapy (OT), 3-dimensional hign resolution imaging will prove to be a great asset in osteopathic research. Rotating the spine allows for different viewing perspectives to provide optimal and consistent measurements of the facet joint. Rotations are performed on the X, Y and 7, axis and measurements pre and post-manipulation are performed and compared on matching axis and perspectives. Rotation about the X, Y and Z axis help appreciate the 3-dimensionality of the vertebral column to project to the viewer a feeling that the spine is floating in space before them. This does give the viewer a 3-D understanding of the object however, only at a perspective at a Lime.

  6. Quantitative ultrasound assessment of the facet joint in the lumbar spine: a feasibility study.

    PubMed

    Liu, Da; Huang, Ying; Tian, Dan; Yin, Jing

    2015-05-01

    This study was designed to determine the feasibility and accuracy of a sonographic approach to assessment of facet joints of the lumbar spine in healthy populations. Five facet joints (L1-S1) on each side of 30 volunteers, for a total of 300 facet joints, were examined and evaluated by sonography and computed tomography. Parameters of the facet joints (height and width) were established to assess the facet joint in the parasagittal and transverse planes on all volunteers. Differences between means of continuous variables including age, height, weight, body surface area, body mass index and joint parameters were evaluated with Student's t-test. Stepwise multiple regression analysis was used to evaluate the associations between the mean values of facet joint parameters and age, height, body surface area and body mass index. In general, sonography revealed that facet joints had a clear and smooth border. There were no significant differences in width and height between the left and right facet joints at the same level by sonography. Stepwise multiple regression analysis revealed that body mass index and age (p < 0.05) were the only independent factors modulating height of the facet joint. Facet joint width was independently influenced by age (p < 0.01). There were no significant differences between ultrasound and computed tomography in mean measurements of height (1.23 ± 0.15 vs. 1.25 ± 0.07, p > 0.05) and width (0.17 ± 0.08 vs. 0.18 ± 0.07, p > 0.05) of the facet joint, respectively. In this article, we describe a feasible, accurate and simple technique for identification and depiction of facet joints of the lumbar spine in healthy populations. PMID:25638321

  7. Percutaneous CT-Guided Treatment of Lumbar Facet Joint Synovial Cysts

    Microsoft Academic Search

    Anthony Chang

    2009-01-01

    Symptomatic intraspinal lumbar facet joint synovial cysts can be managed both conservatively and surgically. Diagnosis of\\u000a the lumbar facet joint cyst is made through cross-sectional imaging of the spine, either by computerized tomography (CT) scan,\\u000a myelography, or most commonly magnetic resonance imaging. Conservative treatment by facet joint injection can be performed\\u000a under fluoroscopic or CT guidance, although only CT guidance

  8. Association between facet joint osteoarthritis and the Oswestry Disability Index

    PubMed Central

    Maataoui, Adel; Vogl, Thomas J; Middendorp, Marcus; Kafchitsas, Konstantinos; Khan, M Fawad

    2014-01-01

    AIM: To investigate the correlation of facet joint osteoarthritis (FJOA) at lumbar levels L4/L5 and L5/S1 and the Oswestry Disability Index (ODI). METHODS: The study involved lumbar MRIs of 591 patients with a mean age of 47.3 years. The MRIs of the lumbar spine were performed on a 1.5 Tesla scanner (Magnetom® Avanto, Siemens AG, Erlangen, Germany) using a dedicated receive only spine coil. After initial blinding, each dataset was evaluated by 2 board certified radiologist with more than 5 years experience in musculoskeletal imaging. In total 2364 facet joints were graded. Degenerative changes of the facet joints were evaluated according to the 4-point scale as proposed by Weishaupt et al Functional status was assessed using the ODI. The index is scored from 0 to 100 and interpreted as follows: 0%-20%, minimal disability; 20%-40%, moderate disability; 40%-60%, severe disability; 60%-80%, crippled; 80%-100%, patients are bedbound. Spearman’s coefficient of rank correlation was used for statistical analysis, with significance set at P < 0.05. RESULTS: In total 2364 facet joints at lumbar levels L4/5 and L5/S1 were analysed in 591 individuals. FJOA was present in 97% (L4/L5) and 98% (L5/S1). At level L4/5 (left/right) 17/15 (2.9%/2.5%) were described as grade 0, 146/147 (24.7%/24.9%) as grade 1, 290/302 (49.1%/51.1%) as grade 2 and 138/127 (23.4%/21.5%) as grade 3. At level L5/S1 (left/right) 10/11 (1.7%/1.9%) were described as grade 0, 136/136 (23.0%/23.0%) as grade 1, 318/325 (53.8%/55.0%) as grade 2 and 127/119 (21.5%/20.1%) as grade 3. Regarding the ODI scores, patients’ disability had a minimum of 0% and a maximum of 91.11% with an arithmetic mean of 32.77% ± 17.02%. The majority of patients (48.39%) had moderate functional disability (21%-40%). There was no significant correlation between FJOA and ODI on both sides of lumbar level L4/5 and on the left side of lumbar level L5/S1. A weak positive correlation was evaluated between ODI and FJOA on the right side of lumbar level L5/S1. CONCLUSION: The missing correlation of FJOA and ODI confirms our clinical experience that imaging alone is an insufficient approach explaining low back pain. Clinical correlation is imperative for an adequate diagnostic advance in patients with low back pain. PMID:25431643

  9. Cervical spine vertebral and facet joint kinematics under whiplash.

    PubMed

    Yoganandan, N; Pintar, F A; Klienberger, M

    1998-04-01

    Whiplash injuries sustained during a rear-end automobile collision have significant societal impact. The scientific literature on whiplash loading is both diverse and confusing. Definitive studies are lacking to describe the local mechanisms of injury that induce either acute or chronic pain symptoms. A methodology has been presented to quantify the kinematics of the cervical spine components by inducing controlled whiplash-type forces to intact human head-neck complexes. The localized facet joint kinematics and the overall segmental motions of the cervical spine are presented. It is anticipated that the use of this methodology will assist in a better delineation of the localized mechanisms of injury leading to whiplash pain. PMID:10412396

  10. Prevalence of facet joint pain in chronic spinal pain of cervical, thoracic, and lumbar regions

    Microsoft Academic Search

    Laxmaiah Manchikanti; Mark V Boswell; Vijay Singh; Vidyasagar Pampati; Kim S Damron; Carla D Beyer

    2004-01-01

    BACKGROUND: Facet joints are a clinically important source of chronic cervical, thoracic, and lumbar spine pain. The purpose of this study was to systematically evaluate the prevalence of facet joint pain by spinal region in patients with chronic spine pain referred to an interventional pain management practice. METHODS: Five hundred consecutive patients with chronic, non-specific spine pain were evaluated. The

  11. Treatment of patients with arthrosis of the temporomandibular joint by infiltration of sodium hyaluronate: a preliminary study

    Microsoft Academic Search

    L. Guarda-Nardini; R. Tito; A. Staffieri; A. Beltrame

    2002-01-01

    Patients with degenerative disease of the temporomandibular joint (TMJ) who did not respond to conservative medical therapy (splint therapy, selected grinding or physiotherapy) can be treated by arthrocentesis, which is associated with intra-articular injections of sodium hyaluronate (Hyalgan). In this study, we treated ten dysfunctional patients with degenerative joint disease (DJD) who had been diagnosed clinically and had had the

  12. The relationship between lower neck shear force and facet joint kinematics during automotive rear impacts.

    PubMed

    Stemper, Brian D; Yoganandan, Narayan; Pintar, Frank A; Maiman, Dennis J

    2011-04-01

    A primary goal of biomechanical safety research is the definition of localized injury thresholds in terms of quantities that are repeatable and easily measureable during experimentation. Recent biomechanical experimentation using human cadavers has highlighted the role of lower cervical facet joints in the injury mechanism resulting from low-speed automotive rear impacts. The present study was conducted to correlate lower neck forces and moments with facet joint motions during simulated rear impacts in an effort to define facet joint injury tolerance thresholds that can be used to assess automobile safety. Four male and four female intact head-neck complexes were obtained from cadaveric specimens and subjected to simulated automotive rear impacts using a pendulum-minisled device. Cervical spine segmental angulations and localized facet joint kinematics were correlated to shear and axial forces, and bending moments at the cervico-thoracic junction using linear regression. R(2) coefficients indicated that spinal kinematics correlated well with lower neck shear force and bending moment. Correlation slope was steeper in female specimens, indicating greater facet joint motions for a given loading magnitude. This study demonstrated that lower neck loads can be used to predict lower cervical facet joint kinematics during automotive rear impacts. Higher correlation slope in female specimens corresponds to higher injury susceptibility in that population. Although lower neck shear force and bending moment demonstrated adequate correlation with lower cervical facet joint motions, shear force is likely the better predictor due to similarity in the timing of peak magnitudes with regard to maximum facet joint motions. PMID:21433081

  13. Material Properties of the Human Lumbar Facet Joint Capsule

    PubMed Central

    Little, Jesse S.; Khalsa, Partap S.

    2005-01-01

    The human facet joint capsule is one of the structures in the lumbar spine that constrains motions of vertebrae during global spine loading (e.g., physiological flexion). Computational models of the spine have not been able to include accurate nonlinear and viscoelastic material properties, as they have not previously been measured. Capsules were tested using a uniaxial ramp-hold protocol or a haversine displacement protocol using a commercially available materials testing device. Plane strain was measured optically. Capsules were tested both parallel and perpendicular to the dominant orientation of the collagen fibers in the capsules. Viscoelastic material properties were determined. Parallel to the dominant orientation of the collagen fibers, the complex modulus of elasticity was E* = 1.63MPa, with a storage modulus of E? = 1.25MPa and a loss modulus of: E? = 0.39MPa. The mean stress relaxation rates for static and dynamic loading were best fit with first-order polynomials: B (?) = 0.1110 ? ? 0.0733 and B (?) = ?0.1249? 11794-8181 +0.0190, respectively. Perpendicular to the collagen fiber orientation, the viscous and elastic secant moduli were 1.81 and 1.00 MPa, respectively. The mean stress relaxation rate for static loading was best fit with a first-order polynomial: B (?) = ? 0.04? ? 0.06. Capsule strength parallel and perpendicular to collagen fiber orientation was 1.90 and 0.95 MPa, respectively, and extensibility was 0.65 and 0.60, respectively. Poisson’s ratio parallel and perpendicular to fiber orientation was 0.299 and 0.488, respectively. The elasticity moduli were nonlinear and anisotropic, and capsule strength was larger aligned parallel to the collagen fibers. The phase lag between stress and strain increased with haversine frequency, but the storage modulus remained large relative to the complex modulus. The stress relaxation rate was strain dependent parallel to the collagen fibers, but was strain independent perpendicularly. PMID:15868784

  14. Contact characteristics of the subtalar joint: load distribution between the anterior and posterior facets.

    PubMed

    Wagner, U A; Sangeorzan, B J; Harrington, R M; Tencer, A F

    1992-07-01

    The pressure distribution properties of the normal talocalcaneal joint were studied in 13 fresh cadaver specimens using pressure-sensitive film. The film was inserted into the joint through a posterior approach for the posterior facet and an anteromedial approach for the anterior/middle facet. Specimens, comprising the distal half of the tibia and fibula and the intact ankle and foot, were positioned in neutral in the sagittal plane. In the coronal plane, specimens were positioned in neutral, inversion, or eversion, and the contact characteristics were determined in varying positions, with and without loading the fibula, under axial loads of 350 N, 700 N, 1,050 N, and 1,400 N. The transducers were video imaged for quantitative analysis of area and pressure. The contact/joint area ratio increased significantly with applied load in the posterior facet [e.g., in eversion from 0.336 (SD = 0.195) at 350 N to 0.631 (SD = 0.225) at 700 N], as did the proportion of the contact area greater than 6 MPa, indicating an increase in contact pressure. The contact/joint area ratio was significantly lower in inversion than in any other position of the foot; however, high-pressure zones were similar, indicating that higher pressures occur in inversion. In the anterior/middle facets both contact/joint area ratio and high pressure/contact area ratios increased significantly to 700 N, but not with further load increase. At 350 N the anterior/middle facet contact area was 31% that of the posterior facet, yet it carried 63.3% of the load of the posterior facet, so its mean contact pressure was 1.44 MPa compared with 0.93 MPa for the posterior facet.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1613627

  15. Presence of NGF and its receptor TrkA in degenerative lumbar facet joint specimens

    Microsoft Academic Search

    M. F. Surace; D. Prestamburgo; M. Campagnolo; A. Fagetti; L. Murena

    2009-01-01

    In a preliminary study, the recurrent presence of nervous terminations was demonstrated with optical microscopy in several\\u000a slides of degenerative lumbar facet joints and surrounding soft tissues. The purpose of this study was to prove the presence\\u000a of NGF (nerve growth factor) and its receptor TrkA (tyrosine kinase receptor) with immunofluorescence. The peri\\/articular\\u000a tissues were harvested from the lumbar facet

  16. The lumbar facet joint: a review of current knowledge: Part II: diagnosis and management

    Microsoft Academic Search

    Gerard P. Varlotta; Todd R. Lefkowitz; Mark Schweitzer; Thomas J. Errico; Jeffrey Spivak; John A. Bendo; Leon Rybak

    2011-01-01

    This article is the second article in a two-part review on lumbar facet joint pathology. In this review, we discuss the current\\u000a concepts and controversies regarding the proper diagnosis and management of patients presenting with presumed facet-mediated\\u000a lower back pain. All efforts were made to include the most relevant literature from the fields of radiology, orthopaedics,\\u000a physiatry, and pain management.

  17. Osteochondroma arising from a lumbar facet joint in a 16-year-old.

    PubMed

    Hancock, Graeme E; Mariathas, Chrishan; Fernandes, James A; Breakwell, Lee M; Cole, Ashley A; Michael, Antony L R

    2015-05-01

    Osteochondromas are benign tumours of bony or cartilaginous origin, which may be solitary or multiple. They are rare in the axial skeleton and have previously been reported to arise from facet joints only in four cases in the English literature. We report the case of a 16-year-old girl who presented with a palpable bony lump and a short history of back pain. Imaging showed a bony lesion arising from a left-sided facet joint in the lumbar spine. Following excision biopsy, there was complete resolution of symptoms. The literature on the origin and management of spinal osteochondromas is discussed. PMID:25811920

  18. A Novel Modality for Facet Joint Denervation: Cooled Radiofrequency Ablation for Lumbar Facet Syndrome. A Case Series

    PubMed Central

    McCormick, Zachary L; Walker, Jeremy; Marshall, Benjamin; McCarthy, Robert; Walega, David R

    2015-01-01

    Background While cooled radiofrequency ablation (C-RFA) appears to be a promising technology for joint denervation, outcomes of this technique for the treatment of lumbar facet syndrome have not been described. We report clinical outcomes in a case series of patients treated with C-RFA for lumbar facet syndrome. Methods Consecutive patients aged 18-60 years diagnosed with lumbar facet syndrome, confirmed by ?75% symptom relief with at least one set of diagnostic medial branch nerve blocks, who underwent C-RFA between January 2007 and December 2013 in an urban academic pain center were included. The respective proportions of participants who reported ?50% improvement in pain and in function were calculated. Change in median NRS score, daily morphine equivalent consumption (DME), and medication quantification scale III (MQS III) score were measured. Results Twelve patients underwent C-RFA; three were lost to follow-up. The median and 25%-75% interquartile range (IQR) for age was 44 years (35, 54). The median duration of follow-up was 34 months, IQR (21, 55). The percentage and 95% confidence interval (CI) of patients who reported ?50% improvement in pain was 33% CI (12%, 64%) and in function was 78%, CI (41%, 96%). There was no significant change in DME or MSQ III score. Approximately 50% of patients sought additional healthcare by long-term follow-up. No complications were reported. Conclusions This case series suggests that C-RFA may improve function and to a lesser degree pain at long-term follow-up. A randomized, controlled trial is warranted.

  19. Finite element modeling approaches of human cervical spine facet joint capsule

    Microsoft Academic Search

    Srirangam Kumaresan; Narayan Yoganandan; Frank A Pintar

    1998-01-01

    The human cervical spine facet joint capsule was modeled using four nonlinear finite element approaches: slideline, contact surface, hyperelastic, and fluid models. Slideline elements and contact surface definitions were used in the first two models to simulate the synovial fluid between the articulating cartilages. Incompressible solid elements approximated the synovial fluid in the hyperelastic model. Hydrostatic fluid elements idealized the

  20. Subchondral Bone Failure in an Equine Model of Overload Arthrosis

    Microsoft Academic Search

    R. W Norrdin; C. E Kawcak; B. A Capwell; C. W McIlwraith

    1998-01-01

    Gross examination of metacarpo-\\/metatarsophalangeal (fetlock) joints from racehorses revealed defects on the condylar surface that ranged from cartilage fibrillation and erosion to focal cartilage indentations and cavitation in subchondral bone characteristic of traumatic osteochondrosis. Because these lesions represented a spectrum of mechanically induced arthrosis in which microdamage is thought to play a role, a histologic study of sagittal sections was

  1. Determination of spinal facet joint loads from extra articular strains--a theoretical validation.

    PubMed

    Luo, Z P; Buttermann, G R; Lewis, J L

    1996-06-01

    Loads on the facet joints of the lumbar spine may play a role in low back pain. Abnormal loading of the facets, either primarily or as a consequence of disc degeneration, may accelerate their degeneration. Study of these phenomena is difficult, since here are few methods for a direct measure of facet forces occurring in vivo. The authors developed a method for the direct measure of facet forces in a canine animal model of spine disease using strain gages. The method used empirical calibration of the strain gages, which was used to reduce experimental strain output to facet force during function. In this Technical Note, a theoretical model is formulated, solved and validated which gives a theoretical basis for the data reduction method. The facet is modeled as a cantilevered plate and deformations, as function of applied normal load, solved for using a finite difference method. The model is validated by comparison with two experiments with strain-gaged facets. Results from the model show that a minimum of three strain gages is required to determine uniquely the location and magnitude of an applied load to the facet, and that at least two gages should be placed in the region where the cranial articular process joins the pedicle with the gage axis parallel to that of the process. Plate surface strains were found to be insensitive to changes in the area of the applied loads, for a given resultant force magnitude. The method may be useful in other applications in which resultant force magnitude and location need to be measured on plate-like structures. PMID:9147975

  2. Arthrosis of the knee in chronic anterior laxity.

    PubMed

    Dejour, H; Walch, G; Deschamps, G; Chambat, P

    2014-02-01

    Arthrosis following rupture of the anterior cruciate ligament has been analysed in two series. The first series was derived from a review of 150 cases of reconstruction of the anterior cruciate ligament with a follow-up of 3 years or more. Arthrosis was seen to have developed in 13.3%. The second series was concerned with 64 cases of unilateral arthrosis treated by upper tibial valgus osteotomy in whom there had been a previous rupture of the anterior cruciate ligament. The 'tolerance interval'--that is the time between the original ligamentous injury and the time of osteotomy--for the development of arthrosis was very variable, ranging in the natural-history cases from 10 to 50 years, with a mean of 35 years. It is important to recognise the radiological signs of the onset of arthrosis. These are osteophytosis of the intercondylar notch, osteophyte formation at the posterior part of the medial tibial plateau, and, in particular, narrowing of the medial joint line with posterior subluxation of the medial femoral condyle, well seen in lateral radiographs whilst standing on one lower limb. Early arthroses, appearing after 10 years, may occur as a 'natural arthrosis', but it develops much more frequently after surgical treatment that had failed to correct anterior laxity and particularly when it had been performed on knees that were already pre-arthrotic. The main factor in arthrosis is anterior laxity measured radiologically by an 'active Lachman' radiograph. Removal of the medial meniscus which in itself, is liable to produce arthrosis, is even more harmful in anterior cruciate laxity since it doubles the degree of anterior subluxation of the tibia seen on unilateral weight-bearing. The development of varus deformity, which characterises progressive arthrosis, has its origin in wear of the posterior part of the medial tibial plateau caused by anterior cruciate laxity. Other factors play an important part such as associated lateral laxity, constitutional genu varum and weakness of the hamstring muscles, which oppose the subluxating action of the quadriceps. PMID:24461232

  3. Neuronal hyperexcitability in the dorsal horn after painful facet joint injury

    PubMed Central

    Quinn, Kyle P.; Dong, Ling; Golder, Francis J.; Winkelstein, Beth A.

    2010-01-01

    Excessive cervical facet capsular ligament stretch has been implicated as a cause of whiplash-associated disorders following rear-end impacts, but the pathophysiological mechanisms that produce chronic pain in these cases remain unclear. Using a rat model of C6/C7 cervical facet joint capsule stretch that produces sustained mechanical hyperalgesia, the presence of neuronal hyperexcitability was characterized 7 days after joint loading. Extracellular recordings of spinal dorsal horn neuronal activity between C6 and C8 (117 neurons) were obtained from anesthetized rats, with both painful and non-painful behavioral outcomes established by the magnitude of capsule stretch. The frequency of neuronal firing during noxious pinch (p<0.0182) and von Frey filaments applications (4–26 g) to the forepaw was increased (p<0.0156) in the painful group compared to the non-painful and sham groups. In addition, the incidence and frequency of spontaneous and afterdischarge firing were greater in the painful group (p<0.0307) relative to sham. The proportion of cells in the deep laminae that responded as wide dynamic range neurons also was increased in the painful group relative to non-painful or sham groups (p<0.0348). These findings suggest that excessive facet capsule stretch, while not producing visible tearing, can produce functional plasticity of dorsal horn neuronal activity. The increase in neuronal firing across a range of stimulus magnitudes observed at day 7 post-injury provides the first direct evidence of neuronal modulation in the spinal cord following facet joint loading, and suggests that facet-mediated chronic pain following whiplash injury is driven, at least in part, by central sensitization. PMID:20739124

  4. Spinal neuronal plasticity is evident within 1 day after a painful cervical facet joint injury

    PubMed Central

    Crosby, Nathan D.; Weisshaar, Christine L.; Winkelstein, Beth A.

    2013-01-01

    Excessive stretch of the cervical facet capsular ligament induces persistent pain and spinal plasticity at later time points. Yet, it is not known when such spinal modifications are initiated following this painful injury. This study investigates the development of hyperalgesia and neuronal hyperexcitability in the spinal cord after a facet joint injury. Behavioral sensitivity was measured in a model of painful C6/C7 facet joint injury in the rat, and neuronal hyperexcitability in the spinal cord was evaluated at 6 hours and 1 day after injury or a sham procedure, in separate groups. Extracellular recordings of C6/C7 dorsal horn neuronal activity (229 neurons) were used to quantify spontaneous and evoked firing. Rats exhibited no change in sensitivity to mechanical stimulation of the forepaw at 6 hours, but did exhibit increased sensitivity at 1 day after injury (p=0.012). At 6 hours, both spontaneous neuronal activity and firing evoked by light brushing, pinch, and von Frey filaments (1.4–26g) applied at the forepaw were not different between sham and injury. At 1 day, spontaneous firing was noted in a greater number of neurons after injury than sham (p<0.04). Evoked firing was also increased 1 day after injury compared to normal and sham (p<0.03). Dorsal horn hyperexcitability and increased spontaneous firing developed between 6 and 24 hours after painful facet injury, suggesting that the development of hyperalgesia parallels dorsal horn hyperexcitability following mechanical facet joint injury, and these spinal mechanisms are initiated as early as 1 day after injury. PMID:23523644

  5. Finite element modeling approaches of human cervical spine facet joint capsule.

    PubMed

    Kumaresan, S; Yoganandan, N; Pintar, F A

    1998-04-01

    The human cervical spine facet joint capsule was modeled using four nonlinear finite element approaches: slideline, contact surface, hyperelastic, and fluid models. Slideline elements and contact surface definitions were used in the first two models to simulate the synovial fluid between the articulating cartilages. Incompressible solid elements approximated the synovial fluid in the hyperelastic model. Hydrostatic fluid elements idealized the synovial fluid in the fluid model. The finite element analysis incorporated geometric, material and contact nonlinearities. All models were subjected to compression, flexion, extension, and lateral bending. The fluid model idealization better approximates the actual facet joint anatomy and its behavior than the gap assumption in the slideline and contact surface models, and the solid element simulation in the hyperelastic model. PMID:9672091

  6. Axial head rotation increases facet joint capsular ligament strains in automotive rear impact

    Microsoft Academic Search

    Steven G. Storvik; Brian D. Stemper

    2011-01-01

    Axial head rotation prior to low speed automotive rear impacts has been clinically identified to increase morbidity and symptom\\u000a duration. The present study was conducted to determine the effect of axial head rotation on facet joint capsule strains during\\u000a simulated rear impacts. The study was conducted using a validated intact head to first thoracic vertebra (T1) computational\\u000a model. Parametric analysis

  7. Congenital absence of lumbosacral articular facet joint associated with conjoined nerve root: a case report

    Microsoft Academic Search

    Shinji Yoshioka; Koichi Sairyo; Toshinori Sakai; Natsuo Yasui

    2010-01-01

    We report a rare case of congenital absence of the L5-S1 facet joint, which was associated with a conjoined nerve root. Combination\\u000a of these two anomalies has been quite rarely reported in the literature. A 39-year-old man presented with acute low back pain\\u000a and right leg radiating pain. Muscle weakness and sensory disturbance of the right leg were also apparent

  8. Pigmented villonodular synovitis originating from the lumbar facet joint: a case report

    Microsoft Academic Search

    Kenichi Oe; Kunihiko Sasai; Yugo Yoshida; Hiroyuki Ohnari; Hirokazu Iida; Noriko Sakaida; Yoshiko Uemura

    2007-01-01

    The authors successfully treated a rare case of pigmented villonodular synovitis (PVNS) that originated from the lumbar facet\\u000a joint (L4-5). A 43-year-old man presented with a complaint of left severe sciatica causing difficulty in walking. Magnetic\\u000a resonance imaging (MRI) demonstrated an extradural mass on the left side at L4 and the mass compressed the dural tube and\\u000a was continuous with

  9. CT-Guided Transfacet Pedicle Screw Fixation in Facet Joint Syndrome: A Novel Approach.

    PubMed

    Manfré, Luigi

    2014-10-31

    Axial microinstability secondary to disc degeneration and consequent chronic facet joint syndrome (CFJS) is a well-known pathological entity, usually responsible for low back pain (LBP). Although posterior lumbar fixation (PIF) has been widely used for lumbar spine instability and LBP, complications related to wrong screw introduction, perineural scars and extensive muscle dissection leading to muscle dysfunction have been described. Radiofrequency ablation (RFA) of facet joints zygapophyseal nerves conventionally used for pain treatment fails in approximately 21% of patients. We investigated a "covert-surgery" minimal invasive technique to treat local spinal instability and LBP, using a novel fully CT-guided approach in patients with axial instability complicated by CFJS resistant to radioablation, by introducing direct fully or partially threaded transfacet screws (transfacet fixation - TFF), to acquire solid arthrodesis, reducing instability and LBP. The CT-guided procedure was well tolerated by all patients in simple analogue sedation, and mean operative time was approximately 45 minutes. All eight patients treated underwent clinical and CT study follow-up at two months, revealing LBP disappearance in six patients, and a significant reduction of lumbar pain in two. In conclusion, CT-guided TFF is a fast and safe technique when facet posterior fixation is needed. PMID:25363265

  10. Experimental Arthrosis by Hyperpressure

    Microsoft Academic Search

    J Bejui; M F Harmand; R Duphil; P Roussouly; J J Comtet; G Anania

    1986-01-01

    The frequent occurrence of degenerative joint disease (DJD) pathology and the high degree of functional prejudice associated with it, justify the search for experimental models with a view to a better understanding of this pathology and its treatment. The models most commonly used resort to a sudden mechanical degradation by shock (post-contusive osteoarthritis) or to a kinematic disruption of the

  11. An experimental method for measuring force on the spinal facet joint: description and application of the method.

    PubMed

    Buttermann, G R; Kahmann, R D; Lewis, J L; Bradford, D S

    1991-11-01

    A technique is described for measuring load magnitude and resultant load contact location in the facet joint in response to applied loads and moments, and the technique applied to the canine lumbar spine motion segment. Due to the cantilever beam geometry of the cranial articular process, facet joint loads result in surface strains on the lateral aspect of the cranial articular process. Strains were quantified by four strain gages cemented to the bony surface of the process. Strain measured at any one gage depended on the loading site on the articular surface of the caudal facet and on the magnitude of the facet load. Determination of facet loads during in vitro motion segment testing required calibration of the strains to known loads of various magnitudes applied to multiple sites on the caudal facet. The technique is described in detail, including placement of the strain gages. There is good repeatability of strains to applied facet loads and the strains appear independent of load distribution area. Error in the technique depends on the location of the applied facet loads, but is only significant in nonphysiologic locations. The technique was validated by two independent methods in axial torsion. Application of the technique to five in vitro canine L2-3 motion segments testing resulted in facet loads (in newtons, N) of 74+ / -23 N (mean + / -STD) in 2 newton-meter, Nm, extension, to unloaded in flexion. Lateral bending resulted in loads in the right facet of 40+ / -32 N for 1 Nm right lateral bending and 54+ / -29 N for 1 Nm left lateral bending. 4 Nm Torsion with and without 100 N axial compression resulted in facet loads of 92+ / -27 N and 69+ / -19 N, respectively. The technique is applicable to dynamic and in vivo studies. PMID:1762433

  12. A New Technique to Treat Facet Joint Pain With Pulsed Radiofrequency

    PubMed Central

    Schianchi, Pietro Martino

    2015-01-01

    Introduction: Facet joint pain affects 5% to 15% of the population with low back pain and the prevalence increases with age due to progression of arthritis. While conservative treatments are often unsuccessful, the scientific evidence on minimally invasive therapies such as intra-articular steroid infiltration and continuous and pulsed radiofrequency (PRF) of the medial branches is contradictory. Since PRF has recently been reported to successfully treat joint pain, a new application of this method is proposed for facetogenic lumbar pain via an intra-articular subcapsular approach. Here we reported two cases with successful treatment. Case Presentation: A 71-year-old patient presented because of persisting pain in the left gluteal region radiating to the lateral thigh and calf when standing. Anti-inflammatory drugs produced only short-lasting insufficient relief. A 52-year-old employee was admitted in June 2012 because of axial lower lumbar pain with intermittent diffuse radiation to the right lower extremity that worsened during walking and lying down despite receiving analgesics and physiotherapy. Conclusions: A new approach to treat lumbar facet joint pain with PRF is simple to perform and without serious complications. In view of the good long-lasting results obtained with the two reported cases, randomized control trials are necessary to validate this new approach.

  13. Effectiveness of Repeated Radiofrequency Neurotomy for Facet joint Syndrome after Microscopic Discectomy

    PubMed Central

    Kim, Myung Hoon; Kim, Seok Won; Ju, Chang Il; Kim, Dong Min

    2014-01-01

    Objective Postoperative facet joint syndrome requiring radiofrequency neurotomy (RFN) is a relatively common problem following microscopic discectomy. However, the efficacy of repeated RFN after microscopic discectomy has not been clearly documented. The purpose of this study was to determine the success rate and symptom-free duration of repeated RFN for facet joint syndrome after microscopic discectomy. Methods Medical records from 56 patients, who had undergone successful initial RFN following microscopic discectomy, experienced recurrence of pain, and subsequently had repeated RFN, were reviewed and evaluated. Responses of repeated RFN were compared with initial radiofrequency neurotomy for success rates and duration of relief. The criterion for RFN to be successful was defined as greater than 50% relief from pain and sufficient satisfaction of patients with prior RFN to have repeated RFN. Results Fifty-six patients (41 women and 15 men; mean age=48 years) had repeated RFNs, which were successful in all except three patients. RFN denervated three bilateral segments (L3-L4, L4-L5, and L5-S1) in all patients. Mean duration of relief after initial RFN was 9.2 months (range 3-14). The mean duration of relief after secondary RFN in 53 patients was 9.0 months (range 4-14). The success rates and duration of relief remained consistent after subsequent RFNs. Conclusion Repeated RFN for lumbar facet joint pain after microscopic discectomy is an effective palliative treatment. It provided a mean duration of relief of 9.0 months and >94% success rate. PMID:25620983

  14. Septic arthritis of a lumbar facet joint: Detection with bone SPECT imaging

    SciTech Connect

    Swayne, L.C.; Dorsky, S.; Caruana, V.; Kaplan, I.L. (Morristown Memorial Hospital, NJ (USA))

    1989-08-01

    We present a rare case of septic arthritis of a lumbar facet joint with an associated epidural abscess resulting from Staphylococcus aureus. The infection was initially detected with planar bone scintigraphy and precisely localized with single photon emission computed tomography bone scintigraphy, despite an initially negative radiologic evaluation that included radiographs of the lumbar spine, lumbar myelography, and a postmyelography x-ray computed tomography scan. In the appropriate clinical setting, a bone scan demonstrating unilateral increased activity within the spine should raise the suspicion of inflammatory involvement of the posterior elements.

  15. Morphological and biomechanical analyses of the subchondral mineralized zone in human sacral facet joints: Application to improved diagnosis of osteoarthritis.

    PubMed

    Berteau, Jean-Philippe; Mielke, Gabriela; Morlock, Michael M; Huber, Gerd

    2015-05-01

    The anatomy of the facet joint subchondral mineralized zone (SMZ) is the main parameter used in diagnosing osteoarthritis. Usually, a single CT scan slice is used to measure the thickness, but the measurement is highly location-dependent. Bone mineral density (BMD) and porosity could be more reliable than thickness for detecting SMZ sclerosis, and linking them to stiffness can provide insights into the mechanism of osteoarthritis progression. The goal of this study was two-fold: (1) to assess spatial heterogeneity in thickness, BMD, and porosity within the non-pathological human facet joint SMZ; (2) to correlate these measurements with the static modulus of elasticity (MOEsta ). Four non-pathological facet joints were excised and imaged using micro-computed tomography (µCT) to measure SMZ thickness, BMD, and porosity. A total of eight parallelepiped SMZ samples were similarly analyzed and then mechanically tested. The mean SMZ BMD, porosity, and thickness (± Standard Deviation) of the whole facet joints were 611 ± 35 mgHA/cc, 9.8 ± 1.3%, and 1.39 ± 0.41 mm, respectively. The mean BMD, porosity, and MOEsta of the eight SMZ samples were 479 ± 23 mgHA/cc, 12 ± 0.01%, and 387 ± 138 MPa, respectively, with a positive rank correlation between BMD and porosity. BMD and porosity were more homogeneous within the facet joint than thickness and they could be more reliable parameters than thickness for detecting SMZ sclerosis. The values for the physiological SMZ and MOEsta of human facets joints obtained here were independent of BMD. SMZ BMD and porosity were related to each other. Clin. Anat. 28:538-544, 2015. © 2015 Wiley Periodicals, Inc. PMID:25716678

  16. THE PROSTAGLANDIN E2 RECEPTOR, EP2, IS UPREGULATED IN THE DRG AFTER PAINFUL CERVICAL FACET JOINT INJURY IN THE RAT

    PubMed Central

    Kras, Jeffrey V.; Dong, Ling; Winkelstein, Beth A.

    2012-01-01

    Study Design This study implemented immunohistochemistry to assay prostaglandin E2 (PGE2) receptor EP2 expression in the dorsal root ganglion (DRG) of rats after painful cervical facet joint injury. Objective The objective of this study was to identify if inflammatory cascades are induced in association with cervical facet joint distraction-induced pain by investigating the time course of EP2 expression in the DRG. Summary of Background Data The cervical facet joint is a common source of neck pain and non-physiological stretch of the facet capsular ligament can initiate pain from the facet joint via mechanical injury. PGE2 levels are elevated in painful inflamed and arthritic joints, and PGE2 sensitizes joint afferents to mechanical stimulation. Although in vitro studies suggest the EP2 receptor subtype contributes to painful joint disease the EP2 response has not been investigated for any association with painful mechanical joint injury. Methods Separate groups of male Holtzman rats underwent either a painful cervical facet joint distraction injury or sham procedure. Bilateral forepaw mechanical allodynia was assessed, and immunohistochemical techniques were used to quantify EP2 expression in the DRG at days 1 and 7. Results Facet joint distraction induced mechanical allodynia that was significant (p<0.024) at all time points. Painful joint injury also significantly elevated total EP2 expression in the DRG at day 1 (p=0.009), which was maintained also at day 7 (p<0.001). Neuronal expression of EP2 in the DRG was only increased over sham levels at day 1 (p=0.013). Conclusions Painful cervical facet joint distraction induces an immediate and sustained increase of EP2 expression in the DRG, implicating peripheral inflammation in the initiation and maintenance of facet joint pain. The transient increase in neuronal EP2 suggests, as in other painful joint conditions, that after joint injury non-neuronal cells may migrate to the DRG, some of which likely express EP2. PMID:22789984

  17. Percutaneous Procedures for the Diagnosis and Treatment of Lower Back Pain: Diskography, Facet-Joint Injection, and Epidural Injection

    Microsoft Academic Search

    Georges Y. El-Khoury; Donald L. Renfrew

    This review discusses the indications, techniques, complica- tions, and results of three percutaneous procedures used to evaluate and treat lower back pain: diskography, facet-joint injec- tion, and epidural injection. Diskography, performed by injection of contrast medium into the nucleus pulposus, is a technique used to determine the cause of lower back pain in patients in whom findings on other imaging

  18. Diagnostic Value of Lumbar Facet Joint Injection: A Prospective Triple Cross-Over Study

    PubMed Central

    Schütz, Uwe; Cakir, Balkan; Dreinhöfer, Karsten; Richter, Marcus; Koepp, Holger

    2011-01-01

    The diagnosis “lumbar facet syndrome” is common and often indicates severe lumbar spine surgery procedures. It is doubtful whether a painful facet joint (FJ) can be identified by a single FJ block. The aim of this study was to clarify the validity of a single and placebo controlled bilateral FJ blocks using local anesthetics. A prospective single blinded triple cross-over study was performed. 60 patients (31 f, 29 m, mean age 53.2 yrs (22–73)) with chronic low back pain (mean pain persistance 31 months, 6 months of conservative treatment without success) admitted to a local orthopaedic department for surgical or conservative therapy of chronic LBP, were included in the study. Effect on pain reduction (10 point rating scale) was measured. The 60 subjects were divided into six groups with three defined sequences of fluoroscopically guided bilateral monosegmental lumbar FJ test injections in “oblique needle” technique: verum-(local anaesthetic-), placebo-(sodium chloride-) and sham-injection. Carry-over and periodic effects were evaluated and a descriptive and statistical analysis regarding the effectiveness, difference and equality of the FJ injections and the different responses was performed. The results show a high rate of non-response, which documents the lack of reliable and valid predictors for a positive response towards FJ blocks. There was a high rate of placebo reactions noted, including subjects who previously or later reacted positively to verum injections. Equivalence was shown among verum vs. placebo and partly vs. sham also. With regard to test validity criteria, a single intraarticular FJ block with local anesthetics is not useful to detect the pain-responsible FJ and therefore is no valid and reliable diagostic tool to specify indication of lumbar spine surgery. Comparative FJ blocks with local anesthetics and placebo-controls have to be interpretated carefully also, because they solely give no proper diagnosis on FJ being main pain generator. PMID:22140497

  19. Correlation between pseudospondylolisthesis and arthrosis of the hands.

    PubMed

    Muñoz Gómez, J; Brancos Cunill, M A; Rotes Querol, J

    1977-02-01

    Two groups of 25 patients, one with pseudospondylolisthesis (PSL) and the other without, have been compared in order to verify the impression that arthrosis of the hands occurs more frequently in those with PSL. The observed differences were significant, being especially marked in women in whom five or more hand joints were involved and increasing in frequency with age. No relation was found between PSL and either discarthrosis or being overweight. The presence of PSL can probably be included in the pattern of generalized osteoarthrosis described by Kellgren and Lawrence (1958). PMID:847322

  20. [Unilateral hip arthrosis: expression of joint haemochromatosis].

    PubMed

    Prieto Zancudo, C; Villán Villán, Y F; Tascón Guerra, M F

    2012-10-01

    Hereditary haemochromatosis is the most common genetic disorder in the Caucasian population, with an estimated prevalence of 1/200-1/400 (homozygous) and 1/8-1/10 in carriers (heterozygous). The transmission is recessive and linked to HLA. The clinical expression of disease appears only in homozygous and will depend on the time of diagnosis and the degree of organ involvement. The clinical case presented below describes the process of differential diagnosis made in a young patient with unilateral coxarthrosis and clinical suspicion of hemochromatosis. Early diagnosis of hereditary hemochromatosis in primary care can reduce morbidity and mortality of this disease by detecting homozygous at younger ages. PMID:23021581

  1. Incorporation of Lower Neck Shear Forces to Predict Facet Joint Injury Risk in Low-Speed Automotive Rear Impacts

    Microsoft Academic Search

    Brian D. Stemper; Steven G. Storvik

    2010-01-01

    Lower neck shear force remains a viable candidate for a low-velocity automotive rear-impact injury criterion. Data were previously reported to demonstrate high correlations between the magnitude of lower neck shear force and lower cervical spine facet joint motions. The present study determined the ability of lower neck shear force to predict soft-tissue injury risk in simulated automotive rear impacts. Rear-impact

  2. INCREASED INTERLEUKIN-1? & PROSTAGLANDIN E2 EXPRESSION IN THE SPINAL CORD AT 1 DAY AFTER PAINFUL FACET JOINT INJURY: EVIDENCE OF EARLY SPINAL INFLAMMATION

    PubMed Central

    Kras, Jeffrey V.; Dong, Ling; Winkelstein, Beth A.

    2014-01-01

    Study Design This study used immunohistochemistry and an enzyme immunoassay to quantify interleukin-1? (IL-1?) and prostaglanding E2 (PGE2) levels in the spinal cord of rats at one day after painful cervical facet joint injury. Objective The objective of this study was to determine to what extent spinal inflammation is initiated early after a painful loading-induced injury of the C6/C7 facet joint in a rat model. Summary of Background Data A common source of neck pain, the cervical facet joint is susceptible to loading-induced injury, which can lead to persistent pain. IL-1? and PGE2 are associated with joint inflammation and pain, both locally in the joint and centrally in the spinal cord. Joint inflammation has been shown to contribute to pain after facet joint injury. Although spinal neuronal hyperactivity is evident within one day of painful facet injury, it is unknown if inflammatory mediators, such as IL-1? and PGE2, are also induced early after painful injury. Methods Rats underwent either a painful C6/C7 facet joint distraction or sham procedure. Mechanical sensitivity was assessed, and immunohistochemical and enzyme immunoassay techniques were utilized to quantify IL-1? and PGE2 expression in the spinal cord at day 1. Results Both IL-1? and PGE2 were significantly elevated (p?0.04) at day 1 after painful injury. Moreover, although both spinal IL-1? and PGE2 levels were correlated with the withdrawal threshold in response to mechanical stimulation of the forepaw, this correlation was only significant (p=0.01) for PGE2. Conclusions The increased expression of two inflammatory markers in the spinal cord at one day after painful joint injury suggest that spinal inflammation may contribute to the initiation of pain after cervical facet joint injury. Further studies will help identify functional roles of both spinal IL-1? and PGE2 in loading-induced joint pain. PMID:24253784

  3. Effect of changing lumbar stiffness by single facet joint dysfunction on the responsiveness of lumbar muscle spindles to vertebral movement

    PubMed Central

    Reed, William R.; Pickar, Joel G.; Long, Cynthia R.

    2014-01-01

    Objective: Individuals experiencing low back pain often present clinically with intervertebral joint dysfunction. The purpose of this study was to determine whether relative changes in stiffness at a single spinal joint alters neural responsiveness of lumbar muscle spindles to either vertebral movement or position. Methods: Muscle spindle discharge was recorded in response to 1mm L6 ramp and hold movements (0.5mm/s) in the same animal for lumbar laminectomy-only (n=23), laminectomy & L5/6 facet screw (n=19), laminectomy & L5/6 facetectomy (n=5) conditions. Mean instantaneous frequency (MIF) was calculated for the ramp-up, hold, ramp-down and post-ramp phases during each joint condition. Results: Mean MIFs were not significantly different between the laminectomy-only and the other two types of joint dysfunction for the ramp-up, hold, ramp-down, or post-ramp phases. Conclusion: Stiffness changes caused by single facet joint dysfunction failed to alter spindle responses during slow 1mm ramp and hold movements of the L6 vertebra. PMID:24932020

  4. Effects of anterior lumbar spinal fusion on the distribution of nerve endings and mechanoreceptors in the rabbit facet joint: quantitative histological analysis

    Microsoft Academic Search

    Takeshi Onodera; Yasumasa Shirai; Masabumi Miyamoto; Yoshikazu Genbun

    2003-01-01

    The purpose of this study was to investigate the density and distribution of neural endings in rabbit lumbar facet joints after anterior spinal fusion and to evaluate the effects of intervertebral immobilization. An extraperitoneal approach was applied, and L5\\/6 was fixed with a plate and screws. Bilateral L4\\/5, L5\\/6, and L6\\/7 facet joint capsules were harvested from the rabbits 4,

  5. Establishment of a rat model of lumbar facet joint osteoarthritis using intraarticular injection of urinary plasminogen activator.

    PubMed

    Shuang, Feng; Hou, Shu-Xun; Zhu, Jia-Liang; Liu, Yan; Zhou, Ying; Zhang, Chun-Li; Tang, Jia-Guang

    2015-01-01

    Lumbar facet joint (LFJ) osteoarthritis (OA) is an important etiology of low back pain. Several animal models of LFJ OA have been established using intraarticular injection of various chemicals. This study aimed to establish a rat model of LFJ OA using urinary plasminogen activator (uPA). Sprague-Dawley rats were treated with intraarticular injection in the L5-L6 facet joints with uPA (OA group, n = 40) or normal saline (vehicle group, n = 40). Mechanical and thermal hyperalgesia in the ipsilateral hind paws were evaluated using von Frey hairs and a thermoalgesia instrument, respectively. Toluidine blue staining, hematoxylin-eosin staining, and immunohistochemical examination of the LFJ was performed. Treatment with uPA induced cartilage damage, synovitis, and proliferation of synovial cells in the fact joints. The OA group showed significantly higher hyperalgesia in the hind paws in comparison with the vehicle group and normal controls (P < 0.05). Expression of IL-1?, TNF-?, and iNOS in the LFJ cartilage in the OA group was significantly increased (P < 0.05). A rat model of LFJ OA was successfully established using intraarticular injection of uPA. This animal model is convenient and shows good resemblance to human OA pathology. PMID:25892493

  6. Histopathological and ultrastructural modifications of the arthrosis articular cartilage.

    PubMed

    Ciobanu, A; Ciobanu, I R; H?l?l?u, F; Laky, D; Ionescu, T; Dinulescu, I; St?nculescu, D

    1994-01-01

    Thirty samples of articular cartilage taken during the operation from patients with incipient arthrosis, arthrosis with radiological modifications and arthrosis under study for Rheumatoid Arthritis (RA) were investigated using histopathological (HE, VG, PAS-Alcian, Gömöri, Safranine O) and electronmicroscopic techniques. The control material was made of posttraumatic cartilage (Moore prosthesis). Histopathologically, the incipient arthrosis cartilage had superficial exfoliations associated with reduced saframinophilic tinctorial perichondrocytic activity. The arthrosic cartilage with typical radiological modifications was individualized at the synovia-cartilage junction by villous aspects of the synovia associated with perichondrocytic gaps, reduction of safraninophilia and modifications of reticuline-collagenic network. The arthrosic cartilage under study for RA revealed destructive fibrous modifications of the synovia and severe affection of the articular cartilage at synovia-cartilage junction. Electronmicroscopically, the ultrastructural affection was minimum in the incipient arthrosis cartilage developing to chondrocytic degeneration in arthrosis with radiological correspondent. Both histopathological and ultrastructural data emphasize the fact that arthrosis is associated with synovitis following a primitive degenerative process similar to rheumathoid synovitis in arthrosis under study for RA. PMID:7548883

  7. The Prevalence of Lumbar Spine Facet Joint Osteoarthritis and Its Association with Low Back Pain in Selected Korean Populations

    PubMed Central

    Vaccaro, Alexander R.; Lee, Sangwook; Lee, Jaekun; Chang, Hojin

    2014-01-01

    Background This study was to evaluate the association of lumbar spine facet joint osteoarthritis (LSFJOA) identified by multi-detector computed tomography (MDCT) with age and low back pain (LBP) in an adult community-based population in Korea. Methods A sample of 472 participants (age range, 20 to 84 years) who underwent MDCT imaging for abdominal or urological lesions, not for chief complaints of LBP, were included in this study. LSFJOA based on MDCT findings was characterized using four grades of osteoarthritis of the facet joints. The prevalence of LSFJOA according to age group (below 40 years, 40-49 years, 50-59 years, 60-69 years, and above 70 years), gender, and spinal level was analyzed using chi-square tests and the association between LBP and LSFJOA adjusting for age, gender, and spine level was analyzed using multiple binary logistic regression test. Results Eighty-three study subjects (17.58%) had LSFJOA (grade ? 2). The prevalence of LSFJOA was not associated with gender (p = 0.092). The prevalence of LSFJOA increased with age (p = 0.015). The highest prevalence of LSFJOA was observed at L4-5 in men (p = 0.001) and at L5-S1 in women (p = 0.003), and at L5-S1 in the overall population (p = 0.000). LSFJOA was not associated with LBP in men (p = 0.093) but was associated with LBP in women (p = 0.003), especially at L3-4 (p = 0.018) and L5-S1 (p = 0.026). Conclusions The prevalence of LSFJOA based on the computed tomography imaging was 17.58% in the adult community Korean population. The prevalence of LSFJOA increased with age, and the highest prevalence was noted at L5-S1. LSFJOA was not associated with LBP at any spinal level and age except at L3-4 and L5-S1 in women. PMID:25436061

  8. Increased pelvic incidence may lead to arthritis and sagittal orientation of the facet joints at the lower lumbar spine

    PubMed Central

    2013-01-01

    Background Correct sagittal alignment with a balanced pelvis and spine is crucial in the management of spinal disorders. The pelvic incidence (PI) describes the sagittal pelvic alignment and is position-independent. It has barely been investigated on CT scans. Furthermore, no studies have focused on the association between PI and facet joint (FJ) arthritis and orientation. Therefore, our goal was to clarify the remaining issues about PI in regard to (1) physiologic values, (2) age, (3) gender, (4) lumbar lordosis (LL) and (5) FJ arthritis and orientation using CT scans. Methods We retrospectively analyzed CT scans of 620 individuals, with a mean age of 43 years, who presented to our traumatology department and underwent a whole body CT scan, between 2008 and 2010. The PI was determined on sagittal CT planes of the pelvis by measuring the angle between the hip axis to an orthogonal line originating at the center of the superior end plate axis of the first sacral vertebra. We also evaluated LL, FJ arthritis and orientation of the lumbar spine. Results 596 individuals yielded results for (1) PI with a mean of 50.8°. There was no significant difference for PI and (2) age, nor (3) gender. PI was significantly and linearly correlated with (4) LL (p?=?< 0.0001). Interestingly, PI and (5) FJ arthritis displayed a significant and linear correlation (p?=?0.0062) with a cut-off point at 50°. An increased PI was also significantly associated with more sagitally oriented FJs at L5/S1 (p?=?0.01). Conclusion PI is not correlated with age nor gender. However, this is the first report showing that PI is significantly and linearly associated with LL, FJ arthritis and more sagittal FJ orientation at the lower lumbar spine. This may be caused by a higher contact force on the lower lumbar FJs by an increased PI. Once symptomatic or in the event of spinal trauma, patients with increased PI and LL could benefit from corrective surgery and spondylodesis. PMID:24188071

  9. Unusual presentation of giant cell tumor originating from a facet joint of the thoracic spine in a child: a case report and review of the literature

    PubMed Central

    2013-01-01

    Introduction Giant cell tumor of the synovium is a common benign lesion that frequently occurs at the tendon sheaths in the hand; it is usually found in adults over 30 years old. It is related to pigmented villonodular synovitis. Giant cell tumor of the synovium or pigmented villonodular synovitis has been described rarely in the axial skeleton especially in the thoracic vertebrae of a child. Case presentation A previously healthy 7-year-old Thai girl presented with back pain and progressive paraparesis and was unable to walk for 1 month. She had weakness and hyperreflexia of both lower extremities. Magnetic resonance imaging showed a well-defined homogeneously and intensely enhanced extradural mass with cord compression at T4 to T7 levels. The patient underwent laminectomy at T4 through to T7 and total tumor removal. Permanent histopathologic sections and immunostains revealed a giant cell tumor of the synovium. Postoperative neurological status recovered to grade V. Magnetic resonance imaging at the 1-year follow-up showed no recurrence and there was no clinical recurrence at the 2-year follow-up. Conclusion We report an extremely rare case of giant cell tumor in the epidural space that extended from a thoracic facet joint. The tumor was removed successfully through laminectomies. Although giant cell tumor of a facet joint of the thoracic spine is very rare, it must be considered in the differential diagnosis for masses occurring in the epidural space in a child. Total tumor removal is the best treatment. Careful monitoring of recurrence can achieve a good clinical outcome. PMID:23830026

  10. Cervical facet injections in the management of cervicogenic headaches.

    PubMed

    Ng, Andrew; Wang, Dajie

    2015-05-01

    Cervicogenic headache is defined as headaches originating from cervical spine structures including cervical facet joints, cervical intervertebral discs, skeletal muscles, connective tissues, and neurovascular structures. Cervical facet injections with steroids have been used to alleviate cervicogenic headache secondary to cervical facet arthropathy. In this article, we will review the cervical spine anatomy, cervical facet injections, and the efficacy of cervical facet injections as a treatment for cervicogenic headache. PMID:25795156

  11. Facets: Ersatz, Resource and Tag

    ERIC Educational Resources Information Center

    Frické, Martin H.

    2013-01-01

    Introduction: Faceted classification appears to be of utmost importance. Ersatz facets, resource faceting and tag faceting: The distinctions are drawn between facets and ersatz facets, and between faceted resources and faceted tags. Single tag resource faceting and multiple tag information object faceting: The basic features are explored of single…

  12. Calcified cartilage morphometry and its relation to subchondral bone remodeling in equine arthrosis

    Microsoft Academic Search

    R. W Norrdin; C. E Kawcak; B. A Capwell; C. W McIlwraith

    1999-01-01

    The calcified layer of articular cartilage is known to be affected by age and mechanical factors that may play a role in the development of arthrosis. Because these factors are also related to subchondral remodeling and sclerosis, a morphometric study was carried out in fluorochrome-labeled animals to determine whether the level of subchondral remodeling affected the thickness of the calcified

  13. Joints

    NSDL National Science Digital Library

    Olivia Worland (Purdue University; Biological Sciences)

    2008-06-06

    Hinge joints move only in one direction, ball-and-socket joints are free to rotate in all directions, and gliding joints are able to move forward, backward, and side to side, but do not rotate freely.

  14. Controlled medial branch anesthetic block in the diagnosis of chronic lumbar facet joint pain: the value of a three-month follow-up

    PubMed Central

    da Rocha, Ivan Dias; Cristante, Alexandre Fogaça; Marcon, Raphael Martus; Oliveira, Reginaldo Perilo; Letaif, Olavo Biraghi; de Barros Filho, Tarcisio Eloy Pessoa

    2014-01-01

    OBJECTIVES: To verify the incidence of facetary and low back pain after a controlled medial branch anesthetic block in a three-month follow-up and to verify the correlation between the positive results and the demographic variables. METHODS: Patients with chronic lumbar pain underwent a sham blockade (with a saline injection) and then a controlled medial branch block. Their symptoms were evaluated before and after the sham injection and after the real controlled medial branch block; the symptoms were reevaluated after one day and one week, as well as after one, two and three months using the visual analog scale. We searched for an association between the positive results and the demographic characteristics of the patients. RESULTS: A total of 104 controlled medial branch blocks were performed and 54 patients (52%) demonstrated >50% improvements in pain after the blockade. After three months, lumbar pain returned in only 18 individuals, with visual analogue scale scores >4. Therefore, these patients were diagnosed with chronic facet low back pain. The three-months of follow-up after the controlled medial branch block excluded 36 patients (67%) with false positive results. The results of the controlled medial branch block were not correlated to sex, age, pain duration or work disability but were correlated with patient age (p<0.05). CONCLUSION: Patient diagnosis with a controlled medial branch block proved to be effective but was not associated with any demographic variables. A three-month follow-up is required to avoid a high number of false positives. PMID:25141111

  15. [Diclofenac/orphenadrine infusion therapy in patients with active arthrosis].

    PubMed

    Uitz, E; Aglas, F; Wurm, A; Rainer, F

    1998-01-01

    This study investigated the efficacy and safety of a diclofenac/orphenadrin infusion in 21 female and 1 male patients with clinically and radiologically diagnosed inflammatory osteoarthritis of the big joints, especially the knee and hip joints. The patients received 1 infusion per day over 2 h for 10 days. Efficacy and safety were assessed by measuring the subjective pain intensity at rest and during exercise on a visual analogue scale and on an ordinal rating scale before and after every infusion. The patients were interviewed daily for possible side effects. After the 10-days treatment course a 5% reduction of pain at rest and a 37.5% reduction of pain during exercise was observed. Subjective pain intensity was reduced by an average of 32.5%. In most cases relief was noticeable after the 4th infusion. 9 patients rated the medication safety as "very good", 11 patients as "good". A total of 12 patients reported mainly mild side effects such as vertigo, dry mouth, and temporarily reduced visual acuity. Based on its rapid onset of action and its efficacy, it can be stated that the investigated diclofenac/orphenadrin infusion is a valuable extension of the therapeutic methods in patients with inflammatory osteoarthritis. PMID:9700867

  16. Hip arthrosis and surgical intervention: what and when?

    PubMed Central

    Innocenti, Massimo; Nistri, Lorenzo; Biondi, Marco; Del Prete, Armando; Giorgini, Marco; Macera, Armando; Soderi, Stefano

    2013-01-01

    Summary Osteoarthritis of the hip is a common pathology and involves forms of disability and need for treatments that affect the quality of life of patients and their families, and in general of the whole society. It should be considered as such degenerative joint disease is increasing as the increase in life expectancy and musculoskeletal trauma, the latter responsible for secondary forms of osteoarthritis. The treatment of osteoarthritis of the hip has changed a lot over the years, since the earlier diagnosis and, before, with prevention through proper lifestyle. More in-depth knowledge of the biology of the tissues involved, first of all hyaline cartilage, has lead to non-surgical treatments such as infiltration with hyaluronic acid (viscosupplementation) and autologous growth factors derived from platelets (platelet rich plasma). Surgical therapy with prosthetic replacement is finally a choice to share with the patient based on pain and functional limitation, bearing in mind always the best technology and tribology and the possibility of less invasive surgical access, while recognizing that there are not still eternal prosthesis. Of particular importance then is the age of the patient. There are also other types of surgery (hip arthroscopy, forage) for other pathologies of the hip which can be resolutive, or, in a sense, can delay the arrival to the prosthetic replacement. We will discuss below the decision-making process that leads the surgeon with the patient to the surgery option. PMID:23858310

  17. [Arthrosis of the wrist joint due to carpal instability. Therapeutic alternatives].

    PubMed

    Sennwald, G; Kern, H P; Jacob, H A

    1993-02-01

    A kinematic analysis of the movement of the scaphoid, the lunatum and the triquetrum has shown that their turning axes do not correspond with each other. Without arthritis, and within the range of normal motion, the bones move without imposing any appreciable load on the ligaments. They merely guide the bones and hold them together. In the case of arthritic disorders and in states where abnormal frictional resistance occurs, or following trauma, the ligaments are highly loaded. This could lead to increased wear and ruptured ligaments. A series of 20 arthroscopies has shown that LT and SC ligaments are very prone to this, and are often affected simultaneously. Therefore, there may be certain predisposed sites or "weak points", which should definitely not be further aggravated by inappropriate therapeutic measures. The clinician can classify the carpal dysfunction into five main groups; however, the therapy options cannot be classified in the same way. On the basis of clinical experience and the kinematic study, the following statements can be made: scapho-lunatum (SC) arthrodesis can be considered kinematically unsuitable, while scapho-capitatum (SC) and lunato-capitatum (LC) arthrodeses are both clinically and kinematically acceptable. LC arthrodesis has given good results in cases with advanced carpal collapse. From a mechanical point of view, SC arthrodesis is probably better than scapho-trapezo-trapezoid arthrodesis. In the case of ulnar translocation, radio-ulna-to-scaphoid arthrodesis could be an acceptable alternative to total fusion. Proximal row carpectomy can only be a temporary solution, as can prostheses. Partial prostheses, whether of Silastic or titanium, are also not suitable for permanent use.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8451052

  18. SLAC All Access: FACET

    ScienceCinema

    Hogan, Mark

    2014-09-15

    SLAC's Facility for Advanced Accelerator Experimental Tests, or FACET, is a test-bed where researchers are developing the technologies required for particle accelerators of the future. Scientists from all over the world come to explore ways of improving the power and efficiency of the particle accelerators used in basic research, medicine, industry and other areas important to society. In this video, Mark Hogan, head of SLAC's Advanced Accelerator Research Department, offers a glimpse into FACET, which uses part of SLAC's historic two-mile-long linear accelerator.

  19. Facets of Robust Decisions

    Microsoft Academic Search

    Y. Ermoliev; L. Hordijk

    The aim of this paper is to provide an overview of existing concepts of robustness and to identify promising directions for\\u000a coping with uncertainty and risks surrounding on-going global changes. Unlike statistical robustness, general decision problems\\u000a may have rather different facets of robustness. In particular, a key issue is the sensitivity of decisions with respect to\\u000a low-probability catastrophic events. That

  20. FACET Emittance Growth

    SciTech Connect

    Frederico, J; Hogan, M.J.; Nosochkov, Y.; Litos, M.D.; Raubenheimer, T.; /SLAC

    2011-04-05

    FACET, the Facility for Advanced Accelerator and Experimental Tests, is a new facility being constructed in sector 20 of the SLAC linac primarily to study beam driven plasma wakefield acceleration. The FACET beamline consists of a chicane and final focus system to compress the 23 GeV, 3.2 nC electron bunches to {approx}20 {micro}m long and {approx}10 {micro}m wide. Simulations of the FACET beamline indicate the short-duration and large, 1.5% rms energy spread beams may suffer a factor of four emittance growth from a combination of chromaticity, incoherent synchrotron radiation (ISR), and coherent synchrotron radiation (CSR). Emittance growth is directly correlated to head erosion in plasma wakefield acceleration and is a limiting factor in single stage performance. Studies of the geometric, CSR, and ISR components are presented. Numerical calculation of the rms emittance can be overwhelmed by long tails in the simulated phase space distributions; more useful definitions of emittance are given. A complete simulation of the beamline is presented as well, which agrees with design specifications.

  1. Radiographic comparison of a fractured clavicle exhibiting a pseudo-arthrosis.

    PubMed

    Rhode, Matthew P; Goodhue, William W; Stephan, Carl N

    2012-07-01

    Bone remodeling is a natural process that is potentially problematic for radiographic comparisons because it can occur after antemortem (AM) imaging, thus interfering with the comparability of AM and postmortem (PM) radiographs from the same individual. While the effects of age-related remodeling have been studied, limited attention has been given to trauma-related remodeling with respect to radiographic comparisons. This report adds to the latter topic by presenting a case of AM clavicle fracture that developed into a pseudo-arthrosis over a 12-month period prior to the individual's death. Even though remodeling was discernable along the fracture margins, adjacent skeletal features on the PM radiograph remained unaltered and constituted compelling evidence for the identification. This case illustrates the potential of using both normal and pathological anatomy concurrently to maximize the surety of findings from radiographic comparisons. PMID:22409353

  2. End-stage hindfoot arthrosis: outcomes of tibiocalcaneal fusion using internal and Ilizarov fixation.

    PubMed

    Crawford, Brooke; Watson, J Tracy; Jackman, James; Fissel, Brian; Karges, David E

    2014-01-01

    End-stage post-traumatic pantalar arthrosis from ankle, pilon, and talus fractures has often been complicated by infection, bone loss, and a soft tissue deficit. Patients can present with neuropathy, diabetes, tobacco use, and previously failed arthrodesis. Fusion in this population has been challenging, with nonunion rates up to 30%, often leading to amputation. We reviewed the results of a standardized protocol that combined simultaneous internal fixation with the Ilizarov technique to achieve fusion in high-risk patients. With institutional review board approval, a retrospective review of the patients treated with simultaneous internal fixation and an Ilizarov frame was undertaken. The records and radiographs allowed identification of the comorbidities and the presence or absence of successful fusion. Complications were acknowledged and treated. Fifteen patients had undergone the procedure. The mean follow-up period was 27.9 (range 9 to 67) months. Thirteen patients (86.67%) had had previous fusion failure. Twelve patients (80%) had developed post-traumatic arthrosis, 5 (33.33%) of whom had open injuries. All patients had 1 comorbidity, and 10 (66.67%) had multiple, including rheumatoid arthritis, diabetes (types 1 and 2), and smoking. Four patients (26.67%) presented with deep infection and bone loss. Union was achieved in 11 (73.33%), with 12 (80%) patients experiencing profound pain relief. Seven patients (46.67%) required symptomatic hardware removal. Three patients (20%) eventually underwent below-the-knee amputation for recalcitrant nonunion. Statistically significant correlations were found between smoking and wound infection and revision and between nonunion and amputation. Our results have indicated that combined internal fixation with Ilizarov application can provide a strong surgical option for the management of end-stage, pantalar arthritis. More studies are needed to compare the cohort outcomes and gait analysis in these patients with those who have chosen below-the-knee amputation. PMID:24785200

  3. MRI of cervical facet dislocation

    Microsoft Academic Search

    C. C. Leite; B. E. Escobar; J. Randy Jinkins

    1997-01-01

    The MRI examinations of eight patients with cervical vertebral dislocation demonstrated by conventional radiography were\\u000a reviewed. All patients had axial and sagittal T 1- and T 2-weighted imaging on a 1.5-T unit. This revealed unilateral partial\\u000a facet dislocation (in two patients), bilateral partial facet dislocation (in two), unilateral complete dislocation (in two)\\u000a and bilateral complete facet dislocation (in two). In

  4. The clinical aspects of the acute facet syndrome: results from a structured discussion among European chiropractors

    Microsoft Academic Search

    Lise Hestbaek; Alice Kongsted; Tue Secher Jensen; Charlotte Leboeuf-Yde

    2009-01-01

    BACKGROUND: The term 'acute facet syndrome' is widely used and accepted amongst chiropractors, but poorly described in the literature, as most of the present literature relates to chronic facet joint pain. Therefore, research into the degree of consensus on the subject amongst a large group of chiropractic practitioners was seen to be a useful contribution. METHODS: During the annual congress

  5. Anterior cruciate ligament (ACL)-deficient knee with degenerative arthrosis: treatment with an isolated autogenous patellar tendon ACL reconstruction

    Microsoft Academic Search

    K. D. Shelbourne; Keith C. Stube

    1997-01-01

    We evaluated 58 patients (mean age 30.4 years) who had undergone an isolated anterior cruciate ligament (ACL) reconstruction\\u000a for chronic instability (mean time from injury to surgery, 8.2 ± 5.2 years) and showed radiographic evidence of degenerative\\u000a arthrosis. Objective evaluation at a mean of 4.1 years postoperatively included KT-1000 arthrometer stability, range of motion,\\u000a and quadriceps muscle strength testing. Subjective

  6. Backward highlighting: enhancing faceted search

    Microsoft Academic Search

    Max L. Wilson; Paul André; M. C. Schraefel

    2008-01-01

    Directional faceted browsers, such as the popular column browser iTunes, let a person pick an instance from any col- umn-facet to start their search for music. The expected ef- fect is that any columns to the right are filtered. In keeping with this directional filtering from left to right, however, the unexpected effect is that the columns to the left

  7. An anatomical investigation of the human cervical facet capsule, quantifying muscle insertion area

    PubMed Central

    WINKELSTEIN, BETH A.; McLENDON, ROGER E.; BARBIR, ANA; MYERS, BARRY S.

    2001-01-01

    Facet capsule injury has been hypothesised as a mechanism for neck pain. While qualitative studies have demonstrated the proximity of neck muscles to the cervical facet capsule, the magnitude of their forces remains unknown owing to a lack of quantitative muscle geometry. In this study, histological techniques were employed to quantify muscle insertions on the human cervical facet capsule. Computerised image analysis of slides stained with Masson's trichrome was performed to characterise the geometry of the cervical facet capsule and determine the total insertion area of muscle fibres into the facet capsule for the C4–C5 and C5–C6 joints. Muscle insertions were found to cover 22·4±9·6 % of the capsule area for these cervical levels, corresponding to a mean muscle insertion area of 47·6±21·8 mm2. The magnitude of loading to the cervical facet capsule due to eccentric muscle contraction is estimated to be as high as 51 N. When taken in conjunction with the forces acting on the capsular ligament due to vertebral motions, these forces can be as high as 66 N. In that regard, these anatomical data provide quantitative evidence of substantial muscle insertions into the cervical facet capsular ligament and provide a possible mechanism for injury to this ligament and the facet joint as a whole. PMID:11327207

  8. Bony Fusion in a Chronic Cervical Bilateral Facet Dislocation

    PubMed Central

    Bodman, Alexa; Chin, Lawrence

    2015-01-01

    Patient: Male, 60 Final Diagnosis: Bilateral cervical facet dislocation Symptoms: Neck pain Medication: — Clinical Procedure: — Specialty: Neurosurgery Objective: Unusual clinical course Background: Cervical facet dislocation injuries typically present shortly after occurrence due to the pain and neurologic deficit that can be associated with this injury. Bilateral dislocations of the facet joint require prompt evaluation, reduction, and surgical intervention. Rare case reports present bilateral dislocations presenting in a delayed fashion. Case Report: We report the case of a 60-year-old male who presented with mild neck pain 1 year after initial injury. Computed topography of the cervical spine showed healing with bony fusion of a bilateral C6–7 facet dislocation. Given the chronic healed nature of the injury and minimal symptoms, the patient is being followed without intervention. Conclusions: Although most bilateral facet dislocations present and are treated immediately after injury; this case illustrates that some may be missed during initial evaluation. Once healed, these injuries may be stable without surgical intervention. PMID:25702178

  9. L5 – S1 Segmental Kinematics After Facet Arthroplasty

    PubMed Central

    Voronov, Leonard I.; Havey, Robert M.; Rosler, David M.; Sjovold, Simon G.; Rogers, Susan L.; Carandang, Gerard; Ochoa, Jorge A.; Yuan, Hansen; Webb, Scott

    2009-01-01

    Background Facet arthroplasty is a motion restoring procedure. It is normally suggested as an alternative to rigid fixation after destabilizing decompression procedures in the posterior lumbar spine. While previous studies have reported successful results in reproducing normal spine kinematics after facet replacement at L4-5 and L3-4, there are no data on the viability of facet replacement at the lumbosacral joint. The anatomy of posterior elements and the resulting kinematics at L5-S1 are distinctly different from those at superior levels, making the task of facet replacement at the lumbosacral level challenging. This study evaluated the kinematics of facet replacement at L5-S1. Methods Six human cadaveric lumbar spines (L1-S1, 46.7 ± 13.0 years) were tested in the following sequence: (1) intact (L1-S1), (2) complete laminectomy and bilateral facetectomy at L5-S1, and (3) implantation of TFAS-LS (Lumbosacral Total Facet Arthroplasty System, Archus Orthopedics, Redmond, Washington) at L5-S1 using pedicle screws. Specimens were tested in flexion (8Nm), extension (6Nm), lateral bending (LB, ± 6Nm), and axial rotation (AR, ± 5Nm). The level of significance was ? = .017 after Bonferroni correction for three comparisons: (1) intact vs. destabilized, (2) destabilized vs. reconstructed, and (3) intact vs. reconstructed. Results Laminectomy-facetectomy at L5-S1 increased the L5-S1 angular range of motion (ROM) in all directions. Flexion-extension (F-E) ROM increased from 15.3 ± 2.9 to 18.7 ± 3.5 degrees (P < .017), LB from 8.2 ± 1.8 to 9.3 ± 1.6 degrees (P < .017), and AR from 3.7 ± 2.0 to 5.9 ± 1.8 degrees (P < .017). The facet arthroplasty system decreased ROM compared to the laminectomy-facetectomy condition in all tested directions (P < .017). The facet arthroplasty system restored the L5-S1 ROM to its intact levels in LB and AR (P > .017). F-E ROM after the facet arthroplasty system implantation was smaller than the intact value (10.1 ± 2.2 vs. 15.3 ± 2.9 degrees, P < .017). The load-displacement curves after the facet arthroplasty system implantation at L5-S1 were sigmoidal, and quality of motion measures were similar to intact, demonstrating graded resistance to angular motion in F-E, LB and AR. Conclusions The facet arthroplasty system was able to restore stability to the lumbosacral segment after complete laminectomy and bilateral facetectomy, while also allowing near-normal kinematics in all planes. While F-E ROM after the facet arthroplasty system implantation was smaller than the intact value, it was within the physiologic norms for L5-S1. These results are consistent with previous studies of facet arthroplasty at L3-L4 and L4-L5 and demonstrate that TFAS technology can be adapted to the lumbosacral joint with functionality comparable to its application in superior lumbar levels.

  10. Extending Faceted Navigation for RDF Data

    Microsoft Academic Search

    Eyal Oren; Renaud Delbru; Stefan Decker

    2006-01-01

    Data on the Semantic Web is semi-structured and does not follow one fixed schema. Faceted browsing (23) is a natural technique for navigating such data, partitioning the information space into or- thogonal conceptual dimensions. Current faceted interfaces are manu- ally constructed and have limited query expressiveness. We develop an expressive faceted interface for semi-structured data and formally show the improvement

  11. Design of a lattice-based faceted classification system

    NASA Technical Reports Server (NTRS)

    Eichmann, David A.; Atkins, John

    1992-01-01

    We describe a software reuse architecture supporting component retrieval by facet classes. The facets are organized into a lattice of facet sets and facet n-tuples. The query mechanism supports precise retrieval and flexible browsing.

  12. Functional facets for nonlinear crystals

    NASA Astrophysics Data System (ADS)

    Shapira, Asia; Libster, Ana; Lilach, Yigal; Arie, Ady

    2013-07-01

    We report on a new optical device allowing to efficiently add desired functionalities to a nonlinear interaction. This is achieved by focused ion beam patterning of a nano-layer of gold sputtered at the exit facet of a nonlinear crystal. The functionality is experimentally demonstrated with three examples: spatial filtering where a fundamental beam with a poor mode quality and its' frequency-doubled beam are filtered thereby providing high mode quality beams, focusing of a generated second harmonic beam and beam shaping where a fundamental Gaussian beam is transformed into any arbitrary desired frequency-doubled beam. For the latter two examples, the functional facet also provides angular separation of the fundamental and second harmonic beams.

  13. Morphological Stability of Faceted Interfaces

    NASA Technical Reports Server (NTRS)

    Abbaschian, Reza; Golyshev, V. D.; Gonik, M.; Tsvetivsky, V.; deVahlDavis, G.; Leonardi, E.

    2001-01-01

    The major focus of this investigation is to study the fundamentals of layer spreading mechanisms during growth of doped Ge (a facet forming material), and to determine the conditions for morphological instability of vicinal solid-liquid interfaces. The investigation will also lead to the determination of the effect of dopants on the layer growth kinetics, step free energy, and dopant capture by the advancing ledges. The theoretical treatment of growth of faceted interfaces indicates that the kinetics of a step on a growing vicinal interface considerably depends on its angle of inclination, the melt concentration, and characteristics of flow currents in the melt. The morphological stability of the interface also depends on these parameters, as well as on the density and spreading velocity of the steps. However, the treatment of the instability of the interface by the layer growth mechanism is rather difficult because it requires exact knowledge of the thermal and solutal fields, hydrodynamics of the melt, and supercooling at the interface. The results of recent space experiments of the principal investigator involving directional solidification of faceted Bi-Sn alloys have shown that the morphological stability of various crystallographic orientations is significantly affected by the anistropy in interfacial properties of the faceted alloy in general, and the interface kinetics in particular. These findings have also raised many important and fundamental questions, particularly with respect to the behavior of interfacial steps, which need to be addressed via additional groundbased and microgravity experiments. For the present investigation we will use a novel crystal growth technique which provides axial heat flux close to the solid-liquid boundary. The Axial Heat Processing (AHP) technique allows for precise control and determination of the heat and mass transfer close to the crystallization front, and the establishment of a planar interface over the entire cross-section of the growing crystal.

  14. Gabapentin alleviates facet-mediated pain in the rat through reduced neuronal hyperexcitability and astrocytic activation in the spinal cord

    PubMed Central

    Dong, Ling; Crosby, Nathan D.; Winkelstein, Beth A.

    2013-01-01

    Although joint pain is common, its mechanism(s) remain undefined, with little known about the spinal neuronal responses that contribute to this type of pain. Afferent activity and sustained spinal neuronal hyperexcitability correlate to facet joint loading and the extent of behavioral sensitivity induced after painful facet injury, suggesting spinal neuronal plasticity is induced in association with facet-mediated pain. This study used a rat model of painful C6/C7 facet joint stretch, together with intrathecal administration of gabapentin, to investigate the effects of one aspect of spinal neuronal function on joint pain. Gabapentin or saline vehicle was given via lumbar puncture prior to and at 1 day after painful joint distraction. Mechanical hyperalgesia was measured in the forepaw for 7 days. Extracellular recordings of neuronal activity and astrocytic and microglial activation in the cervical spinal cord were evaluated at day 7. Gabapentin significantly (p=0.0001) attenuated mechanical hyperalgesia and the frequency of evoked neuronal firing also significantly decreased (p<0.047) with gabapentin treatment. Gabapentin also decreased (p<0.04) spinal GFAP expression. Although spinal Iba1 expression was doubled over sham, gabapentin did not reduce it. Facet joint-mediated pain appears to be sustained through spinal neuronal modifications that are also associated with astrocytic activation. PMID:24094695

  15. Kinematics of total facet replacement (TFAS-TL) with total disc replacement

    PubMed Central

    Voronov, Leonard I.; Havey, Robert M.; Sjovold, Simon G.; Funk, Michael; Carandang, Gerard; Zindrick, Daniel; Rosler, David M.; Patwardhan, Avinash G.

    2009-01-01

    Background Total disc replacement (TDR) and total facet replacement (TFR) have been the focus of recent kinematics evaluations. Yet their concurrent function as a total joint replacement of the lumbar spine's 3-joint complex has not been comprehensively reported. This study evaluated the effect of a TFR specifically designed to replace the natural facets and supplement the function with the natural disc and with TDR. The ability to replace degenerated facets to complement a pre-existing or simultaneously implanted TDR may allow surgeons to completely address degenerative pathologies of the 3-joint complex of the lumbar spine. We hypothesized that TFR would reproduce the biomechanical function of the natural facets when implanted in conjunction with TDR. Methods Lumbar spines (L1-5, 51.3 ± 14.2 years, N = 6) were tested sequentially as follows: (1) intact, (2) after TDR implantation, and (3) after TFR implantation in conjunction with TDR, all at L3-4. Specimens were tested in flexion-extension (+ 8 Nm to ? 6 Nm), lateral bending (± 6 Nm), and axial rotation (± 5 Nm). A 400 N compressive follower preload was applied during flexion-extension tests. Three-dimensional segmental motion was recorded and analyzed using analysis of variance in Systat (Systat Software Inc., Chicago, Illinois) and multiple comparisons with Bonferroni correction. Results The TDR implantation (TDR + natural facets) allowed similar lateral bending (P = .66), but it generally increased flexion-extension (P = .06) and axial rotation (P < .05) range of motion (ROM) at the implanted level compared to intact. The TFR + TDR (following replacement of the natural facets with TFR) decreased ROM to levels similar to intact in lateral bending (P = .70) and axial rotation (P = .23). The TFR + TDR flexion-extension ROM was reduced in comparison to intact and TDR + natural facets (P < .05). Conclusions The TFR with TDR was able to restore stability to the lumbar segment after bilateral facetectomy, while allowing near-normal motions in all planes.

  16. Pathogenesis aspects of arthrosis in histopathological and electronmicroscopical studies of articular cartilage, correlated to some immunological parameters.

    PubMed

    Ciobanu, A; Ciobanu, I R; H?l?l?u, F; Laky, D; Ionescu, T; Popescu, M; Dinulescu, I; St?nculescu, D

    1994-01-01

    Twenty-five biopsies of arthrosic cartilage with radiological correspondence, arthro, sic cartilage under study for Rheumatoid Arthritis (RA) and posttrauma cartilage as control-were examined using histopathological (HE, VG, PAS-Alcian, Gömöri, Safranine O) and electronmicroscopical techniques. The arthrosic cartilage with radiological correspondence shows superficial and deep fissures, perichondrocytic gaps and modified reticulino-collagenic network at the histopathological examination. At the level of synovia-cartilage junction, we found some villous aspects of the synovia desquamating in the proximity of the affected cartilage. The investigated arthroses for RA presented some destructive fibrous modifications of the synovia similar to rheumatoid synovitis and associated with some dystrophic chondrocytic alterations. The ultrastructural affection was severe leading to cellular degeneration. The immunologically-studied arthroses for RA had seric pathologic values regarding: circulating immune complexes (CIC) (mean = 67.08 +/- 1.45 U), Ig.M(mean = 358 +/- 3.02 UI/ml) and anti collagen antibodies (mean = 409.9 +/- 0.42 U). The synovial depletion of complementary fraction C3(mean = 42.3-1 mg%) as against the normal seric level (mean = 63.07 +/- 0.49 mg%) suggests an immune synovitis. Correlation of immunomorphopathological data emphasize that arthrosis coexists with a secondary synovitis following a primitive degenerative process and allows arthroses under study for RA to be separated from other degenerative rheumatism diseases. PMID:7548882

  17. New developments in facet design and analysis

    Microsoft Academic Search

    Uriel G. Foa

    1965-01-01

    In multivariate research design the systematic definition of the set of variables in terms of more basic sets, the facets, leads to the prediction of the empirical interrelationship among the variables. 2 principles are suggested for predicting the results from the facet structure of the variables: the principle of contiguity and the semantic principal components. The principle of contiguity simply

  18. [Conservative surgery in Kienbock's disease with perilunate arthrosis: articular resurfacing using resected carpal bones].

    PubMed

    Salon, A; Hémon, C

    2003-06-01

    We present 2 cases of Kienböck's disease in which peri-lunate chondral lesions contra-indicated classical procedures such as proximal row carpectomy or 4 corner arthrodesis. A partial carpectomy provided us with an osteochondral graft, used to resurface the areas of chondral damage over the capitate or on the radius. The clinical and radiological result was stable at a follow-up of 3 and 6 years. In the first case, degenerative changes over the head of the capitate contra-indicated proximal row carpectomy. The lunate was removed and the proximal 2/3 of the scaphoid were shifted medially and fused in a "four-corner"-like arthrodesis. In the second case, the lunate fossa on the radius was damaged. The proximal row was excised and an osteochondral graft was harvested from the triquetrum. This was used to replace the lunate fossa on the radius. This new concept of a "carpal bank" has enabled us to extend the classical indications for proximal row carpectomy and four-corner arthrodesis. It makes it possible to withdraw the limits of conservative wrist surgery in Kienböck's disease and we believe this concept could also be extended to similar situations of localized chondral damage in small joints. PMID:12889271

  19. FACET: SLAC___s New User Facility

    SciTech Connect

    Clarke, C.I.; Decker, F.-J.; England, R.J.; Erickson, R.A.; Hast, C.; Hogan, M.J.; Li, S.Z.; Litos, M.D.; Nosochkov, Y.; Seeman, J.T.; Sheppard, J.; Wienands, U.; Woodley, M.; Yocky, G.; /SLAC

    2012-05-16

    FACET (Facility for Advanced Accelerator Experimental Tests) is a new User Facility at SLAC National Accelerator Laboratory. The first User Run started in spring 2012 with 20 GeV, 3 nC electron beams. The facility is designed to provide short (20 {micro}m) bunches and small (20 {micro}m wide) spot sizes, producing uniquely high power beams. FACET supports studies from many fields but in particular those of Plasma Wakefield Acceleration and Dielectric Wakefield Acceleration. The creation of drive and witness bunches and shaped bunch profiles is possible with 'Notch' Collimation. FACET is also a source of THz radiation for material studies. Positrons will be available at FACET in future user runs. We present the User Facility and the available tools and opportunities for future experiments.

  20. Posterior Epidural Migration of an Extruded Lumbar Disc Mimicking a Facet Cyst: A Case Report

    PubMed Central

    Yoo, Young Sun; Ju, Chang Il; Kim, Dong Min

    2015-01-01

    Dorsal extradural migration of extruded disc material is clinically uncommon. We report a rare case of posterior epidural migration of an extruded lumbar disc mimicking a facet cyst. A 32-year-old man was admitted to our institute with a 2-week history of severe low back pain and radiating pain in the left leg. The magnetic resonance (MR) images revealed a dorsally located, left-sided extradural cystic mass at the L2-3 level. The initial diagnosis was an epidural facet cyst because of the high signal intensity on MR images and its location adjacent to the facet joint. Intraoperatively, an encapsulated mass of soft tissue adherent to the dural sac was observed and excised. The pathological diagnosis was degenerated disc material. After surgery, the patient experienced complete relief from leg pain.

  1. Finite-element evaluation of contact loads on facets of an L2-L3 lumbar segment in complex loads.

    PubMed

    Shirazi-Adl, A

    1991-05-01

    In this study, the contact loads and regions on facets of a lumbar motion segment are quantitatively determined. The analysis accounts for both material and geometric nonlinearities and treats the facet articulation as a frictionless, nonlinear, moving contact problem. The loadings consist of axial torque and lateral bending acting alone or in combination with axial compression force. Complex loadings simulating symmetric and nonsymmetric liftings are also considered. Under identical magnitude of rotation, axial torque generates the largest contact forces, followed by extension, flexion, and lateral bending. Contact forces under loads simulating heavy symmetric lifting are as, or even larger than, those under large extension and axial torque loadings. The presence of axial and lateral rotations during forward flexion significantly increases the loads transmitted through the compression facet. The tension facet, in this case, became nearly unloaded. The large loads on the facets, predicted especially under nonsymmetric, combined flexion loadings, are likely to play a role in the observed disorders of the facet joints. Under various loadings, the transfer of forces from one facet to the adjacent one occurs through three distinct areas, namely, extension-type, flexion-type, and torsion-type contact areas. The relative magnitude of different components of the transmitted forces are also predicted to vary considerably, depending on these regions of contact. PMID:2052996

  2. Facet development for a faceted stretched-membrane dish by Solar Kinetics, Inc

    SciTech Connect

    Schertz, P.T.; Brown, D.C.; Konnerth, A. III (Solar Kinetics, Inc., Dallas, TX (United States)) [Solar Kinetics, Inc., Dallas, TX (United States)

    1991-07-01

    A 3.6-meter diameter stretched-membrane optical facet for a parabolic dish has been successfully designed and demonstrated under contract with Sandia National Laboratories. Twelve facets identical to them will be used to make the lightweight reflector of the dish. The project goal of 2.5-mrad surface accuracy was met with each of the two full-sized prototypes, and accuracies of as low as 1.1 mrad were achieved. The facet weight is 11.7 kg/m{sup 2} (2.4lbs/ft{sup 2}). The facet is similar in construction to the successful stretched-membrane heliostat; it has two thin metal membranes attached to a ring. However, the front membrane for this facet is plastically formed at the factor in order to achieve a shorter facet f/D (approximately 3.0). A passive tether restrains the from membrane when not in operation, that is, when the stabilizing vacuum is off. The optical surface is achieved with a silvered-acrylic film laminated to the metal membrane. The facet is expected to cost $55.40/m{sup 2} at a production rate of 10,000 facets per year and $115, 000/m{sup 2}-at a production rate of 500 facets a year. Several key issues have been resolved. Stress concentrations due to seams in the reflective laminate did not cause membrane rupture during forming as they have for dishes with lower focal length-to-diameter ratios. The laminate survived the forming process and simulated operation without deterioration. The optical effect of the tether on the membrane was tested and found to be very small. Most important, highly accurate shapes were obtained using a simple forming procedure. Additional tests are needed to demonstrate process repeatablility and facet performance in typical operating conditions. 18 refs., 36 figs., 11 tabs.

  3. Laser ionized preformed plasma at FACET

    NASA Astrophysics Data System (ADS)

    Green, S. Z.; Adli, E.; Clarke, C. I.; Corde, S.; Edstrom, S. A.; Fisher, A. S.; Frederico, J.; Frisch, J. C.; Gessner, S.; Gilevich, S.; Hering, P.; Hogan, M. J.; Jobe, R. K.; Litos, M.; May, J. E.; Walz, D. R.; Yakimenko, V.; Clayton, C. E.; Joshi, C.; Marsh, K. A.; Vafaei-Najafabadi, N.; Muggli, P.

    2014-08-01

    The Facility for Advanced Accelerator and Experimental Tests (FACET) at SLAC installed a 10-TW Ti?:?sapphire laser system for pre-ionized plasma wakefield acceleration experiments. High energy (500 mJ), short (50 fs) pulses of 800 nm laser light at 1 Hz are used at the FACET experimental area to produce a plasma column. The laser pulses are stretched to 250 fs before injection into a vapor cell, where the laser is focused by an axicon lens to form a plasma column that can be sustained over the desired radius and length. A 20 GeV electron bunch interacts with this preformed plasma to generate a non-linear wakefield, thus accelerating a trailing witness bunch with gradients on the order of several GV m-1. The experimental setup and the methods for producing the pre-ionized plasma for plasma wakefield acceleration experiments performed at FACET are described.

  4. The acoustical characteristics of the normal and abnormal temporomandibular joint.

    PubMed

    Gay, T; Bertolami, C N; Donoff, R B; Keith, D A; Kelly, J P

    1987-05-01

    This paper describes the results of a clinical study that recorded and analyzed sounds emitted from the temporomandibular joint (TMJ) during simple function as a means for differentially diagnosing disorders of the joint. The technique is based on the principle that each different disorder of the TMJ produces a different effect on the mechanical relationship between the articulating surfaces of the joint, and that these mechanical effects can be determined by analyzing joint sounds in relation to joint movement. A total of 79 patients (101 joints) were studied; 32 (46 joints) were diagnosed as having extracapsular disorders, (primarily MPD), 27 (32 joints) were diagnosed as having a displaced disc with reduction, nine (10 joints) were diagnosed as having a displaced disc without reduction, and 11 (13 joints) were diagnosed as degenerative disease (osteoarthritis/arthrosis). In addition, 25 adults (50 joints) with normal TMJs were included as controls. The results of this study demonstrated that each specific disease of the TMJ is characterized by a unique relationship between the sounds propagated by the joint and the movement of the joint. Essentially, an extracapsular disease was characterized by acoustic quiescence during natural (as opposed to maximal) jaw movement, an internal derangement by a usually symmetrical short duration click/reciprocal click, or random click complex, depending on the subcategory of the disorder, and a degenerative disease by a long duration noise during either or both jaw opening and closing. The data further suggest that the technique serves to reflect the mechanical events (and abnormalities) that are involved in function of the diseased joint and has potential for use as a clinical diagnostic tool. PMID:3471925

  5. Problem of time: facets and Machian strategy.

    PubMed

    Anderson, Edward

    2014-10-01

    The problem of time is that "time" in each of ordinary quantum theory and general relativity are mutually incompatible notions. This causes difficulties in trying to put these two theories together to form a theory of quantum gravity. The problem of time has eight facets in canonical approaches. I clarify that all but one of these facets already occur at the classical level, and reconceptualize and re-name some of these facets as follows. The frozen formalism problem becomes temporal relationalism, the thin sandwich problem becomes configurational relationalism, via the notion of best matching. The problem of observables becomes the problem of beables, and the functional evolution problem becomes the constraint closure problem. I also outline how each of the global and multiple-choice problems of time have their own plurality of facets. This article additionally contains a local resolution to the problem of time at the conceptual level and which is actually realizable for the relational triangle and minisuperspace models. This resolution is, moreover, Machian, and has three levels: classical, semiclassical, and a combined semiclassical-histories-timeless records scheme. I end by delineating the current frontiers of this program toward resolution of the problem of time in the cases of full general relativity and of slightly inhomogeneous cosmology. PMID:25266113

  6. Multiple facets of macrophages in renal injury

    Microsoft Academic Search

    DAVID C KLUTH; LARS-PETER ERWIG; ANDREW J REES

    2004-01-01

    Multiple facets of macrophages in renal injury.Macrophage infiltration is a common feature of renal disease and their presence has been synonymous with tissue damage and progressive renal failure. More recently work has focused on the heterogeneity of macrophage activation and in particular their ability to curtail inflammation and restore normal function. This has led to the view that it is

  7. Problem of Time: Facets and Machian Strategy

    E-print Network

    Edward Anderson

    2014-07-15

    The Problem of Time is that `time' in each of ordinary quantum theory and general relativity are mutually incompatible notions. This causes difficulties in trying to put these two theories together to form a theory of Quantum Gravity. The Problem of Time has 8 facets in canonical approaches. I clarify that all but one of these facets already occur at the classical level, and reconceptualize and re-name some of these facets as follows.The Frozen Formalism Problem becomes Temporal Relationalism, the Thin Sandwich Problem becomes Configurational Relationalism, via the notion of Best Matching. The Problem of Observables becomes the Problem of Beables, and the Functional Evolution Problem becomes the Constraint Closure Problem. I also outline how each of the Global and Multiple-Choice Problems of Time have their own plurality of facets. This article additionally contains a local resolution to the Problem of Time at the conceptual level and which is actually realizable for the relational triangle and minisuperspace models. This resolution is, moreover, Machian, and has three levels: classical, semiclassical and a combined semiclassical-histories-timeless records scheme. I end by delineating the current frontiers of this program toward resolution of the Problem of Time in the cases of full GR and of slightly inhomogeneous cosmology.

  8. Bone scans are reliable for the identification of lumbar disk and facet pathology.

    PubMed

    Malham, Gregory M; Parker, Rhiannon M; Ballok, Zita E; Goss, Ben; Diwan, Ashish D; Uribe, Juan S

    2015-02-01

    Study Design?Surgeon survey. Objective?To evaluate the reliability of bone single-photon emission computed tomography (SPECT) versus bone SPECT images co-registered with computed tomography (bone SPECT-CT) by analyzing interobserver agreement for identification of the anatomical location of technetium(99m)-labeled oxidronate uptake in the lumbar disk and/or facet joint. Methods?Seven spine surgeons interpreted 20 bone scans: 10 conventional black-and-white tomograms (bone SPECT) and 10 color-graded bone SPECT-CT scans. Each surgeon was asked to identify the location of any diagnostically relevant uptake in the disk and/or facet joint between L1 and S1. Reliability was evaluated using the free-marginal kappa statistic, and the level of agreement was assessed using the Landis and Koch interpretation. Results?Conventional bone SPECT scans and bone SPECT-CT scans were reliable for the identification of diagnostically relevant uptake, with bone SPECT-CT having higher reliability (kappa?=?0.72) than bone SPECT alone (0.59). Bone SPECT and bone SPECT-CT were also reliable in identifying disk pathology, with kappa values of 0.72 and 0.81, respectively. However, bone SPECT-CT was more reliable (0.81) than bone SPECT (0.60) when identifying facet disease. Conclusions?For the identification of disk pathology, it is reasonable to use either conventional bone SPECT or bone SPECT-CT; however, bone SPECT-CT is more reliable for facet joint pathology. PMID:25648168

  9. Bone Scans Are Reliable for the Identification of Lumbar Disk and Facet Pathology

    PubMed Central

    Malham, Gregory M.; Parker, Rhiannon M.; Ballok, Zita E.; Goss, Ben; Diwan, Ashish D.; Uribe, Juan S.

    2014-01-01

    Study Design?Surgeon survey. Objective?To evaluate the reliability of bone single-photon emission computed tomography (SPECT) versus bone SPECT images co-registered with computed tomography (bone SPECT-CT) by analyzing interobserver agreement for identification of the anatomical location of technetium99m-labeled oxidronate uptake in the lumbar disk and/or facet joint. Methods?Seven spine surgeons interpreted 20 bone scans: 10 conventional black-and-white tomograms (bone SPECT) and 10 color-graded bone SPECT-CT scans. Each surgeon was asked to identify the location of any diagnostically relevant uptake in the disk and/or facet joint between L1 and S1. Reliability was evaluated using the free-marginal kappa statistic, and the level of agreement was assessed using the Landis and Koch interpretation. Results?Conventional bone SPECT scans and bone SPECT-CT scans were reliable for the identification of diagnostically relevant uptake, with bone SPECT-CT having higher reliability (kappa?=?0.72) than bone SPECT alone (0.59). Bone SPECT and bone SPECT-CT were also reliable in identifying disk pathology, with kappa values of 0.72 and 0.81, respectively. However, bone SPECT-CT was more reliable (0.81) than bone SPECT (0.60) when identifying facet disease. Conclusions?For the identification of disk pathology, it is reasonable to use either conventional bone SPECT or bone SPECT-CT; however, bone SPECT-CT is more reliable for facet joint pathology. PMID:25648168

  10. Facets for Discovery and Exploration in Text Collections

    SciTech Connect

    Rose, Stuart J.; Roberts, Ian E.; Cramer, Nicholas O.

    2011-10-24

    Faceted classifications of text collections provide a useful means of partitioning documents into related groups, however traditional approaches of faceting text collections rely on comprehensive analysis of the subject area or annotated general attributes. In this paper we show the application of basic principles for facet analysis to the development of computational methods for facet classification of text collections. Integration with a visual analytics system is described with summaries of user experiences.

  11. Discriminant Validity of NEO-PIR Facet Scales

    Microsoft Academic Search

    Robert R. McCrae; Paul T. Costa

    1992-01-01

    Two analyses were conducted to examine the discriminant validity of 30 facet scales from the Revised NEO Personality Inventory (NEO-PIR). To examine cross-observer validity of specific variance in the facet scales, partial correlations between self-reports and peer (N = 250) and spouse (N = 68) ratings on the facets were calculated, controlling for the five common factors. All 60 convergent

  12. FACET: The New User Facility at SLAC

    SciTech Connect

    Clarke, C.I.; Decker, F.J.; Erikson, R.; Hast, C.; Hogan, M.J.; Iverson, R.; Li, S.Z.; Nosochkov, Y.; Phinney, N.; Sheppard, J.; Wienands, U.; Woodley, M.; Yocky, G.; /SLAC; Seryi, A.; /Oxford U., JAI; Wittmer, W.; /Michigan State U.

    2011-12-13

    FACET (Facility for Advanced Accelerator and Experimental Tests) is a new User Facility at SLAC National Accelerator Laboratory. Its high power electron and positron beams make it a unique facility, ideal for beam-driven Plasma Wakefield Acceleration studies. The first 2 km of the SLAC linac produce 23 GeV, 3.2 nC electron and positron beams with short bunch lengths of 20 {mu}m. A final focusing system can produce beam spots 10 {mu}m wide. User-aided Commissioning took place in summer 2011 and FACET will formally come online in early 2012. We present the User Facility, the current features, planned upgrades and the opportunities for further experiments. Accelerators are our primary tool for discovering the fundamental laws to the universe. Each new frontier we probe requires a new, more powerful method. Accelerators are therefore increasing in size and cost. The future of this field requires new accelerating techniques that can reach the high energies required over shorter distances. New concepts for high gradient acceleration include utilizing the wakes in plasma and dielectric and metallic structures. FACET was built to provide a test bed for novel accelerating concepts with its high charge and highly compressed beams. As a test facility unlike any other, it has also attracted groups interested in beam diagnostic techniques and terahertz studies. The first phase of the construction was completed in May 2011. Beam commissioning began in June and was interleaved with the installation of five experiments. Users were invited to aid with the commissioning for the month of August during which time experimental hardware and software were checked out and some first measurements were taken. FACET is currently in the process of becoming a Department of Energy User Facility for High Energy Physics.

  13. Thrombospondin-4 and excitatory synaptogenesis promote spinal sensitization after painful mechanical joint injury.

    PubMed

    Crosby, Nathan D; Zaucke, Frank; Kras, Jeffrey V; Dong, Ling; Luo, Z David; Winkelstein, Beth A

    2015-02-01

    Facet joint injury induces persistent pain that may be maintained by structural plasticity in the spinal cord. Astrocyte-derived thrombospondins, especially thrombospondin-4 (TSP4), have been implicated in synaptogenesis and spinal sensitization in neuropathic pain, but the TSP4 response and its relationship to synaptic changes in the spinal cord have not been investigated for painful joint injury. This study investigates the role of TSP4 in the development and maintenance of persistent pain following injurious facet joint distraction in rats and tests the hypothesis that excitatory synaptogenesis contributes to such pain. Painful facet joint loading induces dorsal horn excitatory synaptogenesis along with decreased TSP4 in the DRG and increased astrocytic release of TSP4 in the spinal cord, all of which parallel the time course of sustained tactile allodynia. Blocking injury-induced spinal TSP4 expression with antisense oligonucleotides or reducing TSP4 activity at its neuronal receptor in the spinal cord with gabapentin treatment both attenuate the allodynia and dorsal horn synaptogenesis that develop after painful facet joint loading. Increased spinal TSP4 also facilitates the development of allodynia and spinal hyperexcitability, even after non-painful physiological loading of the facet joint. These results suggest that spinal TSP4 plays an important role in the development and maintenance of persistent joint-mediated pain by inducing excitatory synaptogenesis and facilitating the transduction of mechanical loading of the facet joint that leads to spinal hyperexcitability. PMID:25483397

  14. Roughness metrics of prismatic facets of ice

    NASA Astrophysics Data System (ADS)

    Neshyba, S. P.; Lowen, B.; Benning, M.; Lawson, A.; Rowe, P. M.

    2013-04-01

    We define a surface normal roughness metric for mesoscopically rough ice facets and present methods for inferring its value from variable pressure scanning electron micrographs. The methods rely on the anisotropic morphology of roughening in the prismatic plane, in which nearly all the variation in surface height occurs in the direction of the main symmetry axis of hexagonal-habit ice prisms. Because of this symmetry, roughening appears at boundaries between prismatic facets in a way that readily permits quantitative analysis. Prismatic surfaces of four ice crystals grown between -45 and -30°C are found to have mean surface normal roughness values of 0.04-0.1, a range that corresponds to Cox-Munk roughness scale parameters 0.3-0.5. The distribution of tilt angles also suggests a Weibull shape parameter smaller than unity, a result that compares favorably with field observations. Shortwave scattering calculations of hexagonal polyhedra with surface morphologies derived from these observations indicate substantial retention of the well-known 22° halo, despite a large (4-6%) reduction in the asymmetry parameter compared to smooth-surface counterparts. We argue that this signature is a generic outcome of the symmetry of the roughening, which in turn originates in the anisotropic surface self-diffusivity of these facets.

  15. High Stability of Faceted Nanotubes and Fullerenes of Multiphase Layered Phosphorus: A Computational Study

    NASA Astrophysics Data System (ADS)

    Guan, Jie; Zhu, Zhen; Tománek, David

    2014-11-01

    We present a paradigm in constructing very stable, faceted nanotube and fullerene structures by laterally joining nanoribbons or patches of different planar phosphorene phases. Our ab initio density functional calculations indicate that these phases may form very stable, nonplanar joints. Unlike fullerenes and nanotubes obtained by deforming a single-phase planar monolayer at substantial energy penalty, we find faceted fullerenes and nanotubes to be nearly as stable as the planar single-phase monolayers. The resulting rich variety of polymorphs allows us to tune the electronic properties of phosphorene nanotubes and fullerenes not only by the chiral index but also by the combination of different phosphorene phases. In selected phosphorene nanotubes, a metal-insulator transition may be induced by strain or by changing the number of walls.

  16. Interventional radiology in bone and joint

    SciTech Connect

    Bard, M.; Laredo, J.D.

    1988-01-01

    Recent radiologic procedures in bone and joints, some of which eliminate the need for surgery are exposed, including: trephine biopsies of the thoracic and lumbar spine, sacro-iliac joints, peripheral bones synovial membrane and soft tissues, using either fluoroscopic echographic or CT guidance - chemonucleolysis - vascular embolization of skeletal tumors and management of vertebral hemangiomas - selective steroid injection in a broad spectrum of diseases including vertebral facet syndrome, cervicobrachial nerve root pain, rotator cuff calcium deposit, bone cysts.

  17. Fabrication of faceted nanopores in magnesium

    SciTech Connect

    Wu, Shujing; Cao, Fan; Zheng, He; Sheng, Huaping; Liu, Chun; Liu, Yu; Zhao, Dongshan; Wang, Jianbo, E-mail: wang@whu.edu.cn [School of Physics and Technology, Center for Electron Microscopy and MOE Key Laboratory of Artificial Micro- and Nano-Structures, Wuhan University, Wuhan 430072 (China)] [School of Physics and Technology, Center for Electron Microscopy and MOE Key Laboratory of Artificial Micro- and Nano-Structures, Wuhan University, Wuhan 430072 (China)

    2013-12-09

    In this paper, using high resolution transmission electron microscopy, we showed the fabrication of faceted nanopores with various shapes in magnesium by focused electron beam (e-beam). The characteristics of nanopore shapes and the crystallographic planes corresponding to the edges of the nanopores were discussed in detail. Interestingly, by manipulating the e-beam (e.g., irradiation direction and duration), the nanopore shape and size could be effectively controlled along different directions. Our results provide important insight into the nanopore patterning in metallic materials and are of fundamental importance concerning the relevant applications, such as nanopore-based sensor, etc.

  18. Prezygapophyseal articular facet shape in the catarrhine thoracolumbar vertebral column.

    PubMed

    Russo, Gabrielle A

    2010-08-01

    Two contrasting patterns of lumbar vertebral morphology generally characterize anthropoids. "Long-backed" monkeys are distinguished from "short-backed" apes [Benton: The baboon in medical research, Vol. 2 (1967:201)] with respect to several vertebral features thought to afford greater spinal flexibility in the former and spinal rigidity in the latter. Yet, discussions of spinal mobility are lacking important functional insight that can be gained by analysis of the zygapophyses, the spine's synovial joints responsible for allowing and resisting intervertebral movements. Here, prezygapophyseal articular facet (PAF) shape in the thoracolumbar spine of Papio, Hylobates, Pongo, Gorilla, and Pan is evaluated in the context of the "long-backed" versus "short-backed" model. A three-dimensional geometric morphometric approach is used to examine how PAF shape changes along the thoracolumbar vertebral column of each taxon and how PAF shape varies across taxa at corresponding vertebral levels. The thoracolumbar transition in PAF shape differs between Papio and the hominoids, between Hylobates and the great apes, and to a lesser extent, among great apes. At the level of the first lumbar vertebra, the PAF shape of Papio is distinguished from that of hominoids. At the level of the second lumbar vertebra, there is variation to some extent among all taxa. These findings suggest that morphological and functional distinctions in primate vertebral anatomy may be more complex than suggested by a "long-backed" versus "short-backed" dichotomy. PMID:20310062

  19. An Integrated Facet-Based Library for Arbitrary Software Components

    NASA Astrophysics Data System (ADS)

    Schmidt, Matthias; Polowinski, Jan; Johannes, Jendrik; Fernández, Miguel A.

    Reuse is an important means of reducing costs and effort during the development of complex software systems. A major challenge is to find suitable components in a large library with reasonable effort. This becomes even harder in today's development practice where a variety of artefacts such as models and documents play an equally important role as source code. Thus, different types of heterogeneous components exist and require consideration in a component search process. One flexible approach to structure (software component) libraries is faceted classification. Faceted classifications and in particular faceted browsing are nowadays widely used in online systems. This paper takes a fresh approach towards using faceted classification in heterogeneous software component libraries by transferring faceted browsing concepts from the web to software component libraries. It presents an architecture and implementation of such a library. This implementation is used to evaluate the applicability of facets in the context of an industry-driven case study.

  20. Preliminary design of large reflectors with flat facets

    NASA Technical Reports Server (NTRS)

    Agrawal, P. K.; Anderson, M. S.; Card, M. F.

    1980-01-01

    A concept for approximating curved antenna surfaces using flat facets is discussed. A preliminary design technique for determining the size of the reflector surface facets necessary to meet antenna surface accuracy requirements is presented. A proposed large Microwave Radiometer Satellite is selected as an application, and the far field electromagnetic response of a faceted reflector surface is compared with that from a spherical reflector surface.

  1. On the facets of the simple plant location packing polytope

    Microsoft Academic Search

    Lázaro Cánovas; Mercedes Landete; Alfredo Mar??n

    2002-01-01

    We introduce new classes of facet-defining inequalities for the polytope Ppd associated with the set packing formulation of the simple plant location problem (SPLP) with p plants and d destinations. The inequalities are obtained by identifying subgraphs of the intersection graph G(p,d) of SPLP that are facet-defining, and lifting their associated facets if it is necessary. To this end, we

  2. Faceted ceramic fibers, tapes or ribbons and epitaxial devices therefrom

    DOEpatents

    Goyal, Amit

    2013-07-09

    A crystalline article includes a single-crystal ceramic fiber, tape or ribbon. The fiber, tape or ribbon has at least one crystallographic facet along its length, which is generally at least one meter long. In the case of sapphire, the facets are R-plane, M-plane, C-plane or A-plane facets. Epitaxial articles, including superconducting articles, can be formed on the fiber, tape or ribbon.

  3. Faceted ceramic fibers, tapes or ribbons and epitaxial devices therefrom

    SciTech Connect

    Goyal, Amit (Knoxville, TN)

    2012-07-24

    A crystalline article includes a single-crystal ceramic fiber, tape or ribbon. The fiber, tape or ribbon has at least one crystallographic facet along its length, which is generally at least one meter long. In the case of sapphire, the facets are R-plane, M-plane, C-plane or A-plane facets. Epitaxial articles, including superconducting articles, can be formed on the fiber, tape or ribbon.

  4. Faceted needle crystals: an analytical approach Mokhtar

    NASA Astrophysics Data System (ADS)

    Adda-Bedia; Hakim, Vincent

    1994-03-01

    Faceted dendrites have been observed in some crystal growth experiments. It has previously been proposed that these diffusion-limitéd growing shapes obey the classical equations of dendritic growth with modified boundary conditions on the interface. We analyse this new set of equations when capillary effects are neglected on the rough parts. In this limit, we find that it is not possible to require both a tangential matching of the rough and faceted parts and the saine melting temperature on the front and trailing rough interface. An exact solution is obtained when one of these physical constraints is relaxed. The conséquences of this result for the full problem are considered and an approximate solution is proposed. Des dendrites facettées ont été observées dans quelques expériences de croissance cristalline. Il a été antérieurement proposé de décrire ces nouvelles formes de croissance limitée par la diffusion au moyen des équations classiques de la croissance dendritique en utilisant des conditions aux limites modifiées sur l'interface. Nous analysons ce nouvel ensemble d'équations en négligeant la tension de surface sur les parties rugueuses. Dans cette limite, nous trouvons qu'il n'est pas possible d'imposer à la fois un raccord tangentiel des parties rugueuses et facettées et de maintenir les interfaces rugueuses avant et arrière à la même temperature de fusion. Une solution exacte est obtenue en relâchant une de ces conditions physiques. Nous discutons les conséquences de ce résultat pour le problème complet et une solution approchée en est proposée.

  5. Psychopathy and instrumental violence: facet level relationships.

    PubMed

    Walsh, Zach; Swogger, Marc T; Kosson, David S

    2009-08-01

    The relationship between psychopathy and violence is well established. However, the extent to which psychopathy is related to different types of violent behavior warrants further study. We examined the relationship between instrumental violence, psychopathy, and psychopathic traits among 248 European American and African American adult male county jail inmates. We assessed instrumentality based on subjective motivations for respondent-identified acts of violence. Psychopathy was assessed using the PCL-R based on interview and file review. We controlled for potentially important covariates, namely IQ and prior violence. Results were in part consistent with findings from studies with adolescents, in that we identified a positive relationship between instrumentality of violence and manipulative interpersonal style. Results differed from youth studies with regard to relationships between instrumentality and other facets of psychopathy. The implications of our study are discussed with regard to treatment and the developmental stability of the relationship between psychopathic traits and instrumental violence. PMID:19663661

  6. FACET Tolerances for Static and Dynamic Misalignments

    SciTech Connect

    Federico, Joel

    2012-07-13

    The Facility for AdvancedAccelerator and Experimental Tests (FACET) at the SLAC National Accelerator Laboratory is designed to deliver a beam with a transverse spot size on the order of 10 {micro}m x 10 {micro}m in a new beamline constructed at the two kilometer point of the SLAC linac. Commissioning the beamline requires mitigating alignment errors and their effects, which can be significant and result in spot sizes orders of magnitude larger. Sextupole and quadrupole alignment errors in particular can introduce errors in focusing, steering, and dispersion which can result in spot size growth, beta mismatch, and waist movement. Alignment errors due to static misalignments, mechanical jitter, energy jitter, and other physical processes can be analyzed to determine the level of accuracy and precision that the beamline requires. It is important to recognize these effects and their tolerances in order to deliver a beam as designed.

  7. Mamillo-accessory notch and foramen: distribution patterns and correlation with superior lumbar facet structure.

    PubMed

    Mahato, N K

    2014-12-01

    The mamillary (MP) and the accessory (AP) processes are two important anatomical landmarks in the lumbar vertebral morphology. These two processes form the mamillo-accessory notch (MAN) between them. In the living, the MP and the AP are connected together by the mamillo-accessory ligament (MAL). The medial branches of lumbar dorsal rami pass underneath the MAL. The MAL often undergoes varied degrees of ossification with diverse notching at the junction of these two processes, often with formation of a discrete foramen (MAF). Reports on the distribution of these notches (MAN) and foramina (MAF) are very few and most of them do not discuss such ossification in context of morphology of adjoining structures in the vertebrae. Lumbar vertebral and sacral specimens were screened for three different categories of narrowing at the mamillo-accessory junction: firstly >1/2 notch, secondly ¾ notch, and thirdly MAF and their distribution patterns were mapped along the lumbar spine. Transverse dimensions of superior facet articulating surfaces [length (a)] and widths of MPs [length (b)] were recorded. Relative widths of the MPs were calculated as index M (a/b). Results suggest associations between the degrees of assimilation of the MPs into the facet joints, the index M values, and the different types of mamillo-accessory junctional anatomy. This study may help to understand if MAN and MAF related dorsal rami entrapment neuropathies arise merely due to osteoarthritic ossification of the MAL or could also be accounted for by facet dimensions or degree of MP-facet fusions that abut close to the mamillo-accessory junctions. PMID:24889272

  8. Search Interface Design Using Faceted Indexing for Web Resources.

    ERIC Educational Resources Information Center

    Devadason, Francis; Intaraksa, Neelawat; Patamawongjariya, Pornprapa; Desai, Kavita

    2001-01-01

    Describes an experimental system designed to organize and provide access to Web documents using a faceted pre-coordinate indexing system based on the Deep Structure Indexing System (DSIS) derived from POPSI (Postulate based Permuted Subject Indexing) of Bhattacharyya, and the facet analysis and chain indexing system of Ranganathan. (AEF)

  9. Facet Stability in Oxygen-Induced Nanofaceting of

    E-print Network

    Facet Stability in Oxygen-Induced Nanofaceting of Re(123¯1) Hao Wang, Ally S. Y. Chan,,§ Wenhua of metal surfaces focus mainly on body-centered cubic or face-centered cubic metals, such as W(111),1,2 Mo- agonal close-packed (hcp) metal, little is known about its faceting behavior although it is an important

  10. Faceted grating prism for a computed tomographic imaging spectrometer

    E-print Network

    Dereniak, Eustace L.

    Faceted grating prism for a computed tomographic imaging spectrometer Michael W. Kudenov Julia://opticalengineering.spiedigitallibrary.org/ on 02/04/2013 Terms of Use: http://spiedl.org/terms #12;Faceted grating prism for a computed tomographic disperser based on a 2-D grating prism and a division of aperture approach. Included is an optical design

  11. Two Facets of Competitiveness and Their Influence on Psychological Adjustment

    Microsoft Academic Search

    ElaineKayhan

    2003-01-01

    This study was conducted to explore the influence of competitiveness as a personality trait on psychological adjustment. Competitiveness was differentiated into two distinct facets referred to as superiority competitiveness and mastery competitiveness. In terms of psychological adjustment, the effects of these facets of competitiveness on depression, loneliness, self-esteem, anxiety, and eating patterns were examined. Questionnaires were used to assess the

  12. Platinum nanocrystals selectively shaped using facet-specific peptide sequences

    NASA Astrophysics Data System (ADS)

    Chiu, Chin-Yi; Li, Yujing; Ruan, Lingyan; Ye, Xingchen; Murray, Christopher B.; Huang, Yu

    2011-05-01

    The properties of a nanocrystal are heavily influenced by its shape. Shape control of a colloidal nanocrystal is believed to be a kinetic process, with high-energy facets growing faster then vanishing, leading to nanocrystals enclosed by low-energy facets. Identifying a surfactant that can specifically bind to a particular crystal facet is critical, but has proved challenging to date. Biomolecules have exquisite specific molecular recognition properties that can be explored for the precise engineering of nanostructured materials. Here, we report the use of facet-specific peptide sequences as regulating agents for the predictable synthesis of platinum nanocrystals with selectively exposed crystal surfaces and particular shapes. The formation of platinum nanocubes and nanotetrahedrons are demonstrated with Pt-{100} and Pt-{111} binding peptides, respectively. Our studies unambiguously demonstrate the abilities of facet-selective binding peptides in determining nanocrystal shape, representing a critical step forward in the use of biomolecules for programmable synthesis of nanostructures.

  13. Hip joints

    NSDL National Science Digital Library

    Connie Raab (National Institutes of Health; )

    2006-05-17

    The human hips are an example of a ball-and-socket joint. Ball-and-socket joints have the ability to rotate in a circular motion. The joint where the arm connects to the shoulder is also a type of ball-and-socket joint.

  14. Knee joint transplantation combined with surgical angiogenesis in rabbits – a new experimental model

    PubMed Central

    Kremer, Thomas; Giusti, Guilherme; Friedrich, Patricia F.; Willems, Wouter; Bishop, Allen T.; Giessler, Goetz A.

    2012-01-01

    Summary Purpose We have previously described a means to maintain bone allotransplant viability, without long-term immune modulation, replacing allogenic bone vasculature with autogenous vessels. A rabbit model for whole knee joint transplantation was developed and tested using the same methodology, initially as an autotransplant. Materials/Methods Eight New Zealand White rabbit knee joints were elevated on a popliteal vessel pedicle to evaluate limb viability in a non-survival study. Ten additional joints were elevated and replaced orthotopically in a fashion identical to allotransplantation, obviating only microsurgical repairs and immunosuppression. A superficial inferior epigastric facial (SIEF) flap and a saphenous arteriovenous (AV) bundle were introduced into the femur and tibia respectively, generating a neoangiogenic bone circulation. In allogenic transplantation, this step maintains viability after cessation of immunosuppression. Sixteen weeks later, x-rays, microangiography, histology, histomorphometry and biomechanical analysis were performed. Results Limb viability was preserved in the initial 8 animals. Both soft tissue and bone healing occurred in 10 orthotopic transplants. Surgical angiogenesis from the SIEF flap and AV bundle was always present. Bone and joint viability was maintained, with demonstrable new bone formation. Bone strength was less than the opposite side. Arthrosis and joint contractures were frequent. Conclusion We have developed a rabbit knee joint model and evaluation methods suitable for subsequent studies of whole joint allotransplantation. PMID:22113889

  15. Hydrothermal growth of multi-facet anatase spheres

    NASA Astrophysics Data System (ADS)

    Wu, Jin-Ming; Song, Xiao-Mei; Ma, Lu-Yao; Wei, Xiao-Dan

    2011-03-01

    Titania with various nanostructures can be synthesized by several F --mediated procedures. In this paper, we report the synthesis of a novel multi-facet microsphere consisting of etched single-crystalline anatase by simply immersing metallic Ti plates in an HF aqueous solution under hydrothermal conditions. The etched multi-facet sphere was found to grow through the nucleation and growth of truncated bipyramids on a previously precipitated one to assemble a microsphere, and its subsequent etching by HF to expose the thermodynamic stable {1 0 1} facets. The photocatalytic activity of such etched multi-facet sphere thin films was evaluated utilizing rhodamine B and sulfonic salicylic acid in water as target molecules and compared with commercial Degussa P25 titania nanoparticles.

  16. Cervical Facet Arthropathy and Occipital Neuralgia: Headache Culprits

    Microsoft Academic Search

    J. D. Hoppenfeld

    2010-01-01

    Cervicogenic headache (CH) is pain referred from the neck. Two common causes are cervical facet arthropathy and occipital\\u000a neuralgia. Clinical diagnosis is difficult because of the overlying features between primary headaches such as migraine, tension-type\\u000a headache, and CH. Interventional pain physicians have focused on supporting the clinical diagnosis of CH with confirmatory\\u000a blocks. The treatment of cervical facet arthropathy as

  17. Framework Application for Core Edge Transport Simulation (FACETS)

    SciTech Connect

    Dr. Allen D. Malony; Dr. Sameer S. Shende; Dr. Kevin A. Huck; Mr. Alan Morris, and Mr. Wyatt Spear

    2012-03-14

    The goal of the FACETS project (Framework Application for Core-Edge Transport Simulations) was to provide a multiphysics, parallel framework application (FACETS) that will enable whole-device modeling for the U.S. fusion program, to provide the modeling infrastructure needed for ITER, the next step fusion confinement device. Through use of modern computational methods, including component technology and object oriented design, FACETS is able to switch from one model to another for a given aspect of the physics in a flexible manner. This enables use of simplified models for rapid turnaround or high-fidelity models that can take advantage of the largest supercomputer hardware. FACETS does so in a heterogeneous parallel context, where different parts of the application execute in parallel by utilizing task farming, domain decomposition, and/or pipelining as needed and applicable. ParaTools, Inc. was tasked with supporting the performance analysis and tuning of the FACETS components and framework in order to achieve the parallel scaling goals of the project. The TAU Performance System�������������������������������® was used for instrumentation, measurement, archiving, and profile / tracing analysis. ParaTools, Inc. also assisted in FACETS performance engineering efforts. Through the use of the TAU Performance System, ParaTools provided instrumentation, measurement, analysis and archival support for the FACETS project. Performance optimization of key components has yielded significant performance speedups. TAU was integrated into the FACETS build for both the full coupled application and the UEDGE component. The performance database provided archival storage of the performance regression testing data generated by the project, and helped to track improvements in the software development.

  18. Mean-field theory for coarsening faceted surfaces.

    PubMed

    Norris, Scott A; Watson, Stephen J

    2012-02-01

    A mean-field theory is developed for the scale-invariant length distributions observed during the coarsening of generic one-dimensional faceted surfaces. This theory closely follows the Lifshitz-Slyozov-Wagner theory of Ostwald ripening in two-phase systems, but the mechanism of coarsening in faceted surfaces requires the addition of convolution terms recalling work on particle coalescence, and induces an unexpected coupling between the convolution and the rate of facet loss. As a generic framework, the theory concisely illustrates how the universal processes of facet removal and neighbor merger are moderated by the system-specific mean-field velocity describing average rates of length change. For a simple, example facet dynamics associated with the directional solidification of a binary alloy, agreement between the predicted scaling state and that observed after direct numerical simulation of 40,000,000 facets is reasonable given the limiting assumption of noncorrelation between neighbors; relaxing this assumption is a clear path forward toward improved quantitative agreement with data in the future. PMID:22463224

  19. Structural Equation Modelling of Multiple Facet Data: Extending Models for Multitrait-Multimethod Data

    ERIC Educational Resources Information Center

    Bechger, Timo M.; Maris, Gunter

    2004-01-01

    This paper is about the structural equation modelling of quantitative measures that are obtained from a multiple facet design. A facet is simply a set consisting of a finite number of elements. It is assumed that measures are obtained by combining each element of each facet. Methods and traits are two such facets, and a multitrait-multimethod…

  20. Beyond Text Queries and Ranked Lists: Faceted Search in Library Catalogs

    ERIC Educational Resources Information Center

    Niu, Xi

    2012-01-01

    Since the adoption of faceted search in a small number of academic libraries in 2006, faceted library catalogs have gained popularity in many academic and public libraries. This dissertation seeks to understand whether faceted search improves the interactions between searchers and library catalogs and to understand ways that facets are used in…

  1. Linguistic Facets for Genre and Text Type Identification: A Description of Linguistically-Motivated Features

    Microsoft Academic Search

    Marina Santini

    In this report we propose a new set of features for automatic genre and text type identification: linguistic facets. The label linguistic facet has been created to stress the fact that each of the features in this new set highlights a facet, i.e. an aspect in the communicative context that is reflected in the use of language. Linguistic facets subsume

  2. High-Index Facets in Gold Nanocrystals Elucidated by Coherent Electron Diffraction

    PubMed Central

    Shah, Amish B.; Sivapalan, Sean T.; DeVetter, Brent M.; Yang, Timothy K.; Wen, Jianguo; Bhargava, Rohit; Murphy, Catherine J.; Zuo, Jian-Min

    2013-01-01

    Characterization of high index facets in noble metal nanocrystals for plasmonics and catalysis has been a challenge due to their small sizes and complex shapes. Here, we present an approach to determine the high index facets of nanocrystals using streaked Bragg reflections in coherent electron diffraction patterns, and provide a comparison of high index facets on unusual nanostructures such as trisoctahedra. We report new high index facets in trisoctahedra and previous unappreciated diversity in facet sharpness. PMID:23484620

  3. Surgical treatment of Rockwood grade-V acromioclavicular joint dislocations

    PubMed Central

    2013-01-01

    Background and purpose Long-term outcome after surgery for grade-V acromioclavicular joint dislocation has not been reported. We performed a retrospective analysis of functional and radiographic outcome 15–22 years after surgery. Patients and methods We examined 50 patients who were treated at our hospital between April 1985 and December 1993. Various methods of stabilization were used: K-wires (n = 36), 4.5-mm screw (n = 12), or biodegradable screw (n = 2). Osteosynthesis material was removed after 6–8 weeks. Mean follow-up time was 18 (15–22) years. Outcomes were assessed with the Constant shoulder (CS) score, Disabilities of the Arm, Shoulder, and Hand (DASH) score, the simple shoulder test (SST), the Copeland shoulder impingement test, the cross-arm test, pain, stability of the AC joint, and complications. From radiographs, we evaluated AC and glenohumeral (GH) arthrosis, osteolysis of the lateral clavicle, and alignment of the clavicle with the acromion. Results Mean values were 90 (75–100) in CS score, 5.1 (0–41) in DASH score, and 11 (2–12) in SST. There was no statistically significant difference in CS score between the injured shoulder and the uninjured shoulder. The AC joint was clinically stable in 42 patients. In 38 patients, the clavicle alignment with the acromion was normal in radiographs. Lateral clavicle osteolysis (10 patients) appeared to be associated with permanent AC joint dislocation. Interpretation Surgery with a temporary fixation for acute grade-V AC joint dislocation leads to successful long-term functional results. Only minor disability occurred in some patients. PMID:23409813

  4. Lumbar degenerative disc disease and tibiotalar joint arthritis: a 710-specimen postmortem study.

    PubMed

    Boiwka, Alex V; Bajwa, Navkirat S; Toy, Jason O; Eubanks, Jason; Ahn, Nicholas U

    2015-04-01

    Research has associated lumbar spinal disease with lower extremity arthrosis. These studies focused solely on the lumbar spine's connection with hip or knee pathology, failing to investigate potential ankle relationships. We specifically explored the interplay between lumbar disc degeneration and tibiotalar joint arthritis. Lumbar disc degeneration and tibiotalar joint arthritis was graded 0 to 4, according to osteophytosis of the vertebral rim and talar surface in 710 randomly selected cadaveric specimens. We corrected for confounding factors of age, sex, race, and height. A significant association was found between lumbar disc degeneration and tibiotalar joint arthritis (P < .01). Lumbar disc degeneration encompassing 3 intervetebral discs demonstrated the highest odds for development of severe tibiotalar joint arthritis. Severe lumbar degenerative disc disease was more prevalent than severe tibiotalar joint arthritis in individuals age 20 years and older. Furthermore, the presence of severe lumbar degeneration significantly predisposes individuals to the development of severe ankle arthritis (P < .05). Gait changes resulting from disc degeneration or neural compression in the lumbar spine may play a role in ankle osteoarthritis development. This association must be considered when treating patients with lumbar disc degeneration and leg pain. PMID:25844591

  5. Reduction of rms-error in shallow faceted large space antennas

    NASA Technical Reports Server (NTRS)

    Fichter, W. B.

    1983-01-01

    This paper examines the potential for reducing root-mean-square surface error in shallow faceted reflectors by replacing flat facets with membrane facets. Exact solutions are obtained for the small lateral deflections of equilateral triangular and rectangular membranes subject to isotropic tension and parabolic edge deflections. These solutions are used to minimize the rms-error between a facet of a shallow paraboloidal surface and its approximating membrane facet. The resulting optimum placements and edge curvatures yield membrane facets which have significantly lower rms-errors than the corresponding best-fit flat facets. The rms-error reductions are about 55 percent for equilateral triangles and 25 percent to 93 percent for rectangles, depending on aspect ratio. The results suggest that the use of membrane facets conforming to curved structural members could yield reflectors with lower rms-error, or comparable error with larger facets and, hence, fewer structural members.

  6. Mapping mindfulness facets onto dimensions of anxiety and depression.

    PubMed

    Desrosiers, Alethea; Klemanski, David H; Nolen-Hoeksema, Susan

    2013-09-01

    Mindfulness has been associated with anxiety and depression, but the ways in which specific facets of mindfulness relate to symptoms of anxiety and depression remains unclear. The purpose of the current study was to investigate associations between specific facets of mindfulness (e.g., observing, describing, nonjudging, acting with awareness, and nonreactivity) and dimensions of anxiety and depression symptoms (e.g., anxious arousal, general distress-anxiety, general distress-depression, and anhedonic depression) while controlling for shared variance among variables. Participants were 187 treatment-seeking adults. Mindfulness was measured using the Five Facet Mindfulness Questionnaire and symptoms of depression and anxiety were measured using the Mood and Anxiety Symptom Questionnaire. Bivariate correlations showed that all facets of mindfulness were significantly related to all dimensions of anxiety and depression, with two exceptions: describing was unrelated to general distress-anxiety, and observing was unrelated to all symptom clusters. Path analysis was used to simultaneously examine associations between mindfulness facets and depression and anxiety symptoms. Significant and marginally significant pathways were retained to construct a more parsimonious model and model fit indices were examined. The parsimonious model indicated that nonreactivity was significantly inversely associated with general distress anxiety symptoms. Describing was significantly inversely associated with anxious arousal, while observing was significantly positively associated with it. Nonjudging and nonreactivity were significantly inversely related to general distress-depression and anhedonic depression symptomatology. Acting with awareness was not significantly associated with any dimensions of anxiety or depression. Findings support associations between specific facets of mindfulness and dimensions of anxiety and depression and highlight the potential utility of targeting these specific aspects of mindfulness in interventions for anxiety and mood disorders. PMID:23768665

  7. Development of an improved mirror facet for space applications

    NASA Technical Reports Server (NTRS)

    Schertz, Paul; Saifee, Shabbar; Lammert, Luke

    1991-01-01

    A fabrication technique was successfully developed for a metallic aluminum honeycomb, high-accuracy, lightweight, and long-life solar concentrator (mirror) for Advanced Solar Dynamic Space Power Systems. The program scope was limited to the development, fabrication, evaluation, and delivery of a solar concentrator facet (petal) that was sized for a 2-meter deployable solar concentrator. A surface accuracy of 1.0 mrad was achieved. The development incorporated tooling design, material selection, facet forming, adhesive selection, testing, and analysis. Techniques for applying levelizing, reflective, and protective optical coatings were also developed.

  8. CONSTRUCTIVE AND DESTRUCTIVE FACETS OF WEIL DESCENT ON ELLIPTIC CURVES

    E-print Network

    Gaudry, Pierrick

    , divisor class group, cryptography, elliptic curves. 1 #12; 2 P. GAUDRY, F. HESS, AND N.P. SMART We shallCONSTRUCTIVE AND DESTRUCTIVE FACETS OF WEIL DESCENT ON ELLIPTIC CURVES P. GAUDRY, F. HESS, AND N and Smart for producing curves in the Weil restriction of an elliptic curve over a finite field

  9. CONSTRUCTIVE AND DESTRUCTIVE FACETS OF WEIL DESCENT ON ELLIPTIC CURVES

    E-print Network

    Hess, Florian

    , divisor class group, cryptography, elliptic curves. 1 #12;2 P. GAUDRY, F. HESS, AND N.P. SMART We shallCONSTRUCTIVE AND DESTRUCTIVE FACETS OF WEIL DESCENT ON ELLIPTIC CURVES P. GAUDRY, F. HESS, AND N and Smart for producing curves in the Weil restriction of an elliptic curve over a finite field

  10. Exploratory Patent Search with Faceted Search and Configurable Entity Mining

    E-print Network

    Tzitzikas, Yannis

    Exploratory Patent Search with Faceted Search and Configurable Entity Mining Pavlos Fafalios1 Searching for patents is usually a recall-oriented problem and depending on the patent search type, quite. We propose an exploratory strategy for patent search that exploits the metadata already available

  11. Beyond Conflict: Functional Facets of the Work-Family Interplay

    ERIC Educational Resources Information Center

    Wiese, Bettina S.; Seiger, Christine P.; Schmid, Christian M.; Freund, Alexandra M.

    2010-01-01

    The present paper deals with three positive facets of the work-family interplay, i.e., transfer of competencies, transfer of positive mood, and cross-domain compensation. The latter refers to the experience that engagement in one domain helps dealing with failures in the other domain. In two correlational studies (N[subscript 1] = 107 working…

  12. Facet: Streaming over Videoconferencing for Censorship Circumvention University of Minnesota

    E-print Network

    Minnesota, University of

    Facet: Streaming over Videoconferencing for Censorship Circumvention Shuai Li University Keywords censorship resistance, video conferencing, traffic analysis 1. INTRODUCTION As the Internet has to the tools designed to circumvent this censorship, such as Tor [13] and other proxy services. These tools

  13. On vector quantization for fast facet edge detection

    Microsoft Academic Search

    M. Y. Jaisimha; Jill R. Goldschneider; Alexander E. Mohr; Eve A. Riskin; Robert M. Haralick

    1994-01-01

    Presents an approach for performing edge detection which builds on prior work in fast facet edge detection using tree-structured vector quantization (TSVQ). The authors first extend the approach by using larger image vectors to reduce computational complexity by performing edge detection on multiple pixels at once. They then reduce the computational complexity of the edge detector without sacrificing performance by

  14. MULTI-FACETED SUSTAINABILITY ON ITHACA COLLEGE NATURAL LANDS

    EPA Science Inventory

    This student-generated proposal presents a multi-faceted program for sustainable stewardship of the natural areas south of the built campus of Ithaca College. Our challenge is to use student research and class projects to enhance biodiversity, support education and research, and...

  15. Conceptualizing Educational Leadership: Does Exploring Macro-Level Facets Matters?

    ERIC Educational Resources Information Center

    Sinha, Chetan

    2013-01-01

    The present review attempts to examine the present status of educational leadership highlighting the role of macro-level facets in Asian Pacific context. The conceptualization of educational leadership among researchers so far had been found to vary according to different contexts and situations. Theoretical perspectives associated with…

  16. Pervasive Social Computing: Augmenting Five Facets of Human Intelligence

    Microsoft Academic Search

    Jiehan Zhou; Junzhao Sun; Kumaripaba Athukorala; Dinesh Wijekoon

    2010-01-01

    Pervasive Social Computing is a novel collective paradigm, derived from pervasive computing, social media, social networking, social signal processing, etc. This paper reviews Pervasive Social Computing as an integrated computing environment, which promises to augment five facets of human intelligence in physical environment awareness, behavior awareness, community awareness, interaction awareness, and content awareness. Reviews of related studies are given and

  17. Examining Student Rating of Teaching Effectiveness Using FACETS

    ERIC Educational Resources Information Center

    Mat Daud, Nuraihan; Abu Kassim, Noor Lide

    2011-01-01

    Students' evaluations of teaching staff can be considered high-stakes, as they are often used to determine promotion, reappointment, and merit pay to academics. Using Facets, the reliability and validity of one student rating questionnaire is analysed. A total of 13,940 respondents of the Human Science Division of International Islamic University…

  18. Interactive Retrieval Based on Faceted Feedback Lanbo Zhang, Yi Zhang

    E-print Network

    Zhang, Yi

    search interface in e-commerce, this paper investigates interactive relevance feedback mechanism based results show that the Boolean filtering approach, which is widely used in faceted search in e-commerce search has gained great success in e-commerce domain over the past years, and most popular online retail

  19. Personality Facets and RIASEC Interests: An Integrated Model

    ERIC Educational Resources Information Center

    Armstrong, Patrick Ian; Anthoney, Sarah Fetter

    2009-01-01

    Research examining links between personality and interest have typically focused on links between measures of the five factor model and Holland's RIASEC types. However, the five factor model of personality can be divided in to a larger set of narrow domain personality scales measuring facets of the "big five" traits. Research in a number of fields…

  20. Depression in the work of British health visitors: Clinical facets

    Microsoft Academic Search

    Michael Sheppard

    1996-01-01

    The primary health care setting has been established as a key venue for identifying and working with depression. Despite this, and the high risk of depression experienced by women in the post-natal period, maternal depression has been little examined in the work of health visitors. This study focuses on clinical facets of this work, including the rate and content of

  1. Terahertz Light Source and User Area at FACET

    SciTech Connect

    Wu, Z.; Li, S.Z.; Litos, M.; Fisher, A.D.; Hogan, M.J.; /SLAC

    2011-11-08

    FACET at SLAC provides high charge, high peak current, low emittance electron beam that is bunched at THz wavelength scale during its normal operation. A THz light source based coherent transition radiation (CTR) from this beam would potentially be the brightest short-pulse THz source ever constructed. Efforts have been put into building this photon source together with a user area, to provide a platform to utilize this unique THz radiation for novel nonlinear and ultrafast phenomena researches and experiments. Being a long-time underutilized portion of the electromagnetic spectrum, terahertz (100 GHz {approx} 10 THz) spectral range is experiencing a renaissance in recent years, with broad interests from chemical and biological imaging, material science, telecommunication, semiconductor and superconductor research, etc. Nevertheless, the paucity of THz sources especially strong THz radiation hinders both its commercial applications and nonlinear processes research. FACET - Facilities for Accelerator science and Experimental Test beams at SLAC - provides 23 GeV electron beam with peak currents of {approx} 20 kA that can be focused down to 100 {mu}m{sup 2} transversely. Such an intense electron beam, when compressed to sub-picosecond longitudinal bunch length, coherently radiates high intensity EM fields well within THz frequency range that are orders of magnitude stronger than those available from laboratory tabletop THz sources, which will enable a wide variety of THz related research opportunities. Together with a description of the FACET beamline and electron beam parameters, this paper will report FACET THz radiation generation via coherent transition radiation and calculated photon yield and power spectrum. A user table is being set up along the THz radiation extraction sites, and equipped with various signal diagnostics including THz power detector, Michelson interferometer, sample stages, and sets of motorized optical components. This setup will also be presented. Potential THz research areas including studies of magnetism, ferroelectric switching dynamics, semiconductor devices and chemical reaction controls have already been proposed for the FACET THz area.

  2. Morphological Traits Around Patellofemoral Joint in Indian Femora and their Implications

    PubMed Central

    Ghosh, Suchismita; Vasudeva, Neelam

    2014-01-01

    Introduction: Knowledge of structural variations around patellofemoral joint has helped to understand postural behavior patterns of various population groups. The biomechanical impact of postures may lead to certain skeletal modifications which may contribute to knee pathologies like patellofemoral arthritis, patellar subluxation and trochlear dysplasia. This study was conducted to report the incidence of skeletal non-metric markers on femur in Indian population and to understand their correlation with some pathologies of patellofemoral joint. The traits studied were Martin’s facet, Peritrochlear groove and Supratrochlear facet. Materials and Methods: The study material was a collection of 152 adult femora from osteology museum in Department of Anatomy, Maulana Azad Medical College, New Delhi, India, with equal percentage of bones from each side and gender. All bones were evaluated for the above mentioned traits and results were obtained as percentage of incidence and Chi-Square test using SPSS version 17. Results: The data showed that Martin’s facet and Peritrochlear groove showed a higher occurrence in male femora. However, Supratrochlear facet was more commonly found in female bones. Martin’s facet had an equal incidence on femora of each side while peritrochlear groove and supratrochlear facet had higher percentage of occurrence on right side. Supratrochlear facet revealed significant side variation. Conclusion: These data suggest that casual or occupational postures may impose structural adaptations around patell- ofemoral joint. The stress of these postures may have causal,consequential or co-incidental relationship with joint pathologies. The gender, special occupations like sports and genetic predisposition may possibly have a role to play. PMID:25302179

  3. Contribution of double interaction between edges and facets to monostatic RCS of complex targets

    Microsoft Academic Search

    M. Domingo; R. P. Torres; M. F. Catedra

    1992-01-01

    A method to calculate the effect of double interaction between edges and plane facets is presented. The calculation is made by combining the equivalent currents method and geometrical optics. The results are well suited to be added at the physical optics fields scattered by plane facets. The scheme is efficient for programming on computers together with a facets-edges model of

  4. Faceted Taxonomy-based Information Management Yannis Tzitzikas1,2

    E-print Network

    Analyti, Anastasia

    Faceted Taxonomy-based Information Management Yannis Tzitzikas1,2 and Anastasia Analyti2 1 of managing (faceted) taxonomy-based in- formation sources. Specifically, we discuss (i) the seman- tic description of faceted taxonomies, based on the Com- pound Term Composition Algebra (CTCA), (ii) the revision

  5. Compliant joint

    NASA Technical Reports Server (NTRS)

    Eklund, Wayne D. (inventor); Kerley, James J. (inventor)

    1990-01-01

    A compliant joint is provided for prosthetic and robotic devices which permits rotation in three different planes. The joint provides for the controlled use of cable under motion. Perpendicular outer mounting frames are joined by swaged cables that interlock at a center block. Ball bearings allow for the free rotation of the second mounting frame relative to the first mounting frame within a predetermined angular rotation that is controlled by two stop devices. The cables allow for compliance at the stops and the cables allow for compliance in six degrees of freedom enabling the duplication or simulation of the rotational movement and flexibility of a natural hip or knee joint, as well as the simulation of a joint designed for a specific robotic component for predetermined design parameters.

  6. Facet-controlled {100}Rh-Pt and {100}Pt-Pt dendritic nanostructures by transferring the {100} facet nature of the core nanocube to the branch nanocubes

    NASA Astrophysics Data System (ADS)

    Khi, Nguyen Tien; Park, Jongsik; Baik, Hionsuck; Lee, Hyunkyung; Sohn, Jeong-Hun; Lee, Kwangyeol

    2015-02-01

    Facet-controlled dendritic nanostructures are expected to exhibit excellent catalytic properties because both aggregation-free nature and controlled facet-originated activity and selectivity can be accomplished. However, such examples are extremely rare due to the incompatibility of the dendrite formation process with the usage of surface-stabilizing moieties, which are typically used to control facets. Herein, we demonstrate that regiospecific growth on a facet-controlled core nanoparticle can induce the facet-control of the branch nanoparticles. Specifically, facet-controlled dendritic nanostructures of {100}Rh-Pt and {100}Pt-Pt can be conveniently prepared by transferring the crystallographic behaviour of the {100}Pt dendritic core nanocube to the {100}Rh or {100}Pt branch nanocubes.Facet-controlled dendritic nanostructures are expected to exhibit excellent catalytic properties because both aggregation-free nature and controlled facet-originated activity and selectivity can be accomplished. However, such examples are extremely rare due to the incompatibility of the dendrite formation process with the usage of surface-stabilizing moieties, which are typically used to control facets. Herein, we demonstrate that regiospecific growth on a facet-controlled core nanoparticle can induce the facet-control of the branch nanoparticles. Specifically, facet-controlled dendritic nanostructures of {100}Rh-Pt and {100}Pt-Pt can be conveniently prepared by transferring the crystallographic behaviour of the {100}Pt dendritic core nanocube to the {100}Rh or {100}Pt branch nanocubes. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr07049f

  7. Development and Validation of a Synthetic Lumbar Facet Joint and its Load Bearing Characteristics

    E-print Network

    Mar, Damon

    2011-12-31

    There is a substantial need in the spine research community for an anatomical and mechanically correct synthetic model of the human lumbar spine. This model could be used in nearly every aspect of spinal research including the design of implants...

  8. Symmetry, topology and faceting in bicontinuous lyotropic crystals.

    PubMed

    Latypova, L; Gó?d?, W; Pieranski, P

    2013-08-01

    Phase diagrams of phytantriol/ethanol/water and phytantriol/DSPG/ethanol/water systems are explored and experiments on facetings of Pn3m-in-L1 and Im3m-in-L1 crystals are performed. Observed crystal habits do not agree with the Friedel-Donnay-Harker rules. We argue that this paradox can be explained in terms of constraints imposed on Pn3m/L1 and Im3m/L1 interfaces by the bicontinuous topology of the cubic phases. We point out that when free edges of the surfactant bilayer are prohibited at these interfaces, the two labyrinthes separated by the bilayer cannot anymore be equivalent. The corresponding [Formula: see text] and [Formula: see text] symmetry breakings are unveiled by the abnormal facetings. PMID:23933989

  9. Rapidly destructive osteoarthritis of the hip joint: a case series

    PubMed Central

    Batra, Sameer; Batra, Meenakshi; McMurtrie, A; Sinha, AK

    2008-01-01

    Background Rapidly destructive arthrosis of the hip is a rare and incompletely understood disorder with scarce literature about variations in natural history within a population. Methods A series of cases from North Wales with rapid progressive joint destruction and extensive subchondral bone loss in the femoral head and acetabulum are presented. Radiographic findings mimicked those of other disorders such as septic arthritis, rheumatoid and seronegative arthritis, primary osteonecrosis with secondary osteoarthritis, or neuropathic osteoarthropathy, but none of the patients had clinical, pathologic, or laboratory evidence of these entities. Results Rapid progression of hip pain and disability was a consistent clinical feature. The average duration of symptoms was 1.4 years. Radiographs obtained at various intervals before surgery (average 14 months) in 18 patients documented rapid hip destruction, involvement being unilateral in 13 cases. All patients underwent total hip arthroplasty, and osteoarthritis was confirmed at pathologic examination. Conclusion The authors postulate that these cases represent an uncommon subset of osteoarthritis and regular review, both clinically and radiologically, are required to assess speed of progression and prevent rapid loss of bone stock without the surgeon being aware. These cases are unsuitable for being placed on long waiting list due to technical difficulties in delayed surgery and compromised outcome following surgery. PMID:18190689

  10. Primary subtalar joint arthrodesis for comminuted fractures of the calcaneus.

    PubMed

    Holm, Janson L; Laxson, Steven E; Schuberth, John M

    2015-01-01

    Severely comminuted intra-articular calcaneal fractures often culminate in subtalar arthrosis and stiffness even after operative reduction. In some instances, subtalar arthrodesis is necessary to reduce the symptoms. Primary subtalar arthrodesis for these fractures has gained acceptance in recent years. However, few definite predictors of functional outcome after primary fusion have been found. A series of 17 patients with highly comminuted fractures were studied to determine which radiographic parameters were predictive of functional outcome. The American Orthopaedic Foot and Ankle Society Ankle-Hindfoot scale score was obtained at an average of 34 (range 12 to 157) months after arthrodesis. Radiographic measurements included the talocalcaneal, calcaneal inclination, talo-first metatarsal, and Böhler's angles, and the height of the tibial plafond, width of the calcaneus, and the presence of a medial step-off on the injured and uninjured foot. The mean Ankle-Hindfoot scale score was 78 (range 56 to 92), and the mean visual analog score was 1.9 (0 to 4). Statistically significant associations were noted between greater postoperative function and increasing age (p = .028), the quality of restoration of Böhler's angle (p = .038), and the talocalcaneal angle (p = .049). No patient had nonunion. The results of the present study suggest that the outcomes after primary arthrodesis of the subtalar joint are favorable, in particular, when the radiographic relationships of the hindfoot have been restored. PMID:25176004

  11. Selective facet reactivity during cation exchange in cadmium sulfide nanorods.

    PubMed

    Sadtler, Bryce; Demchenko, Denis O; Zheng, Haimei; Hughes, Steven M; Merkle, Maxwell G; Dahmen, Ulrich; Wang, Lin-Wang; Alivisatos, A Paul

    2009-04-15

    The partial transformation of ionic nanocrystals through cation exchange has been used to synthesize nanocrystal heterostructures. We demonstrate that the selectivity for cation exchange to take place at different facets of the nanocrystal plays an important role in determining the resulting morphology of the binary heterostructure. In the case of copper(I) (Cu(+)) cation exchange in cadmium sulfide (CdS) nanorods, the reaction starts preferentially at the ends of the nanorods such that copper sulfide (Cu(2)S) grows inward from either end. The resulting morphology is very different from the striped pattern obtained in our previous studies of silver(I) (Ag(+)) exchange in CdS nanorods where nonselective nucleation of silver sulfide (Ag(2)S) occurs (Robinson, R. D.; Sadtler, B.; Demchenko, D. O.; Erdonmez, C. K.; Wang, L.-W.; Alivisatos, A. P. Science 2007, 317, 355-358). From interface formation energies calculated for several models of epitaxial connections between CdS and Cu(2)S or Ag(2)S, we infer the relative stability of each interface during the nucleation and growth of Cu(2)S or Ag(2)S within the CdS nanorods. The epitaxial attachments of Cu(2)S to the end facets of CdS nanorods minimize the formation energy, making these interfaces stable throughout the exchange reaction. Additionally, as the two end facets of wurtzite CdS nanorods are crystallographically nonequivalent, asymmetric heterostructures can be produced. PMID:19351206

  12. Selective Facet Reactivity During Cation Exchange in Cadmium Sulfide Nanorods

    SciTech Connect

    Sadtler, Bryce; Demchenko, Denis; Zheng, Haimei; Hughes, Steven; Merkle, Maxwell; Dahmen, Ulrich; Wang, Lin-Wang; Alivisatos, A. Paul

    2008-12-18

    The partial transformation of ionic nanocrystals through cation exchange has been used to synthesize nanocrystal heterostructures. We demonstrate that the selectivity for cation exchange to take place at different facets of the nanocrystal plays an important role in determining the resulting morphology of the binary heterostructure. In the case of copper I (Cu+) cation exchange in cadmium sulfide (CdS) nanorods, the reaction starts preferentially at the ends of the nanorods such that copper sulfide (Cu2S) grows inwards from either end. The resulting morphology is very different from the striped pattern obtained in our previous studies of silver I (Ag+) exchange in CdS nanorods where non-selective nucleation of silver sulfide (Ag2S) occurs. From interface formation energies calculated for several models of epitaxialconnections between CdS and Cu2S or Ag2S, we infer the relative stability of each interface during the nucleation and growth of Cu2S or Ag2S within the CdS nanorods. The epitaxial connections of Cu2S to the end facets of CdS nanorods minimize the formation energy, making these interfaces stable throughout the exchange reaction. However, as the two end facets of wurtzite CdS nanorods are crystallographically nonequivalent, asymmetric heterostructures can be produced.

  13. Framework Application for Core Edge Transport Simulation (FACETS)

    SciTech Connect

    Krasheninnikov, Sergei; Pigarov, Alexander

    2011-10-15

    The FACETS (Framework Application for Core-Edge Transport Simulations) project of Scientific Discovery through Advanced Computing (SciDAC) Program was aimed at providing a high-fidelity whole-tokamak modeling for the U.S. magnetic fusion energy program and ITER through coupling separate components for each of the core region, edge region, and wall, with realistic plasma particles and power sources and turbulent transport simulation. The project also aimed at developing advanced numerical algorithms, efficient implicit coupling methods, and software tools utilizing the leadership class computing facilities under Advanced Scientific Computing Research (ASCR). The FACETS project was conducted by a multi-discipline, multi-institutional teams, the Lead PI was J.R. Cary (Tech-X Corp.). In the FACETS project, the Applied Plasma Theory Group at the MAE Department of UCSD developed the Wall and Plasma-Surface Interaction (WALLPSI) module, performed its validation against experimental data, and integrated it into the developed framework. WALLPSI is a one-dimensional, coarse grained, reaction/advection/diffusion code applied to each material boundary cell in the common modeling domain for a tokamak. It incorporates an advanced model for plasma particle transport and retention in the solid matter of plasma facing components, simulation of plasma heat power load handling, calculation of erosion/deposition, and simulation of synergistic effects in strong plasma-wall coupling.

  14. LEEM Investigation of the Faceting of the Pt Covered W (111) Surface

    SciTech Connect

    Hannon, J.B.; Kellogg, G.L.; Madey, T.E.; Pelhos, K.

    1999-01-20

    A low energy electron microscope (LEEM) has been used to investigate the faceting of W(111) as induced by Pt. The atomically rough W(111) surface, when fully covered with a monolayer film of Pt and annealed to temperatures higher than {approximately} 750 K, experiences a significant morphological restructuring: the initially planar surface undergoes a faceting transition and forms three-sided pyramids with {211} faces. The experiments demonstrate the capability of LEEM for imaging both the fully and partially faceted surface. In addition, we have observed the formation of the facets in real time, when Pt is dosed onto the heated surface. We find that the transition from planar surface, to partially faceted surface, and to fully faceted surface proceeds through the nucleation and growth of spatially separated faceted regions.

  15. Simulated Whiplash Modulates Expression of the Glutamatergic System in the Spinal Cord Suggesting Spinal Plasticity Is Associated with Painful Dynamic Cervical Facet Loading

    PubMed Central

    Dong, Ling

    2010-01-01

    Abstract The cervical facet joint and its capsule have been reported to be injured during whiplash scenarios and are a common source of chronic neck pain from whiplash. Both the metabotropic glutamate receptor 5 (mGluR5) and the excitatory amino acid carrier 1 (EAAC1) have pivotal roles in chronic pain. In this study, spinal mGluR5 and EAAC1 were quantified following painful facet joint distraction in a rat model of facet-mediated painful loading and were evaluated for their correlation with the severity of capsule loading. Rats underwent either a dynamic C6/C7 joint distraction simulating loading experienced during whiplash (distraction; n?=?12) or no distraction (sham; n?=?6) to serve as control. The severity of capsular loading was quantified using strain metrics, and mechanical allodynia was assessed after surgery. Spinal cord tissue was harvested at day 7 and the expression of mGluR5 and EAAC1 were quantified using Western blot analysis. Mechanical allodynia following distraction was significantly (p?joint loading; chronic whiplash pain may be alleviated by blocking mGluR5 expression and/or enhancing glutamate transport through the neuronal transporter EAAC1. PMID:19772459

  16. Joint chondrolysis.

    PubMed

    Provencher, Matthew T; Navaie, Maryam; Solomon, Daniel J; Smith, Jessica C; Romeo, Anthony A; Cole, Brian J

    2011-11-01

    Although the disease was first described in the hip, reports of chondrolysis in nearly all diarthrodial joints have since emerged with considerable variations in the literature.Despite speculation among clinicians and researchers about the implicit causal pathways and etiologic contributors associated with chondrolysis, definitive answers remain elusive.The term chondrolysis has been applied to varied levels of joint cartilage destruction from focal chondral defects to diffuse cartilage loss, revealing a lack of consistency in the application of diagnostic criteria to guide differential disease classification.Differentiating between the various potential etiologies associated with chondrolysis provides opportunities for the prevention of the disease. PMID:22048100

  17. Hip joint replacement

    MedlinePLUS

    ... made joint. The artificial joint is called a prosthesis . ... thromboembolic disease in patients undergoing elective hip and ... joint arthroplasties: current concepts of patient outcomes after ...

  18. Use of computed tomography-single-photon emission computed tomography fusion for diagnosing painful facet arthropathy. Technical note.

    PubMed

    McDonald, Matthew; Cooper, Robert; Wang, Michael Y

    2007-01-01

    Facet disease is believed to play a major role in axial low-back pain and may prove in the future to be an important indication for posterior dynamic stabilization. However, the lack of good diagnostic tests and imaging methods for identifying this condition have made this entity obscure. Although single-photon emission computed tomography (SPECT) imaging is a highly sensitive and specific test, the images frequently lack adequate resolution, whereas computed tomography (CT) provides excellent resolution but lacks specificity. Thirty-seven patients with back pain clinically attributable to facet disease underwent CT-SPECT fusion imaging of the lumbar spine. The SPECT images were obtained using a dual-head gamma camera equipped with VXGP high-resolution collimators using a 20% energy window centered at 140 keV and a 360 degrees rotation totaling 128 projections at 16 seconds each. Transaxial CT images were transferred in the Digital Imaging and Communications in Medicine format to provide proper image overlay in the axial, sagittal, and coronal planes. Scanning for both modalities was performed using standard patient positioning. Patients with concordant images and symptoms then underwent joint injection and/or rhizotomy, which was performed by an independent physician. Image fusion was successfully performed in all patients, and the image quality allowed definitive localization of the "hot" lesion in all cases, in contrast to conventional high-resolution SPECT scanning, which often led to problems differentiating L4/5 and L5/S1. In patients with solitary lesions, injection led to definitive pain resolution, even if temporary, in all cases with anesthetic blockade. The CT-SPECT scanning modality combines the virtues of functional and anatomical imaging, aiding the clinician in making the diagnosis of painful facet arthropathy. This modality may prove useful for the selection of patients who are candidates for posterior dynamic stabilization. PMID:17608336

  19. Status of Plasma Electron Hose Instability Studies in FACET

    SciTech Connect

    Adli, Erik; /U. Oslo; England, Robert Joel; Frederico, Joel; Hogan, Mark; Li, Selina Zhao; Litos, Michael Dennis; Nosochkov, Yuri; /SLAC; An, Weiming; Mori, Warren; /UCLA

    2011-12-13

    In the FACET plasma-wakefield acceleration experiment a dense 23 GeV electron beam will interact with lithium and cesium plasmas, leading to plasma ion-channel formation. The interaction between the electron beam and the plasma sheath-electrons may lead to a fast growing electron hose instability. By using optics dispersion knobs to induce a controlled z-x tilt along the beam entering the plasma, we investigate the transverse behavior of the beam in the plasma as function of the tilt. We seek to quantify limits on the instability in order to further explore potential limitations on future plasma wakefield accelerators due to the electron hose instability. The FACET plasma-wakefield experiment at SLAC will study beam driven plasma wakefield acceleration. A dense 23 GeV electron beam will interact with lithium or cesium plasma, leading to plasma ion-channel formation. The interaction between the electron beam and the plasma sheath-electrons drives the electron hose instability, as first studied by Whittum. While Ref. [2] indicates the possibility of a large instability growth rate for typical beam and plasma parameters, other studies including have shown that several physical effects may mitigate the hosing growth rate substantially. So far there has been no quantitative benchmarking of experimentally observed hosing in previous experiments. At FACET we aim to perform such benchmarking by for example inducing a controlled z-x tilt along the beamentering the plasma, and observing the transverse behavior of the beam in the plasma as function. The long-term objective of these studies is to quantify potential limitations on future plasma wakefield accelerators due to the electron hose instability.

  20. Sub-Facet Heterogeneity of the Urban Surface Energy Budget

    NASA Astrophysics Data System (ADS)

    Ramamurthy, P.; Bou-Zeid, E.; Smith, J. A.; Baeck, M. L.; Welty, C.

    2013-12-01

    The Princeton Urban Canopy Model (PUCM) and observational data are combined to understand the influence of urban sub-facet heterogeneity, and the associated influence of material properties, on the urban surface energy budget. This heterogeneity is related to the different surfaces and materials (asphalt, concrete, grass, black roofs, green roofs, etc.) that are typically found within one urban facet (roof, wall, and ground). Of particular interest is the role of water storage and evaporation from urban surfaces in modulating the energy budget. The PUCM is evaluated at sites of various urban densities. Subsequently, one densely-built site is selected for in-depth analysis and the model is applied, with sub-facet resolution, to simulate the water and energy budgets. Our analyses show that while all built surfaces convert most of the incoming energy into sensible rather than latent heat, sensible heat fluxes from asphalt and non-reflective rooftops are twice as high as those from concrete surfaces and light colored roofs. Another important and commonly observed characteristic of urban areas- the shift in peak time of sensible heat compared to rural areas, is shown to be mainly linked to concrete's high heat storage capacity. Our results also indicate that while evaporation from built surfaces is discontinuous and intermittent, overall, these surfaces accounted for nearly 16% of latent heat fluxes (LE) at the study site during the study period. More importantly, this contribution is mainly concentrated during the 48 hours following a rain event and thus its accurate representation is critical to our understanding of the urban surface energy budget during wet periods.

  1. Model for reflection and transmission matrices of nanowire end facets

    NASA Astrophysics Data System (ADS)

    Svendsen, Guro K.; Weman, Helge; Skaar, Johannes

    2011-05-01

    Nanowires show a large potential for various electro-optical devices, such as light emitting diodes, solar cells, and nanowire lasers. We present a method developed to calculate the modal reflection and transmission matrix at the end facets of a waveguide of arbitrary cross-section, resulting in a generalized version of the Fresnel equations. The reflection can be conveniently computed using fast Fourier transforms once the waveguide modes are known. We demonstrate that the reflection coefficient is qualitatively described by two main parameters: the modal field confinement and the average Fresnel reflection of the plane waves constituting the waveguide mode.

  2. Optimization of spherical facets for parabolic solar concentrators

    NASA Technical Reports Server (NTRS)

    White, J. E.; Erikson, R. J.; Sturgis, J. D.; Elfe, T. B.

    1986-01-01

    Solar concentrator designs which employ deployable hexagonal panels are being developed for space power systems. An offset optical configuration has been developed which offers significant system level advantages over previously proposed collector designs for space applications. Optical analyses have been performed which show offset reflector intercept factors to be only slightly lower than those for symmetric reflectors with the same slope error. Fluxes on the receiver walls are asymmetric but manageable by varying the tilt angle of the receiver. Greater producibility is achieved by subdividing the hexagonal panels into triangular mirror facets of spherical contour. Optical analysis has been performed upon these to yield near-optimum sizes and radii.

  3. Reverse Epitaxy of Ge: Ordered and Faceted Surface Patterns

    NASA Astrophysics Data System (ADS)

    Ou, Xin; Keller, Adrian; Helm, Manfred; Fassbender, Jürgen; Facsko, Stefan

    2013-07-01

    Normal incidence ion irradiation at elevated temperatures, when amorphization is prevented, induces novel nanoscale patterns of crystalline structures on elemental semiconductors by a reverse epitaxial growth mechanism: on Ge surfaces irradiation at temperatures above the recrystallization temperature of 250°C leads to self-organized patterns of inverse pyramids. Checkerboard patterns with fourfold symmetry evolve on the Ge (100) surface, whereas on the Ge (111) surface, isotropic patterns with a sixfold symmetry emerge. After high-fluence irradiations, these patterns exhibit well-developed facets. A deterministic nonlinear continuum equation accounting for the effective surface currents due to an Ehrlich-Schwoebel barrier for diffusing vacancies reproduces remarkably well our experimental observations.

  4. Facility for Advanced Accelerator Experimental Tests (FACET) at SLAC and its Radiological Considerations

    SciTech Connect

    Mao, X.S.; Leitner, M.Santana; Vollaire, J.

    2011-08-22

    Facility for Advanced Accelerator Experimental Tests (FACET) in SLAC will be used to study plasma wakefield acceleration. FLUKA Monte Carlo code was used to design a maze wall to separate FACET project and LCLS project to allow persons working in FACET side during LCLS operation. Also FLUKA Monte Carlo code was used to design the shielding for FACET dump to get optimum design for shielding both prompt and residual doses, as well as reducing environmental impact. FACET will be an experimental facility that provides short, intense pulses of electrons and positrons to excite plasma wakefields and study a variety of critical issues associated with plasma wakefield acceleration [1]. This paper describes the FACET beam parameters, the lay-out and its radiological issues.

  5. Joint assembly

    NASA Technical Reports Server (NTRS)

    Wilson, Andrew (Inventor); Punnoose, Andrew (Inventor); Strausser, Katherine (Inventor); Parikh, Neil (Inventor)

    2010-01-01

    A joint assembly is provided which includes a drive assembly and a swivel mechanism. The drive assembly features a motor operatively associated with a plurality of drive shafts for driving auxiliary elements, and a plurality of swivel shafts for pivoting the drive assembly. The swivel mechanism engages the swivel shafts and has a fixable element that may be attached to a foundation. The swivel mechanism is adapted to cooperate with the swivel shafts to pivot the drive assembly with at least two degrees of freedom relative to the foundation. The joint assembly allows for all components to remain encased in a tight, compact, and sealed package, making it ideal for space, exploratory, and commercial applications.

  6. Testing of the SAIC facets on the stretched-membrane dish

    Microsoft Academic Search

    J. W. Grossman; W. W. Erdman; R. M. Houser; R. Davenport

    1994-01-01

    A dish structure sized for a 25 kW electric dish\\/generator system has been installed at the National Solar Thermal Test Facility (NSTTF). The dish is used as an optical test bed for prototype stretched-membrane facets. Sandia procured twelve (12) stretched-membrane facets from Science Applications International Corporation (SAIC) for installation on the dish structure. Individual facet optical performance was measured using

  7. GaN-based LEDs with Al-deposited V-shaped sapphire facet mirror

    Microsoft Academic Search

    Y. J. Lee; J. M. Hwang; T. C. Hsu; M. H. Hsieh; M. J. Jou; B. J. Lee; T. C. Lu; H. C. Kuo; S. C. Wang

    2006-01-01

    A GaN-based light-emitting diodes (LEDs) with V-shaped sapphire facet reflector was fabricated using the double transferred scheme and sapphire chemical wet etching. The {1-102} R-plane V-shaped facet reflector with a 57° against {0001} C-axis has the superior capability for enhancing the light extraction efficiency. The light output power of the V-shaped sapphire facet reflector LED was 1.4 times higher than

  8. Comparing Linkage Designs Based on Land Facets to Linkage Designs Based on Focal Species

    PubMed Central

    Brost, Brian M.; Beier, Paul

    2012-01-01

    Least-cost modeling for focal species is the most widely used method for designing conservation corridors and linkages. However, these designs depend on today's land covers, which will be altered by climate change. We recently proposed an alternative approach based on land facets (recurring landscape units of relatively uniform topography and soils). The rationale is that corridors with high continuity of individual land facets will facilitate movement of species associated with each facet today and in the future. Conservation practitioners might like to know whether a linkage design based on land facets is likely to provide continuity of modeled breeding habitat for species needing connectivity today, and whether a linkage for focal species provides continuity and interspersion of land facets. To address these questions, we compared linkages designed for focal species and land facets in three landscapes in Arizona, USA. We used two variables to measure linkage utility, namely distances between patches of modeled breeding habitat for 5–16 focal species in each linkage, and resistance profiles for focal species and land facets between patches connected by the linkage. Compared to focal species designs, linkage designs based on land facets provided as much or more modeled habitat connectivity for 25 of 28 species-landscape combinations, failing only for the three species with the most narrowly distributed habitat. Compared to land facets designs, focal species linkages provided lower connectivity for about half the land facets in two landscapes. In areas where a focal species approach to linkage design is not possible, our results suggest that conservation practitioners may be able to implement a land facets approach with some confidence that the linkage design would serve most potential focal species. In areas where focal species designs are possible, we recommend using the land facet approach to complement, rather than replace, focal species approaches. PMID:23152831

  9. Interactive exploration of implicit and explicit relations in faceted datasets.

    PubMed

    Zhao, Jian; Collins, Christopher; Chevalier, Fanny; Balakrishnan, Ravin

    2013-12-01

    Many datasets, such as scientific literature collections, contain multiple heterogeneous facets which derive implicit relations, as well as explicit relational references between data items. The exploration of this data is challenging not only because of large data scales but also the complexity of resource structures and semantics. In this paper, we present PivotSlice, an interactive visualization technique which provides efficient faceted browsing as well as flexible capabilities to discover data relationships. With the metaphor of direct manipulation, PivotSlice allows the user to visually and logically construct a series of dynamic queries over the data, based on a multi-focus and multi-scale tabular view that subdivides the entire dataset into several meaningful parts with customized semantics. PivotSlice further facilitates the visual exploration and sensemaking process through features including live search and integration of online data, graphical interaction histories and smoothly animated visual state transitions. We evaluated PivotSlice through a qualitative lab study with university researchers and report the findings from our observations and interviews. We also demonstrate the effectiveness of PivotSlice using a scenario of exploring a repository of information visualization literature. PMID:24051774

  10. Intensity Effects of the FACET Beam in the SLAC Linac

    SciTech Connect

    Decker, F.-J.; Lipkowitz, N.; Sheppard, J.; White, G.R.; Wienands, U.; Woodley, M.; Yocky, G.; /SLAC

    2012-07-03

    The beam for FACET (Facility for Advanced aCcelerator Experimental Tests) at SLAC requires an energy-time correlation ('chirp') along the linac, so it can be compressed in two chicanes, one at the midpoint in sector 10 and one W-shaped chicane just before the FACET experimental area. The induced correlation has the opposite sign to the typical used for BNS damping, and therefore any orbit variations away from the center kick the tail of the beam more than the head, causing a shear in the beam and emittance growth. Any dispersion created along the linac has similar effects due to the high (>1.2% rms) energy spread necessary for compression. The initial huge emittances could be reduced by a factor of 10, but were still bigger than expected by a factor of 2-3. Normalized emittance of 3 {micro}m-rad in Sector 2 blew up to 150 {micro}m-rad in Sector 11 but could be reduced to about 6-12 {micro}m-rad, for the vertical plane although the results were not very stable. Investigating possible root causes for this, we found locations where up to 10 mm dispersion was created along the linac, which were finally verified with strong steering and up to 7 mm settling of the linac accelerator at these locations.

  11. FACET: an object-oriented software framework for modeling complex social behavior patterns

    SciTech Connect

    Dolph, J. E.; Christiansen, J. H.; Sydelko, P. J.

    2000-06-30

    The Framework for Addressing Cooperative Extended Transactions (FACET) is a flexible, object-oriented architecture for implementing models of dynamic behavior of multiple individuals, or agents, in a simulation. These agents can be human (individuals or organizations) or animal and may exhibit any type of organized social behavior that can be logically articulated. FACET was developed by Argonne National Laboratory's (ANL) Decision and Information Sciences Division (DIS) out of the need to integrate societal processes into natural system simulations. The FACET architecture includes generic software components that provide the agents with various mechanisms for interaction, such as step sequencing and logic, resource management, conflict resolution, and preemptive event handling. FACET components provide a rich environment within which patterns of behavior can be captured in a highly expressive manner. Interactions among agents in FACET are represented by Course of Action (COA) object-based models. Each COA contains a directed graph of individual actions, which represents any known pattern of social behavior. The agents' behavior in a FACET COA, in turn, influences the natural landscape objects in a simulation (i.e., vegetation, soil, and habitat) by updating their states. The modular design of the FACET architecture provides the flexibility to create multiple and varied simulation scenarios by changing social behavior patterns, without disrupting the natural process models. This paper describes the FACET architecture and presents several examples of FACET models that have been developed to assess the effects of anthropogenic influences on the dynamics of the natural environment.

  12. Arthroscopy of the subtalar joint: an experimental approach.

    PubMed

    Parisien, J S; Vangsness, T

    1985-01-01

    Talocalcaneal articulations are relatively complex and functionally very important because they play a major role in the movements of inversion and eversion of the foot. Few reports on arthrography of the subtalar joints are available in the literature, and, similarly, little attention has been paid by arthroscopists to these joints. This preliminary study briefly defines the normal anatomy of the subtalar joints and describes a new technique of arthroscopic examination of the posterior subtalar joint. The distal lower extremities of six fresh cadavers were used in these experiments. All the subtalar joints were supple. A 2.7-mm arthroscope was used to carry out arthroscopic and anatomic examinations. A technique of examination with one anterior portal and one posterior portal is described in detail. When the anterior portal was used, the egress needle was placed posteriorly; when the posterior portal was used, the converse was true. By using the two portals, the following intraarticular structures could be visualized: a major part of the convex posterior calcaneal facet of the talus and the posterior talar facet of the calcaneus; the synovial lining laterally and posteriorly; the posterior aspect of the interosseous talocalcaneal ligament; and the posterior recess of the joint. The results of this experimental study indicate that arthroscopy of the posterior subtalar joint is technically feasible. Clinically, the possible indications for arthroscopy would include state of the articular cartilage in suspected cases of degenerative arthritis, rheumatoid arthritis, and infection; visualization of the joint after intraarticular fracture to evaluate chronic pain syndrome in the hindfoot; biopsy; management of sinus tarsi syndrome; loose body removal. PMID:4091910

  13. Autologous adipose stem cells and polylactide discs in the replacement of the rabbit temporomandibular joint disc

    PubMed Central

    Ahtiainen, Katja; Mauno, Jari; Ellä, Ville; Hagström, Jaana; Lindqvist, Christian; Miettinen, Susanna; Ylikomi, Timo; Kellomäki, Minna; Seppänen, Riitta

    2013-01-01

    The temporomandibular joint (TMJ) disc lacks functional replacement after discectomy. We investigated tissue-engineered bilayer polylactide (PLA) discs and autologous adipose stem cells (ASCs) as a potential replacement for the TMJ disc. These ASC discs were pre-cultured either in control or in differentiation medium, including transforming growth factor (TGF)-?1 for one week. Prior to implantation, expression of fibrocartilaginous genes was measured by qRT-PCR. The control and differentiated ASC discs were implanted, respectively, in the right and left TMJs of rabbits for six (n = 5) and 12 months (n = 5). Thereafter, the excised TMJ areas were examined with cone beam computed tomography (CBCT) and histology. No signs of infection, inflammation or foreign body reactions were detected at histology, whereas chronic arthrosis and considerable condylar hypertrophy were observed in all operated joints at CBCT. The left condyle treated with the differentiated ASC discs appeared consistently smoother and more sclerotic than the right condyle. The ASC disc replacement resulted in dislocation and morphological changes in the rabbit TMJ. The ASC discs pre-treated with TGF-?1 enhanced the condylar integrity. While adverse tissue reactions were not shown, the authors suggest that with improved attachment and design, the PLA disc and biomaterial itself would hold potential for TMJ disc replacement. PMID:23720535

  14. Facet-Dependent Photoelectrochemical Performance of TiO2 Nanostructures: An Experimental and Computational Study.

    PubMed

    Li, Chuanhao; Koenigsmann, Christopher; Ding, Wendu; Rudshteyn, Benjamin; Yang, Ke R; Regan, Kevin P; Konezny, Steven J; Batista, Victor S; Brudvig, Gary W; Schmuttenmaer, Charles A; Kim, Jae-Hong

    2015-02-01

    The behavior of crystalline nanoparticles depends strongly on which facets are exposed. Some facets are more active than others, but it is difficult to selectively isolate particular facets. This study provides fundamental insights into photocatalytic and photoelectrochemical performance of three types of TiO2 nanoparticles with predominantly exposed {101}, {010}, or {001} facets, where 86-99% of the surface area is the desired facet. Photodegradation of methyl orange reveals that {001}-TiO2 has 1.79 and 3.22 times higher photocatalytic activity than {010} and {101}-TiO2, respectively. This suggests that the photochemical performance is highly correlated with the surface energy and the number of under-coordinated surface atoms. In contrast, the photoelectrochemical performance of the faceted TiO2 nanoparticles sensitized with the commercially available MK-2 dye was highest with {010}-TiO2 which yielded an overall cell efficiency of 6.1%, compared to 3.2% for {101}-TiO2 and 2.6% for {001}-TiO2 prepared under analogous conditions. Measurement of desorption kinetics and accompanying computational modeling suggests a stronger covalent interaction of the dye with the {010} and {101} facets compared with the {001} facet. Time-resolved THz spectroscopy and transient absorption spectroscopy measure faster electron injection dynamics when MK-2 is bound to {010} compared to other facets, consistent with extensive computational simulations which indicate that the {010} facet provides the most efficient and direct pathway for interfacial electron transfer. Our experimental and computational results establish for the first time that photoelectrochemical performance is dependent upon the binding energy of the dye as well as the crystalline structure of the facet, as opposed to surface energy alone. PMID:25563343

  15. Aerodynamics Investigation of Faceted Airfoils at Low Reynolds Number

    NASA Astrophysics Data System (ADS)

    Napolillo, Zachary G.

    The desire and demand to fly farther and faster has progressively integrated the concept of optimization with airfoil design, resulting in increasingly complex numerical tools pursuing efficiency often at diminishing returns; while the costs and difficulty associated with fabrication increases with design complexity. Such efficiencies may often be necessary due to the power density limitations of certain aircraft such as small unmanned aerial vehicles (UAVs) and micro air vehicles (MAVs). This research, however, focuses on reducing the complexity of airfoils for applications where aerodynamic performance is less important than the efficiency of manufacturing; in this case a Hybrid Projectile. By employing faceted sections to approximate traditional contoured wing sections it may be possible to expedite manufacturing and reduce costs. We applied this method to the development of a low Reynolds number, disposable Hybrid Projectile requiring a 4.5:1 glide ratio, resulting in a series of airfoils which are geometric approximations to highly contoured cross-sections called ShopFoils. This series of airfoils both numerically and experimentally perform within a 10% margin of the SD6060 airfoil at low Re. Additionally, flow visualization has been conducted to qualitatively determine what mechanisms, if any, are responsible for the similarity in performance between the faceted ShopFoil sections and the SD6060. The data obtained by these experiments did not conclusively reveal how the faceted surfaces may influence low Re flow but did indicate that the ShopFoil s did not maintain flow attachment at higher angles of attack than the SD6060. Two reasons are provided for the unexpected performance of the ShopFoil: one is related to downwash effects, which are suspected of placing the outer portion of the span at an effective angle of attack where the ShopFoils outperform the SD6060; the other is the influence of the tip vortex on separation near the wing tips, which possibly provides a 'comparative advantage' to the ShopFoil because it has more to gain from a reduction in its pressure drag component.

  16. Intra-articular calcaneal fractures: effect of open reduction and internal fixation on the contact characteristics of the subtalar joint.

    PubMed

    Mulcahy, D M; McCormack, D M; Stephens, M M

    1998-12-01

    Intra-articular calcaneal fractures are associated with significant long-term morbidity, and considerable controversy exists regarding the optimum method of treating them. The contact characteristics in the intact subtalar joint were determined at known loads and for different positions of the ankle and subtalar joint, using pressure-sensitive film (Super Low; Fuji, Itochu Canada Ltd, Montreal, Quebec). We measured the contact area to joint area ratio (pressure > 5 kg force/cm2 [kgf/cm2]) which normalizes for differences in joint size and the ratio of high pressure zone (>20 kgf/cm2) as a reflection of overall increase in joint pressure. Three simulated fracture patterns were then created and stabilized with either 1 or 2 mm of articular incongruity. Eight specimens were prepared with a primary fracture line through the posterior facet, eight with a joint depression-type fracture, and six with a central joint depression fracture. A measure of 1 to 2 mm of incongruity in the posterior facet for all three fracture patterns produced significant unloading of the depressed fragment, with a redistribution of the overall pattern of pressure distribution to parts of the facet that were previously unloaded. PMID:9872472

  17. Do Different Facets of Impulsivity Predict Different Types of Aggression?

    PubMed Central

    Derefinko, Karen; DeWall, C. Nathan; Metze, Amanda V.; Walsh, Erin C.; Lynam, Donald R.

    2011-01-01

    The current study examined the relations between impulsivity-related traits (as assessed by the UPPS-P Impulsive Behavior Scale) and aggressive behaviors. Results indicated that UPPS-P Lack of Premeditation and Sensation Seeking were important in predicting general violence. In contrast, UPPS-P Urgency was most useful in predicting intimate partner violence. To further explore relations between intimate partner violence and Urgency, a measure of autonomic response to pleasant and aversive stimuli and facets of Neuroticism from the NEO PI-R were used as control variables. Autonomic responsivity was correlated with intimate partner violence at the zero-order level, and predicted significant variance in intimate partner violence in regression equations. However, UPPS-P Urgency was able to account for unique variance in intimate partner violence above and beyond measures of Neuroticism and arousal. Implications regarding the use of a multifaceted conceptualization of impulsivity in the prediction of different types of violent behavior are discussed. PMID:21259270

  18. Micro-Facet Scattering Model for Pulse Polarization Ranging

    NASA Astrophysics Data System (ADS)

    Stryjewski, J.; Roggemann, M.; Tyler, D.; Hand, D.

    Determining the shape, material and orientation of nano-sats (satellites too small to image from the ground) requires new sensing approaches. Pulse Polarization Ranging (PPR) is one such approach that uses the polarization and shape characteristics of laser pulses reflected from satellites to determine satellite shape, orientation and material. We use an innovative approach to relate PPR measurements to actual satellite characteristics (shape, material and orientation), requiring that we have an accurate physical and dynamical model of the satellite. In particular, to determine the polarization characteristics (depolarization, birefringence, diattenuation) of the reflected pulses we need an accurate model of light scattering from real (complex) surfaces. To do this, we have extended the micro-facet model of Ashikhmin et al. to include retro-reflection and multiple scattering effects. In this presentation, we describe the scattering model and its efficient implementation using graphical processing units (GPUs).

  19. Examining student rating of teaching effectiveness using FACETS.

    PubMed

    Mat Daud, Nuraihan; Abu Kassim, Noor Lide

    2011-01-01

    Students' evaluations of teaching staff can be considered high-stakes, as they are often used to determine promotion, reappointment, and merit pay to academics. Using Facets, the reliability and validity of one student rating questionnaire is analyzed. A total of 13,940 respondents of the Human Science Division of International Islamic University Malaysia were involved in the study. The analysis shows that the student rating questionnaire used was valid and reliable, and it allows identification of staff for the institution's prestigious teaching excellence awards, and those needing in-service training. It was found that there was no significant difference in terms of rank, age and gender of the staff. The study also shows that the majority of staff have problems keeping the class interested and getting students to participate in class activities. Faculty also hardly discussed common errors in assignments and tests. PMID:22089510

  20. Replicable Facets of Positive Emotionality and Their Relations to Psychopathology.

    PubMed

    Stanton, Kasey; Watson, David

    2014-09-26

    General individual differences in positive emotionality are negatively related to depression, social anxiety, and schizotypy/schizophrenia, and positively related to mania. However, the structure of positive emotionality remains unclear at the facet level, as there are significant disparities in the types of content assessed across emotionality measures. This study analyzed the lower order structure of positive emotionality in two samples, finding evidence for a replicable two-factor structure of Joviality and Experience Seeking. These factors demonstrated a markedly different pattern of relations in both direction and magnitude with internalizing, externalizing, and schizotypal symptoms. Joviality seems to represent an adaptive variant of positive emotionality, as it showed strong positive relations with well-being and moderate negative relations with measures of depression, social anxiety, and social anhedonia. In contrast, Experience Seeking appears to be somewhat maladaptive. It generally related positively to psychopathology, correlating most strongly with indicators of manic and externalizing symptoms. PMID:25260942

  1. Giant photoluminescence emission in crystalline faceted Si grains

    PubMed Central

    Faraci, Giuseppe; Pennisi, Agata R.; Alberti, Alessandra; Ruggeri, Rosa; Mannino, Giovanni

    2013-01-01

    Empowering an indirect band-gap material like Si with optical functionalities, firstly light emission, represents a huge advancement constantly pursued in the realization of any integrated photonic device. We report the demonstration of giant photoluminescence (PL) emission by a newly synthesized material consisting of crystalline faceted Si grains (fg-Si), a hundred nanometer in size, assembled in a porous and columnar configuration, without any post processing. A laser beam with wavelength 632.8?nm locally produce such a high temperature, determined on layers of a given thickness by Raman spectra, to induce giant PL radiation emission. The optical gain reaches the highest value ever, 0.14?cm/W, representing an increase of 3 orders of magnitude with respect to comparable data recently obtained in nanocrystals. Giant emission has been obtained from fg-Si deposited either on glass or on flexible, low cost, polymeric substrate opening the possibility to fabricate new devices. PMID:24056300

  2. Soft tissue injuries associated with traumatic locked facets in the cervical spine

    Microsoft Academic Search

    A C Moraes; A Serdeira; A Pereira Filho; E Zardo; J Deitos

    1995-01-01

    The clinical, radiological and operative findings in 10 consecutive patients with cervical spine trauma presenting with locked facets (bilaterally in nine patients) are reported. The treatment was cervical traction until reduction of the locked facets was achieved, followed by anterior surgical decompression and ostheosynthesis. Intervertebral disc herniation was present in nine of the patients, and ruptured calcified posterior longitudinal ligament

  3. Faceted Ranking of Egos in Collaborative Tagging Systems Jose I. Orlicki(1,2)

    E-print Network

    Paris-Sud XI, Université de

    Faceted Ranking of Egos in Collaborative Tagging Systems Jose I. Orlicki(1,2) , Pablo I. Fierens(2 as folksonomies. Faceted web ranking has been proved a reasonable alternative to a single ranking which does not take into account a personalized context. In this paper we analyze the online computation of rankings

  4. Facile synthesis of AgBr nanoplates with exposed {111} facets and enhanced photocatalytic properties.

    PubMed

    Wang, Hua; Gao, Jian; Guo, Tianqi; Wang, Rongming; Guo, Lin; Liu, Yang; Li, Jinghong

    2012-01-01

    AgBr nanoplates with exposed {111} facets have been synthesized in high yield by a facile precipitation reaction, and the as-prepared nanoplates exhibited greatly enhanced photocatalytic properties for the degradation of organic pollutants, which may be primarily ascribed to the relatively higher surface energy of {111} facets. PMID:22105717

  5. Scattering from long prisms computed using ray tracing combined with diffraction on facets

    Microsoft Academic Search

    Evelyn Hesse; Zbigniew Ulanowski

    2003-01-01

    A new model suitable for rapid computation of scattering on faceted dielectric objects such as ice crystals is presented. It combines ray tracing with diffraction on flat facets. The model allows retaining the ray nature of the internal field by calculating the diffraction component using an approximation for the far field direction of the Poynting vector. While this approach is

  6. Nitrogen-induced reconstruction and faceting of Re(112{sup ¯}1)

    SciTech Connect

    Wang, Hao; Chen, Wenhua; Bartynski, Robert A. [Department of Physics and Astronomy and Laboratory for Surface Modification, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854 (United States)] [Department of Physics and Astronomy and Laboratory for Surface Modification, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854 (United States); Kaghazchi, Payam; Jacob, Timo [Institute of Electrochemistry, Ulm University, Albert-Einstein-Allee 47, D-89069 Ulm (Germany)] [Institute of Electrochemistry, Ulm University, Albert-Einstein-Allee 47, D-89069 Ulm (Germany)

    2014-01-14

    The surface morphology of Re(112{sup ¯}1), tailored on the nanometer scale by kinetic control of nitrogen, has been investigated using low energy electron diffraction, scanning tunneling microscopy, Auger electron spectroscopy, and density functional theory (DFT) in combination with the ab initio atomistic thermodynamics approach. Experiments show that when exposing to NH{sub 3} (>0.5 L) at 300 K followed by annealing in ultra-high vacuum at 700 K or 900 K, the initially planar Re(112{sup ¯}1) surface becomes (2 × 1) reconstructed or partially faceted, respectively. Upon annealing in 100 L NH{sub 3} at 900 K, Re(112{sup ¯}1) becomes fully faceted and covered by N. The fully faceted surface consists of two-sided ridges formed by (134{sup ¯}2) and (314{sup ¯}2) facets. The (2 × 1) reconstruction may serve as a precursor state for faceting of Re(112{sup ¯}1). The DFT calculations provide an atomistic understanding of facet formation in terms of binding sites and energies of N on Re surfaces of the substrate and facets as well as the corresponding surface phase diagram. The N-covered faceted Re(112{sup ¯}1) surfaces are promising nanoscale model catalysts and nanotemplates. Our findings should be of importance for the design and development of Re-based heterogeneous catalysts operating under nitrogen-rich conditions.

  7. An experimental approach to evaluate the correspondence between wear facet position and occlusal movements.

    PubMed

    Kullmer, Ottmar; Schulz, Dieter; Benazzi, Stefano

    2012-05-01

    The position of dental wear facets depends on crown morphology, antagonistic relation, and occlusal movements. The correspondence between specific directions of movements and the position of wear facets cannot be easily evaluated in vivo and has never been tested experimentally. An experimental analysis was carried out to provide evidence that explicit occlusal movements are responsible for the spatial position of wears facets. Unworn dental stone replicas of modern human prosthetic molar were mounted in a physical dental articulator, and the upper dental arch was ground against the lowers to create a wear facet pattern. The relief guided movements were constrained sequentially by means of three different condyle box setups: (1) experienced-based mean values for sagittal condyle inclination, lateroretrusion, Benett angle, and transversal condyle inclination were used; (2) pure retrusion and immediate side shift movements were added; (3) retrusion and immediate side shift were increased. Finally, the upper and lower first molars were surface scanned and macrowear facets were quantified in four wear stages. The results show that a wear facet pattern was created similar to what is seen on human molars in vivo occlusion. Some facets only developed if specific directions of movement were carried out. Therefore, we posit that an analysis of wear facet patterns is useful in recreating the individual occlusal movements. This information can be used not only to guide reproducible functional reconstructions of crown relief and dental arches but also to deduce jaw movements when, for example, isolated primate teeth are discovered in paleontological contexts. PMID:22419654

  8. Faceted Taxonomy-based Information Management Yannis Tzitzikas1,2

    E-print Network

    Tzitzikas, Yannis

    Faceted Taxonomy-based Information Management Yannis Tzitzikas1,2 and Anastasia Analyti2 1) taxonomy-based information sources. Specifically, we discuss (i) the semantic descrip- tion of faceted taxonomies, based on the Compound Term Composition Algebra (CTCA), (ii) the revision of CTCA ex- pressions

  9. Factors Influencing the Success of Organizational Learning Implementation: A Policy Facet Perspective

    Microsoft Academic Search

    G. Stephen Taylor; Gary F. Templeton; LaKami T. Baker

    2010-01-01

    Despite a cumulative tradition of over 50 years, the organizational learning (OL) literature contains very little research on its implementation into practice. Because OL is a multidisciplinary topic and consequently has a myriad of diverse definitions, research on getting organizational members to adopt its tenets has been scarce. Using the policy facet of the theoretical multi-faceted model (MFM) of OL,

  10. Testing of the SAIC facets on the stretched-membrane dish

    NASA Astrophysics Data System (ADS)

    Grossman, J. W.; Erdman, W. W.; Houser, R. M.; Davenport, R.

    1994-04-01

    A dish structure sized for a 25 kW electric dish/generator system has been installed at the National Solar Thermal Test Facility (NSTTF). The dish is used as an optical test bed for prototype stretched-membrane facets. Sandia procured twelve (12) stretched-membrane facets from Science Applications International Corporation (SAIC) for installation on the dish structure. Individual facet optical performance was measured using the 2f test method under development at Sandia. Four facets were tested on-sun using the test truss at the NSTTF prior to installation on the dish structure. During the final stages of the structure assembly, the facets were installed for testing. A distant light source alignment technique was used to align the facets to a 9 meter focal length. The alignment and focus were optimized with on-sun measurements of individual facet characteristics. On-sun flux maps of the image were made using the Beam Characterization System. Calorimetry tests were performed using a cold water calorimeter. This data was used to create a power intercept curve and predict the power inside apertures of different sizes. The focal plane was moved to 9.95 meters and the alignment, optimization, and on-sun tests repeated. This paper presents the results of the testing on the individual facets as well as the results of testing the dish system. The effects of the change in focal length on the optical performance of the dish are shown in the results.

  11. Testing of the SAIC facets on the stretched-membrane dish

    SciTech Connect

    Grossman, J.W.; Erdman, W.W.; Houser, R.M. [Sandia National Labs., Albuquerque, NM (United States); Davenport, R.L. [Science Applications International Corp., Golden, CO (United States)

    1995-11-01

    A dish structure sized for a 25 kW electric dish/generator system has been installed at the National Solar Thermal Test Facility (NSTTF). The dish is used as an optical test bed for prototype stretched-membrane facets. Sandia procured twelve (12) stretched-membrane facets from Science Applications International Corporation (SAIC) for installation on the dish structure. Individual facet optical performance was measured using the 2f test method under development at Sandia. Four facets were tested on-sun using the test truss at the NSTTF prior to installation on the dish structure. During the final stages of the structure assembly, the facets were installed for testing. A distant light source alignment technique was used to align the facets to a 9 meter focal length. The alignment and focus were optimized with on-sun measurements of individual facet characteristics. On-sun flux maps of the image were made using the Beam Characterization System. Calorimetry tests were performed using a cold water calorimeter. This data was used to create a power intercept curve and predict the power inside apertures of different sizes. The focal plane was moved to 9.95 meters and the alignment, optimization, and on-sun tests were repeated. This paper presents the results of the testing on the individual facets as well as the results of testing the dish system. Improvements in optical performance of the dish from the change in focal length are shown in the results.

  12. Global Self-Esteem: Its Relation to Weighted Averages of Specific Facets of Self-Concept.

    ERIC Educational Resources Information Center

    Marsh, Herbert W.

    Theory and common sense posit that the effect of a specific facet of self-concept on Global Esteem will vary with the importance placed on that facet, but no support for this interactive hypothesis was found. Unweighted averages of 12 distinct dimensions of self-concept from the Self Description Questionnaire III correlated about .7 with Global…

  13. FACETS Report for Jan-May, 2007 1. Project summary and management

    E-print Network

    1 FACETS Report for Jan-May, 2007 1. Project summary and management The FACETS project/O is done through an abstract API that is independent of the actual underlying library used. A concrete that prevents circular dependencies. A component/coupler system allows coupled multi-physics simulations. Each

  14. The Importance of Conveying Inter-Facet Relationships for Making Sense of Unfamiliar Domains

    Microsoft Academic Search

    Max L. Wilson

    The design of online retail environments has improved significantly by including features such as faceted navigation, which provide meta-data to users as a means to apply constraints over the available products. The position held in this paper, and supported by a growing body of evidence, is that the specific implementation of such faceted experiences can increase the support for more

  15. Measured and predicted root-mean-square errors in square and triangular antenna mesh facets

    NASA Technical Reports Server (NTRS)

    Fichter, W. B.

    1989-01-01

    Deflection shapes of square and equilateral triangular facets of two tricot-knit, gold plated molybdenum wire mesh antenna materials were measured and compared, on the basis of root mean square (rms) differences, with deflection shapes predicted by linear membrane theory, for several cases of biaxial mesh tension. The two mesh materials contained approximately 10 and 16 holes per linear inch, measured diagonally with respect to the course and wale directions. The deflection measurement system employed a non-contact eddy current proximity probe and an electromagnetic distance sensing probe in conjunction with a precision optical level. Despite experimental uncertainties, rms differences between measured and predicted deflection shapes suggest the following conclusions: that replacing flat antenna facets with facets conforming to parabolically curved structural members yields smaller rms surface error; that potential accuracy gains are greater for equilateral triangular facets than for square facets; and that linear membrane theory can be a useful tool in the design of tricot knit wire mesh antennas.

  16. Quantum cascade lasers with a tilted facet utilizing the inherent polarization purity.

    PubMed

    Ahn, Sangil; Ristanic, Daniela; Gansch, Roman; Reininger, Peter; Schwarzer, Clemens; MacFarland, Donald C; Detz, Hermann; Schrenk, Werner; Strasser, Gottfried

    2014-10-20

    We report on quantum cascade lasers (QCLs) with a tilted facet utilizing their polarization property. Contrary to diode lasers, QCLs generate purely TM polarized light due to the intersubband selection rules. This property enables the utilization of reflectivity in terms of only TM polarized light (TM reflectivity). The TM reflectivity is reduced by tilting the front facet, resulting in enhanced light output power from the tilted facet. The peak output power of a QCL with a facet angle of 12° are increased by 31 %. The slope efficiency of a QCL with a facet angle of 17° are increased by 43 %. Additionally, a peculiar property of TM reflectivity, the Brewster angle, is investigated by using COMSOL simulations to find its availability in QCLs. PMID:25401662

  17. Facet-dependent catalytic activity of MnO electrocatalysts for oxygen reduction and oxygen evolution reactions.

    PubMed

    Kuo, Chung-Hao; Mosa, Islam M; Thanneeru, Srinivas; Sharma, Vinit; Zhang, Lichun; Biswas, Sourav; Aindow, Mark; Pamir Alpay, S; Rusling, James F; Suib, Steven L; He, Jie

    2015-04-01

    This Communication highlights the facet-dependent electrocatalytic activity of MnO nanocrystals for OERs/ORRs. The MnO(100) facets with higher adsorption energy of O species can largely promote the electrocatalytic activity. PMID:25736247

  18. Friction in Total Hip Joint Prosthesis Measured In Vivo during Walking

    PubMed Central

    Damm, Philipp; Dymke, Joern; Ackermann, Robert; Bender, Alwina; Graichen, Friedmar; Halder, Andreas; Beier, Alexander; Bergmann, Georg

    2013-01-01

    Friction-induced moments and subsequent cup loosening can be the reason for total hip joint replacement failure. The aim of this study was to measure the in vivo contact forces and friction moments during walking. Instrumented hip implants with Al2O3 ceramic head and an XPE inlay were used. In vivo measurements were taken 3 months post operatively in 8 subjects. The coefficient of friction was calculated in 3D throughout the whole gait cycle, and average values of the friction-induced power dissipation in the joint were determined. On average, peak contact forces of 248% of the bodyweight and peak friction moments of 0.26% bodyweight times meter were determined. However, contact forces and friction moments varied greatly between individuals. The friction moment increased during the extension phase of the joint. The average coefficient of friction also increased during this period, from 0.04 (0.03 to 0.06) at contralateral toe off to 0.06 (0.04 to 0.08) at contralateral heel strike. During the flexion phase, the coefficient of friction increased further to 0.14 (0.09 to 0.23) at toe off. The average friction-induced power throughout the whole gait cycle was 2.3 W (1.4 W to 3.8 W). Although more parameters than only the synovia determine the friction, the wide ranges of friction coefficients and power dissipation indicate that the lubricating properties of synovia are individually very different. However, such differences may also exist in natural joints and may influence the progression of arthrosis. Furthermore, subjects with very high power dissipation may be at risk of thermally induced implant loosening. The large increase of the friction coefficient during each step could be caused by the synovia being squeezed out under load. PMID:24260114

  19. Joint Instability and Osteoarthritis

    PubMed Central

    Blalock, Darryl; Miller, Andrew; Tilley, Michael; Wang, Jinxi

    2015-01-01

    Joint instability creates a clinical and economic burden in the health care system. Injuries and disorders that directly damage the joint structure or lead to joint instability are highly associated with osteoarthritis (OA). Thus, understanding the physiology of joint stability and the mechanisms of joint instability-induced OA is of clinical significance. The first section of this review discusses the structure and function of major joint tissues, including periarticular muscles, which play a significant role in joint stability. Because the knee, ankle, and shoulder joints demonstrate a high incidence of ligament injury and joint instability, the second section summarizes the mechanisms of ligament injury-associated joint instability of these joints. The final section highlights the recent advances in the understanding of the mechanical and biological mechanisms of joint instability-induced OA. These advances may lead to new opportunities for clinical intervention in the prevention and early treatment of OA. PMID:25741184

  20. Obtaining Content Weights for Test Specifications from Job Analysis Task Surveys: An Application of the Many-Facets Rasch Model

    ERIC Educational Resources Information Center

    Wang, Ning; Stahl, John

    2012-01-01

    This article discusses the use of the Many-Facets Rasch Model, via the FACETS computer program (Linacre, 2006a), to scale job/practice analysis survey data as well as to combine multiple rating scales into single composite weights representing the tasks' relative importance. Results from the Many-Facets Rasch Model are compared with those…

  1. Temperature-Sensitive Mutations in Drosophila melanogaster, IV. A Mutation Affecting Eye Facet Arrangement in a Polarized Manner

    Microsoft Academic Search

    Geoffrey G. Foster; David T. Suzuki

    1970-01-01

    Drosophila melanogaster females heterozygous for the mutation N60g11 have wild type eyes when raised at 29 degrees C but a disrupted arrangement of facets and extra bristles at 21 degrees C. Shifts of cultures from one temperature to the other at different stages in development revealed that facet arrangement is altered by temperature during the third larval instar. The facet

  2. Improving Personality Facet Scores with Multidimensional Computer Adaptive Testing: An Illustration with the Neo Pi-R

    ERIC Educational Resources Information Center

    Makransky, Guido; Mortensen, Erik Lykke; Glas, Cees A. W.

    2013-01-01

    Narrowly defined personality facet scores are commonly reported and used for making decisions in clinical and organizational settings. Although these facets are typically related, scoring is usually carried out for a single facet at a time. This method can be ineffective and time consuming when personality tests contain many highly correlated…

  3. Thermal and shape stability of high-index-faceted rhodium nanoparticles: a molecular dynamics investigation.

    PubMed

    Zeng, Xiang-Ming; Huang, Rao; Wen, Yu-Hua; Sun, Shi-Gang

    2015-02-28

    Nanosized noble metallic particles enclosed by high-index facets exhibit superior catalytic activity because of their high density of low-coordinated step atoms at the surface, and thus have attracted growing interest over the past decade. In this article, we employed molecular dynamics simulations to investigate the thermodynamic evolution of tetrahexahedral Rh nanoparticles respectively covered by {210}, {310}, and {830} facets during the heating process. Our results reveal that the {210} faceted nanoparticle exhibits better thermal and shape stability than the {310} and {830} faceted ones. Meanwhile, because the {830} facet consists of {210} and {310} subfacets, the stability of the {830} faceted Rh nanoparticle is dominated by the {310} subfacet, which possesses a relatively poor stability. Furthermore, the shape transformation of these nanoparticles occurs much earlier than their melting. Further analyses indicate that surface atoms with higher coordination numbers display lower surface diffusivity, and are thus more helpful for stabilizing the particle shape. This study offers an atomistic understanding of the thermodynamic behaviors of high-index-faceted Rh nanoparticles. PMID:25628229

  4. Specific oriented metal-organic framework membranes and their facet-tuned separation performance.

    PubMed

    Mao, Yiyin; Su, Binbin; Cao, Wei; Li, Junwei; Ying, Yulong; Ying, Wen; Hou, Yajun; Sun, Luwei; Peng, Xinsheng

    2014-09-24

    Modulating the crystal morphology, or the exposed crystal facets, of metal-organic frameworks (MOFs) expands their potential applications in catalysis, adsorption, and separation. In this article, by immobilizing the citrate modulators on Au nanoparticles and subsequently being fixed on solid copper hydroxide nanostrands, a well-intergrown and oriented HKUST-1 cube crystal membrane was formed at room temperature. In contrast, in the absence of Au nanoparticles, well-intergrown and oriented cuboctahedron and octahedron membranes were formed in water/ethanol and ethanol, respectively. The gas separation performances of these HKUST-1 membranes were tuned via their exposed facets with defined pore sizes. The HKUST-1 cube membrane with exposed {001} facets demonstrated the highest permeance but lowest gas binary separation factors, while the octahedron membrane with exposed {111} facets presented the highest separation factors but lowest permeance, since the window size of {111} facets is 0.46 nm which is smaller than 0.9 nm of {001} facets. Separation of 0.38 nm CO2 from 0.55 nm SF6 was realized by the HKUST-1 octahedron membrane. As a proof of concept, this will open a new way to design MOF-related separation membranes by facet controlling. PMID:25184955

  5. Treatment-related changes in behavioral outcomes of psychopathy facets in adolescent offenders.

    PubMed

    Caldwell, Michael F

    2011-08-01

    This study examines the association between the facets of psychopathy embedded in the Psychopathy Checklist: Youth Version (PCL:YV; Forth et al., Psychopathy Checklist: Youth Version, 2003), and changes in institutional behavior and post-treatment violent and general offending in a sample of juvenile delinquent males treated in the Mendota Juvenile Treatment Center (MJTC), an intensive treatment program. Affective, Interpersonal, Behavioral and Antisocial facet scale scores were calculated from items of the Psychopathy Checklist: Youth Version (PCL:YV; Forth et al., 2003). Data on daily institutional behavior were collected from treatment records. In order to analyze re-offense patterns, the number and type of new criminal charges were collected over a mean follow-up of 54 months (range = 24-79 months), after the youth was released from custody. The Interpersonal facet of the PCL:YV was significantly related to admission behavior problems, while other facet scores were not. Youth with elevated Interpersonal facet scores showed the greatest improvement in institutional behavior during treatment. Treatment was also associated with a significant decrease in general and violent offending for each facet. The Interpersonal facet of the PCL:YV was found to play a key role in institutional and community violence in this study. Treatment appeared to disrupt the link between institutional and community violence and psychopathy features in this population. PMID:20658262

  6. Facility for Advanced Accelerator Experimental Tests at SLAC (FACET) Conceptual Design Report

    SciTech Connect

    Amann, J.; Bane, K.; /SLAC

    2009-10-30

    This Conceptual Design Report (CDR) describes the design of FACET. It will be updated to stay current with the developing design of the facility. This CDR begins as the baseline conceptual design and will evolve into an 'as-built' manual for the completed facility. The Executive Summary, Chapter 1, gives an introduction to the FACET project and describes the salient features of its design. Chapter 2 gives an overview of FACET. It describes the general parameters of the machine and the basic approaches to implementation. The FACET project does not include the implementation of specific scientific experiments either for plasma wake-field acceleration for other applications. Nonetheless, enough work has been done to define potential experiments to assure that the facility can meet the requirements of the experimental community. Chapter 3, Scientific Case, describes the planned plasma wakefield and other experiments. Chapter 4, Technical Description of FACET, describes the parameters and design of all technical systems of FACET. FACET uses the first two thirds of the existing SLAC linac to accelerate the beam to about 20GeV, and compress it with the aid of two chicanes, located in Sector 10 and Sector 20. The Sector 20 area will include a focusing system, the generic experimental area and the beam dump. Chapter 5, Management of Scientific Program, describes the management of the scientific program at FACET. Chapter 6, Environment, Safety and Health and Quality Assurance, describes the existing programs at SLAC and their application to the FACET project. It includes a preliminary analysis of safety hazards and the planned mitigation. Chapter 7, Work Breakdown Structure, describes the structure used for developing the cost estimates, which will also be used to manage the project. The chapter defines the scope of work of each element down to level 3.

  7. The many facets of PPAR?: novel insights for the skeleton

    PubMed Central

    Kawai, Masanobu; Sousa, Kyle M.; MacDougald, Ormond A.

    2010-01-01

    Peroxisome proliferator-activated receptor-? (PPAR?) is a nuclear receptor that functions as a master transcriptional regulator of adipocyte conversion. During PPAR? transactivation, multiple signaling pathways interact with one another, leading to the differentiation of both white and brown adipose tissue. Ligand activation of the PPAR?-RXR heterodimer complex also enhances insulin sensitivity, and this property has been heavily exploited to develop effective pharmacotherapies for the treatment of type 2 diabetes mellitus. PPAR? is also expressed in stem cells and plays a critical role in mesenchymal stromal cell differentiation and lineage determination events. The many facets of PPAR? activity within the bone marrow niche where adipocytes, osteoblasts, and hematopoietic cells reside make this molecule an attractive target for pharmacological investigation. Additional findings that osteoblasts can alter energy metabolism by influencing adiposity and insulin sensitivity, and observations of decreased bone turnover in diabetic subjects, underscore the contribution of the skeleton to systemic energy requirements. Studies into the role of PPAR? in skeletal acquisition and maintenance may lead to a better understanding of the molecular mechanisms governing stromal cell differentiation in the mesenchyme compartment and whether PPAR? activity can be manipulated to benefit skeletal remodeling events and energy metabolism. PMID:20407009

  8. The experimental-numerical investigation of instability of faceted Ge doped by Sb growth on the base of AHP method

    NASA Astrophysics Data System (ADS)

    Bykova, Sveta V.; Golyshev, Vladimir D.; Gonik, Michael A.; Tsvetovsky, Vladimir B.; Balikci, Ercan; Deal, Andrew; Abbaschian, Reza; Marchenko, Marina P.; Frjazinov, Igor. V.; Vlasov, Vladimir N.; Serebrjakov, Jury A.

    2005-02-01

    An antimony-doped germanium single crystal was grown by the Axial Heat Processing (AHP) method from the melt to study the influence of facets on the morphological stability of a solid/liquid interface. It is shown that the faceted portion of the interface remains more stable than the non-faceted portion. In addition, instability of the faceted region occurs at a higher solute concentration with larger cell spacing. A mathematical model, accounting for the presence of facet, predicted the solute profile and morphological features of the grown crystal are in good agreement with the experimental data.

  9. Proprioception and joint stability

    Microsoft Academic Search

    J. Jerosch; M. Prymka

    1996-01-01

    In the present paper the current clinical knowledge about proprioception is given for the shoulder, knee, ankle, elbow and the radiocarpal joint. Proprioceptive capabilities are decreased after joint injuries such as ACL or meniscus tears, shoulder dislocation, ankle sprain and in joints with degenerative joint disease. Some surgical procedures seem to restore the proprioceptive abilities; others do not. Elastic knee

  10. Joint Infection (Beyond the Basics)

    MedlinePLUS

    ... Infection of an artificial joint is known as prosthetic joint infection. GONOCOCCAL JOINT INFECTION Gonococcal joint infection ... cases, it is not possible to replace the prosthetic joint, and surgery to fuse the bones is ...

  11. Effects of CeO2 Support Facets on VOx/CeO2 Catalysts in Oxidative Dehydrogenation of Methanol

    SciTech Connect

    Li, Yan; Wei, Zhehao; Gao, Feng; Kovarik, Libor; Peden, Charles HF; Wang, Yong

    2014-05-13

    CeO2 supports with dominating facets, i.e., low index (100), (110) and (111) facets, are prepared. The facet effects on the structure and catalytic performance of supported vanadium oxide catalysts are investigated using oxidative dehydrogenation of methanol as a model reaction. In the presence of mixed facets, Infrared and Raman characterizations demonstrate that surface vanadia species preferentially deposit on CeO2 (100) facets, presumably because of its higher surface energy. At the same surface vanadium densities, VOx species on (100) facets show better dispersion, followed by (110) and (111) facets. The VOx species on CeO2 nanorods with (110) and (100) facets display higher activity and lower apparent activation energies compared to that on CeO2 nanopolyhedras with dominating (111) facets and CeO2 nanocubes with dominating (100) facets. The higher activity for VOx/CeO2(110) might be related to the more abundant oxygen vacancies present on the (110) facets, evidenced from Raman spectroscopic measurements.

  12. Facet-dependent electrochemical properties of Co3O4 nanocrystals toward heavy metal ions

    PubMed Central

    Yu, Xin-Yao; Meng, Qiang-Qiang; Luo, Tao; Jia, Yong; Sun, Bai; Li, Qun-Xiang; Liu, Jin-Huai; Huang, Xing-Jiu

    2013-01-01

    We revealed an interesting facet-dependent electrochemical behavior toward heavy metal ions (HMIs) based on their adsorption behaviors. The (111) facet of Co3O4 nanoplates has better electrochemical sensing performance than that of the (001) facet of Co3O4 nanocubes. Adsorption measurements and density-functional theory (DFT) calculations reveals that adsorption of HMIs is responsible for the difference of electrochemical properties. Our combined experimental and theoretical studies provide a solid hint to explain the mechanism of electrochemical detection of HMIs using nanoscale metal oxides. Furthermore, this study not only suggests a promising new strategy for designing high performance electrochemical sensing interface through the selective synthesis of nanoscale materials exposed with different well-defined facets, but also provides a deep understanding for a more sensitive and selective electroanalysis at nanomaterials modified electrodes. PMID:24097175

  13. Organizational culture, creative behavior, and information and communication technology (ICT) usage: a facet analysis.

    PubMed

    Carmeli, Abraham; Sternberg, Akiva; Elizur, D

    2008-04-01

    Despite the prominence of organizational culture (OC), this concept is controversial and its structure has yet to be systematically analyzed. This study develops a three-pronged formal definitional framework on the basis of facet theory (FT) and explores behavior modality, referent, and object. This facet analysis (FA) of OC accounts successfully for variation in both creative behavior at work and the usage of information and communication technologies (ICTs). An analysis of data collected from 230 employees in the financial industry indicates that a radex structure was obtained for work and ICT. The behavior modality facet ordered the space from center to periphery, and referents facet relates to the direction angles away from the origin. PMID:18422410

  14. Consensually Defined Facets of Personality as Prospective Predictors of Change in Depression Symptoms.

    PubMed

    Naragon-Gainey, Kristin; Watson, David

    2014-03-26

    Depression has robust associations with personality, showing a strong relation with neuroticism and more moderate associations with extraversion and conscientiousness. In addition, each Big Five domain can be decomposed into narrower facets. However, we currently lack consensus as to the contents of Big Five facets, with idiosyncrasies across instruments; moreover, few studies have examined associations with depression. In the current study, community participants completed six omnibus personality inventories; self-reported depressive symptoms were assessed at baseline and 5 years later. Exploratory factor analyses suggested three to five facets in each domain, and these facets served as prospective predictors of depression in hierarchical regressions, after accounting for baseline and trait depression. In these analyses, high anger (from neuroticism), low positive emotionality (extraversion), low conventionality (conscientiousness), and low culture (openness to experiences) were significant prospective predictors of depression. Results are discussed in regard to personality structure and assessment, as well as personality-psychopathology associations. PMID:24671734

  15. Openness to Experience and Mortality in Men: Analysis of Trait and Facets

    PubMed Central

    Turiano, Nicholas A.; Spiro, Avron; Mroczek, Daniel K.

    2013-01-01

    Objectives We examined whether specific facets are more robust predictors of mortality risk than overall trait openness in a sample of older men. Methods The current investigation used data from 1,349 men from the Veterans Affairs Normative Aging Study. From 1990–1991 to 2008, 547 (41%) had died. We used exploratory factor analysis to extract facets of openness, followed by proportional hazards modeling to examine 18-year mortality risk. Results Two facets emerged from the openness adjectives: intellect and creativity. In the fully adjusted model, only creativity predicted mortality risk. A 1-SD increase in creativity was associated with a 12% decrease in mortality risk. Discussion The study demonstrated that consideration of facets allows for a more precise understanding of the personality–health association. Higher levels of creativity predict longer survival in a sample of older men which provides preliminary support of the protective role creativity has on health even at advanced ages. PMID:22219209

  16. Facet-Specific Assembly of Proteins on SrTiO3 Polyhedral Nanocrystals

    NASA Astrophysics Data System (ADS)

    Dong, Lingqing; Luo, Qi; Cheng, Kui; Shi, Hui; Wang, Qi; Weng, Wenjian; Han, Wei-Qiang

    2014-05-01

    Precisely controlling the protein-nanomaterial interactions at selective sites is crucial in engineering biomolecule composite architectures with tailored nanostructures and functions for a variety of biomedical applications. This strategy, however, is only beginning to be explored. Here, we demonstrate the facet-specific assembly of proteins, such as albumin, immunoglobulin and protamine, on {100} facets of SrTiO3 polyhedral nanocrystals, while none on {110} facets. Molecular dynamics simulations indicate the immobile surface hydration layer might play a barrier role to effectively prevent proteins adsorption on specific {110} facets. This work thus provides new insights into the fundamentally understanding of protein-nanomaterial interactions, and open a novel, general and facile route to control the selective adsorption of various proteins on various nanocrystals.

  17. Sparsely Faceted Arrays: A Mechanism Supporting Parallel Allocation, Communication, and Garbage Collection

    E-print Network

    Brown, Jeremy Hanford

    2002-06-01

    Conventional parallel computer architectures do not provide support for non-uniformly distributed objects. In this thesis, I introduce sparsely faceted arrays (SFAs), a new low-level mechanism for naming regions of memory, ...

  18. Sparsely faceted arrays : a mechanism supporting the parallel allocation, communication, and garbage collection

    E-print Network

    Brown, Jeremy Hanford, 1972-

    2002-01-01

    Conventional parallel computer architectures do not provide support for non-uniformly distributed objects. In this thesis, I introduce sparsely faceted arrays (SFAs), a new low-level mechanism for naming regions of memory, ...

  19. Crystal-facet-dependent metallization in electrolyte-gated rutile TiO2 single crystals.

    PubMed

    Schladt, Thomas D; Graf, Tanja; Aetukuri, Nagaphani B; Li, Mingyang; Fantini, Andrea; Jiang, Xin; Samant, Mahesh G; Parkin, Stuart S P

    2013-09-24

    The electric-field-induced metallization of insulating oxides is a powerful means of exploring and creating exotic electronic states. Here we show by the use of ionic liquid gating that two distinct facets of rutile TiO2, namely, (101) and (001), show clear evidence of metallization, with a disorder-induced metal-insulator transition at low temperatures, whereas two other facets, (110) and (100), show no substantial effects. This facet-dependent metallization can be correlated with the surface energy of the respective crystal facet and, thus, is consistent with oxygen vacancy formation and diffusion that results from the electric fields generated within the electric double layers at the ionic liquid/TiO2 interface. These effects take place at even relatively modest gate voltages. PMID:23962081

  20. Domains and Facets: Hierarchical Personality Assessment Using the Revised NEO Personality Inventory

    Microsoft Academic Search

    Paul T. Costa; Robert R. McCrae

    1995-01-01

    Personality traits are organized hierarchically, with narrow, specific traits com- bining to define broad, global factors. The Revised NEO Personality Inventory (NEO-PI-R; Costa & McCrae, 1992c) assesses personality at bo1.h levels, with six specific facet scales in each of five broad domains. This article describes conceptual issues in specifying facets of a domain and reports evidence on the validity of

  1. The Five Facet Mindfulness Questionnaire: Psychometric Properties of the Chinese Version

    Microsoft Academic Search

    Yu-Qin Deng; Xing-Hua Liu; Marcus A. Rodriguez; Chun-Yan Xia

    2011-01-01

    We investigated the psychometric properties of a Chinese version of Five Facet Mindfulness Questionnaire (FFMQ) in a non-clinical\\u000a student sample. The Chinese FFMQ demonstrated acceptable internal consistency and the test-retest reliability. Confirmatory\\u000a factor analysis provided support for the five-factor model. Four of these facets (describing, acting with awareness, non-judging\\u000a and non-reacting) were shown to have incremental validity in the prediction

  2. Plasma Wakefield Acceleration and FACET - Facilities for Accelerator Science and Experimental Test Beams at SLAC

    ScienceCinema

    Andrei Seryi

    2010-01-08

    Plasma wakefield acceleration is one of the most promising approaches to advancing accelerator technology. This approach offers a potential 1,000-fold or more increase in acceleration over a given distance, compared to existing accelerators.  FACET, enabled by the Recovery Act funds, will study plasma acceleration, using short, intense pulses of electrons and positrons. In this lecture, the physics of plasma acceleration and features of FACET will be presented.  

  3. Fabrication of dry etched and subsequently passivated laser facets in GaAs/AlGaAs

    SciTech Connect

    Deichsel, Eckard; Franz, Gerhard [University of Ulm, Ulm, Germany and Swiss Federal Institute of Technology, Lausanne (Switzerland); Munich University of Applied Sciences, Munich, Bavaria (Germany)

    2004-09-01

    The aging behavior of edge emitting laser diodes based on GaAs/AlGaAs is investigated by comparing devices with facets that are alternatively cleaved or dry etched and consecutively treated with H{sub 2}S. In this work we demonstrate that an in situ exposure to H{sub 2}S gas is not sufficient to prevent ageing but an additional plasma treatment is rather required to obtain comparable ageing results to lasers with cleaved facets.

  4. Computing deep facet-defining disjunctive cuts for mixed-integer programming

    Microsoft Academic Search

    Florent Cadoux

    2010-01-01

    The problem of separation is to find an affine hyperplane, or “cut”, that lies between the origin O and a given closed convex set Q in a Euclidean space. We study cuts which are deep in a well-defined geometrical sense, and facet-defining. The cases when\\u000a the deepest cut is decomposable as a combination of facet-defining cuts are characterized using the

  5. Facet Model and Mathematical Morphology for Surface Characterization

    SciTech Connect

    Abidi, B.R.; Goddard, J.S.; Hunt, M.A.; Sari-Sarraf, H.

    1999-11-13

    This paper describes an algorithm for the automatic segmentation and representation of surface structures and non-uniformities in an industrial setting. The automatic image processing and analysis algorithm is developed as part of a complete on-line web characterization system of a papermaking process at the wet end. The goal is to: (1) link certain types of structures on the surface of the web to known machine parameter values, and (2) find the connection between detected structures at the beginning of the line and defects seen on the final product. Images of the pulp mixture (slurry), carried by a fast moving table, are obtained using a stroboscopic light and a CCD camera. This characterization algorithm succeeded where conventional contrast and edge detection techniques failed due to a poorly controlled environment. The images obtained have poor contrast and contain noise caused by a variety of sources. After a number of enhancement steps, conventional segmentation methods still f ailed to detect any structures and are consequently discarded. Techniques tried include the Canny edge detector, the Sobel, Roberts, and Prewitt's filters, as well as zero crossings. The facet model algorithm, is then applied to the images with various parameter settings and is found to be successful in detecting the various topographic characteristics of the surface of the slurry. Pertinent topographic elements are retained and a filtered image computed. Carefully tailored morphological operators are then applied to detect and segment regions of interest. Those regions are then selected according to their size, elongation, and orientation. Their bounding rectangles are computed and represented. Also addressed in this paper are aspects of the real time implementation of this algorithm for on-line use. The algorithm is tested on over 500 images of slurry and is found to segment and characterize nonuniformities on all 500 images.

  6. Variations of anatomical elements contributing to subtalar joint stability: intrinsic risk factors for post-traumatic lateral instability of the ankle?

    PubMed

    Barbaix, E; Van Roy, P; Clarys, J P

    2000-10-01

    Ankle sprains are frequently followed by chronic lateral instability, often with talar hypermobility. This might be due to subtalar instability. Among intrinsic risk factors, anatomical variants are generally overlooked. In the subtalar region, anatomical variation is particularly frequent. On the talus as well as on the calcaneus, the anterior articular facets may be missing or fused with the medial facets, giving rise to three subtalar joint configurations: a three-joint configuration, a fused configuration with a relatively large anteromedial joint, and a two-joint configuration without anterior joint. Osteometry was performed on these joint facets (134 calcanei, 122 tali), demonstrating significant differences in the surface of these configurations and the existence of a supplementary supporting surface with grossly transverse orientation in the three-joint configuration. There are also several variants of stabilizing ligaments within the sinus tarsi. Some of these configurations might expose to increased risk of associated subtalar lesions, resulting in subtalar instability. A systematic look for these variants is recommended in order to evaluate the associated risk factors, eventually resulting in a better understanding, prevention and cure of sequellae. PMID:11083150

  7. Butt Joint Tool Commissioning

    SciTech Connect

    Martovetsky, N N

    2007-12-06

    ITER Central Solenoid uses butt joints for connecting the pancakes in the CS module. The principles of the butt joining of the CICC were developed by the JAPT during CSMC project. The difference between the CSMC butt joint and the CS butt joint is that the CS butt joint is an in-line joint, while the CSMC is a double joint through a hairpin jumper. The CS butt joint has to carry the hoop load. The straight length of the joint is only 320 mm, and the vacuum chamber around the joint has to have a split in the clamp shell. These requirements are challenging. Fig.1 presents a CSMC joint, and Fig.2 shows a CS butt joint. The butt joint procedure was verified and demonstrated. The tool is capable of achieving all specified parameters. The vacuum in the end was a little higher than the target, which is not critical and readily correctable. We consider, tentatively that the procedure is established. Unexpectedly, we discover significant temperature nonuniformity in the joint cross section, which is not formally a violation of the specs, but is a point of concern. All testing parameters are recorded for QA purposes. We plan to modify the butt joining tool to improve its convenience of operation and provide all features necessary for production of butt joints by qualified personnel.

  8. Epitaxial growth of a nanoscale, vertically faceted, one-dimensional, high-aspect ratio grating in III-V materials for integrated photonics

    E-print Network

    New Mexico, University of

    Epitaxial growth of a nanoscale, vertically faceted, one-dimensional, high-aspect ratio grating-dimensional 1D grating with vertical facets is reported. For a pattern direction along 110 , the kinetics of faceting in selective molecular-beam epitaxy MBE induce 11¯0 -type facets vertical to a GaAs 001 substrate

  9. Risk Management Institute Joint Seminar Joint Seminar -

    E-print Network

    Chaudhuri, Sanjay

    around their use of leverage. Research on optimal leverage in the money management industry, howeverRisk Management Institute Joint Seminar Joint Seminar - Risk Management Institute And Department A (S14, #03-10) Speaker Prof. Wang Hefei University of Illinois, Chicago Title Leverage Management

  10. Large-Scale Synthesis of Palladium Concave Nanocubes with High-Index Facets for Sustainable Enhanced Catalytic Performance

    PubMed Central

    Xie, Xiaobin; Gao, Guanhui; Pan, Zhengyin; Wang, Tingjun; Meng, Xiaoqing; Cai, Lintao

    2015-01-01

    The catalytic activity of palladium (Pd) nanostructures highly relies on their size and morphology, especially enclosed with high-index facets, which provide more active sites so as to enhance their catalytic performance comparing with their low-index facet counterparts. Herein, Pd concave nanocubes enclosed with {730} facets by a one-pot scalable liquid method, with various high-index facets are synthesized via tuning reduction kinetics. Due to their high-index facets, the Pd concave nanocubes exhibit much higher electrocatalytic activity and stability for methanol oxidation than the Pd nanocubes enclosed by {100} facets and commercial Pd/C. Furthermore, we scale up synthesis of Pd concave nanocubes by expanding the volume of all species to fifty times with high-yield production. PMID:25686863

  11. Large-Scale Synthesis of Palladium Concave Nanocubes with High-Index Facets for Sustainable Enhanced Catalytic Performance

    NASA Astrophysics Data System (ADS)

    Xie, Xiaobin; Gao, Guanhui; Pan, Zhengyin; Wang, Tingjun; Meng, Xiaoqing; Cai, Lintao

    2015-02-01

    The catalytic activity of palladium (Pd) nanostructures highly relies on their size and morphology, especially enclosed with high-index facets, which provide more active sites so as to enhance their catalytic performance comparing with their low-index facet counterparts. Herein, Pd concave nanocubes enclosed with {730} facets by a one-pot scalable liquid method, with various high-index facets are synthesized via tuning reduction kinetics. Due to their high-index facets, the Pd concave nanocubes exhibit much higher electrocatalytic activity and stability for methanol oxidation than the Pd nanocubes enclosed by {100} facets and commercial Pd/C. Furthermore, we scale up synthesis of Pd concave nanocubes by expanding the volume of all species to fifty times with high-yield production.

  12. Large-scale synthesis of palladium concave nanocubes with high-index facets for sustainable enhanced catalytic performance.

    PubMed

    Xie, Xiaobin; Gao, Guanhui; Pan, Zhengyin; Wang, Tingjun; Meng, Xiaoqing; Cai, Lintao

    2015-01-01

    The catalytic activity of palladium (Pd) nanostructures highly relies on their size and morphology, especially enclosed with high-index facets, which provide more active sites so as to enhance their catalytic performance comparing with their low-index facet counterparts. Herein, Pd concave nanocubes enclosed with {730} facets by a one-pot scalable liquid method, with various high-index facets are synthesized via tuning reduction kinetics. Due to their high-index facets, the Pd concave nanocubes exhibit much higher electrocatalytic activity and stability for methanol oxidation than the Pd nanocubes enclosed by {100} facets and commercial Pd/C. Furthermore, we scale up synthesis of Pd concave nanocubes by expanding the volume of all species to fifty times with high-yield production. PMID:25686863

  13. Defeaturing CAD models using a geometry-based size field and facet-based reduction operators.

    SciTech Connect

    Quadros, William Roshan; Owen, Steven James

    2010-04-01

    We propose a method to automatically defeature a CAD model by detecting irrelevant features using a geometry-based size field and a method to remove the irrelevant features via facet-based operations on a discrete representation. A discrete B-Rep model is first created by obtaining a faceted representation of the CAD entities. The candidate facet entities are then marked for reduction by using a geometry-based size field. This is accomplished by estimating local mesh sizes based on geometric criteria. If the field value at a facet entity goes below a user specified threshold value then it is identified as an irrelevant feature and is marked for reduction. The reduction of marked facet entities is primarily performed using an edge collapse operator. Care is taken to retain a valid geometry and topology of the discrete model throughout the procedure. The original model is not altered as the defeaturing is performed on a separate discrete model. Associativity between the entities of the discrete model and that of original CAD model is maintained in order to decode the attributes and boundary conditions applied on the original CAD entities onto the mesh via the entities of the discrete model. Example models are presented to illustrate the effectiveness of the proposed approach.

  14. Neurologically Intact Patient Following Bilateral Facet Dislocation: Case Report and Review of Literature

    PubMed Central

    Chakravarthy, Vikram; Mullin, Jeffrey P.; Abbott, E. Emily; Anderson, James; Benzel, Edward C.

    2014-01-01

    Background Complete spinal cord lesions and quadriplegia occur in 50%-84% of patients with bilateral facet dislocation. We present a patient who suffered both bilateral facet dislocation and bilateral pedicle fractures while remaining neurologically intact. Based on this case and our literature review, we hypothesize that bilateral facet dislocations without neurological deficits are accompanied by significant associated fractures that facilitate the maintenance of cervical spine canal patency. Case Report After a fall down a flight of stairs, an 86-year-old woman presented to the hospital complaining of neck pain. She denied numbness and weakness of her extremities. On physical examination she was neurologically intact without focal sensory or motor deficits and with normal reflexes throughout. Computed tomography (CT) of her neck demonstrated bilateral C5-C6 facet dislocation with locking of the C6 superior articular process dorsal to the C5 inferior articular process, as well as corresponding bilateral C6 pedicle fractures. Additional acute fractures were identified on the thoracic CT. Magnetic resonance imaging demonstrated no spinal cord compression, edema, or hemorrhage. The patient had a C6-C7 anterior cervical discectomy and allograft fusion and a C5-T1 anterior cervical plate with screw fixation. Conclusion Because bilateral facet dislocations without neurological deficits are rare, the most appropriate surgical intervention is not evident. We believe the best choice as a first step is an anterior cervical discectomy and allograft fusion with plating. PMID:24688342

  15. Progress report for FACETS (Framework Application for Core-Edge Transport Simulations)

    SciTech Connect

    Epperly, T W

    2009-04-20

    This role of this computer science SAP is to facilitate FACETS design and development by contributing CCA component technology and new application-specific technology. From a software perspective, the FACETS project is a very complex project. It is a combination of legacy software written in Fortran, Python, and C++ by various coding groups along with new software modules being written from scratch. The FACETS team is spread among 11 organizations and is geographically distributed from coast to coast. The fusion physics modules to be incorporated vary in terms of the model dimensions, typical time scale, and type of interactions with other components. Because FACETS is a complex project, it requires a component-based framework to facilitate the definition and composition of scientific applications from a suite of available fusion physics components. Component architectures have proven themselves in the business world and more recently in the scientific computing world. The CS SAP contributes fundamental tools like Babel to the FACETS framework and helps develop application-specific interfaces appropriate for the fusion physics modules.

  16. Facet-Dependent Electrical Conductivity Properties of Cu2O Crystals.

    PubMed

    Tan, Chih-Shan; Hsu, Shih-Chen; Ke, Wei-Hong; Chen, Lih-Juann; Huang, Michael H

    2015-03-11

    It is interesting to examine facet-dependent electrical properties of single Cu2O crystals, because such study greatly advances our understanding of various facet effects exhibited by semiconductors. We show a Cu2O octahedron is highly conductive, a cube is moderately conductive, and a rhombic dodecahedron is nonconductive. The conductivity differences are ascribed to the presence of a thin surface layer having different degrees of band bending. When electrical connection was made on two different facets of a rhombicuboctahedron, a diode-like response was obtained, demonstrating the potential of using single polyhedral nanocrystals as functional electronic components. Density of state (DOS) plots for three layers of Cu2O (111), (100), and (110) planes show respective metallic, semimetal, and semiconducting band structures. By examining DOS plots for varying number of planes, the surface layer thicknesses responsible for the facet-dependent electrical properties of Cu2O crystals have been determined to be below 1.5 nm for these facets. PMID:25706855

  17. A realistic kinetic Monte Carlo simulation of the faceting of a Pt(110) surface under reaction conditions.

    PubMed

    Monine, M I; Pismen, L M; Imbihl, R

    2004-12-01

    The faceting process on Pt(110) is studied with the help of a kinetic Monte Carlo model taking into account realistic Pt-Pt, Pt-CO, and Pt-O interactions. The activation energies of the allowed atomic steps are estimated using available computational and experimental data. The model well reproduces the region in the parameter space where faceting occurs. Under kinetic instability conditions, the simulated faceted pattern forms a periodic hill and valley structure with a lateral periodicity of approximately 140-170 A, which is comparable with experimental data. The simulations reproduce the development of faceting on a realistic time scale. PMID:15634090

  18. Do as You’re Told! Facets of Agreeableness and Early Adult Outcomes for Inner-City Boys

    PubMed Central

    Kern, Margaret L.; Duckworth, Angela L.; Urzúa, Sergio; Loeber, Rolf; Stouthamer-Loeber, Magda; Lynam, Donald R.

    2013-01-01

    With data from the middle cohort of the Pittsburgh Youth Study, a prospective longitudinal study of inner-city boys, we examined whether Big Five agreeableness facets could be reliably recovered in this sample, and whether facets predicted educational, occupational, social, and antisocial life outcomes assessed a decade later. Caregivers described their adolescent boys’ personalities using the Common California Q-Set; twelve years later, participants were interviewed and court records were obtained. Factor analyses recovered two facets: compliance and compassion. Compliance predicted more schooling and lower risk of unemployment, teenage fatherhood, and crime; compassion related to longer committed relationships. Findings highlight the value of studying personality at the facet level. PMID:24311824

  19. Systematic review of tests to identify the disc, SIJ or facet joint as the source of low back pain

    Microsoft Academic Search

    M. J. Hancock; C. G. Maher; J. Latimer; M. F. Spindler; J. H. McAuley; M. Laslett; N. Bogduk

    2007-01-01

    Clinical practice guidelines state that the tissue source of low back pain cannot be specified in the majority of patients.\\u000a However, there has been no systematic review of the accuracy of diagnostic tests used to identify the source of low back pain.\\u000a The aim of this systematic review was therefore to determine the diagnostic accuracy of tests available to clinicians

  20. Faceting and coarsening dynamics in the complex Swift-Hohenberg equation.

    PubMed

    Gelens, Lendert; Knobloch, Edgar

    2009-10-01

    The complex Swift-Hohenberg equation models pattern formation arising from an oscillatory instability with a finite wave number at onset and finds applications in lasers, optical parametric oscillators, and photorefractive oscillators. We show that with real coefficients this equation exhibits two classes of localized states: localized in amplitude only or localized in both amplitude and phase. The latter are associated with phase-winding states in which the real and imaginary parts of the order parameter oscillate periodically but with a constant phase difference between them. The localized states take the form of defects connecting phase-winding states with equal and opposite phase lag, and can be stable over a wide range of parameters. The formation of these defects leads to faceting of states with initially spatially uniform phase. Depending on parameters these facets may either coarsen indefinitely, as described by a Cahn-Hilliard equation, or the coarsening ceases leading to a frozen faceted structure. PMID:19905429

  1. Effect of antireflection facet coatings on the characteristics of a high-power red laser diode

    NASA Astrophysics Data System (ADS)

    Kim, Chang Zoo; Choi, Je Hyuk; Shin, Chan Soo; Kim, Hogyoung

    2014-05-01

    We investigated the effect of antireflection (AR) coatings on the performance of high-power red laser diodes (LDs). The AR coating at the front facet and the high reflection (HR) coating at the rear facet were deposited on cleaved facets. As an AR coating, SiO2 or Si3N4 single layers with different thicknesses were employed. When the reflectivity of the AR coating was 25%, the best LD performance was obtained. The fitting to the threshold current density vs. effective optical length plot produced a transparent current density of 310 A/cm2. Under continuous wave (cw) operation at 15 °C, the operating current was 1.41 A, and the operating voltage was 2.33 V with an optical output of 280 mW. At an operating temperature of 0 °C, we observed the maximum output power of about 390 mW.

  2. Charge separation in facet-engineered chalcogenide photocatalyst: a selective photocorrosion approach.

    PubMed

    Li, Naixu; Liu, Maochang; Zhou, Zhaohui; Zhou, Jiancheng; Sun, Yueming; Guo, Liejin

    2014-08-21

    Finding active sites for photocatalytic reduction and oxidation allows the mechanistic understanding of a given reaction, ensuring the rational design and fabrication of an efficient photocatalyst. Herein, using well-shaped Cu2WS4 decahedra as model photocatalysts, we demonstrated that photoinduced oxidative etching could be considered as an indication of the photooxidation reaction sites of chalcogenide photocatalyst as it only occurred on {101} facets of Cu2WS4 during photocatalytic hydrogen production. The photocatalytic reduction reaction, in contrast, was confined on its {001} facets. Based on this finding, the photocatalytic activity of Cu2WS4 decahedra could be further tailored by controlling the ratio of {001}/{101} facets. Thus, this work provides a general route to the determination of reactive sites on shaped chalcogenide photocatalysts. PMID:24993804

  3. Shapes, Sizes, and Faceting of Nanoscale Metal Particles for Applications in Catalysis

    SciTech Connect

    Strand, M. B.; Leong, G. J.; Dinh, H. N.; Richards, R. M.

    2013-01-01

    In an effort to reduce the world's dependence on fossil fuels, proton exchange membrane fuel cells (PEMFC) are commonly considered as a prime candidate for alternative energy sources. The efficiency of fuel cells is limited by the oxygen reduction reaction (ORR) which is driven by platinum based catalysts. Numerous methods have been developed to synthesize particles which contain more active surfaces by tuning shapes, sizes and facets. Here, we will present a study of a well known wet chemical reduction method targeting specific morphologies and the resulting electrochemical activity. Studying the relationship between Pt facets at the bulk phase single crystal level versus the nanoscale correlates the effects of faceting on activities. Studying the formation of crystals during the course of the synthesis via transmission electron microscopy (TEM) and small angle x-ray scattering (SAXS) provides mechanistic insight on growth, while electrochemical studies correlate physical properties to performance.

  4. Mesoporous NiO crystals with dominantly exposed {110} reactive facets for ultrafast lithium storage

    PubMed Central

    Su, Dawei; Ford, Mike; Wang, Guoxiu

    2012-01-01

    Faceted crystals with exposed highly reactive planes have attracted intensive investigations for applications such as hydrogen production, enhanced catalytic activity, and electrochemical energy storage and conversion. Herein, we report the synthesis of mesoporous NiO crystals with dominantly exposed {110} reactive facets by the thermal conversion of hexagonal Ni(OH)2 nanoplatelets. When applied as anode materials in lithium-ion batteries, mesoporous NiO crystals exhibit a high reversible lithium storage capacity of 700?mAh g?1 at 1 C rate in 100?cycles and an excellent cyclability. In particular, the dominantly exposed {110} reactive facets and mesoporous nanostructure of NiO crystals lead to ultrafast lithium storage, which mimics the high power delivery of supercapacitors. PMID:23226591

  5. {116} faceted anatase single-crystalline nanosheet arrays: facile synthesis and enhanced electrochemical performances

    NASA Astrophysics Data System (ADS)

    Li, Feng; Li, Xiaoning; Peng, Ranran; Zhai, Xiaofang; Yang, Shangfeng; Fu, Zhengping; Lu, Yalin

    2014-10-01

    Single-crystalline anatase TiO2 nanosheet arrays were synthesized on a transparent conductive fluorine-doped tin oxide (FTO) substrate with a unique one-step alcohol-thermal process. The nanosheets were nearly vertically grown on the FTO substrate along their <11&cmb.macr;0> zone, and they were dominated by {116} facets. The as-fabricated {116} faceted single-crystalline anatase nanosheet arrays exhibit a much higher reduction capacity and a much better electrochemical reversibility than both {001} faceted anatase single-crystalline nanosheet arrays and P25 film. The results indicate a promising application potential for the new material in the photoelectrochemical field.Single-crystalline anatase TiO2 nanosheet arrays were synthesized on a transparent conductive fluorine-doped tin oxide (FTO) substrate with a unique one-step alcohol-thermal process. The nanosheets were nearly vertically grown on the FTO substrate along their <11&cmb.macr;0> zone, and they were dominated by {116} facets. The as-fabricated {116} faceted single-crystalline anatase nanosheet arrays exhibit a much higher reduction capacity and a much better electrochemical reversibility than both {001} faceted anatase single-crystalline nanosheet arrays and P25 film. The results indicate a promising application potential for the new material in the photoelectrochemical field. Electronic supplementary information (ESI) available: Photo of the large area STNA-116, FESEM images of STNA-001 and STNA-116 with a series of growth time, the enlarged XRD pattern, the simulated SAED pattern, the reflectance spectra, the cyclic voltammograms of P25 on the FTO substrate. See DOI: 10.1039/c4nr04248d

  6. Faceting of {sigma}3 and {sigma}9 grain boundaries in Cu-Bi alloys

    SciTech Connect

    Straumal, B.B. [Laboratory of Interfaces in Metals, Institute of Solid State Physics, Institutskii prospect 15, 142432 Chernogolovka, Moscow District (Russian Federation)]. E-mail: straumal@issp.ac.ru; Polyakov, S.A. [Laboratory of Interfaces in Metals, Institute of Solid State Physics, Institutskii prospect 15, 142432 Chernogolovka, Moscow District (Russian Federation); Max-Planck-Institut fuer Metallforschung and Institut fuer Metallkunde, Heisenbergstr. 3, 70569 Stuttgart (Germany); Bischoff, E. [Max-Planck-Institut fuer Metallforschung and Institut fuer Metallkunde, Heisenbergstr. 3, 70569 Stuttgart (Germany); Gust, W. [Max-Planck-Institut fuer Metallforschung and Institut fuer Metallkunde, Heisenbergstr. 3, 70569 Stuttgart (Germany); Baretzky, B. [Max-Planck-Institut fuer Metallforschung and Institut fuer Metallkunde, Heisenbergstr. 3, 70569 Stuttgart (Germany)

    2005-01-10

    The faceting of {sigma}3 and {sigma}9 tilt grain boundaries (GBs) has been studied in bicrystals of pure Cu and Cu-Bi alloys containing 2.5 x 10{sup -3}, 10 x 10{sup -3} and 16 x 10{sup -3} at.% Bi. The {sigma}3(1 0 0), {sigma}9(1 0 0), {sigma}9(-1 1 0), and {sigma}9(-1 2 0) facets and non-CSL {sigma}3 82 deg 9R facet were observed, where {sigma} is the inverse density of coincidence sites. The ratio between GB energy, {sigma}{sub GB}, and surface energy, {sigma}{sub sur}, was measured by atomic force microscopy using the GB thermal-groove method. The GB energy and thermal-groove deepening rate increased slightly between 0 and 10 x 10{sup -3} at.% Bi for all facets studied. However, between 10 x 10{sup -3} and 16 x 10{sup -3} at.% Bi the GB energy increased dramatically [from a factor 2 for the {sigma}9(1 1 0) facet to 15 times larger for the {sigma}3(1 0 0) facet]. The thermal-groove deepening rate also increased by a factor of 10 in this concentration range. This change corresponds well with the GB solidus line (i.e., the formation of a stable layer of a liquid-like GB phase called GB prewetting) observed previously. Wulff diagrams were constructed using measured {sigma}{sub GB}/{sigma}{sub sur} values.

  7. Temporomandibular joint dislocation.

    PubMed

    Liddell, Aaron; Perez, Daniel E

    2015-02-01

    Dislocation of the temporomandibular joint is one of many pathophysiologic joint conditions that the oral and maxillofacial surgeon is challenged with managing. Managing a dislocated joint will inevitably be the challenge of most surgeons or physicians, whether in private or academic practice. Accordingly, this article addresses the pathophysiology associated with dislocation, in addition to treatment strategies aimed at managing acute, chronic, and recurrent dislocation. PMID:25483448

  8. The different facets of ice have different hydrophilicities: Friction at water / ice-I$_\\mathrm{h}$ interfaces

    E-print Network

    Louden, Patrick B

    2015-01-01

    We present evidence that the prismatic and secondary prism facets of ice-I$_\\mathrm{h}$ crystals possess structural features that can reduce the effective hydrophilicity of the ice/water interface. The spreading dynamics of liquid water droplets on ice facets exhibits long-time behavior that differs for the prismatic $\\{10\\bar{1}0\\}$ and secondary prism $\\{11\\bar{2}0\\}$ facets when compared with the basal $\\{0001\\}$ and pyramidal $\\{20\\bar{2}1\\}$ facets. We also present the results of simulations of solid-liquid friction of the same four crystal facets being drawn through liquid water, and find that the two prismatic facets exhibit roughly half the solid-liquid friction of the basal and pyramidal facets. These simulations provide evidence that the two prismatic faces have a significantly smaller effective surface area in contact with the liquid water. The ice / water interfacial widths for all four crystal facets are similar (using both structural and dynamic measures), and were found to be independent of the...

  9. Prediction of Job Satisfaction Based on Workplace Facets for Adjunct Business Faculty at Four-Year Universities

    ERIC Educational Resources Information Center

    Lewis, Vance Johnson

    2012-01-01

    The purpose of this study was to examine the job satisfaction of adjuncts in the curriculum area of business at four-year universities and to determine the roles that individual job facets play in creating overall job satisfaction. To explore which job facets and demographics predict job satisfaction for the population, participants were asked to…

  10. Violence Risk Assessment and Facet 4 of the Psychopathy Checklist: Predicting Institutional and Community Aggression in Two Forensic Samples

    ERIC Educational Resources Information Center

    Walters, Glenn D.; Heilbrun, Kirk

    2010-01-01

    The Psychopathy Checklist and Psychopathy Checklist-Revised (PCL/PCL-R) were used to predict institutional aggression and community violence in two groups of forensic patients. Results showed that Facet 4 (Antisocial) of the PCL/PCL-R or one of its parcels consistently achieved incremental validity relative to the first three facets, whereas the…

  11. Raters and Single Prompt-to-Prompt Equating Using the FACETS Model in a Writing Performance Assessment.

    ERIC Educational Resources Information Center

    Du, Yi; And Others

    The FACETS equating model meets the complex requirements for equating writing performance assessment across both raters and prompts. This study is based on an equating of the 1996 writing performance assessment in the Minneapolis Public Schools (Minnesota). Raters and prompts were equated simultaneously using the FACETS model. About 3,000 fifth…

  12. Traumatic unilateral lumbosacral jumped facet without fracture in a child – presentation of a safe treatment strategy for a rare injury

    Microsoft Academic Search

    Oszkar Szentirmai; Joshua Seinfeld; Kathryn Beauchamp; Vikas Patel

    2008-01-01

    The vast majority of pediatric lumbosacral spondylolisthesis have developmental etiology. Of the very rare type of pediatric lumbosacral facet dislocations, there are only three reported cases of a pediatric unilateral jumped facet injury. All of these cases are associated with fracture dislocation of L5-S1. Hyperflexion with rotation is thought to provoke this uncommon type of spine injury. The authors report

  13. Field and Photofield Emission Spectroscopy of Silver and Sodium Adsorbed on (100) and (110) Facets of Tungsten

    Microsoft Academic Search

    Ammar Derraa

    1995-01-01

    Silver and sodium adatoms on W(100) and W(110) facets of microscopic size have been studied in field and photofield emission. New and interesting findings are reported concerning the growth and the electronic structure of silver and sodium overlayers on tungsten. On (100), silver adatoms form a homogeneous overlayer up to an exposure of 3 monolayers (ML), while the (110) facet

  14. Unique Relationships between Facets of Mindfulness and Eating Pathology among Female Smokers

    PubMed Central

    Adams, Claire E.; McVay, Megan Apperson; Kinsaul, Jessica; Benitez, Lindsay; Vinci, Christine; Stewart, Diana W.; Copeland, Amy L.

    2013-01-01

    Female smokers often have higher levels of eating disorder symptoms than non-smokers, and concerns about eating and weight might interfere with smoking cessation. Thus, it is critical to identify factors to promote healthier eating and body image in this population. Initial research suggests that specific aspects of trait mindfulness predict lower body dissatisfaction and eating disorder symptoms among non-smokers. However, these relationships are unknown among smokers. The current study examined associations between facets of trait mindfulness and eating disorder symptoms in 112 college female smokers (83% Caucasian; mean age 20 years, SD = 1.69). After controlling for relevant sociodemographic variables, Describing and Nonjudging facets of mindfulness predicted lower bulimic symptoms and body dissatisfaction (ps < .05), while Acting with Awareness predicted lower bulimic and anorexic symptoms, ps < .05. Observing predicted higher anorexic symptoms, p < .05. These results suggest that specific mindfulness facets are related to lower eating disorder symptoms among smokers, whereas other facets are not associated or have a positive relationship with these symptoms. Mindfulness-based interventions focusing on Describing, Nonjudging, and Acting with Awareness may help to reduce eating pathology among female smokers, which could potentially improve smoking cessation rates in this population. PMID:23121795

  15. Analysis of Rater Severity on Written Expression Exam Using Many Faceted Rasch Measurement

    ERIC Educational Resources Information Center

    Prieto, Gerardo; Nieto, Eloísa

    2014-01-01

    This paper describes how a Many Faceted Rasch Measurement (MFRM) approach can be applied to performance assessment focusing on rater analysis. The article provides an introduction to MFRM, a description of MFRM analysis procedures, and an example to illustrate how to examine the effects of various sources of variability on test takers'…

  16. Consistently Orienting Facets in Polygon Meshes by Minimizing the Dirichlet Energy of Generalized Winding Numbers

    E-print Network

    Plotkin, Joshua B.

    orienting facets in polygon meshes by minimizing the Dirichlet energy of generalized winding numbers. While based on the Dirichlet energy of the generalized winding number. Our motivation came from the fact Dirichlet energy of the corresponding generalized winding number. 2 Method 2.1 Patch extraction

  17. A new chemical etching technique for formation of cavity facets of (GaAl)As lasers

    Microsoft Academic Search

    M. Wada; K. Hamada; T. Shibutani; H. Shimizu; M. Kume; K. Itoh; G. Kano; I. Teramoto

    1985-01-01

    A new chemical etching technique which offers excellent cavity facets of Ga \\/SUB 1-x\\/ Al \\/SUB x\\/ As lasers is reported. This technique is based on our finding that the crystallographic anisotropy in the conventional etching process of Ga \\/SUB 1-x\\/ Al \\/SUB x\\/ As multilayers depends strongly on the AlAs mode fraction x in every layer. A suitable combination

  18. Controlled synthesis and facets-dependent photocatalysis of TiO2 nanocrystals

    NASA Astrophysics Data System (ADS)

    Roy, Nitish; Park, Yohan; Sohn, Youngku; Pradhan, Debabrata

    2015-04-01

    Titanium dioxide (TiO2) is a wide band gap semiconductor that has been extensively used in several environmental applications including degradation of organic hazardous chemicals, water splitting to generate hydrogen, dye sensitized solar cells, self cleaning agents, and pigments. Herein we demonstrate the synthesis of TiO2 nanocrystals (NCs) with the shapes of ellipsoids, rods, cuboids, and sheets with different exposed facets using a noncorrosive and nontoxic chemical (i.e. diethanolamine) as the shape controlling agent, unlike hydrofluoric acid commonly used. The TiO2 NCs of diverse shapes with different exposed facets were tested for photocatalytic hydroxyl radical (OH•) formation, which determines their photocatalytic behavior and the results were compared with the standard P-25 Degussa. The formation rate of OH• per specific surface area was found to be >6 fold higher for rod-shaped TiO2 NCs than that of commercial Degussa P25 catalyst. The highest photocatalytic activity of rod-shaped TiO2 NCs is ascribed to the unique chemical environment of {010} exposed facets which facilitates the electron/hole separation in presence of {101} facets.

  19. Validity of Social, Moral and Emotional Facets of Self-Description Questionnaire II

    ERIC Educational Resources Information Center

    Leung, Kim Chau; Marsh, Herbert W.; Yeung, Alexander Seeshing; Abduljabbar, Adel S.

    2015-01-01

    Studies adopting a construct validity approach can be categorized into within- and between-network studies. Few studies have applied between-network approach and tested the correlations of the social (same-sex relations, opposite-sex relations, parent relations), moral (honesty-trustworthiness), and emotional (emotional stability) facets of the…

  20. Optical characterization of the facets of a heliostat J. A. Avellaner

    E-print Network

    Paris-Sud XI, Université de

    the heliostat reflector panels (facets) of a central tower type solar power station from an optical point and concentrate the solar direct radiation onto a receiver, located on top of a tower, that transfers the radiant (1980) 169-173 FÃ?VRIER 1980, PAGE Classification Physics Abstracts 42.85 1. Introduction. - A solar

  1. Polymer waveguide end facet roughness and optical input/output coupling loss for OPCB applications

    NASA Astrophysics Data System (ADS)

    Baghsiahi, Hadi; Wang, Kai; Pitwon, Richard; Selviah, David R.

    2014-03-01

    Electro-optical printed circuit board technology (EOCB) based on integrated planar polymer optical waveguides has been the subject of research and development for many years to provide a cost viable, fully integrated system embedded optical interconnect solution, however a number of constraints of this technology have yet to be overcome. Optical coupling loss at the input and output of the waveguides is one of the major issues and waveguide end facet roughness is one of the main sources of the coupling loss which is investigated in this paper. The results of a comprehensive investigation of the end facet roughness of multimode polymer waveguides, fabricated on FR4 printed circuit boards, PCBs, and its effect of optical loss are presented theoretically and experimentally. The waveguide end facet roughness was measured using an atomic force microscope, AFM, when the waveguides were cut using a milling router with various numbers of cutting edges called flutes. The optimized cutting parameters are derived and the optical coupling loss, between the laser source and the waveguide, due to the different roughness magnitudes is measured by experiment for the first time. To improve the surface quality and decrease the waveguide optical loss, a new fabrication technique for reducing the end facet roughness after cutting is proposed and demonstrated. The insertion loss was reduced by 2.60 dB +/- 1.3 dB which is more than that achieved by other conventional methods such as index matching fluid.

  2. Age and Gender Differences in the Relation between Self-Concept Facets and Self-Esteem

    ERIC Educational Resources Information Center

    Arens, A. Katrin; Hasselhorn, Marcus

    2014-01-01

    This study tested whether the gender intensification hypothesis applies to relations between multiple domain-specific self-concept facets and self-esteem. This hypothesis predicts gender-stereotypic differences in these relations and assumes they intensify with age. Furthermore, knowledge about gender-related or age-related differences in…

  3. Exploring the Relationship between Workaholism Facets and Personality Traits: A Replication in American Workers

    ERIC Educational Resources Information Center

    Aziz, Shahnaz; Tronzo, Casie L.

    2011-01-01

    In this study, we further explored whether any of the dimensions in the five-factor model of personality (i.e., openness to experience, conscientiousness, extraversion, agreeableness, and neuroticism) were related to facets of workaholism (i.e., work involvement, work drive, and work enjoyment) in a sample of American workers in various…

  4. Strain dependent facet stabilization in selective-area heteroepitaxial growth of GaN nanostructures

    E-print Network

    Sharma, Pradeep

    Strain dependent facet stabilization in selective-area heteroepitaxial growth of GaN nanostructures of submicron GaN islands on GaN-sapphire, AlN-sapphire, and bare sapphire substrates. It is shown that strain due to the lattice mismatch between GaN and the underlying substrate has a significant influence

  5. Infinity as a Multi-Faceted Concept in History and in the Mathematics Classroom

    ERIC Educational Resources Information Center

    Arzarello, Ferdinando; Bussi, Maria G., Bartolini; Robutti, Ornella

    2004-01-01

    This paper presents the conceptualisation of infinity as a multi-faceted concept, discussing two examples. The first is from history and illustrates the work of Euler, when using infinity in an algebraic context. The second sketches an activity in a school context, namely students who approach the definite integral with symbolic-graphic…

  6. Analysis of Scatterometer Observations of Saharan Ergs Using A Simple Rough Facet Model

    E-print Network

    Long, David G.

    Analysis of Scatterometer Observations of Saharan Ergs Using A Simple Rough Facet Model Haroon to the NSCAT and ESCAT observations over areas of known dune types in the Sahara. This analysis gives a unique of and , to study the sand surface geomorphology. The (, ) measurements over ergs from the Ku-band NASA

  7. Technology shapes every facet of modern life. Familiarity with the characteristics,

    E-print Network

    Ge, Qiaode Jeff

    Technology shapes every facet of modern life. Familiarity with the characteristics, capabilities, and limitations of current and emerging technologies is indispen- sable to wise and effective decisions and address the problems that technology often presents. Technologi- cal developments are indeed re

  8. Immediate open anterior reduction and antero-posterior fixation\\/fusion for bilateral cervical locked facets

    Microsoft Academic Search

    2005-01-01

    Summary Background. Bilateral cervical locked facets is a severe traumatic lesion, most frequently resulting in tetraplegia. The common treatment strategy has been an attempt of awake, closed reduction, adding general anesthesia, muscle relaxation and manual traction in difficult cases. In cases of failed closed reduction, open reduction has most commonly been performed by a posterior approach. Patients in the current

  9. The multiple facets of c-aminobutyric acid dysfunction in epilepsy Yehezkel Ben-Aria

    E-print Network

    Cossart, Rosa

    REVIEW The multiple facets of c-aminobutyric acid dysfunction in epilepsy Yehezkel Ben inhibition to excitation in the developing brain and in epilepsies. This review deals with recent while inhibiting those of the mother. In epilepsies, recurrent seizures also lead to an accumulation

  10. Motivation as a Facet of School Readiness in a Head Start Sample

    ERIC Educational Resources Information Center

    Henrich, Christopher C.; Wheeler, Crista M.; Zigler, Edward F.

    2005-01-01

    The EZ-Yale Personality Motivation Questionnaire (EZPQ) was used to measure motivation as a facet of school readiness in a sample of 133 children during the spring of their final year of Head Start. Three motivational constructs assessed by the EZPQ, academic mastery motivation, negative reaction tendency, and outerdirectedness, were associated…

  11. Flamenco + Geo: extending a hierarchical faceted metadata search interface with geographic capabilities

    Microsoft Academic Search

    Patricia L. Frontiera

    2008-01-01

    This paper describes initial work on developing a geographic information retrieval system that provides both spatial and text-based functionality. The system is an extension to Flamenco, an open source browse and search interface framework based on hierarchical faceted metadata.

  12. Using Self-Report Assessment Methods to Explore Facets of Mindfulness

    Microsoft Academic Search

    Ruth A. Baer; Gregory T. Smith; Jaclyn Hopkins; Jennifer Krietemeyer; Leslie Toney

    2006-01-01

    The authors examine the facet structure of mindfulness using five recently developed mindfulness questionnaires. Two large samples of undergraduate students completed mindfulness questionnaires and measures of other constructs. Psychometric properties of the mindfulness questionnaires were examined, including internal consistency and convergent and discriminant relationships with other variables. Factor analyses of the combined pool of items from the mindfulness questionnaires suggested

  13. Diffraction and external reflection by dielectric faceted particles Lei Bi a,, Ping Yang b

    E-print Network

    Baum, Bryan A.

    Diffraction and external reflection by dielectric faceted particles Lei Bi a,Ã?, Ping Yang b February 2010 Keywords: Diffraction External reflection Scattering Hexagonal ice crystal a b s t r a c to diffraction, external reflection and outgoing refracted waves. This paper focuses on diffraction and external

  14. When You're Lost for Words: Faceted Search with Autocompletion

    Microsoft Academic Search

    Holger Bast; Ingmar Weber

    2006-01-01

    In this paper, we show how the autocompletion data struc- ture of (2) can be used to answer faceted-search queries e- ciently. Specically , we have built a fully-functional browser- based search engine that can index collections with arbi- trary category information and that, after each keystroke from the user, computes and displays the following infor- mation: (i) words or

  15. Patterns of Astragalar Fibular Facet Orientation in Extant and Fossil Primates and Their Evolutionary

    E-print Network

    Boyer, Doug M.

    Sciences Center T-8, Stony Brook, NY 11794-8081 KEY WORDS astragalus; talus; fibula; haplorhine of the astragalus (5talus) has been proposed as one of few osteological synapomorphies of strepsirrhine primates" lemuri- form and lorisiform primates). The slope of the fibular facet of the astragalus has received

  16. Perennial Dreams ognition is a complex, multi-faceted and multi-level phenomenon. Unraveling it,

    E-print Network

    Indiana University

    Prologue Perennial Dreams ognition is a complex, multi-faceted and multi-level phenomenon, and intellectual threads that can be best understood through the relationships among its components. AI is a dream -- a dream of the creation of things in the human image, a dream that reveals the human quest for immortality

  17. Facets of Fairness: Equal Share, Equal Chance and Uniform Mechanisms Holger H. Hoos 1

    E-print Network

    Hoos, Holger H.

    !1 Chapter ! Facets of Fairness: Equal Share, Equal Chance and Uniform Mechanisms ! Holger H. Hoos 1 I. Introduction Fairness is a notion of universal importance ­ whether we play, compete or trade with each other, we tend to strive for situations in which everyone feels treated fairly. Conversely, lack

  18. Analyzing Process Quality of Early Childhood Education with Many Facet Rash Measurement Model

    ERIC Educational Resources Information Center

    Basturk, Ramazan; Isikoglu, Nesrin

    2008-01-01

    Quality of early childhood education institutions specifically, dimensions of process quality should be evaluated. Purpose of this study is to analyze process quality of early childhood education by using many-facet Rasch measurement model (MFRM). In this study, data were collected from twelve early childhood education institutions by four…

  19. Interproximal wear facets and tooth associations in the Pa?alar hominoid sample

    Microsoft Academic Search

    Insaf Gençturk; Berna Alpagut; Peter Andrews

    2008-01-01

    Interproximal wear facets were examined on hominoid teeth from the middle Miocene site at Pa?alar, Turkey. The aim was to find matches between adjacent premolar and molar teeth from single individuals that were collected in the field as isolated teeth and use them to reconstruct tooth rows. These were then used to investigate: (1) the wear gradient on the molar

  20. Berkeley Expressivity Questionnaire The Berkeley Expressivity Questionnaire assesses three facets of emotional expressivity: negative

    E-print Network

    Gross, James J.

    Berkeley Expressivity Questionnaire The Berkeley Expressivity Questionnaire assesses three facets-reports, peer ratings, and behavior. Journal of Personality and Social Psychology, 72, 435-448. Other references include: Gross, J.J. (2000). The Berkeley Expressivity Questionnaire. In J. Maltby, C.A. Lewis, & A

  1. Unique and Common Facets of Religion and Spirituality: Both Are Important

    Microsoft Academic Search

    Doug Oman

    2009-01-01

    This commentary describes a multidimensional approach that underlies much recent empirical research on religion and spirituality (RS) and health. Each faith tradition possesses its own particularities, and common facets shared with other traditions as a coherent resemblance. Taxonomies of RS dimensions vary from being coarse grained to fine grained. The most useful taxonomy depends upon the particular research question. Fine-grained

  2. An Examination of Blue- versus White-Collar Workers' Conceptualizations of Job Satisfaction Facets

    ERIC Educational Resources Information Center

    Hu, Xiaoxiao; Kaplan, Seth; Dalal, Reeshad S.

    2010-01-01

    This study examined the degree to which blue- versus white-collar workers differentially conceptualize various job facets, namely the work itself, co-workers, supervisors, and pay. To examine these potential differences, we conducted a series of analyses on job satisfaction ratings from two samples of university workers. Consistent with the study…

  3. Charge transfer, surface charging, and overlayer-induced faceting J. G. Che* and C. T. Chan

    E-print Network

    Che, Jingguang

    Charge transfer, surface charging, and overlayer-induced faceting J. G. Che* and C. T. Chan to analyze the change of surface energy of metallic surfaces upon surface charging. We then studied surface charging is main driving mechanism in view of such an empirical correlation. Our results show

  4. A Complete Description of Cones and Polytopes Including Hypervolumes of All Facets of a Polytope

    ERIC Educational Resources Information Center

    Jubete, F.; Castillo, E.

    2007-01-01

    In this paper methods and algorithms for identifying the main elements (edges and facets of any dimension) of a cone and a polytope, and calculating the corresponding hypervolumes are presented. The cones and polytopes are supposed to be given as the non-negative linear combination and the convex hull generated by a, not necessarily minimal, set…

  5. Construct Validity of the Five Facet Mindfulness Questionnaire in Meditating and Nonmeditating Samples

    Microsoft Academic Search

    Ruth A. Baer; Gregory T. Smith; Emily Lykins; Daniel Button; Jennifer Krietemeyer; Shannon Sauer; Erin Walsh; Danielle Duggan; J. Mark G. Williams

    2008-01-01

    Previous research on assessment of mindfulness by self-report suggests that it may include five component skills: observing, describing, acting with awareness, nonjudging of inner experience, and nonreactivity to inner experience. These elements of mindfulness can be measured with the Five Facet Mindfulness Questionnaire (FFMQ). The authors investigated several aspects of the construct validity of the FFMQ in experienced meditators and

  6. Construct Validity of the Five Facet Mindfulness Questionnaire in Meditating and Nonmeditating Samples

    ERIC Educational Resources Information Center

    Baer, Ruth A.; Smith, Gregory T.; Lykins, Emily; Button, Daniel; Krietemeyer, Jennifer; Sauer, Shannon; Walsh, Erin; Duggan, Danielle; Williams, J. Mark G.

    2008-01-01

    Previous research on assessment of mindfulness by self-report suggests that it may include five component skills: observing, describing, acting with awareness, nonjudging of inner experience, and nonreactivity to inner experience. These elements of mindfulness can be measured with the Five Facet Mindfulness Questionnaire (FFMQ). The authors…

  7. High Stability of Faceted Nanotubes and Fullerenes of Multiphase Layered Phosphorus: A Computational Study

    E-print Network

    Tománek, David

    phosphorus is considered superior to graphite for LIB applications [16,17], a similar benefit couldHigh Stability of Faceted Nanotubes and Fullerenes of Multiphase Layered Phosphorus compound of these carbon allotropes, the stable black phosphorus allotrope is a layered compound that can

  8. Mind Your Words: Positive and Negative Items Create Method Effects on the Five Facet Mindfulness Questionnaire

    ERIC Educational Resources Information Center

    Van Dam, Nicholas T.; Hobkirk, Andrea L.; Danoff-Burg, Sharon; Earleywine, Mitch

    2012-01-01

    Mindfulness, a construct that entails moment-to-moment effort to be aware of present experiences and positive attitudinal features, has become integrated into the sciences. The Five Facet Mindfulness Questionnaire (FFMQ), one popular measure of mindfulness, exhibits different responses to positively and negatively worded items in nonmeditating…

  9. Towards an Understanding of Facets and Exemplars of Big Data Applications Geoffrey C.Fox1

    E-print Network

    Towards an Understanding of Facets and Exemplars of Big Data Applications Geoffrey C.Fox1 Big Data applications from a variety of research and commercial areas and suggest a set Big Data properties, and then to understand applications with those properties. There are many

  10. Beyond facets: Semantic roots and modifiers as elements of a conceptual morphology

    E-print Network

    Soergel, Dagobert

    = Liver & Imaging & X-rays Hepatograph = Liver & Camera & X-rays Hepatogram = Liver & Image & X-rays The facets are body part (liver), process (imaging), apparatus (camera in the broad sense of any imaging Fermentable Solution (process) Solution (result) Dissolved Solvent Soluble Solubility Solubilize Cancer

  11. Facet-Dependent Catalytic Activity of Platinum Nanocrystals for Triiodide Reduction in Dye-Sensitized Solar Cells

    PubMed Central

    Zhang, Bo; Wang, Dong; Hou, Yu; Yang, Shuang; Yang, Xiao Hua; Zhong, Ju Hua; Liu, Jian; Wang, Hai Feng; Hu, P.; Zhao, Hui Jun; Yang, Hua Gui

    2013-01-01

    Platinum (Pt) nanocrystals have demonstrated to be an effective catalyst in many heterogeneous catalytic processes. However, pioneer facets with highest activity have been reported differently for various reaction systems. Although Pt has been the most important counter electrode material for dye-sensitized solar cells (DSCs), suitable atomic arrangement on the exposed crystal facet of Pt for triiodide reduction is still inexplicable. Using density functional theory, we have investigated the catalytic reaction processes of triiodide reduction over {100}, {111} and {411} facets, indicating that the activity follows the order of Pt(111) > Pt(411) > Pt(100). Further, Pt nanocrystals mainly bounded by {100}, {111} and {411} facets were synthesized and used as counter electrode materials for DSCs. The highest photovoltaic conversion efficiency of Pt(111) in DSCs confirms the predictions of the theoretical study. These findings have deepened the understanding of the mechanism of triiodide reduction at Pt surfaces and further screened the best facet for DSCs successfully. PMID:23670438

  12. Precursor salt assisted syntheses of high-index faceted concave hexagon and nanorod-like polyoxometalates

    NASA Astrophysics Data System (ADS)

    Pal, Jaya; Ganguly, Mainak; Mondal, Chanchal; Negishi, Yuichi; Pal, Tarasankar

    2014-12-01

    This paper describes an effective method for a precursor salt assisted fabrication and reshaping of two different polyoxometalates [(NH4)2Cu(MoO4)2 (ACM) and Cu3(MoO4)2(OH)2 (CMOH)] into five distinctive shapes through straightforward and indirect routes. Explicit regulation of the structural arrangements of ACM and CMOH has been studied in detail with altered precursor salt concentration employing our laboratory developed modified hydrothermal (MHT) method. Morphologically different ACM 3D architectures are evolved with higher molybdate concentration, whereas 1D growth of CMOH is observed with increased copper concentration. Interesting morphological transformation of the products has been accomplished employing one precursor salt at a time without using any other foreign reagent. It has been proven that large ACMs become labile in the presence of incoming Cu(ii) and NH4+ ions of the precursor salts. A new strategy for the conversion of faceted ACMs (hexagonal plate, circular plate and hollow flower) to exclusive CMOH nanorods through a Cu(ii) assisted reaction has been adopted. According to thermodynamic consideration, the synthesis of rare concave nanostructures with high index facet is still challenging due to their higher reactivity. In this study, concave hexagonal ACM with high index facet {hkl} has been successfully prepared for the first time from hexagonal ACM through simple etching with ammonium heptamolybdate (AHM), which is another precursor salt. Hexagonal ACM corrugates to a concave hexagon because of the higher reactivity of the {001} crystal plane than that of the {010} plane. It has been shown that high index facet exposed concave hexagonal ACM serves as a better catalyst for the photodegradation of dye than the other microstructures enclosed by low index facets.This paper describes an effective method for a precursor salt assisted fabrication and reshaping of two different polyoxometalates [(NH4)2Cu(MoO4)2 (ACM) and Cu3(MoO4)2(OH)2 (CMOH)] into five distinctive shapes through straightforward and indirect routes. Explicit regulation of the structural arrangements of ACM and CMOH has been studied in detail with altered precursor salt concentration employing our laboratory developed modified hydrothermal (MHT) method. Morphologically different ACM 3D architectures are evolved with higher molybdate concentration, whereas 1D growth of CMOH is observed with increased copper concentration. Interesting morphological transformation of the products has been accomplished employing one precursor salt at a time without using any other foreign reagent. It has been proven that large ACMs become labile in the presence of incoming Cu(ii) and NH4+ ions of the precursor salts. A new strategy for the conversion of faceted ACMs (hexagonal plate, circular plate and hollow flower) to exclusive CMOH nanorods through a Cu(ii) assisted reaction has been adopted. According to thermodynamic consideration, the synthesis of rare concave nanostructures with high index facet is still challenging due to their higher reactivity. In this study, concave hexagonal ACM with high index facet {hkl} has been successfully prepared for the first time from hexagonal ACM through simple etching with ammonium heptamolybdate (AHM), which is another precursor salt. Hexagonal ACM corrugates to a concave hexagon because of the higher reactivity of the {001} crystal plane than that of the {010} plane. It has been shown that high index facet exposed concave hexagonal ACM serves as a better catalyst for the photodegradation of dye than the other microstructures enclosed by low index facets. Electronic supplementary information (ESI) available: Details about chemicals, analytical instruments, HRTEM, BET surface area, SAED patterns, EDX, area mapping analysis, recyclability test and a schematic representation for MHT method. XRD, TEM, FESEM images, HRTEM images, nitrogen adsorption-desorption isotherm, SAED patterns, EDX and area mapping analysis. See DOI: 10.1039/c4nr06309k

  13. A new device used in the restoration of kinematics after total facet arthroplasty

    PubMed Central

    Vermesan, D; Prejbeanu, R; Daliborca, C Vlad; Haragus, H; Magureanu, M; Marrelli, M; Promenzio, L; Caprio, M; Cagiano, R; Tatullo, M

    2014-01-01

    Facet degeneration can lead to spinal stenosis and instability, and often requires stabilization. Interbody fusion is commonly performed, but it can lead to adjacent-segment disease. Dynamic posterior stabilization was performed using a total facet arthroplasty system. The total facet arthroplasty system was originally intended to restore the natural motion of the posterior stabilizers, but follow-up studies are lacking due to limited clinical use. We studied the first 14 cases (long-term follow-up) treated with this new device in our clinic. All patients were diagnosed with lumbar stenosis due to hypertrophy of the articular facets on one to three levels (maximum). Disk space was of normal height. The design of this implant allows its use only at levels L3–L4 and L4–L5. We implanted nine patients at the L4–L5 level and four patients at level L3–L4. Postoperative follow-up of the patients was obtained for an average of 3.7 years. All patients reported persistent improvement of symptoms, visual analog scale score, and Oswestry Disability Index score. Functional scores and dynamic radiographic imaging demonstrated the functional efficacy of this new implant, which represents an alternative technique and a new approach to dynamic stabilization of the vertebral column after interventions for spine decompression. The total facet arthroplasty system represents a viable option for dynamic posterior stabilization after spinal decompression. For the observed follow-up, it preserved motion without significant complications or apparent intradisk or adjacent-disk degeneration. PMID:24926203

  14. Campylobacter Prosthetic Joint Infection

    PubMed Central

    Vasoo, Shawn; Schwab, Jeramy J.; Cunningham, Scott A.; Robinson, Trisha J.; Cass, Joseph R.; Berbari, Elie F.; Walker, Randall C.; Osmon, Douglas R.

    2014-01-01

    A 75-year-old man was diagnosed with probable Campylobacter jejuni prosthetic knee infection after a diarrheal illness. Joint aspirate and operative cultures were negative, but PCR of prosthesis sonicate fluid was positive, as was stool culture. Nineteen additional cases of Campylobacter prosthetic joint infection reported in the literature are reviewed. PMID:24523462

  15. Behavior of jointed pipelines

    Microsoft Academic Search

    Singhal

    1984-01-01

    Experimental data on the axial, bending and torsional behavior of ductile cast iron pipes with rubber gasket joints is presented. Analytical expressions are provided which predict the resistance mechanisms and behavior of the joints. The bending mechanism is found to be quite different from the axial and torsional mechanism. By repeating the tests in a specially designed soil box, the

  16. Wedge Joints for Trusses

    NASA Technical Reports Server (NTRS)

    Wood, Kenneth E.

    1987-01-01

    Structure assembled rapidly with simple hand tools. Proposed locking wedge joints enable rapid assembly of lightweight beams, towers, scaffolds, and other truss-type structures. Lightweight structure assembled from tubular struts joined at nodes by wedge pins fitting into mating slots. Joint assembled rapidly by seating wedge pin in V-shaped slots and deforming end of strut until primary pawl engages it.

  17. Strategies for joint appointments.

    PubMed

    Royle, J; Crooks, D L

    1985-01-01

    The structure and policies governing joint appointments discussed above, are developed primarily through cooperation and collaboration between nursing service and education institutions. The joint appointee participates in the process of negotiation of salary, benefits and role responsibilities and exploration of the implications of the appointment for personal career development. Implementation and maintenance of the appointment requires the collaborative efforts of the joint appointee with both contracting agencies. Factors influencing the functioning of joint appointees have been identified and strategies to facilitate functioning presented. The joint appointee must be independent in thought and action yet adaptable to work within the boundaries of two social systems with differing values and expectations. Nursing management, peers and students can provide the support needed to overcome the frustrations and to achieve the rewards inherent in successful implementation of an exciting and innovative role. PMID:3852805

  18. Osteological and morphometric observations on intervertebral joints in the canine pre-diaphragmatic thoracic spine (Th1-Th9).

    PubMed

    Breit, S

    2002-11-01

    The incidence of facet aplasia was investigated in three groups of pure-bred dogs. We examined large breeds (Rough Collies, Doberman Pinschers, Rottweilers, Bernese Mountain Dogs, German Shepherd Dogs), chondrodystrophic breeds (Dachshunds, Pekinese dogs), and small breeds (Yorkshire Terriers, Maltese dogs). Uni- or bilateral aplasia of zygapophyseal (facet) joints was exclusively found in juvenile and adult small dogs, in which the incidence of aplasia ranged from between 26% (Th1) and 63% (Th8). There was no evidence that aplasia of zygapophyseal joints increases the risk of developing intervertebral disc disease or deformative spondylosis in small breeds. By applying the findings of previous empirical studies on intervertebral disc geometry and its biomechanical behaviour on the present morphometric results, there was an indication that the intervertebral disc may well compensate for the functional loss of aplastic zygapophyseal joints in small dogs. Biomechanical factors and their potential role as inducing agents of facet aplasia in the pre-diaphragmatic thoracic spine are also discussed. PMID:12505394

  19. Asymmetric effect of (000bar{1}) and (0001) facets on surface and interface properties of CdS single crystal

    NASA Astrophysics Data System (ADS)

    Singaevsky, A. F.; Piryatinski, Y. P.; Grynko, D. O.; Dimitriev, O. P.

    2011-07-01

    A different effect of (0001) and (000bar{1}) crystal facets of the cadmium sulfide (CdS) wurtzite structure terminated with Cd and S atoms, respectively, was observed in respect to the properties of the crystal surface and interface with metal or organic semiconductor contacts. In addition to the different surface morphology, a bare CdS single crystal showed different features in photoluminescence from the Cd- and S-terminated surfaces. Different adhesive behavior of poly(3,4-ethylenedioxythiophene): poly(styrene sulfonic acid) (PEDOT:PSS) films in respect to the Cd- and S-terminated facets of the crystal has also been found. Photovoltaic properties of hybrid CdS/PEDOT:PSS heterojunctions have been shown to be sensitive in respect to the crystal facet used. Thin films of aluminum (Al) equally deposited onto the opposite crystal facets revealed much smaller sheet resistance on the sulfur facet than on the cadmium one, which has been assigned to the difference in both chemical interaction with the surface atoms and surface morphology. Current-voltage characteristics of an apparently symmetric Al/CdS/Al structure with Al electrodes deposited onto the opposite crystal facets showed asymmetric behavior depending on the bias direction applied to the Cd or S-terminated facet, with the barrier for electrons at the Al/S-terminated interface, respectively.

  20. DRIFTS Evidence for Facet-Dependent Adsorption of Gaseous Toluene on TiO2 with Relative Photocatalytic Properties.

    PubMed

    Wang, Mengjiao; Zhang, Fan; Zhu, Xiaodi; Qi, Zeming; Hong, Bin; Ding, Jianjun; Bao, Jun; Sun, Song; Gao, Chen

    2015-02-10

    Effective adsorption is of great importance to the photocatalytic degradation of volatile organic compounds. Herein, we succeeded in the preparation of anatase TiO2 with clean dominant {001} and {101} facets. By using in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) equipped with a homemade reaction system and a coupling gas-dosing system, we found that TiO2 with dominant {001} facets exhibits higher toluene adsorption capacity than TiO2 with dominant {101} facets, which may be attributed to the different number of unsaturated 5c-Ti capable of forming the main active adsorption sites (terminal Ti-OH species). TiO2 with dominant {001} facets shows a significantly high photocatalytic degradation performance, with its degradation rate being 6 times higher than that of dominant {101} facets. Combined with simulation results, it is suggested that the synergetic effects of the formation of specific active adsorption sites, the low adsorption energy for toluene, and preservation of the free molecularly adsorbed water on the surface promote the degradation of gaseous toluene on the dominant {001} facets. This study exemplifies that the facet-dependent adsorption of volatile organic compounds is one of the most important factors to effectively engineer photocatalysts for air purification. PMID:25602129

  1. Development of big five domains and facets in adulthood: mean-level age trends and broadly versus narrowly acting mechanisms.

    PubMed

    Soto, Christopher J; John, Oliver P

    2012-08-01

    Data from a cross-sectional sample (N?=?601 men and women) and a longitudinal sample (N?=?125 women) were used to test hypotheses about the development of Big Five domains and facets from early adulthood through middle age. Analyses of mean-level age trends indicated that overall Agreeableness and Conscientiousness increased with age and that several facets showed distinctive trends that replicated across the samples. Cross-sectional analyses of trait intercorrelations and covariances indicated that interrelations between the Big Five domains, and between their more specific facets, were quite similar at older versus younger ages. Finally, longitudinal analyses of individual-level changes indicated that (a) different people's personalities changed in markedly different ways; (b) these changes were predominantly independent, rather than correlated, across Big Five domains; and (c) the pattern of change correlations between Big Five facets could be explained by the facets' interrelations at the first assessment time. Taken together, these results suggest that a complete understanding of personality development requires consideration of facet-level traits and that adult personality development is predominantly influenced by narrowly acting mechanisms that each affect a single Big Five domain, or a small cluster of related facets, rather than by broadly acting mechanisms that simultaneously affect previously independent traits. PMID:22091969

  2. Multi-wavelength light emission from three-dimensional AlGaN quantum wells fabricated on facet structures

    NASA Astrophysics Data System (ADS)

    Kataoka, Ken; Yamaguchi, Masanori; Fukushima, Kensuke; Funato, Mitsuru; Kawakami, Yoichi

    2014-03-01

    Faceted three-dimensional (3D) AlGaN/AlN multiple quantum wells (MQWs) with semipolar {1?101} and polar (0001) planes are fabricated by a regrowth technique based on metalorganic vapor phase epitaxy (MOVPE) on trench-patterned AlN templates. Similar 3D microfacet structures with different height are formed on top of and at the bottom of the AlN trench. Cathodoluminescence (CL) spectra are separately acquired at semipolar and (0001) facet QWs at room temperature (RT). The peak energies of {1?101} facet QWs and (0001) facet QWs on higher 3D structures are 5.42 and 5.43 eV, respectively, while that of (0001) facet QWs on lower 3D structures is 5.23eV. Through structural analyses using transmission electron microscopy (TEM), the peak energy difference between the {1?101} QWs and the lower (0001) QWs is ascribed mainly to suppressed internal electric fields in the {1?101} facet QWs. Furthermore, Al spatial distribution causes the peak energy difference between the (0001) facet QWs.

  3. Highly reactive {001} facets of TiO2-based composites: synthesis, formation mechanism and characterization

    NASA Astrophysics Data System (ADS)

    Ong, Wee-Jun; Tan, Lling-Lling; Chai, Siang-Piao; Yong, Siek-Ting; Mohamed, Abdul Rahman

    2014-01-01

    Titanium dioxide (TiO2) is one of the most widely investigated metal oxides due to its extraordinary surface, electronic and catalytic properties. However, the large band gap of TiO2 and massive recombination of photogenerated electron-hole pairs limit its photocatalytic and photovoltaic efficiency. Therefore, increasing research attention is now being directed towards engineering the surface structure of TiO2 at the most fundamental and atomic level namely morphological control of {001} facets in the range of microscale and nanoscale to fine-tune its physicochemical properties, which could ultimately lead to the optimization of its selectivity and reactivity. The synthesis of {001}-faceted TiO2 is currently one of the most active interdisciplinary research areas and demonstrations of catalytic enhancement are abundant. Modifications such as metal and non-metal doping have also been extensively studied to extend its band gap to the visible light region. This steady progress has demonstrated that TiO2-based composites with {001} facets are playing and will continue to play an indispensable role in the environmental remediation and in the search for clean and renewable energy technologies. This review encompasses the state-of-the-art research activities and latest advancements in the design of highly reactive {001} facet-dominated TiO2via various strategies, including hydrothermal/solvothermal, high temperature gas phase reactions and non-hydrolytic alcoholysis methods. The stabilization of {001} facets using fluorine-containing species and fluorine-free capping agents is also critically discussed in this review. To overcome the large band gap of TiO2 and rapid recombination of photogenerated charge carriers, modifications are carried out to manipulate its electronic band structure, including transition metal doping, noble metal doping, non-metal doping and incorporating graphene as a two-dimensional (2D) catalyst support. The advancements made in these aspects are thoroughly examined, with additional insights related to the charge transfer events for each strategy of the modified-TiO2 composites. Finally, we offer a summary and some invigorating perspectives on the major challenges and new research directions for future exploitation in this emerging frontier, which we hope will advance us to rationally harness the outstanding structural and electronic properties of {001} facets for various environmental and energy-related applications.

  4. Highly reactive {001} facets of TiO2-based composites: synthesis, formation mechanism and characterization.

    PubMed

    Ong, Wee-Jun; Tan, Lling-Lling; Chai, Siang-Piao; Yong, Siek-Ting; Mohamed, Abdul Rahman

    2014-02-21

    Titanium dioxide (TiO2) is one of the most widely investigated metal oxides due to its extraordinary surface, electronic and catalytic properties. However, the large band gap of TiO2 and massive recombination of photogenerated electron-hole pairs limit its photocatalytic and photovoltaic efficiency. Therefore, increasing research attention is now being directed towards engineering the surface structure of TiO2 at the most fundamental and atomic level namely morphological control of {001} facets in the range of microscale and nanoscale to fine-tune its physicochemical properties, which could ultimately lead to the optimization of its selectivity and reactivity. The synthesis of {001}-faceted TiO2 is currently one of the most active interdisciplinary research areas and demonstrations of catalytic enhancement are abundant. Modifications such as metal and non-metal doping have also been extensively studied to extend its band gap to the visible light region. This steady progress has demonstrated that TiO2-based composites with {001} facets are playing and will continue to play an indispensable role in the environmental remediation and in the search for clean and renewable energy technologies. This review encompasses the state-of-the-art research activities and latest advancements in the design of highly reactive {001} facet-dominated TiO2via various strategies, including hydrothermal/solvothermal, high temperature gas phase reactions and non-hydrolytic alcoholysis methods. The stabilization of {001} facets using fluorine-containing species and fluorine-free capping agents is also critically discussed in this review. To overcome the large band gap of TiO2 and rapid recombination of photogenerated charge carriers, modifications are carried out to manipulate its electronic band structure, including transition metal doping, noble metal doping, non-metal doping and incorporating graphene as a two-dimensional (2D) catalyst support. The advancements made in these aspects are thoroughly examined, with additional insights related to the charge transfer events for each strategy of the modified-TiO2 composites. Finally, we offer a summary and some invigorating perspectives on the major challenges and new research directions for future exploitation in this emerging frontier, which we hope will advance us to rationally harness the outstanding structural and electronic properties of {001} facets for various environmental and energy-related applications. PMID:24384624

  5. Compliant Joints For Robots

    NASA Technical Reports Server (NTRS)

    Kerley, James J., Jr.

    1990-01-01

    Compliant joints devised to accommodate misalignments of tools and/or workpieces with respect to robotic manipulators. Has characteristics and appearance of both universal-joint and cable-spring-type flexible shaft coupling. Compliance derived from elastic properties of short pieces of cable. Compliance of joint determined by lengths, distances between, relative orientations, thickness of strands, number of strands, material, amount of pretwist, and number of short pieces of cable. Worm-drive mechanism used to adjust lengths to vary compliance as needed during operation.

  6. Facets of impulsivity in the relationship between antisocial personality and abstinence.

    PubMed

    Sargeant, Marsha N; Bornovalova, Marina A; Trotman, Adria J-M; Fishman, Shira; Lejuez, Carl W

    2012-03-01

    Most individuals who enter drug treatment programs are unable to maintain long-term abstinence. This problem is especially relevant for those presenting with Antisocial Personality Disorder (ASPD). In examining potential mechanisms underlying the relationship between ASPD and abstinence, one factor that may be especially useful is the personality variable of impulsivity. Thus, the current study examined ASPD status in relation to longest abstinence attempt among 117 substance use treatment-seeking individuals, considering the mediating role of five facets of impulsivity: urgency, perseverance, premeditation, control, and delay discounting. Results indicated that individuals with ASPD evidenced shorter previous abstinence attempts and lower levels of perseverance and control than those without ASPD. Further, lower levels of control were associated with shorter abstinence attempts. Finally, control mediated the relationship between ASPD and longest quit attempt. These results suggest the potential value of multiple facets of impulsivity in efforts to understand relapse and subsequent treatment development efforts. PMID:22153489

  7. The associations between two facets of narcissism and eating disorder symptoms.

    PubMed

    Gordon, Kathryn H; Dombeck, Joseph J

    2010-12-01

    The current study sought to examine the relationships between two facets of narcissism (vulnerable and grandiose) and eating disorder symptoms. Based upon previous research (Davis, Claridge, & Cerullo, 1997), it was predicted that the vulnerable narcissism facet would be more strongly associated with eating disorder symptoms because of the tendency for vulnerable narcissists to base their self-worth on their appearance (Zeigler-Hill, Clark, & Picard, 2008). The hypotheses were tested cross-sectionally in a sample of 355 male and female undergraduate students. Results generally conformed to prediction, in that vulnerable narcissism tended to be positively correlated with eating disorder symptoms, and this relationship was partially mediated by self-worth that is contingent upon physical appearance. Our findings are consistent with the notion that vulnerable narcissism is a risk factor for eating disorder symptoms because it is associated with a drive to improve self-worth through the enhancement of physical appearance. PMID:20850065

  8. It's in the mix: psychological distress differs between combinations of alexithymic facets

    PubMed Central

    Alkan Härtwig, Elif; Crayen, Claudia; Heuser, Isabella; Eid, Michael

    2014-01-01

    Alexithymia is a personality trait characterized by difficulties in identifying, describing, and communicating one's emotions. The aim of the present study is to examine the usefulness of a typological approach considering the interaction between distinct alexithymic features within a population of high-alexithymic German adults (N = 217). Latent profile analysis (LPA) was employed to test for possible underlying profiles. A 3-profile solution showed the best fit: The profiles can be described as (1) “low”: lower load on all facets of alexithymia, (2) “mixed”: specific problems on identifying emotions, and (3) “high”: higher load on all facets of alexithymia. Moreover, this study tested how these profiles differed in psychological distress. “Mixed” profile, with specific problems on identifying emotions showed the highest levels of psychological distress. The present study suggests the importance of a specific combination of alexithymic features, rather than total alexithymia scores, as a risk factor for psychological distress. PMID:25429275

  9. Reconstructing cultural behavior from dental wear studies: Is para-facets analysis approach scientifically valid?

    PubMed

    Sarig, Rachel; Tillier, Anne-marie

    2014-06-01

    It is common knowledge, that in archaic populations teeth were used as tools, this behavior can be studied by evaluating attrition patterns. Parafacets were defined as nonmasticatory wear areas that have no antagonist matching wear facets. The presence of the parafacets led to far-reaching conclusions regarding cultural interactions between Near Eastern Neanderthals and anatomically modern humans. This study was aimed to examine the identification of parafacets in some of the Qafzeh specimens. Based on findings of our research we suggest that the attrition facets mistakenly considered as parafacets are in fact the result of the static and dynamic occlusion. Therefore the observations induce much less dramatic interpretation. We here propose several guidelines that would be beneficial in that they aim to evaluate the parafacets with heightened accuracy. PMID:24767822

  10. Culture - joint fluid

    MedlinePLUS

    Joint fluid culture ... fungi, or viruses grow. This is called a culture. If such microorganisms are detected, other tests may ... is no special preparation needed for the lab culture. For information on preparing for the removal of ...

  11. Healthy Joints Matter

    MedlinePLUS

    ... caused by a buildup of uric acid (YOOR-ic acid) crystals in the joints, most commonly in ... form of arthritis called psoriatic (sore-ee-AT-ic) arthritis. Rheumatoid arthritis (ROO-muh-toid ar-THRY- ...

  12. (113) Facets of Si-Ge/Si Islands; Atomic Scale Simulation

    NASA Astrophysics Data System (ADS)

    Kassem, Hassan

    We have studied, by computer simulation, some static and vibrationnal proprieties of SiGe/Si islands. We have used a Valence Force Field combined to Monte Carlo technique to study the growth of Ge and SiGe on (001)Si substrates. We have focalised on the case of large pyramidal islands presenting (113) facets on the free (001)Si surface with various non uniform composition inside the islands. The deformation inside the islands and Raman spectroscopy are discussed.

  13. Cognitive and emotional facets of test anxiety in African American school children

    Microsoft Academic Search

    Rona Carter; Sandra Williams; Wendy K. Silverman

    2008-01-01

    This study used confirmatory factor analysis (CFA) to investigate whether test anxiety (TA) can be conceptualised as a bidimensional construct consisting of cognitive and emotional facets in 152 African American school children, ages 8 to 13 years, M=9.98 years (SD=1.13 years); 54% girls. A two-factor model was determined a priori by classifying items from the Test Anxiety Scale for Children

  14. First results from core-edge parallel composition in the FACETS project.

    SciTech Connect

    Cary, J. R.; Candy, J.; Cohen, R. H.; Krasheninnikov, S.; McCune, D. C.; Estep, D. J.; Larson, J.; Malony, A. D.; Pankin, A.; Worley, P. H.; Carlsson, J. A.; Hakim, A. H.; Hamill, P.; Kruger, S.; Miah, M.; Muzsala, S.; Pletzer, A.; Shasharina, S.; Wade-Stein, D.; Wang, N.; Balay, S.; McInnes, L.; Zhang, H.; Casper, T.; Diachin, L. (Mathematics and Computer Science); (Tech-X Corp.); (General Atomics); (LLNL); (Univ. of California at San Diego); (Princeton Plasma Physics Lab.); (Colorado State Univ.); (ParaTools Inc.); (Lehigh Univ.); (ORNL)

    2008-01-01

    FACETS (Framework Application for Core-Edge Transport Simulations), now in its second year, has achieved its first coupled core-edge transport simulations. In the process, a number of accompanying accomplishments were achieved. These include a new parallel core component, a new wall component, improvements in edge and source components, and the framework for coupling all of this together. These accomplishments were a result of an interdisciplinary collaboration among computational physics, computer scientists, and applied mathematicians on the team.

  15. First results from core-edge parallel composition in the FACETS project

    SciTech Connect

    Cary, John R. [Tech-X Corporation; Candy, Jeff [General Atomics; Cohen, Ronald H. [Lawrence Livermore National Laboratory (LLNL); Krasheninnikov, Sergei [University of California, San Diego; McCune, Douglas [Princeton Plasma Physics Laboratory (PPPL); Estep, Donald J [Colorado State University, Fort Collins; Larson, Jay [Argonne National Laboratory (ANL); Malony, Allen [University of Oregon; Pankin, A. [Lehigh University, Bethlehem, PA; Worley, Patrick H [ORNL; Carlsson, Johann [Tech-X Corporation; Hakim, A H [Tech-X Corporation; Hamill, P [Tech-X Corporation; Kruger, Scott [Tech-X Corporation; Miah, Mahmood [Tech-X Corporation; Muzsala, S [Tech-X Corporation; Pletzer, Alexander [Tech-X Corporation; Shasharina, Svetlana [Tech-X Corporation; Wade-Stein, D [Tech-X Corporation; Wang, N [Tech-X Corporation; Balay, Satish [Argonne National Laboratory (ANL); McInnes, Lois [Argonne National Laboratory (ANL); Zhang, Hong [Argonne National Laboratory (ANL); Casper, T. A. [Lawrence Livermore National Laboratory (LLNL); Diachin, Lori [Lawrence Livermore National Laboratory (LLNL); Epperly, Thomas [Lawrence Livermore National Laboratory (LLNL); Rognlien, T. D. [Lawrence Livermore National Laboratory (LLNL); Fahey, Mark R [ORNL; Cobb, John W [ORNL; Morris, A [University of Oregon; Shende, Sameer [University of Oregon; Hammett, Greg [Princeton Plasma Physics Laboratory (PPPL); Indireshkumar, K [Tech-X Corporation; Stotler, D. [Princeton Plasma Physics Laboratory (PPPL); Pigarov, A [University of California, San Diego

    2008-01-01

    FACETS (Framework Application for Core-Edge Transport Simulations), now in its second year, has achieved its first coupled core-edge transport simulations. In the process, a number of accompanying accomplishments were achieved. These include a new parallel core component, a new wall component, improvements in edge and source components, and the framework for coupling all of this together. These accomplishments were a result of an interdisciplinary collaboration among computational physics, computer scientists, and applied mathematicians on the team.

  16. Adatom Ascending at Step Edges and Faceting on fcc Metal (110) Surfaces

    SciTech Connect

    Zhu, W. [Chinese Academy of Sciences; de Mongeot, F. B. [INFM-Unita di Genova and Dipartimento di Fisica, Italy; Valbusa, U. [INFM-Trinta di Genova and Dipartimento di Fisica, Italy; Wang, E. G. [International Center for Quantum Structures and Institute of Physics, China; Zhang, Zhenyu [ORNL

    2004-01-01

    Using first-principles total-energy calculations, we show that an adatom can easily climb up at monatomic-layer-high steps on several representative fcc metal (110) surfaces via a place exchange mechanism. Inclusion of such novel adatom ascending processes in kinetic Monte Carlo simulations of Al(110) homoepitaxy as a prototypical model system can lead to the existence of an intriguing faceting instability, whose dynamical evolution and kinetic nature are explored in comparison with experimental observations.

  17. Evaluation of Temporal Diagnostic Techniques for Two-Bunch Facet Beam

    SciTech Connect

    Litos, M.D.; Bionta, M.R.; Dolgashev, V.A.; England, R.J.; Fritz, D.; Gilevich, S.; Hering, Ph.; Hogan, M.J.; /SLAC

    2011-08-19

    Three temporal diagnostic techniques are considered for use in the FACET facility at SLAC, which will incorporate a unique two-bunch beam for plasma wakefield acceleration experiments. The results of these experiments will depend strongly on the the inter-bunch spacing as well as the longitudinal profiles of the two bunches. A reliable, singleshot, high resolution measurement of the beam's temporal profile is necessary to fully quantify the physical mechanisms underlying the beam driven plasma wakefield acceleration. In this study we show that a transverse deflecting cavity is the diagnostic which best meets our criteria. Based on our laboratory testing, numerical calculations, and simulations of the three single-shot temporal diagnostic devices, the X-band TCAV system is the best candidate for resolving FACET's two-bunch beam, with an estimated resolution of 7 {micro}m. Both the S-band TCAV system and the EO system could resolve the peak-to-peak separation of the two bunches in the FACET beam with estimated resolutions of 25 {micro}m and 30 {micro}m, respectively, but would be unable to resolve the temporal profiles of the individual bunches themselves. Because the TCAV signal is more easily interpreted and because the reliability of the EO system is less well known, however, the S-band TCAV system would be the next preferred option after the X-band TCAV system. The Fesca-200 streak camera, though simple, compact, and reliable, is unable to achieve a resolution that would be of use to FACET.

  18. Mass transport, faceting and behavior of dislocations in GaN

    SciTech Connect

    Nitta, S.; Kashima, T.; Kariya, M.; Yukawa, Y.; Yamaguchi, S.; Amano, H.; Akasaki, I.

    2000-07-01

    The behavior of threading dislocations during mass transport of GaN was investigated in detail by transmission electron microscopy. Mass transport occurred at the surface. Therefore, growing species are supplied from the in-plane direction. The behavior of threading dislocations was found to be strongly affected by the mass transport process as well as the high crystallographic anisotropy of the surface energy of the facets particular to GaN.

  19. Abnormal grain growth and grain boundary faceting in a model Ni-base superalloy

    Microsoft Academic Search

    S. B Lee; D. Y Yoon; M. F Henry

    2000-01-01

    Normal or abnormal grain growth in a model Ni-base superalloy is observed to depend on the grain boundary structure when heat-treated in a solid solution temperature range above the solvus temperature (1150°C) of the ?? phase. When heat-treated at 1200°C abnormal grain growth occurs and most of the grain boundaries are observed to be faceted by optical microscopy, transmission electron

  20. Space-time adaptive processing with a half-cylinder faceted conformal antenna

    Microsoft Academic Search

    Svante Björklund

    2009-01-01

    Conformal antennas, which assumes the shape of the platform, have several advantages, like reduced weight and space; aerodynamic design and increased field of view.We are interested in detection of moving ground targets with air-borne radar with three antenna geometries: faceted or smooth vertical half-cylinder and plane forward-looking. We study important clutter properties for suppressing the clutter with STAP (Space-Time Adaptive

  1. Theoretical analysis and fabrication of antireflection coatings on laser-diode facets

    Microsoft Academic Search

    Tadashi Saitoh; Takaaki Mukai; Osamu Mikami

    1985-01-01

    Reflectivity of an antireflection-(AR) coated laser-diode (LD) facet is analyzed on the basis of a slab waveguide model and an angular spectrum approach. The reflectivities of single- and double-layer AR coatings on 1.55-?m GaInAsP\\/InP LD's are numerically calculated. Optimum film parameters, such as thickness and refractive index of single-layer AR coating films, are obtained as functions of the active layer

  2. The dimensionality of self-esteem: II. Hierarchical facet model for revised measurement scales

    Microsoft Academic Search

    James S. Fleming; Barbara E. Courtney

    1984-01-01

    A hierarchical facet model of self-esteem proposed by R. J. Shavelson et al was partially tested in a previous study by J. S. Fleming and W. A. Watts . Their 3 factors, which were labeled Self-Regard, Social Confidence, and School Abilities, corresponded to 3 of the 4 dimensions posited by Shavelson et al. Predictions of other individual-difference variables from these

  3. Fractional vertices, cuts and facets of the simple plant location problem

    Microsoft Academic Search

    Monique Guignard

    This paper investigates the structure of the Integer Programming Polytope of an uncapacitated (simple) plant location problem.\\u000a One can describe families of fractional vertices and derive from them valid inequalities for the integer problem. Some of\\u000a these will actually be shown to be facets of the integer polytope. Also some families of SPLP with large duality gaps will\\u000a be described,

  4. Facet-dependent disorder in pristine high-voltage lithium-manganese-rich cathode material.

    PubMed

    Dixit, Hemant; Zhou, Wu; Idrobo, Juan-Carlos; Nanda, Jagjit; Cooper, Valentino R

    2014-12-23

    Defects and surface reconstructions are thought to be crucial for the long-term stability of high-voltage lithium-manganese-rich cathodes. Unfortunately, many of these defects arise only after electrochemical cycling which occurs under harsh conditions, making it difficult to fully comprehend the role they play in degrading material performance. Recently, it has been observed that defects are present even in the pristine material. This study, therefore, focuses on examining the nature of the disorder observed in pristine Li1.2Ni0.175Mn0.525Co0.1O2 (LNMCO) particles. Using atomic-resolution Z-contrast imaging and electron energy loss spectroscopy measurements, we show that there is indeed a significant amount of antisite defects present in this material, with transition metals substituting on Li metal sites. Furthermore, we find a strong segregation tendency of these types of defects toward open facets (surfaces perpendicular to the layered arrangement of atoms) rather than closed facets (surfaces parallel to the layered arrangement of atoms). First-principles calculations identify antisite defect pairs of Ni swapping with Li ions as the predominant defect in the material. Furthermore, energetically favorable swapping of Ni on the Mn sites was observed to lead to Mn depletion at open facets. Relatively, low Ni migration barriers also support the notion that Ni is the predominant cause of disorder. These insights suggest that certain facets of the LNMCO particles may be more useful for inhibiting surface reconstruction and improving the stability of these materials through careful consideration of the exposed surface. PMID:25415876

  5. Optimization of bonded joints

    NASA Technical Reports Server (NTRS)

    Ojalvo, I. U.

    1983-01-01

    A procedure for minimizing the elastic shear stress concentration in adhesive lap joints is presented. The proposed method is based upon tapering the adherends to achieve smooth stiffness transitions and uniform shear stresses. Both single and double lap splices are considered, but numerical examples are restricted to the case of double lap joints. Nonisotropic materials and nonoptimum design limitations, such as minimum and maximum thickness adherends, load-line eccentricity, and peel stresses are treated, and typical results are presented.

  6. Joint Contact Stress

    PubMed Central

    Brand, Richard A

    2005-01-01

    A joint's normal mechanical history contributes to the maintenance of articular cartilage and underlying bone. Loading facilitates the flow of nutrients into cartilage and waste products away, and additionally provides the mechanical signals essential for normal cell and tissue maintenance. Deleteriously low or high contact stresses have been presumed to result in joint deterioration, and particular aspects of the mechanical environment may facilitate repair of damaged cartilage. For decades, investigators have explored static joint contact stresses (under some more or less arbitrary condition) as a surrogate of the relevant mechanical history. Contact stresses have been estimated in vitro in many joints and in a number of species, although only rarely in vivo. Despite a number of widely varying techniques (and spatial resolutions) to measure these contact stresses, reported ranges of static peak normal stresses are relatively similar from joint to joint across species, and in the range of 0.5 to 5.0 MPa. This suggests vertebrate diarthrodial joints have evolved to achieve similar mechanical design criteria. Available evidence also suggests some disorders of cartilage deterioration are associated with somewhat higher peak pressures ranging from 1-20 MPa, but overlapping the range of normal pressures. Some evidence and considerable logic suggests static contact stresses per se do not predict cartilage responses, but rather temporal aspects of the contact stress history. Static contact stresses may therefore not be a reasonable surrogate for biomechanical studies. Rather, temporal and spatial aspects of the loading history undoubtedly induce beneficial and deleterious biological responses. Finally, since all articular cartilage experiences similar stresses, the concept of a "weight-bearing" versus a "non-weight-bearing" joint seems flawed, and should be abandoned. PMID:16089079

  7. Joint hypermobility syndrome pain

    Microsoft Academic Search

    Rodney Grahame

    2009-01-01

    Joint hypermobility syndrome (JHS) was initially defined as the occurrence of musculoskeletal symptoms in the presence of\\u000a joint laxity and hypermobility in otherwise healthy individuals. It is now perceived as a commonly overlooked, underdiagnosed,\\u000a multifaceted, and multisystemic heritable disorder of connective tissue (HDCT), which shares many of the phenotypic features\\u000a of other HDCTs such as Marfan syndrome and Ehlers-Danlos syndrome.

  8. Facets of career satisfaction for women physicians in the United States: a systematic review.

    PubMed

    Rizvi, Rabab; Raymer, Lindsay; Kunik, Mark; Fisher, Joslyn

    2012-01-01

    Women make up a growing proportion of the physician workforce, and their career satisfaction may affect their health. The authors hypothesized that many facets adversely affecting career satisfaction in women physicians were extrinsic, therefore, preventable or modifiable. The authors conducted a systematic review of the literature in English published through February 2010 to examine facets of career satisfaction of U.S. women physicians. The authors used the women physician AND job satisfaction OR career satisfaction Medical Subject Headings (MeSH) terms, and reviewed bibliographies of key articles to ensure inclusion of relevant studies. The authors used the "Strengthening the Reporting of Observation Studies in Epidemiology" quality tool. Of an initial 1,000 studies, only 30 met the inclusion criteria. Facets reported most frequently to influence career satisfaction for women physicians were income/prestige, practice characteristics, and personal/family characteristics. Overall, career satisfaction for women and men physicians was 73.4% (range = 56.4% to 90%) and 73.2% (range = 59% to 90%), respectively. When compared with men, women physicians were more concerned with perceived lack of time for relationships with patients, colleagues, and family; less satisfied with mentoring relationships and support from all sources; and less satisfied with career-advancement opportunities, recognition, and salary. Career satisfaction can affect health, as well as health and safety of patients. Many factors adversely affecting career satisfaction for women physicians are extrinsic and, therefore, modifiable. PMID:22591235

  9. Coherent, focus-corrected imaging of optical fiber facets using a single-pixel detector.

    PubMed

    Gordon, George S D; Feng, Feng; Kang, Qiongyue; Jung, Yongmin; Sahu, Jayanta; Wilkinson, Timothy

    2014-10-15

    A novel imaging technique that produces accurate amplitude and phase images of an optical fiber facet using only a phase-only liquid-crystal on silicon (LCOS) spatial light modulator (SLM) and a single-pixel detector is presented. The system can take images in two orthogonal polarizations and so provides a powerful tool for modal characterization of multimode fibers, which is of increasing importance due to their burgeoning use in telecommunications and medical applications. This technique first uses a simulated annealing algorithm to compute a hologram that collects light from a small region of the fiber facet. Next, the fiber facet is automatically brought into focus using adaptive aberration correction on the SLM. Finally, a common-path interferometer is created using the SLM, and the phase of the optical field at each pixel is determined. Finally, high-definition amplitude and phase images of a ring-core refractive index fiber are presented as a proof-of-principle demonstration of the technique. PMID:25361149

  10. (100) facets of ?-Al2O3: the active surfaces for alcohol dehydration reactions

    SciTech Connect

    Kwak, Ja Hun; Mei, Donghai; Peden, Charles HF; Rousseau, Roger J.; Szanyi, Janos

    2011-05-01

    Temperature programmed desorption (TPD) of ethanol, and methanol dehydration reaction were studied on ?-Al2O3 in order to identify the catalytic active sites for alcohol dehydration reactions. Two high temperature (> 473 K) desorption features were observed following ethanol adsorption. Samples calcined at T?473 K displayed a desorption feature in the 523-533 K temperature range, while those calcined at T ? 673 K showed a single desorption feature at 498 K. The switch from the high to low temperature ethanol desorption correlated well with the dehydroxylation of the (100) facets of ?-Al2O3 that was predicted at 550 K DFT calculations. Theoretical DFT simulations of the mechanism of dehydration. on clean and hydroxylated ?-Al2O3(100) surfaces, find that a concerted elimination of ethylene from an ethanol molecule chemisorbed at an Al3+ pentacoordinated site is the rate limiting step for catalytic cycle on both surfaces. Furthermore, titration of the pentacoordinate Al3+ sites on the (100) facets of ?-Al2O3 by BaO completely turned off the methanol dehydration reaction activity. These results unambiguously demonstrate that only the (100) facets on ?-Al2O3 are the catalytic active surfaces for alcohol dehydration.

  11. Ga-polar GaN nanocolumn arrays with semipolar faceted tips

    NASA Astrophysics Data System (ADS)

    Urban, A.; Malindretos, J.; Klein-Wiele, J.-H.; Simon, P.; Rizzi, A.

    2013-05-01

    Selective area growth of GaN nanocolumns (NCs) by molecular beam epitaxy on laser ablated pre-patterned GaN(0001) templates is shown to provide regular arrays of Ga-polar NCs. The Ga diffusion-assisted growth mechanism is analyzed and the experiments suggest that the effective growth conditions vary with the height of the NCs due to Ga diffusion on the mask and the NC sidewalls, ranging from N-rich up to stoichiometry. The obtained morphology with semipolar facets at the tip is discussed within the framework of equilibrium thermodynamics, which provides a consistent picture also for the growth of N-polar NCs with flat tips. The structural investigation reveals almost defect-free semipolar \\{1\\overline {1}02\\} GaN facets at the top of the NCs, which is known to be a promising way of producing templates for nanoscale semipolar GaN-based heterostructures. Almost no polarization discontinuity is expected for InxGa1-xN/GaN interfaces on such facets.

  12. Treating personality-relationship transactions with respect: narrow facets, advanced models, and extended time frames.

    PubMed

    Mund, Marcus; Neyer, Franz J

    2014-08-01

    Contrary to premises of dynamic transactionism, most studies investigating personality-relationship transaction only found personality effects on relationships but failed to find effects of relationship experiences on personality development. The current study reconsiders this issue in 3 ways. First, alongside the broad Big Five characteristics (Neuroticism, Extraversion, Openness, Agreeableness, and Conscientiousness), specific personality facets were considered to make comparisons with relationships more symmetric. Second, a recent extension of latent change modeling was applied allowing for a theoretically more appropriate model that compensates for the shortcomings of traditionally used cross-lagged panel or growth curve models. Third, personality-relationship transaction was studied from young adulthood to midlife using a 15-year longitudinal study with 654 German adults. Results showed patterns of personality-relationship transaction with the romantic partner, friends, kin, and other interaction partners. Specifically, the development of Neuroticism, Agreeableness, and Conscientiousness and their facets was closely interacting with partner and friend relationships, underlining the importance of these relationships for personality maturation during the adult years. We conclude that relationship effects have often been underestimated in previous studies. They are not bound to specific developmental periods, such as emerging adulthood, but their detection depends on the modeling approach and the analysis level (broad dimensions vs. facets). Relationship effects are most likely to occur in relationships that reflect self-selected life styles and circumstances. PMID:25090133

  13. High pressure ceramic joint

    DOEpatents

    Ward, M.E.; Harkins, B.D.

    1993-11-30

    Many recuperators have components which react to corrosive gases and are used in applications where the donor fluid includes highly corrosive gases. These recuperators have suffered reduced life, increased service or maintenance, and resulted in increased cost. The present joint when used with recuperators increases the use of ceramic components which do not react to highly corrosive gases. Thus, the present joint used with the present recuperator increases the life, reduces the service and maintenance, and reduces the increased cost associated with corrosive action of components used to manufacture recuperators. The present joint is comprised of a first ceramic member, a second ceramic member, a mechanical locking device having a groove defined in one of the first ceramic member and the second ceramic member. The joint and the mechanical locking device is further comprised of a refractory material disposed in the groove and contacting the first ceramic member and the second ceramic member. The present joint mechanically provides a high strength load bearing joint having good thermal cycling characteristics, good resistance to a corrosive environment and good steady state strength at elevated temperatures. 4 figures.

  14. Kinetically controlled synthesis of Pt-Cu alloy concave nanocubes with high-index facets for methanol electro-oxidation.

    PubMed

    Qi, Yue; Bian, Ting; Choi, Sang-Il; Jiang, Yingying; Jin, Chuanhong; Fu, Maoshen; Zhang, Hui; Yang, Deren

    2014-01-18

    Pt-Cu alloy concave nanocubes enclosed by high-index {511} facets were synthesized in high yields and exhibited substantially enhanced electrocatalytic properties for methanol oxidation relative to commercial Pt/C. PMID:24271020

  15. Hidden surface states at non-polar GaN 1010 facets: Intrinsic pinning of L. Lymperakis,1

    E-print Network

    Dunin-Borkowski, Rafal E.

    Hidden surface states at non-polar GaN ð1010Þ facets: Intrinsic pinning of nanowires L. Lymperakis on modified pseudopotentials find the upper (empty) surface state in the whole Brillouin zone (BZ) within

  16. Catastrophic optical degradation of the output facet of high-power single-transverse-mode diode lasers. 1. Physical model

    SciTech Connect

    Miftakhutdinov, D R; Bogatov, Alexandr P; Drakin, A E [P N Lebedev Physical Institute, Russian Academy of Sciences, Moscow (Russian Federation)

    2010-09-10

    The physical model of catastrophic optical degradation (COD) of the output facet of high-power single- transverse-mode diode lasers is developed. The model excels other models both in completeness of the physical analysis of the processes leading to COD and in allowance for design feature of lasers used to increase the COD threshold - protective coating of the output facet and current limitations near it. (lasers)

  17. Phase control of GaN on Si by nanoscale faceting in metalorganic vapor-phase epitaxy

    Microsoft Academic Search

    S. C. Lee; X. Y. Sun; S. D. Hersee; S. R. J. Brueck

    2004-01-01

    Phase stability of GaN on (111)–(001) nanoscale faceted Si is investigated. Nanoscale faceting (nanofaceting) is accomplished on a Si(001) substrate with interferometric lithography and anisotropic wet etching. By relying on the nucleation and associated lateral growth depending on orientation and crystal structure, spatial separation of a cubic-phase region from hexagonal-phase GaN regions which initiate on the facing Si(111) sidewalls of

  18. Metal Grating Patterning on Fiber Facets by UV-Based Nano Imprint and Transfer Lithography Using Optical Alignment

    Microsoft Academic Search

    Stijn Scheerlinck; Peter Dubruel; Peter Bienstman; Etienne Schacht; Dries Van Thourhout; Roel Baets

    2009-01-01

    UV-based nano imprint and transfer lithography (NITL) is proposed as a flexible, low cost and versatile approach for defining sub-micron metal patterns on optical fiber facets in a single-processing step. NITL relies on a specially prepared mold carrying the pattern that is to be transferred to the facet. The fiber's light-guiding properties allow control of the position of the metal

  19. Final Report for Project "Framework Application for Core-Edge Transport Simulations (FACETS)"

    SciTech Connect

    Estep, Donald [Colorado State University] [Colorado State University

    2014-01-17

    This is the final report for the Colorado State University Component of the FACETS Project. FACETS was focused on the development of a multiphysics, parallel framework application that could provide the capability to enable whole-device fusion reactor modeling and, in the process, the development of the modeling infrastructure and computational understanding needed for ITER. It was intended that FACETS be highly flexible, through the use of modern computational methods, including component technology and object oriented design, to facilitate switching from one model to another for a given aspect of the physics, and making it possible to use simplified models for rapid turnaround or high-fidelity models that will take advantage of the largest supercomputer hardware. FACETS was designed in a heterogeneous parallel context, where different parts of the application can take advantage through parallelism based on task farming, domain decomposition, and/or pipelining as needed and applicable. As with all fusion simulations, an integral part of the FACETS project was treatment of the coupling of different physical processes at different scales interacting closely. A primary example for the FACETS project is the coupling of existing core and edge simulations, with the transport and wall interactions described by reduced models. However, core and edge simulations themselves involve significant coupling of different processes with large scale differences. Numerical treatment of coupling is impacted by a number of factors including, scale differences, form of information transferred between processes, implementation of solvers for different codes, and high performance computing concerns. Operator decomposition involving the computation of the individual processes individually using appropriate simulation codes and then linking/synchronizing the component simulations at regular points in space and time, is the defacto approach to high performance simulation of multiphysics, multiscale systems. Various forms of operator decomposition are used in nearly all fusion simulations. However, operator decomposition generally has a complex effect on accuracy and stability of numerical simulations. Yet, these effects can be difficult to detect. The Colorado State University component of the FACETS team led by P. I. D. Estep was focused on analyzing the effects of operator decomposition on fusion simulations. The approach was based on a posteriori error analysis employing adjoint problems, computable residuals, and variational analysis to produce accurate computational error estimates for quantities of interest. Computable residuals are used to quantify the effects of various discretization choices. The generalized Greens function satisfying the adjoint problem quantities the effects of stability. Technical issues to be addressed included: (1) defining appropriate adjoint operators for operator decomposition discretizations; (2) determining the appropriate residuals for the multifaceted aspects involved with multiphysics discretizations; (3) producing the estimates within the computational framework of existing fusion codes; (4) carrying out the analysis for discretizations used in fusion simulations; and (5) devising efficient approaches to mitigating the effects of discretization. This report provides a summary of the accomplished research and a detailed description of personnel, activities, outcomes and achievements.

  20. Morphotectonic evolution of triangular facets and wine-glass valleys in the Noakoh anticline, Zagros, Iran: Implications for active tectonics

    NASA Astrophysics Data System (ADS)

    Bahrami, Shahram

    2012-07-01

    The Noakoh anticline is located in Kermanshah province and is part of the Simply Folded Belt of Zagros. Boundaries of 97 triangular facets and 67 wine-glass (W-G) valleys, which formed on anticline limbs, were delineated using Quickbird satellite imagery. The strata dip (D), area (A), base length (BL), topographic slope (S) of facets, the maximum width (M), outlet width (O) and ratio of maximum width to outlet width (W index) of W-G valleys were analysed in detail. Noakoh anticline was subdivided into 9 tectonic zones on the basis of dip, topographic slopes and width of limbs. Results show that there are strong positive correlations between means of D-BL and S-BL pairs. Poor positive correlations exist between means of D-A and S-A pairs. Among W-G valley metrics, the W index has strong relations with D and S parameters. Based on the results, steep facets with long bases and well developed W-G valleys with narrow outlets and wide upper parts are associated with more rotated limbs having steep slopes. Facets on the northeastern slope have more forest cover, micro-organism activity, karstic features and soil cover, whereas facets on relatively drier southwestern slope are characterized by physical weathering processes and minor karstic landforms. This study demonstrates that, apart from tectonic activity as a major control on the morphometry of facets and valleys, climate and slope aspect have also acted as secondary factors on the development of the studied landforms.

  1. First combined in vivo X-ray tomography and high-resolution molecular electron paramagnetic resonance (EPR) imaging of the mouse knee joint taking into account the disappearance kinetics of the EPR probe.

    PubMed

    Bézière, Nicolas; Decroos, Christophe; Mkhitaryan, Karen; Kish, Elizabeth; Richard, Frédéric; Bigot-Marchand, Stéphanie; Durand, Sylvain; Cloppet, Florence; Chauvet, Caroline; Corvol, Marie-Thérèse; Rannou, François; Xu-Li, Yun; Mansuy, Daniel; Peyrot, Fabienne; Frapart, Yves-Michel

    2012-06-01

    Although laboratory data clearly suggest a role for oxidants (dioxygen and free radicals derived from dioxygen) in the pathogenesis of many age-related and degenerative diseases (such as arthrosis and arthritis), methods to image such species in vivo are still very limited. This methodological problem limits physiopathologic studies about the role of those species in vivo, the effects of their regulation using various drugs, and the evaluation of their levels for diagnosis of degenerative diseases. In vivo electron paramagnetic resonance (EPR) imaging and spectroscopy are unique, noninvasive methods used to specifically detect and quantify paramagnetic species. However, two problems limit their application: the anatomic location of the EPR image in the animal body and the relative instability of the EPR probes. Our aim is to use EPR imaging to obtain physiologic and pathologic information on the mouse knee joint. This article reports the first in vivo EPR image of a small tissue, the mouse knee joint, with good resolution (? 160 ?m) after intra-articular injection of a triarylmethyl radical EPR probe. It was obtained by combining EPR and x-ray micro-computed tomography for the first time and by taking into account the disappearance kinetics of the EPR probe during image acquisition to reconstruct the image. This multidisciplinary approach opens the way to high-resolution EPR imaging and local metabolism studies of radical species in vivo in different physiologic and pathologic situations. PMID:22554486

  2. Dissimilar metals joint evaluation

    NASA Technical Reports Server (NTRS)

    Wakefield, M. E.; Apodaca, L. E.

    1974-01-01

    Dissimilar metals tubular joints between 2219-T851 aluminum alloy and 304L stainless steel were fabricated and tested to evaluate bonding processes. Joints were fabricated by four processes: (1) inertia (friction) weldings, where the metals are spun and forced together to create the weld; (2) explosive welding, where the metals are impacted together at high velocity; (3) co-extrusion, where the metals are extruded in contact at high temperature to promote diffusion; and (4) swaging, where residual stresses in the metals after a stretching operation maintain forced contact in mutual shear areas. Fifteen joints of each type were prepared and evaluated in a 6.35 cm (2.50 in.) O.D. size, with 0.32 cm (0.13 in.) wall thickness, and 7.6 cm (3.0 in) total length. The joints were tested to evaluate their ability to withstand pressure cycle, thermal cycle, galvanic corrosion and burst tests. Leakage tests and other non-destructive test techniques were used to evaluate the behavior of the joints, and the microstructure of the bond areas was analyzed.

  3. Acromioclavicular Joint Injuries

    PubMed Central

    Beim, Gloria M.

    2000-01-01

    Objective: To discuss the anatomy and biomechanics of the acromioclavicular (AC) joint, along with the clinical evaluation and treatment of an athlete with an AC joint injury. Data Sources: I searched MEDLINE from 1970 through 1999 under the key words “acromioclavicular joint,” “clavicle,” “acromioclavicular separation,” and “acromioclavicular dislocation.” Knowledge base was an additional source. Data Synthesis: AC joint injury is common in athletes and a source of significant morbidity, particularly for athletes in overhead sports. Because this injury can masquerade as other shoulder conditions, the examiner must understand the anatomy and biomechanics of the shoulder in order to perform a systematic clinical evaluation and identify the injury. Conclusions/Recommendations: Careful attention to the clinical evaluation allows the clinician to categorize the athlete's AC joint injury and institute appropriate treatment in a timely fashion, thus permitting the athlete to return to sport as quickly and safely as possible. ImagesFigure 1.Figure 2.Figure 3.Figure 4.Figure 5.Figure 6.Figure 7. PMID:16558638

  4. 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

  5. Robotic Bladder Joint

    NASA Technical Reports Server (NTRS)

    Robertson, Glen A.

    1995-01-01

    Reliable, lightweight robotic joint suitable for variety of applications, actuated hydraulically, without need for heavy mechanical cylinders or gears on joint itself. Includes two members; first member rotates about pin at end of second member. Includes cam, over which tension line stretched. Ends of tension line anchored at end of second member opposite end that holds pin. Bladder placed on each side of second member, squeezed between second member and tension line. Pressures and/or amounts of fluid in bladders controlled by use of conventional equipment like pumps, valves, and reservoirs. Bladder on one side inflated more than on other side; greater inflation on one side causes greater stretching of tension line on that side. Greater tension pulls on cam, turning first member toward that side. Angle of joint controlled by controlling differential inflation of two bladders.

  6. Quick acting gimbal joint

    NASA Technical Reports Server (NTRS)

    Wood, William B. (inventor); Krch, Gary D. (inventor)

    1993-01-01

    The present invention relates to an adjustable linkage assembly for selectively retaining the position of one member pivotable with respect to another member. More specifically, the invention relates to a linkage assembly commonly referred to as a gimbal joint, and particularly to a quick release or quick acting gimbal joint. The assembly is relatively simple in construction, compact in size, and has superior locking strength in any selected position. The device can be quickly and easily actuated, without separate tooling, by inexperienced personnel or by computer controlled equipment. It also is designed to prevent inadvertent actuation.

  7. Joint for deployable structures

    NASA Technical Reports Server (NTRS)

    Craighead, N. D., II; Preliasco, R. J.; Hult, T. D. (inventors)

    1985-01-01

    A joint is described for connecting a pair of beams to pivot them between positions in alignment or beside one another, which is of light weight and which operates in a controlled manner. The joint includes a pair of fittings and at least one center link having opposite ends pivotally connected to opposite fittings and having axes that pass through centerplates of the fittings. A control link having opposite ends pivotally connected to the different fittings controls their relative orientations, and a toggle assemly holds the fittings in the deployed configuration wherein they are aligned. The fittings have stops that lie on one side of the centerplane opposite the toggle assembly.

  8. Prosthetic Joint Infection

    PubMed Central

    Tande, Aaron J.

    2014-01-01

    SUMMARY Prosthetic joint infection (PJI) is a tremendous burden for individual patients as well as the global health care industry. While a small minority of joint arthroplasties will become infected, appropriate recognition and management are critical to preserve or restore adequate function and prevent excess morbidity. In this review, we describe the reported risk factors for and clinical manifestations of PJI. We discuss the pathogenesis of PJI and the numerous microorganisms that can cause this devastating infection. The recently proposed consensus definitions of PJI and approaches to accurate diagnosis are reviewed in detail. An overview of the treatment and prevention of this challenging condition is provided. PMID:24696437

  9. Prosthetic joint infection.

    PubMed

    Tande, Aaron J; Patel, Robin

    2014-04-01

    Prosthetic joint infection (PJI) is a tremendous burden for individual patients as well as the global health care industry. While a small minority of joint arthroplasties will become infected, appropriate recognition and management are critical to preserve or restore adequate function and prevent excess morbidity. In this review, we describe the reported risk factors for and clinical manifestations of PJI. We discuss the pathogenesis of PJI and the numerous microorganisms that can cause this devastating infection. The recently proposed consensus definitions of PJI and approaches to accurate diagnosis are reviewed in detail. An overview of the treatment and prevention of this challenging condition is provided. PMID:24696437

  10. New Joint Sealants. Criteria, Design and Materials.

    ERIC Educational Resources Information Center

    Building Research Inst., Inc., Washington, DC.

    Contents include--(1) sealing concrete joints, (2) sealing glass and metal joints, (3) metal and glass joint sealants from a fabricator's viewpoint, (4) a theory of adhesion for joint sealants, (5) geometry of simple joint seals under strain, (6) joint sealant specifications from a manufacturer's viewpoint, (7) joint sealant requirements from an…

  11. True Upward Adatom Diffusion and Faceting in fcc metal (110) homoepitaxy

    NASA Astrophysics Data System (ADS)

    Buatier de Mongeot, Francesco

    2004-03-01

    Recent studies of Ge heteroepitaxial growth on Si(100) have led to the discovery of an intriguing bimodal growth mode, characterised by the coexistence of smaller hut islands and much larger domes. Efforts aimed to understand the microscopic mechanisms involved have so far been focused predominantly on the role of the thermodynamic driving force associated with stress. Here we report on the observation of bimodal growth in an entirely unexpected system, homoepitaxial growth of Al on Al(110), characterised by the coexistence of smaller mound islands and tenfold taller nanocrystals with well-defined facets (the huts). Whereas the formation of the mounds results from kinetic roughening due to slow downward adatom diffusion at step edges, the formation of the huts demands atom extraction from the mounds and true upward diffusion of such atoms through the (110) terraces onto the facets serving as kinetic traps. A critical role in the faceting instability, is found to be played by the surprisingly low activation barriers for adatom ascent at step edges and island corners(F.Buatier de Mongeot, W.Zhu, A.Molle, R.Buzio, C.Boragno, U. Valbusa, E.G.Wang, Z.Zhang, Physical Review Letters 91, 016102 (2003)),(Physics News Update, AIP, Number 643,2003 Mountain climbing atoms (http://www.aip.org/enews/physnews/2003/split/643-2.html)). Extensions of the results to other related systems will be presented, in particular for the fcc(110) class of substrates Cu, Pb, Ag as well as for heteroepitaxyal systems like Co/Cu(110).

  12. CoMAGC: a corpus with multi-faceted annotations of gene-cancer relations

    PubMed Central

    2013-01-01

    Background In order to access the large amount of information in biomedical literature about genes implicated in various cancers both efficiently and accurately, the aid of text mining (TM) systems is invaluable. Current TM systems do target either gene-cancer relations or biological processes involving genes and cancers, but the former type produces information not comprehensive enough to explain how a gene affects a cancer, and the latter does not provide a concise summary of gene-cancer relations. Results In this paper, we present a corpus for the development of TM systems that are specifically targeting gene-cancer relations but are still able to capture complex information in biomedical sentences. We describe CoMAGC, a corpus with multi-faceted annotations of gene-cancer relations. In CoMAGC, a piece of annotation is composed of four semantically orthogonal concepts that together express 1) how a gene changes, 2) how a cancer changes and 3) the causality between the gene and the cancer. The multi-faceted annotations are shown to have high inter-annotator agreement. In addition, we show that the annotations in CoMAGC allow us to infer the prospective roles of genes in cancers and to classify the genes into three classes according to the inferred roles. We encode the mapping between multi-faceted annotations and gene classes into 10 inference rules. The inference rules produce results with high accuracy as measured against human annotations. CoMAGC consists of 821 sentences on prostate, breast and ovarian cancers. Currently, we deal with changes in gene expression levels among other types of gene changes. The corpus is available at http://biopathway.org/CoMAGCunder the terms of the Creative Commons Attribution License ( http://creativecommons.org/licenses/by/2.0). Conclusions The corpus will be an important resource for the development of advanced TM systems on gene-cancer relations. PMID:24225062

  13. Hemorrhagic lumbar facet cysts accompanying a spinal subdural hematoma at the same level.

    PubMed

    Ikeda, Osamu; Minami, Norihiko; Yamazaki, Masashi; Koda, Masao; Morinaga, Tatsuo

    2015-03-01

    Context We present a rare and interesting case of hemorrhagic lumbar facet cysts accompanying a spinal subdural hematoma at the same level suggesting a possible mechanism by which spinal subdural hematomas can arise. Findings A 71-year-old man presented with persistent sciatic pain and intermittent claudication. Magnetic resonance imaging demonstrated a multilocular mass lesion that showed high signal intensity in both T1- and T2-weighted images, and was located both inside and outside of the spinal canal. Computed tomographic myelography showed a cap-shaped block of the dural tube at L5 and computed tomography with L5-S facet arthrography demonstrated cystic masses. The patient was diagnosed with lumbar radiculopathy caused by hemorrhagic facet cysts, and then progressed to surgical treatment. Surgery revealed that the cysts contained blood clots, and intraoperative findings that the inside of the dural tube appeared blackish and that the dural tube was tensely ballooned after removal of the cysts led us to explorative durotomy. The durotomy demonstrated concentrated old blood pooling both in the dorsal and ventral subdural space, and these spaces were subsequently drained. After surgery, his sciatic pain and intermittent claudication resolved. There was no evidence of cyst mass recurrence at 2 years of follow-up. Conclusion We propose a newly described mechanism for the formation of spinal subdural hematomas. We recommend surgeons be alert to epidural lesions causing repeated acute compression of the dural tube, which can cause spinal subdural hematoma, and consider the possible coexistence of these lesions in diagnosis and strategic surgical decisions. PMID:24976137

  14. Final Report for the "Fusion Application for Core-Edge Transport Simulations (FACETS)"

    SciTech Connect

    Cary, John R; Kruger, Scott

    2014-10-02

    The FACETS project over its lifetime developed the first self-consistent core-edge coupled capabilities, a new transport solver for modeling core transport in tokamak cores, developed a new code for modeling wall physics over long time scales, and significantly improved the capabilities and performance of legacy components, UEDGE, NUBEAM, GLF23, GYRO, and BOUT++. These improved capabilities leveraged the team’s expertise in applied mathematics (solvers and algorithms) and computer science (performance improvements and language interoperability). The project pioneered new methods for tackling the complexity of simulating the concomitant complexity of tokamak experiments.

  15. Facet and in-plane crystallographic orientations of GaN nanowires grown on Si(111).

    PubMed

    Largeau, L; Dheeraj, D L; Tchernycheva, M; Cirlin, G E; Harmand, J C

    2008-04-16

    We have determined the in-plane orientation of GaN nanowires relative to the Si (111) substrate on which they were grown. We used x-ray diffraction pole figure measurements to evidence two types of crystallographic orientation, all the nanowires having [Formula: see text] lateral facets. The proportion of these two orientations was determined and shown to be influenced by the pre-deposition of Al(Ga)N intermediate layers. In the main orientation, the GaN basal [Formula: see text] directions are aligned with the [Formula: see text] directions. This orientation corresponds to an in-plane coincidence of GaN and Si lattices. PMID:21825628

  16. Clinical evaluation and surgical decision making for patients with lumbar discogenic pain and facet syndrome.

    PubMed

    Tessitore, Enrico; Molliqaj, Granit; Schatlo, Bawarjan; Schaller, Karl

    2015-05-01

    In industrialized countries, more than two thirds of the population suffers from low back pain (LBP) in their lifetime. LBP associated with lumbar disc herniation, stenosis, and instability is a well-known and documented entity. On the other hand, the lumbar discogenic pain and facet syndrome are difficult to be clearly identified, and they are not always detectable by imaging. This article describes the causes of these painful syndromes, which are typically without radicular component, explains the modern diagnostic procedures, and provides guidelines for surgical decision making. PMID:24801263

  17. Polish-like facet preparation via dicing for silica integrated optics

    NASA Astrophysics Data System (ADS)

    Carpenter, L. G.; Rogers, H. L.; Holmes, C.; Gates, J. C.; Smith, P. G. R.

    2013-03-01

    Preparation of high quality facets for low-loss coupling is a significant production issue for integrated photonics, usually requiring time consuming lapping and polishing. Recently, the development of precision dicing saws with diamond impregnated blades has allowed the achievement of optical grade surfaces in optical materials based on dicing alone. In this report we investigate the optimization dicing conditions to achieve optical quality surfaces in a silica-on-silicon planar substrate and show what can be achieved by correct selection of machining parameters.

  18. Faceting via correlated disorder of a stochastically growing interface or domain boundary

    E-print Network

    Lyuksyutov, Igor F.; Everts, HU.

    1998-01-01

    superconductor with so-called columnar ~correlated! dis- order. We discuss this relation briefly in Sec. V. Faceting via correlated disorder of a stochasticall Igor F. Lyuksyuto Department of Physics, Texas A&M University H.-U. Institut fu?r Theoretische... the renormalization-group equations for Eq. ~1! we use the ap- proach which applied by Kardar, Parisi, and Zhang2 to the 1958 IGOR F. LYUKSYUTO KPZ equation. Using the standard procedure,2 we obtain the following flow equations: d dl n5F z221Ad 22d 4d l 2 G...

  19. Joints in a Cornstarch Analog

    NSDL National Science Digital Library

    Juliet Crider

    Joints are very important to problems in applied geology (fluid flow, slope stability), but three-dimensional exposures of simple joint sets are not readily accessible from my campus. I developed this exercise based on the experiments of Miller (2001) to give students hands-on practice describing and interpreting joints. For the exercise, I prepare a cornstarch-water mixture a few days in advance and pour it into plastic petri dishes. I add a "flaw" to each dish (typically a small pebble). As the cornstarch dries, vertical joints develop. In class, each group of 3-4 students is provided a petri dish of desiccated cornstarch. Students are asked to draw a map of the joints, paying particular attention to intersection angles. (The joints curve to intersect at 90 degrees.) They determine relative ages of the joints using abutting relationships. (Typically 3-6 generations of joints.) Students next dissect the sample and describe the surface textures of the larger joints and the location of the flaw. The cornstarch produces beautiful plumose structure (hackles). Students then interpret the joint propagation direction from the surface textures, and note the origin of the joint. (Typically, a first- or second-generation joint initiates at the flaw.) Students discuss the role of flaws in the initiation of joints in their groups.

  20. CARTILAGE, BONES, AND JOINTS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cartilage is a special type of connective tissue that is of extreme importance in embryonic development, serving as the model upon which true bone is later formed. Cartilage also persists in adult animals, primarily as articular cartilage which cushions the interface between adjacent bones or joint...

  1. Evolving flexible joint morphologies

    Microsoft Academic Search

    Jared M. Moore; Philip K. McKinley

    2012-01-01

    Transferring virtual robotic designs into physical robots has become possible with the development of 3D printers. Accurately simulating the performance of real robots in a virtual environment requires modeling a variety of conditions, including the physical composition of the robots themselves. In this paper, we investigate how modeling material flexibility through the use of a passive joint affects the resulting

  2. Biologics — beyond the joints

    Microsoft Academic Search

    Zoltán Szekanecz; Sándor Szántó; Zoltán Szabó; Andrea Váncsa; Szilvia Szamosi; Nóra Bodnár; Gabriella Szücs

    2010-01-01

    Biologics including tumor necrosis factor ? (TNF-?), interleukin-6 receptor (IL-6R), T and B cell inhibitors are very effective therapeutic agents for the treatment of arthritides. These compounds effectively improve articular symptoms and inhibit joint damage. In this respect, there are no major differences in the efficacy of the available biologics. However, many arthritis patients also exert extra-articular features, systemic manifestations

  3. Dolphin Skeleton (Gliding Joint)

    NSDL National Science Digital Library

    Ketan Patel (California State University, Fullerton; )

    2007-07-14

    The dolphin is built to be sleek. Its body is made of almost entirely backbone (a gliding joint) which makes it very flexible under water. The ribs protect the inner organs of the dolphin and the tail beats from side to side, thrusting the animal forward.

  4. LARP Joint IR studies

    E-print Network

    Zlobin, A V

    2008-01-01

    LARP initiated Joint IR Studies (JIRS) in October 2007 (FY2008) to coordinate efforts related to the LHC Phase I and II upgrades previously situated either in Accelerator Systems or in Magnet Systems. This note outlines JIRS goals, main directions and milestones.

  5. Dual-Eccentric Clevis Joint

    NASA Technical Reports Server (NTRS)

    Fairbank, Diana L.; Sertich, John J.

    1996-01-01

    Redesigned clevis joint incorporates dual mating eccentric cylindrical bushings to accommodate dimensional tolerances. Eliminates need for combination of oppositely threaded collar and bushing and makes overall joint hardware fit within available space.

  6. Parallel Syndromes: Two Dimensions of Narcissism and the Facets of Psychopathic Personality in Criminally-Involved Individuals

    PubMed Central

    2012-01-01

    Little research has examined different dimensions of narcissism that may parallel psychopathy facets in criminally-involved individuals. The present study examined the pattern of relationships between grandiose and vulnerable narcissism, assessed using the Narcissistic Personality Inventory-16 and the Hypersensitive Narcissism Scale, respectively, and the four facets of psychopathy (interpersonal, affective, lifestyle, and antisocial) assessed via the Psychopathy Checklist: Screening Version (PCL:SV). As predicted, grandiose and vulnerable narcissism showed differential relationships to psychopathy facets, with grandiose narcissism relating positively to the interpersonal facet of psychopathy and vulnerable narcissism relating positively to the lifestyle facet of psychopathy. Paralleling existing psychopathy research, vulnerable narcissism showed stronger associations than grandiose narcissism to 1) other forms of psychopathology, including internalizing and substance use disorders, and 2) self- and other-directed aggression, measured using the Life History of Aggression and the Forms of Aggression Questionnaire. Grandiose narcissism was nonetheless associated with social dysfunction marked by a manipulative and deceitful interpersonal style and unprovoked aggression. Potentially important implications for uncovering etiological pathways and developing treatment interventions for these disorders in externalizing adults are discussed. PMID:22448731

  7. Determination of Parachute Joint Factors using Seam and Joint Testing

    NASA Technical Reports Server (NTRS)

    Mollmann, Catherine

    2015-01-01

    This paper details the methodology for determining the joint factor for all parachute components. This method has been successfully implemented on the Capsule Parachute Assembly System (CPAS) for the NASA Orion crew module for use in determining the margin of safety for each component under peak loads. Also discussed are concepts behind the joint factor and what drives the loss of material strength at joints. The joint factor is defined as a "loss in joint strength...relative to the basic material strength" that occurs when "textiles are connected to each other or to metals." During the CPAS engineering development phase, a conservative joint factor of 0.80 was assumed for each parachute component. In order to refine this factor and eliminate excess conservatism, a seam and joint testing program was implemented as part of the structural validation. This method split each of the parachute structural joints into discrete tensile tests designed to duplicate the loading of each joint. Breaking strength data collected from destructive pull testing was then used to calculate the joint factor in the form of an efficiency. Joint efficiency is the percentage of the base material strength that remains after degradation due to sewing or interaction with other components; it is used interchangeably with joint factor in this paper. Parachute materials vary in type-mainly cord, tape, webbing, and cloth -which require different test fixtures and joint sample construction methods. This paper defines guidelines for designing and testing samples based on materials and test goals. Using the test methodology and analysis approach detailed in this paper, the minimum joint factor for each parachute component can be formulated. The joint factors can then be used to calculate the design factor and margin of safety for that component, a critical part of the design verification process.

  8. Cellular Pressure-Actuated Joint

    NASA Technical Reports Server (NTRS)

    McGuire, John R.

    2003-01-01

    A modification of a pressure-actuated joint has been proposed to improve its pressure actuation in such a manner as to reduce the potential for leakage of the pressurizing fluid. The specific joint for which the modification is proposed is a field joint in a reusable solid-fuel rocket motor (RSRM), in which the pressurizing fluid is a mixture of hot combustion gases. The proposed modification could also be applicable to other pressure-actuated joints of similar configuration.

  9. Joint Seminar Risk Management Institute &

    E-print Network

    Chaudhuri, Sanjay

    Joint Seminar Risk Management Institute & Department of Mathematics Details of Seminar Date empirical phenomena of the negative variance risk premium and implied volatility smirk if market into account. This is a joint work with Eric C. Chang and Huimin Zhao. Risk Management Institute Joint Seminar

  10. Double slotted socket spherical joint

    DOEpatents

    Bieg, Lothar F. (Albuquerque, NM); Benavides, Gilbert L. (Albuquerque, NM)

    2001-05-22

    A new class of spherical joints is disclosed. These spherical joints are capable of extremely large angular displacements (full cone angles in excess of 270.degree.), while exhibiting no singularities or dead spots in their range of motion. These joints can improve or simplify a wide range of mechanical devices.

  11. Phase 1 Program Joint Report

    NASA Technical Reports Server (NTRS)

    Nield, George C. (Editor); Vorobiev, Pavel Mikhailovich (Editor)

    1999-01-01

    This report consists of inputs from each of the Phase I Program Joint Working Groups. The Working Groups were tasked to describe the organizational structure and work processes that they used during the program, joint accomplishments, lessons learned, and applications to the International Space Station Program. This report is a top-level joint reference document that contains information of interest to both countries.

  12. Economical Joint for Truss Structures

    NASA Technical Reports Server (NTRS)

    Moore, Carleton J.

    1987-01-01

    Mass-produced flat parts easily assembled. Joint for three-dimensional truss made of simple die-cutplates and inexpensive fasteners. Each truss joint consists of two identical interlocking plates bolted, welded, or glued together. Truss struts bolted to joint through holes in plate. Alternatively, ends of struts forked so that they slip over plates and fastened to them by bolts or pins.

  13. The Challenges of Joint Attention

    Microsoft Academic Search

    Frederic Kaplan; Verena V. Hafner

    2004-01-01

    This paper discusses the concept of joint at- tention and the dierent skills underlying its development. We argue that joint attention is much more than gaze following or simul- taneous looking because it implies a shared intentional relation to the world. The current state-of-the-art in robotic and computational models of the dierent prerequisites of joint attention is discussed in relation

  14. Enabling multi-faceted measures of success for protected area management in Trinidad and Tobago.

    PubMed

    Granderson, Ainka A

    2011-08-01

    A key challenge has been to define and measure "success" in managing protected areas. A case study was conducted of efforts to evaluate the new protected area management system in Trinidad and Tobago using a participatory approach. The aim of the case study was to (1) examine whether stakeholder involvement better captures the multi-faceted nature of success and (2) identify the role and influence of various stakeholder groups in this process. An holistic and systematic framework was developed with stakeholder input that facilitated the integration of expert and lay knowledge, a broad emphasis on ecological, socio-economic, and institutional aspects, and the use of both quantitative and qualitative data allowing the evaluation to capture the multi-faceted nature and impacts of protected area management. Input from primary stakeholders, such as local communities, was critical as they have a high stake in protected area outcomes. Secondary and external stakeholders, including government agencies, non-governmental organizations, academia and the private sector, were also important in providing valuable technical assistance and serving as mediators. However, a lack of consensus over priorities, politics, and limited stakeholder capacity and data access pose significant barriers to engaging stakeholders to effectively measure the management success of protected areas. PMID:21555042

  15. Facet-dependent optical properties of polyhedral Au-Cu?O core-shell nanocrystals.

    PubMed

    Yang, Yu-Chen; Wang, Hsiang-Ju; Whang, Jennifer; Huang, Jer-Shing; Lyu, Lian-Ming; Lin, Po-Heng; Gwo, Shangjr; Huang, Michael H

    2014-04-21

    We fabricated Au-Cu?O core-shell octahedra, cuboctahedra, and nanocubes having sizes of 90-220 nm using 50 nm octahedral cores. The smaller particle sizes minimize the strong light scattering features from the Cu?O shells and enable the surface plasmon resonance (SPR) absorption band of the gold cores to be clearly identified. Beyond a lower shell thickness limit, the SPR band positions of the gold cores are independent of the shell thickness, but are strongly dependent on the exposed particle surfaces. The plasmonic band red-shifts from Au-Cu?O octahedra to cuboctahedra and nanocubes, and differs by as much as 26 nm between the octahedra and the nanocubes. The same facet-dependent optical effects were observed using larger octahedral gold cores and cubic gold cores. In contrast, simulation spectra show progressively red-shifted SPR band positions with increasing shell thickness. The Cu?O shells are also found to exhibit facet-dependent optical behavior. These nanocrystals can respond to changes in the solvent environment such as solvents with different refractive indices, indicating that the plasmonic field of the gold cores can extend beyond the particle surfaces despite the presence of thick shells. Plane-selective spectral responses to low concentrations of surfactants were also recorded. PMID:24622737

  16. Computed tomography-guided percutaneous facet screw fixation in the lumbar spine. Technical note.

    PubMed

    Kang, Ho Yeong; Lee, Sang-Ho; Jeon, Sang Hyeop; Shin, Song-Woo

    2007-07-01

    The authors describe a new minimally invasive technique for posterior supplementation using percutaneous translaminar facet screw (TFS) fixation with computed tomography (CT) guidance. Oblique axial images were used to determine facet screw fixation sites. After the induction of local anesthesia and conscious sedation, a guide pin was inserted and guided with a laser mounted on the CT gantry. Cannulated TFSs were placed via a percutaneous approach. From December 2002 to August 2003, 18 patients underwent CT-guided TFS. In 17 of these patients this procedure was supplementary to anterior lumbar interbody fusion, which had been performed several days earlier; in the remaining patient, CT-guided TFS fixation was undertaken as the primary therapy. Twelve patients had painful degenerative disc disease or unstable degenerative spondylolisthesis, three had infections, and three had deformities. All screws were inserted accurately and there were no complications. This new minimally invasive surgical technique may offer an alternative to pedicle screw fixation as a method of posterior supplementation. PMID:17633496

  17. Multi-faceted Rasch measurement and bias patterns in EFL writing performance assessment.

    PubMed

    He, Tung-Hsien; Gou, Wen Johnny; Chien, Ya-Chen; Chen, I-Shan Jenny; Chang, Shan-Mao

    2013-04-01

    This study applied multi-faceted Rasch measurement to examine rater bias in the assessment of essays written by college students learning English as a foreign language. Four raters who had received different academic training from four distinctive disciplines applied a six-category rating scale to analytically rate essays on an argumentative topic and on a descriptive topic. FACETS, a Rasch computer program, was utilized to pinpoint bias patterns by analyzing the rater-topic, rater-category, and topic-category interactions. Results showed: argumentative essays were rated more severely than were descriptive essays; the linguistics-major rater was the most lenient rater, while the literature-major rater was the severest one; and the category of language use received the severest ratings, whereas content was given the most lenient ratings. The severity hierarchies for raters, essay topics, and rating categories suggested that raters' academic training and their perceptions of the importance of categories were associated with their bias patterns. Implications for rater training are discussed. PMID:23833876

  18. Faceting of Nanoscale Pt and Au Particles for Applications in Catalysis

    SciTech Connect

    Richards, R. M.; Leong, J.; Dinh, H.; Pivovar, B.

    2012-01-01

    In an effort to reduce the world's dependence on fossil fuels as well as lower green house gas emissions, proton exchange membrane fuel cells (PEMFC) have been considered by many as a prime candidate for both mobile and stationary alternative energy sources. The principal limiting factor for efficiency in fuel cells is the oxygen reduction reaction (ORR) which is driven by platinum based catalyst materials. Numerous methods have been developed to synthesize particles that make more efficient use of the active surfaces by tuning shapes, sizes and facets. For example, it was recently demonstrated that selectivity can be tuned by controlling particle shape in the case of promoting trans olefin isomerization to their cis counterparts using close-packed Pt (111), Pt (557) and Pt (100) surfaces as opposed to a more open Pt (110), which favored the trans-counterparts. Furthermore, it has been reported that certain facets exhibit improved ORR activity while others may decrease activity at the bulk phase single crystal level. Here, we will present a study of various wet chemical reduction methods targeting specific morphologies and the resulting electrochemical activity. Determining the effects of synthetic parameters on the final product via transmission electron microscopy (TEM), small angle x-ray scattering (SAXS) and wide angle x-ray scattering (WAXS) provides mechanistic insight on growth kinetics, while electrochemical studies correlate physical properties to performance. Understanding structure and activity relationships will allow us to intuitively design next generation materials with enhanced properties.

  19. Development of a new modelling tool (FACET) to assess exposure to chemical migrants from food packaging.

    PubMed

    Oldring, P K T; O'Mahony, C; Dixon, J; Vints, M; Mehegan, J; Dequatre, C; Castle, L

    2014-01-01

    The approach used to obtain European Union-wide data on the usage and concentration of substances in different food packaging materials is described. Statistics were collected on pack sizes and market shares for the different materials used to package different food groups. The packaging materials covered were plastics (both flexible and rigid), metal containers, light metal packaging, paper and board, as well as the adhesives and inks used on them. An explanation as to how these data are linked in various ways in the FACET exposure modelling tool is given as well as an overview of the software along with examples of the intermediate tables of data. The example of bisphenol A (BPA), used in resins that may be incorporated into some coatings for canned foodstuffs, is used to illustrate how the data in FACET are combined to produce concentration distributions. Such concentration distributions are then linked probabilistically to the amounts of each food item consumed, as recorded in national food consumption survey diaries, in order to estimate exposure to packaging migrants. Estimates of exposure are at the level of the individual consumer and thus can be expressed for various percentiles of different populations and subpopulations covered by the national dietary surveys. PMID:24215584

  20. Broad bandwidth or high fidelity? Evidence from the structure of genetic and environmental effects on the facets of the five factor model.

    PubMed

    Briley, Daniel A; Tucker-Drob, Elliot M

    2012-09-01

    The Five Factor Model of personality is well-established at the phenotypic level, but much less is known about the coherence of the genetic and environmental influences within each personality domain. Univariate behavioral genetic analyses have consistently found the influence of additive genes and nonshared environment on multiple personality facets, but the extent to which genetic and environmental influences on specific facets reflect more general influences on higher order factors is less clear. We applied a multivariate quantitative-genetic approach to scores on the CPI-Big Five facets for 490 monozygotic and 317 dizygotic twins who took part in the National Merit Twin Study. Our results revealed a complex genetic structure for facets composing all five factors, with both domain-general and facet-specific genetic and environmental influences. For three of the Big Five domains, models that required common genetic and environmental influences on each facet to occur by way of effects on a higher order trait did not fit as well as models allowing for common genetic and environmental effects to act directly on the facets. These results add to the growing body of literature indicating that important variation in personality occurs at the facet level which may be overshadowed by aggregating to the trait level. Research at the facet level, rather than the factor level, is likely to have pragmatic advantages in future research on the genetics of personality. PMID:22695681

  1. Anatomic Facet Replacement System (AFRS) Restoration of Lumbar Segment Mechanics to Intact: A Finite Element Study and In Vitro Cadaver Investigation

    PubMed Central

    Mehta, Ankit; Jangra, Jayant; Faizan, Ahmed; Kiapour, Ali; Hoy, Robert W.; Fauth, Andrew R.

    2007-01-01

    Background Many decompression procedures involve complete or partial facetectomy. Spinal fusion usually stabilizes the motion segment after complete facetectomies. However, problems with fusion, such as adjacent-level degeneration, have increased interest in motion- preservation technologies. Facet arthroplasty may become an important posterior motion-preservation device, but its biomechanical literature is sparse. Methods We conducted an in vitro investigation and finite element study to compare the biomechanical effects of an artificial facet system to the intact spine. In the in vitro study, we tested human osteo-ligamentous segments (L3-S1) in intact, injured, and artificial facet–repaired conditions. For the finite element study, we used a 3-dimensional ligamentous L3-S1 segment model. We simulated destabilization in the intact model by removing the facets across the L4-L5 functional unit, then repaired it with appropriately sized facet implants and compared the ranges of motion, facet loads, disc pressures, and device loads. We also analyzed a finite element model with a rigid posterior pedicle-rod fixation system. We subjected the cadaveric specimens and the models to 400 N of follower load plus a 10 Nm moment in extension, flexion, bending, and rotation. We used a novel technique to apply the follower load in the finite element models such that preload induced minimal vertebral rotation during the range of motion. Results The predicted ranges of motion for the intact and implanted models were consistent with cadaver data. After destabilization and facet replacement, the artificial facet system restored motion in all loading modes to intact values. The implant facet loads were similar to intact facet loads in extension and axial rotation, but less in lateral bending. The intradiscal pressure at the implanted level for the facet replacement device was similar to the intact pressure, whereas with the rigid system the intradiscal pressure was up to 70% less than the intact pressure. The maximum von-Mises stress predicted in the facet replacement construct was 85 MPa in extension at the bone–pedicle screw interface, compared with 174 MPa in the rigid system. Contact stresses at implant mating surfaces were minimal. Conclusions The artificial facet system replicated natural facet kinematics. The cadaveric ranges of motion and the predicted finite element–based data indicated that the implant can “restore” the normal function of the segment after artificial facet replacement. Clinical Relevance Compared to rigid posterior pedicle-rod fixation, the artificial facet system restored the intact mechanics at the implanted level and may prevent adjacent-level degeneration.

  2. Cellular aspects of the development of diarthrodial joints and articular cartilage.

    PubMed Central

    Archer, C W; Morrison, H; Pitsillides, A A

    1994-01-01

    There have been many reports on the histological development of mammalian diarthrodial or synovial joints. While these are useful for comparative purposes, they tell us little of the cellular basis of joint morphogenesis which must underlie a number of morphogenetic defects. The process of joint morphogenesis is complex and can be subdivided into a number of facets and this report will focus on 2 of them. First, the process of joint cavitation in the chick metatarsophalangeal joint, where we propose that the selective secretion of hyaluronan into the presumptive cavity plays a central role. Secondly, the development of articular cartilage where we have used the South American opossum Monodelphis domestica as a model for mammalian development. Like most marsupials, the young are born at a much earlier developmental stage than eutherian mammals. Using antibodies which detect proliferating chondrocytes and those synthesising insulin-like growth factors 1 and 2 and insulin-like growth factor 1 binding protein, we report that the majority of growth (as assessed by these indicators) appears appositional. Images Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 PMID:7928634

  3. 49 CFR 213.121 - Rail joints.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...Transportation 4 2011-10-01 2011-10-01 false Rail joints. 213.121 Section 213.121 Transportation...SAFETY STANDARDS Track Structure § 213.121 Rail joints. (a) Each rail joint, insulated joint, and compromise...

  4. 49 CFR 213.121 - Rail joints.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...Transportation 4 2014-10-01 2014-10-01 false Rail joints. 213.121 Section 213.121 Transportation...SAFETY STANDARDS Track Structure § 213.121 Rail joints. (a) Each rail joint, insulated joint, and compromise...

  5. 49 CFR 213.121 - Rail joints.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...Transportation 4 2012-10-01 2012-10-01 false Rail joints. 213.121 Section 213.121 Transportation...SAFETY STANDARDS Track Structure § 213.121 Rail joints. (a) Each rail joint, insulated joint, and compromise...

  6. 49 CFR 213.121 - Rail joints.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...Transportation 4 2010-10-01 2010-10-01 false Rail joints. 213.121 Section 213.121 Transportation...SAFETY STANDARDS Track Structure § 213.121 Rail joints. (a) Each rail joint, insulated joint, and compromise...

  7. 49 CFR 213.121 - Rail joints.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...Transportation 4 2013-10-01 2013-10-01 false Rail joints. 213.121 Section 213.121 Transportation...SAFETY STANDARDS Track Structure § 213.121 Rail joints. (a) Each rail joint, insulated joint, and compromise...

  8. Improved high-temperature gimbal joint

    NASA Technical Reports Server (NTRS)

    Winemiller, J. R.; Yee, S. T.; Neal, B. H.

    1972-01-01

    Development and characteristics of bellows gimbal joint for reduction of thermal stress effects are discussed. Reactions of designed joint to changes in temperature are described. Illustrations of conventional gimbal joint and improved gimbal joint are provided.

  9. 14 CFR 29.935 - Shafting joints.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...ROTORCRAFT Powerplant Rotor Drive System § 29.935 Shafting joints. Each universal joint, slip joint, and other shafting joints whose lubrication is necessary for operation must have provision for...

  10. 14 CFR 29.935 - Shafting joints.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...ROTORCRAFT Powerplant Rotor Drive System § 29.935 Shafting joints. Each universal joint, slip joint, and other shafting joints whose lubrication is necessary for operation must have provision for...

  11. 14 CFR 29.935 - Shafting joints.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...ROTORCRAFT Powerplant Rotor Drive System § 29.935 Shafting joints. Each universal joint, slip joint, and other shafting joints whose lubrication is necessary for operation must have provision for...

  12. 14 CFR 27.935 - Shafting joints.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...ROTORCRAFT Powerplant Rotor Drive System § 27.935 Shafting joints. Each universal joint, slip joint, and other shafting joints whose lubrication is necessary for operation must have provision for...

  13. 14 CFR 27.935 - Shafting joints.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...ROTORCRAFT Powerplant Rotor Drive System § 27.935 Shafting joints. Each universal joint, slip joint, and other shafting joints whose lubrication is necessary for operation must have provision for...

  14. 14 CFR 29.935 - Shafting joints.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...ROTORCRAFT Powerplant Rotor Drive System § 29.935 Shafting joints. Each universal joint, slip joint, and other shafting joints whose lubrication is necessary for operation must have provision for...

  15. 14 CFR 29.935 - Shafting joints.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...ROTORCRAFT Powerplant Rotor Drive System § 29.935 Shafting joints. Each universal joint, slip joint, and other shafting joints whose lubrication is necessary for operation must have provision for...

  16. 14 CFR 27.935 - Shafting joints.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...ROTORCRAFT Powerplant Rotor Drive System § 27.935 Shafting joints. Each universal joint, slip joint, and other shafting joints whose lubrication is necessary for operation must have provision for...

  17. 14 CFR 27.935 - Shafting joints.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...ROTORCRAFT Powerplant Rotor Drive System § 27.935 Shafting joints. Each universal joint, slip joint, and other shafting joints whose lubrication is necessary for operation must have provision for...

  18. 14 CFR 27.935 - Shafting joints.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...ROTORCRAFT Powerplant Rotor Drive System § 27.935 Shafting joints. Each universal joint, slip joint, and other shafting joints whose lubrication is necessary for operation must have provision for...

  19. Formation of tough composite joints

    SciTech Connect

    Brun, M.K. [GE Corporate Research and Development, Schenectady, NY (United States)

    1997-05-01

    Joints which exhibit tough fracture behavior were formed in a composite with a Si/SiC matrix reinforced with Textron SCS-6 fibers with either boron nitride or silicon nitride fiber coatings. In composites with BN coatings fibers were aligned uniaxially, while composites with Si{sub 3}N{sub 4}-coated fibers had a 0/90{degree} architecture. Lapped joints (joints with overlapping fingers) were necessary to obtain tough behavior. Geometrical requirements necessary to avoid brittle joint failure have been proposed. Joints with a simple overlap geometry (only a few fingers) would have to be very long in order to prevent brittle failure. Typical failure in these joints is caused by a crack propagating along the interfaces between the joint fingers. Joints of the same overall length, but with geometry changed to be symmetric about the joint centerline and with an extra shear surface exhibited tough fractures accompanied with extensive fiber pullout. The initial matrix cracking of these joints was relatively low because cracks propagated easily through the ends of the fingers. Joints with an optimized stepped sawtooth geometry produced composite-like failures with the stress/strain curves containing an elastic region followed by a region of rising stress with an increase of strain. Increasing the fiber/matrix interfacial strength from 9 to 25 MPa, by changing the fiber coating, increased matrix cracking and ultimate strength of the composite significantly. The best joints had matrix cracking stress and ultimate strength of 138 and 240 MPa, respectively. Joint failure was preceded by multiple matrix cracking in the entire composite. The high strength of the joints will permit building of structures containing joints with only a minor reduction of design stresses.

  20. Photoelectrochemical hydrogen generation with linear gradient Al composition dodecagon faceted AlGaN/n-GaN electrode.

    PubMed

    Lai, W C; Ma, M H; Lin, B K; Hsieh, B H; Wu, Y R; Sheu, J K

    2014-12-15

    We demonstrated photoelectrochemical cells (PECs) with dodecagon faceted AlGaN/n-GaN heterostructure electrode for H(2) generation, where the AlGaN/n-GaN heterostructure has a linear gradient Al composition (LGAC). The separation efficiency of the photo-generated electron-hole pairs in the electrode performs a key function in the H(2) generation efficiency of PEC cells. The linear gradient Al composition, AlGaN, could create more internal field and light absorption because of the linear graded band gap. Therefore, the zero-bias photocurrent density of PEC cells with dodecagon facet LGAC AlGaN/n-GaN heterostructure electrode is around 5.9 times larger than that of dodecagon faceted n-GaN electrode. PMID:25607499

  1. Electrochemical degradation of refractory pollutants using TiO2 single crystals exposed by high-energy {001} facets.

    PubMed

    Zhang, Ai-Yong; Long, Lu-Lu; Liu, Chang; Li, Wen-Wei; Yu, Han-Qing

    2014-12-01

    Anodic material plays a vital role in electrochemical water treatment. Titanium dioxide (TiO2) has been widely recognized as an excellent semiconductor photocatalyst, rather than an efficient electrocatalyst, due to its relatively low electric conductivity and poor electrochemical activity. In this work, it is found that TiO2 can actually become a superior electrocatalyst when its crystal shape and exposed facet are finely tuned. The shape-engineered TiO2 single crystals with {001} facets exhibit an excellent electro-catalytic activity and stability for degrading typical organic pollutants such as rhodamine B and bisphenol A, and treating complex landfill leachate. Its electro-catalytic superiority is mainly attributed to the single-crystalline structure and exposed polar {001} facet. Our findings could provide new possibility of utilizing TiO2 for efficient electrochemical water treatment because of its high activity, great stability, low cost and no toxicity. PMID:25222331

  2. A Big Five facet analysis of sub-clinical narcissism: understanding boldness in terms of well-known personality traits.

    PubMed

    Furnham, Adrian; Crump, John

    2014-08-01

    This study aimed to examine a Big Five 'bright-side' analysis of a sub-clinical personality disorder, i.e. narcissism. A total of 6957 British adults completed the NEO-PI-R, which measures the Big Five Personality factors at the domain and the facet level, as well as the Hogan Development Survey (HDS), which has a measure of Narcissism called Bold as one of its dysfunctional interpersonal tendencies. Correlation and regression results confirmed many of the associations between the Big Five domains and facets (NEO-PI-R) and sub-clinical narcissism. The Bold (Narcissism) scale from the HDS was the criterion variable in all analyses. Bold individuals are disagreeable extraverts with very low scores on facet Modesty but moderately high scores on Assertiveness, Competence and Achievement Striving. The study confirmed work using different population groups and different measures. PMID:24733713

  3. Edge-facet pumped, multi-aperture, thin-disk laser geometry for very high average power output scaling

    DOEpatents

    Zapata, Luis E.

    2004-12-21

    The average power output of a laser is scaled, to first order, by increasing the transverse dimension of the gain medium while increasing the thickness of an index matched light guide proportionately. Strategic facets cut at the edges of the laminated gain medium provide a method by which the pump light introduced through edges of the composite structure is trapped and passes through the gain medium repeatedly. Spontaneous emission escapes the laser volume via these facets. A multi-faceted disk geometry with grooves cut into the thickness of the gain medium is optimized to passively reject spontaneous emission generated within the laser material, which would otherwise be trapped and amplified within the high index composite disk. Such geometry allows the useful size of the laser aperture to be increased, enabling the average laser output power to be scaled.

  4. Multi-facet concentrator of solar setup for irradiating the objects placed in a target plane with solar light

    DOEpatents

    Lewandowski, Allan A. (Evergreen, CO); Yampolskiy, Vladislav (Moscow, RU); Alekseev, Valerie (Moscow, RU); Son, Valentin (Moscow, RU)

    2001-01-01

    According to the proposed invention, this technical result is achieved so that many-facet concentrator of a solar setup for exposure of objects, placed in a target plane, to the action of solar radiation containing a supporting frame and facets differing by that the facets of the concentrator are chosen with spherical focusing reflective surfaces of equal focal lengths and with selective coatings reflecting a desired spectral fraction of solar radiation, and are arranged on the supporting frame symmetrically with respect to the common axis of the concentrator, their optical axes being directed to the single point on the optical axis of the concentrator located before the nominal focus point of the concentrator and determining the position of arranging the target plane.

  5. Preliminary bolted-joint data

    NASA Technical Reports Server (NTRS)

    Wichorek, G. R.

    1979-01-01

    Bolted-joint strength and failure modes for advanced graphite/polyimide composite laminates at 116K (-250 F), room temperature, and 589K (600 F) were determined to provide preliminary design data. The bolted-joint test setup for the low and elevated temperature tests is described. Test results are reported on a quasi-isotropic laminate of Celion 6000/PMR-15. Single bolt, double lap shear specimens were tested to obtain maximum joint strength and failure mode. The effect of joint geometry and temperature on joint strength and failure mode is presented.

  6. Prosthetic elbow joint

    NASA Technical Reports Server (NTRS)

    Weddendorf, Bruce C. (inventor)

    1994-01-01

    An artificial, manually positionable elbow joint for use in an upper extremity, above-elbow, prosthetic is described. The prosthesis provides a locking feature that is easily controlled by the wearer. The instant elbow joint is very strong and durable enough to withstand the repeated heavy loadings encountered by a wearer who works in an industrial, construction, farming, or similar environment. The elbow joint of the present invention comprises a turntable, a frame, a forearm, and a locking assembly. The frame generally includes a housing for the locking assembly and two protruding ears. The forearm includes an elongated beam having a cup-shaped cylindrical member at one end and a locking wheel having a plurality of holes along a circular arc on its other end with a central bore for pivotal attachment to the protruding ears of the frame. The locking assembly includes a collar having a central opening with a plurality of internal grooves, a plurality of internal cam members each having a chamfered surface at one end and a V-shaped slot at its other end; an elongated locking pin having a crown wheel with cam surfaces and locking lugs secured thereto; two coiled compression springs; and a flexible filament attached to one end of the elongated locking pin and extending from the locking assembly for extending and retracting the locking pin into the holes in the locking wheel to permit selective adjustment of the forearm relative to the frame. In use, the turntable is affixed to the upper arm part of the prosthetic in the conventional manner, and the cup-shaped cylindrical member on one end of the forearm is affixed to the forearm piece of the prosthetic in the conventional manner. The elbow joint is easily adjusted and locked between maximum flex and extended positions.

  7. Interface structure of faceted lath-shaped Cr precipitates in a Cu-0.33 wt% Cr alloy

    SciTech Connect

    Luo, C.P.; Dahmen, U. [Lawrence Berkeley National Lab., CA (United States). National Center for Electron Microscopy] [Lawrence Berkeley National Lab., CA (United States). National Center for Electron Microscopy

    1998-03-23

    The interface structure of lath-shaped, faceted Cr-rich precipitates in a Cu-0.33 wt% Cr alloy was investigated by transmission electron microscopy using diffraction contrast and weak beam dark field imaging techniques. The lath axis was aligned precisely with the [5{bar 6}1]{sub f} invariant line direction, and its cross-sectional shape was characterized by four distinct facets with different defect contents. The major facet near (335){sub f} appeared defect-free. The (111){sub f} and (552){sub f} facets showed a single set of ledges with a step height of {approximately}1.1 nm and an associated displacement vector along {approximately}[335]{sub f}. The curves {approximately}(44{bar 3}){sub f} side facets contained an array of dislocations spaced {approximately}8.1 nm apart with a Burgers vector that could reasonably be characterized as 1/3[111]{sub f} or 1/2[110]{sub b}, i.e. as d.s.c. lattice dislocations accommodating the misfit in interplanar spacing of the parallel close-packed planes in the two phases. A detailed model of the interface is in excellent agreement with the observed defect structure and the previously determined crystallographic characteristics. The model shows that the major facet near (335){sub f} which appears to be defect free, actually contains a closely spaced array of dislocations in near-screw orientation. The uniform ledge height of {approximately}1.1 nm in all interfaces is the plane spacing of the primary O-lattice planes of Zhang and Purdy.

  8. Application of combined EBSD and 3D-SEM technique on crystallographic facet analysis of steel at low temperature.

    PubMed

    Mohseni, P; Solberg, J K; Karlsen, M; Akselsen, O M; Ostby, E

    2013-07-01

    Electron backscatter diffraction has been increasingly used to identify the crystallographic planes and orientation of cleavage facets with respect to the rolling direction in fracture surfaces. The crystallographic indices of cleavage planes can be determined either directly from the fracture surface or indirectly from metallographic sections perpendicular to the plane of the fracture surface. A combination of electron backscatter diffraction and 3D scanning electron microscopy imaging technique has been modified to determine crystallographic facet orientations. The main purpose of this work has been to identify the macroscopic crystallographic orientations of cleavage facets in the fracture surfaces of weld heat affected zones in a well-known steel fractured at low temperatures. The material used for the work was an American Petroleum Institute (API) X80 grade steel developed for applications at low temperatures, and typical heat affected zone microstructures were obtained by carrying out weld thermal simulation. The fracture toughness was measured at different temperatures (0°C, -30°C, -60°C and -90°C) by using Crack Tip Opening Displacement testing. Fracture surfaces and changes in microstructure were analyzed by scanning electron microscopy and light microscopy. Crystallographic orientations were identified by electron backscatter diffraction, indirectly from a polished section perpendicular to the major fracture surface of the samples. Computer assisted 3D imaging was used to measure the angles between the cleavage facets and the adjacent polished surface, and then these angles were combined with electron backscatter diffraction measurements to determine the macroscopic crystallographic planes of the facets. The crystallographic indices of the macroscopic cleavage facet planes were identified to be {100}, {110}, {211} and {310} at all temperatures. PMID:23692572

  9. Association of NEO personality domains and facets with presence, onset, and treatment outcomes of major depression in older adults

    PubMed Central

    Hayward, R. David; Taylor, Warren D.; Smoski, Moria J.; Steffens, David C.; Payne, Martha E.

    2012-01-01

    Objectives To assess the relationship of multiple domains and facets of the five factor model of personality with presence, onset, and severity of late life depression. Design Cross-sectional analysis of depression status, and age of onset. Retrospective analysis of baseline severity. Longitudinal analysis of severity after 3 and 12 months of psychiatric treatment. Setting: Private university-affiliated medical center in the Southeastern US. Participants One hundred twelve psychiatric patients with a current episode of unipolar major depression, and 104 nondepressed comparison subjects, ages 60 years and older (mean = 70, SD = 6). Measurements Revised NEO Personality Inventory, Diagnostic Interview Schedule, Montgomery-Åsberg Depression Rating Scale. Results Binary logistic regression found that depression was related to higher neuroticism (and all its facets), and to lower extraversion (and facets of assertiveness, activity, and positive emotionality), and conscientiousness (and facets of competence, order, dutifulness, and self-discipline). Multinomial logistic regression found some of these relationships held only for depression with onset before age 50 (hostility, self-consciousness, extraversion, assertiveness, positive emotions, order, and dutifulness). Linear regression found that personality was unrelated to depression severity at the beginning of treatment, but improvement after 3 months was related to lower neuroticism (and facets depressiveness and stress-vulnerability) and higher warmth and competence. Improvement after 12 months was related to lower neuroticism, depressiveness, and stress-vulnerability. Conclusions Specific personality facets are related with depression and treatment outcomes. Screening for certain personality traits at the start of treatment may help identify patients at risk of worse response to treatment after 3 months. PMID:23290206

  10. Formation of tough composite joints

    SciTech Connect

    Brun, M.K. [GE Corporate Research and Development, Schenectady, NY (United States)

    1998-12-01

    Joints that exhibited tough fracture behavior were formed in a Si/SiC matrix reinforced with Textron SCS-6 fibers with either boron nitride or silicon nitride fiber coatings. Lapped joints (joints with overlapping fingers) were necessary to obtain tough behavior. Geometrical requirements necessary to avoid brittle joint failure were proposed. Joints with a simple overlap geometry (only a few fingers) had to be very long in order to prevent brittle failure. Joints with an optimized stepped sawtooth geometry produced composite-like failures with the stress/strain curves containing an elastic region followed by a region of rising stress with an increase of strain. Increasing the fiber/matrix interfacial strength, by changing the fiber coating, significantly increased matrix cracking and ultimate strength of the joints. The best joints had matrix cracking stress and ultimate strength of 138 and 240 MPa, respectively. Joint failure was preceded by multiple matrix cracking in the entire composite. The high strength of the joints should permit building of structures containing joints with only a minor reduction of design stresses.

  11. Postero-Lateral Disc Prosthesis Combined With a Unilateral Facet Replacement Device Maintains Quantity and Quality of Motion at a Single Lumbar Level

    PubMed Central

    Nayak, Aniruddh N.; Doarn, Michael C.; Gaskins, Roger B.; James, Chris R.; Cabezas, Andres F.; Castellvi, Antonio E.

    2014-01-01

    Background Mechanically replacing one or more pain generating articulations in the functional spinal unit (FSU) may be a motion preservation alternative to arthrodesis at the affected level. Baseline biomechanical data elucidating the quantity and quality of motion in such arthroplasty constructs is non-existent. Purpose The purpose of the study was to quantify the motion-preserving effect of a posterior total disc replacement (PDR) combined with a unilateral facet replacement (FR) system at a single lumbar level (L4-L5). We hypothesized that reinforcement of the FSU with unilateral FR to replace the resected, native facet joint following PDR implantation would restore quality and quantity of motion and additionally not change biomechanics at the adjacent levels. Study Design In-vitro study using human cadaveric lumbar spines. Methods Six (n = 6) cadaveric lumbar spines (L1-S1) were evaluated using a pure-moment stability testing protocol (±7.5 Nm) in flexion-extension (F/E), lateral bending (LB) and axial rotation (AR). Each specimen was tested in: (1) intact; (2) unilateral FR; and (3) unilateral FR + PDR conditions. Index and adjacent level ROM (using hybrid protocol) were determined opto-electronically. Interpedicular travel (IPT) and instantaneous center of rotation (ICR) at the index level were radiographically determined for each condition. ROM, ICR, and IPT measurements were compared (repeated measures ANOVA) between the three conditions. Results Compared to the intact spine, no significant changes in F/E, LB or AR ROM were identified as a result of unilateral FR or unilateral FR + PDR. No significant changes in adjacent L3-L4 or L5-S1 ROM were identified in any loading mode. No significant differences in IPT were identified between the three test conditions in F/E, LB or AR at the L4-L5 level. The ICRs qualitatively were similar for the intact and unilateral FR conditions and appeared to follow placement (along the anterior-posterior (AP) direction) of the PDR in the disc space Conclusion Biomechanically, quantity and quality of motion are maintained with combined unilateral FR + PDR at a single lumbar spinal level. PMID:25694929

  12. Ionic liquid-assisted fabrication of copper hydroxyphosphate nanocrystals with exposed {100} facets for enhanced photocatalytic activity

    NASA Astrophysics Data System (ADS)

    Duan, Xiaochuan; Xiao, Songhua; Liu, Yuan; Huang, Hui; Wang, Dandan; Wang, Lingling; Liu, Bin; Wang, Taihong

    2015-01-01

    Libethenite Cu2PO4OH nanocrystals with different morphologies were prepared by an ionic liquid-assisted hydrothermal route, and were further investigated as photocatalysts under visible-light irradiation. The Cu2PO4OH elongated truncated bipyramids exposing {100} facets exhibit superior photocatalytic activity compared to other particles, which can be attributed to the presence of 100% Cu5c atoms on {100} facets. It is highly expect this research can provide a useful fundamental understanding of shape-dependent photocatalytic performance of copper hydroxyphosphate.

  13. Ionic liquid-assisted fabrication of copper hydroxyphosphate nanocrystals with exposed {100} facets for enhanced photocatalytic activity.

    PubMed

    Duan, Xiaochuan; Xiao, Songhua; Liu, Yuan; Huang, Hui; Wang, Dandan; Wang, Lingling; Liu, Bin; Wang, Taihong

    2015-01-21

    Libethenite Cu2PO4OH nanocrystals with different morphologies were prepared by an ionic liquid-assisted hydrothermal route, and were further investigated as photocatalysts under visible-light irradiation. The Cu2PO4OH elongated truncated bipyramids exposing {100} facets exhibit superior photocatalytic activity compared to other particles, which can be attributed to the presence of 100% Cu5c atoms on {100} facets. It is highly expect this research can provide a useful fundamental understanding of shape-dependent photocatalytic performance of copper hydroxyphosphate. PMID:25549152

  14. Design of a Shape Memory Alloy deployment hinge for reflector facets

    NASA Technical Reports Server (NTRS)

    Anders, W. S.; Rogers, C. A.

    1991-01-01

    A design concept for a Shape Memory Alloy (SMA) actuated hinge mechanism for deploying segmented facet-type reflector surfaces on antenna truss structures is presented. The mechanism uses nitinol, a nickel-titanium shape memory alloy, as a displacement-force micro-actuator. An electrical current is used to resistively heat a 'plastically' elongated SMA actuator wire, causing it to contract in response to a thermally-induced phase transformation. The resulting tension creates a moment, imparting rotary motion between two adjacent panels. Mechanical stops are designed into the device to limit its range of motion and to establish positioning accuracy at the termination of deployment. The concept and its operation are discussed in detail, and an analytical dynamic simulation model is presented. The model has been used to perform nondimensionalized parametric design studies.

  15. Preparation and characterization of ultraflat Pt facets by atom-height-resolved differential optical microscopy

    NASA Astrophysics Data System (ADS)

    Azhagurajan, M.; Wen, R.; Kim, Y. G.; Itoh, T.; Sashikata, K.; Itaya, K.

    2015-01-01

    We recently demonstrated that improvements to our technique, laser confocal microscopy with differential interference microscopy (LCM-DIM), has rendered it fully capable of resolving monatomic steps with heights of ca. 0.25 nm on Au(111) and Pd(111) surfaces, even as low as 0.14 nm on Si(100), in aqueous solution. In this paper, we describe in detail a method to prepare and characterize, via atomic-layer-resolved LCM-DIM, ultraflat Pt(111) and Pt(100) facets over a wide surface area. The preparation of ultraflat surfaces is important in the characterization at the atomic scale of electrochemical processes under reaction conditions. To showcase the elegance of LCM-DIM, the anodic dissolution of Pt in aqueous HCl is briefly recounted.

  16. Introducing FACETS, the Framework Application for Core-Edge Transport Simulations

    SciTech Connect

    Cary, John R. [Tech-X Corporation; Candy, Jeff [General Atomics; Cohen, Ronald H. [Lawrence Livermore National Laboratory (LLNL); Krasheninnikov, Sergei I [ORNL; McCune, Douglas C [ORNL; Estep, Donald J [Colorado State University, Fort Collins; Larson, Jay W [ORNL; Malony, Allen [University of Oregon; Worley, Patrick H [ORNL; Carlsson, Johann Anders [ORNL; Hakim, A H [Tech-X Corporation; Hamill, P [Tech-X Corporation; Kruger, Scott E [ORNL; Muzsala, S [Tech-X Corporation; Pletzer, Alexander [ORNL; Shasharina, Svetlana [Tech-X Corporation; Wade-Stein, D [Tech-X Corporation; Wang, N [Tech-X Corporation; McInnes, Lois C [ORNL; Wildey, T [Tech-X Corporation; Casper, T. A. [Lawrence Livermore National Laboratory (LLNL); Diachin, Lori A [ORNL; Epperly, Thomas [Lawrence Livermore National Laboratory (LLNL); Rognlien, T. D. [Lawrence Livermore National Laboratory (LLNL); Fahey, Mark R [ORNL; Kuehn, Jeffery A [ORNL; Morris, A [University of Oregon; Shende, Sameer [University of Oregon; Feibush, E [Tech-X Corporation; Hammett, Gregory W [ORNL; Indireshkumar, K [Tech-X Corporation; Ludescher, C [Tech-X Corporation; Randerson, L [Tech-X Corporation; Stotler, D. [Princeton Plasma Physics Laboratory (PPPL); Pigarov, A [University of California, San Diego; Bonoli, P. [Massachusetts Institute of Technology (MIT); Chang, C S [New York University; D'Ippolito, D. A. [Lodestar Research Corporation; Colella, Philip [Lawrence Berkeley National Laboratory (LBNL); Keyes, David E [Columbia University; Bramley, R [Indiana University; Myra, J. R. [Lodestar Research Corporation

    2007-06-01

    The FACETS (Framework Application for Core-Edge Transport Simulations) project began in January 2007 with the goal of providing core to wall transport modeling of a tokamak fusion reactor. This involves coupling previously separate computations for the core, edge, and wall regions. Such a coupling is primarily through connection regions of lower dimensionality. The project has started developing a component-based coupling framework to bring together models for each of these regions. In the first year, the core model will be a 1 dimensional model (1D transport across flux surfaces coupled to a 2D equilibrium) with fixed equilibrium. The initial edge model will be the fluid model, UEDGE, but inclusion of kinetic models is planned for the out years. The project also has an embedded Scientific Application Partnership that is examining embedding a full-scale turbulence model for obtaining the crosssurface fluxes into a core transport code.

  17. Local supersaturation dictated branching and faceting of submicrometer PbS particles with cubic growth habit.

    PubMed

    Liu, Mingzhu; Leng, Mei; Liu, Dan; Chen, Fanglin; Li, Chengyu; Wang, Cheng

    2014-11-01

    Hierarchical cubelike submicrometer PbS particles consisting of truncated octahedrons, cuboctahedrons, and cubes were prepared in ethylene glycol solution under favorable high mole ratio of thiourea (Tu) to Pb(AC)2 (R(S/Pb)) via a pumping process. A qualitative analysis based on the classical nucleation theory coupled with the crystal growth theory is employed to interpret the observed experimental phenomena. By varying the concentration of reactants, R(S/Pb), and reaction temperature, it is possible to tune the local supersaturation degree (LSD), which is determined by the number of nuclei and overall growth unit (or concentration), surrounding each growing particle that dictates the branching and faceting of PbS particle. Relatively high LSD that is required for branching growth could be achieved at lower concentration of Tu and reaction temperature. Increasing the concentration of Tu and reaction temperature resulted in less LSD and yielded cubic PbS particles. PMID:25338760

  18. Estimating Facets of Psychopathy From Normal Personality Traits: A Step Toward Community Epidemiological Investigations

    PubMed Central

    Benning, Stephen D.; Patrick, Christopher J.; Blonigen, Daniel M.; Hicks, Brian M.; Iacono, William G.

    2008-01-01

    In three samples consisting of community and undergraduate men and women and incarcerated men, we examined the criterion validity of two distinct factors of psychopathy embodied in the Psychopathic Personality Inventory (PPI) as indexed by primary trait scales from the Multidimensional Personality Questionnaire (MPQ). Consistent with the PPI factors themselves, MPQ-estimated PPI-I related negatively with internalizing disorder symptoms and fearfulness and positively with thrill and adventure seeking, sociability, activity, and narcissism. MPQ-estimated PPI-II was associated negatively with socialization and positively with externalizing disorder symptoms, impulsivity, disinhibition and boredom susceptibility, and trait anxiety and negative emotionality. Additionally, PPI-I was selectively related to the interpersonal facet of Factor 1 of the Psychopathy Checklist—Revised (PCL-R), whereas PPI-II was related preferentially to Factor 2 of the PCL-R. PMID:15695739

  19. Co3O4 nanocages with highly exposed {110} facets for high-performance lithium storage

    PubMed Central

    Liu, Dequan; Wang, Xi; Wang, Xuebin; Tian, Wei; Bando, Yoshio; Golberg, Dmitri

    2013-01-01

    Functional materials with both exposed highly reactive planes and hollow structures have attracted considerable attentions with respect to improved catalytic activity and enhanced electrochemical energy storage. Herein, we report the synthesis of unusual single-crystal Co3O4 nanocages with highly exposed {110} reactive facets via a one-step solution method. When tested as anode materials in lithium-ion batteries, these Co3O4 nanocages deliver a high reversible lithium storage capacity of 864?mAh g?1 at 0.2C over 50 cycles and exhibit an excellent rate capability. The dominantly exposed {110} planes, a high density of atomic steps in nanocages, and the large void interiors lead to the regarded superior electrochemical performance. PMID:23995848

  20. Fat facets deubiquitylation of Medea/Smad4 modulates interpretation of a Dpp morphogen gradient.

    PubMed

    Stinchfield, Michael J; Takaesu, Norma T; Quijano, Janine C; Castillo, Ashley M; Tiusanen, Nina; Shimmi, Osamu; Enzo, Elena; Dupont, Sirio; Piccolo, Stefano; Newfeld, Stuart J

    2012-08-01

    The ability of secreted Transforming Growth Factor ? (TGF?) proteins to act as morphogens dictates that their influence be strictly regulated. Here, we report that maternally contributed fat facets (faf; a homolog of USP9X/FAM) is essential for proper interpretation of the zygotic Decapentaplegic (Dpp) morphogen gradient that patterns the embryonic dorsal-ventral axis. The data suggest that the loss of faf reduces the activity of Medea (a homolog of Smad4) below the minimum necessary for adequate Dpp signaling and that this is likely due to excessive ubiquitylation on a specific lysine. This study supports the hypothesis that the control of cellular responsiveness to TGF? signals at the level of Smad4 ubiquitylation is a conserved mechanism required for proper implementation of a morphogen gradient. PMID:22745309

  1. The size and diffusion effect of gold on silicon nanowire sidewall faceting

    NASA Astrophysics Data System (ADS)

    Seo, Deok-Won; Kim, Gil-Sung; Lee, Chan-Yang; Lee, Seung-Yong; Hyung, Jung-Hwan; Choi, Chel-Jong; Lee, Sang-Kwon

    2012-02-01

    Single crystalline silicon nanowires (SiNWs) were grown using a gold (Au)-catalyzed vapor-liquid-solid (VLS) approach. In this study, we examine the influence of the size of Au catalyst droplets on the size of SiNWs and discuss the effect of Au diffusion and surface passivation on SiNW sidewall faceting and roughening in the VLS process. To simultaneously cover a variety of sizes of SiNWs on the same substrate, 2-nm-thick Au film was used on Si (111) substrate as a catalyst, since it is known that Au thin film-based seed offers relatively less control of the NW size, due to the randomness of the film breakup at reaction temperature. We then found that the grown SiNWs have two main types of surface morphologies on the sidewall of the nanowires (NWs). One type had a small and coarse surface morphology with no Au-Si droplets at the top of the NWs. The other type had a long and smooth surface and still had Au-Si droplets at the end. The fact that resulting SiNWs have two main different surface morphologies can be explained by three reasons: the size difference of Au-Si droplets, Au diffusion to the surface of the SiNWs, and surface passivation on the SiNW surface. Furthermore, we proposed a combined VLS and vapor-solid (VS) growth model to describe the creation of the facets and roughening of the sidewall of the NWs. Our results point toward the exciting possibility that the proposed well-controlled and coarse-surfaced SiNWs could be promising thermoelectric materials with low thermal conductivity, since the thermal conductivity is greatly reduced at the rough surface due to the enhancement of phonon scattering.

  2. Angular and spectral sensitivity of fly photoreceptors. I. Integrated facet lens and rhabdomere optics.

    PubMed

    Stavenga, D G

    2003-01-01

    Three optical components of a fly's eye determine the angular sensitivity of the photoreceptors: the light diffracting facet lens, the wave-guiding rhabdomere and the light-absorbing visual pigment in the rhabdomere. How the integrated optical system of the fly eye shapes the angular sensitivity curves is quantitatively analyzed in five steps: (1) scalar diffraction theory for low Fresnel-number lenses is applied to four different facet lenses, with diameter 10, 20, 40, and 80 micro m, respectively, assuming a constant F-number of 2.2; (2) optical waveguide theory is used to calculate waveguide modes propagating in circular cylindrical rhabdomeres with diameter 1.0, 2.0, and 4.0 micro m, respectively; (3) the excitation of waveguide modes is studied with the tip of the waveguide positioned in the focal plane as well as outside this plane; (4) the light absorption from the various propagated modes by the visual pigment in the rhabdomere is calculated as a function of the angle of the incident light wave; and (5) the angular sensitivity of the photoreceptor is obtained by normalizing the total light absorption. Four wavelengths are considered: 300, 400, 500 and 600 nm. The analysis shows that the wavelength dependency of the lens diffraction is strongly compensated by that of the waveguide modes, an effect which is further enhanced by the decrease in light absorption when the mode number increases. The angular sensitivity of fly photoreceptors is robust to defocus and largely wavelength independent for all except very slender rhabdomeres. PMID:12548425

  3. Proceedings of 2011 NSF Engineering Research and Innovation Conference, Atlanta, Georgia Grant #0856206 Automatic 3D Facet Orientations Estimation from LIDAR Imaging

    E-print Network

    Maerz, Norbert H.

    #0856206 Automatic 3D Facet Orientations Estimation from LIDAR Imaging Ye Duan, Xiaoling Li University: This paper presents our current research progress on automatic 3D facet orientations estimation from LIDAR to generate the main fracture surfaces orientations from LIDAR data. Our algorithm/software has been tested

  4. Temporomandibular Joint Disorders

    NSDL National Science Digital Library

    Patient Education Institute

    This patient education program explains temporomandibular joint disorders (TMJ). It reviews the anatomy of the jaw, plus symptoms, causes, diagnosis, and treatment options for TMJ disorders. This resource is a MedlinePlus Interactive Health Tutorial from the National Library of Medicine, designed and developed by the Patient Education Institute. NOTE: This tutorial requires a special Flash plug-in, version 4 or above. If you do not have Flash, you will be prompted to obtain a free download of the software before you start the tutorial. You will also need an Acrobat Reader, available as a free download, in order to view the Reference Summary.

  5. Bladder operated robotic joint

    NASA Technical Reports Server (NTRS)

    Robertson, Glen A. (inventor)

    1993-01-01

    This invention is a robotic joint which is operated by inflatable bladders and which can be used in applications where it is desired to move or hold an object. A support block supports an elongated plate to which is pivotally attached a finger. A tension strip passes over a lever attached to the finger and is attached at its ends to the support block on opposite sides of the plate. Bladders positioned between the plate and the tension strip on opposite sides of the plate can be inflated by pumps to pivot the finger, with one of the bladders being inflated while the other is being deflated.

  6. Construction of an Attitude Behavior Scale of Blacks and Whites Toward Each Using Guttman Facet Design and Analysis.

    ERIC Educational Resources Information Center

    Hamersma, Richard J.

    This paper deals with a scale of attitudes of whites towards blacks and blacks towards whites, constructed using Guttmann's methods of facet analysis. The source of the scale was the finding by the National Advisory Commission on Civil Disorders and other researchers that there was a consistent hierarchy of grievances in every major city surveyed.…

  7. Faceted growth of primary Al{sub 2}Cu crystals during directional solidification in high magnetic field

    SciTech Connect

    Li, Chuanjun; Ren, Zhongming; Shen, Yu [School of Materials Science and Engineering, Shanghai University, Shanghai 200072 (China)] [School of Materials Science and Engineering, Shanghai University, Shanghai 200072 (China); Wang, Qiuliang; Dai, Yinming; Wang, Hui [Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190 (China)] [Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190 (China)

    2013-10-21

    The high magnetic field is widely used to modify the crystal morphology. In this work, the effect of the magnetic field on growing behavior of faceted crystals in the Al-40 wt. %Cu alloy was investigated using directional solidification technique. It was found that the faceted growth of primary Al{sub 2}Cu phase was degraded and the primary spacing was reduced upon applying the magnetic field. Additionally, the length of the mushy zone first decreased and then increased with increase of the magnetic field intensity. The quantitative analysis reveals that the shear stress induced by the fluid motion is insufficient to break the atom bonds at the solid-liquid interface. However, both of the thermoelectric magnetic convection (TEMC) and the thermoelectric magnetic force (TEMF) cause dendrites to fracture and reduce the primary spacing. The two effects also weaken the faceting growth. Moreover, the instability of the solid-liquid interface is generated by the TEMF, which further leads to degrade the faceted growth. The length of mushy zone was changed by the TEMC and reached the minimum in the magnetic field of 0.5 T, which is in good agreement with the predicted value (0.83 T)

  8. Faceting and coarsening dynamics in the complex Swift-Hohenberg equation Lendert Gelens1,* and Edgar Knobloch2

    E-print Network

    Knobloch, Edgar

    coarsen indefinitely, as described by a Cahn-Hilliard equation, or the coarsening ceases leadingFaceting and coarsening dynamics in the complex Swift-Hohenberg equation Lendert Gelens1 94720, USA Received 20 July 2009; published 30 October 2009 The complex Swift-Hohenberg equation models

  9. Sustainable molecular oxygen activation with oxygen vacancies on the {001} facets of BiOCl nanosheets under solar light

    NASA Astrophysics Data System (ADS)

    Li, Hao; Shi, Jingu; Zhao, Kun; Zhang, Lizhi

    2014-11-01

    We demonstrate that oxygen vacancies on the {001} facets of BiOCl nanosheets can more sustainably activate molecular oxygen for organic pollutant removal under solar light than the TiO2 counterparts. The oxygen vacancies on the {001} facets of BiOCl nanosheets are effectively refreshed by UV light, and are also responsible for the efficient utilization of visible light to activate molecular oxygen, accounting for their long term stability and high efficiency.We demonstrate that oxygen vacancies on the {001} facets of BiOCl nanosheets can more sustainably activate molecular oxygen for organic pollutant removal under solar light than the TiO2 counterparts. The oxygen vacancies on the {001} facets of BiOCl nanosheets are effectively refreshed by UV light, and are also responsible for the efficient utilization of visible light to activate molecular oxygen, accounting for their long term stability and high efficiency. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr04810e

  10. The Structural Validity of the Perceived Traits of the "Ideal Student" Multi-Faceted Theory among Education Students

    ERIC Educational Resources Information Center

    Maslovaty, Nava; Cohen, Arie; Furman, Sari

    2008-01-01

    The article presents a multi-faceted theory of "ideal high school student" traits. The trait system, as defined by several theories, is a translation of the teachers' belief system into educational objectives. The study focused on Bloom's taxonomies and the structural validity of its principles, using Similarity Structure Analysis. Aware of the…

  11. Psychometric Properties of the Five Facet Mindfulness Questionnaire in Depressed Adults and Development of a Short Form

    ERIC Educational Resources Information Center

    Bohlmeijer, Ernst; ten Klooster, Peter M.; Fledderus, Martine; Veehof, Martine; Baer, Ruth

    2011-01-01

    In recent years, there has been a growing interest in therapies that include the learning of mindfulness skills. The 39-item Five Facet Mindfulness Questionnaire (FFMQ) has been developed as a reliable and valid comprehensive instrument for assessing different aspects of mindfulness in community and student samples. In this study, the psychometric…

  12. Journal of Crystal Growth 230 (2001) 554557 Characterization of etched facets for GaN-based lasers

    E-print Network

    N (wurtzite structure) is partly accommodated by a 308 rotation of the GaN unit cell relative to the sapphire etching and on the characterization of the etched facets. *Corresponding author. Tel.: +49-731-502-6050; fax: +49- 731-502-6049. E-mail address: marcus.scherer@e-technik.uni-ulm.de (M. Scherer). 0022

  13. Applying the Many-Facet Rasch Model to Evaluate PowerPoint Presentation Performance in Higher Education

    ERIC Educational Resources Information Center

    Basturk, Ramazan

    2008-01-01

    This study investigated the usefulness of the many-facet Rasch model (MFRM) in evaluating the quality of performance related to PowerPoint presentations in higher education. The Rasch Model utilizes item response theory stating that the probability of a correct response to a test item/task depends largely on a single parameter, the ability of the…

  14. Facets of Job Effort in Bus Driver Health: Deconstructing Effort in the Effort–Reward Imbalance Model

    Microsoft Academic Search

    John L. M. Tse; Rhona Flin; Kathryn Mearns

    2007-01-01

    This research aimed to test the relative value of developing and using job-specific facets of effort and testing them using J. Siegrist's (1996) effort–reward imbalance (ERI) theory to extend understanding of how one might determine job strain in urban bus driving. In addition, the interactive effects of the ERI model are further investigated to address the lack of research into

  15. Recognition of Building Roof Facets by Merging Aerial Images and 3D Lidar Data in a Hierarchical Segmentation Framework

    Microsoft Academic Search

    Frédéric Bretar; Marc Pierrot Deseilligny; Michel Roux

    2006-01-01

    We investigate in this paper an original methodology for detecting roof facets through the fusion of aerial images and lidar data (3D point cloud). Based on a hierarchical segmentation of the image, we define a cost function that manages the merging order of regions. It depends on both radio-metric similarities of two neighbouring regions as well as on extracted information

  16. Heterogeneous inhibition processes involved in different facets of self-reported impulsivity: Evidence from a community sample

    Microsoft Academic Search

    Philippe Gay; Lucien Rochat; Joël Billieux; Mathieu d’Acremont; Martial Van der Linden

    2008-01-01

    Whiteside and Lynam (Whiteside, S. P., & Lynam, D. R. (2001). The Five Factor Model and impulsivity: Using a structural model of personality to understand impulsivity. Personality and Individual Differences, 30, 669–689) clarified the multifaceted nature of impulsivity by identifying four distinct facets of self-reported impulsive behaviors: urgency, (lack of) premeditation, (lack of) perseverance, and sensation seeking. Building on work

  17. Job Satisfaction of Female and Male Superintendents: The Influence of Job Facets and Contextual Variables as Potential Predictors

    ERIC Educational Resources Information Center

    Young, I. Phillip; Kowalski, Theodore J.; McCord, Robert S.; Petersen, George J.

    2012-01-01

    A descriptive multiple regression approach was used to assess the job satisfaction of female and male public school superintendents taking part in a decennial survey conducted by AASA. Self-reported job satisfaction of public school superintendents was regressed on their affective reactions to specific job facets (supervision, co-workers, and…

  18. ZnO twin-spheres exposed in ±(001) facets: stepwise self-assembly growth and anisotropic blue emission.

    PubMed

    Li, Feng; Gong, Feilong; Xiao, Yuanhua; Zhang, Aiqin; Zhao, Jihong; Fang, Shaoming; Jia, Dianzeng

    2013-12-23

    ZnO twin-spheres topologically exposed in ±(001) polar facets have been successfully produced on a large scale. The fragmentary and hexagonal ±(001) facets of ZnO tilt and assemble gradually for 8-12 generations to form supercrystals. The surfactant effect on the formation of ZnO supercrystals reveals that their structure stepwise evolves from prisms to dumbbells to twin-spheres exposed in ±(001) facets and eventually to twin-spheres covered with dots. A hollow ring around a prism, which connects two hemispheres of the supercrystals, is finally sealed inside each of the twin-spheres. Based on the experimental observations, a stepwise self-assembly mechanism is proposed to understand the formation of the supercrystals. It is also observed that the ZnO twin-spheres exhibit anisotropic blue emission in intensity attributed to their special surfaces exposed in ±(001) facets. Novel devices could be designed and fabricated through carefully tailoring the microstructure of ZnO supercrystals. PMID:24251905

  19. Essential facets of competence that enable trust in medical graduates: a ranking study among physician educators in two countries.

    PubMed

    Wijnen-Meijer, Marjo; van der Schaaf, Marieke; Nillesen, Kirstin; Harendza, Sigrid; Ten Cate, Olle

    2013-11-01

    One way to operationalize the assessment of trainees in a competency-based context is to determine whether they can be entrusted with critical activities. To determine which facets of competence (FOCs) are most informative for such decisions, we performed a Delphi study among Dutch educators. In the current study, the resulting list of facets of competence was evaluated among experienced Dutch and German clinical educators to determine which facets appear most relevant and to evaluate the agreement among experts in different countries as a support for their external validity. Eight Dutch and eight German experts scored each FOC on a five-point scale for relevance. A rank-order comparison showed that there was almost full agreement about the top 10 FOCs, among which 'Scientific and empirical grounded method of working', 'Knowing and maintaining own personal bounds and possibilities', 'Active professional development', 'Teamwork and collegiality', 'Active listening to patients', and 'Verbal communication with colleagues and supervisors'. We conclude that these facets of competence may be used in a training for educators who need to make entrustment decisions about trainees. PMID:24142879

  20. Green synthesis of anatase TiO(2) nanocrystals with diverse shapes and their exposed facets-dependent photoredox activity.

    PubMed

    Roy, Nitish; Park, Yohan; Sohn, Youngku; Leung, Kam Tong; Pradhan, Debabrata

    2014-10-01

    The exposed facets of a crystal are known to be one of the key factors to its physical, chemical and electronic properties. Herein, we demonstrate the role of amines on the controlled synthesis of TiO2 nanocrystals (NCs) with diverse shapes and different exposed facets. The chemical, physical and electronic properties of the as-synthesized TiO2 NCs were evaluated and their photoredox activity was tested. It was found that the intrinsic photoredox activity of TiO2 NCs can be enhanced by controlling the chemical environment of the surface, i.e.; through morphology evolution. In particular, the rod shape TiO2 NCs with ?25% of {101} and ?75% of {100}/{010} exposed facets show 3.7 and 3.1 times higher photocatalytic activity than that of commercial Degussa P25 TiO2 toward the degradation of methyl orange and methylene blue, respectively. The higher activity of the rod shape TiO2 NCs is ascribed to the facetsphilic nature of the photogenerated carriers within the NCs. The photocatalytic activity of TiO2 NCs are found to be in the order of {101}+{100}/{010} (nanorods) > {101}+{001}+{100}/{010} (nanocuboids and nanocapsules) > {101} (nanoellipsoids) > {001} (nanosheets) providing the direct evidence of exposed facets-depended photocatalytic activity. PMID:25188808

  1. Metal to ceramic sealed joint

    DOEpatents

    Lasecki, J.V.; Novak, R.F.; McBride, J.R.

    1991-08-27

    A metal to ceramic sealed joint which can withstand wide variations in temperature and maintain a good seal is provided for use in a device adapted to withstand thermal cycling from about 20 to about 1000 degrees C. The sealed joint includes a metal member, a ceramic member having an end portion, and an active metal braze forming a joint to seal the metal member to the ceramic member. The joint is positioned remote from the end portion of the ceramic member to avoid stresses at the ends or edges of the ceramic member. The sealed joint is particularly suited for use to form sealed metal to ceramic joints in a thermoelectric generator such as a sodium heat engine where a solid ceramic electrolyte is joined to metal parts in the system. 11 figures.

  2. Strength of Welded Aircraft Joints

    NASA Technical Reports Server (NTRS)

    Brueggeman, W C

    1937-01-01

    This investigation is a continuation of work started in 1928 and described in NACA-TR-348 which shows that the insertion of gusset plates was the most satisfactory way of strengthening a joint. Additional tests of the present series show that joints of this type could be improved by cutting out the portion of the plate between the intersecting tubes. T and lattice joints in thin-walled tubing 1 1/2 by 0.020 inch have somewhat lower strengths than joints in tubing of greater wall thickness because of failure by local buckling. In welding the thin-walled tubing, the recently developed "carburizing flux" process was found to be the only method capable of producing joints free from cracks. The "magnetic powder" inspection was used to detect cracks in the joints and flaws in the tubing.

  3. Proximal interphalangeal joint sprains.

    PubMed

    Wray, R C; Young, V L; Holtman, B

    1984-07-01

    We report the first series of proximal interphalangeal joint sprains and reviewed 50 sprains in 48 patients. The majority of patients were males injured at work. The radial collateral ligament was injured about twice as often as the ulnar ligaments. The little finger was injured significantly less than the others. Proximal interphalangeal joint sprains can be diagnosed by the following: pain localized to the injured ligament, swelling greatest at the site of the injured ligament, tenderness greatest at the site of the injured ligament, pain at the site of the injured ligament during lateral stress, and/or mild lateral instability on radiographs or physical examination during stress testing. All patients required several different splints for treatment; in decreasing frequency, we used immobilizing, coupling, dynamic proximal interphalangeal flexion, dynamic proximal interphalangeal and distal interphalangeal flexion, and dynamic proximal interphalangeal extension splints. The mean active range of motion before treatment was 70 degrees and after treatment was 95 degrees. Significantly more patients had loss of full extension than had loss of full flexion. Forty-six percent of the patients had no pain after treatment, 46 percent had mild pain, 8 percent had moderate pain, and none had severe pain. Patients treated within 4 weeks of their injury (group 1) gained significantly greater range of motion (35 degrees) than those treated between 5 and 14 weeks after their injury (10 degrees) (group 2).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:6739583

  4. Jointly Sponsored Research Program

    SciTech Connect

    Everett A. Sondreal; John G. Hendrikson; Thomas A. Erickson

    2009-03-31

    U.S. Department of Energy (DOE) Cooperative Agreement DE-FC26-98FT40321 funded through the Office of Fossil Energy and administered at the National Energy Technology Laboratory (NETL) supported the performance of a Jointly Sponsored Research Program (JSRP) at the Energy & Environmental Research Center (EERC) with a minimum 50% nonfederal cost share to assist industry in commercializing and effectively applying highly efficient, nonpolluting energy systems that meet the nation's requirements for clean fuels, chemicals, and electricity in the 21st century. The EERC in partnership with its nonfederal partners jointly performed 131 JSRP projects for which the total DOE cost share was $22,716,634 (38%) and the nonfederal share was $36,776,573 (62%). Summaries of these projects are presented in this report for six program areas: (1) resource characterization and waste management, (2) air quality assessment and control, (3) advanced power systems, (4) advanced fuel forms, (5) value-added coproducts, and (6) advanced materials. The work performed under this agreement addressed DOE goals for reductions in CO{sub 2} emissions through efficiency, capture, and sequestration; near-zero emissions from highly efficient coal-fired power plants; environmental control capabilities for SO{sub 2}, NO{sub x}, fine respirable particulate (PM{sub 2.5}), and mercury; alternative transportation fuels including liquid synfuels and hydrogen; and synergistic integration of fossil and renewable resources.

  5. Within-Trait Heterogeneity in Age Group Differences in Personality Domains and Facets: Implications for the Development and Coherence of Personality Traits

    PubMed Central

    Mõttus, René; Realo, Anu; Allik, Jüri; Esko, Tõnu; Metspalu, Andres; Johnson, Wendy

    2015-01-01

    The study investigated differences in the Five-Factor Model (FFM) domains and facets across adulthood. The main questions were whether personality scales reflected coherent units of trait development and thereby coherent personality traits more generally. These questions were addressed by testing if the components of the trait scales (items for facet scales and facets for domain scales) showed consistent age group differences. For this, measurement invariance (MI) framework was used. In a sample of 2,711 Estonians who had completed the NEO Personality Inventory 3 (NEO PI-3), more than half of the facet scales and one domain scale did not meet the criterion for weak MI (factor loading equality) across 12 age groups spanning ages from 18 to 91 years. Furthermore, none of the facet and domain scales met the criterion for strong MI (intercept equality), suggesting that items of the same facets and facets of the same domains varied in age group differences. When items were residualized for their respective facets, 46% of them had significant (p < 0.0002) residual age-correlations. When facets were residualized for their domain scores, a majority had significant (p < 0.002) residual age-correlations. For each domain, a series of latent factors were specified using random quarters of their items: scores of such latent factors varied notably (within domains) in correlations with age. We argue that manifestations of aetiologically coherent traits should show similar age group differences. Given this, the FFM domains and facets as embodied in the NEO PI-3 do not reflect aetiologically coherent traits. PMID:25751273

  6. Disorders of the sacroiliac joint.

    PubMed

    Sizer, Phillip S; Phelps, Valerie; Thompsen, Kirk

    2002-03-01

    Controversies have surrounded the sacroiliac joint. The sacroiliac joint (SIJ) is a considerably complex and strong joint with limited mobility, mechanically serving as a force transducer and a shock absorber. Anatomical changes are seen in the SIJ throughout an individual's lifetime. The ligamentous system associated with the SIJ serves to enhance stability and offer proprioceptive feedback in context with the rich plexus of articular receptors. Stability in the SIJ is related to form and force closure. Movement in the SIJ is 3-D about an axis outside of the joint. The functional examination of the SIJ is related to a clinical triad. PMID:17134467

  7. Early Developments in Joint Action

    PubMed Central

    Brownell, Celia A.

    2012-01-01

    Joint action, critical to human social interaction and communication, has garnered increasing scholarly attention in many areas of inquiry, yet its development remains little explored. This paper reviews research on the growth of joint action over the first 2 years of life to show how children become progressively more able to engage deliberately, autonomously, and flexibly in joint action with adults and peers. It is suggested that a key mechanism underlying the dramatic changes in joint action over the second year of life is the ability to reflect consciously on oneself and one’s behavior and volition and correspondingly, on the behavior, goals, and intentions of others. PMID:23087769

  8. [Anatomic and radiographic examination of the shoulder joint of the cheetah (Acinonyx jubatus)].

    PubMed

    Künzel, W; Probst, A; Henninger, W

    1998-04-01

    Anatomical structures of shoulder joints of five adult cheetahs were examined by dissection, corrosion casts and radiography. The bones, capsules and auxiliary synovial devices were described, as well as ligaments and adjacent muscles. The cheetah shoulder has many similarities with the shoulder joint of the domestic cat, but also considerable differences. Proper osteological features were the large supraglenoid tubercle, the caudally directed coracoid process and the extension of the articular surface of the scapula to the lateral area of the supraglenoid tubercle. On the proximal end of the humerus the width of the head of humerus, the facet of infraspinatus muscle as a shallow cavity with the insertion of the infraspinatus muscle around it and two raised roughnesses on the proximal end of the tricipital line for the insertions of the lateral glenohumeral ligament and the teres minor muscle were noticeable. The insertion of the joint capsule was mainly on the glenoid labrum, only in part of the articular surface on the lateral area of the supraglenoid tubercle laterally on the scapula. The joint capsule formed a supra- and infraspinatus recess laterally, an intertubercular tendon sheet for the biceps brachii muscle cranially, and a bipartited subscapular recess medially. An extracapsular transverse ligament passing the intertubercular groove, a laterally capsular strengthening--called lateral glenohumeral ligament--and an intracapsular medial glenohumeral ligament could be found. The latter one was joined to the capsule by a mesoligament, dividing the subscapular recess into two pouches. PMID:9591374

  9. VOLUME 85, NUMBER 12 P H Y S I C A L R E V I E W L E T T E R S 18 SEPTEMBER 2000 Shocks and Curvature Dynamics: A Test of Global Kinetic Faceting in Crystals

    E-print Network

    Wettlaufer, John S.

    faceting. PACS numbers: 81.10.Aj, 81.30.Fb, 82.65.Dp The study and manipulation of crystallization forms motivates the present study. The qualitative picture of the growth of partially faceted crystals has a rich

  10. Smart material joint band

    NASA Astrophysics Data System (ADS)

    Tucchio, Michael A.; Stoodt, Robert A.; Livsey, Robert A.

    1994-11-01

    The present invention relates to an improved connector for joining two tubular members together. The connector is formed by a plurality of longitudinally extending fingers extending from an end of one of tubular members and at least one locking groove in the other of the tubular members for receiving the fingers. The connector further includes a circumferentially extending wire member which is received in a notch in a head portion of each of the plurality of fingers. The wire member is preferably formed from a shape memory alloy and has an original circumference less than the circumference of a circle formed by the notches in a head portions of the fingers. The connector includes apertures through which electric wires may be connected to the shape memory alloy ring member so as to cause the shape memory alloy ring member to return to its original shape and allow release of the joint connection.

  11. Smart material joint band

    NASA Astrophysics Data System (ADS)

    Tucchio, Michael A.; Stoodt, Robert A.; Livsey, Robert A.

    1993-12-01

    The present invention relates to an improved connector for joining two tubular members together. The connector is formed by a plurality of longitudinally extending fingers extending from an end of one of the tubular members and at least one locking groove in the other of the tubular members for receiving the fingers. The connector further includes a circumferentially extending wire member which is received in a notch in a head portion of each of the plurality of fingers. The wire member is preferably formed from a shape memory alloy and has an original circumference less than the circumference of a circle formed by the notches in the head portions of the fingers. The connector includes apertures through which electric wires may be connected to the shape memory alloy ring member so as to cause the shape memory alloy ring member to return to its original shape and allow release of the joint connection.

  12. Passive Ball Capture Joint

    NASA Technical Reports Server (NTRS)

    Cloyd, Richard A. (Inventor); Bryan, Thomas C. (Inventor)

    2003-01-01

    A passive ball capture joint has a sleeve with a plurality of bores distributed about a circumference thereof and formed therethrough at an acute angle relative to the sleeve's longitudinal axis. A spring-loaded retainer is slidingly fitted in each bore and is biased such that, if allowed, will extend at least partially into the sleeve to retain a ball therein. A ring, rotatably mounted about the bores, has an interior wall defining a plurality of shaped races that bear against the spring-loaded retainers. A mechanized rotational force producer is coupled to the ring. The ring can be rotated from a first position (that presses the retainers into the sleeve to lock the ball in place) to a second position (that allows the retainers to springback out of the sleeve to release the ball).

  13. International Joint Commission

    NSDL National Science Digital Library

    The International Joint Commission was created by Canada and the United States "because they recognized that each country is affected by the other's actions in lake and river systems along the border. The two countries cooperate to manage these waters wisely and to protect them for the benefit of today's citizens and future generations." Visitors to the site can read about great lakes water quality issues, great lakes exports, water levels, news releases, publications, view maps, and much more. One of the latest publications available on the site includes the proceeding from a workshop entitled Addressing Atmospheric Mercury: Science and Policy. This extensive site is well organized and written, giving anyone living near or interested in the great lakes a good source for timely and important information.

  14. Corynebacterium Prosthetic Joint Infection

    PubMed Central

    Cazanave, Charles; Greenwood-Quaintance, Kerryl E.; Hanssen, Arlen D.

    2012-01-01

    Identification of Corynebacterium species may be challenging. Corynebacterium species are occasional causes of prosthetic joint infection (PJI), but few data are available on the subject. Based on the literature, C. amycolatum, C. aurimucosum, C. jeikeium, and C. striatum are the most common Corynebacterium species that cause PJI. We designed a rapid PCR assay to detect the most common human Corynebacterium species, with a specific focus on PJI. A polyphosphate kinase gene identified using whole-genome sequence was targeted. The assay differentiates the antibiotic-resistant species C. jeikeium and C. urealyticum from other species in a single assay. The assay was applied to a collection of human Corynebacterium isolates from multiple clinical sources, and clinically relevant species were detected. The assay was then tested on Corynebacterium isolates specifically associated with PJI; all were detected. We also describe the first case of C. simulans PJI. PMID:22337986

  15. Slip joint connector

    NASA Technical Reports Server (NTRS)

    Thomas, Frank P. (inventor)

    1994-01-01

    A slip joint connector for joining first and second structural elements together is presented. The connector has a first body member attachable to the first structural element and a second body member attachable to the second structural element. The first body member has a male protuberance including a conical portion and the second body member has a conical receptacle for cooperatively receiving the conical portion of the protuberance. The protuberance includes a bridging portion for spacing the conical portion from the remainder of the first body member and the second body member has a well communicating with the conical receptacle for receiving the bridging portion. The conical male portion internally carries a nut while the second body member may receive a bolt through the receptacle to be threadedly received by the nut to secure the first and second body members tightly together.

  16. Foreign Fishery Developments Japanese Joint

    E-print Network

    the Japanese investment of $98.2 million (66.9 percent). In 1981, the capital value of these joint ven- tures in Central and South America was $51.5 million, which is 73 percent more than in 1980. The Japanese in of joint ven- tures with Japanese participation in Asia and Oceania was $55.9 million, which is 13 percent

  17. Industrial robots with seven joints

    Microsoft Academic Search

    J. Y. S. Luh; Y. L. Gu

    1985-01-01

    In a physical 3-dimensional free space at most six degrees of freedom can be independent, i.e. three for position and three for orientation. Intuitively robots with six joints are adequate to execute any tasks. However, in reality, constraints often exist under the complex environment so that six joints are not quite enough for the robots. An insertion of an additional

  18. [Arthroscopy of the metacarpophalangeal joints].

    PubMed

    Borisch, N

    2014-10-01

    With the advancements in arthroscopic technique, arthroscopy has become feasible in most human joints, even those as small as the finger joints. The metacarpophalangeal joints are very well suited for arthroscopy and arthroscopic therapy. Good results have been reported on arthroscopic synovectomy of the metacarpophalangeal joints in rheumatoid arthritis. Osteochondral lesions in degenerative arthritis, loose bodies and foreign bodies can well be treated. Arthroscopic arthrolysis for capsular contracture and treatment of post-traumatic lesions have been performed successfully. The arthroscopic assistance in the treatment of intraarticular fractures and the capsular shrinkage for instability have been described. However, metacarpophalangeal joint arthroscopy has not been popularised up to now and its role in clinical practice remains to be established. Existing indications will be discussed with respect to our own experience. PMID:25290276

  19. Method of forming a joint

    DOEpatents

    Butt, Darryl Paul; Cutler, Raymond Ashton; Rynders, Steven Walton; Carolan, Michael Francis

    2006-08-22

    A method of joining at least two sintered bodies to form a composite structure, including providing a first multicomponent metallic oxide having a perovskitic or fluorite crystal structure; providing a second sintered body including a second multicomponent metallic oxide having a crystal structure of the same type as the first; and providing at an interface a joint material containing at least one metal oxide containing at least one metal identically contained in at least one of the first and second multicomponent metallic oxides. The joint material is free of cations of Si, Ge, Sn, Pb, P and Te and has a melting point below the sintering temperatures of both sintered bodies. The joint material is heated to a temperature above the melting point of the metal oxide(s) and below the sintering temperatures of the sintered bodies to form the joint. Structures containing such joints are also disclosed.

  20. 11 CFR 9034.8 - Joint fundraising.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 2011-01-01 false Joint fundraising. 9034.8 Section 9034...MATCHING FUND ENTITLEMENTS § 9034.8 Joint fundraising. (a) General...funds under this subchapter may engage in joint fundraising with other candidates,...

  1. 24 CFR 570.308 - Joint requests.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...Development 3 2010-04-01 2010-04-01 false Joint requests. 570.308 Section 570.308 Housing...BLOCK GRANTS Entitlement Grants § 570.308 Joint requests. (a) Joint requests and cooperation agreements....

  2. 11 CFR 9034.8 - Joint fundraising.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 2010-01-01 false Joint fundraising. 9034.8 Section 9034...MATCHING FUND ENTITLEMENTS § 9034.8 Joint fundraising. (a) General...funds under this subchapter may engage in joint fundraising with other candidates,...

  3. 24 CFR 570.308 - Joint requests.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...Development 3 2011-04-01 2010-04-01 true Joint requests. 570.308 Section 570.308 Housing...BLOCK GRANTS Entitlement Grants § 570.308 Joint requests. (a) Joint requests and cooperation agreements....

  4. 30 CFR 36.24 - Engine joints.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Requirements § 36.24 Engine joints. (a) Cylinder head. The joint between the cylinder head...engine shall be fitted with a metal or metal-clad gasket satisfactory...change in alignment. This joint shall provide an...

  5. 30 CFR 36.24 - Engine joints.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Requirements § 36.24 Engine joints. (a) Cylinder head. The joint between the cylinder head...engine shall be fitted with a metal or metal-clad gasket satisfactory...change in alignment. This joint shall provide an...

  6. Performance modulation of ?-MnO2 nanowires by crystal facet engineering.

    PubMed

    Li, Wenxian; Cui, Xiangyuan; Zeng, Rong; Du, Guodong; Sun, Ziqi; Zheng, Rongkun; Ringer, Simon P; Dou, Shi Xue

    2015-01-01

    Modulation of material physical and chemical properties through selective surface engineering is currently one of the most active research fields, aimed at optimizing functional performance for applications. The activity of exposed crystal planes determines the catalytic, sensory, photocatalytic, and electrochemical behavior of a material. In the research on nanomagnets, it opens up new perspectives in the fields of nanoelectronics, spintronics, and quantum computation. Herein, we demonstrate controllable magnetic modulation of ?-MnO2 nanowires, which displayed surface ferromagnetism or antiferromagnetism, depending on the exposed plane. First-principles density functional theory calculations confirm that both Mn- and O-terminated ?-MnO2 (1 1 0) surfaces exhibit ferromagnetic ordering. The investigation of surface-controlled magnetic particles will lead to significant progress in our fundamental understanding of functional aspects of magnetism on the nanoscale, facilitating rational design of nanomagnets. Moreover, we approved that the facet engineering pave the way on designing semiconductors possessing unique properties for novel energy applications, owing to that the bandgap and the electronic transport of the semiconductor can be tailored via exposed surface modulations. PMID:25758232

  7. BSA Nanoparticle Loaded Atorvastatin Calcium - A New Facet for an Old Drug

    PubMed Central

    S, Sripriyalakshmi.; C. H, Anjali.; C, George Priya Doss.; B, Rajith; Ravindran, Aswathy

    2014-01-01

    Background Currently, the discovery of effective chemotherapeutic agents poses a major challenge to the field of cancer biology. The present study focuses on enhancing the therapeutic and anti cancer properties of atorvastatin calcium loaded BSA (ATV-BSA) nanoparticles in vitro. Methodology/Results BSA-ATV nanoparticles were prepared using desolvation technique. The process parameters were optimized based on the amount of desolvating agent, stabilization conditions as well as the concentration of the cross linker. The anti cancer properties of the protein coated ATV nanoparticles were tested on MiaPaCa-2 cell lines. In vitro release behavior of the drug from the carrier suggests that about 85% of the drug gets released after 72 hrs. Our studies show that ATV-BSA nanoparticles showed specific targeting and enhanced cytotoxicity to MiaPaCa-2 cells when compared to the bare ATV. Conclusion We hereby propose that the possible mechanism of cellular uptake of albumin bound ATV could be through caveolin mediated endocytosis. Hence our studies open up new facet for an existing cholesterol drug as a potent anti-cancer agent. PMID:24498272

  8. A brief history of defect formation, segregation, faceting, and twinning in melt-grown semiconductors

    NASA Astrophysics Data System (ADS)

    Hurle, D. T. J.; Rudolph, P.

    2004-03-01

    A historical review of the development of knowledge of defect formation in semiconductor crystals is given. The treatment starts with zero-dimensional defect types, especially native point defects in Si and GaAs. One-dimensional structural disturbances—dislocations and their patterning—are discussed next. Whereas in Si the total elimination of extended dislocations is well established, in semiconductor compounds, like III-Vs with low critical resolved shear stress, this seems to be impossible. In a further section micro- and macro-segregation phenomena—striations and the effects of constitutional supercooling—are reviewed. Finally, two-dimensional features are discussed. First the interplay between facets and inhomogeneous dopant incorporation is described. Then the problem of twinning, especially in InP, is outlined. The paper is focused on the grassroots from the beginning of the 1950s—the birth of semiconductor melt growth. For each defect type the current state of knowledge and methods of control are indicated. Problems remaining to be solved in the future are summarised.

  9. Treatment of bipolar disorder: a complex treatment for a multi-faceted disorder

    PubMed Central

    Fountoulakis, Konstantinos N; Vieta, Eduard; Siamouli, Melina; Valenti, Marc; Magiria, Stamatia; Oral, Timucin; Fresno, David; Giannakopoulos, Panteleimon; Kaprinis, George S

    2007-01-01

    Background Manic-depression or bipolar disorder (BD) is a multi-faceted illness with an inevitably complex treatment. Methods This article summarizes the current status of our knowledge and practice of its treatment. Results It is widely accepted that lithium is moderately useful during all phases of bipolar illness and it might possess a specific effectiveness on suicidal prevention. Both first and second generation antipsychotics are widely used and the FDA has approved olanzapine, risperidone, quetiapine, ziprasidone and aripiprazole for the treatment of acute mania. These could also be useful in the treatment of bipolar depression, but only limited data exists so far to support the use of quetiapine monotherapy or the olanzapine-fluoxetine combination. Some, but not all, anticonvulsants possess a broad spectrum of effectiveness, including mixed dysphoric and rapid-cycling forms. Lamotrigine may be effective in the treatment of depression but not mania. Antidepressant use is controversial. Guidelines suggest their cautious use in combination with an antimanic agent, because they are supposed to induce switching to mania or hypomania, mixed episodes and rapid cycling. Conclusion The first-line psychosocial intervention in BD is psychoeducation, followed by cognitive-behavioral therapy. Other treatment options include Electroconvulsive therapy and transcranial magnetic stimulation. There is a gap between the evidence base, which comes mostly from monotherapy trials, and clinical practice, where complex treatment regimens are the rule. PMID:17925035

  10. Examining the factor structures of the five facet mindfulness questionnaire and the self-compassion scale.

    PubMed

    Williams, Matthew J; Dalgleish, Tim; Karl, Anke; Kuyken, Willem

    2014-06-01

    The five facet mindfulness questionnaire (FFMQ; Baer, Smith, Hopkins, Krietemeyer, & Toney, 2006) and the self-compassion scale (SCS; Neff, 2003) are widely used measures of mindfulness and self-compassion in mindfulness-based intervention research. The psychometric properties of the FFMQ and the SCS need to be independently replicated in community samples and relevant clinical samples to support their use. Our primary aim was to establish the factor structures of the FFMQ and SCS in individuals with recurrent depression in remission, since mindfulness-based cognitive therapy (MBCT) was developed as a treatment for preventing depressive relapse. In order to determine the consistency across populations, we examined the factor structures of the FFMQ and SCS in 3 samples: (1) a convenience sample of adults, (2) a sample of adults who practice meditation, and (3) a sample of adults who suffer from recurrent depression and were recruited to take part in a trial of MBCT. Confirmatory factor analyses (CFAs) showed that a 4-factor hierarchical model of the FFMQ best fits the community sample and the clinical sample but that a 5-factor hierarchical model of the FFMQ best fits the meditator sample. CFA did not endorse the SCS 6-factor hierarchical structure in any of the 3 samples. Clinicians and researchers should be aware of the psychometric properties of the FFMQ to measure mindfulness when comparing meditators and nonmeditators. Further research is needed to develop a more psychometrically robust measure of self-compassion. PMID:24490681

  11. Adsorption induced faceting and superstructural phase diagram of the Sb/Si(5 5 12) interface

    NASA Astrophysics Data System (ADS)

    Kumar, Mahesh; Govind; Paliwal, V. K.; Vedeshwar, A. G.; Shivaprasad, S. M.

    2006-07-01

    The planar high index Si(5 5 12) surface consists of trenches formed by the several proximal surface planes, that can be employed as templates for the adsorption of low dimensional nanostructures. This paper reports the results of an extensive UHV study of the adsorption of Sb, in the sub-monolayer coverage regime, onto the Si(5 5 12) surface. The evolution of the surface phases, surface morphology and electronic structure is monitored by Auger Electron Spectroscopy (AES), Low Energy Electron Diffraction (LEED) and Electron Energy Loss Spectroscopy (EELS). A careful control of substrate temperatures and Sb coverages formed at a low flux rate of 0.06 ML/min enable us to extract a complete adsorption phase diagram of the important interface, for the first time. The phase diagram clearly demonstrates the conversion of the large Si(5 5 12) unit cell into facets of planes of smaller (2 2 5), (3 3 7) and (1 1 3) base units. The study also reveals the formation of various superstructural phases formed by steering the kinetic parameters.

  12. Direct Synthesis of Anatase Films with ~100% (001) Facets and [001] Preferred Orientation

    PubMed Central

    Ichimura, Andrew S.; Mack, Brianne; Usmani, Shirin M.; Mars, Diana

    2012-01-01

    Anatase films exhibiting ~100% (001) reactive facets at the surface were grown hydrothermally on gold substrate from a homogeneous solution of TiF4 and NaF. In addition to NaF, it was found that TiO2 films with very similar properties could be prepared with the fluoride salts LiF, CsF, HF, NH4F, and N(CH2CH3)4F. The polycrystalline anatase films are continuous, approximately 1 ?m thick, and evenly coat the substrate. The surface grain size is ~400 nm. Grazing angle XRD measurements show that the films exhibit a high degree of preferred orientation with the c-axis normal to the substrate surface. SEM images reveal that the grains span the thickness of the films. Annealing the films at 500 °C removes fluorine and causes crystallites within the grains to restructure as shown by SEM, XRD, and Raman spectroscopy. Supported anatase films grown from this one-pot method may serve as oxidative photocatalysts and electrodes for photoelectrochemical applications such as solar cells and hydrogen evolution. PMID:22844184

  13. Performance modulation of ?-MnO2 nanowires by crystal facet engineering

    PubMed Central

    Li, Wenxian; Cui, Xiangyuan; Zeng, Rong; Du, Guodong; Sun, Ziqi; Zheng, Rongkun; Ringer, Simon P.; Dou, Shi Xue

    2015-01-01

    Modulation of material physical and chemical properties through selective surface engineering is currently one of the most active research fields, aimed at optimizing functional performance for applications. The activity of exposed crystal planes determines the catalytic, sensory, photocatalytic, and electrochemical behavior of a material. In the research on nanomagnets, it opens up new perspectives in the fields of nanoelectronics, spintronics, and quantum computation. Herein, we demonstrate controllable magnetic modulation of ?-MnO2 nanowires, which displayed surface ferromagnetism or antiferromagnetism, depending on the exposed plane. First-principles density functional theory calculations confirm that both Mn- and O-terminated ?-MnO2 (1 1 0) surfaces exhibit ferromagnetic ordering. The investigation of surface-controlled magnetic particles will lead to significant progress in our fundamental understanding of functional aspects of magnetism on the nanoscale, facilitating rational design of nanomagnets. Moreover, we approved that the facet engineering pave the way on designing semiconductors possessing unique properties for novel energy applications, owing to that the bandgap and the electronic transport of the semiconductor can be tailored via exposed surface modulations. PMID:25758232

  14. Performance modulation of ?-MnO2 nanowires by crystal facet engineering

    NASA Astrophysics Data System (ADS)

    Li, Wenxian; Cui, Xiangyuan; Zeng, Rong; Du, Guodong; Sun, Ziqi; Zheng, Rongkun; Ringer, Simon P.; Dou, Shi Xue

    2015-03-01

    Modulation of material physical and chemical properties through selective surface engineering is currently one of the most active research fields, aimed at optimizing functional performance for applications. The activity of exposed crystal planes determines the catalytic, sensory, photocatalytic, and electrochemical behavior of a material. In the research on nanomagnets, it opens up new perspectives in the fields of nanoelectronics, spintronics, and quantum computation. Herein, we demonstrate controllable magnetic modulation of ?-MnO2 nanowires, which displayed surface ferromagnetism or antiferromagnetism, depending on the exposed plane. First-principles density functional theory calculations confirm that both Mn- and O-terminated ?-MnO2 (1 1 0) surfaces exhibit ferromagnetic ordering. The investigation of surface-controlled magnetic particles will lead to significant progress in our fundamental understanding of functional aspects of magnetism on the nanoscale, facilitating rational design of nanomagnets. Moreover, we approved that the facet engineering pave the way on designing semiconductors possessing unique properties for novel energy applications, owing to that the bandgap and the electronic transport of the semiconductor can be tailored via exposed surface modulations.

  15. Faceting control in core-shell GaN micropillars using selective epitaxy

    NASA Astrophysics Data System (ADS)

    Krylyuk, Sergiy; Debnath, Ratan; Yoon, Heayoung P.; King, Matthew R.; Ha, Jong-Yoon; Wen, Baomei; Motayed, Abhishek; Davydov, Albert V.

    2014-10-01

    We report on the fabrication of large-area, vertically aligned GaN epitaxial core-shell micropillar arrays. The two-step process consists of inductively coupled plasma (ICP) etching of lithographically patterned GaN-on-Si substrate to produce an array of micropillars followed by selective growth of GaN shells over these pillars using Hydride Vapor Phase Epitaxy (HVPE). The most significant aspect of the study is the demonstration of the sidewall facet control in the shells, ranging from {1 1 ¯ 01} semi-polar to {1 1 ¯ 00} non-polar planes, by employing a post-ICP chemical etch and by tuning the HVPE growth temperature. Room-temperature photoluminescence, cathodoluminescence, and Raman scattering measurements reveal substantial reduction of parasitic yellow luminescence as well as strain-relaxation in the core-shell structures. In addition, X-ray diffraction indicates improved crystal quality after the shell formation. This study demonstrates the feasibility of selective epitaxy on micro-/nano- engineered templates for realizing high-quality GaN-on-Si devices.

  16. Attention deficit hyperactivity disorder (ADHD) and obesity: two facets of the same disease?

    PubMed

    Odent, Michel

    2010-01-01

    We hypothesize that when two pathological conditions or personality traits share the same critical period for gene-environment interaction, we should expect further similarities, particularly from clinical and pathophysiological perspectives. They should therefore be considered as two facets of the same disease. To test this hypothesis we compiled data included in the Primal Health Research Database. This database (www.primalhealthresearch.com) is specialised in studies exploring correlations between what happens during the 'primal period' (fetal life, perinatal period and year following birth) and what happens later on in life in terms of health and personality traits. After mentioning the links between autism and anorexia nervosa, we explore more in depth the links between attention deficit hyperactivity disorder (ADHD) and obesity. We suggest from such examples that the nature of an environmental factor is often less important than the timing of the interaction. We conclude that the concept of gene expression, combined with Primal Health Research, might lead to reconsider conventional nosological classifications. Some previously well-defined pathological entities should be included into the framework of multifaceted diseases. On the other hand some existing pathological entities should be dismantled. PMID:19665851

  17. A mitocentric view of Alzheimer's disease suggests multi-faceted treatments.

    PubMed

    Gibson, Gary E; Shi, Qingli

    2010-01-01

    Alzheimer's disease (AD) is defined by senile plaques made of amyloid-beta peptide (Abeta), neurofibrillary tangles made of hyperphosphorylated tau proteins, and memory deficits. Thus, the events initiating the cascade leading to these end points may be more effective therapeutic targets than treating each facet individually. In the small percentage of cases of AD that are genetic (or animal models that reflect this form of AD), the factor initiating AD is clear (e.g., genetic mutations lead to high Abeta1-42 or hyperphosphorylated tau proteins). In the vast majority of AD cases, the cause is unknown. Substantial evidence now suggests that abnormalities in glucose metabolism/mitochondrial function/oxidative stress (GMO) are an invariant feature of AD and occur at an early stage of the disease process in both genetic and non-genetic forms of AD. Indeed, decreases in brain glucose utilization are diagnostic for AD. Changes in calcium homeostasis also precede clinical manifestations of AD. Abnormal GMO can lead to plaques, tangles, and the calcium abnormalities that accompany AD. Abnormalities in GMO diminish the ability of the brain to adapt. Therapies targeting mitochondria may ameliorate abnormalities in plaques, tangles, calcium homeostasis, and cognition that comprise AD. PMID:20463407

  18. Quality Analysis on Ransac-Based Roof Facets Extraction from Airborne LIDAR Data

    NASA Astrophysics Data System (ADS)

    Yan, J.; Jiang, W.; Shan, J.

    2012-07-01

    RANSAC algorithm is a robust method for model estimation. It is widely used in the extraction of geometry primitives and 3D model reconstruction. However, there has been relatively little comprehensive evaluation in RANSAC-based approach for plane extraction. In order to provide a reference for improving the quality on RANSAC-based approach for roof facets extraction or segmentation, this paper focuses on the quality analysis on classical RANSAC algorithm. Airborne LIDAR data from the test Area 1 and Area 2 in Vaihingen (German) is used. 33 buildings (4 buildings with flat roofs and 29 buildings with slope roofs) extracted from LIDAR data are taken as input for planes extraction. Based on the characteristics of detected planar surfaces, planes can fall into several categories: non-segmented planes, over-segmented planes, under-segmented planes and spurious planes. Then, several causes for these quality problems are discussed. Some experimental results and analyses show that, considering spatial-domain connectivity, most of the quality problems of classical RANSAC algorithm can be improved. However, there are still many issues requiring in-depth research. Finally, some methods are suggested to solve these problems.

  19. Chiral symmetry breaking and surface faceting in chromonic liquid crystal droplets with giant elastic anisotropy.

    PubMed

    Jeong, Joonwoo; Davidson, Zoey S; Collings, Peter J; Lubensky, Tom C; Yodh, A G

    2014-02-01

    Confined liquid crystals (LC) provide a unique platform for technological applications and for the study of LC properties, such as bulk elasticity, surface anchoring, and topological defects. In this work, lyotropic chromonic liquid crystals (LCLCs) are confined in spherical droplets, and their director configurations are investigated as a function of mesogen concentration using bright-field and polarized optical microscopy. Because of the unusually small twist elastic modulus of the nematic phase of LCLCs, droplets of this phase exhibit a twisted bipolar configuration with remarkably large chiral symmetry breaking. Further, the hexagonal ordering of columns and the resultant strong suppression of twist and splay but not bend deformation in the columnar phase, cause droplets of this phase to adopt a concentric director configuration around a central bend disclination line and, at sufficiently high mesogen concentration, to exhibit surface faceting. Observations of director configurations are consistent with Jones matrix calculations and are understood theoretically to be a result of the giant elastic anisotropy of LCLCs. PMID:24449880

  20. Chiral symmetry breaking and surface faceting in chromonic liquid crystal droplets with giant elastic anisotropy

    PubMed Central

    Jeong, Joonwoo; Davidson, Zoey S.; Collings, Peter J.; Lubensky, Tom C.; Yodh, A. G.

    2014-01-01

    Confined liquid crystals (LC) provide a unique platform for technological applications and for the study of LC properties, such as bulk elasticity, surface anchoring, and topological defects. In this work, lyotropic chromonic liquid crystals (LCLCs) are confined in spherical droplets, and their director configurations are investigated as a function of mesogen concentration using bright-field and polarized optical microscopy. Because of the unusually small twist elastic modulus of the nematic phase of LCLCs, droplets of this phase exhibit a twisted bipolar configuration with remarkably large chiral symmetry breaking. Further, the hexagonal ordering of columns and the resultant strong suppression of twist and splay but not bend deformation in the columnar phase, cause droplets of this phase to adopt a concentric director configuration around a central bend disclination line and, at sufficiently high mesogen concentration, to exhibit surface faceting. Observations of director configurations are consistent with Jones matrix calculations and are understood theoretically to be a result of the giant elastic anisotropy of LCLCs. PMID:24449880

  1. Deletion of an insulator element by the mutation facet-strawberry in Drosophila melanogaster.

    PubMed Central

    Vazquez, J; Schedl, P

    2000-01-01

    Eukaryotic chromosomes are thought to be subdivided into a series of structurally and functionally independent units. Critical to this hypothesis is the identification of insulator or boundary elements that delimit chromosomal domains. The properties of a Notch mutation, facet-strawberry (fa(swb)), suggest that this small deletion disrupts such a boundary element. fa(swb) is located in the interband separating polytene band 3C7, which contains Notch, from the distal band 3C6. The fa(swb) mutation alters the structural organization of the chromosome by deleting the interband and fusing 3C7 with 3C6. Genetic studies also suggest that fa(swb) compromises the functional autonomy of Notch by allowing the locus to become sensitive to chromosomal position effects emanating from distal sequences. In the studies reported here, we show that a DNA fragment spanning the fa(swb) region can insulate reporter transgenes against chromosomal position effects and can block enhancer-promoter interactions. Moreover, we find that insulating activity is dependent on sequences deleted in fa(swb). These results provide evidence that the element defined by the fa(swb) mutation corresponds to an insulator. PMID:10880489

  2. Unique excavated rhombic dodecahedral PtCu3 alloy nanocrystals constructed with ultrathin nanosheets of high-energy {110} facets.

    PubMed

    Jia, Yanyan; Jiang, Yaqi; Zhang, Jiawei; Zhang, Lei; Chen, Qiaoli; Xie, Zhaoxiong; Zheng, Lansun

    2014-03-12

    Ultrathin crystalline nanosheets give an extremely high surface area of a specific crystal facet with unique physical and chemical properties compared with normal three-dimensionally polyhedral nanocrystals (NCs). However, the ultrathin metal nanosheets tend to curl themselves or assemble with each other sheet by sheet, which may reduce the effective surface area and accordingly the catalytic activity to a great extent. Here we report a facile wet-chemical route that allows the fabrication of novel excavated rhombic dodecahedral (ERD) PtCu3 alloy NCs with ultrathin nanosheets of high-energy {110} facets. The surface area was measured to be 77 m(2) g(-1) by CO stripping, although the particle size is about 50 nm. Electrochemical characterizations showed that the ERD PtCu3 NCs exhibit excellent electrocatalytic performance and high antipoisoning activity in comparison with commercial Pt black and PtCu3 alloy NCs with {111} surfaces. PMID:24580027

  3. Compliant Prosthetic Or Robotic Joint

    NASA Technical Reports Server (NTRS)

    Kerley, James J.; Eklund, Wayne D.

    1989-01-01

    Rotation partly free and partly restrained by resilience and damping. Joint includes U-shaped x- and y-axis frames joined by cables that cross in at center piece. The y-axis frame rotates about y-axis on roller bearing within predetermined angular range. The y-axis frame rotates slightly farther when arm strikes stop, because cables can twist. This mimics compliant resistance of knee joint reaching limit of its forward or backward motion. Used in prosthetic device to replace diseased or damage human joint, or in robot linkage to limit movement and cushion overloads.

  4. Multi-mode waveguides from ultra-long self-assembled hexagonal faceted microtubules of a benzothiadiazole molecule.

    PubMed

    Balakrishnan, Kaushik; Sayyad, Arshad S; Myhre, Graham; Mataka, Shuntaro; Pau, Stanley

    2012-12-11

    Length controlled (?m-mm-cm) self-assembly of hexagonal faceted microtubules has been achieved using a phase-transfer solution processing approach from . The self-assembled structures exhibit both polarized light emission and multi-mode waveguide properties over large length scales. The multi-mode waveguide characteristics are analyzed using a combination of experiment and finite-difference-time-domain calculations. PMID:23099881

  5. Right-Wing Authoritarianism and Social Dominance Orientation Their Roots in Big-Five Personality Factors and Facets

    Microsoft Academic Search

    Nazar Akrami; Bo Ekehammar

    Extending previous research on the relation of Big-Five personality with right-wing authoritarianism and social dominance orientation, we examined the relationships of Big-Five facet scores rather than factor scores. The results (N = 332) of stepwise regression analyses showed that Openness to Experience was the only significant predictor of right-wing authoritarianism at the factor level, whereas Values and Ideas were significant

  6. Acromioclavicular joint cyst formation.

    PubMed

    Hiller, Andrew D; Miller, Joshua D; Zeller, John L

    2010-03-01

    Acromioclavicular joint (ACJ) cysts are an uncommon and unusual sequela associated with shoulder pathophysiology. The majority of literature on ACJ cysts consists of individual case reports with no definitive literature review currently available. In addition to a comprehensive literature review, four clinical cases are presented in this report. First described by Craig (1984), a total of 41 cases have been previously reported in the literature. Of these cases, five occurred with the rotator cuff musculature intact. The remaining 36 cases of ACJ cysts occurred in patients with a complete tear/avulsion of the rotator cuff. Previous attempts at compiling a complete record of all reported cases have combined several distinct conditions into a single category. This article presents two distinct etiologies for the pathogenesis of ACJ cyst formation. In the presence of an intact rotator cuff, a Type 1 cyst can form superficially and be limited to the ACJ. Following a massive or traumatic tear of the rotator cuff, mechanical instability of the humeral head can cause a deterioration of the inferior acromioclavicular capsule (cuff tear arthropathy) and an overproduction of synovial fluid. Overtime, a "geyser" of fluid can form between the glenohumeral and the ACJ, forming a Type 2 cyst. This differentiation and categorization is essential for appropriate classification and treatment. PMID:20069645

  7. Stable platinum nanoparticles on specific MgAl2O4 spinel facets at high temperatures in oxidizing atmospheres

    SciTech Connect

    Li, Wei-Zhen; Kovarik, Libor; Mei, Donghai; Liu, Jun; Wang, Yong; Peden, Charles HF

    2013-09-25

    The development of thermally stable, nanometer-sized precious metal based catalysts remains a daunting challenge. Such materials, especially those based on the use of costly platinum metal, are essential and, to date, non-replaceable for a large number of industrially important catalytic processes. Here we report a well-defined cuboctahedral MgAl2O4 spinel support material that is capable of stabilizing platinum particles in the range of 1-3 nm on its relatively abundant {111} facets during extremely severe aging at 800°C in air for 1 week (168 h). The aged catalysts retain platinum dispersions of 15.9% with catalytic activities for methanol oxidation approximately 80% of fresh ones, while a conventional Pt/?-Al2O3 catalyst is severely sintered and nearly inactive. We reveal the origin of the markedly superior ability of spinel {111} facets, resulting from strong interactions between spinel surface oxygens and epitaxial platinum {111} facets, inspiring the rational design of anti-sintering supported platinum group catalysts. This work was supported by U. S. Department of Energy (DOE), Office of Basic Energy Sciences, Division of Chemical Sciences, Biosciences and Geosciences. The research was performed in the Environmental Molecular Sciences Laboratory, a national scientific user facility sponsored by the DOE Office of Biological and Environmental Research, and located at Pacific Northwest National Laboratory. PNNL is operated for DOE by Battelle.

  8. Epitaxial growth of ZnO Nanodisks with large exposed polar facets on nanowire arrays for promoting photoelectrochemical water splitting.

    PubMed

    Chen, Haining; Wei, Zhanhua; Yan, Keyou; Bai, Yang; Zhu, Zonglong; Zhang, Teng; Yang, Shihe

    2014-11-01

    Single-crystalline and branched 1D arrays, ZnO nanowires/nanodisks (NWs/NDs) arrays, are fabricated to significantly enhance the performance of photoelectrochemical (PEC) water splitting. The epitaxial growth of the ZnO NDs with large exposed polar facets on ZnO NWs exhibits a laminated structure, which dramatically increases the light scattering capacity of the NWs arrays, especially in the wavelength region around 400 nm. The ND branching of the 1D arrays in the epitaxial fashion not only increase surface area and light utilization, but also support fast charge transport, leading to the considerable increase of photocurrent. Moreover, the tiny size NDs can facilitate charge separation and reduce charge recombination, while the large exposed polar facets of NDs reduce the external potential bias needed for water splitting. These advantages land the ZnO NWs/NDs arrays a four times higher power conversion efficiency than the ZnO NWs arrays. By sensitizing the ZnO NWs/NDs with CdS and CdSe quantum dots, the PEC performance can be further improved. This work advocates a trunk/leaf in forest concept for the single-crystalline NWs/NDs in array with enlarged exposure of polar facets, which opens the way for optimizing light harvesting and charge separation and transport, and thus the PEC water splitting. PMID:24990800

  9. Examination of the trait facets of the five-factor model in discriminating specific mood and anxiety disorders.

    PubMed

    Rector, Neil A; Bagby, Robert Michael; Huta, Veronika; Ayearst, Lindsay E

    2012-09-30

    Structural models of the mood and anxiety disorders postulate that each disorder has a shared component that can account for comorbidity and its own unique component that distinguishes it from others. The principal aim of the current study was to determine the extent to which the 30 facets of the Five-Factor Model (FFM), as measured by the Revised NEO Personality Inventory (NEO PI-R), contribute to the identification of the unique component in mood and anxiety disorders in treatment-seeking clinical samples. Participants (N=610) were psychiatric outpatients with principal DSM-IV diagnoses (Diagnostic and Statistical Manual-IV; American Psychiatric Association, 1994) diagnoses of major depressive disorder (MDD), post-traumatic stress disorder (PTSD), generalized social phobia (GSP), panic disorder with/without agoraphobia (PD; PD/A) or obsessive-compulsive disorder (OCD). Results suggest that approximately half of the variance in differences between these diagnoses is associated with specific characteristics represented by the FFM facets. Unique personality profiles for the MDD, GSP, PTSD and, to a lesser extent, OCD groups emerged. Broad traits of the FFM, when broken into more narrow components at the facet level, contribute significantly to the identification of unique aspects associated with specific mood and anxiety disorders. The integration of lower and higher levels of structural examination of the mood and anxiety disorders is discussed. PMID:22595418

  10. Spherical and sheetlike Ag/AgCl nanostructures: interesting photocatalysts with unusual facet-dependent yet substrate-sensitive reactivity.

    PubMed

    Shen, Yunfan; Chen, Penglei; Xiao, Dan; Chen, Chuncheng; Zhu, Mingshan; Li, Tiesheng; Ma, Wangong; Liu, Minghua

    2015-01-13

    We herein report that spherical and sheetlike Ag/AgCl nanostructures could be controllably synthesized by means of chemical reactions between AgNO3 and cetyltrimethylammonium chloride (CTAC) surfactant. In this synthesis system, AgNO3 works as the silver source, while CTAC serves not only as the chlorine source but also as the directing reagent for a controllable nanofabrication. We show that compared to the spherical Ag/AgCl nanostructures, the sheetlike counterparts, wherein the AgCl nanospecies are predominantly enriched with {111} facets, could exhibit superior catalytic performances toward the photodegradation of methyl orange. Interestingly, we further demonstrate that when 4-chlorophenol or phenol is used as the substrate, the sheetlike Ag/AgCl nanostructures exhibit inferior catalytic reactivity, whereas the spherical counterparts display superior catalytic performances comparatively. Our results disclose new insights on the facet-dependent catalytic performances with regard to a facet-selective but substrate-sensitive photoinduced electron-hole separation. PMID:25487042

  11. Controllable defect redistribution of ZnO nanopyramids with exposed {101?1} facets for enhanced gas sensing performance.

    PubMed

    Wang, Zhihua; Xue, Jie; Han, Dongmei; Gu, Fubo

    2015-01-14

    ZnO nanopyramids (NPys) with exposed crystal facets of {101?1} were synthesized via a one-step solvothermal method, having a uniform size with a hexagonal edge length of ?100 nm and a height of ?200 nm. Technologies of XRD, TEM, HRTEM, Raman, PL, and XPS were used to characterize the morphological and structural properties of the products, while the corresponding gas sensing properties were determined by using ethanol as the target gas. For the overall goal of defect engineering, the effect of aging temperature on the gas sensing performance of the ZnO NPys was studied. The test results showed that, at the aging temperature of 300 °C, the gas sensing property has been improved to the best, with the fast response-recovery time and the excellent selectivity, because the ZnO300 has the most electron donors for absorbing the largest content of O(2-). Model of defect redistribution was used to explicate the changing of the surface defects at different aging temperatures. The findings showed that, in addition to VO, Zni was the dominant defect of the {101?1} crystal facet. The gas sensing performance of the ZnO NPys was determined by the contents of VO and Zni, with all of the defects redistributed on the surface. All of the results will be noticeable for the improvement of the sensing performance of materials with special crystal facet exposing. PMID:25457192

  12. arXiv:0810.3042v1[physics.bio-ph]16Oct2008 Single-domain protein folding: a multi-faceted

    E-print Network

    Ritort, Felix

    arXiv:0810.3042v1[physics.bio-ph]16Oct2008 Single-domain protein folding: a multi-faceted problem protein-like models can help to understand many controversial issues. Keywords: Protein folding, energy

  13. Non-linear joint dynamics and controls of jointed flexible structures with active and viscoelastic joint actuators

    Microsoft Academic Search

    H. S. Tzou

    1990-01-01

    Studies on joint dominated flexible space structures have attracted much interest recently due to the rapid developments in large deployable space systems. This paper describes a study of the non-linear structural dynamics of jointed flexible structures with initial joint clearance and subjected to external excitations. Methods of using viscoelastic and active vibration control technologies, joint actuators, to reduce dynamic contact

  14. Campus/Industry Joint Ventures.

    ERIC Educational Resources Information Center

    McDonald, Eugene J.

    1985-01-01

    Opportunities for joint economic ventures of colleges and industry are discussed, and a variety of ventures undertaken by Duke University are outlined, including a health club, hotel, and office building. Tax and financing considerations are noted. (MSE)

  15. Coupled behavior of rock joints

    SciTech Connect

    Tsang, Chin-Fu.

    1990-02-01

    The behavior of rock joints under various coupled processes is reviewed under four broad categories: hydromechanical processes, thermohydromechanical processes, hydromechanical-chemical processes, and thermomechanical-hydrochemical processes. The state-of-the-art and possible directions of further research in these coupled processes are discussed. Rock joint behaviors considered include not only dilation, closure, shear and joint propagation, but also changes in flow permeability and chemical sorption and retardation capabilities. These properties are of critical concern in practical considerations of the rock mass as a medium to store and isolate chemical and radioactive wastes. Investigations of coupled processes in two-fracture systems and multi-fracture systems are pointed out as interesting areas for future research. The need to consider coupled processes in borehole testing procedures involving rock joints is emphasized. 70 refs., 12 figs.

  16. The complexity of joint computation

    E-print Network

    Drucker, Andrew Donald

    2012-01-01

    Joint computation is the ubiquitous scenario in which a computer is presented with not one, but many computational tasks to perform. A fundamental question arises: when can we cleverly combine computations, to perform them ...

  17. Joint probabilities and quantum cognition

    SciTech Connect

    Acacio de Barros, J. [Liberal Studies, 1600 Holloway Ave., San Francisco State University, San Francisco, CA 94132 (United States)

    2012-12-18

    In this paper we discuss the existence of joint probability distributions for quantumlike response computations in the brain. We do so by focusing on a contextual neural-oscillator model shown to reproduce the main features of behavioral stimulus-response theory. We then exhibit a simple example of contextual random variables not having a joint probability distribution, and describe how such variables can be obtained from neural oscillators, but not from a quantum observable algebra.

  18. Facets, indium distribution, and lattice distortion of InGaAs\\/GaAs quantum dots observed by three-dimensional scanning transmission electron microscope

    Microsoft Academic Search

    Kazunari Ozasa; Yoshinobu Aoyagi; Masaya Iwaki; Hiroki Kurata

    2003-01-01

    Multiazimuth 360° observation of InGaAs\\/GaAs quantum dots (QDs) was performed with a 300 kV scanning transmission electron microscope, where both cross-sectional and plan-view images of the same specific QDs can be taken for a single specimen. The facet structure of truncated pyramids was reconstructed from facet-enhanced bright-field images newly observed with the incident axes slightly off from or , resulting

  19. Model Fusion and Joint Inversion

    NASA Astrophysics Data System (ADS)

    Haber, Eldad; Holtzman Gazit, Michal

    2013-09-01

    Inverse problems are inherently non-unique, and regularization is needed to obtain stable and reasonable solutions. The regularization adds information to the problem and determines which solution, out of the infinitely many, is obtained. In this paper, we review and discuss the case when a priori information exists in the form of either known structure or in the form of another inverse problem for a different property. The challenge is to include such information in the inversion process. To use existing known structure, we review the concept of model fusion, where we build a regularization functional that fuses the inverted model to a known one. The fusion is achieved by four different techniques. Joint inversion of two data sets is achieved by using iterative data fusion. The paper discusses four different methods for joint inversion. We discuss the use of correspondence maps or the petrophysics of the rocks, as well as structure. In particular, we suggest to further stabilize the well-known gradient cross product and suggest a new technique, Joint Total Variation, to solve the problem. The Joint Total Variation is a convex functional for joint inversion and, as such, has favorable optimization properties. We experiment with the techniques on the DC resistivity problem and the borehole tomography and show how model fusion and joint inversion can significantly improve over existing techniques.

  20. Faceting of Nanocrystals during Chemical Transformation: FromSolid Silver Spheres to Hollow Gold Octahedra

    SciTech Connect

    Yin, Yadong; Erdonmez, Can; Alivisatos, A. Paul

    2006-06-23

    Sustained progress in nanocrystal synthesis has enabled recent use of these materials as inorganic, macromolecular precursors that can be chemically transformed into new nanostructures. The literature now contains several cases with chemical transformations being accompanied by varying degrees of modification of properties, including crystal structure and particle shape. As a recent example, we demonstrated that as-synthesized metallic nanocrystals yield, upon oxidation, nanostructures with modified morphologies such as hollow particles. This morphological change derives from directional material flows due to differing diffusivities for the reacting atomic species, in a nanoscale version of the well-known Kirkendall Effect. This general methodology has since been extended by other groups to produce nanostructures with various compositions and shapes. We demonstrate that performing a replacement reaction on single crystalline Ag nanospheres of {approx}10 nm in diameter in an organic solvent produces hollow Au nanocrystals with an octahedral shape. Different from those Au shells made by starting with Ag particles about one order of magnitude larger, which largely reproduce that of the sacrificial Ag counterparts, the hollow nanocrystals obtained in this work show significant changes in the external morphology from the spherical Ag precursors. This evolution of a faceted external morphology during chemical transformation is made possible by the enhanced role of surface effects in our smaller nanocrystals. The competition between the Au atom deposition and Ag atom dissolution on various nanocrystal surfaces is believed to determine the final octahedral shape of the hollow Au nanocrystals. Simultaneous achievement of surface-mediated shape control and a hollow morphology in a one-pot, single-step synthetic procedure in this study promises an avenue to finer tuning of particle morphology, and thus physical properties such as surface plasmon resonance.