The development of a tensile-shear punch correlation for yield properties of model austenitic alloys
Energy Technology Data Exchange (ETDEWEB)
Hankin, G.L.; Faulkner, R.G. [Loughborough Univ. (United Kingdom); Hamilton, M.L.; Garner, F.A. [Pacific Northwest National Lab., Richland, WA (United States)
1997-08-01
The effective shear yield and maximum strengths of a set of neutron-irradiated, isotopically tailored austentic alloys were evaluated using the shear punch test. The dependence on composition and neutron dose showed the same trends as were observed in the corresponding miniature tensile specimen study conducted earlier. A single tensile-shear punch correlation was developed for the three alloys in which the maximum shear stress or Tresca criterion was successfully applied to predict the slope. The correlation will predict the tensile yield strength of the three different austenitic alloys tested to within {+-}53 MPa. The accuracy of the correlation improves with increasing material strength, to within {+-} MPa for predicting tensile yield strengths in the range of 400-800 MPa.
The development of a tensile-shear punch correlation for yield properties of model austenitic alloys
International Nuclear Information System (INIS)
Hankin, G.L.; Faulkner, R.G.; Hamilton, M.L.; Garner, F.A.
1997-01-01
The effective shear yield and maximum strengths of a set of neutron-irradiated, isotopically tailored austentic alloys were evaluated using the shear punch test. The dependence on composition and neutron dose showed the same trends as were observed in the corresponding miniature tensile specimen study conducted earlier. A single tensile-shear punch correlation was developed for the three alloys in which the maximum shear stress or Tresca criterion was successfully applied to predict the slope. The correlation will predict the tensile yield strength of the three different austenitic alloys tested to within ±53 MPa. The accuracy of the correlation improves with increasing material strength, to within ± MPa for predicting tensile yield strengths in the range of 400-800 MPa
Directory of Open Access Journals (Sweden)
Jussi Ruponen
2015-04-01
Full Text Available The purpose of this work was to determine the optimal welding time for linear friction welding of birch (Betula pendula L. wood while keeping the other parameters constant and at similar levels compared to other species in a similar density range. Specimens with dimensions of 20 × 5 × 150 mm3 were welded together, and the influence of welding time (2.5, 3.0, 3.5, and 4.0 s on the mechanical properties of the specimens was determined. The studies included a tensile-shear strength test as well as visual estimation of wood failure percentage (WFP. Additionally, X-ray microtomographic imaging was used to investigate and characterise the bond line properties as a non-destructive testing method. The highest mean tensile-shear strength, 7.9 MPa, was reached with a welding time of 3.5 s. Generally, all four result groups showed high, yet decreasing proportional standard deviations as the welding time increased. X-ray microtomographic images and analysis express the heterogeneity of the weld line clearly as well. According to the averaged group-wise results, WFP and tensile-shear strength correlated positively with an R2 of 0.93. An extrapolation of WFP to 65% totals a tensile-shear strength of 10.6 MPa, corresponding to four common adhesive bonds determined for beech.
On the correlation between minimum thickness and central deflection during small punch test
International Nuclear Information System (INIS)
Kumar, Pradeep; Chattopadhyay, J.; Dutta, B.K.
2016-01-01
Present paper deals with a detailed study on the correlation between minimum thickness (t/t_0) and central deflection (δ/t_0). Such data are obtained during the deformation of a small punch test of miniaturized specimen. Finite element studies have been carried out to investigate the effect of various parameters which are expected to influence this correlation. The parameters under consideration are material hardening, material yield stress, coefficient of friction and initial thickness of the specimen. It is shown that the correlation remains unaffected with respect to change in material parameters. Similarly, the coefficient of friction beyond 0.2 also does not affect the correlation. However, change in thickness has significant effect on the correlation. A modification has been suggested in the existing correlation to consider the influence of thickness change. The modified correlation is then used to calculate fracture toughness using the experimental results quoted in the literature. It is shown that the modified correlation improves the fracture toughness prediction considerably.
DEFF Research Database (Denmark)
Qing, Hai
2013-01-01
The influence of interface strength and loading conditions on the mechanical behavior of the metal-matrix composites is investigated in this paper. A program is developed to generate automatically 2D micromechanical Finite element (FE) models including interface, in which both the locations...... and dimensions of Silicon-Carbide (SiC) particles are randomly distributed. Finite element simulations of the deformation and damage evolution of SiC particle reinforced Aluminum (Al) alloy composite are carried out for different microstructures and interphase strengths under tensile, shear and combined tensile....../shear loads. 2D cohesive element is applied to describe the fracture and failure process of interphase, while the damage models based on maximum principal stress criterion and the stress triaxial indicator are developed within Abaqus/Standard Subroutine USDFLD to simulate the failure process of SiC particles...
Fracture-based correlation of uniaxial and small punch creep data
Czech Academy of Sciences Publication Activity Database
Dobeš, Ferdinand; Dymáček, Petr
2016-01-01
Roč. 86, DEC (2016), s. 34-38 ISSN 0167-8442 R&D Projects: GA MŠk LM2015069; GA MŠk(CZ) LQ1601 Institutional support: RVO:68081723 Keywords : Creep * Small punch test * Chromium steel Subject RIV: JG - Metallurgy Impact factor: 2.659, year: 2016
Energy Technology Data Exchange (ETDEWEB)
Karthik, V., E-mail: karthik@igcar.gov.in [Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamil Nadu 603102 (India); Laha, K.; Parameswaran, P.; Chandravathi, K.S.; Kasiviswanathan, K.V.; Jayakumar, T.; Raj, Baldev [Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamil Nadu 603102 (India)
2011-10-15
Modified 9Cr-1Mo ferritic steel (P91) is subjected to a series of heat treatments consisting of soaking for 5 min at the selected temperatures in the range 973 K-1623 K (below Ac{sub 1} to above Ac{sub 4}) followed by oil quenching and tempering at 1033 K for 1 h to obtain different microstructural conditions. The tensile properties of the different microstructural conditions are evaluated from small volumes of material by shear punch test technique. A new methodology for evaluating yield strength, ultimate tensile strength and strain hardening exponent from shear punch test by using correlation equations without employing empirical constants is presented and validated. The changes in the tensile properties are related to the microstructural changes of the steel investigated by electron microscopic studies. The steel exhibits minimum strength and hardness when soaked between Ac{sub 1} and Ac{sub 3} (intercritical range) temperatures due to the replacement of original lath martensitic structure with subgrains. The finer martensitic microstructure produced in the steel after soaking at temperatures above Ac{sub 3} leads to a monotonic increase in hardness and strength with decreasing strain hardening exponent. For soaking temperatures above Ac{sub 4}, the hardness and strength of the steel increases marginally due to the formation of soft {delta} ferrite. - Highlights: > A methodology presented for computing tensile properties from shear punch test. > UTS and strain hardening estimated using extended analysis of blanking models. > The analysis methodology validated for different heat treated 9Cr-1Mo steel. > Changes in tensile properties of steel correlated with microstructures.
International Nuclear Information System (INIS)
Lee, Song In; Baek, Seoung Se; Kwon, Il Hyun; Yu, Hyo Sun
2002-01-01
A basic research was performed to ensure the usefulness of Small Punch-creep(SP-creep) test for residual life evaluation of heat resistant components effectively. This paper presents analytical results of initial stress and strain distributions in SP specimen caused by constant loading for SP-creep test and its experimental correlations with uniaxial creep(Ten-creep) test on 9CrlMoVNb steel. It was shown that the initial maximum equivalent stress, σ eq · max from FE analysis was correlated with steady-state equivalent creep strain rate, ε qf-ss , rupture time, t r , activation energy, Q and Larson-Miller parameter, LMP during SP-creep deformation. The simple correlation laws, σ SP - σ TEN , P SP -σ TEN and Q SP -Q TEN adopted to established a quantitative correlation between SP-creep and Ten-creep test data. Especially, the activation energy obtained from SP-creep test is linearly related to that from Ten-creep test at 650 deg. C as follows : Q SP-P =1.37 Q TEN , Q SP-σ =1.53 Q TEN
Microstructure and Tensile-Shear Properties of Resistance Spot-Welded Medium Mn Steel
Directory of Open Access Journals (Sweden)
Qiang Jia
2018-01-01
Full Text Available The medium Mn steels are gaining increasing attention due to their excellent combination of mechanical properties and material cost. A cold-rolled 0.1C5Mn medium Mn steel with a ferrite matrix plus metastable austenite duplex microstructure was resistance spot-welded with various welding currents and times. The nugget size rose with the increase of heat input, but when the welding current exceeded the critical value, the tensile-shear load increased slowly and became unstable due to metal expulsion. The fusion zone exhibited a lath martensite microstructure, and the heat-affected zone was composed of a ferrite/martensite matrix with retained austenite. The volume fraction of retained austenite decreased gradually from the base metal to the fusion zone, while the microhardness presented a reverse varying trend. Interfacial failure occurred along the interface of the steel sheets with lower loading capacity. Sufficient heat input along with serious expulsion brought about high stress concentration around the weld nugget, and the joint failed in partial interfacial mode. Pull-out failure was absent in this study.
Energy Technology Data Exchange (ETDEWEB)
Kumar, Pradeep [Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094 (India); Dutta, B.K., E-mail: bijon.dutta@gmail.com [Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094 (India); Chattopadhyay, J. [Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094 (India); Reactor Safety Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)
2017-04-01
The miniaturized specimens are used to determine mechanical properties of the materials, such as yield stress, ultimate stress, fracture toughness etc. Use of such specimens is essential whenever limited quantity of material is available for testing, such as aged/irradiated materials. The miniaturized small punch test (SPT) is a technique which is widely used to determine change in mechanical properties of the materials. Various empirical correlations are proposed in the literature to determine the value of fracture toughness (J{sub IC}) using this technique. bi-axial fracture strain is determined using SPT tests. This parameter is then used to determine J{sub IC} using available empirical correlations. The correlations between J{sub IC} and biaxial fracture strain quoted in the literature are based on experimental data acquired for large number of materials. There are number of such correlations available in the literature, which are generally not in agreement with each other. In the present work, an attempt has been made to determine the correlation between biaxial fracture strain (ε{sub qf}) and crack initiation toughness (J{sub i}) numerically. About one hundred materials are digitally generated by varying yield stress, ultimate stress, hardening coefficient and Gurson parameters. Such set of each material is then used to analyze a SPT specimen and a standard TPB specimen. Analysis of SPT specimen generated biaxial fracture strain (ε{sub qf}) and analysis of TPB specimen generated value of J{sub i}. A graph is then plotted between these two parameters for all the digitally generated materials. The best fit straight line determines the correlation. It has been also observed that it is possible to have variation in J{sub i} for the same value of biaxial fracture strain (ε{sub qf}) within a limit. Such variation in the value of J{sub i} has been also ascertained using the graph. Experimental SPT data acquired earlier for three materials were then used to get J
Those card are printed with minimal layout aids for the formatting of FORTRAN programs, plus extra guidelines every ten columns suggesting a generic tabular data layout. A punch card is a piece of stiff paper that can be used to contain digital information represented by the presence or absence of holes in predefined positions. Punched cards were used for specialized unit record machines, organized into semiautomatic data processing systems, used punched cards for data input, output, and storage. Furthermore many new digital computers started to used punched cards.
Physicists coded and recorded their programs through series of holes on punch paper tape or on punched cards. It was popular in the 1970s due to its high throughput speed and low cost, paper tape was one of the original data storage methods for computers. Information was encoded in the distinct pattern of holes punched in the paper; the paper itself was oiled to facilitate being run through the reading mechanism and to prevent tears due to brittleness. Though the paper was cheap, it had low storage capacity (only a few dozen kilobytes per roll) and the machinery involved in punching the holes was quite expensive. Higher capacity alternatives, such as magnetic tape, has get developped.
NCDC Punched Card Reference Manuals
National Oceanic and Atmospheric Administration, Department of Commerce — Documentation for using and reading punched cards kept at the National Weather Records Center (NWRC, previous name for NCDC and NCEI). Many of these punched card...
Small Punch Test Techniques for Irradiated Materials in Hot Cell
International Nuclear Information System (INIS)
Kim, Do Sik; Ahn, S. B.; Oh, W. H.; Yoo, B. O.; Choo, Y. S.
2006-06-01
Detailed procedures of the small punch test including the apparatus, the definition of small punch-related parameters, and the interpretation of results were presented. The testing machine should have a capability of the compressive loading and unloading at a given deflection level. The small punch specimen holder consists of an upper and lower die and clamping screws. The clamped specimen is deformed by using ball or spherical head punch. Two type of specimens with a circular and a square shape were used. The irradiated small punch specimen is made from the undamaged portion of the broken CVN bars or prepared by the irradiation of the specimen fabricated from the fresh materials. The heating and cooling devices should have the capability of the temperature control within ±2 .deg. C for the target value during the test. Based on the load-deflection data obtained from the small punch test. the empirical correlation between the small punch related parameters and a tensile properties such as 0.2% yield strength and ultimate tensile strength, fracture toughness, ductile-brittle transition temperature and creep properties determined from the standard test method is established and used to evaluate the mechanical properties of an irradiated materials. In addition, from the quantitative fractographic assessment of small punch test specimens, the relationship between the small punch energy and the quantity of ductile crack growth is obtained. Analytical formulations demonstrated good agreement with experimental load-deflection curves
Paul, Shubhajit; Taylor, Lisa J; Murphy, Brendan; Krzyzaniak, Joseph F; Dawson, Neil; Mullarney, Matthew P; Meenan, Paul; Sun, Changquan Calvin
2017-04-15
Punch sticking is a frequently occurring problem that challenges successful tablet manufacturing. A mechanistic understanding of the punch sticking phenomenon facilitates the design of effective strategies to solve punch sticking problems of a drug. The first step in this effort is to identify process parameters and particle properties that can profoundly affect sticking performance. This work was aimed at elucidating the key material properties and compaction parameters that influence punch sticking by statistically analyzing punch sticking data of 24 chemically diverse compounds obtained using a set of tooling with removable upper punch tip. Partial least square (PLS) analysis of the data revealed that particle surface area and tablet tensile strength are the most significant factors attributed to punch sticking. Die-wall pressure, ejection force, and take-off force also correlate with sticking, but to a lesser extent. Copyright © 2017 Elsevier B.V. All rights reserved.
Meniscal shear stress for punching.
Tuijthof, Gabrielle J M; Meulman, Hubert N; Herder, Just L; van Dijk, C Niek
2009-01-01
Experimental determination of the shear stress for punching meniscal tissue. Meniscectomy (surgical treatment of a lesion of one of the menisci) is the most frequently performed arthroscopic procedure. The performance of a meniscectomy is not optimal with the currently available instruments. To design new instruments, the punching force of meniscal tissue is an important parameter. Quantitative data are unavailable. The meniscal punching process was simulated by pushing a rod through meniscal tissue at constant speed. Three punching rods were tested: a solid rod of Oslash; 3.00 mm, and two hollow tubes (Oslash; 3.00-2.60 mm) with sharpened cutting edges of 0.15 mm and 0.125 mm thick, respectively. Nineteen menisci acquired from 10 human cadaveric knee joints were punched (30 tests). The force and displacement were recorded from which the maximum shear stress was determined (average added with three times the standard deviation). The maximum shear stress for the solid rod was determined at 10.2 N/mm2. This rod required a significantly lower punch force in comparison with the hollow tube having a 0.15 mm cutting edge (plt;0.01). The maximum shear stress for punching can be applied to design instruments, and virtual reality training environments. This type of experiment is suitable to form a database with material properties of human tissue similar to databases for the manufacturing industry.
Pilewska, Wiesława; Buśko, Krzysztof; Nikolaidis, Pantelis Theodoros
2017-11-01
The main aim of the study was to design a new system to measure punching forces in boxers. In addition, the study examined whether there were any relationship between force of punches and power of jump. A total of 9 boxers (age: 17.5±1.2 years, body height: 174.1±8.1 cm, body mass: 73.9±11.8 kg) participated in the study. The punching bag was equipped with acceleration transducers and gyroscopes embedded in a cylinder covered with a layer to absorb shock as well as a set of colour signal diodes. Value of the punching bag's acceleration was used for calculating: strike force; the punching location on the bag; and time of a strike. The relative error of force calculation was 3%; the relative error in acceleration measurement was less than 1%. The maximal straight of rear and lead punching forces were 1702.4±497.8 N and 1262.0±417.7 N in boxers, respectively. Strong correlations were found between the punching force and power of lower limbs developed for the ACMJ, CMJ and SPJ jump. Height of rise of the body mass centre and punching force correlated insignificantly. Based on these findings, it was concluded that the modified punching bag is a good diagnostic tool for combat sports. The measurement of power during the jump may be a good diagnostic test in boxers.
21 CFR 882.4750 - Skull punch.
2010-04-01
... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Skull punch. 882.4750 Section 882.4750 Food and... NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4750 Skull punch. (a) Identification. A skull punch is a device used to punch holes through a patient's skull to allow fixation of cranioplasty plates or...
NCDC Punched Card Inventory - 1950s
National Oceanic and Atmospheric Administration, Department of Commerce — Index of foreign weather data available on punched cards held at the Joint Punched Card Library in Asheville NC, produced in the late 1950s, and also station/data...
Lubricant test for punching and blanking
DEFF Research Database (Denmark)
Olsson, David Dam; Bay, Niels; Andreasen, Jan Lasson
2003-01-01
Punching/blanking is one of the tribologically wise most severe metal forming processes.Insu $cient lubrication leads to heavy pick-up of work piece material on the punch stem,bad tolerances and eventual breakdown of the punch due to excessive backstroke force,especially in case of tribologically...... of alternative lubricants the present paper describes a new lubricant test for punching....
Shear punch and microhardness tests for strength and ductility measurements
International Nuclear Information System (INIS)
Lucas, G.E.; Odette, G.R.; Sheckherd, J.W.
1983-01-01
In response to the requirements of the fusion reactor materials development program for small-scale mechanical property tests, two techniques have been developed, namely ball microhardness and shear punch tests. The ball microhardness test is based on the repeated measurement at increasing loads of the chordal diameter of an impression made by a spherical penetrator. A correlation has been developed to predict the constitutive relation of the test material from these data. In addition, the indentation pile-up geometry can be analyzed to provide information on the homogeneity of plastic flow in the test material. The shear punch test complements the microhardness test. It is based on blanking a circular disk from a fixed sheet metal specimen. The test is instrumented to provide punch load-displacement data, and these data can be used to determine flow properties of the test material such as yield stress, ultimate tensile strength, work-hardening exponent, and reduction of area
Studies of lubricants and punch design in punching of stainless steel
DEFF Research Database (Denmark)
Olsson, David Dam; Bay, Niels; Andreasen, Jan Lasson
2004-01-01
Environmentally hazardous lubricants such as chlorinated paraffin oils are often applied in punching and blanking operations especially involving stainless steel workpiece materials. This is due to the fact that punching and blanking are among the tribologically most difficult forming operations...
Configurational phases in elastic foams under lengthscale-free punching
Sabuwala, Tapan; Dai, Xiangyu; Gioia, Gustavo
2016-08-01
We carry out experiments with brick-like specimens of elastic open-cell (EOC) foams of three relative densities. Individual specimens may be "tall" (height = width = depth) or "short" (2 height = width = depth). We place each specimen on a supporting plate and use a lengthscale-free (wedge-shaped or conical) punch to apply forces downward along the specimen's height. Regardless of the type of specimen, the force-penetration curves remain linear, for the wedge-shaped punch, or quadratic, for the conical punch, up to a sizable penetration commensurate with the smallest lengthscale of the specimen. After that there is an abrupt, all-but-discontinuous change in stiffness: if the specimen is tall, the stiffness drops; if the specimen is short, the stiffness shoots up. To analyze these curious experimental results, we posit that EOC foams can be found in either of two configurational phases, here termed the low-strain phase and the high-strain phase, which share a two-dimensional interface (a surface of strain discontinuity). The analysis may be outlined as follows. In the first part of an experiment, there obtains a "similarity regime" in which the penetration of the punch and the radius of the interface are the only prevailing lengthscales (because the punch is lengthscale free). In this case, it is possible to show that the force-penetration curve must be linear, or quadratic, depending on whether the punch be wedge-shaped or conical, respectively. This prediction of the analysis is consistent with the experiments. In time, the similarity regime breaks down when the interface reaches one of the specimen's boundaries distal to the tip of the punch. If the specimen is tall, the soft, stress-free lateral boundary is reached first, and the stiffness must drop; if the specimen is short, the hard boundary in contact with the supporting plate is reached first, and the stiffness must shoot up. These predictions too are consistent with the experiments. To provide direct
Very heavy iron-punching concretes
International Nuclear Information System (INIS)
Dubois, F.
1966-01-01
The present report deals with all the heavy iron-punching concretes, metallic wastes produced by the transformation industry. After a detailed description of the physical properties of metallic aggregates, a classification of heavy mortars is given, into three main categories: steel-shot grouts d = 5,3 - 6; steel-shot grouts mixed with a mineral d = 3,7 - 4,2; injection heavy grouts d = 3,5 - 4. The following chapter describes iron-punching concretes the most used in the atomic industry: iron-punching concretes mixed with cast-iron - iron-punching concretes mixed with magnetite; iron-punching concretes mixed with barite; iron-punching concretes mixed with limonite; iron-punching concretes mixed with boron. The compositions of these concretes are given together with their physical and mechanical characteristics. Numerous diagrams make it possible to find rapidly the proportions of the constituents of these concretes as a function of the required density. Technical advice and specifications are given in an appendix together with a bibliography of these heavy concretes. (author) [fr
Small punch test evaluation methods for material characterisation
Energy Technology Data Exchange (ETDEWEB)
Janča, Adam, E-mail: adam.janca@fjfi.cvut.cz; Siegl, Jan, E-mail: jan.siegl@fjfi.cvut.cz; Haušild, Petr, E-mail: petr.hausild@fjfi.cvut.cz
2016-12-01
The Small Punch Test (SPT) is one of the most widespread mechanical testing methods using miniaturized specimens. The paper presented deals with the time independent SPT, in which a flat specimen is bent by means of a (hemi)spherical punch moving at a constant velocity. The main goal is to relate the measured data to deformation processes taking place during specimen loading. Understanding of such relations is crucial for characterizing a material using any non-standardized experimental procedure. Using enhanced instrumentation, not only traditional load-displacement or load-deflection curves could be obtained, but also specimen thinning could be continuously measured and evaluated. Five alloys having a broad range of mechanical properties were tested. The results obtained were evaluated using both traditional and newly proposed methods and they were correlated with results of the conventional tensile test. The methods proposed seem to lead to a universal correlation between SPT results and tensile characteristics. - Highlights: • The newly proposed methodology significantly improved results of SPT. • Plastic deformation starts inside the specimen from the very beginning of loading. • Specimen thinning = punch displacement−specimen deflection. • Material response to loading is well illustrated by the novel load-thinning curve.
Recent progress in shear punch testing
International Nuclear Information System (INIS)
Hamilton, M.L.; Toloczko, M.B.; Lucas, G.E.
1994-09-01
The shear punch test was developed in response to the needs of the materials development community for small-scale mechanical properties tests. Such tests will be of great importance when a fusion neutron simulation device is built, since such a device is expected to have a limited irradiation volume. The shear punch test blanks a circular disk from a fixed sheet metal specimen, specifically a TEM disk. Load-displacement data generated during the test can be related to uniaxial tensile properties such as yield and ultimate strength. Shear punch and tensile tests were performed at room temperature on a number of unirradiated aluminum, copper, vanadium, and stainless steel alloys and on several irradiated aluminum alloys. Recent results discussed here suggest that the relationship between shear punch strength and tensile strength varies with alloy class, although the relationship determined for the unirradiated condition remains valid for the irradiated aluminum alloys
Single maximal versus combination punch kinematics.
Piorkowski, Barry A; Lees, Adrian; Barton, Gabor J
2011-03-01
The aim of this study was to determine the influence of punch type (Jab, Cross, Lead Hook and Reverse Hook) and punch modality (Single maximal, 'In-synch' and 'Out of synch' combination) on punch speed and delivery time. Ten competition-standard volunteers performed punches with markers placed on their anatomical landmarks for 3D motion capture with an eight-camera optoelectronic system. Speed and duration between key moments were computed. There were significant differences in contact speed between punch types (F(2,18,84.87) = 105.76, p = 0.001) with Lead and Reverse Hooks developing greater speed than Jab and Cross. There were significant differences in contact speed between punch modalities (F(2,64,102.87) = 23.52, p = 0.001) with the Single maximal (M+/- SD: 9.26 +/- 2.09 m/s) higher than 'Out of synch' (7.49 +/- 2.32 m/s), 'In-synch' left (8.01 +/- 2.35 m/s) or right lead (7.97 +/- 2.53 m/s). Delivery times were significantly lower for Jab and Cross than Hook. Times were significantly lower 'In-synch' than a Single maximal or 'Out of synch' combination mode. It is concluded that a defender may have more evasion-time than previously reported. This research could be of use to performers and coaches when considering training preparations.
Punch Biopsy Results in Misdiagnosis of Pilomatrixoma
Directory of Open Access Journals (Sweden)
Metin Temel
2017-03-01
Full Text Available Punch biopsy results in misdiagnosis of clinically unsuspected giant pilomatrixoma located over the parotid gland. This study presents a case of pilomatrixoma that was misdiagnosed as a malignant epithelial tumor using punch biopsy. A 25-year-old male was admitted to our clinic for the evaluation of a mass measuring 7×8×8 cm located over the parotid gland. The patient had previously undergone punch biopsy at another clinic because of a lesion in the parotid gland. Punch biopsy revealed a malignant epithelial tumor. The patient underwent excisional biopsy at our clinic. After the biopsy, the residual skin defect was treated using full-thickness skin grafts. The facial nerve and parotid gland were preserved during the biopsy. Histopathological examination of the excisional biopsy material revealed pilomatrixoma. Punch biopsy may result in misdiagnosis of skin lesions in the parotid gland. A differential diagnosis for benign tumors such as pilomatrixoma is essential prior to an aggressive surgical intervention of the parotid gland.
Shear punch tests performed using a new low compliance test fixture
International Nuclear Information System (INIS)
Toloczko, M.B.; Kurtz, R.J.; Hasegawa, A.; Abe, K.
2002-01-01
Based on a recent finite element analysis (FEA) study performed on the shear punch test technique, it was suggested that compliance in a test frame and fixturing which is quite acceptable for uniaxial tensile tests, is much too large for shear punch tests. The FEA study suggested that this relatively large compliance was masking both the true yield point and the shape of the load versus displacement trace obtained in shear punch tests. The knowledge gained from the FEA study was used to design a new shear punch test fixture which more directly measures punch tip displacement. The design of this fixture, the traces obtained from this fixture, and the correlation between uniaxial yield stress and shear yield stress obtained using this fixture are presented here. In general, traces obtained from the new fixture contain much less compliance resulting in a trace shape which is more similar in appearance to a corresponding uniaxial tensile trace. Due to the more direct measurement of displacement, it was possible to measure yield stress at an offset shear strain in a manner analogous to yield stress measurement in a uniaxial tensile test. The correlation between shear yield and uniaxial yield was altered by this new yield measurement technique, but the new correlation was not as greatly improved as was suggested would occur from the FEA study
Energy Technology Data Exchange (ETDEWEB)
Nejadseyfi, Omid, E-mail: o.nejadseyfi@gmail.com [Advanced Materials and Nanotechnology Research Lab, Department of Mechanical Engineering, K.N. Toosi University of Technology, Tehran (Iran, Islamic Republic of); Shokuhfar, Ali [Advanced Materials and Nanotechnology Research Lab, Department of Mechanical Engineering, K.N. Toosi University of Technology, Tehran (Iran, Islamic Republic of); Sadeghi, Seyedali [Department of Mechanical Engineering, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of)
2016-01-10
The advantage of using a beveled-edge punch in equal-channel angular pressing is investigated. Lambda angle (λ), the clockwise angle between the theoretical shear plane and punch/billet interface, is used to demonstrate how the punch tip is inclined. Transmission electron microscope is used to assess the microstructure of the samples processed using a beveled-edge punch. In addition, tensile tests at elevated temperature are performed. The results show that using a beveled-edge punch (λ=90°) in the process leads to formation of uniform subgrain structure and increases the tensile ductility for the samples at elevated temperature. Additionally, finite element simulations are performed to study the correlation between measured properties and mechanism of material deformation by employing a beveled-edge punch. Numerical simulations confirm the irregular deformation in case of λ=0° and uniform strain distribution for λ=90°, which were the main reasons of variation in mechanical properties.
A solution for the narrow rectangular punch
Panek, C.F.; Kalker, J.J.
1977-01-01
This paper considers the problem of a rectangular flat ended punch acting on an elastic half-space. An approximate solution is generated through application of the elastic line integral equations. The results produced by this method are then compared with another approximate solution already
Damage modeling in Small Punch Test specimens
DEFF Research Database (Denmark)
Martínez Pañeda, Emilio; Cuesta, I.I.; Peñuelas, I.
2016-01-01
. Furthermore,Gurson-Tvergaard-Needleman model predictions from a top-down approach are employed to gain insightinto the mechanisms governing crack initiation and subsequent propagation in small punch experiments.An accurate assessment of micromechanical toughness parameters from the SPT...
Optimization of fruit punch using mixture design.
Kumar, S Bharath; Ravi, R; Saraswathi, G
2010-01-01
A highly acceptable dehydrated fruit punch was developed with selected fruits, namely lemon, orange, and mango, using a mixture design and optimization technique. The fruit juices were freeze dried, powdered, and used in the reconstitution studies. Fruit punches were prepared according to the experimental design combinations (total 10) based on a mixture design and then subjected to sensory evaluation for acceptability. Response surfaces of sensory attributes were also generated as a function of fruit juices. Analysis of data revealed that the fruit punch prepared using 66% of mango, 33% of orange, and 1% of lemon had highly desirable sensory scores for color (6.00), body (5.92), sweetness (5.68), and pleasantness (5.94). The aroma pattern of individual as well as combinations of fruit juices were also analyzed by electronic nose. The electronic nose could discriminate the aroma patterns of individual as well as fruit juice combinations by mixture design. The results provide information on the sensory quality of best fruit punch formulations liked by the consumer panel based on lemon, orange, and mango.
International Nuclear Information System (INIS)
Campitelli, E.; Spatig, P.; Bertsch, J.
2007-01-01
Full text of publication follows: Over the years, the small ball punch test technique has been used to evaluate conventional tensile properties of a variety of materials. The development and use of this type of small specimen techniques is indispensable for an efficient use of the limited irradiation volume of the future fusion material intense neutron source. Up to now, empirical correlations between features of the load-displacement curves of the ball punch test and the mechanical properties, such as the yield stress or the ultimate tensile stress, are established on materials in the unirradiated condition. These correlations are believed to be applicable to irradiated materials and they have been very often used to estimate the irradiation hardening. However, it is well known that the overall constitutive behavior of the materials is generally affected by neutron irradiation. Therefore, there is a need to quantify the effect of the constitutive behavior on the correlations. In this paper, we employ a 3D non-linear finite element model for the ball punch test to address these effects of the irradiation-induced changes on the ball punch test curve. We apply first the model on the tempered martensitic steel EUROFER97 in the unirradiated condition with variations in the post-yield behavior, either in the low strain domain ( 10%). The effects on the ball punch test load deflection curve are outlined. Second, we study the effects of the irradiation hardening on the same constitutive behaviors as those used for the unirradiated condition. We show that that the usual correlations must be considered with great care on irradiated materials since strong variation on the strain-hardening may lead to erroneous estimation of the irradiation hardening. We also propose a novel approach to calibrate the yield stress to features of the ball punch test curve that decreases the uncertainty related to the post-yield behavior and that, as a consequence, makes the technique more
Novel uses of skin biopsy punches in dermatosurgery
Directory of Open Access Journals (Sweden)
Deepak S Hurkudli
2015-01-01
Full Text Available The skin punch or surgical punch is an instrument which is used almost exclusively by dermatologists. It is a circular hollow blade attached to a pencil-like handle ranging in size from 0.5 to 10 mm. It is available as a disposable, reusable, and automated instrument. The punch can be used as a diagnostic, therapeutic, and cosmetic tool in dermatology. We have used punch as a diagnostic, therapeutic, and cosmetic tool in our dermatosurgery practice in our hospital. Various original research articles, text book publications, and review articles were studied and compiled. Techniques used by various authors and our own experiences with punch have been described. This article aims at providing the novel usefulness of skin biopsy punch in dermatology as the basic punch surgery is quick and easy to learn. Complications such as bleeding and infection are minimal.
Small Punch Tests applied to the nuclear industry
International Nuclear Information System (INIS)
Moreno, M.; Gongora, P.; Bertolino, G; Yawny, A.
2012-01-01
The interest on miniaturized specimen techniques for the characterization of the mechanical behavior of materials was strongly motivated in the early eighties by the different programs associated with the development of fusion reactor technology. The importance of such developments is obvious in the case of the nuclear industry where the limited space available, the presence of fluence gradients in large specimens, the concern about gamma heating and dose to personnel in post-irradiation testing have all been motivations for reducing specimen size. Testing of miniature specimen includes a wide spectrum of techniques such as tensile, instrumented micro-hardness, small punch, bend, fracture, impact and fatigue. Small Punch Testing (SPT) techniques use a spherical penetrator which deforms to failure a miniature disc shaped flat specimen (typically, 3-10 mm in diameter and 0.25-0.50 mm in thickness) supported on its outer rim. Analysis of load-displacement data recorded along the test is performed for the determination of the property of interest. The present work focuses on the characterization of the elastoplastic response of pure Al, ADN 420 structural steel and AISI 304L using SPT and its correlation with the associated standard uniaxial testing behavior. In addition, the sensitivity of the technique to the specific material under study and to different experimental parameters, i.e. specimen diameter and thickness, clearance or clamping force and friction between disc and dies have been assessed both experimentally and by performing simulations using the finite element method (author)
Voss, B. M.; Pereira, M. P.; Rolfe, B. F.; Doolan, M. C.
2017-09-01
The growth in use of Advanced High Strength Steels in the automotive industry for light-weighting and safety has increased the rates of tool wear in sheet metal stamping. This is an issue that adds significant costs to production in terms of manual inspection and part refinishing. To reduce these costs, a tool condition monitoring system is required and a firm understanding of process signal variation must form the foundation for any such monitoring system. Punch force is a stamping process signal that is widely collected by industrial presses and has been linked closely to part quality and tool condition, making it an ideal candidate as a tool condition monitoring signal. In this preliminary investigation, the variation of punch force due to different lubrication conditions and progressive wear are examined. Linking specific punch force signature changes to developing lubrication and wear events is valuable for die wear and stamping condition monitoring. A series of semi-industrial channel forming trials were conducted under different lubrication regimes and progressive die wear. Punch force signatures were captured for each part and Principal Component Analysis (PCA) was applied to determine the key Principal Components of the signature data sets. These Principal Components were linked to the evolution of friction conditions over the course of the stroke for the different lubrication regimes and mechanism of galling wear. As a result, variation in punch force signatures were correlated to the current mechanism of wear dominant on the formed part; either abrasion or adhesion, and to changes in lubrication mechanism. The outcomes of this study provide important insights into punch force signature variation, that will provide a foundation for future work into the development of die wear and lubrication monitoring systems for sheet metal stamping.
Energy Technology Data Exchange (ETDEWEB)
Tettamanti, S. [CISE SpA, Milan (Italy); Crudeli, R. [ENEL SpA, Milan (Italy)
1998-12-31
CISE and ENEL are involved for years in a miniaturization creep methodology project to obtain similar non-destructive test with the same standard creep test reliability. The goal can be reached with `Small punch creep test` that collect all the requested characteristics; quasi nondestructive disk specimens extracted both on external or internal side of components, than accurately machined and tested on little and cheap apparatus. CISE has developed complete creep small punch procedure that involved peculiar test facility and correlation`s law comparable with the more diffused isostress methodology for residual life evaluation on ex-serviced high temperature plant components. The aim of this work is to obtain a simple and immediately applicable relationship useful for plant maintenance managing. More added work is need to validate the Small Punch methodology and for relationship calibration on most diffusion high temperature structural materials. First obtained results on a comparative work on ASTM A355 P12 ex-serviced pipe material are presented joint with a description of the Small Punch apparatus realized in CISE. (orig.) 6 refs.
Energy Technology Data Exchange (ETDEWEB)
Tettamanti, S [CISE SpA, Milan (Italy); Crudeli, R [ENEL SpA, Milan (Italy)
1999-12-31
CISE and ENEL are involved for years in a miniaturization creep methodology project to obtain similar non-destructive test with the same standard creep test reliability. The goal can be reached with `Small punch creep test` that collect all the requested characteristics; quasi nondestructive disk specimens extracted both on external or internal side of components, than accurately machined and tested on little and cheap apparatus. CISE has developed complete creep small punch procedure that involved peculiar test facility and correlation`s law comparable with the more diffused isostress methodology for residual life evaluation on ex-serviced high temperature plant components. The aim of this work is to obtain a simple and immediately applicable relationship useful for plant maintenance managing. More added work is need to validate the Small Punch methodology and for relationship calibration on most diffusion high temperature structural materials. First obtained results on a comparative work on ASTM A355 P12 ex-serviced pipe material are presented joint with a description of the Small Punch apparatus realized in CISE. (orig.) 6 refs.
HOW BOXERS DECIDE TO PUNCH A TARGET: EMERGENT BEHAVIOUR IN NONLINEAR DYNAMICAL MOVEMENT SYSTEMS
Directory of Open Access Journals (Sweden)
Robert Hristovski
2006-07-01
Full Text Available Previous research has shown how dynamical systems theory provides a relevant framework for investigating decision-making behavior in sport. The aim of this study was to adopt concepts and tools from nonlinear dynamics in examining effects of boxer-target distance and perceived punching efficiency on emergent decision-making during a typical practice task in boxing. Results revealed the existence of critical values of scaled distances between boxers and targets for first time appearance and disappearance of a diverse range of boxing actions including jabs, hooks and uppercuts. Reasons for the diversity of actions were twofold: i abrupt (qualitative changes in the number of the possible punches, i.e. motor solutions to the hitting task; and ii, fine modification of the probabilities of selecting specific striking patterns. Boxers were able to exploit the emerging perception of strikeability, leading to a changing diversity of selected actions and a cascade of abrupt changes in the perceptual-motor work space of the task. Perceived efficiency of a punching action by the participants also changed as a function of the scaled distance to a target and was correlated with the probability of occurrence of specific boxing actions. Accordingly, scaled distance-dependent perceived efficiency seems an important perceptual constraint in the training task of punching a heavy bag in boxers
Analysis of Pick-Up Development in Punching
DEFF Research Database (Denmark)
Olsson, David Dam; Bay, Niels; Andreasen, Jan Lasson
2002-01-01
The development of pick-up of work piece material on the punch surface with increasing number of strokes during punching of stainless steel sheet is investigated applying Scanning Electron Microscopy (SEM), 3D roughness mapping and measurements of the backstroke force. It is found that pick...
Development of lubricant test for punching and blanking
DEFF Research Database (Denmark)
Olsson, David Dam
2001-01-01
The background for development of new lubricants Requirements to lubricant test for punching Methods of evaluating lubricants Test equipment developed at DTU Conclusion.......The background for development of new lubricants Requirements to lubricant test for punching Methods of evaluating lubricants Test equipment developed at DTU Conclusion....
Applying a punch with microridges in multistage deep drawing processes.
Lin, Bor-Tsuen; Yang, Cheng-Yu
2016-01-01
The developers of high aspect ratio components aim to minimize the processing stages in deep drawing processes. This study elucidates the application of microridge punches in multistage deep drawing processes. A microridge punch improves drawing performance, thereby reducing the number of stages required in deep forming processes. As an example, the original eight-stage deep forming process for a copper cylindrical cup with a high aspect ratio was analyzed by finite element simulation. Microridge punch designs were introduced in Stages 4 and 7 to replace the original punches. In addition, Stages 3 and 6 were eliminated. Finally, these changes were verified through experiments. The results showed that the microridge punches reduced the number of deep drawing stages yielding similar thickness difference percentages. Further, the numerical and experimental results demonstrated good consistency in the thickness distribution.
Research on the Visual Processing System of the Punch Press
Directory of Open Access Journals (Sweden)
Sun Xuan
2016-01-01
Full Text Available Most of raw materials of small hardware processing for plate scraps, and it’s realized through the manual operation of ordinary punch, which way has the low production efficiency and the high labor intensity. In order to improve the automation level of production, developing and designing of a visual processing system for punch press manipulator which based on the MFC tools of Visual Studio software platform. Through the image acquisition and image processing, get the information about the board to be processed, such as shape, length, the center of gravity position and pose, and providing relevant parameters for positioning gripping and placing into the punch table positioning of the feeding manipulator and automatic programming of punching machine, so as to realize the automatic operation about press feeding and processing.
Countering Stryker’s Punch: Algorithmically Filling the Black Hole
Michael J. Bennett
2017-01-01
Two current digital image editing programs are examined in the context of filling in missing visual image data from hole-punched United States Farm Security Administration (FSA) negatives. Specifically, Photoshop's Content-Aware Fill feature and GIMP's Resynthesizer plugin are evaluated and contrasted against comparable images. A possible automated workflow geared towards large scale editing of similarly hole-punched negatives is also explored. Finally, potential future research based upon th...
Directory of Open Access Journals (Sweden)
Takashi Osamura
2017-09-01
Full Text Available We previously determined “Tableting properties” by using a multi-functional single-punch tablet press (GTP-1. We proposed plotting “Compactability” on the x-axis against “Manufacturability” on the y-axis to allow visual evaluation of “Tableting properties”. Various types of tableting failure occur in commercial drug production and are influenced by the amount of lubricant used and the shape of the punch. We used the GTP-1 to measure “Tableting properties” with different amounts of lubricant and compared the results with those of tableting on a commercial rotary tableting machine. Tablets compressed with a small amount of lubricant showed bad “Manufacturability”, leading to sticking of powder on punches. We also tested various punch shapes. The GTP-1 correctly predicted the actual tableting results for all punch shapes. With punches that were more likely to cause tableting failure, our system predicted the effects of lubricant quantity in the tablet formulation and the occurrence of sticking in the rotary tableting machine.
Moment Capacity of Timber Reinforced with Punched Metal Plate Fasteners
DEFF Research Database (Denmark)
Nielsen, Jacob; Ellegaard, Peter
When designing timber trusses it is often found that the cross section controlling the dimensions of the top chord is located at a joint with a moment peak. However, the timber volume affected by the moment peak is rather limited and by embedding a punched metal plate in this area a reinforcement...... of the section is obtained, resulting in a more economic truss design. In order to develop design methods for sections with plate reinforcement, bending tests have been made. The timber is Swedish spruce of strength class K-18(S8) and K-24(S10) with a thickness of 45 mm. The punched metal plate is from Gang...
Didin Zakaria Lubis; Ichsan Ristiawan
2017-01-01
This study aims to identify the influences between clearance and punch velocity on the part edge quality of blanked parts. Experiments have been conducted using material copper, punch-die clearance and punch velocity variations. In order to determine the reachable punch-die clearance and punch velocity required for blanking. The quality of the part-edge characteristics shows that higher punch velocity and decreases clearance value can improve the part-edge quality, resulting in smaller burr h...
Recent developments in small punch testing: Applications at elevated temperatures
Czech Academy of Sciences Publication Activity Database
Dymáček, Petr
2016-01-01
Roč. 86, DEC (2016), s. 25-33 ISSN 0167-8442 R&D Projects: GA MŠk(CZ) LQ1601 Institutional support: RVO:68081723 Keywords : Small punch test * Creep rupture * Stress relaxation Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 2.659, year: 2016
A Semiotics of Cartoons in Two Nigerian Newspapers: The Punch ...
African Journals Online (AJOL)
The paper explores the semiotics of cartoons using selected samples from The punch and The Guardian, newspapers based in Nigeria. It seeks to bridge the gap between semiotics and the act of cartooning. It also attempts to show the relationship between the cartoons and the semiotic resources employed. It analyses how ...
Analysis of the Strength on the Rotor Punching Sheet of Nuclear Reactor Cooling Medium Driving Motor
Directory of Open Access Journals (Sweden)
GE Bao-jun
2017-02-01
Full Text Available A strong stress is withstood by the rotor punching sheet during the running of nuclear reactor cooling medium driving motor. In order to study the strength on the rotor punching sheet and the influential factor of its stress，the rotor of driving motor was the research object, the three-dimensional rotor model of driving motor is established by the finite element method to obtain the Mires equivalent stress nephogram and check the rotor’s strength with setting parameters and constraints. According to different rotor speeds，the different average temperatures of rotor punching sheet and shaft and the different static magnitude of interference between rotor punching sheet and shaft，the research about how the contact pressure of matching surface between rotor punching sheet and shaft and the Mires equivalent stress are impacted is carried on. The results show that the maximum Miser equivalent stress value of rotor punching sheet emerges on the axial vents，the stress value is beyond the tensile limit of the materialand. The greater the static magnitude of interference and the smaller temperature difference of rotor punching sheet and shaft lead to the greater interface compressive stress of rotor punching sheet and shaft and the greater maximum Mires equivalent stress value of rotor punching sheet. The higher the rotor speed lead to the smaller interface compressive stress of rotor punching sheet and shaft and the greater equivalent stress value of rotor punching sheet.
Characterization of Rubbers from Spherical Punch - Plate Indentation Tests
Directory of Open Access Journals (Sweden)
Florina Carmen Ciornei
2016-12-01
Full Text Available Rubber plates with different compositions and hardness were tested by continuous indentation, using a spherical punch and hysteretic phenomenon was evidenced. The experimental data interpolation with polynomial functions is accurate and permits estimation of the lost work during loading cycles. The interpolation by power law functions is more convenient by using less parameters and having a form accepted in literature. From the rubbers tested, two were considered to present good damping properties.
International Nuclear Information System (INIS)
Eto, Motokuni; Suzuki, Masahide; Nishiyama, Yutaka; Fukaya, Kiyoshi; Jitsukawa, Shiro; Misawa, Toshihei
1993-01-01
To examine the effectiveness of the small punch test for evaluating strength and toughness of irradiated ferritic steels, detailed procedures are described aiming at standardization of the test. The statistical approach to analysis of the SP energy as a function of temperature for evaluation of DBTT was also reviewed. The method was then applied to neutron-irradiated ferritic steels, which included F-82, F-82H, HT-9, and 2 1/4 Cr-1Mo steel. Fluence and irradiation temperatures ranged from 2 to 12 x 10 23 n/m 2 (E ≥ 1 MeV) and from 573 to 673 K, respectively. Comparison of parameters obtained from the small punch test with the properties measured by the conventional method indicated that: (a) the 0.2% offset stress and the ultimate tensile strength at room temperature can be correlated well with the parameters, P y /(t 0 ) 2 and P max /(t 0 ) 2 , respectively. Here, P y and P max are the loads corresponding to the yield and the maximum, and t 0 is the initial thickness of a specimen; (b) fracture toughness, J IC , can be evaluated using equivalent fracture strain, anti ε qf , and the previously established relationship between these values; and (c) DBTT measured by a Charpy test can be predicted from the results of temperature dependence of SP energy determined from the area under the load-deflection curve using a statistical analysis based on a Weibull distribution
Measurement of tensile and fracture toughness properties using small punch test
International Nuclear Information System (INIS)
Chatterjee, S.; Shah Priti Kotak
2005-05-01
Small punch test wu carried out at room temperature on five different steels using 10 mm by 10 mm specimens of 0.4 mm thickness in a univesal testing machine. The tensile and fracture toughness properties of the five steels obtained from small punch test were compared with those obtained from the standard test method. The results (except in one steel) show that the tensile properties obtained from small punch test are in close proximity to those obtained ftom uni-axial tension test. The results also show that fracture toughness (Jic) properties obtained ftom small punch test are within ±20% of the corresponding values obtained using standard test procedures. (author)
Bruzas, Vidas; Kamandulis, Sigitas; Venckunas, Tomas; Snieckus, Audrius; Mockus, Pranas
2018-03-01
During competition, a boxer must continue to deliver high-impact punches despite increasing fatigue. It is unclear whether the effects of plyometric training using external weights are transferred to sport-specific movements such as punching. The aim of the study was to investigate the effects of a 4-week cycle of plyometric training with external weights on punching ability. The study involved eight male amateur boxers aged 22.3±2.5 years with at least 7 years of competitive experience. They performed 12 plyometric training sessions, each comprising eight exercises of various muscle groups performed at maximum movement velocity. Six drills were performed with external weights, and two drills were performed using the body weight as resistance. All exercises required coordination. The punching ability was tested at baseline and after the 4 weeks of training using the Kiktest-100 boxing bag. The force of single punches and the frequency of punches within a series did not change from before to after the 4 weeks, except for increased power in the rear-hand low punch (Pplyometric training with external weights did not change the maximum punching power or movement frequency significantly, but had a beneficial effect on punching power endurance in boxers.
FORTRAN text correction with the CDC-1604-A console typewriter during reading a punched card program
International Nuclear Information System (INIS)
Kotorobaj, F.; Ruzhichka, Ya.; Stolyarskij, Yu.V.
1977-01-01
The paper describes FORTRAN text correction with the CDC 1604-A console typewriter during reading a punched card program. This method gives one more possibility of FORTRAN program correction during program's input to the CDC 1604-A computer. This essentially reduced the time necessary for punched card correction with other methods. Possibility of inputting desired number of punched cards one after another allows one writing small FORTRAN programs to computer core storage with simultaneous punching of the cards. The correction program has been written to the CDC 1604 COOP monitor
Huixia Liu; Jianwen Li; Zongbao Shen; Qing Qian; Hongfeng Zhang; Xiao Wang
2015-01-01
The aim of this paper is to fabricate micro-gears via laser shock punching with Spitlight 2000 Nd-YAG Laser, and to discuss effects of process parameters namely laser energy, soft punch properties and blank-holder on the quality of micro-gears deeply. Results show that dimensional accuracy is the best shocked at 1690 mJ. Tensile fracture instead of shear fracture is the main fracture mode under low laser energy. The soft punch might cause damage to punching quality when too high energy is emp...
Small punch creep test in a 316 austenitic stainless steel
Directory of Open Access Journals (Sweden)
Saucedo-Muñoz, Maribel L.
2015-03-01
Full Text Available The small punch creep test was applied to evaluate the creep behavior of a 316 type austenitic stainless steel at temperatures of 650, 675 and 700 °C. The small punch test was carried out using a creep tester with a specimen size of 10×10×0.3 mm at 650, 675 and 700 °C using loads from 199 to 512 N. The small punch creep curves show the three stages found in the creep curves of the conventional uniaxial test. The conventional creep relationships which involve parameters such as creep rate, stress, time to rupture and temperature were followed with the corresponding parameters of small punch creep test and they permitted to explain the creep behavior in this steel. The mechanism and activation energy of the deformation process were the grain boundary sliding and diffusion, respectively, during creep which caused the intergranular fracture in the tested specimens.El ensayo de termofluencia por indentación se utilizó para evaluar el comportamiento a la termofluencia en un acero inoxidable austenítico 316. Este ensayo se realizó en una máquina de indentación con muestras de 10×10×0,3 mm a temperaturas de 650, 675 y 700 °C con cargas de 199 a 512 N. Las curvas de termofluencia del ensayo mostraron las tres etapas características observadas en el ensayo convencional de tensión. Asimismo, las principales relaciones de termofluencia entre parámetros como velocidad de termofluencia, esfuerzo, tiempo de ruptura y temperatura se observaron en los parámetros correspondientes al ensayo de indentación, lo que permitió caracterizar el comportamiento de termofluencia en este acero. El mecanismo y la energía de activación del proceso de deformación en la termofluencia corresponden al deslizamiento de los límites de grano y la difusión a través de los mismos, respectivamente, lo cual causó la fractura intergranular en las muestras ensayadas.
Precision hole punching on composite fiber reinforced polymer panels
Abdullah, A. B.; Zain, M. S. M.; Chan, H. Y.; Samad, Z.
2017-12-01
Structural materials, such as composite panels, can only be assembled, and in most cases through the use of fasteners, which are fitted into the drilled holes. However, drilling is costly and time consuming, thus affecting productivity. This research aims to develop an alternative method to drilling. In this paper, the precision of the holes was measured and the effects of the die clearance to the areas around the holes were evaluated. Measurement and evaluation were performed based on the profile of the holes constructed using Alicona IFM, a 3D surface measurement technique. Results showed that punching is a potential alternative to drilling but still requires improvements.
Shear Punch Testing of BOR-60 Irradiated TEM Specimens
Energy Technology Data Exchange (ETDEWEB)
Saleh, Tarik A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Quintana, Matthew Estevan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Romero, Tobias J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2017-06-13
As a part of the project “High Fidelity Ion Beam Simulation of High Dose Neutron Irradiation” an Integrated Research Program (IRP) project from the U.S. Department of Energy, Nuclear Energy University Programs (NEUP), TEM geometry samples of ferritic cladding alloys, Ni based super alloys and model alloys were irradiated in the BOR-60 reactor to ~16 dpa at ~370°C and ~400°C. Samples were sent to Los Alamos National Laboratory and subjected to shear punch testing. This report presents the results from this testing.
Advanced Modelling of Trusses with Punched Metal Plate Fasteners
DEFF Research Database (Denmark)
Ellegaard, Peter; Nielsen, Jacob
Most of the finite element programs for design of timber trusses with punched metal fasteners are based on models using beam and fictitious elements. Different models have been used for different types of joints. Common problems for all the models are how to calculate the forces in the nail groups...... and the plates and furthermore, how big 'the deformations in the joints are. By developing an advanced model that includes all parts of the joint, i.e. plate, nail groups and contact it is possible to give a better description of the joint. An advanced model with these properties is presented. The advanced model...
Kadouch, D. J.; Leeflang, M. M.; Elshot, Y. S.; Longo, C.; Ulrich, M.; van der Wal, A. C.; Wolkerstorfer, A.; Bekkenk, M. W.; de Rie, M. A.
2017-01-01
BackgroundIn vivo reflectance confocal microscopy (RCM) is a promising non-invasive skin imaging technique that could facilitate early diagnosis of basal cell carcinoma (BCC) instead of routine punch biopsies. However, the clinical value and utility of RCM vs. a punch biopsy in diagnosing and
High-throughput sequencing of forensic genetic samples using punches of FTA cards with buccal swabs
DEFF Research Database (Denmark)
Kampmann, Marie-Louise; Buchard, Anders; Børsting, Claus
2016-01-01
Here, we demonstrate that punches from buccal swab samples preserved on FTA cards can be used for high-throughput DNA sequencing, also known as massively parallel sequencing (MPS). We typed 44 reference samples with the HID-Ion AmpliSeq Identity Panel using washed 1.2 mm punches from FTA cards...
Punch grafts to treat lower limb intractable sores
Directory of Open Access Journals (Sweden)
JÚLIO WILSON FERNANDES
Full Text Available ABSTRACT Lower limb recurrent ulcers, usually caused by prolonged decubitus, trauma, diabetes or burns, may not heal with conventional clinical or surgical treatment. Frequently, laminated skin grafts do not integrate with the recipient layer, and the only alternatives are neighbor microsurgical flaps. These have higher morbidity and create secondary defects, to be corrected with skin grafts, when fasciocutaneous or miocutaneous segments are removed for the treatment of the primary defect. We describe the non-conventional use of punch grafts in the treatment of lower limb ulcers, when conventional skin laminated graft failed, without the use of flaps. Since this is a very successful technique, its use should be considered as a valuable alternative for the treatment of recurrent lower limb ulcers. It is a simple and easy-learned technique that may be used by different surgeons, even in remote places without correct specialized hospital facilities.
Campbell, Ian W
2016-07-01
During the 1640s, the Irish Franciscan theologian John Punch taught his theology students in Rome that war against Protestants was made just by their religion alone. Jesuits like Luis de Molina identified the holy war tradition in which Punch stood as a Scotist one, and insisted that the Scotists had confused the natural and supernatural spheres. Among Irishmen, Punch was unusual. The main Irish Catholic revolutionary tradition employed Jesuit and Thomist theory. They argued that the Stuarts had lost the right to rule Ireland for natural reasons, not supernatural ones; because the Stuarts were tyrants, not because they were Protestants.
High-throughput sequencing of forensic genetic samples using punches of FTA cards with buccal swabs.
Kampmann, Marie-Louise; Buchard, Anders; Børsting, Claus; Morling, Niels
2016-01-01
Here, we demonstrate that punches from buccal swab samples preserved on FTA cards can be used for high-throughput DNA sequencing, also known as massively parallel sequencing (MPS). We typed 44 reference samples with the HID-Ion AmpliSeq Identity Panel using washed 1.2 mm punches from FTA cards with buccal swabs and compared the results with those obtained with DNA extracted using the EZ1 DNA Investigator Kit. Concordant profiles were obtained for all samples. Our protocol includes simple punch, wash, and PCR steps, reducing cost and hands-on time in the laboratory. Furthermore, it facilitates automation of DNA sequencing.
Directory of Open Access Journals (Sweden)
Didin Zakaria Lubis
2017-11-01
Full Text Available This study aims to identify the influences between clearance and punch velocity on the part edge quality of blanked parts. Experiments have been conducted using material copper, punch-die clearance and punch velocity variations. In order to determine the reachable punch-die clearance and punch velocity required for blanking. The quality of the part-edge characteristics shows that higher punch velocity and decreases clearance value can improve the part-edge quality, resulting in smaller burr height and rollover, and a larger shear zone. Furthermore, it could be observed that the part-edge quality improvement when blanking with high punch velocity is much more distinct for stele than for copper. According to blanking theory, this improvement was expected because copper have much higher heat conduction coefficients. Therefore, the heat dissipates faster and the desired stress relief effect does not take place to the same degree as for stele.
Effect of Punch Stroke on Deformation During Sheet Forming Through Finite Element
Akinlabi, Stephen; Akinlabi, Esther
2017-08-01
Forming is one of the traditional methods of making shapes, bends and curvature in metallic components during a fabrication process. Mechanical forming, in particular, employs the use of a punch, which is pressed against the sheet material to be deformed into a die by the application of an external force. This study reports on the finite element analysis of the effects of punch stroke on the resulting sheet deformation, which is directly a function of the structural integrity of the formed components for possible application in the automotive industry. The results show that punch stroke is directly proportional to the resulting bend angle of the formed components. It was further revealed that the developed plastic strain increases as the punch stroke increases.
A new virtual instrument for estimating punch velocity in combat sports.
Urbinati, K S; Scheeren, E; Nohama, P
2013-01-01
For improving the performance in combat sport, especially percussion, it is necessary achieving high velocity in punches and kicks. The aim of this study was to evaluate the applicability of 3D accelerometry in a Virtual Instrumentation System (VIS) designed for estimating punch velocity in combat sports. It was conducted in two phases: (1) integration of the 3D accelerometer with the communication interface and software for processing and visualization, and (2) applicability of the system. Fifteen karate athletes performed five gyaku zuki type punches (with reverse leg) using the accelerometer on the 3rd metacarpal on the back of the hand. It was performed nonparametric Mann-Whitney U-test to determine differences in the mean linear velocity among three punches performed sequentially (p sport.
Relationship between strain and central deflection in small punch creep specimens
International Nuclear Information System (INIS)
Yang Zhen; Wang Zhiwen
2003-01-01
Acquiring information about creep strain directly from small punch creep tests is difficult because the deformation behaviour of the small punch specimen is complicated. A routine is suggested in the present paper to treat this problem indirectly. Based on a finite element analysis, it is proposed that the relationship of central deflection δ to central creep strain ε c of a specimen subjected to creep can be represented approximately by the relationship of central deflection δ to central (elastic-plastic) strain ε of a specimen not subjected to creep. With this hypothesis, the δ∼ε c relation of the small punch creep specimen is obtained by resorting to a rigid-plastic membrane stretch forming model. Finally, small punch creep test results are used to evaluate creep strain and creep strain rate by taking advantage of this δ∼ε c relation
Kinematics of self-initiated and reactive karate punches.
Martinez de Quel, Oscar; Bennett, Simon J
2014-03-01
This study investigated whether within-task expertise affects the reported asymmetry in execution time exhibited in reactive and self-initiated movements. Karate practitioners and no-karate practitioners were compared performing a reverse punch in reaction to an external stimulus or following the intention to produce a response (self-initiated). The task was completed following the presentation of a specific (i.e., life-size image of opponent) or general stimulus and in the presence of click trains or white noise. Kinematic analyses indicated reactive movement had shorter time to peak velocity and movement time, as well as greater accuracy than self-initiated movement. These differences were independent of participant skill level although peak velocity was higher in the karate practice group than in the no-karate practice group. Reaction time (RT) of skilled participants was facilitated by a specific stimulus. There was no effect on RT or kinematic variables of the different type of auditory cues. The results of this study indicate that asymmetry in execution time of reactive and self-initiated movement holds irrespective of within-task expertise and stimulus specificity. This could have implications for training of sports and/or relearning of tasks that require rapid and accurate movements to intercept/contact a target.
Is effective mass in combat sports punching above its weight?
Lenetsky, Seth; Nates, Roy J; Brughelli, Matt; Harris, Nigel K
2015-04-01
The segmental and muscular complexity of the human body can result in challenges when examining the kinetics of impacts. To better understand this complexity, combat sports literature has selected effective mass as a measure of an athlete's inertial contribution to the momentum transfer during the impact of strikes. This measure helps to clarify the analysis of striking kinetics in combat sports. This paper will review: (1) effective mass as a concept and its usage as a measure of impact intensity in combat sports, (2) the neuromuscular pattern known as "double peak muscle activation" which has been theorized to help enhance initial hand velocity upon impact and joint stiffening during impact, (3) the methods and equations used to calculate effective mass, and (4) practitioner recommendations based on the literature. We will argue in this manuscript that the act of punching presents unique challenges to the current understanding of effective mass due to additional force application during impact. This review will improve the understanding of effective mass and its roles in effective striking serving to underpin future research into performance enhancement in striking based combat sports. Copyright © 2014 Elsevier B.V. All rights reserved.
Czech Academy of Sciences Publication Activity Database
Dymáček, Petr; Milička, Karel; Dobeš, Ferdinand
2010-01-01
Roč. 63, Spp. Issue (2010), s. 50-53 ISSN 0018-8069. [International Conference "Determination of Mechanical Properties of Materials by Small Punch and Other Miniature testing Techniques" /1./. Ostrava, 31.08.2010-02.09.2010] R&D Projects: GA AV ČR(CZ) IAA200410801 Institutional research plan: CEZ:AV0Z20410507 Keywords : creep * small punch test * chromium steel Subject RIV: JG - Metallurgy
Punching influence on magnetic properties of the stator teeth of an induction motor
International Nuclear Information System (INIS)
Kedous-Lebouc, A.; Cornut, B.; Perrier, J.C.; Manfe, Ph.; Chevalier, Th.
2003-01-01
In order to study the effects of punching of electrical steel sheets, a suitable geometrical structure able to characterize the stator teeth behavior of an induction motor is proposed and validated. The influence of the punching on a fully processed M330-65A is then characterized. A spectacular degradation of loss and B(H) curves is observed. This leads to a perceptible increase of the no-load machine current
Control program for punched paper tape for the PDP-8/1 computer
International Nuclear Information System (INIS)
German, U.
1976-01-01
A program was developed for the PDP-8/1 computer to control the punched paper tape supplied by the measuring instruments. Any departure from the program is detected by an optical reader which stops the tape and displays the error on an accumulator. This program which is suitable for large amounts of data punched on paper tape has been in use at the Beer-Sheva laboratories for detecting errors in the sample changing operation. (B.G.)
Application of Small Punch Test for Estimation of Fracture Properties of Fe-Al Alloys
Czech Academy of Sciences Publication Activity Database
Dobeš, Ferdinand; Milička, Karel
2010-01-01
Roč. 63, Sp. Iss. (2010), s. 83-86 ISSN 0018-8069. [Determination of Mechanical Properties of Materials by Small Punch and Other Miniature Testing Techniques/1./. Ostrava, 31.08.2010-02.09.2010] R&D Projects: GA ČR GA106/08/1238 Institutional research plan: CEZ:AV0Z20410507 Keywords : small punch test * ductility * iron aluminides Subject RIV: JG - Metallurgy
The Influence of a Padded Hand Wrap on Punching Force in Elite and Untrained Punchers
Directory of Open Access Journals (Sweden)
Andrew J. Galpin
2015-10-01
Full Text Available Punching is integral to success in combat sports, making it a frequent activity during practice/training. Improving safety of this activity benefits both the athlete and training partners. This study was designed to 1 test the precision and reliability of a commercially available striking device and 2 assess the influence of a novel padded hand wrap on punching force in elite and untrained punchers. Fourteen male professional boxers and mixed martial artists (PRO; age=29.2±5.6y; height=180.3±9.0cm; mass=87.1±17.9kg, winning %=73.8±13.8%, number of victories via knockout/technical knockout=35.6± 21.9% and 24 untrained male punchers (UNT; 27.6±6.9y, 177.6±18.3cm, 84.3±16.9kg wore a standardized boxing glove and performed 20 maximal punches (4 sets of 5 into a device designed to measure punching force. All participants performed, in a counterbalanced order, 2 sets of 5 with a standardized hand wrap and 2 sets of 5 with the same wrap plus an additional 1.2cm thick cylinder 4g foam-like pad (WRAP placed over the knuckles. PRO produced significantly more punching force than UNT, regardless of condition. Punching force was lower by 12.6% (p<0.05 for PRO and 8.9% (p<0.05 for UNT with WRAP (compared to no WRAP. These findings suggest WRAP significantly reduces punching force, which may be important for long-term safety of the puncher’s hand and/or the person receiving the strike. Keywords: safety, punching, striking, hitting, combat, pad
Recommended practice for small punch (SP) testing of metallic materials (draft)
International Nuclear Information System (INIS)
Takahashi, Hideaki; Shoji, Tetsuo; Mao, Xinyuan
1988-09-01
This practice covers the determination of fracture toughness characteristics of metallic materials such as ductile to brittle transition temperature (SPDBTT) and elastic-plastic fracture toughness (J ICSP ) using miniature small punch (SP) specimens. Three kinds of specimens with different shape; 10 by 10 by 0.5 mm, 10 by 10 by 0.25 mm and φ3 by 0.25 mm, are selected as the standard SP specimens. Two types of fixture shall be respectively used for the 10 and φ3 specimens. The relationship between load and deflection during buldge tests shall be recorded from low to high temperatures. Following two parameters in relation to fracture toughness are obtained from analyses of load-deflection curves: (1) The SP energy is calculated from the area surrounded with load-deflection curves, which corresponds to the total energy consumed up to the fracture. (2) The equivalent fracture strain (ε-bar qf ) is calculated from the maximum deflection at fracture (δ*). The SPDBTT can be derived from temperature dependence of SP energy, and the J ICSP can be estimated from the rational correlation curve between ε-bar qf and J IC . (author)
International Nuclear Information System (INIS)
Misawa, Toshihei; Hamaguchi, Yoshikazu; Kimura, Akihiko; Eto, Motokuni; Suzuki, Masahide; Nakajima, Nobuya.
1992-01-01
The small punch (SP) test as one of the useful small specimen testing technique (SSTT) has been developed to evaluate the fracture toughness, ductile-brittle transition temperature (DBTT) and tensile properties for neutron irradiated structural materials. The SP tests using the miniaturized specimens of φ3 mm TEM disk and 10 mm 2 coupon were performed for six kinds of ferritic steels of F-82, F-82H, HT-9, JFMS, 2.25-1Mo and SQV2A. It was shown that the temperature dependence of SP fracture energies with scatter in miniaturized testing can give reliable information on the DBTT by use of the statistical analysis based on the Weibull distribution. A good correlation between the DBTT of the SP tests and that of the standard CVN test has been obtained for the various nuclear ferritic steels. The SP test was performed for cryogenic austenitic steels as a way of evaluating elastic-plastic fracture toughness, J IC , on the basis of a universal empirical relationship between J IC and SP equivalent fracture strain, ε-bar qf . The SP testing using the neutron irradiated specimens of 2.25Cr-1Mo, F-82, F-82H and HT-9 steels was successfully applied and presented the neutron radiation induced changes on the DBTT, fracture toughness and tensile properties. (author)
Directory of Open Access Journals (Sweden)
Teng Xu
2017-01-01
Full Text Available A three-degree-of-freedom mathematical vibration model of a high-speed punching press was developed in order to explore the vibration modes of the punching press. A multidomain model of the punching press was established to predict the kinematic state during different conditions, as well as the effects of load fluctuation on the motor speed. Experimental measurements of the acceleration of the punching press were carried out. The results comparison reveals that the multidomain model is consistent with the vibration model and the experimental measurements. Modal analysis and structure modification of the punching press were conducted. The foundation at the base of the punching press was improved against excess of vibration. The effects of the dimensions of the foundation on the vibration were discussed with the aid of the multidomain model. Finally, proper foundation design, able to reduce the vibration, was obtained.
Shear punch testing as a tool for evaluating welded pipeline steel
Energy Technology Data Exchange (ETDEWEB)
Stewart, G.R.; Elwazri, A.; Varano, R.; Yue, S.; Jonas, J.J. [McGill Univ., Montreal, PQ (Canada). Dept. of Metals and Materials Engineering; Pokutylowicz, N. [ExxonMobil Research and Engineering Co., Annandale, NJ (United States)
2005-07-01
This study examined the mechanical properties across a welded joint in a 35 mm steel pipe. Results were compared with microhardness measurements. The chemical composition of the 4130 steel and welding wire included carbon, manganese, silicon, nickel, chromium and molybdenum. The thermal cycles experienced during welding can result in differences in the grain size, phase, composition and morphology of precipitates. These thermal cycles can upset the balance of high strength and good toughness in steels, producing poor toughness in the heat-affected zone (HAZ). In the shear punch test, a flat-ended cylindrical punch was used to produce a 3 mm diameter disk from a sheet specimen with a recommended thickness of 300 to 350 {mu}m. The shear punch test provided tensile property data with only a very small amount of material, which is ideal for testing welds. It also provides full tensile data (yield strength, ultimate tensile strength and elongation) which are not specifically provided by hardness testing. Shear punch techniques can also improve the across-weld resolution of tensile testing. The results showed that the changes in strength properties across the weld were consistent with the microhardness measurements. The change in elongation across the weld joint was successfully measured using the punch test method. The HAZ in the welded joint in this study had a good combination of high strength and ductility, while the weld bead had moderate strength and relatively low ductility. 7 refs., 1 tab., 9 figs.
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Ahmad Hazrina
2017-01-01
Full Text Available This paper investigates the effects of steel fibres as a replacement to the conventional reinforcement under flexural behaviour and punching shear in self-compacting (SCC ribbed slab reinforced with steel fibres. Four ribbed slabs with similar dimensions of 2.8 m length × 1.2 m width and 0.2m thickness were constructed. Two of the samples were considered as control samples (conventionally reinforced with reinforcement bars and welded mesh while another two samples were fully reinforced with 1% (80 kg/m3 volume of steel fibres incorporated to the SCC mix. For the flexural behaviour study, the ribbed slab samples were subjected to two line loads under four point bending. Meanwhile, for the punching shear analysis, the ribbed slab samples were subjected to a point load to simulate loading from the column. The analysis of the experimental results displayed that steel fibres incorporation had been found to effectively delay the first crack occurrence under both flexural and punching shear. The steel fibre replacement has been proven to be able to sustain up to 80% and 73% of the ultimate load resistance for flexural and punching shear, respectively, in comparison to conventionally reinforced ribbed slab structure. The visual observation carried out during the experiment exhibited similar failure mode for both steel fibre reinforced and control samples. This was observed for both flexural and punching shear samples. Overall, it can be concluded that the steel fibres had displayed a promising potential to effectively replace the conventional reinforcements.
Directory of Open Access Journals (Sweden)
Huixia Liu
2015-07-01
Full Text Available The aim of this paper is to fabricate micro-gears via laser shock punching with Spitlight 2000 Nd-YAG Laser, and to discuss effects of process parameters namely laser energy, soft punch properties and blank-holder on the quality of micro-gears deeply. Results show that dimensional accuracy is the best shocked at 1690 mJ. Tensile fracture instead of shear fracture is the main fracture mode under low laser energy. The soft punch might cause damage to punching quality when too high energy is employed. Appropriate thickness and hardness of soft punch is necessary. Silica gel with 200 µm in thickness is beneficial to not only homogenize energy but also propagate the shock wave. Polyurethane films need more energy than silica gel with the same thickness. In addition, blank-holders with different weight levels are used. A heavier blank-holder is more beneficial to improve the cutting quality. Furthermore, the simulation is conducted to reveal typical stages and the different deformation behavior under high and low pulse energy. The simulation results show that the fracture mode changes under lower energy.
Frictionless contact of a rigid punch indenting a transversely isotropic elastic layer
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Rajesh Patra
2016-03-01
Full Text Available This article is concerned with the study of frictionless contact between a rigid punch and a transversely isotropic elastic layer. The rigid punch is assumed to be axially symmetric and is being pressed towards the layer by an applied concentrated load. The layer is resting on a rigid base and is assumed to be ufficiently thick in comparison with the amount of indentation by the rigid punch. The relationship between the applied load $P$ and the contact area is obtained by solving the mathematically formulated problem through use of Hankel transform of different order. Effect of indentation on the distribution of normal stress at the surface as well as the relationship between the applied load and the area of contact have been shown graphically.
Flat punch adhesion: transition from fracture-based to strength-limited pull-off
International Nuclear Information System (INIS)
Jiang, Yijie; Turner, Kevin T; Grierson, David S
2014-01-01
The adhesion of a cylindrical flat punch to a surface due to interatomic forces is a well-known problem that is important in many applications, including indentation experiments and the adhesion of fibrillar structures. Traditionally, the pull-off force has been related to the work of adhesion and punch geometry via the Kendall solution that uses a Griffith energy balance to assess crack propagation and pull-off. More recently, it has been shown that under certain conditions, notably at small punch diameters, the contact can behave in a ‘strength-limited’ fashion in which the interface separates uniformly rather than via crack propagation. Here, a Maugis-Dugdale-type analysis of power-law-shaped bodies in contact is used to examine the change in behaviour from the fracture-based Kendall solution to strength-limited pull-off for cylindrical flat punches. The transition from fracture-based to strength-limited behaviour is described in terms of a non-dimensional parameter that is similar to previous quantities used to describe the transition and is a function of the punch size, the elasticity of the contact, and the adhesion properties. The results of this relatively simple analysis compare favourably with results from more complex computational simulations. In addition, the results are used to develop a function that quantifies the transition between the Kendall solution and the strength-limited solution in order to facilitate interpretation of adhesion measurements in the transition regime between the two limits. Finally, the power-law analysis is used to assess the sensitivity of the transition to the exact shape of the punch. (paper)
Development and validation of the small punch test for UHMWPE used in total joint replacements
Energy Technology Data Exchange (ETDEWEB)
Edidin, A.A. [Drexel Univ., Philadelphia, PA (United States). School of Biomedical Engineering, Science and Health Systems; Howmedica Osteonics Corp., Allendale, NJ (United States); Kurtz, S.M. [Drexel Univ., Philadelphia, PA (United States). School of Biomedical Engineering, Science and Health Systems; Thomas Jefferson Univ., Philadelphia, PA (United States). Dept. of Orthopaedic Surgery; Exponent, Inc., Philadelphia, PA (United States)
2001-07-01
In order to better understand the mechanical effects of oxidative degradation, improved oxidative stability and crosslinking on ultra-high molecular weight polyethylene (UHMWPE), a unique miniature specimen mechanical testing technique, known as the small punch test, was developed for evaluating total joint replacement components. The small punch test involves deforming a disk-shaped specimen having a thickness of 0.5 mm and a diameter of 6.4 mm. In addition to its small specimen size, the small punch test differs from conventional testing in that deformation of the UHMWPE specimen occurs under multiaxial loading conditions. Using the small punch test, we have traced the evolution of mechanical behavior in UHMWPE after natural (shelf-storage) and accelerated aging conditions. In addition, we have determined relationships between the mechanical behavior of UHMWPE and the biologically relevant wear debris volume generated in total hip replacements. The small punch test has also been used to investigate the effects of radiation crosslinking which has been shown to improve the wear performance in an in vitro hip simulator. However, the crosslinking and subsequent thermal processes used to improve the wear behavior may compromise the native mechanical behavior by changing the ductility and toughness of the UHMWPE bearing. The primary objective of this study was to investigate which tradeoffs exist related to the mechanical behavior associated with various clinically available types of highly crosslinked and thermally treated UHMWPE. We also review the development and validation of the small punch disk bend test and highlight its application to problems of clinical relevance in both hip and knee arthroplasty. (orig.)
Prediction of punching shear capacities of two-way concrete slabs reinforced with FRP bars
Directory of Open Access Journals (Sweden)
Ibrahim M. Metwally
2013-08-01
Full Text Available Where corrosion of steel reinforcement is a concern, fiber-reinforced polymer (FRP reinforcing bar or grid reinforcement provides an alternative reinforcement for concrete flat slabs. The existing provisions for punching of slabs in most international design standards for reinforced concrete are based on tests of steel reinforced slabs. The elastic stiffness and bonding characteristics of FRP reinforcement are sufficiently different from those of steel to affect punching strength [1]. This paper evaluates the punching shear strength of concrete flat slabs reinforced with different types of fiber-reinforced polymer (FRP. A total of 59 full-size slabs were constructed and tested collected from the literature of FRP bars reinforced concrete slabs. The test parameters were the amount of FRP reinforcing bars, Young’s modulus of FRP bars, slab thickness, loaded areas and concrete compressive strength. The experimental punching shear strengths were compared with the available theoretical predictions, including the ACI 318 Code, BS 8110 Code, ACI 440 design guidelines, and a number of models proposed by some researchers in the literature. Two approaches for predicting the punching strength of FRP-reinforced slabs are examined. The first is an empirical new model which is considered as a modification of El-Gamal et al. [2] model. The second is a Neural Networks Technique; which has been developed to predict the punching shear capacity of FRP reinforced concrete slabs. The accuracies of both methods were evaluated against the experimental test data. They attained excellent agreement with available test results compared to the existing design formulas.
Usage of prestressed vertical bolts for retrofitting flat slabs damaged due to punching shear
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Hamed S. Askar
2015-09-01
An experimental investigation with the objective of retrofitting flat slabs damaged due to punching shear using prestressed vertical bolts is presented in this paper. The parameters examined in this study are vertical prestressed bolts with different ratios within the slab thickness, slab thickness and central column size. Through the experimental tests the load carrying capacity, deformation characteristics and the cracking behavior have been investigated. A comparison between the behavior of retrofitted slabs and their references showed that the proposed system of repair is effective and could be used in practice. A comparison between the experimental results and calculated punching failure load based on the formulas adopted by different codes, showed a reasonable agreement.
Experimental and Computational Study of Ductile Fracture in Small Punch Tests
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Betül Gülçimen Çakan
2017-10-01
Full Text Available A unified experimental-computational study on ductile fracture initiation and propagation during small punch testing is presented. Tests are carried out at room temperature with unnotched disks of different thicknesses where large-scale yielding prevails. In thinner specimens, the fracture occurs with severe necking under membrane tension, whereas for thicker ones a through thickness shearing mode prevails changing the crack orientation relative to the loading direction. Computational studies involve finite element simulations using a shear modified Gurson-Tvergaard-Needleman porous plasticity model with an integral-type nonlocal formulation. The predicted punch load-displacement curves and deformed profiles are in good agreement with the experimental results.
Experimental and Computational Study of Ductile Fracture in Small Punch Tests.
Gülçimen Çakan, Betül; Soyarslan, Celal; Bargmann, Swantje; Hähner, Peter
2017-10-17
A unified experimental-computational study on ductile fracture initiation and propagation during small punch testing is presented. Tests are carried out at room temperature with unnotched disks of different thicknesses where large-scale yielding prevails. In thinner specimens, the fracture occurs with severe necking under membrane tension, whereas for thicker ones a through thickness shearing mode prevails changing the crack orientation relative to the loading direction. Computational studies involve finite element simulations using a shear modified Gurson-Tvergaard-Needleman porous plasticity model with an integral-type nonlocal formulation. The predicted punch load-displacement curves and deformed profiles are in good agreement with the experimental results.
Fabrication and loading of oral drug delivery microcontainers using hot punching
DEFF Research Database (Denmark)
Petersen, Ritika Singh; Borre, Mads T.; Keller, Stephan Sylvest
2015-01-01
In this paper, poly-l-lactic acid (PLLA) solution is spin coated to achieve a PLLA layer of 55 μm thickness. Hot punching with a Ni stamp is optimized to fabricate microcontainers in PLLA. Process optimization of thermal bonding of the microcontainers to a poly acrylic acid (PAA) layer is perform...... by modifying sample preparation and varying temperature. The fabricated microcontainers are loaded by hot punching in a spin coated drug polymer film of furosemide and poly-e-caprolactone (PCL)....
Directory of Open Access Journals (Sweden)
Ahmed Ibrahim
2016-12-01
The obtained results indicate that, the proposed shear reinforcement system has a positive effect in the enhancement of both the punching shear capacity and the strain energy of interior slab–column connection of both normal and high strength concrete. The general finite element software ANSYS can be used successfully to simulate the punching shear behavior of reinforced concrete flat plates.
International Nuclear Information System (INIS)
Baik, J.M.; Kameda, J.; Buck, O.
1983-01-01
Small punch tests were developed to determine the ductile-brittle transition temperature of nickel-chromium (Ni-Cr) steels having various degrees of temper embrittlement and various microstructures. It was found that the small punch test clearly shows the ductile-brittle transition behavior of the temper-embrittled steels. The measured values were compared with those obtained from Charpy impact and uniaxial tensile tests. The effects of punch tip shape, a notch, and the strain rate on the ductile-brittle transition behavior were examined. It was found that the combined use of a notch, high strain rates, and a small punch tip strongly affects the ductile-brittle transition behavior. Considerable variations in the data were observed when the small punch tests were performed on coarse-grained steels. Several factors controlling embrittlement measurements of steels are discussed in terms of brittle fracture mechanisms
Directory of Open Access Journals (Sweden)
Vinita Khandegar
2018-06-01
Full Text Available The electrocoagulation setup must be optimized in order to design an economically feasible process. Therefore, in this work, the effect of the punched aluminum electrode on the performance of the electrocoagulation (EC has been investigated. A series of experiments were performed for treatment of sewage wastewater using plane electrode and compare with punched electrodes. Effect of contact time, voltage, electrode spacing and stirring speed has been optimized for removal of Biochemical oxygen demand (BOD and Total dissolved solids (TDS. It was observed that the performance of electrocoagulation process increased using punched electrode. Also, the less operating cost noticed in punched electrode as compared to a plane electrode for (70–80% removal of BOD and TDS. These data would be useful in designing of an EC reactor to obtain high removal efficiency at low energy consumption. Keywords: Electrocoagulation, Sewage wastewater, Aluminum, Plane, Punched electrode
Diarra, Harona; Mazel, Vincent; Busignies, Virginie; Tchoreloff, Pierre
2015-09-30
Finite elements method was used to study the influence of tablet thickness and punch curvature on the density distribution inside convex faced (CF) tablets. The modeling of the process was conducted on 2 pharmaceutical excipients (anhydrous calcium phosphate and microcrystalline cellulose) by using Drucker-Prager Cap model in Abaqus(®) software. The parameters of the model were obtained from experimental tests. Several punch shapes based on industrial standards were used. A flat-faced (FF) punch and 3 convex faced (CF) punches (8R11, 8R8 and 8R6) with a diameter of 8mm were chosen. Different tablet thicknesses were studied at a constant compression force. The simulation of the compaction of CF tablets with increasing thicknesses showed an important change on the density distribution inside the tablet. For smaller thicknesses, low density zones are located toward the center. The density is not uniform inside CF tablets and the center of the 2 faces appears with low density whereas the distribution inside FF tablets is almost independent of the tablet thickness. These results showed that FF and CF tablets, even obtained at the same compression force, do not have the same density at the center of the compact. As a consequence differences in tensile strength, as measured by diametral compression, are expected. This was confirmed by experimental tests. Copyright © 2015 Elsevier B.V. All rights reserved.
Enhancements to the Image Analysis Tool for Core Punch Experiments and Simulations (vs. 2014)
Energy Technology Data Exchange (ETDEWEB)
Hogden, John Edward [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Unal, Cetin [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2017-11-06
A previous paper (Hogden & Unal, 2012, Image Analysis Tool for Core Punch Experiments and Simulations) described an image processing computer program developed at Los Alamos National Laboratory. This program has proven useful so developement has been continued. In this paper we describe enhacements to the program as of 2014.
Lawson, A J; Bernstone, L; Hall, S K
2016-03-01
In dried blood spot analysis, punch location and variations in applied sample volume and haematocrit can produce different measured concentrations of analytes. We investigated the magnitude of these effects in newborn screening in the UK. Heparinized blood spiked with thyroid stimulating hormone (TSH), phenylalanine, tyrosine, leucine, methionine, octanoyl carnitine (C8), and immunoreactive trypsinogen (IRT) was spotted onto filter paper: (i) at a constant haematocrit of 50% at various volumes, and (ii) at a range of haematocrits using a constant volume. Subpunches (3.2 mm) of the dried blood spots were then analysed. Compared with a central punch from a 50 µL blood spot with 50% haematocrit, 10 µL spots can have significantly lower measured concentrations of all analytes, with decreases of 15% or more observed for leucine, methionine, phenylalanine, and tyrosine. Punching at the edge of a spot can increase measured concentrations up to 35%. Higher haematocrit decreased measured TSH and C8 yet increased amino acids and IRT by 15% compared with 50% haematocrit. Lower haematocrits had the opposite effect, but only with higher concentrations of some analytes. Differences in blood spot size, haematocrit and punch location substantially affect measured concentrations for analytes used in the UK newborn screening programme, and this could affect false positive and negative rates. To minimize analytical bias, these variables should be controlled or adjusted for where possible. © The Author(s) 2015.
Effect of Friction Coefficient on the Small Punch Creep Behavior of AISI 316L Stainless Steel
International Nuclear Information System (INIS)
Kim, Bum-Joon; Cho, Nam-Hyuck; Kim, Moon-K; Lim, Byeong-Soo
2011-01-01
Small punch creep testing has received attention due to the convenience of using smaller specimens than those of conventional uniaxial creep tests, which enables creep testing on developing or currently operational components. However, precedent studies have shown that it is necessary to consider friction between the punch and specimen when computing uniaxial equivalent stress from a finite element model. In this study, small punch creep behaviors of AISI 316L stainless steel, which is widely used in high temperature-high pressure machineries, have been compared for the two different ceramic balls such as Si 3 N 4 and Al 2 O 3 . The optimal range of the friction coefficient is 0.4⁓0.5 at 650°C for the best fit between experimental and simulation data of AISI 316 L stainless steel. The higher the friction coefficient, the longer the creep rupture time is. Therefore, the type of ceramic ball used must be specified for standardization of small punch creep testing.
Short term creep small punch testing of P91 and P92 steels,
Czech Academy of Sciences Publication Activity Database
Dymáček, Petr
2011-01-01
Roč. 465, - (2011), s. 179-182 ISSN 1013-9826. [Materials Structure & Micromechanics of Fracture 6. Brno, 28.6.2010-30.6,2010] R&D Projects: GA AV ČR(CZ) IAA200410801 Institutional research plan: CEZ:AV0Z20410507 Keywords : creep * small punch test * chromium steel Subject RIV: JG - Metallurgy
Splitting behaviour of timber loaded perpendicular to the grain by punched metal plates
Schoenmakers, J.C.M.; Jorissen, A.J.M.; Leijten, A.J.M.; Aratake, S. xx
2008-01-01
Nowadays, prefabricated timber trusses are widely used as load-bearing roof structures. The majority of these trusses are produced with punched metal plates (PMP) to connect two or more timber elements of the same thickness, see Figure 2. In these structures sufficient overlap is required to prevent
Analysis of ancient Indian silver punch-marked coins by external PIXE
International Nuclear Information System (INIS)
Rautray, Tapash R.; Nayak, Suman S.; Tripathy, Bipin B.; Das, Saubhagyalaxmi; Das, Manas R.; Das, Satya R.; Chattopadhyay, Pranab K.
2011-01-01
Seven silver punch-marked coins were analysed using external particle induced X-ray emission technique. The main group of elements like Ag, Cu, Au, Pb and Fe were estimated along with a number of trace/minor elements such as K, Ca, Ti, V, Cr, Mn, Co, Ni and Rb in the analysed silver coins. Gold was found in all the coins and varied between 0.7% and 6.2% indicating the better economic condition of that civilisation. - Highlights: → The silver punch-marked coins, in the current study, were in use in India between 6th century BC to 6th century AD and have been analysed by in-air PIXE. → These sets of coins have immense archaeological importance because of their very rare availability. → These coins are distinguished from other coins because of the presence of gold as major element. → While the British period coins were fabricated using modern technologies, the punch-marked coins were shaped manually with developed metal technology. → The analysis of punch-marked coins using external PIXE beam has been done for the first time, which is unique of its kind.
Lecheler, S.
2014-01-01
In Introduction to Social Research, Keith F. Punch wants to ‘demystify’ and ‘simplify’ the research process, in an attempt to show that quality research can always be achieved. With its straightforward language, an intuitive structure, and well-defined learning objectives, this book does just that,
Evaluation of Replacement Grafts and Punch Grafts in the Treatment of Vitiligo
Directory of Open Access Journals (Sweden)
Singh Ajit Kumar
1980-01-01
Full Text Available Thirtycasesof vitiligo eachwithminimum of two lesions undent replacement graft and multiple punch grafts in one lesion each. Complications observed at the recipient site like infection and raised nigosed surface were significantly more in replacement grafts. Hypopigmentation of the graft was significantly more when the disease was progressive.
Small Punch Tests at Oxide Scales Surface of Structural Steel and Low Silicon Steel
Czech Academy of Sciences Publication Activity Database
Hrabovský, J.; Dobeš, Ferdinand; Horský, J.
2014-01-01
Roč. 82, 3-4 (2014), s. 297-310 ISSN 0030-770X Institutional support: RVO:68081723 Keywords : Small punch * Oxide scales * X-ray diffraction * Mechanical properties Subject RIV: JK - Corrosion ; Surface Treatment of Materials Impact factor: 1.140, year: 2014
Review of Punching Shear Behaviour of Flat Slabs Reinforced with FRP Bars
Mohamed, Osama A.; Khattab, Rania
2017-10-01
Using Fibre Reinforced Polymer (FRP) bars to reinforce two-way concrete slabs can extend the service life, reduce maintenance cost and improve-life cycle cost efficiency. FRP reinforcing bars are more environmentally friendly alternatives to traditional reinforcing steel. Shear behaviour of reinforced concrete structural members is a complex phenomenon that relies on the development of internal load-carrying mechanisms, the magnitude and combination of which is still a subject of research. Many building codes and design standards provide design formulas for estimation of punching shear capacity of FRP reinforced flat slabs. Building code formulas take into account the effects of the axial stiffness of main reinforcement bars, the ratio of the perimeter of the critical section to the slab effective depth, and the slab thickness on the punching shear capacity of two-way slabs reinforced with FRP bars or grids. The goal of this paper is to compare experimental data published in the literature to the equations offered by building codes for the estimation of punching shear capacity of concrete flat slabs reinforced with FRP bars. Emphasis in this paper is on two North American codes, namely, ACI 440.1R-15 and CSA S806-12. The experimental data covered in this paper include flat slabs reinforced with GFRP, BFRP, and CFRP bars. Both ACI 440.1R-15 and CSA S806-12 are shown to be in good agreement with test results in terms of predicting the punching shear capacity.
Effect of CFRP and TRM Strengthening of RC Slabs on Punching Shear Strength
Directory of Open Access Journals (Sweden)
Husain Abbas
Full Text Available Abstract The paper presents experiments involving punching of RC slabs strengthened using externally bonded carbon fiber reinforced polymer (CFRP sheet and textile reinforced mortar (TRM. Twelve RC slab specimens of two concrete grades (39.9 and 63.2 MPa and employing two strengthening schemes (CFRP and TRM were tested. Specimens were supported on two opposite edges. Experimental load-displacement variations show two peak loads in strengthened slabs and one peak followed by a plateau in control. Second peak or the plateau corresponds to the combined action of aggregate interlock and the dowel action of back face rebars and strengthening layers. The dowel action of back face rebars and strengthening layers had no role in ultimate punching load (i.e. first peak. Strengthened slabs showed 9-18% increase in ultimate punching load (i.e. first peak whereas there was significant increase in the second peak load (190-276% for CFRP; 55-136% for TRM and energy absorption (~66% for CFRP and 22-56% for TRM. An analytical model was also developed for predicting the punching shear strength (first and second peaks of strengthened slabs showing good comparison with experiments.
Very heavy iron-punching concretes; Betons tres lourds a base de riblons
Energy Technology Data Exchange (ETDEWEB)
Dubois, F [Commissariat a l' Energie Atomique, Saclay(France). Centre d' Etudes Nucleaires
1966-07-01
The present report deals with all the heavy iron-punching concretes, metallic wastes produced by the transformation industry. After a detailed description of the physical properties of metallic aggregates, a classification of heavy mortars is given, into three main categories: steel-shot grouts d = 5,3 - 6; steel-shot grouts mixed with a mineral d = 3,7 - 4,2; injection heavy grouts d = 3,5 - 4. The following chapter describes iron-punching concretes the most used in the atomic industry: iron-punching concretes mixed with cast-iron - iron-punching concretes mixed with magnetite; iron-punching concretes mixed with barite; iron-punching concretes mixed with limonite; iron-punching concretes mixed with boron. The compositions of these concretes are given together with their physical and mechanical characteristics. Numerous diagrams make it possible to find rapidly the proportions of the constituents of these concretes as a function of the required density. Technical advice and specifications are given in an appendix together with a bibliography of these heavy concretes. (author) [French] Le present rapport traite de l'ensemble des betons lourds realises a l'aide de riblons, dechets metalliques fournis par l'industrie de transformation. Apres une description detaillee des proprietes physiques des agregats metalliques, les mortiers lourds sont d'abord presentes en les classant en trois grandes categories: les mortiers a base de grenailles d 5,3 a 6; les mortiers a base de grenailles avec addition d'un mineral d 3,7 a 4,2; les mortiers lourds injectables d = 3,5 a 4. Le chapitre suivant decrit les betons a base de riblons les plus utilises, dans l'industrie atomique: les betons de riblons avec addition de fonte; les betons de riblons avec addition de magnetite; les betons de riblons avec addition de barytine; les betons de riblons avec addition de limonite; les betons de riblons avec addition de bore. Les compositions de ces betons ainsi que leurs caracteristiques
Very heavy iron-punching concretes; Betons tres lourds a base de riblons
Energy Technology Data Exchange (ETDEWEB)
Dubois, F. [Commissariat a l' Energie Atomique, Saclay(France). Centre d' Etudes Nucleaires
1966-07-01
The present report deals with all the heavy iron-punching concretes, metallic wastes produced by the transformation industry. After a detailed description of the physical properties of metallic aggregates, a classification of heavy mortars is given, into three main categories: steel-shot grouts d = 5,3 - 6; steel-shot grouts mixed with a mineral d = 3,7 - 4,2; injection heavy grouts d = 3,5 - 4. The following chapter describes iron-punching concretes the most used in the atomic industry: iron-punching concretes mixed with cast-iron - iron-punching concretes mixed with magnetite; iron-punching concretes mixed with barite; iron-punching concretes mixed with limonite; iron-punching concretes mixed with boron. The compositions of these concretes are given together with their physical and mechanical characteristics. Numerous diagrams make it possible to find rapidly the proportions of the constituents of these concretes as a function of the required density. Technical advice and specifications are given in an appendix together with a bibliography of these heavy concretes. (author) [French] Le present rapport traite de l'ensemble des betons lourds realises a l'aide de riblons, dechets metalliques fournis par l'industrie de transformation. Apres une description detaillee des proprietes physiques des agregats metalliques, les mortiers lourds sont d'abord presentes en les classant en trois grandes categories: les mortiers a base de grenailles d 5,3 a 6; les mortiers a base de grenailles avec addition d'un mineral d 3,7 a 4,2; les mortiers lourds injectables d = 3,5 a 4. Le chapitre suivant decrit les betons a base de riblons les plus utilises, dans l'industrie atomique: les betons de riblons avec addition de fonte; les betons de riblons avec addition de magnetite; les betons de riblons avec addition de barytine; les betons de riblons avec addition de limonite; les betons de riblons avec addition de bore. Les compositions de ces betons ainsi que
Directory of Open Access Journals (Sweden)
Masami Kojima
2016-12-01
Full Text Available This paper aims to describe the effect of tool geometry on cutting characteristics of a 1.0 mm thickness acrylic worksheet subjected to a punch/die shearing. A set of side-wedge punch and side-wedge die which had the edge angle of 30°, 60° and/or 90° was prepared and used for cutting off the worksheet. A load cell and a CCD camera were installed in the cutting system to investigate the cutting load resistance and the side-view deformation of the worksheet. From experimental results, it was revealed that a cracking pattern at a sheared zone was remarkably affected by the edge angle of cutting tool. A cracking direction was almost coincident to the edge angle when considering the punch/die edge angle of 30°, while any matching of them was not observed in case of the punch/die edge angle of 60°, 90°. By using the 30° side-wedge tool, a flat-smooth sheared surface was generated. When combing the punch edge angle of 90° and the die edge angle of 60°, the cracking profile was characterized by the both edge angles for each part (die and punch. Carrying out an elasto-plastic finite element method analysis of cutter indentation with a few of symmetric and asymmetric punch/die edges, the stress distribution and deformation flow at the sheared zone were discussed with the initiation of surface cracks
International Nuclear Information System (INIS)
Kim, M. C.; Lee, B. S.; Oh, Y. J.
2003-01-01
A Small Punch (SP) test was performed to evaluate the ductile-brittle transition temperature before and after neutron irradiation in Reactor Pressure Vessel (RPV) steels produced by different manufacturing (refining) processes. The results were compared to the standard transition temperature shifts from the Charpy test and Master Curve fracture toughness test in accordance with the ASTM standard E1921. The samples were taken from 1/4t location of the vessel thickness and machined into a 10x10x0.5mm dimension. Irradiation of the samples was carried out in the research reactor at KAERI (HANARO) at about 290 .deg. C of the different fluence levels respectively. SP tests were performed in the temperature range of RT to -196 .deg. C using a 2.4mm diameter ball. For the materials before and after irradiation, SP transition temperatures (T sp ), which are determined at the middle of the upper and lower SP energies, showed a linear correlation with the Charpy index temperature, T 41J . T sp from the irradiated samples was increased as the fluence level increased and was well within the deviation range of the unirradiated data. The TSP had a correlation with the reference temperature (T 0 ) from the master curve method using a pre-cracked Charpy V-notched (PCVN) specimen
High temperature strength analysis of welded joint of RAF's by small punch test
Energy Technology Data Exchange (ETDEWEB)
Kato, T. [Muroran Institute of Technology, Dept. of Materials Science and Engineeering, Hokkaido (Japan); Komazaki, S.; Kohno, Y. [Muroran Institute of Technology, Muroran (Japan); Tanigawa, H. [Japan Atomic Energy Agency, Naga-gun, Ibaraki-ken (Japan); Kohyama, A. [Kyoto Univ., Institute of Advanced Energy (Japan)
2007-07-01
Full text of publication follows: Nucleation and growth of microvoids and/or small cracks in fine-grained heat affected zone (HAZ) after long-term service operation, which is recognized as Type IV creep damage, has recently been a worldwide issue for high Cr ferritic steels. In our group, a small punch (SP) creep test has been successfully applied to evaluate this damage of low alloy ferritic steel. However, the HAZ of fusion reactor material welded by electron-beam (EB) welding is so narrow that it is not easy to evaluate its mechanical properties by conventional tests including the SP creep test with a plate-type specimen (10 x 10 x 0.5 mm{sup 3}). In this study, the SP creep test using a further miniaturized specimen was developed and applied to the welded joint of reduced activation ferritic steels (RAFs), F82H-IEA (Fe-8Cr-2W-0.2V-0.02Ta), for measuring creep properties of the HAZ. For the SP creep test, TEM disk-type samples (diam. 3.0 x 0.30 mm) were removed from the base metal (BM), weld metal (WM) and HAZ, respectively. The specimen surfaces were polished up to a 0.05 {mu}m alumina powder finish and the specimen's thickness was finally adjusted to 0.25 mm. The SP creep tests were performed at temperatures of 823{approx}973 K and under loads ranging from 20 to 200 N. A constant load was applied to the center of the specimen through the Si{sub 3}N{sub 4} bail (diam. 1.0 mm) using the electric servo motor. The central deflection of the specimen was monitored by measuring the displacement of the compression rod. The tests were carried out in an argon gas atmosphere and the gas was continuously passed through during the test to prevent severe oxidation of the specimen. The differences in SP creep properties such as rupture time and minimum creep rate between the BM, WM and HAZ were discussed in terms of microstructural changes during welding thermal cycles. In addition, the result obtained from the BM was correlated with those of uniaxial creep test
A possible mechanism for electron-bombardment-induced loop punching in helium-implanted materials
International Nuclear Information System (INIS)
Donnelly, S.E.
1983-01-01
The recently proposed mechanism for the punching of dislocation loops by overpressurized helium bubbles in molybdenum is studied quantitatively. According to this mechanism, under the electron beam of the transmission microscope, He atoms are excited or ionized and the resulting excited species (excited He atoms and free electrons) are responsible for the pressure rise in the gas beyond the threshold for loop punching. In the model, the pressure increase is attributed to a reduction of the effective volume accessible to the gas due to the formation of a cavity around each excited species. The radius of this cavity is evaluated and, also, the excited fraction required to reach the threshold is discussed in terms of excitation life times. (author)
Cone penetrometer tests and HydroPunch sampling: A screening technique for plume definition
International Nuclear Information System (INIS)
Smolley, M.; Kappmeyer, J.C.
1991-01-01
Cone penetrometer tests and HydroPunch sampling were used to define the extent of volatile organic compounds in ground water. The investigation indicated that the combination of the these techniques is effective for obtaining ground water samples for preliminary plume definition. HydroPunch samples can be collected in unconsolidated sediments and the analytical results obtained from these samples are comparable to those obtained from adjacent monitoring wells. This sampling method is a rapid and cost-effective screening technique for characterizing the extent of contaminant plumes in soft sediment environments. Use of this screening technique allowed monitoring wells to be located at the plume boundary, thereby reducing the number of wells installed and the overall cost of the plume definition program
Love-type wave propagation in a pre-stressed viscoelastic medium influenced by smooth moving punch
Singh, A. K.; Parween, Z.; Chatterjee, M.; Chattopadhyay, A.
2015-04-01
In the present paper, a mathematical model studying the effect of smooth moving semi-infinite punch on the propagation of Love-type wave in an initially stressed viscoelastic strip is developed. The dynamic stress concentration due to the punch for the force of a constant intensity has been obtained in the closed form. Method based on Weiner-hopf technique which is indicated by Matczynski has been employed. The study manifests the significant effect of various affecting parameters viz. speed of moving punch associated with Love-type wave speed, horizontal compressive/tensile initial stress, vertical compressive/tensile initial stress, frequency parameter, and viscoelastic parameter on dynamic stress concentration due to semi-infinite punch. Moreover, some important peculiarities have been traced out and depicted by means of graphs.
Influence of friction on stress and strain distributions in small punch creep test models
Czech Academy of Sciences Publication Activity Database
Dymáček, Petr; Seitl, Stanislav; Milička, Karel; Dobeš, Ferdinand
417-418, - (2010), s. 561-564 ISSN 1013-9826. [International Conference on Fracture and Damage Mechanics /8./. Malta, 08.09.2009-10.09.2009] R&D Projects: GA AV ČR(CZ) IAA200410801; GA AV ČR(CZ) 1QS200410502 Institutional research plan: CEZ:AV0Z20410507 Keywords : small punch test * creep * chromium steel * finite element method Subject RIV: JG - Metallurgy www.scientific.net/KEM.417-418.561
Hot embossing and mechanical punching of biodegradable microcontainers for oral drug delivery
DEFF Research Database (Denmark)
Petersen, Ritika Singh; Mahshid, Rasoul; Andersen, Nis Korsgaard
2015-01-01
A process has been developed to fabricate discrete three-dimensional microcontainers for oral drug delivery application in Poly-L-Lactic Acid (PLLA) polymer. The method combines hot embossing for the definition of holes in a PLLA film and mechanical punching to penetrate the polymer layer around...... and shapes of microcontainers. Finally, the process is compatible with roll-to-roll processing that could lead to low cost high volume production. © 2014 Elsevier B.V. All rights reserved....
Treatment of Die-Punch Fractures with 3D Printing Technology.
Chen, Chunhui; Cai, Leyi; Zhang, Chuanxu; Wang, Jianshun; Guo, Xiaoshan; Zhou, Yifei
2017-07-19
We evaluated the feasibility, accuracy and effectiveness of applying three-dimensional (3D) printing technology for preoperative planning for die-punch fractures. A total of 107 patients who underwent die-punch fracture surgery were enrolled in the study. They were randomly divided into two groups: 52 cases in the 3D model group and 55 cases in the routine group. A 3D digital model of each die-punch fracture was reconstructed in the 3D group. The 3D digital model was imported to a 3D printer to build the full solid model. The operation time, blood loss volume, and the number of intraoperative fluoroscopy were recorded. Follow-up was performed to evaluate the patients' surgical outcomes. Treatment of die-punch fractures using the 3D printing approach reduced the number of intraoperative fluoroscopy, blood loss volume, and operation time, but did not improve wrist function compared to those in the routine group. The patients wanted the doctor to use the 3D model to introduce the condition and operative plan because it was easier for them to understand. The orthopedic surgeons thought that the 3D model was useful for communicating with their patients, but their satisfaction with the preoperative plan was much lower than the benefit of using the 3D model to communicate with their patients. 3D printing technology produced more accurate morphometric information for orthopedists to provide personalized surgical planning and communicate better with their patients. However, it is difficult to use widely in the department of orthopedics.
Estimation of ductility of Fe-Al alloys by means of small punch test
Czech Academy of Sciences Publication Activity Database
Dobeš, Ferdinand; Milička, Karel
Roč.18, č.7 (2010), s. 1357-1359 ISSN 0966-9795. [Discussion Meeting on the Development of Innovative Iron Aluminium Alloys /5./. Praha, 21.09.2009-24.09.2009] R&D Projects: GA ČR GA106/08/1238 Institutional research plan: CEZ:AV0Z20410507 Keywords : iron aluminides * brittleness * small punch test Subject RIV: JG - Metallurgy Impact factor: 2.327, year: 2010
Study of the upper die clamping conditions in the small punch test
Czech Academy of Sciences Publication Activity Database
Andrés, D.; Dymáček, Petr
86A, DEC (2016), s. 117-123 ISSN 0167-8442 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0068 Institutional support: RVO:68081723 Keywords : Small punch test * Finite element method * Parametric study * High temperature * Creep Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 2.659, year: 2016 http://www.sciencedirect.com/science/article/pii/S0167844216301835
Bingul, Bergun Meric; Bulgun, Cigdem; Tore, Ozlem; Bal, Erdal; Aydin, Mensure
2018-01-01
The aim of this study was to investigate the effects of biomechanic factors to teach different hook punches in boxing. Eight light middleweight boxing athletes (mean age ± SD 19.00 ± 2.00 yrs, mean height ± SD 173.88 ± 3.89 cm, mean weight ± SD 64.25 ± 4.66 kg) participated in this study. Athletes performed a trial using three different hook punch…
ACHOURI, Mohamed; GERMAIN, Guénaël; DAL SANTO, Philippe; SAIDANE, Delphine
2014-01-01
Sequential sheet metal forming processes can result in the accumulation of work hardening and damage effects in the workpiece material. The mechanical strength of the final component depends on the “evolution” of these two characteristics in the different production steps. The punching process, which is usually in the beginning of the production chain, has an important impact on the stress, strain and damage states in the punched zones. It is essential that the influence of these mechanical f...
Examining the microtexture evolution in a hole-edge punched into 780 MPa grade hot-rolled steel
Energy Technology Data Exchange (ETDEWEB)
Shin, J.H.; Kim, M.S. [Department of Printed Electronics Engineering, Sunchon National University, 315 Maegok, Sunchon, Jeonnam 540-950 (Korea, Republic of); Kim, S.I.; Seo, S.J. [POSCO Technical Research Laboratories, Gwangyang 545-090 (Korea, Republic of); Choi, S.-H., E-mail: shihoon@sunchon.ac.kr [Department of Printed Electronics Engineering, Sunchon National University, 315 Maegok, Sunchon, Jeonnam 540-950 (Korea, Republic of)
2016-08-15
The deformation behavior in the hole-edge of 780 MPa grade hot-rolled steel during the punching process was investigated via microstructure characterization and computational simulation. Microstructure characterization was conducted to observe the edges of punched holes through the thickness direction, and electron back-scattered diffraction (EBSD) was used to analyze the heterogeneity of the deformation. Finite element analysis (FEA) that could account for a ductile fracture criterion was conducted to simulate the deformation and fracture behaviors of 780 MPa grade hot-rolled steel during the punching process. Calculation of rotation rate fields at the edges of the punched holes during the punching process revealed that metastable orientations in Euler space were confined to specific orientation groups. Rotation-rate fields effectively explained the stability of the initial texture components in the hole-edge region during the punching process. A visco-plastic self-consistent (VPSC) polycrystal model was used to calculate the microtexture evolution in the hole-edge region during the punching process. FEA revealed that the heterogeneous effective strain was closely related to the heterogeneity of the Kernel average misorientation (KAM) distribution in the hole-edge region. A simulation of the deformation microtexture evolution in the hole-edge region using a VPSC model was in good agreement with the experimental results. - Highlights: •We analyzed the microstructure in a hole-edge punched in HR 780HB steel. •Rotation rate fields revealed the stability of the initial texture components. •Heterogeneous effective stain was closely related to the KAM distribution. •VPSC model successfully simulated the deformation microtexture evolution.
Prillia Ayudia; Rachmat Haris; Mulyana Tatang
2017-01-01
PT Buana Intan Gemilang is a company engaged in textile industry. The curtain textile production need punching machine to control the fabric process. The operator still works manually so it takes high cost of electrical energy consumption. So to solve the problem can implement green manufacturing on punching machine. The method include firstly to identify the color by classifying the company into the black, brown, gray or green color categories using questionnaire. Secondly is improvement are...
Repetitive forging (RF) using inclined punches as a new bulk severe plastic deformation method
Energy Technology Data Exchange (ETDEWEB)
Babaei, A. [Department of Mechanical Engineering, University College of Engineering, University of Tehran, Tehran 11155-4563 (Iran, Islamic Republic of); Faraji, G., E-mail: ghfaraji@ut.ac.ir [Department of Mechanical Engineering, University College of Engineering, University of Tehran, Tehran 11155-4563 (Iran, Islamic Republic of); Department of Engineering Design and Manufacture, University of Malaya, 50603 Kuala Lumpur (Malaysia); Mashhadi, M.M. [Department of Mechanical Engineering, University College of Engineering, University of Tehran, Tehran 11155-4563 (Iran, Islamic Republic of); Hamdi, M. [Department of Engineering Design and Manufacture, University of Malaya, 50603 Kuala Lumpur (Malaysia)
2012-12-15
A new bulk severe plastic deformation method based on repetitive forging (RF) using inclined punches is proposed. This process consists of two half cycles. In the first half cycle, a square cross section deforms to parallelogram by forging with two inclined punches, and the parallelogram cross section is forged back to square using two flat punches in the second half cycle. This method was applied to commercially pure copper and significant grain refinement was achieved after four passes of RF. The results showed that significant improvement in the mechanical properties was obtained. Notable increase of yield and ultimate strengths corresponding to 358 MPa and 381 MPa after four passes of RF from the initial values of 121 MPa and 230.5 MPa is detectable. Microhardness increases to about 100 Hv after four passes of RF from the initial value of 53 Hv. Finite element (FE) results illustrate that RF is able to impose extremely high plastic strains to the materials. In the RF process, the processed samples have the same dimensions and geometry as those of the initial sample without any waste material and there is no need for back pressure.
Directory of Open Access Journals (Sweden)
Tsung-Mao Huang
2012-03-01
Full Text Available Dermatofibrosarcoma protuberans (DFSP is an uncommon soft-tissue tumor involving the dermis and subcutaneous tissue with a high local recurrence rate after standard excision. Mohs micrographic surgery offers a lower recurrence rate. However, the procedure requires multiple stages of excision with intraoperative histopathological mapping, which is time consuming and expensive. We report our experience of using circumferential scouting punch biopsy technique in five patients to determine in advance the resection margins for DFSP prior to wide excision. Multiple 4 mm punches, usually eight in number, were performed 1–2.5 cm around the palpable borders of DFSP to delineate the resection margins in five consecutive patients. Tumors were excised at a later date along the margin defined by these biopsies and the wounds were repaired with skin graft. The operation was completed in 2 hours in all cases excluding one that required frozen sections for deep margin. No recurrence was noted 2–10 years after the operations. The results suggest that circumferential scouting punch biopsies before wide excision may be an alternative method to define the resection margins for DFSP when Mohs surgery is not available.
Using Teamcenter engineering software for a successive punching tool lifecycle management
Blaga, F.; Pele, A.-V.; Stǎnǎşel, I.; Buidoş, T.; Hule, V.
2015-11-01
The paper presents studies and researches results of the implementation of Teamcenter (TC) integrated management of a product lifecycle, in a virtual enterprise. The results are able to be implemented also in a real enterprise. The product was considered a successive punching and cutting tool, designed to materialize a metal sheet part. The paper defines the technical documentation flow (flow of information) in the process of constructive computer aided design of the tool. After the design phase is completed a list of parts is generated containing standard or manufactured components (BOM, Bill of Materials). The BOM may be exported to MS Excel (.xls) format and can be transferred to other departments of the company in order to supply the necessary materials and resources to achieve the final product. This paper describes the procedure to modify or change certain dimensions of sheet metal part obtained by punching. After 3D and 2D design, the digital prototype of punching tool moves to following lifecycle phase of the manufacturing process. For each operation of the technological process the corresponding phases are described in detail. Teamcenter enables to describe manufacturing company structure, underlying workstations that carry out various operations of manufacturing process. The paper revealed that the implementation of Teamcenter PDM in a company, improves efficiency of managing product information, eliminating time working with search, verification and correction of documentation, while ensuring the uniqueness and completeness of the product data.
Energy Technology Data Exchange (ETDEWEB)
Isselin, J
2003-03-15
The aging of the electric production park implies an increasing need of knowledge concerning the evolution of the mechanical properties of its components. With regard to this problem, the availability in material is more and more small. This work proposes to characterize these properties through a mechanical test called Punch test. The main characteristic of this test is to use very small volume samples. The development of this test has been carried out by the study of a 15 MDV 4-05 steel coming from a steam drum of a thermal power plant after 145000 hours of service. At first, we have measured the influence of the parameters of this test. Then, the study has dealt more particularly on the transition temperature of the material. With the finite element simulation method, the strain hardening coefficient of the material has been determined. (O.M.)
Moving Griffith crack in an orthotropic strip with punches at boundary faces
Directory of Open Access Journals (Sweden)
S. Mukherjee
2005-01-01
Full Text Available Integral transform technique is employed to solve the elastodynamic problem of steady-state propagation of a Griffith crack centrally situated along the midplane of orthotropic strip of finite thickness 2h and subjected to point loading with centrally situated moving punches under constant pressure along the boundaries of the layer. The problem is reduced to the solution of a pair of simultaneous singular integral equations with Cauchy-type singularities which have finally been solved through the finite Hilbert transform technique. For large h, analytical expression for the stress intensity factor at the crack tip is obtained. Graphical plots of the numerical results are also presented.
Contact stresses by rounded punch subject to axial and transverse shear
Energy Technology Data Exchange (ETDEWEB)
Kim, Hyung Kyu [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)
1999-05-01
Contact shear stresses by rounded punch were evaluated numerically. Numerical program was successfully implemented by using an influence function method. To simulate the physical fretting problem, a closed load path of shear was considered. The influence functions on surface displacements fo both axial and transverse direction were calculated using a triangular shear traction element. Behaviour of the contact surface, such as stick and slip region during the load path was investigated together with compliance change. Irreversibility of the shear stress was shown. The importance and the utilization of the present research were discussed for analyzing the material failure induced by contact such as fretting wear and fatigue.
Contact stresses by rounded punch subject to axial and transverse shear
International Nuclear Information System (INIS)
Kim, Hyung Kyu
1999-01-01
Contact shear stresses by rounded punch were evaluated numerically. Numerical program was successfully implemented by using an influence function method. To simulate the physical fretting problem, a closed load path of shear was considered. The influence functions on surface displacements fo both axial and transverse direction were calculated using a triangular shear traction element. Behaviour of the contact surface, such as stick and slip region during the load path was investigated together with compliance change. Irreversibility of the shear stress was shown. The importance and the utilization of the present research were discussed for analyzing the material failure induced by contact such as fretting wear and fatigue
Backward can extrusion with conical,rotating punch as a cold forging tribology test
DEFF Research Database (Denmark)
Ceron, Ermanno; Bay, Niels; Tetsuo, A.
2011-01-01
with an analysis of the sliding velocity distribution along the punch nose. The latter is determined by FE analysis of the test. Results show friction stress for unalloyed low C-steel provided with different types of lubricants, e.g. phosphate coating plus soap, phosphate coating plus MoS2 and single bathe...... lubrication with PULS. The new test is so severe, that it is possible to break down the best lubrication systems for cold forging, such as phosphate coating plus soap and MoS2....
Tooling solutions for sheet metal forming and punching of lean duplex stainless steel
DEFF Research Database (Denmark)
Wadman, Boel; Madsen, Erik; Bay, Niels
2012-01-01
.4509 and lean duplex EN1.4162 in a production designed for austenitic stainless steels, such as EN1.4301 and 1.4401. The result is a guideline that summarizes how stainless material properties may affect tool degradation, and suggests tool solutions for reduced production disturbances and tool maintenance cost.......For producers of advanced stainless components the choice of stainless material influences not only the product properties, but also the tooling solution for sheet metal stamping. This work describes how forming and punching tools will be affected when introducing the stainless alloys ferritic EN1...
Strain gradient effects in periodic flat punch indenting at small scales
DEFF Research Database (Denmark)
Nielsen, Kim Lau; Niordson, Christian Frithiof; Hutchinson, J. W.
2014-01-01
Experiments on soft polycrystalline aluminum have yielded evidence that, besides the required punch load, both the size and shape of imprinted features are affected by the scale of the set-up, e.g. substantial details are lost when the characteristic length is on the order of 10μm. The objective...... are employed. During a largely non-homogeneous deformation, the material is forced up in between the indenters so that an array of identical imprinted features is formed once the tool is retreated. It is confirmed that the additional hardening owing to plastic strain gradients severely affects both the size...
Directory of Open Access Journals (Sweden)
T. S. Ozsahin
2013-01-01
Full Text Available The frictionless contact problem for an elastic layer resting on an elastic half plane is considered. The problem is solved by using the theory of elasticity and integral transformation technique. The compressive loads P and Q (per unit thickness in direction are applied to the layer through three rigid flat punches. The elastic layer is also subjected to uniform vertical body force due to effect of gravity. The contact along the interface between elastic layer and half plane is continuous, if the value of the load factor, λ, is less than a critical value, . In this case, initial separation loads, and initial separation points, are determined. Also the required distance between the punches to avoid any separation between the punches and the elastic layer is studied and the limit distance between punches that ends interaction of punches is investigated for various dimensionless quantities. However, if tensile tractions are not allowed on the interface, for the layer separates from the interface along a certain finite region. Numerical results for distance determining the separation area, vertical displacement in the separation zone, contact stress distribution along the interface between elastic layer and half plane are given for this discontinuous contact case.
Mitsunaga, Erin M
2006-05-01
During the Korean War, International Business Machines (IBM) punch cards were created for every individual involved in military combat. Each card contained all pertinent personal information about the individual and was utilized to keep track of all soldiers involved. However, at present, all of the information known about these punch cards reveals only their format and their significance; there is little to no information on how these cards were created or how to interpret the information contained without the aid of the computer system used during the war. Today, it is believed there is no one available to explain this computerized system, nor do the original computers exist. This decode strategy is the result of an attempt to decipher the information on these cards through the use of all available medical and dental records for each individual examined. By cross-referencing the relevant personal information with the known format of the cards, a basic guess-and-check method was utilized. After examining hundreds of IBM punch cards, however, it has become clear that the punch card method of recording information was not infallible. In some cases, there are gaps of information on cards where there are data recorded on personal records; in others, information is punched incorrectly onto the cards, perhaps as the result of a transcription error. Taken all together, it is clear that the information contained on each individual's card should be taken solely as another form of personal documentation.
Kedous-Lebouc, A.; Messal, O.; Youmssi, A.
2017-03-01
Mechanical punching of electrical steels causes a degradation of their magnetic characteristics which can extend several millimeters from the cut edge. So, in the field of industrial applications, particularly that of small electrical machines, the stator core made of rigid and thin teeth would be subject to more losses. Thus, this topic of the effect of punching has to be submitted to further deep characterization and development in order to give some insight into the different mechanisms. In this framework, this paper evaluates the combined effect of punching and frequency on the magnetization curve and iron losses in thin SiFe and CoFe soft magnetic sheets. These alloys are typically suitable for the manufacture of high-speed electrical machines used in on board applications (aircraft power generators, automotive, etc). Two SiFe alloys and a CoFe alloy have been investigated. First, different rectangular samples of variable width (15, 10, 5, 3 mm) have been industrially punched. Then, a dedicated magnetic characterization has been made, using basically a mini-Epstein frame. Measurements have been performed from 50 Hz to 1 kHz and from 0.3 T to near saturation. Both rolling and transverse directions have been considered. Finally, a first attempt to predict the degradation due to the punching is presented. A useful description of the magnetic permeability as a function of B and f is given and the degradation parameters are estimated based on the knowledge of the reference permeability.
Energy Technology Data Exchange (ETDEWEB)
Kedous-Lebouc, A. [Univ. Grenoble Alpes, G2Elab, F-38000 Grenoble, France — CNRS, G2Elab, F-38000 Grenoble (France); Messal, O., E-mail: oualid.messal@g2elab.grenoble-inp.fr [Univ. Grenoble Alpes, G2Elab, F-38000 Grenoble, France — CNRS, G2Elab, F-38000 Grenoble (France); Youmssi, A. [Université de N’gaoundéré, BP. 455 N’Gaoundéré (Cameroon)
2017-03-15
Mechanical punching of electrical steels causes a degradation of their magnetic characteristics which can extend several millimeters from the cut edge. So, in the field of industrial applications, particularly that of small electrical machines, the stator core made of rigid and thin teeth would be subject to more losses. Thus, this topic of the effect of punching has to be submitted to further deep characterization and development in order to give some insight into the different mechanisms. In this framework, this paper evaluates the combined effect of punching and frequency on the magnetization curve and iron losses in thin SiFe and CoFe soft magnetic sheets. These alloys are typically suitable for the manufacture of high-speed electrical machines used in on board applications (aircraft power generators, automotive, etc). Two SiFe alloys and a CoFe alloy have been investigated. First, different rectangular samples of variable width (15, 10, 5, 3 mm) have been industrially punched. Then, a dedicated magnetic characterization has been made, using basically a mini-Epstein frame. Measurements have been performed from 50 Hz to 1 kHz and from 0.3 T to near saturation. Both rolling and transverse directions have been considered. Finally, a first attempt to predict the degradation due to the punching is presented. A useful description of the magnetic permeability as a function of B and f is given and the degradation parameters are estimated based on the knowledge of the reference permeability.
"One can't shake off the women": images of sport and gender in Punch, 1901-10.
Constanzo, Marilyn
2002-01-01
Examining the manner in which the popular press portrayed middle-class Edwardian women's activity in sport provides insight into the social liberation of English women. The popular middle-class British journal Punch included thousands of images of sportswomen. Despite the misogynistic satirizing of inept women, Punch's cartoons and articles depict distinct changes in women's behavior and social expectations that are linked to their increasing involvement in sport. By engaging in sport, women unconsciously challenged and permanently altered the pervasive middle-class Victorian ideology. The contents of Punch suggests that middle-class women's participation in sport, though perhaps begun in a conservative manner, completely altered and expanded their social role and changed the traditional image of womanhood.
Fabrikant, I.; Karapetian, E.; Kalinin, S. V.
2018-02-01
We consider the problem of an arbitrary shaped rigid punch pressed against the boundary of a transversely isotropic half-space and interacting with an arbitrary flat crack or inclusion, located in the plane parallel to the boundary. The set of governing integral equations is derived for the most general conditions, namely the presence of both normal and tangential stresses under the punch, as well as general loading of the crack faces. In order to verify correctness of the derivations, two different methods were used to obtain governing integral equations: generalized method of images and utilization of the reciprocal theorem. Both methods gave the same results. Axisymmetric coaxial case of interaction between a rigid inclusion and a flat circular punch both centered along the z-axis is considered as an illustrative example. Most of the final results are presented in terms of elementary functions.
Directory of Open Access Journals (Sweden)
Prillia Ayudia
2017-01-01
Full Text Available PT Buana Intan Gemilang is a company engaged in textile industry. The curtain textile production need punching machine to control the fabric process. The operator still works manually so it takes high cost of electrical energy consumption. So to solve the problem can implement green manufacturing on punching machine. The method include firstly to identify the color by classifying the company into the black, brown, gray or green color categories using questionnaire. Secondly is improvement area to be optimized and analyzed. Improvement plan at this stage that is focusing on energy area and technology. Thirdly is process applies by modifying the technology through implementing automation system on the punching machine so that there is an increase of green level on the process machine. The result obtained after implement the method can save cost on electrical energy consumption in the amount of Rp 1.068.159/day.
Design of punching shear for prestressed slabs with unbonded tendons on internal columns
Directory of Open Access Journals (Sweden)
L. A. R. Luchi
Full Text Available ABSTRACT This paper is related to the punching shear in prestressed slabs with unbonded tendons for interior columns calculated by the codes ABNT NBR 6118:2007, ABNT NBR 6118:2014, EN 1992-1-1:2004 e ACI 318-11. To calculate the punching shear resistance the formulations of the NBR 6118:07, effective until April/2014, did not consider the compression of the concrete in the plane of the slab, due to prestressing. Just the inclined components of some tendons were considered for total load applied relief, but this fact did not generate a significant difference, compared to reinforced concrete, because the inclination angle is very close to zero. The American and European provisions consider a portion related to the compression of the concrete in the planeof the slab. Differences in the results obtained by the four design codes will be exposed, showing that the EC2:04 and the NBR6118:14 achieved the best results.
Optimal design of a main driving mechanism for servo punch press based on performance atlases
Zhou, Yanhua; Xie, Fugui; Liu, Xinjun
2013-09-01
The servomotor drive turret punch press is attracting more attentions and being developed more intensively due to the advantages of high speed, high accuracy, high flexibility, high productivity, low noise, cleaning and energy saving. To effectively improve the performance and lower the cost, it is necessary to develop new mechanisms and establish corresponding optimal design method with uniform performance indices. A new patented main driving mechanism and a new optimal design method are proposed. In the optimal design, the performance indices, i.e., the local motion/force transmission indices ITI, OTI, good transmission workspace good transmission workspace(GTW) and the global transmission indices GTIs are defined. The non-dimensional normalization method is used to get all feasible solutions in dimensional synthesis. Thereafter, the performance atlases, which can present all possible design solutions, are depicted. As a result, the feasible solution of the mechanism with good motion/force transmission performance is obtained. And the solution can be flexibly adjusted by designer according to the practical design requirements. The proposed mechanism is original, and the presented design method provides a feasible solution to the optimal design of the main driving mechanism for servo punch press.
Treatment of a Refractory Skin Ulcer Using Punch Graft and Autologous Platelet-Rich Plasma
Directory of Open Access Journals (Sweden)
Mauro Carducci
2016-01-01
Full Text Available Background. Chronic ulceration of the lower legs is a relatively common condition amongst adults: one that causes pain and social distress and results in considerable healthcare and personal costs. The technique of punch grafting offers an alternative approach to the treatment of ulcers of the lower limbs. Objective. Combining platelet-rich plasma and skin graft enhances the efficacy of treating chronic diabetic wounds by enhancing healing rate and decreasing recurrence rate. Platelet-rich plasma could, by stimulating dermal regeneration, increase the take rate after skin grafting or speed up reepithelialization. Methods and Materials. The ulcer was prepared by removing fibrin with a curette and the edges of the ulcer were freshened. The platelet-rich plasma has been infiltrated on the bottom and edges of the ulcer. The punch grafts were placed in 5 mm holes arranged. The ulcer was medicated with hydrogel and a pressure dressing was removed after 8 days. Results. After a few days the patient did not report more pain. Granulation tissue appeared quickly between implants. Most of the grafts were viable in 2-3 weeks. The grafts gradually came together to close the ulcer and were completed in four months.
Studying the sensor response in the punch-through-protection region
Poley, Anne-luise; The ATLAS collaboration
2017-01-01
For the Phase-II Upgrade of the ATLAS detector, a new, all-silicon tracker will be constructed in order to cope with the increased track density and radiation level of the High Luminosity Large Hadron Collider. While silicon strip sensors are designed to minimise the fraction of dead material and maximise the active area of a sensor, concessions must be made to the requirements of operating a sensor in a particle physics detector. Sensor geometry features like the punch-through protection deviate from the standard sensor architecture and thereby affect the charge collection in that area. In order to study the signal collection of silicon strip sensors over their punch-through-protection area, ATLAS silicon strip sensors were scanned with a micro-focused X-ray beam at the Diamond Light Source. Due to the highly focused X-ray beam (2 × 3 µm) and the short average path length of an electron after interaction with an X-ray photon (≤ 2 μm), local signal collection in different sensor areas can be studied with...
Effects of laser power density and initial grain size in laser shock punching of pure copper foil
Zheng, Chao; Zhang, Xiu; Zhang, Yiliang; Ji, Zhong; Luan, Yiguo; Song, Libin
2018-06-01
The effects of laser power density and initial grain size on forming quality of holes in laser shock punching process were investigated in the present study. Three different initial grain sizes as well as three levels of laser power densities were provided, and then laser shock punching experiments of T2 copper foil were conducted. Based upon the experimental results, the characteristics of shape accuracy, fracture surface morphology and microstructures of punched holes were examined. It is revealed that the initial grain size has a noticeable effect on forming quality of holes punched by laser shock. The shape accuracy of punched holes degrades with the increase of grain size. As the laser power density is enhanced, the shape accuracy can be improved except for the case in which the ratio of foil thickness to initial grain size is approximately equal to 1. Compared with the fracture surface morphology in the quasistatic loading conditions, the fracture surface after laser shock can be divided into three zones including rollover, shearing and burr. The distribution of the above three zones strongly relates with the initial grain size. When the laser power density is enhanced, the shearing depth is not increased, but even diminishes in some cases. There is no obvious change of microstructures with the enhancement of laser power density. However, while the initial grain size is close to the foil thickness, single-crystal shear deformation may occur, suggesting that the ratio of foil thickness to initial grain size has an important impact on deformation behavior of metal foil in laser shock punching process.
A DLC-Punch Array to Fabricate the Micro-Textured Aluminum Sheet for Boiling Heat Transfer Control
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Tatsuhio Aizawa
2018-03-01
Full Text Available A diamond-like carbon (DLC film, coated on an SKD11 (alloy tool steel substrate, was shaped by plasma oxidation to form an assembly of DLC macro-pillars and to be used as a DLC-punch array that is micro-embossed into aluminum sheets. First, the SKD11 steel die substrate was prepared and DLC-coated to have a film thickness of 10 μm. This DLC coating worked as a punch material. The two-dimensional micro-patterns were printed onto this DLC film by maskless lithography. The unprinted DLC films were selectively removed by plasma oxidation to leave the three-dimensional DLC-punch array on the SKD11 substrate. Each DLC punch had a head of 3.5 μm × 3.5 μm and a height of 8 μm. This DLC-punch array was fixed into the cassette die set for a micro-embossing process using a table-top servo-stamper. Furthermore, through numerically controlled micro-embossing, an alignment of rectangular punches was transcribed into a micro-cavity array in the aluminum sheet. The single micro-cavity had a bottom surface of 3.2 μm × 3.2 μm and an average depth of 7.5 μm. A heat-transfer experiment in boiling water was also performed to investigate the effect of micro-cavity texture on bubbling behavior and the boiling curve.
Hukkanen, Esa; Häkkinen, Keijo
2017-06-01
Seven, male, national-level boxers (age, 20.3 ± 2.7 years; height, 1.80 ± 0.06 m; mass, 73.8 ± 11.1 kg) participated in this study to investigate the effects of sparring on reaction time and punch force of straight punches measured during the precompetition and competition periods. Heart rate and blood lactate concentrations were also monitored. Sparring load was chosen in accordance with the current rules: 3 × 3-minute bouts with 1-minute break in between. Reaction time of rear straight lengthened (p boxing-specific and explosive strength training.
Fongers, A.; Wolkerstorfer, A.; Nieuweboer-Krobotova, L.; Krawczyk, P.; Tóth, G. G.; van der Veen, J. P. W.
2009-01-01
Background Punch grafting is a simple and frequently used technique for the treatment of stable vitiligo, resistant to medical therapy. However, studies reporting long-term results are exceptional. Objectives To evaluate the long-term results of 2-mm punch grafting in patients with vitiligo vulgaris
Fongers, A.; Wolkerstorfer, A.; Nieuweboer-Krobotova, L.; Krawczyk, P.; Toth, G. G.; van der Veen, J. P. W.
Background Punch grafting is a simple and frequently used technique for the treatment of stable vitiligo, resistant to medical therapy. However, studies reporting long-term results are exceptional. Objectives To evaluate the long-term results of 2-mm punch grafting in patients with vitiligo vulgaris
Fongers, A.; Wolkerstorfer, A.; Nieuweboer-Krobotova, L.; Krawczyk, P.; Toth, G. G.; van der Veen, J. P. W.
2009-01-01
Background Punch grafting is a simple and frequently used technique for the treatment of stable vitiligo, resistant to medical therapy. However, studies reporting long-term results are exceptional. Objectives To evaluate the long-term results of 2-mm punch grafting in patients with vitiligo vulgaris
International Nuclear Information System (INIS)
Cao, Hongzhi; Hao, Linpo; Yi, Jingwen; Zhang, Xianglin; Luo, Zhonghan; Chen, Shenglin; Li, Rongfeng
2016-01-01
The main purpose of this paper is to investigate the influence of punching process on residual stress and magnetic domain structure. The residual stress in non-oriented silicon steel after punching process was measured by nanoindentation. The maximum depth was kept constant as 300 nm during nanoindentation. The material around indentation region exhibited no significant pile-up deformation. The calculation of residual stress was based on the Suresh theoretical model. Our experimental results show that residual compressive stress was generated around the sheared edge after punching. The width of residual stress affected zone by punching was around 0.4–0.5 mm. After annealing treatment, the residual stress was significantly decreased. Magnetic domain structure was observed according to the Bitter method. The un-annealed sample exhibited complicated domain patterns, and the widths of the magnetic domains varied between 3 µm and 8 µm. Most of the domain patterns of the annealed sample were 180°-domains and 90°-domains, and the widths of the domains decreased to 1–3 µm. - Highlights: • The residual stress distribution on sheared edge was measured. • The residual compressive stress was generated around the sheared edge. • The width of residual stress affected zone was about 0.4–0.5 mm. • The shape and width of the domain structure would be changed by annealing.
International Nuclear Information System (INIS)
Valenca, M.M.; Negro Vilar, A.
1991-01-01
In order to demonstrate an experimental method to study neuropeptide distribution in the central nervous system, the content of beta-endorphin present in several brain regions was determined by the combined use of radioimmunoassay with the neuroanatomic punch technique described by Palkovits. (author)
DEFF Research Database (Denmark)
Rasmussen, Jesper; Griepentrog, Hans W.; Nielsen, Jon
2012-01-01
in sugar beet and carrot crops showed no synergistic effects between plant establishment procedures and selectivity of post-emergence weed harrowing. Even if punch planting and automated intelligent rotor tine cultivation were not combined, the results indicated that there was no reason to believe...... that mainly work through soil burial....
Assessment of strength characteristics of Al2024 ECAP metal using small punch testing
International Nuclear Information System (INIS)
Ma, Young Wha; Choi, Jeong Woo; Yoon, Kee Bong; Kim, Seon Hwa
2006-01-01
When subjected to severe shear deformation by ECAP, microstructure of Al2024 becomes extremely refined. To measure the strength of that, Small Punch(SP) testing method was adopted as a substitute for the conventional uniaxial tensile testing because the size of material processed by ECAP were limited to ψ12 mm in transverse direction. SP tests were performed with specimens in longitudinal and transverse directions of Al2024 ECAP metal. For comparing the strength values with those assessed by SP tests, uniaxial tensile tests were also conducted with specimens in longitudinal direction. Failure surfaces of the tested SP specimens showed that failure mode was shear deformation and Al2024 ECAP metal has an anisotropy in strength. Thus, conventional equations proposed for assessing the strength characteristics were improper to assess those of Al2024 ECAP metal. In this paper a way of assessing the strength of Al2024 ECAP metal was proposed and was proven to be effective
Study of the mechanical properties of the electric power station components: the punch test
International Nuclear Information System (INIS)
Isselin, J.
2003-03-01
The aging of the electric production park implies an increasing need of knowledge concerning the evolution of the mechanical properties of its components. With regard to this problem, the availability in material is more and more small. This work proposes to characterize these properties through a mechanical test called Punch test. The main characteristic of this test is to use very small volume samples. The development of this test has been carried out by the study of a 15 MDV 4-05 steel coming from a steam drum of a thermal power plant after 145000 hours of service. At first, we have measured the influence of the parameters of this test. Then, the study has dealt more particularly on the transition temperature of the material. With the finite element simulation method, the strain hardening coefficient of the material has been determined. (O.M.)
From Punched Cards to "Big Data": A Social History of Database Populism
Directory of Open Access Journals (Sweden)
Kevin Driscoll
2012-08-01
Full Text Available Since the diffusion of the punched card tabulator following the 1890 U.S. Census, mass-scale information processing has been alternately a site of opportunity, ambivalence and fear in the American imagination. While large bureaucracies have tended to deploy database technology toward purposes of surveillance and control, the rise of personal computing made databases accessible to individuals and small businesses for the first time. Today, the massive collection of trace communication data by public and private institutions has renewed popular anxiety about the role of the database in society. This essay traces the social history of database technology across three periods that represent significant changes in the accessibility and infrastructure of information processing systems. Although many proposed uses of "big data" seem to threaten individual privacy, a largely-forgotten database populism from the 1970s and 1980s suggests that a reclamation of small-scale data processing might lead to sharper popular critique in the future.
The small punch assessment of toughness losses in low alloy steels
Energy Technology Data Exchange (ETDEWEB)
Bulloch, J.H. [ESB, Power Generation, Dublin (Ireland)
1998-12-31
The presentation deals at length with the relationship between the Small Punch, SP, test transition temperature Tsp, behaviour and those displayed by the conventional Charpy Fracture Appearance Transition Temperature, FATT, obtained from large test specimens. Essentially it was demonstrated that the total test temperature range trends could reasonably be described by a non-linear expression such as FATT varied inversely with the square of the Tsp. Finally when the Tsp against FATT trends were separated into different steel classes an encouraging picture emerged inasmuch that a reasonable amount of data exhibited good agreement with the predicted effects of grain size. Fractographic details were also discussed and strong effects of strain or loading rates were identified. (orig.) 19 refs.
Finite-Element Modeling of Timber Joints with Punched Metal Plate Fasteners
DEFF Research Database (Denmark)
Ellegaard, Peter
2006-01-01
The focus of this paper is to describe the idea and the theory behind a finite-element model developed for analysis of timber trusses with punched metal plate fasteners (nail plates). The finite-element model includes the semirigid and nonlinear behavior of the joints (nonlinear nail and plate...... elements) and contact between timber beams, if any (bilinear contact elements). The timber beams have linear-elastic properties. The section forces needed for design of the joints are given directly by the finite-element model, since special elements are used to model the nail groups and the nail plate...... the behavior of the joints very well at lower load levels. At higher load levels the stiffness is overestimated due to development of cracks in the timber and the linear-elastic timber properties in the finite-element model....
The small punch assessment of toughness losses in low alloy steels
Energy Technology Data Exchange (ETDEWEB)
Bulloch, J H [ESB, Power Generation, Dublin (Ireland)
1999-12-31
The presentation deals at length with the relationship between the Small Punch, SP, test transition temperature Tsp, behaviour and those displayed by the conventional Charpy Fracture Appearance Transition Temperature, FATT, obtained from large test specimens. Essentially it was demonstrated that the total test temperature range trends could reasonably be described by a non-linear expression such as FATT varied inversely with the square of the Tsp. Finally when the Tsp against FATT trends were separated into different steel classes an encouraging picture emerged inasmuch that a reasonable amount of data exhibited good agreement with the predicted effects of grain size. Fractographic details were also discussed and strong effects of strain or loading rates were identified. (orig.) 19 refs.
Performance improvement in a tubular heat exchanger by punched delta-winglet vortex generators
Khanoknaiyakarn, C.; Promvonge, P.; Thianpong, C.; Skullong, S.
2018-01-01
A novel tubular heat exchanger incorporated with punched delta-winglet vortex generators (called perforated delta-winglet vortex generator, P-DWVG) is proposed for improving its thermal performance and energy saving. The P-DWVG elements are punched out from a straight tape having its width nearly equal to the tube diameter before insertion. The main aim at employing the P-DWVG insert is to produce counter-rotating vortices along the tube to promote turbulence intensity inside as well as to transport the cold fluid at the central core to the near-wall regions. The experiment was performed to study thermal behaviors in a uniform heat-fluxed tube inserted with P-DWVGs. The P-DWVGs with the attack angle of 45° were mounted periodically with three different blockage ratios (BR = 0.1, 0.2 and 0.3) and two pitch ratios (PR = 2 and 3). Air as the test fluid was varied to obtain turbulent airflow for Reynolds number (Re) in a range of 4,150-25,500. The experimental results show that the P-DWVG provides a considerable increase in the rate of heat transfer around 3.1-4.01 times whereas friction factor increases around 11.44- 34.23 times higher than the plain tube. To assess the real benefits of P-DWVGs, thermal performance factor (TEF) is examined and in the range of 1.39-1.48 where its maximum is at BR = 0.1 and PR = 2.
Badal Tejedor, Maria; Nordgren, Niklas; Schuleit, Michael; Millqvist-Fureby, Anna; Rutland, Mark W
2017-11-21
Adhesion of the powders to the punches is a common issue during tableting. This phenomenon is known as sticking and affects the quality of the manufactured tablets. Defective tablets increase the cost of the manufacturing process. Thus, the ability to predict the tableting performance of the formulation blend before the process is scaled-up is important. The adhesive propensity of the powder to the tableting tools is mostly governed by the surface-surface adhesive interactions. Atomic force microscopy (AFM) colloidal probe is a surface characterization technique that allows the measurement of the adhesive interactions between two materials of interest. In this study, AFM steel colloidal probe measurements were performed on ibuprofen, MCC (microcrystalline cellulose), α-lactose monohydrate, and spray-dried lactose particles as an approach to modeling the punch-particle surface interactions during tableting. The excipients (lactose and MCC) showed constant, small, attractive, and adhesive forces toward the steel surface after a repeated number of contacts. In comparison, ibuprofen displayed a much larger attractive and adhesive interaction increasing over time both in magnitude and in jump-in/jump-out separation distance. The type of interaction acting on the excipient-steel interface can be related to a van der Waals force, which is relatively weak and short-ranged. By contrast, the ibuprofen-steel interaction is described by a capillary force profile. Even though ibuprofen is not highly hydrophilic, the relatively smooth surfaces of the crystals allow "contact flooding" upon contact with the steel probe. Capillary forces increase because of the "harvesting" of moisture-due to the fast condensation kinetics-leaving a residual condensate that contributes to increase the interaction force after each consecutive contact. Local asperity contacts on the more hydrophilic surface of the excipients prevent the flooding of the contact zone, and there is no such adhesive
Abdullah, A. B.; Zain, M. S. M.; Abdullah, M. S.; Samad, Z.
2017-07-01
Structural materials, such as composite panels, must be assembled, and such panels are typically constructed via the insertion of a fastener through a drilled hole. The main problem encountered in drilling is delamination, which affects assembly strength. The cost of drilling is also high because of the severe wear on drill bits. The main goal of this research is to develop a new punching method as an alternative to drilling during hole preparation. In this study, the main objective is to investigate the effect of different puncher profiles on the quality of holes punched into carbon fiber reinforcement polymer (CFRP) composite panels. Six types of puncher profiles were fabricated with minimum die clearance (1%), and two quality aspects, namely, incomplete shearing and delamination factor, were measured. The conical puncher incurred the least defects in terms of delamination and yielded an acceptable amount of incomplete shearing in comparison with the other punchers.
Directory of Open Access Journals (Sweden)
O. S. PAIVA
Full Text Available Experimental evidence indicates that both the column rectangularity index and the boundary conditions of the connection may affect the ultimate punching resistance. This paper presents general aspects of these topics and, through the analysis of experimental results of tests on 131 slabs, evaluates the accuracy and suitability of recommendations presented by ABNT NBR 6118, Eurocode 2, ACI 318 and fib Model Code 2010. Experimental results showed that the security level of normative estimates trend to reduce as the column rectangularity increases, and in some cases, the punching resistance was overestimated. Finally, adjustments are suggested in equations presented by NBR 6118 and MC2010 in order to eliminate this trend of unsafe results.
Zheng, Naiyu; Yuan, Long; Ji, Qin C; Mangus, Heidi; Song, Yan; Frost, Charles; Zeng, Jianing; Aubry, Anne-Françoise; Arnold, Mark E
2015-04-15
Apixaban (Eliquis™) was developed by Bristol-Myers Squibb (BMS) and Pfizer to use as an antithrombotic/anticoagulant agent and has been recently approved for the prevention of stroke and systemic embolism in patients with nonvalvular atrial fibrillation. A clinical study of apixaban, sponsored by BMS and Pfizer, included a pilot exploratory portion to evaluate the potential for future drug concentration monitoring using dried blood spot (DBS) sample collection. For DBS sample collection, a fixed blood volume was dispensed onto a DBS card by either regular volumetric pipette (venous blood collection) or capillary dispenser (finger prick blood collection). A 96-well semi-automated liquid-liquid extraction sample preparation procedure was developed to provide clean extracts for UHPLC-MS/MS quantitation. Assays using both partial-spot center punch and whole spot punch were developed and validated. The linear dynamic ranges for all the analyses were from 0.5 to 500 ng/mL. The coefficient of determination (r(2)) values was >0.9944 for all the validation runs. For the center punch approach, the intra-assay precision (%CV) was within 4.4% and inter-assay precision was within 2.6%. The assay accuracy, expressed as %Dev., was within ± 5.4% of the nominal concentrations. One accuracy and precision run was performed using the whole spot approach, the intra-assay precision (%CV) was within 7.1% and the accuracy was within ± 8.0% of the nominal concentrations. In contrast to the center punch approach, the whole spot approach eliminated the effect of hematocrit and high lipids on the analysis of apixaban in human DBS when an accurate sample blood volume was collected on DBS cards. Copyright © 2015 Elsevier B.V. All rights reserved.
International Nuclear Information System (INIS)
Duffey, T.A.; Sutherland, S.H.; Cheresh, M.
1980-01-01
Analytical solutions and experimental results are presented for the response of foundation-backed plates to static and dynamic punch loading. Tests were performed on polyurethane foam-backed and unbacked plates; plates were centrally loaded over a range-in plastic deformations up to complete failure. This is part of an attempt to understand the puncture resistance of the sidewalls of containers used to ship hazardous wastes
Directory of Open Access Journals (Sweden)
Kut S.
2015-09-01
Full Text Available This paper presents the results of the numerical analysis and experimental research of the forming process of aviation drawpiece made from 0.6 mm thick Inconel 625 sheet metal. First phase of testing was conducted using rigid steel tools for drawpiece forming. Results of conducted simulations show that during rigid tool forming, the middle of the drawpiece losses stability. In consequence, rigid tool forming leads to the formation of unacceptable wrinkles on the drawpiece. Subsequent experimental research confirmed wrinkles of the metal drawpiece in this area. It was assumed that in order to eliminate this negative phenomenon, minor changes in technology and tool construction would have to be made. The drawpiece will be shaped by means of a flexible tool, than re-shaped using rigid tools. In the second phase of the research, tooling design changes have been made. They consisted of replacing the steel punch with a specially designed stamp susceptible for deformation. FEM numerical simulations were performed for flexible punch forming made of polyurethane elastomer with different hardness (50, 70, 85 and 90 Sh A. On their basis, the effect on the mechanical characteristics of the elastomeric drawing process and the formation of wrinkles was shown. They can be effectively eliminated by the use of a punch with hardness of 90 Sh A, which has also been confirmed by experimental research. In addition, the paper presents a comparative analysis of the deformations in selected actual drawpiece areas and in the elastomeric punch with hardness 90 Sh A computer model. The actual drawpiece deformation schedule and the values were determined using photogrammetric system Argus v.6.3., while the computer modeled drawpiece was based on FEM calculations performed in the MARC / Mentat system. In conclusion the difficulties as well as the advantages and disadvantages in determining the deformation of sheet metal parts were indicated using photogrammetric system
Bonilla, Alfonso; Magri, Carlos; Juan, Eulalia
To compare the punch technique and linear incision with soft tissue reduction for the placement of auditory osseointegrated implants (AOI) and analyze results of osseointegration obtained with the punch technique as measured with the Implant Stability Quotient (ISQ). Case review of 34 patients who received auditory osseointegrated implants between January 2010 and July 2015 and were divided into two groups according to the surgical technique: 18 with the punch technique (PT) and 16 with the linear incision technique (LI). Minimum follow-up was four months (mean: 24 months; range 4-64 months). Included in the analysis were patient profiles and records of the demographic data, surgical indications, surgical technique, implant placement, surgical time, intraoperative complications, as well as postsurgical complications (Holgers classification) and implant stability quotients (ISQ). Use of larger abutments was significantly greater in the PT group (PT, 10mm; LI, 6mm, p<0.001). The PT technique resulted in a shorter procedure than the LI (PT, 20min; LI, 45min, p<0.001). Holgers classification scores identified significantly fewer skin complications one week after surgery for the PT group; however, only small differences were seen between the two groups at the one- and three-month control visits. As shown for our cohort, the punch technique for surgical placement of AOI is faster and presents fewer immediate postoperative complications when compared to the linear incision technique. The clinical application of the ISQ is a useful, easy method to demonstrate the status of osseointegration and, thus, the stability of the device. Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Otorrinolaringología y Cirugía de Cabeza y Cuello. All rights reserved.
Directory of Open Access Journals (Sweden)
D. C. Oliveira
Full Text Available The structural behavior and the ultimate punching shear resistance of internal reinforced concrete flat slab-column connections, with one hole adjacent to the column, with or without flexural moment transfer of the slab to the column was investigated. Main variables were: the existence whether or not hole, flexural reinforcement layout and ratio, the direction and sense of the moment transferred and the eccentricity of the load (M (moment transferred to column / V (shear ratio at the connection - 0,50 m or 0,25 m. Seven internal slab-column joining were tested and ultimate loads, cracking, deflections, concrete and reinforcement strains were analyzed. The existence of hole adjacent to the smaller column dimension, the hole dimension, flexural reinforcement rate and placing, the variation of relation Mu/Vu in function of the load, and, than, of eccentricity of the load, influenced the slabs behavior and rupture load. Test results were compared with the estimations from CEB-FIP/MC1990 [7], EC2/2004 [12], ACI-318:2011 [1] and NBR 6118:2007 [5]. ACI [1] and EC2 [12] presented most conservative estimates, although have presented some non conservative estimates. Brazilian NBR [5], even though being partly based in EC2 [12], presented smaller conservative estimates and more non conservative estimates. A modification on all codes is proposed for taking in account the moment caused by the eccentricity at the critical perimeter for slabs with holes.
Creep damage evaluation of low alloy steel weld joint by small punch creep testing
International Nuclear Information System (INIS)
Nishioka, Tomoya; Sawaragi, Yoshiatsu; Uemura, Hiromi
2013-01-01
The effect of sampling location on SPC (Small Punch Creep) tests were investigated for weld joints to establish evaluation method of Type IV creep behavior. The SPC specimen shape was 10mm diameter and 0.5mm thick round disc prepared from weld joints of 2.25Cr-1Mo low alloy steel. It was found that the center of SPC specimen should be 2mm apart from the weld interface as the recommended sampling location. Creep damage was imposed for large weld joint specimens by axial creep loading at 620degC, 52MPa with the interrupted time fraction of 0.34, 0.45, 0.64 and 0.82.SPC samples were prepared from those damaged specimens following the recommended way described in this paper. Among the various SPC tests conducted, good relationships were found for the test condition of 625degC, 200N. Namely, good relationships were obtained both between minimum deflection rate and creep life fraction, and between rupture time and creep life fraction. Consequently, creep life assessment of Type IV fracture by SPC tests could be well conducted using the sampling location and the test condition recommended in this paper. (author)
A creep life assessment method for boiler pipes using small punch creep test
International Nuclear Information System (INIS)
Izaki, Toru; Kobayashi, Toshimi; Kusumoto, Junichi; Kanaya, Akihiro
2009-01-01
The small punch creep (SPC) test is considered as a highly useful method for creep life assessment for high temperature plant components. SPC uses miniature-sized specimens and does not cause any serious sampling damages, and its assessment accuracy is at a high level. However, in applying the SPC test to the residual creep life assessment of the boiler in service, there are some issues to be studied. In order to apply SPC test to the residual creep life assessment of the 2.25Cr-1Mo steel boiler pipe, the relationship between uniaxial creep stress and the SPC test load has been studied. The virgin material, pre-crept, weldment and service aged samples of 2.25Cr-1Mo steel were tested. It was confirmed that the relationship between uniaxial creep stress and the SPC test load at the same rupture time can be described as a single straight line independent of test conditions and materials. Therefore a life assessment is possible by using SPC test in place of uniaxial creep tests. The creep life assessment using SPC was applied to actual thermal power plant components which are in service.
International Nuclear Information System (INIS)
Ohmi, Masao; Saito, Junichi; Ooka, Norikazu; Jitsukawa, Shiro; Hishinuma, Akimichi; Umino, Akira.
1997-01-01
An accelerator-driven deuterium-lithium (d-Li) stripping reaction-type neutron source, such as the International Fusion Materials Irradiation Facility (IFMIF) planned by the International Energy Agency is recognized as one of the most promising facility to obtain test environments of high-energy neutrons for fusion reactor materials development. The limitation on the available irradiation volume of the irradiation facility requires the development of the small specimen test techniques (SSTT). Application of SSTT to evaluate the degradation of various components in the light water reactor for the life extension is expected to be also quite beneficial. A remote-controlled testing machine for the Small Punch (SP) and miniaturized tensile tests was developed at the hot laboratory of the Japan Materials Testing Reactor (JMTR). The machine is designed for testing at temperatures ranging between 93 and 1,123 K to evaluate the temperature dependence of the strength of materials including the embrittlement at low temperatures and the softening at elevated temperatures. The tests are performed in a vacuum or in an inert gas environment. The machine has been installed in a hot cell and is being used for the round robin test program of the SP test method. The round robin test program is planned to identify the capability of the test method and to establish a standard test procedure. The configuration and the specifications of the test machine are introduced and the results of the SP tests are also shown. (author)
Failure criterion of concrete type material and punching failure analysis of thick mortar plate
International Nuclear Information System (INIS)
Ohno, T.; Kuroiwa, M.; Irobe, M.
1979-01-01
In this paper falure surface of concrete type material is proposed and its validity to structural analysis is examined. The study is an introductory part of evaluation for ultimate strength of reinforced and prestressed concrete structures in reactor technology. The failure surface is expressed in a linear form in terms of octahedral normal and shear stresses. Coefficient of the latter stress is given by a trigonometric series in threefold angle of similarity. Hence, its meridians are multilinear and traces of its deviatoric sections are smooth curves having periodicity of 2π/3 around space diagonal in principal stress space. The mathematical expression of the surface has an arbitraty number of parameters so that material test results are well reflected. To confirm the effectiveness of proposed failure criterion, experiment and numerical analysis by the finite element method on punching failure of thick mortar plate in axial symmetry are compared. In the numerical procedure yield surface of the material is assumed to exist mainly in compression region, since a brittle cleavage or elastic fracture occurs in the concrete type material under stress state with tension, while a ductile or plastic fracture occurs under compressive stress state. (orig.)
Directory of Open Access Journals (Sweden)
Lancaster Robert
2018-01-01
Full Text Available Additive layer manufacturing (ALM processes are becoming increasingly prevalent in the aerospace industry as design engineers look to profit from the numerous advantages that these advanced techniques can offer. However, given the safety critical nature and arduous operating conditions to which these components will be exposed to whilst in service, it is essential that the mechanical properties of such structures are fully understood. Transient microstructures are a typical characteristic of ALM components and resulting from the thermal cycles that occur during the build operation. Those microstructures make any mechanical assessment an involved procedure when assessing the process variables for any given parameter set. A useful mechanical test technique is small-scale testing, in particular, the small punch (SP test. SP testing is capable of localised sampling of a larger scale component and presents an attractive option to mechanically assess complex parts with representative geometries, that would not be possible using more conventional uniaxial test approaches. This paper will present the recent development of a small-scale testing methodology capable of inducing fatigue damage and a series of novel tests performed on different variants of Ti-6Al-4V.
WHAT IS THE BEST RADIOGRAPHIC VIEW FOR "DIE PUNCH" DISTAL RADIUS FRACTURES? A CADAVER MODEL STUDY.
Falcochio, Diego Figueira; Crepaldi, Bruno Eiras; Trindade, Christiano Augusto; da Costa, Antonio Carlos; Chakkour, Ivan
2012-01-01
the aim of this study is try to show the best view for distal radius fractures so called die-punch fractures. There has been used a human cadaver radius bone from the Salvador Arena Tissue Bank. This bone was cleaned up after removing the soft tissues and osteotomies created displaced lunate fossa fractures of 0, 1, 2, 3 and 5 mm. We have fixed this fragment with adhesive tape. Then the joint deviation were significantly increased with step-offs of 1 mm. Radiographs were then taken into 5 different positions: postero-anterior view, lateral view, oblique views and tangencial view for each of the deviations. The resulting lunate fossa depression in each X-ray film was analyzed by the AutoCAD 2010® software. The tangencial view was the best one to see the 1mm and 3mm bone degrees and the second one view to see the 2mm and 5 mm degrees. The pronated oblique view was the best to see the 2mm degrees and the oblique supinated view wasn't able to see the degrees between 1 and 2mm. The tangencial view was the best one to see the 1mm and 3mm bone degrees and the second one view to see the 2mm and 5 mm degrees.
User-Authentication on Wearable Devices Based on Punch Gesture Biometrics
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Liang Guan-Cheng
2017-01-01
Full Text Available Due to commoditization and convenience, wearable technology are interwoven with our daily life. However, privacy sensitive data stored on those devices such as personal email, message can be easily stolen. Most devices require a PIN input to unlock. However, this mechanism is vulnerable to shoulder surfing attack. Thus many novel authentication approaches have been proposed to solve this problem. And biometric-based methods have been adopted by many researchers because of the efficiency and excellent performance. In this paper, we propose a new biometric-based authentication system. We focus on how the user performs a straight punch gesture subconsciously. By analysis the acceleration data from the smartwatch when user performing the gesture, we are able to profile the user. And we authenticate the user according to the biometrics of this action. This mechanism is light-weighted and do not require user to remember any secret code. We develop an authentication system on Samsung Gear Fit 2 and conducted a real-world experiment on 20 volunteers. And we collected 13000 gesture samples to evaluate our system. Results show that our system can achieve a classification accuracy of at least 95.45%. In attacking scenario, our system can achieve an equal error rate lower than 4%. The maximum number of samples required by a well-trained classifier is 25.
Ganesh Kumar, J.; Laha, K.; Ganesan, V.; Prasad Reddy, G. V.
2018-04-01
The small punch creep (SPC) behavior of 316LN stainless steel (SS) containing 0.07, 0.11 and 0.14 wt.% nitrogen has been investigated at 923 K. The transient and tertiary SPC deformation of 316LN SS with various nitrogen contents have been analyzed according to the equation proposed for SPC deflection, δ = δ0 + δT (1 - e^{ - κ t} ) + \\dot{δ }s t + δ3 e^[ φ( t - tr ) ]. The relationships among the rate of exhaustion of transient creep (κ), steady-state deflection rate (\\dot{δ }s ) and the rate of acceleration of tertiary creep (φ) revealed the interrelationships among the three stages of SPC curve. The first-order reaction rate theory was found to be applicable to SPC deformation throughout the transient as well as tertiary region, in all the investigated steels. The initial and final creep deflection rates were decreased, whereas time to attain steady-state deflection rate increased with the increase in nitrogen content. By increasing the nitrogen content in 316LN SS from 0.07 to 0.14 wt.%, each stage of SPC was prolonged, and consequently, the values of κ, \\dot{δ }s and φ were lowered. Using the above parameters, the master curves for both transient and tertiary SPC deflections were constructed for 316LN SS containing different nitrogen contents.
Kurtz, S M; Siskey, R; Reitman, M
2010-05-01
The objectives of this study were three-fold: (1) to determine the applicability of the small punch test to characterize Bionate 80A polycarbonate urethane (PCU) acetabular implants; (2) to evaluate the susceptibility of PCU acetabular implants to exhibit degradation of mechanical behavior following gamma irradiation in air and accelerated aging; and (3) to compare the oxidation of gamma-air sterilized PCU following accelerated aging and 5 years of natural shelf aging. In addition to attenuated total reflectance-Fourier transform infrared spectroscopy, we also adapted a miniature specimen mechanical test, the small punch test, for the deformable PCU cups. Accelerated aging was performed using ASTM F2003, a standard test that represents a severe oxidative challenge. The results of this study suggest that the small punch test is sufficiently sensitive and reproducible to discriminate slight differences in the large-deformation mechanical behavior of Bionate 80A following accelerated aging. The gamma-air sterilized PCU had a reduction of 9% in ultimate load after aging. Five years of shelf aging had little effect on the mechanical properties of the PCU. Overall, our findings suggest that the Bionate 80A material has greater oxidative stability than ultra-high molecular weight polyethylene following gamma irradiation in air and exposure to a severe oxidative challenge. (c) 2010 Wiley Periodicals, Inc.
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Ahmad Sedaghat
2017-01-01
Full Text Available The PBL unit of fluid and electrical drive systems is taught in final semester of undergraduates in mechanical engineering department of the Australian College of Kuwait (ACK. The recent project on an automated punching machine is discovered more appealing to both students and instructors in triggering new ideas and satisfaction end results. In this case study, the way this PBL unit is coordinated and facilitated is explained. Two examples of student works are presented. The aim is to expose the students to real world engineering problems but in a satisfying manner. Similar to real life problems for engineers, restrictions are applied for the students on costs, availability of ACK facilities, and application of automation tools. Students are directly engaged by using technical standards on punching heads and dies, standard tensile testing of plates, and so on. Arduino microprocessor programming, an open-source hardware and software electronic platform, and electro-pneumatic devices are adopted for developing the automated punching machine. The goal of the PBL course is to acquaint students learning based on the concepts of team working, engineering design, professional manufacturing, and sequential testing of the end product. It is found that students achieved their best and developed new skills in this PBL unit as reflected in their portfolios.
Demonstration of the self-magnetic-pinch diode as an X-ray source for flash core-punch radiography
International Nuclear Information System (INIS)
Cordova, Steve Ray; Rovang, Dean Curtis; Portillo, Salvador; Oliver, Bryan Velten; Bruner, Nichelle Lee; Ziska, Derek Raymond
2007-01-01
Minimization of the radiographic spot size and maximization of the radiation dose is a continuing long-range goal for development of electron beam driven X-ray radiography sources. In collaboration with members of the Atomic Weapons Establishment(AWE), Aldermaston UK, the Advanced Radiographic Technologies Dept. 1645 is conducting research on the development of X-ray sources for flash core-punch radiography. The Hydrodynamics Dept. at AWE has defined a near term radiographic source requirement for scaled core-punch experiments to be 250 rads(at)m with a 2.75 mm source spot-size. As part of this collaborative effort, Dept. 1645 is investigating the potential of the Self-Magnetic-Pinched (SMP) diode as a source for core-punch radiography. Recent experiments conducted on the RITS-6 accelerator [1,2] demonstrated the potential of the SMP diode by meeting and exceeding the near term radiographic requirements established by AWE. During the demonstration experiments, RITS-6 was configured with a low-impedance (40 (Omega)) Magnetically Insulated Transmission Line (MITL), which provided a 75-ns, 180-kA, 7.5-MeV forward going electrical pulse to the diode. The use of a low-impedance MITL enabled greater power coupling to the SMP diode and thus allowed for increased radiation output. In addition to reconfiguring the driver (accelerator), geometric changes to the diode were also performed which allowed for an increase in dose production without sacrificing the time integrated spot characteristics. The combination of changes to both the pulsed power driver and the diode significantly increased the source x-ray intensity
Deng, Qihuang; Fan, Yuchi; Wang, Lianjun; Xiong, Zhi; Wang, Hongzhi; Li, Yaogang; Zhang, Qinghong; Kawasaki, Akira; Jiang, Wan
2012-01-01
Pb(Zr,Ti)O3 (PZT) ceramics were prepared by the conventional mixed oxide method, and the strength of the resultant PZT ceramics was evaluated using modified small punch (MSP) tests. Load-displacement curve test results showed that the crack-initiation and fracture strengths of PZT ceramics decreased after polarization. The effect of the polarization accelerated the fatigue properties of PZT ceramics. Scanning electron microscopy (SEM) results showed that microcracks were formed before the maximum load in the MSP test, and the first load drop corresponded to crack initiation.
Energy Technology Data Exchange (ETDEWEB)
Chin, Eric Brian [Sandia National Lab. (SNL-CA), Livermore, CA (United States); English, Shawn Allen [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Briggs, Timothy [Sandia National Lab. (SNL-CA), Livermore, CA (United States)
2015-09-01
V arious phenomenological delamination initiation criteria are analyzed in quasi - static punch - shear tests conducted on six different geometries. These six geometries are modeled and analyzed using elastic, large - deformation finite element analysis. Analysis output is post - processed to assess different delamination initiation criteria, and their applicability to each of the geometries. These criteria are compared to test results to assess whether or not they are appropriate based on what occurred in testing. Further, examinations of CT scans and ultrasonic images o f test specimens are conducted in the appendix to determine the sequence of failure in each test geometry.
Laker-Oketta, Miriam O; Wenger, Megan; Semeere, Aggrey; Castelnuovo, Barbara; Kambugu, Andrew; Lukande, Robert; Asirwa, F Chite; Busakhala, Naftali; Buziba, Nathan; Diero, Lameck; Wools-Kaloustian, Kara; Strother, Robert Matthew; Bwana, Mwebesa; Muyindike, Winnie; Amerson, Erin; Mbidde, Edward; Maurer, Toby; Martin, Jeffrey
2015-01-01
Fueled by HIV, sub-Saharan Africa has the highest incidence of Kaposi's sarcoma (KS) in the world. Despite this, KS diagnosis in the region is based mostly on clinical grounds. Where biopsy is available, it has traditionally been excisional and performed by surgeons, resulting in multiple appointments, follow-up visits for suture removal, and substantial costs. We hypothesized that a simpler approach - skin punch biopsy - would make histologic diagnosis more accessible. To address this, we provided training and equipment for skin punch biopsy of suspected KS to three HIV clinics in East Africa. The procedure consisted of local anesthesia followed by a disposable cylindrical punch blade to obtain specimens. Hemostasis is facilitated by Gelfoam®. Patients removed the dressing after 4 days. From 2007 to 2013, 2,799 biopsies were performed. Although originally targeted to be used by physicians, biopsies were performed predominantly by nurses (62%), followed by physicians (15%), clinical officers (12%) and technicians (11%). There were no reports of recurrent bleeding or infection. After minimal training and provision of inexpensive equipment (USD 3.06 per biopsy), HIV clinics in East Africa can integrate same-day skin punch biopsy for suspected KS. Task shifting from physician to non-physician greatly increases access. Skin punch biopsy should be part of any HIV clinic's essential procedures. This example of task shifting may also be applicable to the diagnosis of other cancers (e.g., breast) in resource-limited settings.
Ogden, Samantha J; Horton, Jeffrey K; Stubbs, Simon L; Tatnell, Peter J
2015-01-01
The 1.2 mm Electric Coring Tool (e-Core™) was developed to increase the throughput of FTA(™) sample collection cards used during forensic workflows and is similar to a 1.2 mm Harris manual micro-punch for sampling dried blood spots. Direct short tandem repeat (STR) DNA profiling was used to compare samples taken by the e-Core tool with those taken by the manual micro-punch. The performance of the e-Core device was evaluated using a commercially available PowerPlex™ 18D STR System. In addition, an analysis was performed that investigated the potential carryover of DNA via the e-Core punch from one FTA disc to another. This contamination study was carried out using Applied Biosystems AmpflSTR™ Identifiler™ Direct PCR Amplification kits. The e-Core instrument does not contaminate FTA discs when a cleaning punch is used following excision of discs containing samples and generates STR profiles that are comparable to those generated by the manual micro-punch. © 2014 American Academy of Forensic Sciences.
MODERN METHODS OF DESIGN AND ARRANGEMENT OF RAMMING PILES IN PUNCHED HOLES
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ZOTSENKO N. L.
2015-10-01
Full Text Available Problem statement. Ramming piles in punched holes (RPPH differ of high degree of use of supporting capacity of base because of forming in it a compacted zone at the expense of displacement of soil in the volume rammer and compacted material of expansion. The method of their construction almost exclude excavation and formwork, reducing the consumption of concrete, metal, accelerates zero cycle compared to the foundations raised and excavation and immersion into the soil of precast elements. The expansion of the normative base, their design and construction should be for further implementation of of natural objects. The correctness of the geomechanical model of plane and spatial version of finite element method (FEM should be proved for the calculation of cooperative work of RPPH as part of grillages with base. The most effective kinds of equipment and technological schemes of construction of RPPH should be noticed. Conclusions. The paper presents the main regulations on the design and the arrangement RPPH, corresponding of construction norms of Ukraine. The results of experimental and theoretical studies conducted by the authors for over thirty years, and the experience of the use of these piles on the objects of civil engineering, industrial and agricultural construction made their base. The use of the elastoplastic model with the criterion of Mohr-Coulomb strength for designing of the system "grillage -RPPH- soil" was substantiated. The designing in plane and spatial problems of FEM is proved that in the distance between the axes of adjacent piles up to five diameters is a correct choice of a flat version and simplifying of calculating scheme to the conventional strip foundation. An improved. The method of calculating of RPPH as part of grillages ribbon, where as the width of the foundation was taken a diameter of the broadening of the pile, and the depth of its inception corresponds to the bottom of it. The supporting layer of base under the
Highly sensitive photodetector based on ge double-barrier punch-through structure
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Abdulkhaev O. A.
2015-08-01
Full Text Available In recent years, transmission and reception systems of optical signals are widely used. Receiving the optical signal in such systems is carried by photoreceiving modules based on a photodetector, which defines the quality of the received signal, the range and speed of the entire system. However, hitherto used p–i–n- and avalanche photodiodes do not fully meet the growing demands. The present work is devoted to investigate the photovoltaic characteristics of semiconductor thin base transistor structure based on germanium, which is superior the silicon counterparts by speed and gain. Investigated p+–n–p-structures were obtained by diffusion of antimony onto the substrate of p-type germanium to a depth of 1 micron and alloying of indium to the part of its surface which creates diffusion layer of ?+-type and with thickness of 0,5 microns. Experiments have shown that the reverse biasing of a single p+-n-emitter-base junction leads to a smooth increase in reverse current, at the same time when it is connected in series to forward biased collector p-n-junction there is a sharp increase in the current by voltage, giving properties of voltage surge suppressor. This behavior of the current-voltage characteristics can be explained by the punch-through effect when the space charge regions of the emitter junction and the space charge region of collector junction touch each other and the conditions are realized for double carrier injection into a fully depleted region of the transistor. At the same time giving small fixed voltages 0,1—0,15 V to the collector-base junction the output static characteristics can be received with an operating voltage of 3—3,5 V. A characteristic feature of the investigated transistor is that when the base region under illumination by integrated light intensity (50 and 3000 lux light current appears, whose magnitude with the increase of operating voltage (up to 1.7 V increases nonlinearly, resulting in increased
Ito, Manabu; Aoki, Shigeru; Uchiyama, Jumpei; Yamato, Keisuke
2018-04-20
Sticking is a common observation in the scale-up stage on the punch tip using a commercial tableting machine. The difference in the total compression time between a laboratory and a commercial tableting machine is considered one of the main root causes of scale up issues in the tableting processes. The proposed Size Adjusted for Scale-up (SAS) punch can be used to adjust the consolidation and dwell times for commercial tableting machine. As a result, the sticking phenomenon is able to be replicated at the pilot scale stage. As reported in this paper, the quantification of sticking was measured using a 3D laser scanning microscope to check the tablet surface. It was shown that the sticking area decreased with the addition of magnesium stearate in the formulation, but the sticking depth was not affected by the additional amount of magnesium stearate. It is proposed that use of a 3D laser scanning microscope can be applied to evaluate sticking as a process analytical technology (PAT) tool and so sticking can be monitored continuously without stopping the machine. Copyright © 2018. Published by Elsevier Inc.
Zhang, Ri-Hui; Kang, Zhi-Xin
2011-05-01
To study training effect of upper limbs and lumbar muscles in the proceed of air striking of straight punch by analyzing boxing athletes' changes of electromyogram (EMG). We measured EMG of ten women boxing athletes' upper arm biceps (contractor muscle), upper arm triceps (antagonistic muscle), forearm flexor muscle (contractor muscle), forearm extensor muscle (antagonistic muscle), and lumbar muscles by ME6000 (Mega Electronics Ltd.). The stipulated exercise was to do air striking of straight punch with loads of 2.5 kg of dumbbell in the hand until exhausted. In the proceed of exercise-induce exhausted, the descend magnitude and speed of median frequency (MF) in upper limb antagonistic muscle exceeded to contracting muscle, moreover, the work percentage showed that contractor have done a larger percentage of work than antagonistic muscle. Compared with world champion's EMG, the majority of ordinary athletes' lumbar muscles MF revealed non-drop tendency, and the work percentage showed that lumbar muscles had a very little percentage of work. After comparing the EMG test index in upper limb and lumbar muscle of average boxing athletes with that of the world champion, we find the testees lack of the training of upper limb antagonistic muscle and lumbar muscle, and more trainings aimed at these muscles need to be taken.
Energy Technology Data Exchange (ETDEWEB)
Isselin, J
2003-03-15
The aging of the electric production park implies an increasing need of knowledge concerning the evolution of the mechanical properties of its components. With regard to this problem, the availability in material is more and more small. This work proposes to characterize these properties through a mechanical test called Punch test. The main characteristic of this test is to use very small volume samples. The development of this test has been carried out by the study of a 15 MDV 4-05 steel coming from a steam drum of a thermal power plant after 145000 hours of service. At first, we have measured the influence of the parameters of this test. Then, the study has dealt more particularly on the transition temperature of the material. With the finite element simulation method, the strain hardening coefficient of the material has been determined. (O.M.)
DEFF Research Database (Denmark)
Stangegaard, Michael; Olsen, Addie Nina; Frøslev, Tobias G.
2009-01-01
We have implemented and validated automated methods for washing FTA Card punches containing buccal samples and subsequent PCR setup using a Sias Xantus automated liquid handler. The automated methods were controlled by worklists generated by our LabWare Laboratory Information Management System...
Giddings, V L; Kurtz, S M; Jewett, C W; Foulds, J R; Edidin, A A
2001-07-01
Polymethylmethacrylate (PMMA) bone cement is used in total joint replacements to anchor implants to the underlying bone. Establishing and maintaining the integrity of bone cement is thus of critical importance to the long-term outcome of joint replacement surgery. The goal of the present study was to evaluate the suitability of a novel testing technique, the small punch or miniaturized disk bend test, to characterize the elastic modulus and fracture behavior of PMMA. We investigated the hypothesis that the crack initiation behavior of PMMA during the small punch test was sensitive to the test temperature. Miniature disk-shaped specimens, 0.5 mm thick and 6.4 mm in diameter, were prepared from PMMA and Simplex-P bone cement according to manufacturers' instructions. Testing was conducted at ambient and body temperatures, and the effect of test temperature on the elastic modulus and fracture behavior was statistically evaluated using analysis of variance. For both PMMA materials, the test temperature had a significant effect on elastic modulus and crack initiation behavior. At body temperature, the specimens exhibited "ductile" crack initiation, whereas at room temperature "brittle" crack initiation was observed. The small punch test was found to be a sensitive and repeatable test method for evaluating the mechanical behavior of PMMA. In light of the results of this study, future small punch testing should be conducted at body temperature.
Green, Troy N.
2017-06-12
Membrane punch autopsy (MPA) is a procedure for quantitative foulant analysis of hollow fine fiber (HFF) permeators. In the past, quantitative autopsies of membranes were restricted to spiral wound. This procedure was developed at SWCC laboratories and tested on permeators of two commercial Red Sea reverse osmosis plants. For membrane autopsies, stainless steel hollow bore picks were penetrated to membrane cores and fibers extracted for foulant analysis. Quantitative analysis of extracted materials contained inorganic and organic foulants including bacteria. Fourier transform infrared spectroscopy analysis confirmed the presence of organic fouling functional groups and scanning electron microscopy with energy dispersive X-ray spectroscopy in the presence of diatoms and silica most likely not from particulate sand. API analysis revealed the presence of Shewanella and two Vibrio microbial species confirmed by 16S rDNA sequence library. It was observed that fouling content of HFF cellulose triacetate (CTA) membranes were more than 800 times than polyamide spiral wound membranes.
Energy Technology Data Exchange (ETDEWEB)
Sperling, F; Hennecke, A
1981-10-29
The invention describes a machine, which places the cast parts from a two-part, vertical casting mould onto a transport unit using a lifting device, without any danger of deformation of the not yet hardened grid plates by mechanical loads. The lifting device and rider of the transport unit have guides, in which the plate rests with its grid wings. The transport unit consists of endless chains of variable distance and is also used for cooling, by taking air, for example, as cooling medium through a suitably shaped metal jacket. At the end of the cooling area, the castings are gripped at the bottom by axially controlled pegs pointing towards the inside, and are brought into the horizontal level by a movement of the chains. They are laid on a plate fitted between the chain wheels and are taken by side cams to the punch, from which they are discharged via a further pair of cams on to a belt.
Directory of Open Access Journals (Sweden)
Nassim Kernou
2018-01-01
Full Text Available A rational three-dimensional nonlinear finite element model (NLFEAS is used for evaluating the behavior of high strength concrete slabs under monotonic transverse load. The non-linear equations of equilibrium have been solved using the incremental-iterative technique based on the modified Newton-Raphson method. The convergence of the solution was controlled by a load convergence criterion. The validity of the theoretical formulations and the program used was verified, through comparison with results obtained using ANSYS program and with available experimental test results. A parametric study was conducted to investigate the effect of different parameters on the behavior of slabs which was evaluated in terms of loaddeflection characteristics, concrete and steel stresses and strains, and failure mechanisms. Also, punching shear resistance of slabs was numerically evaluated and compared with the prediction specified by some design codes.
DEFF Research Database (Denmark)
Ellegaard, Peter
2007-01-01
The span of roof trusses with punched metal plate fasteners (nail plates) makes it often necessary to use splice joints in the top and bottom chords. In the finite element models used for design of the trusses these splice joints are normally assumed to be either rotationally stiff or pinned....... Timber-to-timber contact and non-linear elastic behaviour are included in the model. Results from tests with joints under fourpoint bending are compared with predictions given by TrussLab, and a good agreement is found. Splice joints in trusses with nail plates may be assumed to be rotationally stiff...... if their deformation has no significant effect upon the distribution of member forces according to Eurocode 5. Two simple guidelines for the design and location of splice joints are given in Eurocode 5 for treating the splice joints as rotationally stiff. The reasonability of these guidelines and the influence...
2013-01-01
Introduction Current therapies for articular cartilage defects fail to achieve qualitatively sufficient tissue regeneration, possibly because of a mismatch between the speed of cartilage rebuilding and the resorption of degradable implant polymers. The present study focused on the self-healing capacity of resident cartilage cells in conjunction with cell-free and biocompatible (but non-resorbable) bacterial nanocellulose (BNC). This was tested in a novel in vitro bovine cartilage punch model. Methods Standardized bovine cartilage discs with a central defect filled with BNC were cultured for up to eight weeks with/without stimulation with transforming growth factor-β1 (TGF-β1. Cartilage formation and integrity were analyzed by histology, immunohistochemistry and electron microscopy. Content, release and neosynthesis of the matrix molecules proteoglycan/aggrecan, collagen II and collagen I were also quantified. Finally, gene expression of these molecules was profiled in resident chondrocytes and chondrocytes migrated onto the cartilage surface or the implant material. Results Non-stimulated and especially TGF-β1-stimulated cartilage discs displayed a preserved structural and functional integrity of the chondrocytes and surrounding matrix, remained vital in long-term culture (eight weeks) without signs of degeneration and showed substantial synthesis of cartilage-specific molecules at the protein and mRNA level. Whereas mobilization of chondrocytes from the matrix onto the surface of cartilage and implant was pivotal for successful seeding of cell-free BNC, chondrocytes did not immigrate into the central BNC area, possibly due to the relatively small diameter of its pores (2 to 5 μm). Chondrocytes on the BNC surface showed signs of successful redifferentiation over time, including increase of aggrecan/collagen type II mRNA, decrease of collagen type I mRNA and initial deposition of proteoglycan and collagen type II in long-term high-density pellet cultures
Bruchhausen, Matthias; Lapetite, Jean-Marc; Ripplinger, Stefan; Austin, Tim
2016-12-01
Raw data from small punch tensile/fracture tests at two displacement rates in the temperature range from -196 °C to room temperature on Grade 91 ferritic/martensitic steel are presented. A number of specimens were analyzed after testing by means of X-ray computed tomography (CT). Based on the CT volume data detailed 3D surface maps of the specimens were established. All data are open access and available from Online Data Information Network (ODIN)https://odin.jrc.ec.europa.eu. The data presented in the current work has been analyzed in the research article "On the determination of the ductile to brittle transition temperature from small punch tests on Grade 91 ferritic-martensitic steel" (M. Bruchhausen, S. Holmström, J.-M. Lapetite, S. Ripplinger, 2015) [1].
Wu, Li-Wei; Lin, Wen-Jie; Hsu, Yu-Feng
2018-01-01
Abstract The Tailed Punch, Dodona eugenes, is widely distributed in East Asia with seven subspecies currently recognized. However, two of them, namely ssp. formosana and ssp. esakii found in Taiwan, are hard to distinguish from each other due to ambiguous diagnostic characters. In this study, their taxonomic status is clarified by comparing genitalia characters and phylogenetic relationships based on mitochondrial sequences, COI and COII (total 2211 bps). Our results show that there is no reliable feature to separate these two subspecies. Surprisingly we found that Dodona in Taiwan is more closely related to the Orange Punch, D. egeon, than to other subspecies of D. eugenes. Therefore, the following nomenclatural changes are proposed: Dodona eugenes formosana is revised to specific status as Dodona formosana Matsumura, 1919, stat. rev, and ssp. esakii is sunk to a junior synonym of Dodona formosana syn. n. PMID:29674868
Directory of Open Access Journals (Sweden)
Li-Wei Wu
2018-02-01
Full Text Available The Tailed Punch, Dodona eugenes, is widely distributed in East Asia with seven subspecies currently recognized. However, two of them, namely ssp. formosana and ssp. esakii found in Taiwan, are hard to distinguish from each other due to ambiguous diagnostic characters. In this study, their taxonomic status is clarified by comparing genitalia characters and phylogenetic relationships based on mitochondrial sequences, COI and COII (total 2211 bps. Our results show that there is no reliable feature to separate these two subspecies. Surprisingly we found that Dodona in Taiwan is more closely related to the Orange Punch, D. egeon, than to other subspecies of D. eugenes. Therefore, the following nomenclatural changes are proposed: Dodona eugenes formosana is revised to specific status as Dodona formosana Matsumura, 1919, stat. rev, and ssp. esakii is sunk to a junior synonym of Dodona formosana syn. n.
Faghihi, Gita; Nouraei, Saeid; Asilian, Ali; Keyvan, Shima; Abtahi-Naeini, Bahareh; Rakhshanpour, Mehrdad; Nilforoushzadeh, Mohammad Ali; Hosseini, Sayed Mohsen
2015-01-01
Background: A number of treatments for reducing the appearance of acne scars are available, but general guidelines for optimizing acne scar treatment do not exist. The aim of this study was to compare the clinical effectiveness and side effects of fractional carbon dioxide (CO2) laser resurfacing combined with punch elevation with fractional CO2 laser resurfacing alone in the treatment of atrophic acne scars. Materials and Methods: Forty-two Iranian subjects (age range 18–55) with Fitzpatrick skin types III to IV and moderate to severe atrophic acne scars on both cheeks received randomized split-face treatments: One side received fractional CO2 laser treatment and the other received one session of punch elevation combined with two sessions of laser fractional CO2 laser treatment, separated by an interval of 1 month. Two dermatologists independently evaluated improvement in acne scars 4 and 16 weeks after the last treatment. Side effects were also recorded after each treatment. Results: The mean ± SD age of patients was 23.4 ± 2.6 years. Clinical improvement of facial acne scarring was assessed by two dermatologists blinded to treatment conditions. No significant difference in evaluation was observed 1 month after treatment (P = 0.56). Their evaluation found that fractional CO2 laser treatment combined with punch elevation had greater efficacy than that with fractional CO2 laser treatment alone, assessed 4 months after treatment (P = 0.02). Among all side effects, coagulated crust formation and pruritus at day 3 after fractional CO2 laser treatment was significant on both treatment sides (P < 0.05). Conclusion: Concurrent use of fractional laser skin resurfacing with punch elevation offers a safe and effective approach for the treatment of acne scarring. PMID:26538695
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Gita Faghihi
2015-01-01
Full Text Available Background: A number of treatments for reducing the appearance of acne scars are available, but general guidelines for optimizing acne scar treatment do not exist. The aim of this study was to compare the clinical effectiveness and side effects of fractional carbon dioxide (CO 2 laser resurfacing combined with punch elevation with fractional CO 2 laser resurfacing alone in the treatment of atrophic acne scars. Materials and Methods: Forty-two Iranian subjects (age range 18-55 with Fitzpatrick skin types III to IV and moderate to severe atrophic acne scars on both cheeks received randomized split-face treatments: One side received fractional CO 2 laser treatment and the other received one session of punch elevation combined with two sessions of laser fractional CO 2 laser treatment, separated by an interval of 1 month. Two dermatologists independently evaluated improvement in acne scars 4 and 16 weeks after the last treatment. Side effects were also recorded after each treatment. Results: The mean ± SD age of patients was 23.4 ± 2.6 years. Clinical improvement of facial acne scarring was assessed by two dermatologists blinded to treatment conditions. No significant difference in evaluation was observed 1 month after treatment (P = 0.56. Their evaluation found that fractional CO 2 laser treatment combined with punch elevation had greater efficacy than that with fractional CO 2 laser treatment alone, assessed 4 months after treatment (P = 0.02. Among all side effects, coagulated crust formation and pruritus at day 3 after fractional CO 2 laser treatment was significant on both treatment sides (P < 0.05. Conclusion: Concurrent use of fractional laser skin resurfacing with punch elevation offers a safe and effective approach for the treatment of acne scarring.
Czech Academy of Sciences Publication Activity Database
Besterci, M.; Dobeš, Ferdinand; Ballóková, B.; Sülleiová, K.; Kvačkaj, T.
2011-01-01
Roč. 30, č. 3 (2011), s. 205-210 ISSN 0334-6455 R&D Projects: GA AV ČR 1QS200410502; GA AV ČR IAA200410801 Grant - others:Vega(SK) 2/0025/11 Institutional research plan: CEZ:AV0Z20410507 Keywords : Equal channel angular pressing * small-punch creep * fracture * metal-matrix composites Subject RIV: JI - Composite Materials Impact factor: 0.242, year: 2011
International Nuclear Information System (INIS)
Nho, Seung Hwan; Ong, Jang Woo; Yu, Hyo Sun; Chung, Se Hi
1996-01-01
The purpose of this study is to investigate the usefulness of small punch(SP) test using miniaturized specimens as a method for fracture strength evaluation of CANDU pressure tube embrittled by hydrogen. According to the test results, the fracture strength evaluation as a function of hydrogen concentration at -196 .deg. C was much better than that at room temperature, as the difference of SP fracture energy(Esp) with hydrogen concentration was more significant at -196 .deg. C than at room temperature for the hydrogen concentration up to 300ppm-H. It was also observed that the peak of average AE energy, the cumulative average AE energy and the cumulative average AE energy per equivalent fracture, strain increased with the increase of hydrogen concentration. From the results of load-displacement behaviors, Esp behaviors, macro- and micro-SEM fractographs and AE test it has been concluded that the SP test method using miniaturized specimen(10mmx10mmx0.5mm) will be a useful test method to evaluate the fracture strength for CANDU pressure tube embrittled by hydrogen
Masai, Kyohei; Sasada, Shinji; Izumo, Takehiro; Taniyama, Tomoko; Nakamura, Yukiko; Chavez, Christine; Sakurai, Hiroyuki; Tsuta, Koji; Tsuchida, Takaaki
2013-10-01
Desmoplastic malignant mesothelioma (DMM) is a rare subtype of malignant pleural mesothelioma (MPM) and is often difficult to distinguish from pleural fibrosis and reactive mesothelial hyperplasia, especially if the biopsy samples are small. We performed full-thickness pleural biopsy on a lesion suspected to be DMM using an insulated-tip diathermic knife-2 (IT knife-2) during flex-rigid pleuroscopy. IT knife-2 is a novel electrosurgical device for endoscopic submucosal dissection in the early gastrointestinal cancer. It consists of a needle knife with 3 short blades at the distal end attached to an insulated ceramic tip. A 54-year-old man presenting with chest wall mass and thickened pleura, in whom a computed tomography-guided percutaneous needle aspiration had remained negative, underwent flex-rigid pleuroscopy for definitive diagnosis. While applying electric current, we used the IT knife-2 to incise the pleura in a circular shape just above the endothoracic fascia. The incised pleura was removed by forceps and examined pathologically. The microscopic examination was compatible with DMM. We discovered that pleuroscopic punch biopsy using IT knife-2 can diagnose DMM. Use of IT knife-2 during flex-rigid pleuroscopy can obtain sufficient samples from densely thickened pleura, which is difficult to diagnose with small biopsies.
Directory of Open Access Journals (Sweden)
Beltrame Francesco
2010-11-01
Full Text Available Abstract Background Tissue MicroArray technology aims to perform immunohistochemical staining on hundreds of different tissue samples simultaneously. It allows faster analysis, considerably reducing costs incurred in staining. A time consuming phase of the methodology is the selection of tissue areas within paraffin blocks: no utilities have been developed for the identification of areas to be punched from the donor block and assembled in the recipient block. Results The presented work supports, in the specific case of a primary subtype of breast cancer (tubular breast cancer, the semi-automatic discrimination and localization between normal and pathological regions within the tissues. The diagnosis is performed by analysing specific morphological features of the sample such as the absence of a double layer of cells around the lumen and the decay of a regular glands-and-lobules structure. These features are analysed using an algorithm which performs the extraction of morphological parameters from images and compares them to experimentally validated threshold values. Results are satisfactory since in most of the cases the automatic diagnosis matches the response of the pathologists. In particular, on a total of 1296 sub-images showing normal and pathological areas of breast specimens, algorithm accuracy, sensitivity and specificity are respectively 89%, 84% and 94%. Conclusions The proposed work is a first attempt to demonstrate that automation in the Tissue MicroArray field is feasible and it can represent an important tool for scientists to cope with this high-throughput technique.
Mitsui, S.; Unno, Y.; Ikegami, Y.; Takubo, Y.; Terada, S.; Hara, K.; Takahashi, Y.; Jinnouchi, O.; Nagai, R.; Kishida, T.; Yorita, K.; Hanagaki, K.; Takashima, R.; Kamada, S.; Yamamura, K.
2013-01-01
Planar geometry silicon pixel and strip sensors for the high luminosity upgrade of the LHC (HL-LHC) require a high bias voltage of 1000 V in order to withstand a radiation damage caused by particle fluences of 1×1016 1 MeV neq/cm2 and 1×1015 1 MeV neq/cm2 for pixel and strip detectors, respectively. In order to minimize the inactive edge space that can withstand a bias voltage of 1000 V, edge regions susceptible to microdischarge (MD) should be carefully optimized. We fabricated diodes with various edge distances (slim-edge diodes) and with 1-3 multiple guard rings (multi-guard diodes). AC coupling insulators of strip sensors are vulnerable to sudden heavy charge deposition, such as an accidental beam splash, which may destroy the readout AC capacitors. Thus various types of punch-through-protection (PTP) structures were implemented in order to find the most effective structure to protect against heavy charge deposition. These samples were irradiated with 70 MeV protons at fluences of 5×1012 1 MeV neq/cm2-1×1016 1 MeV neq/cm2. Their performances were evaluated before and after irradiation in terms of an onset voltage of the MD, a turn-on voltage of the PTP, and PTP saturation resistance.
International Nuclear Information System (INIS)
Baek, Seung Se; Na, Sung Hun; Yu, Hyo Sun; Na, Eui Gyun
2001-01-01
In this study, a Small Punch Creep(SP-Creep) test using miniaturized specimen(10 x 10 x 0.5mm) is described to develop the new creep test method for high temperature structural materials. The SP-Creep test is applied to 2.25Cr-1Mo(STBA24) steel which is widely used as boiler tube material. The test temperatures applied for the creep deformation of miniaturized specimens are between 550∼600 .deg. C. The SP-Creep curves depend definitely on applied load and creep temperature, and show the three stages of creep behavior like in conventional uniaxial tensile creep curves. The load exponent of miniaturized specimen decrease with increasing test temperature, and its behavior is similar to stress exponent behavior of uniaxial creep test. The creep activation energy obtained from the relationship between SP-Creep rate and test temperature decreases as the applied load increases. A predicting equation of SP-Creep rate for 2.25Cr-1Mo steel is suggested, and a good agreement between experimental and calculated data has been found
Urban Heat Island Over Delhi Punches Holes in Widespread Fog in the Indo-Gangetic Plains
Gautam, Ritesh; Singh, Manoj K.
2018-01-01
Persistent and widespread fog affects several densely populated and agriculturally fertile basins around the world. Dense and polluted fog is especially known to impact transportation, air quality, and public health. Here we report a striking observation of holes in fog over urban areas in satellite imagery. The extent of fog holes appear highly correlated with city populations in fog-prevalent regions of Asia, Europe, and the United States. We find the highest frequency and largest extent of fog holes over Delhi along with suppressed fog fraction, amidst increased fog occurrence over the Indo-Gangetic Plains, based on 17 years of satellite data (2000-2016). This apparent urban heat impact is characterized in sharp urban-rural gradients in surface temperatures and fog thickness. Urban heating seems to have already amplified the long-term fog decline in Europe and the United States and should be assessed over regions undergoing urban expansion including India, where no previous linkages are reported between urban heating and fog.
Rossato, Luiz Angelo; Carneiro, Rachel Camargo; Macedo, Erick Marcet Santiago de; Lima, Patrícia Picciarelli de; Miyazaki, Ahlys Ayumi; Matayoshi, Suzana
2016-01-01
: to compare the accuracy of preoperative 2-mm punch biopsy at one site and at two sites in the diagnosis of aggressive subtypes of eyelid basal cell carcinoma (BCC). : we randomly assigned patients to Group 1 (biopsy at one site) and Group 2 (biopsy at two sites). We compared the biopsy results to the gold standard (pathology of the surgical specimen). We calculated the sensitivity, specificity, positive predictive value, negative predictive value, accuracy and Kappa coefficient to determine the level of agreement in both groups. : we analyzed 105 lesions (Group 1: n = 44; Group 2: n = 61). The agreement was 54.5% in Group 1 and 73.8% in Group 2 (p = 0.041). There was no significant difference between the groups regarding the distribution of quantitative and qualitative variables (gender, age, disease duration, tumor larger diameter, area and commitment of margins). Biopsy at two sites was two times more likely to agree with the gold standard than the biopsy of a single site. : the accuracy and the performance indicators were better for 2-mm punch biopsy in two sites than in one site for the diagnosis of aggressive subtypes of eyelid BCC. comparar a acurácia da biópsia pré-operatória por trépano de 2mm em um sítio e em dois sítios no diagnóstico dos subtipos agressivos de carcinoma basocelular (CBC) palpebral. os pacientes foram distribuídos aleatoriamente em Grupo 1 (biópsia em um sítio) e Grupo 2 (biópsia em dois sítios). Os resultados das biópsias foram comparados com o padrão-ouro (exame anatomopatológico da peça cirúrgica). A sensibilidade, especificidade, valor preditivo positivo, valor preditivo negativo, precisão e coeficiente Kappa foram calculados para determinar o nível de concordância nos dois grupos. foram analisadas 105 lesões (Grupo 1: n = 44; Grupo 2: n = 61). A concordância foi de 54,5% no Grupo 1 e 73,8% no Grupo 2 (p-valor = 0,041). Não houve diferença significativa entre os grupos quanto à distribuição das vari
Díaz Juárez, María Virginia
2017-01-01
Esta investigación tiene por objeto el estudio de la caricatura como género de opinión en la revista inglesa Punch, la estadounidense Puck y la uruguaya Caras y Caretas. Si bien pertenecen a distintos países, las tres fueron fundadas durante el siglo XIX. El trabajo presenta una aproximación a cómo las distintas publicaciones plasman los acontecimientos y personajes de la época por medio de la caricatura. Existe un gran valor testimonial en ellas que permite conocer la Historia desde otro lug...
Volkov, Sergei S.; Vasiliev, Andrey S.; Aizikovich, Sergei M.; Sadyrin, Evgeniy V.
2018-05-01
Indentation of an elastic half-space with functionally graded coating by a rigid flat punch is studied. The half-plane is additionally subjected to distributed tangential stresses. Tangential stresses are represented in a form of Fourier series. The problem is reduced to the solution of two dual integral equations over even and odd functions describing distribution of unknown normal contact stresses. The solutions of these dual integral equations are constructed by the bilateral asymptotic method. Approximated analytical expressions for contact normal stresses are provided.
Energy Technology Data Exchange (ETDEWEB)
Bruchhausen, M., E-mail: matthias.bruchhausen@ec.europa.eu [European Commission, Joint Research Centre, Institute for Energy and Transport, P.O. Box 2, 1755 ZG Petten (Netherlands); Turba, K. [European Commission, Joint Research Centre, Institute for Energy and Transport, P.O. Box 2, 1755 ZG Petten (Netherlands); Lund University, Division of Materials Engineering, P.O. Box 118, SE-221 00 Lund (Sweden); Haan, F. de; Hähner, P.; Austin, T. [European Commission, Joint Research Centre, Institute for Energy and Transport, P.O. Box 2, 1755 ZG Petten (Netherlands); Carlan, Y. de [CEA, DEN, Service de Recherches Métallurgiques Appliquées, 91191 Gif-sur-Yvette (France)
2014-01-15
A 14Cr ODS steel was characterized at elevated temperatures with regard to its behavior in small punch and uniaxial creep tests and in low cycle fatigue tests. A comparison of small punch and uniaxial creep tests at 650 °C revealed a strong anisotropy of the material when strained parallel and perpendicular to the extrusion direction with rupture times being several orders of magnitude lower for the perpendicular direction. The stress-rupture and Larson–Miller plots show a very large scatter of the creep data. This scatter is strongly reduced when rupture time is plotted against minimum deflection rate or minimum creep rate (Monkman–Grant plot). Fatigue tests have been carried out at 650 °C and 750 °C. The alloy is cyclically very stable with practically no hardening/softening. Results from the tests at both temperatures can be described by a common power law. An increase in the test temperature has little influence on the fatigue ductility exponent. For a given total strain level, the fatigue life of the alloy is reduced with increasing temperature.
Poley, Anne-luise; The ATLAS collaboration
2018-01-01
For the Phase-II Upgrade of the ATLAS detector, a new, all-silicon tracker will be constructed in order to cope with the increased track density and radiation level of the High-Luminosity Large Hadron Collider. While silicon strip sensors are designed to minimise the fraction of dead material and maximise the active area of a sensor, concessions must be made to the requirements of operating a sensor in a particle physics detector. Sensor geometry features like the punch-through protection deviate from the standard sensor architecture and thereby affect the charge collection in that area. In order to study the signal collection of silicon strip sensors over their punch-through-protection area, ATLAS silicon strip sensors were scanned with a micro-focused X-ray beam at the Diamond Light Source. Due to the highly focused X-ray beam ($\\unit[2\\times3]{\\upmu\\text{m}}^2$) and the short average path length of an electron after interaction with an X-ray photon ($\\unit[\\leq2]{\\upmu\\text{m}}$), local signal collection i...
International Nuclear Information System (INIS)
Kim, Do-Sik; Ahn, Sang-Bok; Yoo, Byung-Ok; Choo, Yong-Sun; Hong, Kwon-Pyo
2006-01-01
Miniaturized specimens have been widely used to evaluate the mechanical properties of steels and plastics. Especially for a study on the irradiation effects in nuclear materials, the small specimen test techniques have attracted considerable attention. Therefore, it is essential that the test techniques be developed and verified to extract the mechanical properties information from small specimens. Among the test techniques using small specimens, the small punch (SP) test technique using small disc-sized specimen has been successfully used to estimate the tensile properties (yield strength and ultimate tensile strength), DBTT (ductile-brittle transition temperature), fracture toughness and creep properties of metals irradiated in a reactor or a proton accelerator. In this paper, the existing SP test techniques are reviewed and summarized. In addition, the information on the development of the SP test procedure is obtained to evaluate the radiation effects on the mechanical properties of nuclear materials in a hot cell
Sharma, Ankush; Patnaik, Amar
2018-03-01
The present investigation evaluates the effects of waste marble dust, collected from the marble industries of Rajasthan, India, on the mechanical properties of needle-punched nonwoven jute fiber/epoxy composites. The composites with varying filler contents from 0 wt.% to 30 wt.% marble dust were prepared using vacuum-assisted resin-transfer molding. The influences of the filler material on the void content, tensile strength, flexural strength, interlaminar shear strength (ILSS), and thermal conductivity of the hybrid composites have been analyzed experimentally under the desired optimal conditions. The addition of marble dust up to 30 wt.% increases the flexural strength, ILSS, and thermal conductivity, but decreases the tensile strength. Subsequently, the fractured surfaces of the particulate-filled jute/epoxy composites were analyzed microstructurally by field-emission scanning electron microscopy.
Šašiċ, Slobodan; Ojakovo, Peter; Warman, Martin; Sanghvi, Tapan
2013-09-01
Raman chemical mapping was used to determine the distribution of magnesium stearate, a lubricant, on the surface of tablets. The lubrication was carried out via a punch-face lubrication system with different spraying rates applied on placebo and active-containing tablets. Principal component analysis was used for decomposing the matrix of Raman mapping spectra. Some of the loadings associated with minuscule variation in the data significantly overlap with the Raman spectrum of magnesium stearate in placebo tablets and allow for imaging the domains of magnesium stearate via corresponding scores. Despite the negligible variation accounted for by respective principal components, the score images seem reliable as demonstrated through thresholding the one-dimensional representation and the spectra of the hot pixels that show a weak but perceivable magnesium stearate band at 1295 cm(-1). The same approach was applied on the active formulation, but no magnesium stearate was identified, presumably due to overwhelming concentration and spectral contribution of the active pharmaceutical ingredient.
Institute of Scientific and Technical Information of China (English)
殷庆超; 廉有轩; 王恩营; 刘度
2015-01-01
End of the alley pumping wear layer drilling hydraulic punching pressure, the anti-reflection measures can effectively en-hance the permeability of coal seam, expanding radius of extraction and improve the effect of the gas extraction., on the basis of the principle of antireflection unloading hydraulic punching in for zhengzhou mining revitalization of two coal mine hydraulic punching plate wear layer, gas drainage concentration before and after the hydraulic punching, the change of coal seam permeability and the gas flow attenuation coefficient and so on.The test results show that the average single-hole gas drainage concentration is 11.02%, after hy-draulic punching is 2.14%, the anti-reflection measures of improve 4 times; Coefficient of permeability of coal seam after taking steps to improve the 39 times;The gas flow attenuation coefficient is reduced nearly 3 times.Using the method of pressure measured at the same time the mine hydraulic punching effective drainage radius to 10 m.%采用底抽巷穿层钻孔水力冲孔卸压增透措施，可以有效增强煤层的透气性、扩大抽采半径和提高瓦斯抽采效果。基于水力冲孔卸压增透原理，对郑州矿区振兴二矿突出煤层实施底板穿层水力冲孔，考察水力冲孔前后瓦斯抽放浓度、煤层透气性和瓦斯流量衰减系数等的变化。试验结果表明：单孔平均瓦斯抽放浓度在水力冲孔后为11．02％，较未采取增透措施时的2．14％，提高了4倍；煤层透气性系数在采取措施后提高了39倍；瓦斯流量衰减系数则减小了近3倍。同时运用压力法测得该矿水力冲孔有效抽放半径为10 m。
Directory of Open Access Journals (Sweden)
Douglas R Frabetti
2011-02-01
Full Text Available Realizou-se este trabalho com o objetivo de desenvolver uma semeadora pontual para o semeio de milho em sistema de plantio direto e avaliar seu sistema de dosagem e distribuição de sementes. Primeiro, elaborou-se uma lista de requisitos os quais a máquina deveria atender; depois, foi feito o projeto conceitual do corpo da máquina e, em seguida, o projeto detalhado de todas as partes e conjuntos, para posterior construção do protótipo. Em bancada de ensaio avaliou-se o desempenho do sistema dosador e distribuidor de sementes, em relação à variação da velocidade e da quantidade de punções utilizada. O delineamento experimental foi em blocos casualizados arranjados em parcelas subdivididas com a parcela principal composta por 6, 9 e 12 punções e a subparcela sendo quatro rotações da roda dosadora correspondentes às velocidades de deslocamento de 4, 6, 8 e 10 km h-1. De modo geral, tanto o aumento da velocidade como do número de punções nas rodas, diminuiu o número de duplas e aumentou o número de faltas, porém a diminuição do número de duplas não foi significativo quanto ao aumento do número de faltas. A semeadora exerceu desempenho satisfatório, com média geral do número de normais de 91%.The present work was accomplished to develop a punch planter to sow corn seeds in no-tillage system, and also to evaluate the performance of its seed metering and delivery systems. First of all, a requirement list was established, that the machine would have to attend. Next, the conceptual and the embodiment designs of the machine was made. Then, the detailed design of all machine parts was made and a prototype was constructed. In a testing bench the performance of the seed metering unit and its seed delivery system was assessed in relation to the punch wheel speed and the quantity of punches on the wheel. The statistical design was in random blocks arranged in sub-divided plots with the main plot made of 6, 9 and 12 punches and
Source-Drain Punch-Through Analysis of High Voltage Off-State AlGaN/GaN HEMT Breakdown
Jiang, H.; Li, X.; Wang, J.; Zhu, L.; Wang, H.; Liu, J.; Wang, M.; Yu, M.; Wu, W.; Zhou, Y.; Dai, G.
2017-06-01
AlGaN/GaN high-electron mobility transistor’s (HEMT’s) off-state breakdown is investigated using conventional three-terminal off-state breakdown I-V measurement. Competition between gate leakage and source-injection buffer leakage (SIBL) is discussed in detail. It is found that the breakdown is dominated by source-injection which is sensitive to gate voltage and gate length at large gate-to-drain spacing (Lgd > 7μm), where a threshold drain voltage of the occurrence of the SIBL current in GaN buffer exists, and after this threshold voltage the SIBL current continually increased till the buffer breakdown. Our analysis showed that due to the punch-through effect in the buffer, a potential barrier between 2DEG and GaN buffer at the source side mainly controlled by the drain voltage determines the buffer leakage current and the occurrence of the following buffer breakdown, which could explain the experimentally observed breakdown phenomenon.
Wold-Brennon, R.; Cooper, S. K.
2014-12-01
Through collaborations between scientists and educators, the Consortium for Ocean Leadership developed a series of marine geosciences classroom activities and lesson plans -- including the Adopt-a-Microbe project, a collection of hands-on science lessons that use the sub-seafloor microbiology topics to provide engaging pathways for K-12 students to learn about the world around them. The goal of these activities has been to introduce youth to deep ocean exploration, inspire interest in microbial oceanography, and foster higher education goals and career paths in related sciences for our youth. From the beginning, these lessons were developed in close working relationships between scientists and educators, and the lessons geared towards middle school have been recently piloted with the intent to maximize sustained student interest in STEM topics. While teaching these units, educators used surveys, polls, group discussions, and interviews to shed light on correlations between student interest in STEM and their close proximity to exemplary and enthusiastic educators and student leaders who are active in STEM activities such as research projects and expeditions. Educators continue to use Adopt-a-Microbe and related expedition science-based lessons to explore the broader impacts of their professional development in the Geosciences on their students' professed interest in STEM.
Horbert, Victoria; Xin, Long; Foehr, Peter; Brinkmann, Olaf; Bungartz, Matthias; Burgkart, Rainer H; Graeve, T; Kinne, Raimund W
2018-02-01
Objective Limitations of matrix-assisted autologous chondrocyte implantation to regenerate functional hyaline cartilage demand a better understanding of the underlying cellular/molecular processes. Thus, the regenerative capacity of a clinically approved hydrogel collagen type I implant was tested in a standardized bovine cartilage punch model. Methods Cartilage rings (outer diameter 6 mm; inner defect diameter 2 mm) were prepared from the bovine trochlear groove. Collagen implants (± bovine chondrocytes) were placed inside the cartilage rings and cultured up to 12 weeks. Cartilage-implant constructs were analyzed by histology (hematoxylin/eosin; safranin O), immunohistology (aggrecan, collagens 1 and 2), and for protein content, RNA expression, and implant push-out force. Results Cartilage-implant constructs revealed vital morphology, preserved matrix integrity throughout culture, progressive, but slight proteoglycan loss from the "host" cartilage or its surface and decreasing proteoglycan release into the culture supernatant. In contrast, collagen 2 and 1 content of cartilage and cartilage-implant interface was approximately constant over time. Cell-free and cell-loaded implants showed (1) cell migration onto/into the implant, (2) progressive deposition of aggrecan and constant levels of collagens 1 and 2, (3) progressively increased mRNA levels for aggrecan and collagen 2, and (4) significantly augmented push-out forces over time. Cell-loaded implants displayed a significantly earlier and more long-lasting deposition of aggrecan, as well as tendentially higher push-out forces. Conclusion Preserved tissue integrity and progressively increasing cartilage differentiation and push-out forces for up to 12 weeks of cultivation suggest initial cartilage regeneration and lateral bonding of the implant in this in vitro model for cartilage replacement materials.
International Nuclear Information System (INIS)
Giraud, B.G.; Heumann, J.M.; Lapedes, A.S.
1999-01-01
The fact that correlation does not imply causation is well known. Correlation between variables at two sites does not imply that the two sites directly interact, because, e.g., correlation between distant sites may be induced by chaining of correlation between a set of intervening, directly interacting sites. Such 'noncausal correlation' is well understood in statistical physics: an example is long-range order in spin systems, where spins which have only short-range direct interactions, e.g., the Ising model, display correlation at a distance. It is less well recognized that such long-range 'noncausal' correlations can in fact be stronger than the magnitude of any causal correlation induced by direct interactions. We call this phenomenon superadditive correlation (SAC). We demonstrate this counterintuitive phenomenon by explicit examples in (i) a model spin system and (ii) a model continuous variable system, where both models are such that two variables have multiple intervening pathways of indirect interaction. We apply the technique known as decimation to explain SAC as an additive, constructive interference phenomenon between the multiple pathways of indirect interaction. We also explain the effect using a definition of the collective mode describing the intervening spin variables. Finally, we show that the SAC effect is mirrored in information theory, and is true for mutual information measures in addition to correlation measures. Generic complex systems typically exhibit multiple pathways of indirect interaction, making SAC a potentially widespread phenomenon. This affects, e.g., attempts to deduce interactions by examination of correlations, as well as, e.g., hierarchical approximation methods for multivariate probability distributions, which introduce parameters based on successive orders of correlation. copyright 1999 The American Physical Society
Punch up your podium presentations.
Wood, Tim J; Hollier, Amelie
2017-08-01
The goal of most presentations is to engage audience participants. Effective presenters go beyond content expertise to connect with audiences through various techniques, formats, and presentation styles. Mayer's theory of multimedia learning, neurocognitive factors, and the assertion-evidence approach are essential elements that presenters can use if they have not had formal training in creating presentations. Tips are offered on how to connect with the audience and how to avoid known pitfalls. ©2017 American Association of Nurse Practitioners.
Sinclair, Michael B [Albuquerque, NM; Pfeifer, Kent B [Los Lunas, NM; Flemming, Jeb H [Albuquerque, NM; Jones, Gary D [Tijeras, NM; Tigges, Chris P [Albuquerque, NM
2010-04-13
A correlation spectrometer can detect a large number of gaseous compounds, or chemical species, with a species-specific mask wheel. In this mode, the spectrometer is optimized for the direct measurement of individual target compounds. Additionally, the spectrometer can measure the transmission spectrum from a given sample of gas. In this mode, infrared light is passed through a gas sample and the infrared transmission signature of the gasses present is recorded and measured using Hadamard encoding techniques. The spectrometer can detect the transmission or emission spectra in any system where multiple species are present in a generally known volume.
Institute of Scientific and Technical Information of China (English)
唐忠荣; 黄健; 戴玉玲; 丰江拓
2015-01-01
利用响应面法分析研究了经微孔处理后的杨木单板的胶合性能。通过对杨木单板进行微孔处理，可使胶黏剂通过微孔渗入单板体内，增加杨木单板的本体强度，同时也可使相邻胶层透过微孔形成一体而增加单板的胶合强度等，以期制造出一种高性能的地板基材。结果表明：在试验范围内，随微孔孔径增大，孔距减小和施胶量的增加，其胶合强度增加；随热压压力增加，胶合强度先增强，当压力超过0．8 MPa，胶合强度反而降低。%We studied the bonding properties of poplar veneer punched with micro-holes by using response surface experiment. The permeability of poplar veneer increased after micro-hole punching.The adhesive could penetrate into the veneer through these micro holes, and the poplar veneer was strengthened.Through micro holes, the neighboring glue lines formed a whole to increase the bonding strength of veneers.Expecting to produce a high performance floor material.The bonding strength of poplar plywood increased with the increasing of micro-hole diameter,resin content , and the decreasing of holes distance.With the increasing of hot pressing pressure, the bonding strength was improved firstly, however, it declined when the pressure exceeded 0.8 MPa.
Directory of Open Access Journals (Sweden)
Kong-Bing Tan
2013-01-01
Full Text Available Squamous cell carcinoma (SCC is a common and important primary cutaneous malignancy. On skin biopsies, SCC is characterized by significant squamous cell atypia, abnormal keratinization, and invasive features. Diagnostic challenges may occasionally arise, especially in the setting of small punch biopsies or superficial shave biopsies, where only part of the lesion may be assessable by the pathologist. Benign mimics of SCC include pseudoepitheliomatous hyperplasia, eccrine squamous syringometaplasia, inverted follicular keratosis, and keratoacanthoma, while malignant mimics of SCC include basal cell carcinoma, melanoma, and metastatic carcinoma. The careful application of time-honored diagnostic criteria, close clinicopathological correlation and a selective request for a further, deeper, or wider biopsy remain the most useful strategies to clinch the correct diagnosis. This review aims to present the key differential diagnoses of SCC, to discuss common diagnostic pitfalls, and to recommend ways to deal with diagnostically challenging cases.
Correlated binomial models and correlation structures
International Nuclear Information System (INIS)
Hisakado, Masato; Kitsukawa, Kenji; Mori, Shintaro
2006-01-01
We discuss a general method to construct correlated binomial distributions by imposing several consistent relations on the joint probability function. We obtain self-consistency relations for the conditional correlations and conditional probabilities. The beta-binomial distribution is derived by a strong symmetric assumption on the conditional correlations. Our derivation clarifies the 'correlation' structure of the beta-binomial distribution. It is also possible to study the correlation structures of other probability distributions of exchangeable (homogeneous) correlated Bernoulli random variables. We study some distribution functions and discuss their behaviours in terms of their correlation structures
International Nuclear Information System (INIS)
Tan, K. B.; Tan, S. H.; Lee, Y. S.; Wee Aw, D. C.; Jaffar, H.; Lim, T. C.; Lee, S. J.
2013-01-01
Squamous cell carcinoma (SCC) is a common and important primary cutaneous malignancy. On skin biopsies, SCC is characterized by significant squamous cell atypia, abnormal keratinisation, and invasive features. Diagnostic challenges may occasionally arise, especially in the setting of small punch biopsies or superficial shave biopsies, where only part of the lesion may be assessable by the pathologist. Benign mimics of SCC include pseudoepitheliomatous hyperplasia, eccrine squamous syringometaplasia, inverted follicular keratosis, and keratoacanthoma, while malignant mimics of SCC include basal cell carcinoma, melanoma, and metastatic carcinoma. The careful application of time-honored diagnostic criteria, close clinico pathological correlation and a selective request for a further, deeper, or wider biopsy remain the most useful strategies to clinch the correct diagnosis. This review aims to present the key differential diagnoses of SCC, to discuss common diagnostic pitfalls, and to recommend ways to deal with diagnostically challenging cases
Orthogonalization of correlated states
International Nuclear Information System (INIS)
Fantoni, S.; Pandharipande, V.R.
1988-01-01
A scheme for orthogonalizing correlated states while preserving the diagonal matrix elements of the Hamiltonian is developed. Conventional perturbation theory can be used with the orthonormal correlated basis obtained from this scheme. Advantages of using orthonormal correlated states in calculations of the response function and correlation energy are discussed
Geometric correlations and multifractals
International Nuclear Information System (INIS)
Amritkar, R.E.
1991-07-01
There are many situations where the usual statistical methods are not adequate to characterize correlations in the system. To characterize such situations we introduce mutual correlation dimensions which describe geometric correlations in the system. These dimensions allow us to distinguish between variables which are perfectly correlated with or without a phase lag, variables which are uncorrelated and variables which are partially correlated. We demonstrate the utility of our formalism by considering two examples from dynamical systems. The first example is about the loss of memory in chaotic signals and describes auto-correlations while the second example is about synchronization of chaotic signals and describes cross-correlations. (author). 19 refs, 6 figs
Photon correlation holography.
Naik, Dinesh N; Singh, Rakesh Kumar; Ezawa, Takahiro; Miyamoto, Yoko; Takeda, Mitsuo
2011-01-17
Unconventional holography called photon correlation holography is proposed and experimentally demonstrated. Using photon correlation, i.e. intensity correlation or fourth order correlation of optical field, a 3-D image of the object recorded in a hologram is reconstructed stochastically with illumination through a random phase screen. Two different schemes for realizing photon correlation holography are examined by numerical simulations, and the experiment was performed for one of the reconstruction schemes suitable for the experimental proof of the principle. The technique of photon correlation holography provides a new insight into how the information is embedded in the spatial as well as temporal correlation of photons in the stochastic pseudo thermal light.
Hadron correlations from recombination
Energy Technology Data Exchange (ETDEWEB)
Fries, Rainer J [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States)
2005-01-01
Quark recombination is a successful model to describe the hadronization of a deconfined quark gluon plasma. Jet-like dihadron correlations measured at RHIC provide a challenge for this picture. We discuss how correlations between hadrons can arise from correlations between partons before hadronization. An enhancement of correlations through the recombination process, similar to the enhancement of elliptic flow is found. Hot spots from completely or partially quenched jets are a likely source of such parton correlations.
WenJun Zhang; Xin Li
2015-01-01
Between-taxon interactions can be detected by calculating the sampling data of taxon sample type. In present study, Spearman rank correlation and proportion correlation are chosen as the general correlation measures, and their partial correlations are calculated and compared. The results show that for Spearman rank correlation measure, in all predicted candidate direct interactions by partial correlation, about 16.77% (x, 0-45.4%) of them are not successfully detected by Spearman rank correla...
Pairing correlations in nuclei
International Nuclear Information System (INIS)
Baba, C.V.K.
1988-01-01
There are many similarities between the properties of nucleons in nuclei and electrons in metals. In addition to the properties explainable in terms of independent particle motion, there are many important co-operative effects suggesting correlated motion. Pairing correlation which leads to superconductivity in metals and several important properties in nuclei , is an exmple of such correlations. An attempt has been made to review the effects of pairing correlations in nuclei. Recent indications of reduction in pairing correlations at high angular momenta is discussed. A comparision between pairing correlations in the cases of nuclei and electrons in metals is attempted. (author). 20 refs., 10 figs
Fracture toughness correlations
International Nuclear Information System (INIS)
Wallin, Kim
1986-09-01
In this study existing fracture parameter correlations are reviewed. Their applicability and reliability are discussed in detail. A new K IC -CVN-correlation, based on a theoretical brittle fracture model, is presented
International Nuclear Information System (INIS)
David, W.I.F.; Johnson, M.W.; Knowles, K.J.; Crosbie, G.D.; Graham, S.P.; Campbell, E.P.; Lyall, J.S.
1986-01-01
GENIE is a language for spectrum manipulation and display, that has been developed to satisfy the data-analysis requirements for all the neutron-scattering instruments at the spallation neutron source. The manual contains: the GENIE 'keyboard' commands, GENIE 'GCL' commands, command file examples, and the adding of non-standard facilities. (U.K.)
Another punch in the wall (Part 2)
Energy Technology Data Exchange (ETDEWEB)
Przhedetsky, B. [Rock Ignition Pty Ltd. (Australia)
2009-09-15
Based on feedback from readers to the story of coal mining extraction techniques in the July-August 2009 edition of this journal the overview is continued and more detail is given on certain methods and equipment used. Section headings are: draglines; bucket wheel excavators; truck and shovel; overburden slusher; and underground gasification.
Flexowriters, Punch Paper Poetry and Ontological Gaps
DEFF Research Database (Denmark)
Søndergaard, Morten
2013-01-01
What is an unheard avant-garde? Of course, the answer may be tautological: no one has ever heard of the unheard avant-garde, as it were. However, rumors and academic intuition has it that the archives are full of unheard stuff. And as everyone working with archives may tell you: the greatest thri...
Boxing headguard performance in punch machine tests.
McIntosh, Andrew S; Patton, Declan A
2015-09-01
The paper presents a novel laboratory method for assessing boxing headguard impact performance. The method is applied to examine the effects of headguards on head impact dynamics and injury risk. A linear impactor was developed, and a range of impacts was delivered to an instrumented Hybrid III head and neck system both with and without an AIBA (Association Internationale de Boxe Amateur)-approved headguard. Impacts at selected speeds between 4.1 and 8.3 m/s were undertaken. The impactor mass was approximately 4 kg and an interface comprising a semirigid 'fist' with a glove was used. The peak contact forces were in the range 1.9-5.9 kN. Differences in head impact responses between the Top Ten AIBA-approved headguard and bare headform in the lateral and forehead tests were large and/or significant. In the 8.3 m/s fist-glove impacts, the mean peak resultant headform accelerations for bare headform tests was approximately 130 g compared with approximately 85 g in the forehead impacts. In the 6.85 m/s bare headform impacts, mean peak resultant angular head accelerations were in the range of 5200-5600 rad/s(2) and almost halved by the headguard. Linear and angular accelerations in 45° forehead and 60° jaw impacts were reduced by the headguard. The data support the opinion that current AIBA headguards can play an important role in reducing the risk of concussion and superficial injury in boxing competition and training. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
International Nuclear Information System (INIS)
Ferguson, A.J.
1974-01-01
An outline of the theory of angular correlations is presented, and the difference between the modern density matrix method and the traditional wave function method is stressed. Comments are offered on particular angular correlation theoretical techniques. A brief discussion is given of recent studies of gamma ray angular correlations of reaction products recoiling with high velocity into vacuum. Two methods for optimization to obtain the most accurate expansion coefficients of the correlation are discussed. (1 figure, 53 references) (U.S.)
DEFF Research Database (Denmark)
Bysted, Tommy Kristensen; Hamila, R.; Gabbouj, M.
1998-01-01
A new correlation function called the Teager correlation function is introduced in this paper. The connection between this function, the Teager energy operator and the conventional correlation function is established. Two applications are presented. The first is the minimization of the Teager error...... norm and the second one is the use of the instantaneous Teager correlation function for simultaneous estimation of TDOA and FDOA (Time and Frequency Difference of Arrivals)....
Correlation in photodetachment
International Nuclear Information System (INIS)
Pegg, D.J.
1992-01-01
Electron correlation plays a major role in all aspects of the photodetachment of an electron from a negative ion. Photodetachment measurements are well suited to investigate the relatively short range forces associated with correlation due to the absence of the long range Coulomb interaction. Measurements of electron affinities, asymmetry parameters and cross sections are described to illustrate the influence of correlation on photodetachment
Correlating P-wave Velocity with the Physico-Mechanical Properties of Different Rocks
Khandelwal, Manoj
2013-04-01
In mining and civil engineering projects, physico-mechanical properties of the rock affect both the project design and the construction operation. Determination of various physico-mechanical properties of rocks is expensive and time consuming, and sometimes it is very difficult to get cores to perform direct tests to evaluate the rock mass. The purpose of this work is to investigate the relationships between the different physico-mechanical properties of the various rock types with the P-wave velocity. Measurement of P-wave velocity is relatively cheap, non-destructive and easy to carry out. In this study, representative rock mass samples of igneous, sedimentary, and metamorphic rocks were collected from the different locations of India to obtain an empirical relation between P-wave velocity and uniaxial compressive strength, tensile strength, punch shear, density, slake durability index, Young's modulus, Poisson's ratio, impact strength index and Schmidt hammer rebound number. A very strong correlation was found between the P-wave velocity and different physico-mechanical properties of various rock types with very high coefficients of determination. To check the sensitivity of the empirical equations, Students t test was also performed, which confirmed the validity of the proposed correlations.
International Nuclear Information System (INIS)
Ozawa, Masanao
2006-01-01
The notion of perfect correlations between arbitrary observables, or more generally arbitrary POVMs, is introduced in the standard formulation of quantum mechanics, and characterized by several well-established statistical conditions. The transitivity of perfect correlations is proved to generally hold, and applied to a simple articulation for the failure of Hardy's nonlocality proof for maximally entangled states. The notion of perfect correlations between observables and POVMs is used for defining the notion of a precise measurement of a given observable in a given state. A longstanding misconception on the correlation made by the measuring interaction is resolved in the light of the new theory of quantum perfect correlations
International Nuclear Information System (INIS)
Luo Shunlong; Li Nan
2008-01-01
Werner states are paradigmatic examples of quantum states and play an innovative role in quantum information theory. In investigating the correlating capability of Werner states, we find the curious phenomenon that quantum correlations, as quantified by the entanglement of formation, may exceed the total correlations, as measured by the quantum mutual information. Consequently, though the entanglement of formation is so widely used in quantifying entanglement, it cannot be interpreted as a consistent measure of quantum correlations per se if we accept the folklore that total correlations are measured (or rather upper bounded) by the quantum mutual information.
Correlation in atomic scattering
International Nuclear Information System (INIS)
McGuire, J.H.
1987-01-01
Correlation due to the Coulomb interactions between electrons in many-electron targets colliding with charged particles is formulated, and various approximate probability amplitudes are evaluated. In the limit that the electron-electron, 1/r/sub i//sub j/, correlation interactions are ignored or approximated by central potentials, the independent-electron approximation is obtained. Two types of correlations, or corrections to the independent-electron approximation due to 1/r/sub i//sub j/ terms, are identified: namely, static and scattering correlation. Static correlation is that contained in the asymptotic, e.g., bound-state, wave functions. Scattering correlation, arising from correlation in the scattering operator, is new and is considered in some detail. Expressions for a scattering correlation amplitude, static correlation or rearrangement amplitude, and independent-electron or direct amplitude are derived at high collision velocity and compared. At high velocities the direct and rearrangement amplitudes dominate. At very high velocities, ν, the rearrangement amplitude falls off less rapidly with ν than the direct amplitude which, however, is dominant as electron-electron correlation tends to zero. Comparisons with experimental observations are discussed
Correlation in photodetachment
International Nuclear Information System (INIS)
Pegg, D.J.; Tennessee Univ., Knoxville, TN
1991-01-01
Electron correlation plays a major role in all aspects of the photodetachment of an electron from a negative ion. Photodetachment measurements are well suited to investigate the relatively short range forces associated with correlation due to the absence of the long range Coulomb interaction. Measurements of electron affinities, asymmetry parameters and cross sections are described to illustrate the influence of correlation on photodetachment. 25 refs., 4 figs
Intercorporate Security Event Correlation
Directory of Open Access Journals (Sweden)
D. O. Kovalev
2010-03-01
Full Text Available Security controls are prone to false positives and false negatives which can lead to unwanted reputation losses for the bank. The reputational database within the security operations center (SOC and intercorporate correlation of security events are offered as a solution to increase attack detection fidelity. The theses introduce the definition and structure of the reputation, architectures of reputational exchange and the place of intercorporate correlation in overall SOC correlation analysis.
RHIC Data Correlation Methodology
International Nuclear Information System (INIS)
Michnoff, R.; D'Ottavio, T.; Hoff, L.; MacKay, W.; Satogata, T.
1999-01-01
A requirement for RHIC data plotting software and physics analysis is the correlation of data from all accelerator data gathering systems. Data correlation provides the capability for a user to request a plot of multiple data channels vs. time, and to make meaningful time-correlated data comparisons. The task of data correlation for RHIC requires careful consideration because data acquisition triggers are generated from various asynchronous sources including events from the RHIC Event Link, events from the two Beam Sync Links, and other unrelated clocks. In order to correlate data from asynchronous acquisition systems a common time reference is required. The RHIC data correlation methodology will allow all RHIC data to be converted to a common wall clock time, while still preserving native acquisition trigger information. A data correlation task force team, composed of the authors of this paper, has been formed to develop data correlation design details and provide guidelines for software developers. The overall data correlation methodology will be presented in this paper
Learning efficient correlated equilibria
Borowski, Holly P.; Marden, Jason R.; Shamma, Jeff S.
2014-01-01
The majority of distributed learning literature focuses on convergence to Nash equilibria. Correlated equilibria, on the other hand, can often characterize more efficient collective behavior than even the best Nash equilibrium. However, there are no existing distributed learning algorithms that converge to specific correlated equilibria. In this paper, we provide one such algorithm which guarantees that the agents' collective joint strategy will constitute an efficient correlated equilibrium with high probability. The key to attaining efficient correlated behavior through distributed learning involves incorporating a common random signal into the learning environment.
Learning efficient correlated equilibria
Borowski, Holly P.
2014-12-15
The majority of distributed learning literature focuses on convergence to Nash equilibria. Correlated equilibria, on the other hand, can often characterize more efficient collective behavior than even the best Nash equilibrium. However, there are no existing distributed learning algorithms that converge to specific correlated equilibria. In this paper, we provide one such algorithm which guarantees that the agents\\' collective joint strategy will constitute an efficient correlated equilibrium with high probability. The key to attaining efficient correlated behavior through distributed learning involves incorporating a common random signal into the learning environment.
Kress, Thomas
2002-01-01
Particle correlations are extensively studied to obtain information about the dynamics of hadron production. From 1989 to 2000 the four LEP collaborations recorded more than 16 million hadronic Z0 decays and several thousand W+W- events. In Z0 decays, two-particle correlations were analysed in detail to study Bose-Einstein and Fermi-Dirac correlations for various particle species. In fully-hadronic W+W- decays, particle correlations were used to study whether the two W bosons decay independently. A review of selected results is presented.
Directory of Open Access Journals (Sweden)
Jauberthie R.
2012-09-01
test specimens in the presence of a propane flame. The fibre-reinforced mortar is subjected to the flame on one face; the evolution of the temperature gradient is followed in time. The influence of fibre type is quantified. The cracks appear both on the side exposed to the flame but also, and to a lesser extent on the cold face. After a certain exposure time, the mechanical properties are compared. A mechanical test was developed to determine the influence of cracking on the punching strength. The role of fibres, by their nature and by their position relative to the hot face is analysed. When the plates tested are designed with a low water to cement ratio, the phenomenon of spailling appears. The intensity of this phenomenon varies with the nature of the fibering.
International Nuclear Information System (INIS)
Zalewski, Kacper
2000-01-01
The effect of Bose-Einstein correlations on multiplicity distributions of identical pions is discussed. It is found that these correlations affect significantly the observed multiplicity distributions, but Einstein's condensation is unlikely to be achieved, unless 'cold spots', i.e. regions, where groups of pions with very small relative momenta are produced, occur in high energy heavy-ion collisions
This patent describes a low offset AC correlator avoids DC offset and low frequency noise by frequency operating the correlation signal so that low...noise, low level AC amplification can be substituted for DC amplification. Subsequently, the high level AC signal is demodulated to a DC level. (Author)
Correlates of Academic Procrastination.
Milgram, Norman A.; And Others
1993-01-01
Investigated concurrent correlates of academic procrastination in Israeli college preparatory students (n=113). Procrastination in one course of study was found to be moderately correlated with procrastination in another but not to procrastination in routine tasks of daily living. Procrastination was weakly related to emotional upset about it and…
Long sequence correlation coprocessor
Gage, Douglas W.
1994-09-01
A long sequence correlation coprocessor (LSCC) accelerates the bitwise correlation of arbitrarily long digital sequences by calculating in parallel the correlation score for 16, for example, adjacent bit alignments between two binary sequences. The LSCC integrated circuit is incorporated into a computer system with memory storage buffers and a separate general purpose computer processor which serves as its controller. Each of the LSCC's set of sequential counters simultaneously tallies a separate correlation coefficient. During each LSCC clock cycle, computer enable logic associated with each counter compares one bit of a first sequence with one bit of a second sequence to increment the counter if the bits are the same. A shift register assures that the same bit of the first sequence is simultaneously compared to different bits of the second sequence to simultaneously calculate the correlation coefficient by the different counters to represent different alignments of the two sequences.
International Nuclear Information System (INIS)
Iqbal, Azhar; Weigert, Stefan
2004-01-01
A new approach to play games quantum mechanically is proposed. We consider two players who perform measurements in an EPR-type setting. The payoff relations are defined as functions of correlations, i.e. without reference to classical or quantum mechanics. Classical bi-matrix games are reproduced if the input states are classical and perfectly anti-correlated, that is, for a classical correlation game. However, for a quantum correlation game, with an entangled singlet state as input, qualitatively different solutions are obtained. For example, the Prisoners' Dilemma acquires a Nash equilibrium if both players apply a mixed strategy. It appears to be conceptually impossible to reproduce the properties of quantum correlation games within the framework of classical games
International Nuclear Information System (INIS)
Shimizu, Yoshifumi
2009-01-01
Except for the closed shell nuclei, almost all nuclei are in the superconducting state at their ground states. This well-known pair correlation in nuclei causes various interesting phenomena. It is especially to be noted that the pair correlation becomes weak in the excited states of nuclei with high angular momentum, which leads to the pair phase transition to the normal state in the high spin limit. On the other hand, the pair correlation becomes stronger in the nuclei with lower nucleon density than in those with normal density. In the region of neutron halo or skin state of unstable nuclei, this phenomenon is expected to be further enhanced to be observed compared to the ground state of stable nuclei. An overview of those interesting aspects caused via the pair correlation is presented here in the sections titled 'pair correlations in ground states', pair correlations in high spin states' and 'pair correlations in unstable nuclei' focusing on the high spin state. (S. Funahashi)
Particle correlations at ALICE
Energy Technology Data Exchange (ETDEWEB)
Erazmus, B.; Lednicky, R.; Lyuboshitz, V.; Martin, L.; Mikhailov, K.; Pluta, J.; Sinyukov, Yu.; Stavinsky, A.; Werner, K
1998-12-31
The ability of the ALICE detector for determination of the space-time characteristics of particle production in heavy-ion collisions at LHC from measurements of the correlation functions of identical and non-identical particles at small relative velocities is discussed. The possibility to use the correlations of non-identical particles for a direct determination of the delays in emission of various particle species at time scales as small as 10{sup -23} s is demonstrated. The influence of the multi-boson effects on pion multiplicities, single-pion spectra and two-pion correlation functions is discussed. (author) 63 refs.
Spectral analysis by correlation
International Nuclear Information System (INIS)
Fauque, J.M.; Berthier, D.; Max, J.; Bonnet, G.
1969-01-01
The spectral density of a signal, which represents its power distribution along the frequency axis, is a function which is of great importance, finding many uses in all fields concerned with the processing of the signal (process identification, vibrational analysis, etc...). Amongst all the possible methods for calculating this function, the correlation method (correlation function calculation + Fourier transformation) is the most promising, mainly because of its simplicity and of the results it yields. The study carried out here will lead to the construction of an apparatus which, coupled with a correlator, will constitute a set of equipment for spectral analysis in real time covering the frequency range 0 to 5 MHz. (author) [fr
Interelement correlations in plants
International Nuclear Information System (INIS)
Markert, B.
1987-01-01
The concentration of 25 elements in 4 plant species (Citrus aurantia, Brassica oleracea, Lycopersicon esculentum and Pinus strobus) were linearly correlated. For some element pairs (Ce-Fe, Ce-Ni, Ce-Sb, Ce-Sc, Ce-Zn, Fe-Sb, Fe-Sc, Fe-U, Fe-Zn, K-Cd, La-U, Ni-Sb, Sc-U and Sc-Zn) a high positive correlation coefficient (r = +1) was found. The element pairs Ca-Mg, Hg-U, Ni-Sr and Sr-Zn show a significant negative correlation (r = -1). Plants seem to process some constant interelement relations, independent of plant species. (orig.)
Rotationally invariant correlation filtering
International Nuclear Information System (INIS)
Schils, G.F.; Sweeney, D.W.
1985-01-01
A method is presented for analyzing and designing optical correlation filters that have tailored rotational invariance properties. The concept of a correlation of an image with a rotation of itself is introduced. A unified theory of rotation-invariant filtering is then formulated. The unified approach describes matched filters (with no rotation invariance) and circular-harmonic filters (with full rotation invariance) as special cases. The continuum of intermediate cases is described in terms of a cyclic convolution operation over angle. The angular filtering approach allows an exact choice for the continuous trade-off between loss of the correlation energy (or specificity regarding the image) and the amount of rotational invariance desired
Entropic Nonsignaling Correlations.
Chaves, Rafael; Budroni, Costantino
2016-06-17
We introduce the concept of entropic nonsignaling correlations, i.e., entropies arising from probabilistic theories that are compatible with the fact that we cannot transmit information instantaneously. We characterize and show the relevance of these entropic correlations in a variety of different scenarios, ranging from typical Bell experiments to more refined descriptions such as bilocality and information causality. In particular, we apply the framework to derive the first entropic inequality testing genuine tripartite nonlocality in quantum systems of arbitrary dimension and also prove the first known monogamy relation for entropic Bell inequalities. Further, within the context of complex Bell networks, we show that entropic nonlocal correlations can be activated.
Hadronic Correlations and Fluctuations
Energy Technology Data Exchange (ETDEWEB)
Koch, Volker
2008-10-09
We will provide a review of some of the physics which can be addressed by studying fluctuations and correlations in heavy ion collisions. We will discuss Lattice QCD results on fluctuations and correlations and will put them into context with observables which have been measured in heavy-ion collisions. Special attention will be given to the QCD critical point and the first order co-existence region, and we will discuss how the measurement of fluctuations and correlations can help in an experimental search for non-trivial structures in the QCD phase diagram.
Extractable Work from Correlations
Directory of Open Access Journals (Sweden)
Martí Perarnau-Llobet
2015-10-01
Full Text Available Work and quantum correlations are two fundamental resources in thermodynamics and quantum information theory. In this work, we study how to use correlations among quantum systems to optimally store work. We analyze this question for isolated quantum ensembles, where the work can be naturally divided into two contributions: a local contribution from each system and a global contribution originating from correlations among systems. We focus on the latter and consider quantum systems that are locally thermal, thus from which any extractable work can only come from correlations. We compute the maximum extractable work for general entangled states, separable states, and states with fixed entropy. Our results show that while entanglement gives an advantage for small quantum ensembles, this gain vanishes for a large number of systems.
Multibin Correlations: A Summary
International Nuclear Information System (INIS)
Bialas, A.; Zalewski, K.
2011-01-01
A recently proposed method of studying the long-range correlations in multiparticle production is described. It is explained how it can be used in practice to uncover the mechanisms of particle production in high energy collisions. (authors)
Principles of correlation counting
International Nuclear Information System (INIS)
Mueller, J.W.
1975-01-01
A review is given of the various applications which have been made of correlation techniques in the field of nuclear physics, in particular for absolute counting. Whereas in most cases the usual coincidence method will be preferable for its simplicity, correlation counting may be the only possible approach in such cases where the two radiations of the cascade cannot be well separated or when there is a longliving intermediate state. The measurement of half-lives and of count rates of spurious pulses is also briefly discussed. The various experimental situations lead to different ways the correlation method is best applied (covariance technique with one or with two detectors, application of correlation functions, etc.). Formulae are given for some simple model cases, neglecting dead-time corrections
DEFF Research Database (Denmark)
Angelsky, Oleg V.; Gbur, Gregory J.; Polyanskii, Peter
2012-01-01
This feature issue of Applied Optics contains a series of selected papers reflecting the state-of-the-art of correlation optics and showing synergetics between the theoretical background and experimental techniques.......This feature issue of Applied Optics contains a series of selected papers reflecting the state-of-the-art of correlation optics and showing synergetics between the theoretical background and experimental techniques....
Galaxy correlations and cosmology
International Nuclear Information System (INIS)
Fall, S.M.
1979-01-01
Correlations in the distribution of galaxies provide some important clues about the structure and evolution of the Universe on scales larger than individual galaxies. In recent years much effort has been devoted to estimating and interpreting galaxy correlations. This is a review of these efforts. It is meant to provide both an introductory overview of the subject and a critical assessment of some recent developments
Exponential smoothing weighted correlations
Pozzi, F.; Di Matteo, T.; Aste, T.
2012-06-01
In many practical applications, correlation matrices might be affected by the "curse of dimensionality" and by an excessive sensitiveness to outliers and remote observations. These shortcomings can cause problems of statistical robustness especially accentuated when a system of dynamic correlations over a running window is concerned. These drawbacks can be partially mitigated by assigning a structure of weights to observational events. In this paper, we discuss Pearson's ρ and Kendall's τ correlation matrices, weighted with an exponential smoothing, computed on moving windows using a data-set of daily returns for 300 NYSE highly capitalized companies in the period between 2001 and 2003. Criteria for jointly determining optimal weights together with the optimal length of the running window are proposed. We find that the exponential smoothing can provide more robust and reliable dynamic measures and we discuss that a careful choice of the parameters can reduce the autocorrelation of dynamic correlations whilst keeping significance and robustness of the measure. Weighted correlations are found to be smoother and recovering faster from market turbulence than their unweighted counterparts, helping also to discriminate more effectively genuine from spurious correlations.
Directory of Open Access Journals (Sweden)
Alexander V. Perig
2017-11-01
Full Text Available Minimization of the dead zone (DZA in the process of material forming is a materials science problem. Geometric and kinematic approaches to the minimization of the DZA during Equal Channel Angular Extrusion (ECAE have been proposed, developed, analyzed, and documented. The present article is focused on a 2D Computational Fluid Dynamics (CFD description of the kinematic effects of punch shape geometry and inlet (IDW and outlet (ODW die wall motion on the DZA during ECAE of Viscous Incompressible Continuum (VIC through a Segal 2θ-die for a range of channel angles 60° ≤ 2θ ≤ 135°. Due attention has been given to the independent alternating transport motions of the IDW and ODW. Punch shape geometry and the kinematic modes of IDW and ODW motions for DZA minimization have been determined with a numerical solution of the boundary value problem for the Navier-Stokes equations in curl transfer form for VIC. Experimental verification was accomplished with an introduction of initial circular gridlines-based physical simulation techniques. For the first time, experimental verification of CFD-derived results was made through an additional superposition of empirically-derived digital photos with deformed elliptical gridlines in the channel intersection deformation zones and correspondent 2D numerical plots with CFD-derived flow lines and full flow velocities. An empirical DZA localization was experimentally determined as the location of minimally-deformed near circular markers. The computational DZA localization was numerically determined as a flow-lines-free zone (the first hypothesis or as a zone with near-zero values of full flow velocities (the second hypothesis. The relative DZA was estimated as a ratio of the measured DZA with respect to the area of the deformation zone in the channel intersection region. A good agreement was obtained between DZA values obtained with the first hypothesis and experimental results.
Structure correlation and chemistry
International Nuclear Information System (INIS)
Buergi, H.B.
1998-01-01
The main goal of crystal and molecular structure determination is to provide a starting point for understanding the physical, chemical and biological properties of matter. At present, results from nearly 300000 crystal structure studies are available in computer-readable form. Structure correlation attempts to extract knowledge and understanding from this body of information, which is not available from its parts. This article reviews some typical examples: libraries of prototypal molecular dimensions, mappings of chemical reaction pathways, correlations between structure on one hand and energy, reaction rate, catalytic activity or magnetism on the other. The knowledge gained from structure-correlation studies, together with quantum-chemical and other modeling techniques, provides conceptual and practical tools for designing molecules and materials with tailor-made properties. (orig.)
Pair Correlation Function Integrals
DEFF Research Database (Denmark)
Wedberg, Nils Hejle Rasmus Ingemar; O'Connell, John P.; Peters, Günther H.J.
2011-01-01
We describe a method for extending radial distribution functions obtained from molecular simulations of pure and mixed molecular fluids to arbitrary distances. The method allows total correlation function integrals to be reliably calculated from simulations of relatively small systems. The long......-distance behavior of radial distribution functions is determined by requiring that the corresponding direct correlation functions follow certain approximations at long distances. We have briefly described the method and tested its performance in previous communications [R. Wedberg, J. P. O’Connell, G. H. Peters......, and J. Abildskov, Mol. Simul. 36, 1243 (2010); Fluid Phase Equilib. 302, 32 (2011)], but describe here its theoretical basis more thoroughly and derive long-distance approximations for the direct correlation functions. We describe the numerical implementation of the method in detail, and report...
DEFF Research Database (Denmark)
Finucane, F; Luan, J; Wareham, N
2009-01-01
(M/I) from hyperinsulinaemic-euglycaemic clamp studies in 1,226 EGIR RISC participants. RESULTS: The LAR was highly correlated with HOMA-S in men (r = -0.58, p = 4.5 x 10(-33) and r = -0.65, p = 1.1 x 10(-66) within the Ely and EGIR RISC study cohorts, respectively) and in women (r = -0.51, p = 2.8 x...... 10(-36) and r = -0.61, p = 2.5 x 10(-73)). The LAR was also strongly correlated with the clamp M/I value (r = -0.52, p = 4.5 x 10(-38) and r = -0.47, p = 6.6 x 10(-40) in men and women, respectively), similar to correlations between HOMA-S and the M/I value. CONCLUSIONS/INTERPRETATION: The leptin...
International Nuclear Information System (INIS)
Wong, Alexander; Glaister, Jeffrey; Cameron, Andrew; Haider, Masoom
2013-01-01
Prostate cancer is one of the leading causes of cancer death in the male population. Fortunately, the prognosis is excellent if detected at an early stage. Hence, the detection and localization of prostate cancer is crucial for diagnosis, as well as treatment via targeted focal therapy. New imaging techniques can potentially be invaluable tools for improving prostate cancer detection and localization. In this study, we introduce a new form of diffusion magnetic resonance imaging called correlated diffusion imaging, where the tissue being imaged is characterized by the joint correlation of diffusion signal attenuation across multiple gradient pulse strengths and timings. By taking into account signal attenuation at different water diffusion motion sensitivities, correlated diffusion imaging can provide improved delineation between cancerous tissue and healthy tissue when compared to existing diffusion imaging modalities. Quantitative evaluation using receiver operating characteristic (ROC) curve analysis, tissue class separability analysis, and visual assessment by an expert radiologist were performed to study correlated diffusion imaging for the task of prostate cancer diagnosis. These results are compared with that obtained using T2-weighted imaging and standard diffusion imaging (via the apparent diffusion coefficient (ADC)). Experimental results suggest that correlated diffusion imaging provide improved delineation between healthy and cancerous tissue and may have potential as a diagnostic tool for cancer detection and localization in the prostate gland. A new form of diffusion magnetic resonance imaging called correlated diffusion imaging (CDI) was developed for the purpose of aiding radiologists in cancer detection and localization in the prostate gland. Preliminary results show CDI shows considerable promise as a diagnostic aid for radiologists in the detection and localization of prostate cancer
DEFF Research Database (Denmark)
Asness, Clifford S.; Frazzini, Andrea; Gormsen, Niels Joachim
We test whether the low-risk effect is driven by (a) leverage constraints and thus risk should be measured using beta vs. (b) behavioral effects and thus risk should be measured by idiosyncratic risk. Beta depends on volatility and correlation, where only volatility is related to idiosyncratic risk....... Hence, the new factor betting against correlation (BAC) is particularly suited to differentiating between leverage constraints vs. lottery explanations. BAC produces strong performance in the US and internationally, supporting leverage constraint theories. Similarly, we construct the new factor SMAX...
Correlation ion mobility spectroscopy
Pfeifer, Kent B [Los Lunas, NM; Rohde, Steven B [Corrales, NM
2008-08-26
Correlation ion mobility spectrometry (CIMS) uses gating modulation and correlation signal processing to improve IMS instrument performance. Closely spaced ion peaks can be resolved by adding discriminating codes to the gate and matched filtering for the received ion current signal, thereby improving sensitivity and resolution of an ion mobility spectrometer. CIMS can be used to improve the signal-to-noise ratio even for transient chemical samples. CIMS is especially advantageous for small geometry IMS drift tubes that can otherwise have poor resolution due to their small size.
Multiparticle azimuthal correlations
Indian Academy of Sciences (India)
In §2, we recall the definition of elliptic flow and explain the mechanism producing ..... Taking this effect into account, one is led to revise significantly the values of the ... non-flow correlations, one can show under very general assumptions that ...
Clustering of correlated networks
Dorogovtsev, S. N.
2003-01-01
We obtain the clustering coefficient, the degree-dependent local clustering, and the mean clustering of networks with arbitrary correlations between the degrees of the nearest-neighbor vertices. The resulting formulas allow one to determine the nature of the clustering of a network.
Multiplicities and Correlations at LEP
International Nuclear Information System (INIS)
Sarkisyan, E.K.G.
2002-01-01
A brief review on recent charge multiplicity and correlation measurements at LEP is given. The measurements of un biased gluon jet multiplicity are discussed. Recent results on charged particle Bose-Einstein and Fermi-Dirac correlations at LEP1 are reported. New results on two-particle correlations of neutral pions are given. Correlations of more than two particles (high-order correlations) obtained using different methods are performed. Recent Bose-Einstein correlation measurements at LEP2 are discussed. (author)
Multiplicities and correlations at LEP
Sarkisyan-Grinbaum, E
2002-01-01
A brief review on recent charge multiplicity and correlation measurements at LEP is given. The measurements of unbiased gluon jet multiplicity are discussed. Recent results on charged particle Bose- Einstein and Fermi-Dirac correlations at LEP1. are reported. New results on two-particle correlations of neutral pions are given. Correlations of more than two particles (high-order correlations) obtained using different methods are performed. Recent Bose-Einstein correlation measurements at LEP2 are discussed. (13 refs).
Leck, Kira
2006-10-01
Researchers have associated minimal dating with numerous factors. The present author tested shyness, introversion, physical attractiveness, performance evaluation, anxiety, social skill, social self-esteem, and loneliness to determine the nature of their relationships with 2 measures of self-reported minimal dating in a sample of 175 college students. For women, shyness, introversion, physical attractiveness, self-rated anxiety, social self-esteem, and loneliness correlated with 1 or both measures of minimal dating. For men, physical attractiveness, observer-rated social skill, social self-esteem, and loneliness correlated with 1 or both measures of minimal dating. The patterns of relationships were not identical for the 2 indicators of minimal dating, indicating the possibility that minimal dating is not a single construct as researchers previously believed. The present author discussed implications and suggestions for future researchers.
Strain Induced Adatom Correlations
Kappus, Wolfgang
2012-01-01
A Born-Green-Yvon type model for adatom density correlations is combined with a model for adatom interactions mediated by the strain in elastic anisotropic substrates. The resulting nonlinear integral equation is solved numerically for coverages from zero to a limit given by stability constraints. W, Nb, Ta and Au surfaces are taken as examples to show the effects of different elastic anisotropy regions. Results of the calculation are shown by appropriate plots and discussed. A mapping to sup...
DEFF Research Database (Denmark)
Kock, Carsten Weber; Vesth, Allan
The report describes measurements carried out on a given wind turbine. A comparison between wind speed on the metmast and Nacelle Windspeed are made and the results are presented on graphs and in a table. The data used for the comparison are identical with the data used for the Risø-I-3246(EN) po......) power curve report. The measurements are carried out in accordance to Ref. [1] and the wind and yaw correlation is analyzed in accordance to Ref. [2]....
Clinicohistopathological correlation of leprosy
Directory of Open Access Journals (Sweden)
A Shrestha
2017-03-01
Full Text Available BACKGROUND: Leprosy is a chronic infectious granulomatous disease caused by Mycobacterium leprae. It is a spectral disease which is classified into five groups according to Ridley and Jopling based on clinical, histological, microbiological and immunological criteria. Adequate clinical information combined with bacilloscopy and histopathology is helpful not only in classification of different types of leprosy but also useful for management of the cases.METHOD: 50 cases of leprosy were examined and clinical data was recorded. Slit skin smears were stained with Ziehl Neelsen stain. Skin biopsy was stained with Hematoxylin-Eosin stain and Fite Farraco stain was performed to demonstrate acid fast bacilli. All patients were classified according to Ridley & Jopling classification. Clinico-histopathological correlation was done. Statistical analysis was done using SPSS (Statistical Package for the Social Sciences 16.0.RESULTS: Most common histological type of leprosy was tuberculoid leprosy seen in 19(38% cases followed by indeterminate leprosy. Overall clinico-histopathological correlation was seen in 39.58%. The correlation was highest in indeterminate and histoid leprosy (100% followed by lepromatous leprosy (66.66 %% and tuberculoid leprosy (50%. Slit skin smear showed bacilli in 12 out of 48 cases (25% while biopsy showed bacilli in 16 out of 48 cases (33.3%.CONCLUSION: In the present study, clinical diagnosis did not correlate with histopathological diagnosis significantly (p value=0.04159. The study emphasizes the role of histopathological and bacilloscopic examination to aid the clinical diagnosis for accurate typing of leprosy cases then better management of the patient.
International Nuclear Information System (INIS)
Fabris, J.D.
1977-01-01
The electric quadrupolar interaction in some hafnium complexes, measured at the metal nucleus level is studied. For that purpose, the technique of γ-γ perturbed angular correlation is used: the frequencies of quadrupolar interaction are compared with some hafnium α-hydroxicarboxilates, namely glycolate, lactate, mandelate and benzylate; the influence of the temperature on the quadrupolar coupling on the hafnium tetramandelate is studied; finally, the effects associated with the capture of thermal neutrons by hafnium tetramandelate are examined locally at the nuclear level. The first group of results shows significant differences in a series of complexes derived from glycolic acid. On the other hand, the substitution of the protons in hafnium tetramandelate structure by some alkaline cations permits to verify a correlation between the variations in the quadrupolar coupling and the electronegativities of the substituent elements. Measurements at high temperatures show that this complex is thermally stable at 100 and 150 0 C. It is possible to see the appearance of two distinct sites for the probe nucleus, after heating the sample at 100 0 C for prolonged time. This fact is attributed to a probable interconversion among the postulated structural isomers for the octacoordinated compounds. Finally, measurements of angular correlation on the irradiated complex show that there is an effective destruction of the target molecule by neutron capture [pt
Energy Technology Data Exchange (ETDEWEB)
Zou, Ling [Idaho National Lab. (INL), Idaho Falls, ID (United States); Berry, R. A. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Martineau, R. C. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Andrs, D. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Zhang, H. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Hansel, J. E. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Sharpe, J. P. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Johns, Russell C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2017-04-01
The RELAP-7 code is the next generation nuclear reactor system safety analysis code being developed at the Idaho National Laboratory (INL). The code is based on the INL’s modern scientific software development framework, MOOSE (Multi-Physics Object Oriented Simulation Environment). The overall design goal of RELAP-7 is to take advantage of the previous thirty years of advancements in computer architecture, software design, numerical integration methods, and physical models. The end result will be a reactor systems analysis capability that retains and improves upon RELAP5’s and TRACE’s capabilities and extends their analysis capabilities for all reactor system simulation scenarios. The RELAP-7 code utilizes the well-posed 7-equation two-phase flow model for compressible two-phase flow. Closure models used in the TRACE code has been reviewed and selected to reflect the progress made during the past decades and provide a basis for the colure correlations implemented in the RELAP-7 code. This document provides a summary on the closure correlations that are currently implemented in the RELAP-7 code. The closure correlations include sub-grid models that describe interactions between the fluids and the flow channel, and interactions between the two phases.
Variable angle correlation spectroscopy
International Nuclear Information System (INIS)
Lee, Y.K.; Lawrence Berkeley Lab., CA
1994-05-01
In this dissertation, a novel nuclear magnetic resonance (NMR) technique, variable angle correlation spectroscopy (VACSY) is described and demonstrated with 13 C nuclei in rapidly rotating samples. These experiments focus on one of the basic problems in solid state NMR: how to extract the wealth of information contained in the anisotropic component of the NMR signal while still maintaining spectral resolution. Analysis of the anisotropic spectral patterns from poly-crystalline systems reveal information concerning molecular structure and dynamics, yet in all but the simplest of systems, the overlap of spectral patterns from chemically distinct sites renders the spectral analysis difficult if not impossible. One solution to this problem is to perform multi-dimensional experiments where the high-resolution, isotropic spectrum in one dimension is correlated with the anisotropic spectral patterns in the other dimensions. The VACSY technique incorporates the angle between the spinner axis and the static magnetic field as an experimental parameter that may be incremented during the course of the experiment to help correlate the isotropic and anisotropic components of the spectrum. The two-dimensional version of the VACSY experiments is used to extract the chemical shift anisotropy tensor values from multi-site organic molecules, study molecular dynamics in the intermediate time regime, and to examine the ordering properties of partially oriented samples. The VACSY technique is then extended to three-dimensional experiments to study slow molecular reorientations in a multi-site polymer system
Neural Correlates of Gratitude
Directory of Open Access Journals (Sweden)
Glenn Ryan Fox
2015-09-01
Full Text Available Gratitude is an important aspect of human sociality, and is valued by religions and moral philosophies. It has been established that gratitude leads to benefits for both mental health and interpersonal relationships. It is thus important to elucidate the neurobiological correlates of gratitude, which are only now beginning to be investigated. To this end, we conducted an experiment during which we induced gratitude in participants while they underwent functional magnetic resonance imaging. We hypothesized that gratitude ratings would correlate with activity in brain regions associated with moral cognition, value judgment and theory of mind. The stimuli used to elicit gratitude were drawn from stories of survivors of the Holocaust, as many survivors report being sheltered by strangers or receiving lifesaving food and clothing, and having strong feelings of gratitude for such gifts. The participants were asked to place themselves in the context of the Holocaust and imagine what their own experience would feel like if they received such gifts. For each gift, they rated how grateful they felt. The results revealed that ratings of gratitude correlated with brain activity in the anterior cingulate cortex and medial prefrontal cortex, in support of our hypotheses. The results provide a window into the brain circuitry for moral cognition and positive emotion that accompanies the experience of benefitting from the goodwill of others.
Directory of Open Access Journals (Sweden)
Semir Zeki
Full Text Available In this work, we address an important but unexplored topic, namely the neural correlates of hate. In a block-design fMRI study, we scanned 17 normal human subjects while they viewed the face of a person they hated and also faces of acquaintances for whom they had neutral feelings. A hate score was obtained for the object of hate for each subject and this was used as a covariate in a between-subject random effects analysis. Viewing a hated face resulted in increased activity in the medial frontal gyrus, right putamen, bilaterally in premotor cortex, in the frontal pole and bilaterally in the medial insula. We also found three areas where activation correlated linearly with the declared level of hatred, the right insula, right premotor cortex and the right fronto-medial gyrus. One area of deactivation was found in the right superior frontal gyrus. The study thus shows that there is a unique pattern of activity in the brain in the context of hate. Though distinct from the pattern of activity that correlates with romantic love, this pattern nevertheless shares two areas with the latter, namely the putamen and the insula.
Neural correlates of gratitude.
Fox, Glenn R; Kaplan, Jonas; Damasio, Hanna; Damasio, Antonio
2015-01-01
Gratitude is an important aspect of human sociality, and is valued by religions and moral philosophies. It has been established that gratitude leads to benefits for both mental health and interpersonal relationships. It is thus important to elucidate the neurobiological correlates of gratitude, which are only now beginning to be investigated. To this end, we conducted an experiment during which we induced gratitude in participants while they underwent functional magnetic resonance imaging. We hypothesized that gratitude ratings would correlate with activity in brain regions associated with moral cognition, value judgment and theory of mind. The stimuli used to elicit gratitude were drawn from stories of survivors of the Holocaust, as many survivors report being sheltered by strangers or receiving lifesaving food and clothing, and having strong feelings of gratitude for such gifts. The participants were asked to place themselves in the context of the Holocaust and imagine what their own experience would feel like if they received such gifts. For each gift, they rated how grateful they felt. The results revealed that ratings of gratitude correlated with brain activity in the anterior cingulate cortex and medial prefrontal cortex, in support of our hypotheses. The results provide a window into the brain circuitry for moral cognition and positive emotion that accompanies the experience of benefitting from the goodwill of others.
Wavelet Correlation Coefficient of 'strongly correlated' financial time series
Razdan, Ashok
2003-01-01
In this paper we use wavelet concepts to show that correlation coefficient between two financial data's is not constant but varies with scale from high correlation value to strongly anti-correlation value This studies is important because correlation coefficient is used to quantify degree of independence between two variables. In econophysics correlation coefficient forms important input to evolve hierarchial tree and minimum spanning tree of financial data.
Biological Correlates of Empathy
Directory of Open Access Journals (Sweden)
E. Timucin Oral
2010-04-01
Full Text Available Empathy can be defined as the capacity to know emotionally what another is experiencing from within the frame of reference of that other person and the capacity to sample the feelings of another or it can be metaphorized as to put oneself in another’s shoes. Although the concept of empathy was firstly described in psychological theories, researches studying the biological correlates of psychological theories have been increasing recently. Not suprisingly, dinamically oriented psychotherapists Freud, Kohut, Basch and Fenichel had suggested theories about the biological correlates of empathy concept and established the basis of this modality decades ago. Some other theorists emphasized the importance of empathy in the early years of lifetime regarding mother-child attachment in terms of developmental psychology and investigated its role in explanation of psychopathology. The data coming from some of the recent brain imaging and animal model studies also seem to support these theories. Although increased activity in different brain regions was shown in many of the brain imaging studies, the role of cingulate cortex for understanding mother-child relationship was constantly emphasized in nearly all of the studies. In addition to these studies, a group of Italian scientists has defined a group of neurons as “mirror neurons” in their studies observing rhesus macaque monkeys. Later, they also defined mirror neurons in human studies, and suggested them as “empathy neurons”. After the discovery of mirror neurons, the hopes of finding the missing part of the puzzle for understanding the biological correlates of empathy raised again. Although the roles of different biological parameters such as skin conductance and pupil diameter for defining empathy have not been certain yet, they are going to give us the opportunity to revise the inconsistent basis of structural validity in psychiatry and to stabilize descriptive validity. In this review, the
The isotope correlation experiment
International Nuclear Information System (INIS)
Koch, L.; Schoof, S.
1983-01-01
The ESARDA working group on Isotopic Correlation Techniques, ICT and Reprocessing Input Analysis performed an Isotope Correlation Experiment, ICE with the aim to check the feasibility of the new technique. Ten input batches of the reprocessing of the KWO fuel at the WAK plant were analysed by 4 laboratories. All information to compare ICT with the gravimetric and volumetric methods was available. ICT combined with simplified reactor physics calculation was included. The main objectives of the statistical data evaluation were detection of outliers, the estimation of random errors and of systematic errors of the measurements performed by the 4 laboratories. Different methods for outlier detection, analysis of variances, Grubbs' analysis for the constant-bias model and Jaech's non-constant-bias model were applied. Some of the results of the statistical analysis may seem inconsistent which is due to the following reasons. For the statistical evaluations isotope abundance data (weight percent) as well as nuclear concentration data (atoms/initial metal atoms) were subjected to different outlier criteria before being used for further statistical evaluations. None of the four data evaluation groups performed a complete statistical data analysis which would render possible a comparison of the different methods applied since no commonly agreed statistical evaluation procedure existed. The results prove that ICT is as accurate as conventional techniques which have to rely on costly mass spectrometric isotope dilution analysis. The potential of outlier detection by ICT on the basis of the results from a single laboratory is as good as outlier detection by costly interlaboratory comparison. The application of fission product or Cm-244 correlations would be more timely than remeasurements at safeguards laboratories
Bootstrapped Deattenuated Correlation: Nonnormal Distributions
Padilla, Miguel A.; Veprinsky, Anna
2014-01-01
Correlation attenuation due to measurement error and a corresponding correction, the deattenuated correlation, have been known for over a century. Nevertheless, the deattenuated correlation remains underutilized. A few studies in recent years have investigated factors affecting the deattenuated correlation, and a couple of them provide alternative…
Strain induced adatom correlations
Kappus, Wolfgang
2012-12-01
A Born-Green-Yvon type model for adatom density correlations is combined with a model for adatom interactions mediated by the strain in elastic anisotropic substrates. The resulting nonlinear integral equation is solved numerically for coverages from zero to a limit given by stability constraints. W, Nb, Ta and Au surfaces are taken as examples to show the effects of different elastic anisotropy regions. Results of the calculation are shown by appropriate plots and discussed. A mapping to superstructures is tried. Corresponding adatom configurations from Monte Carlo simulations are shown.
Pairing correlations around scission
International Nuclear Information System (INIS)
Krappe, H.J.; Fadeev, S.
2001-01-01
To describe pairing correlations in a fissioning system one commonly projects the BCS wave function separately onto good particle numbers in each fragment in the exit channel, but only onto the total number of particles in the parent system. We propose to interpolate between these limiting situations by the generator-coordinate method with the particle-number difference between the nascent fragments as the generator coordinate. Model calculations are presented for the Hill-Wheeler-box potential with a δ-function diaphragm to mimic scission
Grayscale Optical Correlator Workbench
Hanan, Jay; Zhou, Hanying; Chao, Tien-Hsin
2006-01-01
Grayscale Optical Correlator Workbench (GOCWB) is a computer program for use in automatic target recognition (ATR). GOCWB performs ATR with an accurate simulation of a hardware grayscale optical correlator (GOC). This simulation is performed to test filters that are created in GOCWB. Thus, GOCWB can be used as a stand-alone ATR software tool or in combination with GOC hardware for building (target training), testing, and optimization of filters. The software is divided into three main parts, denoted filter, testing, and training. The training part is used for assembling training images as input to a filter. The filter part is used for combining training images into a filter and optimizing that filter. The testing part is used for testing new filters and for general simulation of GOC output. The current version of GOCWB relies on the mathematical software tools from MATLAB binaries for performing matrix operations and fast Fourier transforms. Optimization of filters is based on an algorithm, known as OT-MACH, in which variables specified by the user are parameterized and the best filter is selected on the basis of an average result for correct identification of targets in multiple test images.
Hexagonalization of correlation functions
Energy Technology Data Exchange (ETDEWEB)
Fleury, Thiago [Instituto de Física Teórica, UNESP - University Estadual Paulista,ICTP South American Institute for Fundamental Research,Rua Dr. Bento Teobaldo Ferraz 271, 01140-070, São Paulo, SP (Brazil); Komatsu, Shota [Perimeter Institute for Theoretical Physics,31 Caroline St N Waterloo, Ontario N2L 2Y5 (Canada)
2017-01-30
We propose a nonperturbative framework to study general correlation functions of single-trace operators in N=4 supersymmetric Yang-Mills theory at large N. The basic strategy is to decompose them into fundamental building blocks called the hexagon form factors, which were introduced earlier to study structure constants using integrability. The decomposition is akin to a triangulation of a Riemann surface, and we thus call it hexagonalization. We propose a set of rules to glue the hexagons together based on symmetry, which naturally incorporate the dependence on the conformal and the R-symmetry cross ratios. Our method is conceptually different from the conventional operator product expansion and automatically takes into account multi-trace operators exchanged in OPE channels. To illustrate the idea in simple set-ups, we compute four-point functions of BPS operators of arbitrary lengths and correlation functions of one Konishi operator and three short BPS operators, all at one loop. In all cases, the results are in perfect agreement with the perturbative data. We also suggest that our method can be a useful tool to study conformal integrals, and show it explicitly for the case of ladder integrals.
Cluster-cluster correlations and constraints on the correlation hierarchy
Hamilton, A. J. S.; Gott, J. R., III
1988-01-01
The hypothesis that galaxies cluster around clusters at least as strongly as they cluster around galaxies imposes constraints on the hierarchy of correlation amplitudes in hierachical clustering models. The distributions which saturate these constraints are the Rayleigh-Levy random walk fractals proposed by Mandelbrot; for these fractal distributions cluster-cluster correlations are all identically equal to galaxy-galaxy correlations. If correlation amplitudes exceed the constraints, as is observed, then cluster-cluster correlations must exceed galaxy-galaxy correlations, as is observed.
Qian, Weixian; Zhou, Xiaojun; Lu, Yingcheng; Xu, Jiang
2015-09-15
Both the Jones and Mueller matrices encounter difficulties when physically modeling mixed materials or rough surfaces due to the complexity of light-matter interactions. To address these issues, we derived a matrix called the paths correlation matrix (PCM), which is a probabilistic mixture of Jones matrices of every light propagation path. Because PCM is related to actual light propagation paths, it is well suited for physical modeling. Experiments were performed, and the reflection PCM of a mixture of polypropylene and graphite was measured. The PCM of the mixed sample was accurately decomposed into pure polypropylene's single reflection, pure graphite's single reflection, and depolarization caused by multiple reflections, which is consistent with the theoretical derivation. Reflection parameters of rough surface can be calculated from PCM decomposition, and the results fit well with the theoretical calculations provided by the Fresnel equations. These theoretical and experimental analyses verify that PCM is an efficient way to physically model light-matter interactions.
Correlates of physical activity
DEFF Research Database (Denmark)
Bauman, Adrian E; Reis, Rodrigo S; Sallis, James F
2012-01-01
that age, sex, health status, self-efficacy, and motivation are associated with physical activity. Ecological models take a broad view of health behaviour causation, with the social and physical environment included as contributors to physical inactivity, particularly those outside the health sector...... effective programmes will target factors known to cause inactivity. Research into correlates (factors associated with activity) or determinants (those with a causal relationship) has burgeoned in the past two decades, but has mostly focused on individual-level factors in high-income countries. It has shown......, such as urban planning, transportation systems, and parks and trails. New areas of determinants research have identified genetic factors contributing to the propensity to be physically active, and evolutionary factors and obesity that might predispose to inactivity, and have explored the longitudinal tracking...
Packing force data correlations
International Nuclear Information System (INIS)
Heiman, S.M.
1994-01-01
One of the issues facing valve maintenance personnel today deals with an appropriate methodology for installing and setting valve packing that will minimize leak rates, yet ensure functionality of the the valve under all anticipated operating conditions. Several variables can affect a valve packing's ability to seal, such as packing bolt torque, stem finish, and lubrication. Stem frictional force can be an excellent overall indicator of some of the underlying conditions that affect the sealing characteristics of the packing and the best parameter to use when adjusting the packing. This paper addresses stem friction forces, analytically derives the equations related to these forces, presents a methodology for measuring these forces on valve stems, and attempts to correlate the data directly to the underlying variables
International Nuclear Information System (INIS)
Corwin, W.R.
1995-01-01
This task has been established with the explicit purpose of ensuring the continued availability of the pedigreed and extremely well-characterized material now required for inclusion in all additional and future surveillance capsules in commercial light-water reactors. During this reporting period, concrete was poured and pallets storage racks were installed to provide adequate room for the storage of the correlation monitor material being transferred from its location at the Y-12 Plant to its archival storage location at ORNL. The racks came from surplus material storage at ORNL and hence were obtained at no cost to the HSSI Program. Inquiries into cost-effective means of sheltering the blocks of correlation monitor materials from further weather-related deteriorization were initiated. The most likely approach would be to procure a turn-key sheet metal building installed over the storage racks by an outside contractor to minimize costs. Most of the material has now been transferred from Y-12 to the ORNL storage area. It has been repositioned on new storage pallets and placed into the storage racks, An update of the detailed material inventory was initiated to ascertain the revised location of all blocks. Pieces of HSST plate O3 were distributed to participants in the ASTM cross-comparison exercise on subsize specimen testing technology. The use of the HSST O3 will provide for data from the many varieties of tests to be performed to be compared with the standardized data previously developed. The testing techniques will focus on ways to measure transition temperature and fracture toughness
Clinicopathological correlates of hyperparathyroidism.
Duan, Kai; Gomez Hernandez, Karen; Mete, Ozgur
2015-10-01
Hyperparathyroidism is a common endocrine disorder with potential complications on the skeletal, renal, neurocognitive and cardiovascular systems. While most cases (95%) occur sporadically, about 5% are associated with a hereditary syndrome: multiple endocrine neoplasia syndromes (MEN-1, MEN-2A, MEN-4), hyperparathyroidism-jaw tumour syndrome (HPT-JT), familial hypocalciuric hypercalcaemia (FHH-1, FHH-2, FHH-3), familial hypercalciuric hypercalcaemia, neonatal severe hyperparathyroidism and isolated familial hyperparathyroidism. Recently, molecular mechanisms underlying possible tumour suppressor genes (MEN1, CDC73/HRPT2, CDKIs, APC, SFRPs, GSK3β, RASSF1A, HIC1, RIZ1, WT1, CaSR, GNA11, AP2S1) and proto-oncogenes (CCND1/PRAD1, RET, ZFX, CTNNB1, EZH2) have been uncovered in the pathogenesis of hyperparathyroidism. While bi-allelic inactivation of CDC73/HRPT2 seems unique to parathyroid malignancy, aberrant activation of cyclin D1 and Wnt/β-catenin signalling has been reported in benign and malignant parathyroid tumours. Clinicopathological correlates of primary hyperparathyroidism include parathyroid adenoma (80-85%), hyperplasia (10-15%) and carcinoma (hyperparathyroidism generally presents with diffuse parathyroid hyperplasia, whereas tertiary hyperparathyroidism reflects the emergence of autonomous parathyroid hormone (PTH)-producing neoplasm(s) from secondary parathyroid hyperplasia. Surgical resection of abnormal parathyroid tissue remains the only curative treatment in primary hyperparathyroidism, and parathyroidectomy specimens are frequently encountered in this setting. Clinical and biochemical features, including intraoperative PTH levels, number, weight and size of the affected parathyroid gland(s), are crucial parameters to consider when rendering an accurate diagnosis of parathyroid proliferations. This review provides an update on the expanding knowledge of hyperparathyroidism and highlights the clinicopathological correlations of this prevalent
Protecting Quantum Correlation from Correlated Amplitude Damping Channel
Huang, Zhiming; Zhang, Cai
2017-08-01
In this work, we investigate the dynamics of quantum correlation measured by measurement-induced nonlocality (MIN) and local quantum uncertainty (LQU) in correlated amplitude damping (CAD) channel. We find that the memory parameter brings different influences on MIN and LQU. In addition, we propose a scheme to protect quantum correlation by executing prior weak measurement (WM) and post-measurement reversal (MR). However, better protection of quantum correlation by the scheme implies a lower success probability (SP).
Curme, Chester
Technological advances have provided scientists with large high-dimensional datasets that describe the behaviors of complex systems: from the statistics of energy levels in complex quantum systems, to the time-dependent transcription of genes, to price fluctuations among assets in a financial market. In this environment, where it may be difficult to infer the joint distribution of the data, network science has flourished as a way to gain insight into the structure and organization of such systems by focusing on pairwise interactions. This work focuses on a particular setting, in which a system is described by multivariate time series data. We consider time-lagged correlations among elements in this system, in such a way that the measured interactions among elements are asymmetric. Finally, we allow these interactions to be characteristically weak, so that statistical uncertainties may be important to consider when inferring the structure of the system. We introduce a methodology for constructing statistically validated networks to describe such a system, extend the methodology to accommodate interactions with a periodic component, and show how consideration of bipartite community structures in these networks can aid in the construction of robust statistical models. An example of such a system is a financial market, in which high frequency returns data may be used to describe contagion, or the spreading of shocks in price among assets. These data provide the experimental testing ground for our methodology. We study NYSE data from both the present day and one decade ago, examine the time scales over which the validated lagged correlation networks exist, and relate differences in the topological properties of the networks to an increasing economic efficiency. We uncover daily periodicities in the validated interactions, and relate our findings to explanations of the Epps Effect, an empirical phenomenon of financial time series. We also study bipartite community
Standard Errors for Matrix Correlations.
Ogasawara, Haruhiko
1999-01-01
Derives the asymptotic standard errors and intercorrelations for several matrix correlations assuming multivariate normality for manifest variables and derives the asymptotic standard errors of the matrix correlations for two factor-loading matrices. (SLD)
On the Kendall Correlation Coefficient
Stepanov, Alexei
2015-01-01
In the present paper, we first discuss the Kendall rank correlation coefficient. In continuous case, we define the Kendall rank correlation coefficient in terms of the concomitants of order statistics, find the expected value of the Kendall rank correlation coefficient and show that the later is free of n. We also prove that in continuous case the Kendall correlation coefficient converges in probability to its expected value. We then propose to consider the expected value of the Kendall rank ...
Maguire, Charles Felix
2012-01-01
The measurements of the anisotropic flow of single particles and particle pairs have provided some of the most compelling evidence for the creation of a strongly interacting quark-gluon plasma (sQGP) in relativistic heavy ion collisions, first at RHIC, and more recently at the LHC. Using PbPb collision data taken in the 2010 and 2011 heavy ion runs at the LHC, the CMS experiment has investigated a broad scope of these flow phenomena. The $v_2$ elliptic flow coefficient has been extracted with four different methods to cross-check contributions from initial state fluctuations and non-flow correlations. The measurements of the $v_2$ elliptic anisotropy have been extended to a transverse momentum of 60 GeV/c, which will enable the placement of new quantitative constraints on parton energy loss models as a function of path length in the sQGP medium. Additionally, for the first time at the LHC, the CMS experiment has extracted precise elliptic anisotropy coefficients for the neutral $\\pi$ meson ($\\pi^0$) in the c...
Relativistic correlations in atoms
International Nuclear Information System (INIS)
Dietz, K.
1987-01-01
Atoms are particularly well-suited objects when it comes to testing certain concepts of many-body theories. They play a unique role in this respect because of two constructively interfering reasons: first of all, the laws describing the interactions of their constituents are the ones best known in all of Physics; secondly, their structure is comparatively simple and amenable to concise theoretical treatment. Because of these two reasons, physically motivated many-body approximation schemes, ordered in a systematic hierarchy of precision, can be carefully tested; discrepancies between theory and experiment are due to many-body effects and are never masked by uncertainties in the constituent-interaction (needless to say, the very small hadronic contributions to atomic structure is left out. Many-body effects in atoms are solely produced by the electron-electron interaction which derives from the laws of Quantum Electrodynamics or, in a very good approximation from the repulsive Coulomb potential; in the general nomenclature they are named correlations. The material is organized in two chapters: chapter 1 deals with a general introduction and discussion of g-Hartree mean-field theories, chapter 2 deals with applications. The role of vacuum fluctuations and deformations of the Dirac sea in a consistent construction of mean-fields is emphasized and their explicit form in the g-Hartree theory is given. 21 references, 5 figures, 3 tables
Yuksel, Kivanc; Chang, Xin; Skarbek, Władysław
2017-08-01
The novel smile recognition algorithm is presented based on extraction of 68 facial salient points (fp68) using the ensemble of regression trees. The smile detector exploits the Support Vector Machine linear model. It is trained with few hundreds exemplar images by SVM algorithm working in 136 dimensional space. It is shown by the strict statistical data analysis that such geometric detector strongly depends on the geometry of mouth opening area, measured by triangulation of outer lip contour. To this goal two Bayesian detectors were developed and compared with SVM detector. The first uses the mouth area in 2D image, while the second refers to the mouth area in 3D animated face model. The 3D modeling is based on Candide-3 model and it is performed in real time along with three smile detectors and statistics estimators. The mouth area/Bayesian detectors exhibit high correlation with fp68/SVM detector in a range [0:8; 1:0], depending mainly on light conditions and individual features with advantage of 3D technique, especially in hard light conditions.
Correlates of Sensitive Technologies
Energy Technology Data Exchange (ETDEWEB)
Nelson, Paul [Texas A & M Univ., College Station, TX (United States)
2016-04-22
By “Quantitative Empirical Analysis” (QEA) is intended the use of statistical methods to infer, from data that often tend to be of a historical nature, the characteristics of states that correlate with some designated dependent variable (e.g. proliferation of nuclear weapons). QEA is a well-established approach in the social sciences, but is not notably well-known among physical scientists, who tend to think of the social sciences as inherently qualitative. This article attempts to provide a snapshot of research, most of which has evolved over the past decade, involving the application of QEA to issues in which the dependent variable of interest is intended as some measure of nuclear proliferation. Standard practices in QEA are described, especially as they relate to data collection. The QEA approach is compared and contrasted to other quantitative approaches to studying proliferation-related issues, including a “figure of merit” approach that has largely been developed within the DOE complex, and two distinct methodologies termed in a recent US National Academy of Sciences study as “case by case” and “predefined framework.” Sample results from QEA applied to proliferation are indicated, as are doubts about such quantitative approaches. A simplistic decision-theoretic model of the optimal time for the international community to intervene in a possible proliferation scenario is used to illustrate the possibility of synergies between different approaches
Correlates of Sensitive Technologies
International Nuclear Information System (INIS)
Nelson, Paul
2016-01-01
By 'Quantitative Empirical Analysis' (QEA) is intended the use of statistical methods to infer, from data that often tend to be of a historical nature, the characteristics of states that correlate with some designated dependent variable (e.g. proliferation of nuclear weapons). QEA is a well-established approach in the social sciences, but is not notably well-known among physical scientists, who tend to think of the social sciences as inherently qualitative. This article attempts to provide a snapshot of research, most of which has evolved over the past decade, involving the application of QEA to issues in which the dependent variable of interest is intended as some measure of nuclear proliferation. Standard practices in QEA are described, especially as they relate to data collection. The QEA approach is compared and contrasted to other quantitative approaches to studying proliferation-related issues, including a 'figure of merit' approach that has largely been developed within the DOE complex, and two distinct methodologies termed in a recent US National Academy of Sciences study as 'case by case' and 'predefined framework.' Sample results from QEA applied to proliferation are indicated, as are doubts about such quantitative approaches. A simplistic decision-theoretic model of the optimal time for the international community to intervene in a possible proliferation scenario is used to illustrate the possibility of synergies between different approaches
Correlations in the Grover search
International Nuclear Information System (INIS)
Cui Jian; Fan Heng
2010-01-01
The Grover search is a well-known quantum algorithm that outperforms any classical search algorithm. It is known that quantum correlations such as entanglement are responsible for the power of some quantum information protocols. But entanglement is not the only kind of quantum correlations. Other quantum correlations such as quantum discord are also useful to capture some important properties of the nonclassical correlation. Also there is no well-accepted and clear distinction between quantum correlations and classical correlations. In this paper, we systematically investigate several kinds of correlations including both quantum and classical in the whole process of the Grover search algorithm. These correlations are the concurrence, entanglement of formation, quantum discord, classical correlation and mutual information. The behaviors of quantum discord, classical correlation and mutual information are almost the same while the concurrence is different in the qubit-qubit case. For the qubit partition 1: n case, the behaviors of all correlations are qualitative the same. When the search is over, all kinds of correlations are zero, we argue that this is necessary for the final step in the search.
Professional correlates of insomnia.
Léger, Damien; Massuel, Marie-Anne; Metlaine, Arnaud
2006-02-01
Insomnia is a highly prevalent disorder that affects daytime functioning, behavior, and quality of life. Several reports have shown that insomnia impacts on the workforce and is associated with an increased risk of absenteeism. However, few workplace studies have been performed. Our study attempted to evaluate the professional correlates of insomnia by comparing a group of workers with insomnia to a matched group of good sleepers. The main objective measure was absenteeism. Accidents, self-esteem at work, job satisfaction, and efficiency at work were also investigated. Pairs of workers with insomnia (according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition definition) and good sleepers, matched by age, sex, and occupational status, were interviewed by their occupational physician and also answered a self-administered questionnaire on work-related criteria. Objective data on absenteeism (number of days absent from work) were provided by the employers' health resource databases. Paris and the Ile de France region (France). Seven hundred eighty-five subjects completed the questionnaire. We retained 369 pair (ie, 738 subjects) for analysis. Insomniacs missed work twice as often as good sleepers. The difference between insomniacs and good sleepers in terms of absenteeism was particularly high for blue-collar workers (odds ratio = 3.0) and men (odds ratio = 2.31). Insomniacs had also a higher accident rate while driving and, strikingly, a 3-fold greater risk of having 2 or 3 serious road accidents. They also reported poor self-esteem at work, less job satisfaction, and less efficiency at work, compared with good sleepers. Our study found an objective increase in absenteeism in insomniacs compared with good sleepers.
A unitary correlation operator method
International Nuclear Information System (INIS)
Feldmeier, H.; Neff, T.; Roth, R.; Schnack, J.
1997-09-01
The short range repulsion between nucleons is treated by a unitary correlation operator which shifts the nucleons away from each other whenever their uncorrelated positions are within the repulsive core. By formulating the correlation as a transformation of the relative distance between particle pairs, general analytic expressions for the correlated wave functions and correlated operators are given. The decomposition of correlated operators into irreducible n-body operators is discussed. The one- and two-body-irreducible parts are worked out explicitly and the contribution of three-body correlations is estimated to check convergence. Ground state energies of nuclei up to mass number A=48 are calculated with a spin-isospin-dependent potential and single Slater determinants as uncorrelated states. They show that the deduced energy-and mass-number-independent correlated two-body Hamiltonian reproduces all ''exact'' many-body calculations surprisingly well. (orig.)
Correlation Structures of Correlated Binomial Models and Implied Default Distribution
S. Mori; K. Kitsukawa; M. Hisakado
2006-01-01
We show how to analyze and interpret the correlation structures, the conditional expectation values and correlation coefficients of exchangeable Bernoulli random variables. We study implied default distributions for the iTraxx-CJ tranches and some popular probabilistic models, including the Gaussian copula model, Beta binomial distribution model and long-range Ising model. We interpret the differences in their profiles in terms of the correlation structures. The implied default distribution h...
Correlation Structures of Correlated Binomial Models and Implied Default Distribution
Mori, Shintaro; Kitsukawa, Kenji; Hisakado, Masato
2008-11-01
We show how to analyze and interpret the correlation structures, the conditional expectation values and correlation coefficients of exchangeable Bernoulli random variables. We study implied default distributions for the iTraxx-CJ tranches and some popular probabilistic models, including the Gaussian copula model, Beta binomial distribution model and long-range Ising model. We interpret the differences in their profiles in terms of the correlation structures. The implied default distribution has singular correlation structures, reflecting the credit market implications. We point out two possible origins of the singular behavior.
From micro-correlations to macro-correlations
International Nuclear Information System (INIS)
Eliazar, Iddo
2016-01-01
Random vectors with a symmetric correlation structure share a common value of pair-wise correlation between their different components. The symmetric correlation structure appears in a multitude of settings, e.g. mixture models. In a mixture model the components of the random vector are drawn independently from a general probability distribution that is determined by an underlying parameter, and the parameter itself is randomized. In this paper we study the overall correlation of high-dimensional random vectors with a symmetric correlation structure. Considering such a random vector, and terming its pair-wise correlation “micro-correlation”, we use an asymptotic analysis to derive the random vector’s “macro-correlation” : a score that takes values in the unit interval, and that quantifies the random vector’s overall correlation. The method of obtaining macro-correlations from micro-correlations is then applied to a diverse collection of frameworks that demonstrate the method’s wide applicability.
Electronic Correlation Strength of Pu
DEFF Research Database (Denmark)
Svane, A.; C. Albers, R.; E. Christensen, N.
2013-01-01
A new electronic quantity, the correlation strength, is defined as a necessary step for understanding the properties and trends in strongly correlated electronic materials. As a test case, this is applied to the different phases of elemental Pu. Within the GW approximation we have surprisingly...... found a "universal" scaling relationship, where the f-electron bandwidth reduction due to correlation effects is shown to depend only upon the local density approximation (LDA) bandwidth and is otherwise independent of crystal structure and lattice constant....
Intermittency analysis of correlated data
International Nuclear Information System (INIS)
Wosiek, B.
1992-01-01
We describe the method of the analysis of the dependence of the factorial moments on the bin size in which the correlations between the moments computed for different bin sizes are taken into account. For large multiplicity nucleus-nucleus data inclusion of the correlations does not change the values of the slope parameter, but gives errors significantly reduced as compared to the case of fits with no correlations. (author)
Correlated electrons and generalized statistics
International Nuclear Information System (INIS)
Wang, Q.A.
2003-01-01
Several important generalizations of Fermi-Dirac distribution are compared to numerical and experimental results for correlated electron systems. It is found that the quantum distributions based on incomplete information hypothesis can be useful for describing this kind of systems. We show that the additive incomplete fermion distribution gives very good description of weakly correlated electrons and that the non-additive one is suitable to very strong correlated cases. (author)
Multiview Bayesian Correlated Component Analysis
DEFF Research Database (Denmark)
Kamronn, Simon Due; Poulsen, Andreas Trier; Hansen, Lars Kai
2015-01-01
are identical. Here we propose a hierarchical probabilistic model that can infer the level of universality in such multiview data, from completely unrelated representations, corresponding to canonical correlation analysis, to identical representations as in correlated component analysis. This new model, which...... we denote Bayesian correlated component analysis, evaluates favorably against three relevant algorithms in simulated data. A well-established benchmark EEG data set is used to further validate the new model and infer the variability of spatial representations across multiple subjects....
A default Bayesian hypothesis test for correlations and partial correlations
Wetzels, R.; Wagenmakers, E.J.
2012-01-01
We propose a default Bayesian hypothesis test for the presence of a correlation or a partial correlation. The test is a direct application of Bayesian techniques for variable selection in regression models. The test is easy to apply and yields practical advantages that the standard frequentist tests
Mechanical shape correlation : a novel integrated digital image correlation approach
Kleinendorst, S.M.; Hoefnagels, J.P.M.; Geers, M.G.D.; Lamberti, L.; Lin, M.-T.; Furlong, C.; Sciammarella, C.
2018-01-01
Mechanical Shape Correlation (MSC) is a novel integrated digital image correlation technique, used to determine the optimal set of constitutive parameters to describe the experimentally observed mechanical behavior of a test specimen, based on digital images taken during the experiment. In contrast
Closed sets of nonlocal correlations
International Nuclear Information System (INIS)
Allcock, Jonathan; Linden, Noah; Brunner, Nicolas; Popescu, Sandu; Skrzypczyk, Paul; Vertesi, Tamas
2009-01-01
We present a fundamental concept - closed sets of correlations - for studying nonlocal correlations. We argue that sets of correlations corresponding to information-theoretic principles, or more generally to consistent physical theories, must be closed under a natural set of operations. Hence, studying the closure of sets of correlations gives insight into which information-theoretic principles are genuinely different, and which are ultimately equivalent. This concept also has implications for understanding why quantum nonlocality is limited, and for finding constraints on physical theories beyond quantum mechanics.
Correlation measurement of squeezed light
DEFF Research Database (Denmark)
Krivitsky, Leonid; Andersen, Ulrik Lund; Dong, R.
2009-01-01
We study the implementation of a correlation measurement technique for the characterization of squeezed light which is nearly free of electronic noise. With two different sources of squeezed light, we show that the sign of the covariance coefficient, revealed from the time-resolved correlation data......, is witnessing the presence of squeezing in the system. Furthermore, we estimate the degree of squeezing using the correlation method and compare it to the standard homodyne measurement scheme. We show that the role of electronic detector noise is minimized using the correlation approach as opposed to homodyning...
EPR correlations and EPW distributions
International Nuclear Information System (INIS)
Bell, J.S.
1995-01-01
In the case of two free spin-zero particles, the wave function originally considered by Einstein, Podolsky and Rosen to exemplify EPR correlations has a non-negative Wigner distribution. This distribution gives an explicitly local account of the correlations. For an irreducible non-locality, more elaborate wave functions are required, with Wigner distributions which are not non-negative. (author)
Some techniques of correlation experiments
International Nuclear Information System (INIS)
Allas, R.G.
1976-01-01
Some general remarks concerning correlation techniques are made. Most of the remarks are limited to correlated pairs of charged particles. The relatively simple system 3 He + 3 H → A + B + C, where all possible charged particle pairs A,B are detected and particle C is left undetected either charged or neutral, is considered. (G.T.H.)
Software Correlator for Radioastron Mission
Likhachev, Sergey F.; Kostenko, Vladimir I.; Girin, Igor A.; Andrianov, Andrey S.; Rudnitskiy, Alexey G.; Zharov, Vladimir E.
In this paper, we discuss the characteristics and operation of Astro Space Center (ASC) software FX correlator that is an important component of space-ground interferometer for Radioastron project. This project performs joint observations of compact radio sources using 10m space radio telescope (SRT) together with ground radio telescopes at 92, 18, 6 and 1.3 cm wavelengths. In this paper, we describe the main features of space-ground VLBI data processing of Radioastron project using ASC correlator. Quality of implemented fringe search procedure provides positive results without significant losses in correlated amplitude. ASC Correlator has a computational power close to real time operation. The correlator has a number of processing modes: “Continuum”, “Spectral Line”, “Pulsars”, “Giant Pulses”,“Coherent”. Special attention is paid to peculiarities of Radioastron space-ground VLBI data processing. The algorithms of time delay and delay rate calculation are also discussed, which is a matter of principle for data correlation of space-ground interferometers. During five years of Radioastron SRT successful operation, ASC correlator showed high potential of satisfying steady growing needs of current and future ground and space VLBI science. Results of ASC software correlator operation are demonstrated.
Heteronuclear Long-Range Correlation
DEFF Research Database (Denmark)
Sørensen, Ole W.
The lecture will cover heteronuclear long-range correlation techniques like HMBC, H2BC, and HAT HMBC with the emphasis on determining the number of covalent bonds between two spins being correlated. H2BC and HMBC spectra are quite complementary as a peak can be strong in one of the two spectra...
Correlations and Correlated Responses in Upland Cotton (Gossypium hirsutum L.
Directory of Open Access Journals (Sweden)
Echekwu, CA.
2001-01-01
Full Text Available Plant breeders must be concerned with the total array of economic characters in their efforts to develop a crop variety acceptable to farmers. Their selection endeavours must therefore take into consideration how changes in one trait affect, simultaneously changes in other economic attributes. The importance of correlations and correlated responses is therefore self evident in plant breeding endeavours. In this study F3 progenies from a cross between two cotton lines SAMCOT-9 x Y422 were evaluated for two years and performance data were used to obtain correlations between nine agronomic and fibre quality traits in upland cotton. The results indicated that plant helght was significantly and positively correlated with seed cotton yield, number of sympodial and monopodial branches, seed index, fibre length and micronaire index. Positive and significant correlations were also obtained between : seed cotton yield, tint percent and fibre strength and fibre length. Significant negative correlations were obtained between : plant height and lint percent ; number of monopodial branches, sympodial branches and lint percent ; fibre length, fibre strength and micronaire index. The correlated responses in the other eight traits when selection was practiced for seed cotton yield in the present study shows that it might be more profitable to practice direct selection for seed cotton yield compared to selecting for seed cotton yield through any of the other traits.
Correlation Functions and Power Spectra
DEFF Research Database (Denmark)
Larsen, Jan
2006-01-01
The present lecture note is a supplement to the textbook Digital Signal Processing by J. Proakis and D.G. Manolakis used in the IMM/DTU course 02451 Digital Signal Processing and provides an extended discussion of correlation functions and power spectra. The definitions of correlation functions...... and spectra for discrete-time and continuous-time (analog) signals are pretty similar. Consequently, we confine the discussion mainly to real discrete-time signals. The Appendix contains detailed definitions and properties of correlation functions and spectra for analog as well as discrete-time signals....... It is possible to define correlation functions and associated spectra for aperiodic, periodic and random signals although the interpretation is different. Moreover, we will discuss correlation functions when mixing these basic signal types. In addition, the note include several examples for the purpose...
Cross-correlation of long-range correlated series
International Nuclear Information System (INIS)
Arianos, Sergio; Carbone, Anna
2009-01-01
A method for estimating the cross-correlation C xy (τ) of long-range correlated series x(t) and y(t), at varying lags τ and scales n, is proposed. For fractional Brownian motions with Hurst exponents H 1 and H 2 , the asymptotic expression for C xy (τ) depends only on the lag τ (wide-sense stationarity) and scales as a power of n with exponent H 1 +H 2 for τ→0. The method is illustrated on: (i) financial series, to show the leverage effect; (ii) genomic sequences, to estimate the correlations between structural parameters along the chromosomes
Clustering Coefficients for Correlation Networks.
Masuda, Naoki; Sakaki, Michiko; Ezaki, Takahiro; Watanabe, Takamitsu
2018-01-01
Graph theory is a useful tool for deciphering structural and functional networks of the brain on various spatial and temporal scales. The clustering coefficient quantifies the abundance of connected triangles in a network and is a major descriptive statistics of networks. For example, it finds an application in the assessment of small-worldness of brain networks, which is affected by attentional and cognitive conditions, age, psychiatric disorders and so forth. However, it remains unclear how the clustering coefficient should be measured in a correlation-based network, which is among major representations of brain networks. In the present article, we propose clustering coefficients tailored to correlation matrices. The key idea is to use three-way partial correlation or partial mutual information to measure the strength of the association between the two neighboring nodes of a focal node relative to the amount of pseudo-correlation expected from indirect paths between the nodes. Our method avoids the difficulties of previous applications of clustering coefficient (and other) measures in defining correlational networks, i.e., thresholding on the correlation value, discarding of negative correlation values, the pseudo-correlation problem and full partial correlation matrices whose estimation is computationally difficult. For proof of concept, we apply the proposed clustering coefficient measures to functional magnetic resonance imaging data obtained from healthy participants of various ages and compare them with conventional clustering coefficients. We show that the clustering coefficients decline with the age. The proposed clustering coefficients are more strongly correlated with age than the conventional ones are. We also show that the local variants of the proposed clustering coefficients (i.e., abundance of triangles around a focal node) are useful in characterizing individual nodes. In contrast, the conventional local clustering coefficients were strongly
Clustering Coefficients for Correlation Networks
Directory of Open Access Journals (Sweden)
Naoki Masuda
2018-03-01
Full Text Available Graph theory is a useful tool for deciphering structural and functional networks of the brain on various spatial and temporal scales. The clustering coefficient quantifies the abundance of connected triangles in a network and is a major descriptive statistics of networks. For example, it finds an application in the assessment of small-worldness of brain networks, which is affected by attentional and cognitive conditions, age, psychiatric disorders and so forth. However, it remains unclear how the clustering coefficient should be measured in a correlation-based network, which is among major representations of brain networks. In the present article, we propose clustering coefficients tailored to correlation matrices. The key idea is to use three-way partial correlation or partial mutual information to measure the strength of the association between the two neighboring nodes of a focal node relative to the amount of pseudo-correlation expected from indirect paths between the nodes. Our method avoids the difficulties of previous applications of clustering coefficient (and other measures in defining correlational networks, i.e., thresholding on the correlation value, discarding of negative correlation values, the pseudo-correlation problem and full partial correlation matrices whose estimation is computationally difficult. For proof of concept, we apply the proposed clustering coefficient measures to functional magnetic resonance imaging data obtained from healthy participants of various ages and compare them with conventional clustering coefficients. We show that the clustering coefficients decline with the age. The proposed clustering coefficients are more strongly correlated with age than the conventional ones are. We also show that the local variants of the proposed clustering coefficients (i.e., abundance of triangles around a focal node are useful in characterizing individual nodes. In contrast, the conventional local clustering coefficients
Clustering Coefficients for Correlation Networks
Masuda, Naoki; Sakaki, Michiko; Ezaki, Takahiro; Watanabe, Takamitsu
2018-01-01
Graph theory is a useful tool for deciphering structural and functional networks of the brain on various spatial and temporal scales. The clustering coefficient quantifies the abundance of connected triangles in a network and is a major descriptive statistics of networks. For example, it finds an application in the assessment of small-worldness of brain networks, which is affected by attentional and cognitive conditions, age, psychiatric disorders and so forth. However, it remains unclear how the clustering coefficient should be measured in a correlation-based network, which is among major representations of brain networks. In the present article, we propose clustering coefficients tailored to correlation matrices. The key idea is to use three-way partial correlation or partial mutual information to measure the strength of the association between the two neighboring nodes of a focal node relative to the amount of pseudo-correlation expected from indirect paths between the nodes. Our method avoids the difficulties of previous applications of clustering coefficient (and other) measures in defining correlational networks, i.e., thresholding on the correlation value, discarding of negative correlation values, the pseudo-correlation problem and full partial correlation matrices whose estimation is computationally difficult. For proof of concept, we apply the proposed clustering coefficient measures to functional magnetic resonance imaging data obtained from healthy participants of various ages and compare them with conventional clustering coefficients. We show that the clustering coefficients decline with the age. The proposed clustering coefficients are more strongly correlated with age than the conventional ones are. We also show that the local variants of the proposed clustering coefficients (i.e., abundance of triangles around a focal node) are useful in characterizing individual nodes. In contrast, the conventional local clustering coefficients were strongly
Directory of Open Access Journals (Sweden)
Takashi Yanagisawa
2015-01-01
Full Text Available We investigate the ground state of two-dimensional Hubbard model on the basis of the variational Monte Carlo method. We use wave functions that include kinetic correlation and doublon-holon correlation beyond the Gutzwiller ansatz. It is still not clear whether the Hubbard model accounts for high-temperature superconductivity. The antiferromagnetic correlation plays a key role in the study of pairing mechanism because the superconductive phase exists usually close to the antiferromagnetic phase. We investigate the stability of the antiferromagnetic state when holes are doped as a function of the Coulomb repulsion U. We show that the antiferromagnetic correlation is suppressed as U is increased exceeding the bandwidth. High-temperature superconductivity is possible in this region with enhanced antiferromagnetic spin fluctuation and pairing interaction.
25 ns software correlator for photon and fluorescence correlation spectroscopy
Magatti, Davide; Ferri, Fabio
2003-02-01
A 25 ns time resolution, multi-tau software correlator developed in LABVIEW based on the use of a standard photon counting unit, a fast timer/counter board (6602-PCI National Instrument) and a personal computer (PC) (1.5 GHz Pentium 4) is presented and quantitatively discussed. The correlator works by processing the stream of incoming data in parallel according to two different algorithms: For large lag times (τ⩾100 μs), a classical time-mode (TM) scheme, based on the measure of the number of pulses per time interval, is used; differently, for τ⩽100 μs a photon-mode (PM) scheme is adopted and the time sequence of the arrival times of the photon pulses is measured. By combining the two methods, we developed a system capable of working out correlation functions on line, in full real time for the TM correlator and partially in batch processing for the PM correlator. For the latter one, the duty cycle depends on the count rate of the incoming pulses, being ˜100% for count rates ⩽3×104 Hz, ˜15% at 105 Hz, and ˜1% at 106 Hz. For limitations imposed by the fairly small first-in, first-out (FIFO) buffer available on the counter board, the maximum count rate permissible for a proper functioning of the PM correlator is limited to ˜105 Hz. However, this limit can be removed by using a board with a deeper FIFO. Similarly, the 25 ns time resolution is only limited by maximum clock frequency available on the 6602-PCI and can be easily improved by using a faster clock. When tested on dilute solutions of calibrated latex spheres, the overall performances of the correlator appear to be comparable with those of commercial hardware correlators, but with several nontrivial advantages related to its flexibility, low cost, and easy adaptability to future developments of PC and data acquisition technology.
International Nuclear Information System (INIS)
Kiltie, A.E.; Ryan, A.J.; Swindell, R.; Barber, J.B.P.; West, C.M.L.; Magee, B.; Hendry, J.H.
1999-01-01
Background and purpose: Prediction of late normal tissue reactions to radiotherapy would permit tailoring of dosage to each patient. Measurement of residual DNA double strand breaks using pulsed field gel electrophoresis (PFGE) shows promise in this field. The aim of this study was to test the predictive potential of PFGE in a group of retrospectively studied breast cancer patients.Materials and methods: Thirty nine patients, treated uniformly for breast cancer 9-15 years previously, with excision of the tumour and radiotherapy to the breast and drainage areas, were assessed clinically using the LENT SOMA scale, and a 5-mm punch biopsy taken from the buttock. Fibroblast cell strains were established and used to study residual DNA double strand breaks, using PFGE.Results: There were significant correlations between the DNA assay results and the fibrosis score (r s =0.46; P=0.003), the combined fibrosis and retraction score (r s =0.45, P=0.004) and the overall LENT score (r s =0.43; P=0.006). Using polychotomous logistic regression, the fibroblast DNA assay result was an independent prognostic factor for fibrosis severity.Conclusions: There is a relationship between residual radiation-induced DNA damage in fibroblasts and the severity of the late normal tissue damage seen in the patients from whom the cells were cultured. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)
High accurate volume holographic correlator with 4000 parallel correlation channels
Ni, Kai; Qu, Zongyao; Cao, Liangcai; Su, Ping; He, Qingsheng; Jin, Guofan
2008-03-01
Volume holographic correlator allows simultaneously calculate the two-dimensional inner product between the input image and each stored image. We have recently experimentally implemented in VHC 4000 parallel correlation channels with better than 98% output accuracy in a single location in a crystal. The speckle modulation is used to suppress the sidelobes of the correlation patterns, allowing more correlation spots to be contained in the output plane. A modified exposure schedule is designed to ensure the hologram in each channel with unity diffraction efficiency. In this schedule, a restricted coefficient was introduced into the original exposure schedule to solve the problem that the sensitivity and time constant of the crystal will change as a time function when in high-capacity storage. An interleaving method is proposed to improve the output accuracy. By unifying the distribution of the input and stored image patterns without changing the inner products between them, this method could eliminate the impact of correlation pattern variety on calculated inner product values. Moreover, by using this method, the maximum correlation spot size is reduced, which decreases the required minimum safe clearance between neighboring spots in the output plane, allowing more spots to be parallely detected without crosstalk. The experimental results are given and analyzed.
Two pion correlation from SPACER
International Nuclear Information System (INIS)
Csoergoe, T.; Zimanyi, J.; Pratt, S.
1989-12-01
The correlation function for neutral and negative pions produced in ultrarelativistic heavy ion collisions was calculated without free parameters based on a space-time version of the LUND model, called SPACER: Simulation of Phase space distribution of Atomic nuclear Collisions in Energetic Reactions. This method includes the effect of Bose correlations for the emitted pion pair. Effects arising from correlations between space-time and momentum space distributions are investigated. The results are compared to the data of two different experiments. The role and interpretation of the chaocity parameter are discussed. (D.G.) 14 refs.; 4 figs
Correlation and simple linear regression.
Zou, Kelly H; Tuncali, Kemal; Silverman, Stuart G
2003-06-01
In this tutorial article, the concepts of correlation and regression are reviewed and demonstrated. The authors review and compare two correlation coefficients, the Pearson correlation coefficient and the Spearman rho, for measuring linear and nonlinear relationships between two continuous variables. In the case of measuring the linear relationship between a predictor and an outcome variable, simple linear regression analysis is conducted. These statistical concepts are illustrated by using a data set from published literature to assess a computed tomography-guided interventional technique. These statistical methods are important for exploring the relationships between variables and can be applied to many radiologic studies.
Nonidentical particle correlations in STAR
Erazmus, B; Renault, G; Retière, F; Szarwas, P; 10.1556/APH.21.2004.2-4.33
2004-01-01
The correlation function of nonidentical particles is sensitive to the relative space-time asymmetries in particle emission. Analysing pion-kaon, pion-proton and kaon-proton correlation functions, measured in the Au+Au collisions by the STAR experiment at RHIC, we show that pions, kaons and protons are not emitted at the same average space-time coordinates. The shifts between pion, kaon and proton sources are consistent with the picture of a transverse collective flow. Results of the first measurement of proton-lambda correlations at STAR are in agreement with recent CERN and AGS data.
Ring correlations in random networks.
Sadjadi, Mahdi; Thorpe, M F
2016-12-01
We examine the correlations between rings in random network glasses in two dimensions as a function of their separation. Initially, we use the topological separation (measured by the number of intervening rings), but this leads to pseudo-long-range correlations due to a lack of topological charge neutrality in the shells surrounding a central ring. This effect is associated with the noncircular nature of the shells. It is, therefore, necessary to use the geometrical distance between ring centers. Hence we find a generalization of the Aboav-Weaire law out to larger distances, with the correlations between rings decaying away when two rings are more than about three rings apart.
Correlation methods in cutting arcs
Energy Technology Data Exchange (ETDEWEB)
Prevosto, L; Kelly, H, E-mail: prevosto@waycom.com.ar [Grupo de Descargas Electricas, Departamento Ing. Electromecanica, Universidad Tecnologica Nacional, Regional Venado Tuerto, Laprida 651, Venado Tuerto (2600), Santa Fe (Argentina)
2011-05-01
The present work applies similarity theory to the plasma emanating from transferred arc, gas-vortex stabilized plasma cutting torches, to analyze the existing correlation between the arc temperature and the physical parameters of such torches. It has been found that the enthalpy number significantly influence the temperature of the electric arc. The obtained correlation shows an average deviation of 3% from the temperature data points. Such correlation can be used, for instance, to predict changes in the peak value of the arc temperature at the nozzle exit of a geometrically similar cutting torch due to changes in its operation parameters.
Correlation methods in cutting arcs
International Nuclear Information System (INIS)
Prevosto, L; Kelly, H
2011-01-01
The present work applies similarity theory to the plasma emanating from transferred arc, gas-vortex stabilized plasma cutting torches, to analyze the existing correlation between the arc temperature and the physical parameters of such torches. It has been found that the enthalpy number significantly influence the temperature of the electric arc. The obtained correlation shows an average deviation of 3% from the temperature data points. Such correlation can be used, for instance, to predict changes in the peak value of the arc temperature at the nozzle exit of a geometrically similar cutting torch due to changes in its operation parameters.
Weak Measurement and Quantum Correlation
Indian Academy of Sciences (India)
Arun Kumar Pati
Entanglement: Two quantum systems can be in a strongly correlated state even if .... These are resources which can be used to design quantum computer, quantum ...... Weak measurements have found numerous applications starting from the ...
Jet-quenching and correlations
Indian Academy of Sciences (India)
2015-05-06
May 6, 2015 ... pseudorapidity (ridge) correlations in small systems. Section 7 ... words of 'jet' and 'parton' are often used interchangeably. ...... [118] STAR Collaboration: Joshua Konzer, Poster presentation at Quark Matter 2012 (2012).
Frequency-Modulation Correlation Spectrometer
Margolis, J. S.; Martonchik, J. V.
1985-01-01
New type of correlation spectrometer eliminates need to shift between two cells, one empty and one containing reference gas. Electrooptical phase modulator sinusoidally shift frequencies of sample transmission spectrum.
Pooling and correlated neural activity
Directory of Open Access Journals (Sweden)
Robert Rosenbaum
2010-04-01
Full Text Available Correlations between spike trains can strongly modulate neuronal activity and affect the ability of neurons to encode information. Neurons integrate inputs from thousands of afferents. Similarly, a number of experimental techniques are designed to record pooled cell activity. We review and generalize a number of previous results that show how correlations between cells in a population can be amplified and distorted in signals that reflect their collective activity. The structure of the underlying neuronal response can significantly impact correlations between such pooled signals. Therefore care needs to be taken when interpreting pooled recordings, or modeling networks of cells that receive inputs from large presynaptic populations. We also show that the frequently observed runaway synchrony in feedforward chains is primarily due to the pooling of correlated inputs.
Transverse correlations in multiphoton entanglement
International Nuclear Information System (INIS)
Wen Jianming; Rubin, Morton H.; Shih Yanhua
2007-01-01
We have analyzed the transverse correlation in multiphoton entanglement. The generalization of quantum ghost imaging is extended to the N-photon state. The Klyshko's two-photon advanced-wave picture is generalized to the N-photon case
Integrated Factors Correlating Undergraduate Academic ...
African Journals Online (AJOL)
Integrated Factors Correlating Undergraduate Academic Achievement in Bayelsa State, Nigeria. ... AFRREV IJAH: An International Journal of Arts and Humanities ... Thus, it is study investigated the integrated factors determining academic performance of students in public secondary schools in Bayelsa State, Nigeria.
Reliable computation from contextual correlations
Oestereich, André L.; Galvão, Ernesto F.
2017-12-01
An operational approach to the study of computation based on correlations considers black boxes with one-bit inputs and outputs, controlled by a limited classical computer capable only of performing sums modulo-two. In this setting, it was shown that noncontextual correlations do not provide any extra computational power, while contextual correlations were found to be necessary for the deterministic evaluation of nonlinear Boolean functions. Here we investigate the requirements for reliable computation in this setting; that is, the evaluation of any Boolean function with success probability bounded away from 1 /2 . We show that bipartite CHSH quantum correlations suffice for reliable computation. We also prove that an arbitrarily small violation of a multipartite Greenberger-Horne-Zeilinger noncontextuality inequality also suffices for reliable computation.
Default probabilities and default correlations
Erlenmaier, Ulrich; Gersbach, Hans
2001-01-01
Starting from the Merton framework for firm defaults, we provide the analytics and robustness of the relationship between default correlations. We show that loans with higher default probabilities will not only have higher variances but also higher correlations between loans. As a consequence, portfolio standard deviation can increase substantially when loan default probabilities rise. This result has two important implications. First, relative prices of loans with different default probabili...
Quantum games with correlated noise
International Nuclear Information System (INIS)
Nawaz, Ahmad; Toor, A H
2006-01-01
We analyse quantum games with correlated noise through a generalized quantization scheme. Four different combinations on the basis of entanglement of initial quantum state and the measurement basis are analysed. It is shown that the quantum player only enjoys an advantage over the classical player when both the initial quantum state and the measurement basis are in entangled form. Furthermore, it is shown that for maximum correlation the effects of decoherence diminish and it behaves as a noiseless game
Retention capacity of correlated surfaces.
Schrenk, K J; Araújo, N A M; Ziff, R M; Herrmann, H J
2014-06-01
We extend the water retention model [C. L. Knecht et al., Phys. Rev. Lett. 108, 045703 (2012)] to correlated random surfaces. We find that the retention capacity of discrete random landscapes is strongly affected by spatial correlations among the heights. This phenomenon is related to the emergence of power-law scaling in the lake volume distribution. We also solve the uncorrelated case exactly for a small lattice and present bounds on the retention of uncorrelated landscapes.
Retention capacity of correlated surfaces
Schrenk, K. J.; Araújo, N. A. M.; Ziff, R. M.; Herrmann, H. J.
2014-01-01
We extend the water retention model [C. L. Knecht et al., Phys. Rev. Lett. 108, 045703 (2012)] to correlated random surfaces. We find that the retention capacity of discrete random landscapes is strongly affected by spatial correlations among the heights. This phenomenon is related to the emergence of power-law scaling in the lake volume distribution. We also solve the uncorrelated case exactly for a small lattice and present bounds on the retention of uncorrelated landscapes.
Generating series for GUE correlators
Dubrovin, Boris; Yang, Di
2017-11-01
We extend to the Toda lattice hierarchy the approach of Bertola et al. (Phys D Nonlinear Phenom 327:30-57, 2016; IMRN, 2016) to computation of logarithmic derivatives of tau-functions in terms of the so-called matrix resolvents of the corresponding difference Lax operator. As a particular application we obtain explicit generating series for connected GUE correlators. On this basis an efficient recursive procedure for computing the correlators in full genera is developed.
Rapidity correlations test stochastic hydrodynamics
International Nuclear Information System (INIS)
Zin, C; Gavin, S; Moschelli, G
2017-01-01
We show that measurements of the rapidity dependence of transverse momentum correlations can be used to determine the characteristic time τ π that dictates the rate of isotropization of the stress energy tensor, as well as the shear viscosity ν = η/sT . We formulate methods for computing these correlations using second order dissipative hydrodynamics with noise. Current data are consistent with τ π /ν ∼ 10 but targeted measurements can improve this precision. (paper)
Manifold Regularized Correlation Object Tracking
Hu, Hongwei; Ma, Bo; Shen, Jianbing; Shao, Ling
2017-01-01
In this paper, we propose a manifold regularized correlation tracking method with augmented samples. To make better use of the unlabeled data and the manifold structure of the sample space, a manifold regularization-based correlation filter is introduced, which aims to assign similar labels to neighbor samples. Meanwhile, the regression model is learned by exploiting the block-circulant structure of matrices resulting from the augmented translated samples over multiple base samples cropped fr...
Correlated Default and Financial Intermediation
Gregory Phelan
2015-01-01
Financial intermediation naturally arises when knowledge about the aggregate state is valuable for managing investments and lenders cannot easily observe the aggregate state. I show this using a costly enforcement model in which lenders need ex-post incentives to enforce payments from defaulted loans and borrowers' payoffs are correlated. When projects have correlated outcomes, learning the state of one project (via enforcement) provides information about the states of other projects. A large...
Long-range correlated percolation
International Nuclear Information System (INIS)
Weinrib, A.
1984-01-01
This paper is a study of the percolation problem with long-range correlations in the site or bond occupations. An extension of the Harris criterion for the relevance of the correlations is derived for the case that the correlations decay as x/sup -a/ for large distances x. For a d the correlations are relevant if dν-2<0. Applying this criterion to the behavior that results when the correlations are relevant, we argue that the new behavior will have ν/sub long/ = 2/a. It is shown that the correlated bond percolation problem is equivalent to a q-state Potts model with quenched disorder in the limit q→1. With the use of this result, a renormalization-group study of the problem is presented, expanding in epsilon = 6-d and in delta = 4-a. In addition to the normal percolation fixed point, we find a new long-range fixed point. The crossover to this new fixed point follows the extended Harris criterion, and the fixed point has exponents ν/sub long/ = 2/a (as predicted) and eta/sub long/ = (1/11)(delta-epsilon). Finally, several results on the percolation properties of the Ising model at its critical point are shown to be in agreement with the predictions of this paper
Generalized drift-flux correlation
International Nuclear Information System (INIS)
Takeuchi, K.; Young, M.Y.; Hochreiter, L.E.
1991-01-01
A one-dimensional drift-flux model with five conservation equations is frequently employed in major computer codes, such as TRAC-PD2, and in simulator codes. In this method, the relative velocity between liquid and vapor phases, or slip ratio, is given by correlations, rather than by direct solution of the phasic momentum equations, as in the case of the two-fluid model used in TRAC-PF1. The correlations for churn-turbulent bubbly flow and slug flow regimes were given in terms of drift velocities by Zuber and Findlay. For the annular flow regime, the drift velocity correlations were developed by Ishii et al., using interphasic force balances. Another approach is to define the drift velocity so that flooding and liquid hold-up conditions are properly simulated, as reported here. The generalized correlation is used to reanalyze the MB-2 test data for two-phase flow in a large-diameter pipe. The results are applied to the generalized drift flux velocity, whose relationship to the other correlations is discussed. Finally, the generalized drift flux correlation is implemented in TRAC-PD2. Flow reversal from countercurrent to cocurrent flow is computed in small-diameter U-shaped tubes and is compared with the flooding curve
Spin correlations in quantum wires
Sun, Chen; Pokrovsky, Valery L.
2015-04-01
We consider theoretically spin correlations in a one-dimensional quantum wire with Rashba-Dresselhaus spin-orbit interaction (RDI). The correlations of noninteracting electrons display electron spin resonance at a frequency proportional to the RDI coupling. Interacting electrons, upon varying the direction of the external magnetic field, transit from the state of Luttinger liquid (LL) to the spin-density wave (SDW) state. We show that the two-time total-spin correlations of these states are significantly different. In the LL, the projection of total spin to the direction of the RDI-induced field is conserved and the corresponding correlator is equal to zero. The correlators of two components perpendicular to the RDI field display a sharp electron-spin resonance driven by the RDI-induced intrinsic field. In contrast, in the SDW state, the longitudinal projection of spin dominates, whereas the transverse components are suppressed. This prediction indicates a simple way for an experimental diagnostic of the SDW in a quantum wire. We point out that the Luttinger model does not respect the spin conservation since it assumes the infinite Fermi sea. We propose a proper cutoff to correct this failure.
Community Detection for Correlation Matrices
Directory of Open Access Journals (Sweden)
Mel MacMahon
2015-04-01
Full Text Available A challenging problem in the study of complex systems is that of resolving, without prior information, the emergent, mesoscopic organization determined by groups of units whose dynamical activity is more strongly correlated internally than with the rest of the system. The existing techniques to filter correlations are not explicitly oriented towards identifying such modules and can suffer from an unavoidable information loss. A promising alternative is that of employing community detection techniques developed in network theory. Unfortunately, this approach has focused predominantly on replacing network data with correlation matrices, a procedure that we show to be intrinsically biased because of its inconsistency with the null hypotheses underlying the existing algorithms. Here, we introduce, via a consistent redefinition of null models based on random matrix theory, the appropriate correlation-based counterparts of the most popular community detection techniques. Our methods can filter out both unit-specific noise and system-wide dependencies, and the resulting communities are internally correlated and mutually anticorrelated. We also implement multiresolution and multifrequency approaches revealing hierarchically nested subcommunities with “hard” cores and “soft” peripheries. We apply our techniques to several financial time series and identify mesoscopic groups of stocks which are irreducible to a standard, sectorial taxonomy; detect “soft stocks” that alternate between communities; and discuss implications for portfolio optimization and risk management.
Correlated ion stopping in plasmas
International Nuclear Information System (INIS)
Zwicknagel, G.; Deutsch, C.
1997-01-01
The basic features of correlated ion stopping in plasmas are demonstrated by employing two opposite extremes of cluster structures, a statistical model with a spatial ion distribution of Gaussian shape and the highly regular configuration of N-ion chains and cubic boxes. In the case of the ion chains the resonant character of correlated stopping due to the interference of the excited wake fields is discussed in detail. The general behavior of correlation effects is summarized and its dependence on the ratio of cluster size and interion spacing to the screening length in the plasma, as well as the ratio of the cluster velocity to the mean electron velocity in the target, is stressed out. The validity and applicability of the dielectric response formalism used for describing correlated stopping is critically reviewed. A scheme is presented to extend the linear formalism to weak nonlinear situations that occur, in particular, for small highly charged clusters at moderate or low velocities. For the Gaussian cluster a fit formula is given, which allows a fast and accurate calculation of the enhancement of stopping due to correlation effects and applies for all degrees of degeneracy of the electrons and arbitrary cluster velocities. copyright 1997 The American Physical Society
Community Detection for Correlation Matrices
MacMahon, Mel; Garlaschelli, Diego
2015-04-01
A challenging problem in the study of complex systems is that of resolving, without prior information, the emergent, mesoscopic organization determined by groups of units whose dynamical activity is more strongly correlated internally than with the rest of the system. The existing techniques to filter correlations are not explicitly oriented towards identifying such modules and can suffer from an unavoidable information loss. A promising alternative is that of employing community detection techniques developed in network theory. Unfortunately, this approach has focused predominantly on replacing network data with correlation matrices, a procedure that we show to be intrinsically biased because of its inconsistency with the null hypotheses underlying the existing algorithms. Here, we introduce, via a consistent redefinition of null models based on random matrix theory, the appropriate correlation-based counterparts of the most popular community detection techniques. Our methods can filter out both unit-specific noise and system-wide dependencies, and the resulting communities are internally correlated and mutually anticorrelated. We also implement multiresolution and multifrequency approaches revealing hierarchically nested subcommunities with "hard" cores and "soft" peripheries. We apply our techniques to several financial time series and identify mesoscopic groups of stocks which are irreducible to a standard, sectorial taxonomy; detect "soft stocks" that alternate between communities; and discuss implications for portfolio optimization and risk management.
Library correlation nuclide identification algorithm
International Nuclear Information System (INIS)
Russ, William R.
2007-01-01
A novel nuclide identification algorithm, Library Correlation Nuclide Identification (LibCorNID), is proposed. In addition to the spectrum, LibCorNID requires the standard energy, peak shape and peak efficiency calibrations. Input parameters include tolerances for some expected variations in the calibrations, a minimum relative nuclide peak area threshold, and a correlation threshold. Initially, the measured peak spectrum is obtained as the residual after baseline estimation via peak erosion, removing the continuum. Library nuclides are filtered by examining the possible nuclide peak areas in terms of the measured peak spectrum and applying the specified relative area threshold. Remaining candidates are used to create a set of theoretical peak spectra based on the calibrations and library entries. These candidate spectra are then simultaneously fit to the measured peak spectrum while also optimizing the calibrations within the bounds of the specified tolerances. Each candidate with optimized area still exceeding the area threshold undergoes a correlation test. The normalized Pearson's correlation value is calculated as a comparison of the optimized nuclide peak spectrum to the measured peak spectrum with the other optimized peak spectra subtracted. Those candidates with correlation values that exceed the specified threshold are identified and their optimized activities are output. An evaluation of LibCorNID was conducted to verify identification performance in terms of detection probability and false alarm rate. LibCorNID has been shown to perform well compared to standard peak-based analyses
Correlation-Preserving Photo Collage.
Liu, Lingjie; Zhang, Hongjie; Jing, Guangmei; Guo, Yanwen; Chen, Zhonggui; Wang, Wenping
2017-05-12
A new method is presented for producing photo collages that preserve content correlation of photos. We use deep learning techniques to find correlation among given photos to facilitate their embedding on the canvas, and develop an efficient combinatorial optimization technique to make correlated photos stay close to each other. To make efficient use of canvas space, our method first extracts salient regions of photos and packs only these salient regions. We allow the salient regions to have arbitrary shapes, therefore yielding informative, yet more compact collages than by other similar collage methods based on salient regions. We present extensive experimental results, user study results, and comparisons against the state-of-the-art methods to show the superiority of our method.
Flooding correlations in narrow channel
International Nuclear Information System (INIS)
Kim, S. H.; Baek, W. P.; Chang, S. H.
1999-01-01
Heat transfer in narrow gap is considered as important phenomena in severe accidents in nuclear power plants. Also in heat removal of electric chip. Critical heat flux(CHF) in narrow gap limits the maximum heat transfer rate in narrow channel. In case of closed bottom channel, flooding limited CHF occurrence is observed. Flooding correlations will be helpful to predict the CHF in closed bottom channel. In present study, flooding data for narrow channel geometry were collected and the work to recognize the effect of the span, w and gap size, s were performed. And new flooding correlations were suggested for high-aspect-ratio geometry. Also, flooding correlation was applied to flooding limited CHF data
Manifold Regularized Correlation Object Tracking.
Hu, Hongwei; Ma, Bo; Shen, Jianbing; Shao, Ling
2018-05-01
In this paper, we propose a manifold regularized correlation tracking method with augmented samples. To make better use of the unlabeled data and the manifold structure of the sample space, a manifold regularization-based correlation filter is introduced, which aims to assign similar labels to neighbor samples. Meanwhile, the regression model is learned by exploiting the block-circulant structure of matrices resulting from the augmented translated samples over multiple base samples cropped from both target and nontarget regions. Thus, the final classifier in our method is trained with positive, negative, and unlabeled base samples, which is a semisupervised learning framework. A block optimization strategy is further introduced to learn a manifold regularization-based correlation filter for efficient online tracking. Experiments on two public tracking data sets demonstrate the superior performance of our tracker compared with the state-of-the-art tracking approaches.
Correlated optical and isotopic nanoscopy
Saka, Sinem K.; Vogts, Angela; Kröhnert, Katharina; Hillion, François; Rizzoli, Silvio O.; Wessels, Johannes T.
2014-04-01
The isotopic composition of different materials can be imaged by secondary ion mass spectrometry. In biology, this method is mainly used to study cellular metabolism and turnover, by pulsing the cells with marker molecules such as amino acids labelled with stable isotopes (15N, 13C). The incorporation of the markers is then imaged with a lateral resolution that can surpass 100 nm. However, secondary ion mass spectrometry cannot identify specific subcellular structures like organelles, and needs to be correlated with a second technique, such as fluorescence imaging. Here, we present a method based on stimulated emission depletion microscopy that provides correlated optical and isotopic nanoscopy (COIN) images. We use this approach to study the protein turnover in different organelles from cultured hippocampal neurons. Correlated optical and isotopic nanoscopy can be applied to a variety of biological samples, and should therefore enable the investigation of the isotopic composition of many organelles and subcellular structures.
Correlations in charged bosons systems
International Nuclear Information System (INIS)
Almeida Caparica, A. de.
1985-02-01
The two and three-dimensional charge Bose gas have been studied. In the bidimensional case two different types of interaction were considered: l/r and l n(r). The method of self-consistent-field was applied to these systems, which takes into account the short range correlations between the bosons through a local-field correction. By using self-consistent numerical calculations, the structure factor S(k → ) was determined. The pair-correlation function, the ground-state energy, the pressure of the gas and the spectrum of elementary excitations were obtained from S (k → ). The screening density induced by a fixed charged impurity was calculated. In the high-density limit our calculations reproduce the results given by Bogoliubov's perturbation theory. In the intermediate-density region, corresponding to the strongly coupled systems, the results are in very good agreement with calculations based on HNC approximation as well as Monte Carlo method. The results are compared in several situations with RPA results showing that the self-consistent method is much more accurate. The two-dimensional systems showed to be more correlated than the three-dimensional systems showed to be more correlated than the three-dimensional one; the gas with interaction l/r is also more correlated than the logarithmic one at high densities, but it begins to be less correlated than this one in the low-density region. The thermodynamic functions of the two and three-dimensional systems at finite temperatures near absolute zero are calculated based upon the gas excitation spectra at zero temperature. (author)
Reveal quantum correlation in complementary bases
Shengjun Wu; Zhihao Ma; Zhihua Chen; Sixia Yu
2014-01-01
An essential feature of genuine quantum correlation is the simultaneous existence of correlation in complementary bases. We reveal this feature of quantum correlation by defining measures based on invariance under a basis change. For a bipartite quantum state, the classical correlation is the maximal correlation present in a certain optimum basis, while the quantum correlation is characterized as a series of residual correlations in the mutually unbiased bases. Compared with other approaches ...
Kinetic equations with pairing correlations
International Nuclear Information System (INIS)
Fauser, R.
1995-12-01
The Gorkov equations are derived for a general non-equilibrium system. The Gorkov factorization is generalized by the cumulant expansion of the 2-particle correlation and by a generalized Wick theorem in the case of a perturbation expansion. A stationary solution for the Green functions in the Schwinger-Keldysh formalism is presented taking into account pairing correlations. Especially the effects of collisional broadening on the spectral functions and Green functions is discussed. Kinetic equations are derived in the quasi-particle approximation and in the case of particles with width. Explicit expressions for the self-energies are given. (orig.)
Nuclear correlations and structure functions
International Nuclear Information System (INIS)
Hu Guoju; Irvine, J.M.
1989-01-01
It is argued that the search for a mass number dependence of the nuclear structure function per nucleon is profitably directed to the region of Bjorken scaling variable x > 1. We show that in the convolution model of the nuclear structure function the nuclear momentum distribution and energy spectrum generated by cluster expansion techniques, here realised in the correlated basis function method, invoking tensor correlations and short-range density-dependent repulsions adequately describes the structure function for 12 C in the region x > 1. The results of structure functions for a number of light-, medium- and heavy-mass nuclei are presented. (author)
Reliability of Roof Truss with Punched Nail Plates
DEFF Research Database (Denmark)
Hansson, Martin; Ellegaard, Peter
2005-01-01
characteristic values as input to the model. The system effect is also determined on the basis of reliability analyses. The found system effect depends on the coefficient of variation, the distribution of the random load variable and the reliability level. Depending on the assumptions, the system effect...
Growth, physiology and flowering of chrysanthemum var. Punch as ...
African Journals Online (AJOL)
Growth retardants have been proven to prevent excessive stem elongation and reduce internode length in plants by inhibiting the effect of cell division and enlargement of cell in plants. This study was aimed to evaluate the effect of concentrations of daminozide and maleic hydrazide on growth, physiology and flowering of ...
Elaboration: The Power Punch of "Body Language" Detail
Berger, Joan
2003-01-01
"Zooming in" with a camera lens led students in Joan Berger's class to enrich their writing exponentially. Through class discussion of body language, along with the use of worksheets (provided), role-playing, modeling, and conferencing, one aspect of lively writing became a part of their writing repertoire. (Contains 5 figures.)
Punching above their weight: the role of networking in SMEs
Harris, Lisa; Rae, Alan; Misner, Ivan
2011-01-01
Purpose:We draw upon the findings of a research project which investigated networking styles by owner/managers of small businesses. Our specific objective was to analyse the impact of such networking activities on business growth to develop a taxonomy of networking based on size, business model and attitudes of the owner to their use of online and offline networking.Design/methodology/approach: Our data comes from analysis of an online survey completed by 645 firms based in both the USA and E...
Research of the punch interaction with composite protective panel
Kulakov, N.; Lyubin, A.
2008-01-01
The work examines the structure of a protection composite panel consisting of a crushing layer (ceramic discrete elements of a cylindrical shape) and a restraining layer below (metallic leaf). This protection panel can be used for an armour-piercing bullet protection of the car. Here is the strength calculation of ceramic elements and metallic protective layer dynamic interaction under bullet impact. The problem was solved under a variety of protection panel parameters in order to define thei...
Punching shear strength of transversely prestressed concrete decks
Amir, S.; Van der Veen, C.; Walraven, J.C.
2012-01-01
In the Netherlands, there is a need to determine the capacity of bridge decks as a large number of them were built back in the 60’s and 70’s. Since then, not only a lot of additional safety requirements have been incorporated into the modern codes but the traffic flow has also increased drastically.
Variable Selection via Partial Correlation.
Li, Runze; Liu, Jingyuan; Lou, Lejia
2017-07-01
Partial correlation based variable selection method was proposed for normal linear regression models by Bühlmann, Kalisch and Maathuis (2010) as a comparable alternative method to regularization methods for variable selection. This paper addresses two important issues related to partial correlation based variable selection method: (a) whether this method is sensitive to normality assumption, and (b) whether this method is valid when the dimension of predictor increases in an exponential rate of the sample size. To address issue (a), we systematically study this method for elliptical linear regression models. Our finding indicates that the original proposal may lead to inferior performance when the marginal kurtosis of predictor is not close to that of normal distribution. Our simulation results further confirm this finding. To ensure the superior performance of partial correlation based variable selection procedure, we propose a thresholded partial correlation (TPC) approach to select significant variables in linear regression models. We establish the selection consistency of the TPC in the presence of ultrahigh dimensional predictors. Since the TPC procedure includes the original proposal as a special case, our theoretical results address the issue (b) directly. As a by-product, the sure screening property of the first step of TPC was obtained. The numerical examples also illustrate that the TPC is competitively comparable to the commonly-used regularization methods for variable selection.
Hadron Correlations and Parton Recombination
Energy Technology Data Exchange (ETDEWEB)
Fries, R.J. [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States)]. E-mail: rjfries@comp.tamu.edu
2007-02-15
Parton recombination has been found to be an extremely useful model to understand hadron production at the Relativistic Heavy Ion Collider. It is particularly important to explore its connections with hard processes. This article reviews some of the aspects of the quark recombination model and places particular emphasis on hadron correlations.
Correlations among static quark masses
International Nuclear Information System (INIS)
Lewin, K.; Motz, G.B.
1987-01-01
Nonrelativistic heavy quarkonia potentials with Coulomb and linearly rising limiting behaviour are correlated additively by Taylor expansion extracting the limiting structure and a constant term. Relations between fit parameters of different potentials including the quark masses m b and m c , are obtained. The known stability of the difference m b -m c , appears as direct consequence of flavour invariance of the potentials
Illusory correlation and social anxiety.
de Jong, P.J.; Boegels, S.; Kindt, M.; Merckelbach, H.
1998-01-01
An illusory correlation (IC) experiment examined the presence of a phobia-relevant covariation bias in the context of social anxiety. 60 female college students (28 with low and 32 with high social anxiety) were shown a series of slides comprising pictures of angry, happy, and neutral faces which
Spin squeezing and quantum correlations
Indian Academy of Sciences (India)
2 states. A coherent spin-s state. (CSS) θ φ can then be thought of as having no quantum correlations as the constituent. 2s elementary spins point in the same direction ˆn(θ φ) which is the mean spin direction. 2. State classification and squeezing. In order to discuss squeezing, we begin with the squeezing condition itself.
Octupole correlation effects in nuclei
International Nuclear Information System (INIS)
Chasman, R.R.
1992-01-01
Octupole correlation effects in nuclei are discussed from the point of view of many-body wavefunctions as well as mean-field methods. The light actinides, where octupole effects are largest, are considered in detail. Comparisons of theory and experiment are made for energy splittings of parity doublets; E1 transition matrix elements and one-nucleon transfer reactions
Echoes in correlated neural systems
International Nuclear Information System (INIS)
Helias, M; Tetzlaff, T; Diesmann, M
2013-01-01
Correlations are employed in modern physics to explain microscopic and macroscopic phenomena, like the fractional quantum Hall effect and the Mott insulator state in high temperature superconductors and ultracold atoms. Simultaneously probed neurons in the intact brain reveal correlations between their activity, an important measure to study information processing in the brain that also influences the macroscopic signals of neural activity, like the electroencephalogram (EEG). Networks of spiking neurons differ from most physical systems: the interaction between elements is directed, time delayed, mediated by short pulses and each neuron receives events from thousands of neurons. Even the stationary state of the network cannot be described by equilibrium statistical mechanics. Here we develop a quantitative theory of pairwise correlations in finite-sized random networks of spiking neurons. We derive explicit analytic expressions for the population-averaged cross correlation functions. Our theory explains why the intuitive mean field description fails, how the echo of single action potentials causes an apparent lag of inhibition with respect to excitation and how the size of the network can be scaled while maintaining its dynamical state. Finally, we derive a new criterion for the emergence of collective oscillations from the spectrum of the time-evolution propagator. (paper)
Correlation order, merging and diversification
Dhaene, J.; Denuit, M.; Vanduffel, S.
2009-01-01
We investigate the influence of the dependence between random losses on the shortfall and on the diversification benefit that arises from merging these losses. We prove that increasing the dependence between losses, expressed in terms of correlation order, has an increasing effect on the shortfall,
Correlation Dimension-Based Classifier
Czech Academy of Sciences Publication Activity Database
Jiřina, Marcel; Jiřina jr., M.
2014-01-01
Roč. 44, č. 12 (2014), s. 2253-2263 ISSN 2168-2267 R&D Projects: GA MŠk(CZ) LG12020 Institutional support: RVO:67985807 Keywords : classifier * multidimensional data * correlation dimension * scaling exponent * polynomial expansion Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 3.469, year: 2014
Correlation Dimension Estimation for Classification
Czech Academy of Sciences Publication Activity Database
Jiřina, Marcel; Jiřina jr., M.
2006-01-01
Roč. 1, č. 3 (2006), s. 547-557 ISSN 1895-8648 R&D Projects: GA MŠk(CZ) 1M0567 Institutional research plan: CEZ:AV0Z10300504 Keywords : correlation dimension * probability density estimation * classification * UCI MLR Subject RIV: BA - General Mathematics
Programming services with correlation sets
DEFF Research Database (Denmark)
Montesi, Fabrizio; Carbone, Marco
2011-01-01
-oriented systems, such as distribution, loose coupling, open-endedness and integration. Distinguishing features of our approach are the notion of correlation aliases and an asynchronous communication model. Our language is equipped with formal syntax, semantics, and a typing system for ensuring desirable...
Dynamics of electricity market correlations
Alvarez-Ramirez, J.; Escarela-Perez, R.; Espinosa-Perez, G.; Urrea, R.
2009-06-01
Electricity market participants rely on demand and price forecasts to decide their bidding strategies, allocate assets, negotiate bilateral contracts, hedge risks, and plan facility investments. However, forecasting is hampered by the non-linear and stochastic nature of price time series. Diverse modeling strategies, from neural networks to traditional transfer functions, have been explored. These approaches are based on the assumption that price series contain correlations that can be exploited for model-based prediction purposes. While many works have been devoted to the demand and price modeling, a limited number of reports on the nature and dynamics of electricity market correlations are available. This paper uses detrended fluctuation analysis to study correlations in the demand and price time series and takes the Australian market as a case study. The results show the existence of correlations in both demand and prices over three orders of magnitude in time ranging from hours to months. However, the Hurst exponent is not constant over time, and its time evolution was computed over a subsample moving window of 250 observations. The computations, also made for two Canadian markets, show that the correlations present important fluctuations over a seasonal one-year cycle. Interestingly, non-linearities (measured in terms of a multifractality index) and reduced price predictability are found for the June-July periods, while the converse behavior is displayed during the December-January period. In terms of forecasting models, our results suggest that non-linear recursive models should be considered for accurate day-ahead price estimation. On the other hand, linear models seem to suffice for demand forecasting purposes.
Respiratory correlated cone beam CT
International Nuclear Information System (INIS)
Sonke, Jan-Jakob; Zijp, Lambert; Remeijer, Peter; Herk, Marcel van
2005-01-01
A cone beam computed tomography (CBCT) scanner integrated with a linear accelerator is a powerful tool for image guided radiotherapy. Respiratory motion, however, induces artifacts in CBCT, while the respiratory correlated procedures, developed to reduce motion artifacts in axial and helical CT are not suitable for such CBCT scanners. We have developed an alternative respiratory correlated procedure for CBCT and evaluated its performance. This respiratory correlated CBCT procedure consists of retrospective sorting in projection space, yielding subsets of projections that each corresponds to a certain breathing phase. Subsequently, these subsets are reconstructed into a four-dimensional (4D) CBCT dataset. The breathing signal, required for respiratory correlation, was directly extracted from the 2D projection data, removing the need for an additional respiratory monitor system. Due to the reduced number of projections per phase, the contrast-to-noise ratio in a 4D scan reduced by a factor 2.6-3.7 compared to a 3D scan based on all projections. Projection data of a spherical phantom moving with a 3 and 5 s period with and without simulated breathing irregularities were acquired and reconstructed into 3D and 4D CBCT datasets. The positional deviations of the phantoms center of gravity between 4D CBCT and fluoroscopy were small: 0.13±0.09 mm for the regular motion and 0.39±0.24 mm for the irregular motion. Motion artifacts, clearly present in the 3D CBCT datasets, were substantially reduced in the 4D datasets, even in the presence of breathing irregularities, such that the shape of the moving structures could be identified more accurately. Moreover, the 4D CBCT dataset provided information on the 3D trajectory of the moving structures, absent in the 3D data. Considerable breathing irregularities, however, substantially reduces the image quality. Data presented for three different lung cancer patients were in line with the results obtained from the phantom study. In
Pion production and particle correlations
International Nuclear Information System (INIS)
Kristiansson, P.
1985-10-01
Intermediate energy heavy ion collisions have been studied using the carbon-beam produced at the CERN SC-accelerator. Cross-sections for π + and π - have been measured over a wide range of large angles at 60, 75 and 86 MeV/nucleon. The yields and shapes are compared to a nucleon-nucleon scattering approach, which underestimates the yields by orders of magnitude. The π - /π + -ratio observed is close to unity for 12 C + 12 C, but the enhancement for 12 C + 208 Pb is much larger than expected from the neutron excess in 208 Pb. Large-angle light-particle correlations for 86 MeV/nucleon carbon induced reactions on different targets (C, Al, Cu, Au) have been studied. An excess of correlations is observed in the particle-particle scattering plane. The strength of this effect increases with observed particle mass and decreases with target mass. (author)
CMS results on multijet correlations
INSPIRE-00008500
2015-04-10
We present recent measurements of multijet correlations using forward and low-$p_{\\mathrm{T}}$ jets performed by the CMS collaboration at the LHC collider. In pp collisions at $\\sqrt{s} = 7$ TeV, azimuthal correlations in dijets separated in rapidity by up to 9.4 units were measured. The results are compared to BFKL- and DGLAP-based Monte Carlo generator and analytic predictions. In pp collisions at $\\sqrt{s} = 8$ TeV, cross sections for jets with $p_{\\mathrm{T}}$ > 21 GeV and |y| 1 GeV (minijets) are presented. The minijet results are sensitive to the bound imposed by the total inelastic cross section, and are compared to various models for taming the growth of the $2 \\rightarrow 2$ cross section at low $p_{\\mathrm{T}}$.
Strongly Correlated Systems Theoretical Methods
Avella, Adolfo
2012-01-01
The volume presents, for the very first time, an exhaustive collection of those modern theoretical methods specifically tailored for the analysis of Strongly Correlated Systems. Many novel materials, with functional properties emerging from macroscopic quantum behaviors at the frontier of modern research in physics, chemistry and materials science, belong to this class of systems. Any technique is presented in great detail by its own inventor or by one of the world-wide recognized main contributors. The exposition has a clear pedagogical cut and fully reports on the most relevant case study where the specific technique showed to be very successful in describing and enlightening the puzzling physics of a particular strongly correlated system. The book is intended for advanced graduate students and post-docs in the field as textbook and/or main reference, but also for other researchers in the field who appreciates consulting a single, but comprehensive, source or wishes to get acquainted, in a as painless as po...
Strongly correlated systems numerical methods
Mancini, Ferdinando
2013-01-01
This volume presents, for the very first time, an exhaustive collection of those modern numerical methods specifically tailored for the analysis of Strongly Correlated Systems. Many novel materials, with functional properties emerging from macroscopic quantum behaviors at the frontier of modern research in physics, chemistry and material science, belong to this class of systems. Any technique is presented in great detail by its own inventor or by one of the world-wide recognized main contributors. The exposition has a clear pedagogical cut and fully reports on the most relevant case study where the specific technique showed to be very successful in describing and enlightening the puzzling physics of a particular strongly correlated system. The book is intended for advanced graduate students and post-docs in the field as textbook and/or main reference, but also for other researchers in the field who appreciate consulting a single, but comprehensive, source or wishes to get acquainted, in a as painless as possi...
Correlated uncertainties in integral data
International Nuclear Information System (INIS)
McCracken, A.K.
1978-01-01
The use of correlated uncertainties in calculational data is shown in cases investigated to lead to a reduction in the uncertainty of calculated quantities of importance to reactor design. It is stressed however that such reductions are likely to be important in a minority of cases of practical interest. The effect of uncertainties in detector cross-sections is considered and is seen to be, in some cases, of equal importance to that in the data used in calculations. Numerical investigations have been limited by the sparse information available on data correlations; some comparisons made of these data reveal quite large inconsistencies for both detector cross-sections and cross-section of interest for reactor calculations
Correlated electrons in quantum matter
Fulde, Peter
2012-01-01
An understanding of the effects of electronic correlations in quantum systems is one of the most challenging problems in physics, partly due to the relevance in modern high technology. Yet there exist hardly any books on the subject which try to give a comprehensive overview on the field covering insulators, semiconductors, as well as metals. The present book tries to fill that gap. It intends to provide graduate students and researchers a comprehensive survey of electron correlations, weak and strong, in insulators, semiconductors and metals. This topic is a central one in condensed matter and beyond that in theoretical physics. The reader will have a better understanding of the great progress which has been made in the field over the past few decades.
Bootstrapping N=2 chiral correlators
Lemos, Madalena; Liendo, Pedro
2016-01-01
We apply the numerical bootstrap program to chiral operators in four-dimensional N=2 SCFTs. In the first part of this work we study four-point functions in which all fields have the same conformal dimension. We give special emphasis to bootstrapping a specific theory: the simplest Argyres-Douglas fixed point with no flavor symmetry. In the second part we generalize our setup and consider correlators of fields with unequal dimension. This is an example of a mixed correlator and allows us to probe new regions in the parameter space of N=2 SCFTs. In particular, our results put constraints on relations in the Coulomb branch chiral ring and on the curvature of the Zamolodchikov metric.
Health correlates of workplace bullying
DEFF Research Database (Denmark)
Bonde, Jens Peter; Gullander, Maria; Hansen, Åse Marie
2016-01-01
-labelled bullying at baseline using logistic regression. RESULTS: Reports of bullying were persistent across four years in 22.2% (57/257) of employees who initially reported bullying. Baseline associations between self-labelled bullying and sick-listing, poor self-rated health, poor sleep, and depressive symptoms...... were significant with adjusted odds ratios (OR) ranging from 1.8 [95% confidence interval (95% CI) 1.5-2.4] for poor sleep quality among those bullied "now and then" to 6.9 (95% CI 3.9-12.3) for depression among those reporting being bullied on a daily to monthly basis. In longitudinal analyses...... adjusting for bullying during follow-up, all health correlates except poor sleep quality persisted up to four years. CONCLUSION: Self-reported health correlates of workplace bullying including sick-listing, poor self-rated health, depressive symptoms, and a diagnosis of depression tend to persist...
Strongly correlated systems experimental techniques
Mancini, Ferdinando
2015-01-01
The continuous evolution and development of experimental techniques is at the basis of any fundamental achievement in modern physics. Strongly correlated systems (SCS), more than any other, need to be investigated through the greatest variety of experimental techniques in order to unveil and crosscheck the numerous and puzzling anomalous behaviors characterizing them. The study of SCS fostered the improvement of many old experimental techniques, but also the advent of many new ones just invented in order to analyze the complex behaviors of these systems. Many novel materials, with functional properties emerging from macroscopic quantum behaviors at the frontier of modern research in physics, chemistry and materials science, belong to this class of systems. The volume presents a representative collection of the modern experimental techniques specifically tailored for the analysis of strongly correlated systems. Any technique is presented in great detail by its own inventor or by one of the world-wide recognize...
Correlated Electrons in Reduced Dimensions
Energy Technology Data Exchange (ETDEWEB)
Bonesteel, Nicholas E [Florida State Univ., Tallahassee, FL (United States)
2015-01-31
This report summarizes the work accomplished under the support of US DOE grant # DE-FG02-97ER45639, "Correlated Electrons in Reduced Dimensions." The underlying hypothesis of the research supported by this grant has been that studying the unique behavior of correlated electrons in reduced dimensions can lead to new ways of understanding how matter can order and how it can potentially be used. The systems under study have included i) fractional quantum Hall matter, which is realized when electrons are confined to two-dimensions and placed in a strong magnetic field at low temperature, ii) one-dimensional chains of spins and exotic quasiparticle excitations of topologically ordered matter, and iii) electrons confined in effectively ``zero-dimensional" semiconductor quantum dots.
Bootstrapping N=2 chiral correlators
Energy Technology Data Exchange (ETDEWEB)
Lemos, Madalena [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Liendo, Pedro [Humboldt-Univ. Berlin (Germany). IMIP
2015-12-15
We apply the numerical bootstrap program to chiral operators in four-dimensional N=2 SCFTs. In the first part of this work we study four-point functions in which all fields have the same conformal dimension. We give special emphasis to bootstrapping a specific theory: the simplest Argyres-Douglas fixed point with no flavor symmetry. In the second part we generalize our setup and consider correlators of fields with unequal dimension. This is an example of a mixed correlator and allows us to probe new regions in the parameter space of N=2 SCFTs. In particular, our results put constraints on relations in the Coulomb branch chiral ring and on the curvature of the Zamolodchikov metric.
Bootstrapping N=2 chiral correlators
Energy Technology Data Exchange (ETDEWEB)
Lemos, Madalena [DESY Hamburg, Theory Group,Notkestrasse 85, D-22607 Hamburg (Germany); Liendo, Pedro [IMIP, Humboldt-Universität zu Berlin, IRIS Adlershof,Zum Großen Windkanal 6, 12489 Berlin (Germany)
2016-01-07
We apply the numerical bootstrap program to chiral operators in four-dimensional N=2 SCFTs. In the first part of this work we study four-point functions in which all fields have the same conformal dimension. We give special emphasis to bootstrapping a specific theory: the simplest Argyres-Douglas fixed point with no flavor symmetry. In the second part we generalize our setup and consider correlators of fields with unequal dimension. This is an example of a mixed correlator and allows us to probe new regions in the parameter space of N=2 SCFTs. In particular, our results put constraints on relations in the Coulomb branch chiral ring and on the curvature of the Zamolodchikov metric.
Correlation dimension of financial market
Nie, Chun-Xiao
2017-05-01
In this paper, correlation dimension is applied to financial data analysis. We calculate the correlation dimensions of some real market data and find that the dimensions are significantly smaller than those of the simulation data based on geometric Brownian motion. Based on the analysis of the Chinese and US stock market data, the main results are as follows. First, by calculating three data sets for the Chinese and US market, we find that large market volatility leads to a significant decrease in the dimensions. Second, based on 5-min stock price data, we find that the Chinese market dimension is significantly larger than the US market; this shows a significant difference between the two markets for high frequency data. Third, we randomly extract stocks from a stock set and calculate the correlation dimensions, and find that the average value of these dimensions is close to the dimension of the original set. In addition, we analyse the intuitional meaning of the relevant dimensions used in this paper, which are directly related to the average degree of the financial threshold network. The dimension measures the speed of the average degree that varies with the threshold value. A smaller dimension means that the rate of change is slower.
Fibroadenomas: Sonographic-pathologic correlation
International Nuclear Information System (INIS)
Kim, Mi Sung; Choi, Hye Young; Kim, Eun Ah; Lee, Sun Wha; Sung, Soon Hee
1999-01-01
To correlate sonographic appearance and histopathologic findings of fibroadenomas. Forty-one biopsy-proven fibroadenomas were retrospectively evaluate for sonographic-pathologic correlation. The fibroadenomas were histologically classified into sclerotic, myxoid, glandular and mixed type. The stromal cellularity and fibrosis were also classified into mild and severe. The internal echotexture and posterior acoustic enhancement of mass in ultrasonogram were correlated with histopathologic findings. The pathologic types of fibroadenomas were sclerotic in sixteen, myxoid in thirteen, and glandular or mixed in each of six cases. Most of the sclerotic type showed hypoechoic internal echotexture (68.8%) and myxoid and glandular types showed isoechoic internal echotexture (84.6%, 83.3% respectively). The hypoechoic masses showed 12 cases of mild (75.0%) and 4 cases of severe (25.0%) in cellularity and 3 cases of mild (18.7%) and 13 cases (81.3%) of sever degree in fibrosis. Most of the myxoid type (77%) showed posterior enhancement, and most of the sclerotic type (87.5%) did not show posterior enhancement on ultrasonogram. Posterior enhancement was absent in 22 cases, in which 4 cases (18.2%) showed mild and 18 cases (81.2%) showed severe degree of fibrosis. Sclerotic type with mild cellularity and severe fibrosis on histopathology showed hypoechogenicity on ultrasonogram; whereas myxoid and glandular types were predominantly isoechoic. Most of the myxoid type showed posterior enhancement. Sclerotic type with mild cellularity and severe fibrosis did not show posterior enhancement.
Correlated Temporal and Spectral Variability
Swank, Jean H.
2007-01-01
The variability of neutron star and black hole X-ray sources has several dimensions, because of the roles played by different important time-scales. The variations on time scales of hours, weeks, and months, ranging from 50% to orders of magnitude, arise out of changes in the flow in the disk. The most important driving forces for those changes are probably various possible instabilities in the disk, though there may be effects with other dominant causes. The changes in the rate of flow appear to be associated with changes in the flow's configuration, as the accreting material approaches the compact object, for there are generally correlated changes in both the Xray spectra and the character of the faster temporal variability. There has been a lot of progress in tracking these correlations, both for Z and Atoll neutron star low-mass X-ray binaries, and for black hole binaries. I will discuss these correlations and review briefly what they tell us about the physical states of the systems.
Wolfram syndrome: a clinicopathologic correlation.
Hilson, Justin B; Merchant, Saumil N; Adams, Joe C; Joseph, Jeffrey T
2009-09-01
Wolfram syndrome or DIDMOAD (diabetes insipidus, diabetes mellitus, optic atrophy and deafness) is a neurodegenerative disorder characterized by diabetes mellitus and optic atrophy as well as diabetes insipidus and deafness in many cases. We report the post-mortem neuropathologic findings of a patient with Wolfram syndrome and correlate them with his clinical presentation. In the hypothalamus, neurons in the paraventricular and supraoptic nuclei were markedly decreased and minimal neurohypophyseal tissue remained in the pituitary. The pontine base and inferior olivary nucleus showed gross shrinkage and neuron loss, while the cerebellum was relatively unaffected. The visual system had moderate to marked loss of retinal ganglion neurons, commensurate loss of myelinated axons in the optic nerve, chiasm and tract, and neuron loss in the lateral geniculate nucleus but preservation of the primary visual cortex. The patient's inner ear showed loss of the organ of Corti in the basal turn of the cochleae and mild focal atrophy of the stria vascularis. These findings correlated well with the patient's high-frequency hearing loss. The pathologic findings correlated closely with the patient's clinical symptoms and further support the concept of Wolfram syndrome as a neurodegenerative disorder. Our findings extend prior neuropathologic reports of Wolfram syndrome by providing contributions to our understanding of eye, inner ear and olivopontine pathology in this disease.
PREFACE: Strongly correlated electron systems Strongly correlated electron systems
Saxena, Siddharth S.; Littlewood, P. B.
2012-07-01
This special section is dedicated to the Strongly Correlated Electron Systems Conference (SCES) 2011, which was held from 29 August-3 September 2011, in Cambridge, UK. SCES'2011 is dedicated to 100 years of superconductivity and covers a range of topics in the area of strongly correlated systems. The correlated electronic and magnetic materials featured include f-electron based heavy fermion intermetallics and d-electron based transition metal compounds. The selected papers derived from invited presentations seek to deepen our understanding of the rich physical phenomena that arise from correlation effects. The focus is on quantum phase transitions, non-Fermi liquid phenomena, quantum magnetism, unconventional superconductivity and metal-insulator transitions. Both experimental and theoretical work is presented. Based on fundamental advances in the understanding of electronic materials, much of 20th century materials physics was driven by miniaturisation and integration in the electronics industry to the current generation of nanometre scale devices. The achievements of this industry have brought unprecedented advances to society and well-being, and no doubt there is much further to go—note that this progress is founded on investments and studies in the fundamentals of condensed matter physics from more than 50 years ago. Nevertheless, the defining challenges for the 21st century will lie in the discovery in science, and deployment through engineering, of technologies that can deliver the scale needed to have an impact on the sustainability agenda. Thus the big developments in nanotechnology may lie not in the pursuit of yet smaller transistors, but in the design of new structures that can revolutionise the performance of solar cells, batteries, fuel cells, light-weight structural materials, refrigeration, water purification, etc. The science presented in the papers of this special section also highlights the underlying interest in energy-dense materials, which
Electron-gamma directional correlations; Correlations directionnelles electron-gamma
Energy Technology Data Exchange (ETDEWEB)
Gerholm, T R [Commissariat a l' Energie Atomique, Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)
1966-10-01
The theory of the angular correlation between conversion electrons and gamma rays is briefly outlined. The experimental methods used for the study of the electron-gamma correlation are described. The effects of the formation of a hole and the hyperfine structure magnetic coupling dependent on time are then considered. The experimental results showed that the attenuations found for different metallic media plainly conform to a simple quadrupolar interaction mechanism. For a source surrounded by an insulator, however, the results show that a rapidly disappearing coupling occurs as a supplement to the quadrupolar interaction mechanism. This coupling attenuates the angular correlation by about 75% of the non-perturbed value. It was concluded that for an intermediate half life of the level of the order of the nanosecond, the attenuations produced by the secondary effects of the hole formation can not be completely neglected. The metallic media considered were Ag, Au, Al, and Ga. In the study of E2 conversion processes, the radical matrix elements governing the E2 conversion process in the 412-KeV transition of {sup 198}Hg were determined. The results exclude the presence of dynamic contributions within the limits of experimental error. The values b{sub 2} (E2) and {alpha}-k (E2) obtained indirectly from the experimentally determined b{sub 4} particle parameter are in complete agreement with the theoretical values obtained by applying the corrections due to the shielding effect and to the finite dimension of the nucleus and excluding the dynamic contributions. The value for the internal conversion coefficient was also in good agreement. Experimental results from the intensity ratios between the peak and the continuum, however, seem to show significant deviations with respect to other experimental and theoretical values. There is good agreement between experimental and theoretical results on the internal conversion of {sup 203}Tl, {sup 201}Tl, and {sup 181}Ta. The theory
Organizational Design Correlates of Entrepreneurship
DEFF Research Database (Denmark)
Foss, Nicolai Juul; Lyngsie, Jacob; Zahra, Shaker A.
2015-01-01
Extant research offers relatively little insight into the organizational design correlates of entrepreneurship in established firms. We argue on theoretical grounds that the same organizational designs support the realization as well as the discovery of opportunities. Specifically, decentralized...... these organizational design variables are related to opportunity discovery. We find similar effects. We discuss the theoretical and practical implications of our reasoning and results, such as implications for the idea in the innovation and organizational learning literatures that optimal performance over time...... requires that firms either vacillate between organizational designs or adopt ambidextrous designs....
Correlations between interacting Rydberg atoms
DEFF Research Database (Denmark)
Paris-Mandoki, Asaf; Braun, Christoph; Hofferberth, Sebastian
2018-01-01
This paper is a short introduction to Rydberg physics and quantum nonlinear optics using Rydberg atoms. It has been prepared as a compliment to a series of lectures delivered during the Latin American School of Physics "Marcos Moshinsky" 2017. We provide a short introduction to the properties...... of individual Rydberg atoms and discuss in detail how the interaction potential between Rydberg atom pairs is calculated. We then discuss how this interaction gives rise to the Rydberg blockade mechanism. With the aid of hallmark experiments in the field applications of the blockade for creating correlated...
Electron correlations in quantum dots
International Nuclear Information System (INIS)
Tipton, Denver Leonard John
2001-01-01
Quantum dot structures confine electrons in a small region of space. Some properties of semiconductor quantum dots, such as the discrete energy levels and shell filling effects visible in addition spectra, have analogies to those of atoms and indeed dots are sometimes referred to as 'artificial atoms'. However, atoms and dots show some fundamental differences due to electron correlations. For real atoms, the kinetic energy of electrons dominates over their mutual Coulomb repulsion energy and for this reason the independent electron approximation works well. For quantum dots the confining potential may be shallower than that of real atoms leading to lower electron densities and a dominance of mutual Coulomb repulsion over kinetic energy. In this strongly correlated regime the independent electron picture leads to qualitatively incorrect results. This thesis concentrates on few-electron quantum dots in the strongly correlated regime both for quasi-one-dimensional and two-dimensional dots in a square confining potential. In this so-called 'Wigner' regime the ground-state electronic charge density is localised near positions of classical electrostatic minima and the interacting electronic spectrum consists of well separated spin multiplets. In the strongly correlated regime the structure of low-energy multiplets is explained by mapping onto lattice models with extended-Hubbard and Heisenberg effective Hamiltonians. The parameters for these effective models are calculated within a Hartree approximation and are shown to reproduce well the exact results obtained by numerical diagonalisation of the full interacting Hamiltonian. Comparison is made between square dots and quantum rings with full rotational symmetry. In the very low-density regime, direct diagonalisation becomes impractical due to excessive computer time for convergence. In this regime a numerical renormalisation group method is applied to one-dimensional dots, enabling effective spin-interactions to be
BMN correlators by loop equations
International Nuclear Information System (INIS)
Eynard, Bertrand; Kristjansen, Charlotte
2002-01-01
In the BMN approach to N=4 SYM a large class of correlators of interest are expressible in terms of expectation values of traces of words in a zero-dimensional gaussian complex matrix model. We develop a loop-equation based, analytic strategy for evaluating such expectation values to any order in the genus expansion. We reproduce the expectation values which were needed for the calculation of the one-loop, genus one correction to the anomalous dimension of BMN-operators and which were earlier obtained by combinatorial means. Furthermore, we present the expectation values needed for the calculation of the one-loop, genus two correction. (author)
Correlator optical wavefront sensor COWS
1991-02-01
This report documents the significant upgrades and improvements made to the correlator optical wavefront sensor (COWS) optical bench during this phase of the program. Software for the experiment was reviewed and documented. Flowcharts showing the program flow are included as well as documentation for programs which were written to calculate and display Zernike polynomials. The system was calibrated and aligned and a series of experiments to determine the optimum settings for the input and output MOSLM polarizers were conducted. In addition, design of a simple aberration generation is included.
EDITORIAL: Strongly correlated electron systems Strongly correlated electron systems
Ronning, Filip; Batista, Cristian
2011-03-01
Strongly correlated electrons is an exciting and diverse field in condensed matter physics. This special issue aims to capture some of that excitement and recent developments in the field. Given that this issue was inspired by the 2010 International Conference on Strongly Correlated Electron Systems (SCES 2010), we briefly give some history in order to place this issue in context. The 2010 International Conference on Strongly Correlated Electron Systems was held in Santa Fe, New Mexico, a reunion of sorts from the 1989 International Conference on the Physics of Highly Correlated Electron Systems that also convened in Santa Fe. SCES 2010—co-chaired by John Sarrao and Joe Thompson—followed the tradition of earlier conferences, in this century, hosted by Buzios (2008), Houston (2007), Vienna (2005), Karlsruhe (2004), Krakow (2002) and Ann Arbor (2001). Every three years since 1997, SCES has joined the International Conference on Magnetism (ICM), held in Recife (2000), Rome (2003), Kyoto (2006) and Karlsruhe (2009). Like its predecessors, SCES 2010 topics included strongly correlated f- and d-electron systems, heavy-fermion behaviors, quantum-phase transitions, non-Fermi liquid phenomena, unconventional superconductivity, and emergent states that arise from electronic correlations. Recent developments from studies of quantum magnetism and cold atoms complemented the traditional subjects and were included in SCES 2010. 2010 celebrated the 400th anniversary of Santa Fe as well as the birth of astronomy. So what's the connection to SCES? The Dutch invention of the first practical telescope and its use by Galileo in 1610 and subsequent years overturned dogma that the sun revolved about the earth. This revolutionary, and at the time heretical, conclusion required innovative combinations of new instrumentation, observation and mathematics. These same combinations are just as important 400 years later and are the foundation of scientific discoveries that were discussed
The dynamics of correlated novelties.
Tria, F; Loreto, V; Servedio, V D P; Strogatz, S H
2014-07-31
Novelties are a familiar part of daily life. They are also fundamental to the evolution of biological systems, human society, and technology. By opening new possibilities, one novelty can pave the way for others in a process that Kauffman has called "expanding the adjacent possible". The dynamics of correlated novelties, however, have yet to be quantified empirically or modeled mathematically. Here we propose a simple mathematical model that mimics the process of exploring a physical, biological, or conceptual space that enlarges whenever a novelty occurs. The model, a generalization of Polya's urn, predicts statistical laws for the rate at which novelties happen (Heaps' law) and for the probability distribution on the space explored (Zipf's law), as well as signatures of the process by which one novelty sets the stage for another. We test these predictions on four data sets of human activity: the edit events of Wikipedia pages, the emergence of tags in annotation systems, the sequence of words in texts, and listening to new songs in online music catalogues. By quantifying the dynamics of correlated novelties, our results provide a starting point for a deeper understanding of the adjacent possible and its role in biological, cultural, and technological evolution.
Correlation Models for Temperature Fields
North, Gerald R.
2011-05-16
This paper presents derivations of some analytical forms for spatial correlations of evolving random fields governed by a white-noise-driven damped diffusion equation that is the analog of autoregressive order 1 in time and autoregressive order 2 in space. The study considers the two-dimensional plane and the surface of a sphere, both of which have been studied before, but here time is introduced to the problem. Such models have a finite characteristic length (roughly the separation at which the autocorrelation falls to 1/e) and a relaxation time scale. In particular, the characteristic length of a particular temporal Fourier component of the field increases to a finite value as the frequency of the particular component decreases. Some near-analytical formulas are provided for the results. A potential application is to the correlation structure of surface temperature fields and to the estimation of large area averages, depending on how the original datastream is filtered into a distribution of Fourier frequencies (e.g., moving average, low pass, or narrow band). The form of the governing equation is just that of the simple energy balance climate models, which have a long history in climate studies. The physical motivation provided by the derivation from a climate model provides some heuristic appeal to the approach and suggests extensions of the work to nonuniform cases.
Perturbed angular correlations and distributions
International Nuclear Information System (INIS)
Makaryunas, K.
1976-01-01
The present index comprises original works and review papers on the perturbed angular correlations (PAC) and distributions (PAD). The articles published in the Soviet and foreign journals as well as the materials of conferences, monographs and collections published in the USSR and abroad, the preprints produced by various institutes and abstracts of disertations are included from 1948 up to 1973. The whole material compiled in this index is divided into three parts. Part one is a bibliographic index. All papers in this part are divided into three sections. Section one comprises the papers devoted to the theoretical works on PAC, review papers, monographs, materials of conferences. Section two deals with the works of methodical character where correlation spectrometers as well as the treatment of experimental data are described. In section three experimental works with concrete nuclei are compiled. Part two gives the characteristic of works performed with concrete nuclei. This part is presented in the form of the table in which the works are systematized according to the chemical elements and isotopes. The table shows the characteristics of the nuclear levels used in the investigations by PAC as well as brief characteristics of experiments and results obtained. Part three - appendix contains alphabetic index of the authors, the list of the used editions with the abbreviations of the titles of these editions. The lists indicating the dynamic of the quantity of works on PAC and the distribution according to the literature sources are also given
Strongly correlated perovskite fuel cells
Zhou, You; Guan, Xiaofei; Zhou, Hua; Ramadoss, Koushik; Adam, Suhare; Liu, Huajun; Lee, Sungsik; Shi, Jian; Tsuchiya, Masaru; Fong, Dillon D.; Ramanathan, Shriram
2016-06-01
Fuel cells convert chemical energy directly into electrical energy with high efficiencies and environmental benefits, as compared with traditional heat engines. Yttria-stabilized zirconia is perhaps the material with the most potential as an electrolyte in solid oxide fuel cells (SOFCs), owing to its stability and near-unity ionic transference number. Although there exist materials with superior ionic conductivity, they are often limited by their ability to suppress electronic leakage when exposed to the reducing environment at the fuel interface. Such electronic leakage reduces fuel cell power output and the associated chemo-mechanical stresses can also lead to catastrophic fracture of electrolyte membranes. Here we depart from traditional electrolyte design that relies on cation substitution to sustain ionic conduction. Instead, we use a perovskite nickelate as an electrolyte with high initial ionic and electronic conductivity. Since many such oxides are also correlated electron systems, we can suppress the electronic conduction through a filling-controlled Mott transition induced by spontaneous hydrogen incorporation. Using such a nickelate as the electrolyte in free-standing membrane geometry, we demonstrate a low-temperature micro-fabricated SOFC with high performance. The ionic conductivity of the nickelate perovskite is comparable to the best-performing solid electrolytes in the same temperature range, with a very low activation energy. The results present a design strategy for high-performance materials exhibiting emergent properties arising from strong electron correlations.
Correlation Models for Temperature Fields
North, Gerald R.; Wang, Jue; Genton, Marc G.
2011-01-01
This paper presents derivations of some analytical forms for spatial correlations of evolving random fields governed by a white-noise-driven damped diffusion equation that is the analog of autoregressive order 1 in time and autoregressive order 2 in space. The study considers the two-dimensional plane and the surface of a sphere, both of which have been studied before, but here time is introduced to the problem. Such models have a finite characteristic length (roughly the separation at which the autocorrelation falls to 1/e) and a relaxation time scale. In particular, the characteristic length of a particular temporal Fourier component of the field increases to a finite value as the frequency of the particular component decreases. Some near-analytical formulas are provided for the results. A potential application is to the correlation structure of surface temperature fields and to the estimation of large area averages, depending on how the original datastream is filtered into a distribution of Fourier frequencies (e.g., moving average, low pass, or narrow band). The form of the governing equation is just that of the simple energy balance climate models, which have a long history in climate studies. The physical motivation provided by the derivation from a climate model provides some heuristic appeal to the approach and suggests extensions of the work to nonuniform cases.
The Neurogenetic Correlates of Consciousness
Grandy, John K.
2013-09-01
The neurogenetic correlates of consciousness (NgCC) is a new field of consciousness studies that focuses on genes that have an effect on or are involved in the continuum of neuron-based consciousness. A framework of consciousness based on the neural correlates of consciousness (NCC) has already been established by Francis Crick and Christof Kock. In this work I propose that there are NgCC underlying the NCC which are both active during the conscious experience. So how are genes involved? There are two significant connections between DNA and neurons that are involved in the conscious experience. First, any brain system can be adversely affected by underlying genetic abnormalities which can be expressed in an individual at birth, in adulthood, or later in life. Second, the DNA molecule does not lay dormant while the neuron runs on autopilot. DNA is active in translating and transcribing RNA and protein products that are utilized during neuron functioning. Without these products being continuously produced by the DNA during a conscious experience the neurons would cease to function correctly and be rendered unable to provide a continuum of human consciousness. Consequently, in addition to NCC, NgCC must be factored in when appreciating a conscious event. In this work I will discuss and explain some NgCC citing several examples.
Significance and properties of internucleon correlation functions
Suzuki, Y.; Horiuchi, W.
2008-01-01
We show that a nuclear Hamiltonian and a set of internucleon correlation functions is in a one-to-one correspondence. The correlation functions for $s$-shell nuclei interacting via the two-nucleon interaction of AV8$^\\prime$ type are calculated to exhibit the importance of tensor correlations as well as short-range central correlation. The asymptotic behavior of the correlation functions is also discussed.
Estimation of Correlation Functions by Random Decrement
DEFF Research Database (Denmark)
Asmussen, J. C.; Brincker, Rune
This paper illustrates how correlation functions can be estimated by the random decrement technique. Several different formulations of the random decrement technique, estimating the correlation functions are considered. The speed and accuracy of the different formulations of the random decrement...... and the length of the correlation functions. The accuracy of the estimates with respect to the theoretical correlation functions and the modal parameters are both investigated. The modal parameters are extracted from the correlation functions using the polyreference time domain technique....
Partial distance correlation with methods for dissimilarities
Székely, Gábor J.; Rizzo, Maria L.
2014-01-01
Distance covariance and distance correlation are scalar coefficients that characterize independence of random vectors in arbitrary dimension. Properties, extensions, and applications of distance correlation have been discussed in the recent literature, but the problem of defining the partial distance correlation has remained an open question of considerable interest. The problem of partial distance correlation is more complex than partial correlation partly because the squared distance covari...
Nonclassical correlations in superconducting circuits
Energy Technology Data Exchange (ETDEWEB)
Migliore, Rosanna [Dipartimento di Scienze Fisiche ed Astronomiche, Universita di Palermo (Italy); CNR-INFM, UdR CNISM di Palermo, Palermo (Italy); Scala, Matteo [Dipartimento di Scienze Fisiche ed Astronomiche, Universita di Palermo (Italy); Departamento de Optica, Facultad de Fisica, Universidad Complutense, Madrid (Spain); Guccione, Marina; Sanchez-Soto, Luis L. [Dipartimento di Scienze Fisiche ed Astronomiche, Universita di Palermo (Italy); Messina, Antonino [Departamento de Optica, Facultad de Fisica, Universidad Complutense, Madrid (Spain)
2009-05-15
A key step on the road map to solid-state quantum information processing (and to a deeper understanding of many counterintuitive aspects of quantum mechanics) is the generation and manipulation of nonclassical correlations between different quantum systems. Within this framework, we analyze the possibility of generating maximally entangled states in a system of two superconducting flux qubits, as well as the effectof their own environments on the entanglement dynamics. The analysis reported here confirms that the phenomena of sudden birth and sudden death of the entanglement do not depend on the particular measure of the entanglement adopted (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)
Correlations In Confined Quantum Plasmas
International Nuclear Information System (INIS)
Dufty, J.W.
2012-01-01
This is the final report for the project 'Correlations in Confined Quantum Plasmas', NSF-DOE Partnership Grant DE FG02 07ER54946, 8/1/2007 - 7/30/2010. The research was performed in collaboration with a group at Christian Albrechts University (CAU), Kiel, Germany. That collaboration, almost 15 years old, was formalized during the past four years under this NSF-DOE Partnership Grant to support graduate students at the two institutions and to facilitate frequent exchange visits. The research was focused on exploring the frontiers of charged particle physics evolving from new experimental access to unusual states associated with confinement. Particular attention was paid to combined effects of quantum mechanics and confinement. A suite of analytical and numerical tools tailored to the specific inquiry has been developed and employed
Correlations between interacting Rydberg atoms
Paris-Mandoki, Asaf; Braun, Christoph; Hofferberth, Sebastian
2018-04-01
This paper is a short introduction to Rydberg physics and quantum nonlinear optics using Rydberg atoms. It has been prepared as a compliment to a series of lectures delivered during the Latin American School of Physics "Marcos Moshinsky" 2017. We provide a short introduction to the properties of individual Rydberg atoms and discuss in detail how the interaction potential between Rydberg atom pairs is calculated. We then discuss how this interaction gives rise to the Rydberg blockade mechanism. With the aid of hallmark experiments in the field applications of the blockade for creating correlated quantum systems are discussed. Our aim is to give an overview of this exciting and rapidly evolving field. The interested reader is referred to original work and more comprehensive reviews and tutorials for further details on these subjects.
Health correlates of workplace bullying
DEFF Research Database (Denmark)
Bonde, Jens Peter; Gullander, Maria; Hansen, Åse Marie
2016-01-01
OBJECTIVE: This study aimed to examine the course of workplace bullying and health correlates among Danish employees across a four-year period. METHODS: In total, 7502 public service and private sector employees participated in a 3-wave study from 2006 through 2011. Workplace bullying over the past......-labelled bullying at baseline using logistic regression. RESULTS: Reports of bullying were persistent across four years in 22.2% (57/257) of employees who initially reported bullying. Baseline associations between self-labelled bullying and sick-listing, poor self-rated health, poor sleep, and depressive symptoms...... were significant with adjusted odds ratios (OR) ranging from 1.8 [95% confidence interval (95% CI) 1.5-2.4] for poor sleep quality among those bullied "now and then" to 6.9 (95% CI 3.9-12.3) for depression among those reporting being bullied on a daily to monthly basis. In longitudinal analyses...
Neuroanatomical correlates of perceived usability
DEFF Research Database (Denmark)
Vi, Chi Thanh; Hornbæk, Kasper; Subramanian, Sriram
2017-01-01
Usability has a distinct subjective component, yet surprisingly little is known about its neural basis and relation to the neuroanatomy of aesthetics. To begin closing this gap, we conducted two functional magnetic resonance imaging studies in which participants were shown static webpages (in...... the first study) and videos of interaction with webpages (in the second study). The webpages were controlled so as to exhibit high and low levels of perceived usability and perceived aesthetics. Our results show unique links between perceived usability and brain areas involved in functions such as emotional...... processing (left fusiform gyrus, superior frontal gyrus), anticipation of physical interaction (precentral gyrus), task intention (anterior cingulate cortex), and linguistic processing (medial and bilateral superior frontal gyri). We use these findings to discuss the brain correlates of perceived usability...
Correlated randomness and switching phenomena
Stanley, H. E.; Buldyrev, S. V.; Franzese, G.; Havlin, S.; Mallamace, F.; Kumar, P.; Plerou, V.; Preis, T.
2010-08-01
One challenge of biology, medicine, and economics is that the systems treated by these serious scientific disciplines have no perfect metronome in time and no perfect spatial architecture-crystalline or otherwise. Nonetheless, as if by magic, out of nothing but randomness one finds remarkably fine-tuned processes in time and remarkably fine-tuned structures in space. Further, many of these processes and structures have the remarkable feature of “switching” from one behavior to another as if by magic. The past century has, philosophically, been concerned with placing aside the human tendency to see the universe as a fine-tuned machine. Here we will address the challenge of uncovering how, through randomness (albeit, as we shall see, strongly correlated randomness), one can arrive at some of the many spatial and temporal patterns in biology, medicine, and economics and even begin to characterize the switching phenomena that enables a system to pass from one state to another. Inspired by principles developed by A. Nihat Berker and scores of other statistical physicists in recent years, we discuss some applications of correlated randomness to understand switching phenomena in various fields. Specifically, we present evidence from experiments and from computer simulations supporting the hypothesis that water’s anomalies are related to a switching point (which is not unlike the “tipping point” immortalized by Malcolm Gladwell), and that the bubbles in economic phenomena that occur on all scales are not “outliers” (another Gladwell immortalization). Though more speculative, we support the idea of disease as arising from some kind of yet-to-be-understood complex switching phenomenon, by discussing data on selected examples, including heart disease and Alzheimer disease.
Surface correlation effects in two-band strongly correlated slabs.
Esfahani, D Nasr; Covaci, L; Peeters, F M
2014-02-19
Using an extension of the Gutzwiller approximation for an inhomogeneous system, we study the two-band Hubbard model with unequal band widths for a slab geometry. The aim is to investigate the mutual effect of individual bands on the spatial distribution of quasi-particle weight and charge density, especially near the surface of the slab. The main effect of the difference in band width is the presence of two different length scales corresponding to the quasi-particle profile of each band. This is enhanced in the vicinity of the critical interaction of the narrow band where an orbitally selective Mott transition occurs and a surface dead layer forms for the narrow band. For the doped case, two different regimes of charge transfer between the surface and the bulk of the slab are revealed. The charge transfer from surface/center to center/surface depends on both the doping level and the average relative charge accumulated in each band. Such effects could also be of importance when describing the accumulation of charges at the interface between structures made of multi-band strongly correlated materials.
OPTIMAL CORRELATION ESTIMATORS FOR QUANTIZED SIGNALS
Energy Technology Data Exchange (ETDEWEB)
Johnson, M. D.; Chou, H. H.; Gwinn, C. R., E-mail: michaeltdh@physics.ucsb.edu, E-mail: cgwinn@physics.ucsb.edu [Department of Physics, University of California, Santa Barbara, CA 93106 (United States)
2013-03-10
Using a maximum-likelihood criterion, we derive optimal correlation strategies for signals with and without digitization. We assume that the signals are drawn from zero-mean Gaussian distributions, as is expected in radio-astronomical applications, and we present correlation estimators both with and without a priori knowledge of the signal variances. We demonstrate that traditional estimators of correlation, which rely on averaging products, exhibit large and paradoxical noise when the correlation is strong. However, we also show that these estimators are fully optimal in the limit of vanishing correlation. We calculate the bias and noise in each of these estimators and discuss their suitability for implementation in modern digital correlators.
OPTIMAL CORRELATION ESTIMATORS FOR QUANTIZED SIGNALS
International Nuclear Information System (INIS)
Johnson, M. D.; Chou, H. H.; Gwinn, C. R.
2013-01-01
Using a maximum-likelihood criterion, we derive optimal correlation strategies for signals with and without digitization. We assume that the signals are drawn from zero-mean Gaussian distributions, as is expected in radio-astronomical applications, and we present correlation estimators both with and without a priori knowledge of the signal variances. We demonstrate that traditional estimators of correlation, which rely on averaging products, exhibit large and paradoxical noise when the correlation is strong. However, we also show that these estimators are fully optimal in the limit of vanishing correlation. We calculate the bias and noise in each of these estimators and discuss their suitability for implementation in modern digital correlators.
The Effect of Error Correlation on Interfactor Correlation in Psychometric Measurement
Westfall, Peter H.; Henning, Kevin S. S.; Howell, Roy D.
2012-01-01
This article shows how interfactor correlation is affected by error correlations. Theoretical and practical justifications for error correlations are given, and a new equivalence class of models is presented to explain the relationship between interfactor correlation and error correlations. The class allows simple, parsimonious modeling of error…
Jensen, Berit P; Saraf, Rajneeta; Ma, Jing; Berry, Sarah; Grant, Cameron C; Camargo, Carlos A; Sies, Christiaan W
2018-06-01
Demand for measurement of 25-hydroxyvitamin D (25OHD) is growing and dried blood spot (DBS) sampling is attractive as samples are easier to collect, transport and store. A 2D LC-MS/MS assay without derivatization was developed. DBS punches (3.2 mm) were ultrasonicated with d 6 -25OHD 3 in 70% methanol followed by hexane extraction, dry-down and reconstitution. The assay was validated and applied to two studies comparing whole blood adult DBS with serum samples (n = 40) and neonatal whole blood DBS with cord serum samples (n = 80). The assay was validated in whole blood DBS over the range 13-106 nmol/L 25OHD 3 and 11-91 nmol/L 25OHD 2 with a limit of detection of 3 nmol/L. Intra- and inter-day imprecision was <13% CV and bias <12%. The assay had high recovery and minimal matrix effects. Triplicate DBS study samples had a mean CV of ≤13% for 25OHD 3. No 25OHD 2 was detected. DBS calculated serum 25OHD 3 concentrations correlated strongly with serum concentrations in the adult DBS/serum study (r = 0.94) and moderately in the neonatal DBS/cord serum study (r = 0.69). Direct quantitation of 25OHD in DBS by 2D LC-MS/MS without derivatization was found to be an alternative to serum quantitation applicable to clinical research studies on adult DBS samples. Copyright © 2018 Elsevier B.V. All rights reserved.
Modeling conditional correlations of asset returns
DEFF Research Database (Denmark)
Silvennoinen, Annastiina; Teräsvirta, Timo
2015-01-01
In this paper we propose a new multivariate GARCH model with time-varying conditional correlation structure. The time-varying conditional correlations change smoothly between two extreme states of constant correlations according to a predetermined or exogenous transition variable. An LM-test is d......In this paper we propose a new multivariate GARCH model with time-varying conditional correlation structure. The time-varying conditional correlations change smoothly between two extreme states of constant correlations according to a predetermined or exogenous transition variable. An LM......-test is derived to test the constancy of correlations and LM- and Wald tests to test the hypothesis of partially constant correlations. Analytical expressions for the test statistics and the required derivatives are provided to make computations feasible. An empirical example based on daily return series of five...
Local Descriptors of Dynamic and Nondynamic Correlation.
Ramos-Cordoba, Eloy; Matito, Eduard
2017-06-13
Quantitatively accurate electronic structure calculations rely on the proper description of electron correlation. A judicious choice of the approximate quantum chemistry method depends upon the importance of dynamic and nondynamic correlation, which is usually assesed by scalar measures. Existing measures of electron correlation do not consider separately the regions of the Cartesian space where dynamic or nondynamic correlation are most important. We introduce real-space descriptors of dynamic and nondynamic electron correlation that admit orbital decomposition. Integration of the local descriptors yields global numbers that can be used to quantify dynamic and nondynamic correlation. Illustrative examples over different chemical systems with varying electron correlation regimes are used to demonstrate the capabilities of the local descriptors. Since the expressions only require orbitals and occupation numbers, they can be readily applied in the context of local correlation methods, hybrid methods, density matrix functional theory, and fractional-occupancy density functional theory.
Generalized canonical correlation analysis with missing values
M. van de Velden (Michel); Y. Takane
2012-01-01
textabstractGeneralized canonical correlation analysis is a versatile technique that allows the joint analysis of several sets of data matrices. The generalized canonical correlation analysis solution can be obtained through an eigenequation and distributional assumptions are not required. When
Analytic matrix elements with shifted correlated Gaussians
DEFF Research Database (Denmark)
Fedorov, D. V.
2017-01-01
Matrix elements between shifted correlated Gaussians of various potentials with several form-factors are calculated analytically. Analytic matrix elements are of importance for the correlated Gaussian method in quantum few-body physics.......Matrix elements between shifted correlated Gaussians of various potentials with several form-factors are calculated analytically. Analytic matrix elements are of importance for the correlated Gaussian method in quantum few-body physics....
Spatial photon correlations in multiple scattering media
DEFF Research Database (Denmark)
Smolka, Stephan; Muskens, O.; Lagendijk, A.
2010-01-01
We present the first angle-resolved measurements of spatial photon correlations that are induced by multiple scattering of light. The correlation relates multiple scattered photons at different spatial positions and depends on incident photon fluctuations.......We present the first angle-resolved measurements of spatial photon correlations that are induced by multiple scattering of light. The correlation relates multiple scattered photons at different spatial positions and depends on incident photon fluctuations....
Local quantum channels preserving classical correlations
International Nuclear Information System (INIS)
Guo Zhihua; Cao Huaixin
2013-01-01
The aim of this paper is to discuss local quantum channels that preserve classical correlations. First, we give two equivalent characterizations of classical correlated states. Then we obtain the relationships among classical correlation-preserving local quantum channels, commutativity-preserving local quantum channels and commutativity-preserving quantum channels on each subsystem. Furthermore, for a two-qubit system, we show the general form of classical correlation-preserving local quantum channels. (paper)
Pion correlations in heavy ion collision
International Nuclear Information System (INIS)
Venema, L.
1991-01-01
Charged π-correlations are a well established experimental technique to obtain information about π-source sizes. This is, however, not the case for π 0 's, as they decay into photons, resulting in measurements of 4 photon correlations. Here is described what these correlations are, what the problems are to detect and interpret them. These correlations are an additional way to get more information out of the heavy ion collisions. (orig.)
Geometrical optics in correlated imaging systems
International Nuclear Information System (INIS)
Cao Dezhong; Xiong Jun; Wang Kaige
2005-01-01
We discuss the geometrical optics of correlated imaging for two kinds of spatial correlations corresponding, respectively, to a classical thermal light source and a quantum two-photon entangled source. Due to the different features in the second-order spatial correlation, the two sources obey different imaging equations. The quantum entangled source behaves as a mirror, whereas the classical thermal source looks like a phase-conjugate mirror in the correlated imaging
Robust canonical correlations: A comparative study
Branco, JA; Croux, Christophe; Filzmoser, P; Oliveira, MR
2005-01-01
Several approaches for robust canonical correlation analysis will be presented and discussed. A first method is based on the definition of canonical correlation analysis as looking for linear combinations of two sets of variables having maximal (robust) correlation. A second method is based on alternating robust regressions. These methods axe discussed in detail and compared with the more traditional approach to robust canonical correlation via covariance matrix estimates. A simulation study ...
Correlation coefficients in neutron β-decay
International Nuclear Information System (INIS)
Byrne, J.
1978-01-01
The various angular and polarisation coefficients in neutron decay are the principal sources of information on the β-interaction. Measurements of the electron-neutrino angular correlation coefficient (a), the neutron-spin-electron-momentum correlation coefficient (A), the neutron-spin-neutrino-momentum correlation coefficient (B), and the triple correlation coefficient D and time-reversal invariance are reviewed and the results discussed. (U.K.)
PSYCHOLOGICAL CORRELATES OF POSTPARTUM DEPRESSION
Directory of Open Access Journals (Sweden)
Anida Fazlagić
2011-12-01
Full Text Available Manual of Mental Disorders (DSM-IV, postpartum depression may include any nonpsychotic depressive disorder during the first four weeks of postpartum, according to research criteria during the first year after birth. The exact cause of postpartum depression is not yet known, and most researchers believe that postpartum depression is a bio-psycho-social problem. So far, the biological aspect of the disease is explained by changing the levels of estrogen and progesterone during pregnancy, and by decrease of hormone levels after birth. Psychological correlates are often associated with low selfesteem, pessimism as a personality trait, bad strategies of coping with stress, mood swings and emotional reactions. The social aspect of the disease is associated with the existential conditions of pregnant woman, support of partners and education level. This paper will include issues like hereditary causes and possible psychological factors of postpartum depression prevention. Nowadays, it is estimated that on average 15% of women, regardless of the pregnancy outcome, are suffering from postpartum depression. However, this information includes only those women who were diagnosed with postpartum depression and who themselves reported about it. Almost every woman receives basic care during pregnancy to prevent complications in the physiological level. This paper has shown possible psychological factors of postpartum depression prevention, the impact of optimism, self-esteem and coping skills.
Cluster Correlation in Mixed Models
Gardini, A.; Bonometto, S. A.; Murante, G.; Yepes, G.
2000-10-01
We evaluate the dependence of the cluster correlation length, rc, on the mean intercluster separation, Dc, for three models with critical matter density, vanishing vacuum energy (Λ=0), and COBE normalization: a tilted cold dark matter (tCDM) model (n=0.8) and two blue mixed models with two light massive neutrinos, yielding Ωh=0.26 and 0.14 (MDM1 and MDM2, respectively). All models approach the observational value of σ8 (and hence the observed cluster abundance) and are consistent with the observed abundance of damped Lyα systems. Mixed models have a motivation in recent results of neutrino physics; they also agree with the observed value of the ratio σ8/σ25, yielding the spectral slope parameter Γ, and nicely fit Las Campanas Redshift Survey (LCRS) reconstructed spectra. We use parallel AP3M simulations, performed in a wide box (of side 360 h-1 Mpc) and with high mass and distance resolution, enabling us to build artificial samples of clusters, whose total number and mass range allow us to cover the same Dc interval inspected through Automatic Plate Measuring Facility (APM) and Abell cluster clustering data. We find that the tCDM model performs substantially better than n=1 critical density CDM models. Our main finding, however, is that mixed models provide a surprisingly good fit to cluster clustering data.
Correlates of oral contraception continuation.
Ewer, P A; Gibbs, J O
1971-05-01
A sample of 139 predominantly black, young, low-income patients who had accepted oral contraception at a publicly supported family planning clinic has been analyzed for correlates of oral contraception continuation. Interviews were conducted 10-12 months after the clinic visit; at this time 38% of the patients continued taking oral contraceptives. It was found that patients with the highest continuation rates were 18-24 years old, in the 2-3 parity group, living with their husbands, had low-parity mothers, and were able to fill prescriptions in less time with more convenient methods of transportation. Discontinuers tended to have high-parity mothers, live with parents or head their own households, and to be in the 13-17 or 25-45 year old age groups. Fear of long-term use of oral contraceptives and perceived side effects appeared to be implicated in discontinuation. The rate of discontinuation may be associated with irregular coital experience and less consistent exposure to pregnancy.
Teaching Principal Components Using Correlations.
Westfall, Peter H; Arias, Andrea L; Fulton, Lawrence V
2017-01-01
Introducing principal components (PCs) to students is difficult. First, the matrix algebra and mathematical maximization lemmas are daunting, especially for students in the social and behavioral sciences. Second, the standard motivation involving variance maximization subject to unit length constraint does not directly connect to the "variance explained" interpretation. Third, the unit length and uncorrelatedness constraints of the standard motivation do not allow re-scaling or oblique rotations, which are common in practice. Instead, we propose to motivate the subject in terms of optimizing (weighted) average proportions of variance explained in the original variables; this approach may be more intuitive, and hence easier to understand because it links directly to the familiar "R-squared" statistic. It also removes the need for unit length and uncorrelatedness constraints, provides a direct interpretation of "variance explained," and provides a direct answer to the question of whether to use covariance-based or correlation-based PCs. Furthermore, the presentation can be made without matrix algebra or optimization proofs. Modern tools from data science, including heat maps and text mining, provide further help in the interpretation and application of PCs; examples are given. Together, these techniques may be used to revise currently used methods for teaching and learning PCs in the behavioral sciences.
Correlation functions of warped CFT
Song, Wei; Xu, Jianfei
2018-04-01
Warped conformal field theory (WCFT) is a two dimensional quantum field theory whose local symmetry algebra consists of a Virasoro algebra and a U(1) Kac-Moody algebra. In this paper, we study correlation functions for primary operators in WCFT. Similar to conformal symmetry, warped conformal symmetry is very constraining. The form of the two and three point functions are determined by the global warped conformal symmetry while the four point functions can be determined up to an arbitrary function of the cross ratio. The warped conformal bootstrap equation are constructed by formulating the notion of crossing symmetry. In the large central charge limit, four point functions can be decomposed into global warped conformal blocks, which can be solved exactly. Furthermore, we revisit the scattering problem in warped AdS spacetime (WAdS), and give a prescription on how to match the bulk result to a WCFT retarded Green's function. Our result is consistent with the conjectured holographic dualities between WCFT and WAdS.
Oscillatory correlates of autobiographical memory.
Knyazev, Gennady G; Savostyanov, Alexander N; Bocharov, Andrey V; Dorosheva, Elena A; Tamozhnikov, Sergey S; Saprigyn, Alexander E
2015-03-01
Recollection of events from one's own life is referred to as autobiographical memory. Autobiographical memory is an important part of our self. Neuroimaging findings link self-referential processes with the default mode network (DMN). Much evidence coming primarily from functional magnetic resonance imaging studies shows that autobiographical memory and DMN have a common neural base. In this study, electroencephalographic data collected in 47 participants during recollection of autobiographical episodes were analyzed using temporal and spatial independent component analyses in combination with source localization. Autobiographical remembering was associated with an increase of spectral power in alpha and beta and a decrease in delta band. The increase of alpha power, as estimated by sLORETA, was most prominent in the posterior DMN, but was also observed in visual and motor cortices, prompting an assumption that it is associated with activation of DMN and inhibition of irrelevant sensory and motor areas. In line with data linking delta oscillations with aversive states, decrease of delta power was more pronounced in episodes associated with positive emotions, whereas episodes associated with negative emotions were accompanied by an increase of delta power. Vividness of recollection correlated positively with theta oscillations. These results highlight the leading role of alpha oscillations and the DMN in the processes accompanying autobiographical remembering. Copyright © 2014 Elsevier B.V. All rights reserved.
Angular correlation in positron annihilation
International Nuclear Information System (INIS)
Arponen, J.; Pajanne, E.
1978-01-01
The angular correlation of the two gamma quanta emitted when a thermalized positron annihilates with metallic conduction electrons is investigated by applying the newly developed theory of electron gas as a system of interacting collective excitations. The method leads in a natural way to the appearance of high-momentum components (i.e. pair momentum p>psub(F) in the annihilation radiation already in the case of annihilation with conduction electrons only. The amount of these components is significant approximately (10 %) in a dilute electron gas (like alkali metals), but fairly irrelevant for higher densities. The momentum-dependence of the enhancement factor for a dense system (with rsub(s) approximately equal to 2) agrees well both with the earlier theories due to Kahana and others, and also with recent accurate experimental observations. As rsub(s) increases into the alkali-metal region, the enhancement factor for p< psub(F) becomes relatively more and more constant, in contrast with the trend in the Kahana theory. In this density regime the experimental results seem to vary widely, although most of them desagree with the present prediction. We discuss the possible discrepancy and try to account for the effects of the core annihilation by a simple model. (author)
Information-causality and extremal tripartite correlations
International Nuclear Information System (INIS)
Yang, Tzyh Haur; Cavalcanti, Daniel; Almeida, Mafalda L; Teo, Colin; Scarani, Valerio
2012-01-01
We study the principle of information-causality (IC) in the presence of extremal no-signaling correlations on a tripartite scenario. We prove that all, except one, of the non-local correlations lead to violation of IC. The remaining non-quantum correlation is shown to satisfy any bipartite physical principle. (paper)
RAYLEIGH SCATTERING MODELS WITH CORRELATION INTEGRAL
Directory of Open Access Journals (Sweden)
S. F. Kolomiets
2014-01-01
Full Text Available This article offers one of possible approaches to the use of the classical correlation concept in Rayleigh scattering models. Classical correlation in contrast to three types of correlations corresponding to stochastic point flows opens the door to the efficient explanation of the interaction between periodical structure of incident radiation and discreet stochastic structure of distributed scatters typical for Rayleigh problems.
Functional Multiple-Set Canonical Correlation Analysis
Hwang, Heungsun; Jung, Kwanghee; Takane, Yoshio; Woodward, Todd S.
2012-01-01
We propose functional multiple-set canonical correlation analysis for exploring associations among multiple sets of functions. The proposed method includes functional canonical correlation analysis as a special case when only two sets of functions are considered. As in classical multiple-set canonical correlation analysis, computationally, the…
Correlation Coefficients: Appropriate Use and Interpretation.
Schober, Patrick; Boer, Christa; Schwarte, Lothar A
2018-05-01
Correlation in the broadest sense is a measure of an association between variables. In correlated data, the change in the magnitude of 1 variable is associated with a change in the magnitude of another variable, either in the same (positive correlation) or in the opposite (negative correlation) direction. Most often, the term correlation is used in the context of a linear relationship between 2 continuous variables and expressed as Pearson product-moment correlation. The Pearson correlation coefficient is typically used for jointly normally distributed data (data that follow a bivariate normal distribution). For nonnormally distributed continuous data, for ordinal data, or for data with relevant outliers, a Spearman rank correlation can be used as a measure of a monotonic association. Both correlation coefficients are scaled such that they range from -1 to +1, where 0 indicates that there is no linear or monotonic association, and the relationship gets stronger and ultimately approaches a straight line (Pearson correlation) or a constantly increasing or decreasing curve (Spearman correlation) as the coefficient approaches an absolute value of 1. Hypothesis tests and confidence intervals can be used to address the statistical significance of the results and to estimate the strength of the relationship in the population from which the data were sampled. The aim of this tutorial is to guide researchers and clinicians in the appropriate use and interpretation of correlation coefficients.
Using correlation functions as free decays
DEFF Research Database (Denmark)
Brincker, Rune; Amador, Sandro; Juul, Martin
It is a general assumption in OMA that correlation functions are free decays. In multiple input OMA this assumption also implies that any column in the correlation function matrix is to be considered as multiple output free decays. This assumption is discussed in this paper together with issues...... concerning estimation and application of correlations functions in OMA....
Multiparty correlation measure based on the cumulant
International Nuclear Information System (INIS)
Zhou, D. L.; Zeng, B.; Xu, Z.; You, L.
2006-01-01
We propose a genuine multiparty correlation measure for a multiparty quantum system as the trace norm of the cumulant of the state. The legitimacy of our multiparty correlation measure is explicitly demonstrated by proving it satisfies the five basic conditions required for a correlation measure. As an application we construct an efficient algorithm for the calculation of our measures for all stabilizer states
Correlation Measurements on Small Mobile Devices
DEFF Research Database (Denmark)
Yanakiev, Boyan Radkov; Nielsen, Jesper Ødum; Christensen, Morten
2012-01-01
Here, analysis of the antenna correlation at the design stage is done, with focus on measurement techniques. Various theoretical definitions of correlations are used with the corresponding measured data required. The problems related to the coaxial measurement cables, when calculating correlation...
Ultrafast dynamics of correlated electrons
International Nuclear Information System (INIS)
Rettig, Laurenz
2012-01-01
This work investigates the ultrafast electron dynamics in correlated, low-dimensional model systems using femtosecond time- and angle-resolved photoemission spectroscopy (trARPES) directly in the time domain. In such materials, the strong electron-electron (e-e) correlations or coupling to other degrees of freedom such as phonons within the complex many-body quantum system lead to new, emergent properties that are characterized by phase transitions into broken-symmetry ground states such as magnetic, superconducting or charge density wave (CDW) phases. The dynamical processes related to order like transient phase changes, collective excitations or the energy relaxation within the system allow deeper insight into the complex physics governing the emergence of the broken-symmetry state. In this work, several model systems for broken-symmetry ground states and for the dynamical charge balance at interfaces have been studied. In the quantum well state (QWS) model system Pb/Si(111), the charge transfer across the Pb/Si interface leads to an ultrafast energetic stabilization of occupied QWSs, which is the result of an increase of the electronic confinement to the metal film. In addition, a coherently excited surface phonon mode is observed. In antiferromagnetic (AFM) Fe pnictide compounds, a strong momentum-dependent asymmetry of electron and hole relaxation rates allows to separate the recovery dynamics of the AFM phase from electron-phonon (e-ph) relaxation. The strong modulation of the chemical potential by coherent phonon modes demonstrates the importance of e-ph coupling in these materials. However, the average e-ph coupling constant is found to be small. The investigation of the excited quasiparticle (QP) relaxation dynamics in the high-T c 4 superconductor Bi 2 Sr 2 CaCu 2 O 8+δ reveals a striking momentum and fluence independence of the QP life times. In combination with the momentum-dependent density of excited QPs, this demonstrates the suppression of momentum
Ultrafast dynamics of correlated electrons
Energy Technology Data Exchange (ETDEWEB)
Rettig, Laurenz
2012-07-09
This work investigates the ultrafast electron dynamics in correlated, low-dimensional model systems using femtosecond time- and angle-resolved photoemission spectroscopy (trARPES) directly in the time domain. In such materials, the strong electron-electron (e-e) correlations or coupling to other degrees of freedom such as phonons within the complex many-body quantum system lead to new, emergent properties that are characterized by phase transitions into broken-symmetry ground states such as magnetic, superconducting or charge density wave (CDW) phases. The dynamical processes related to order like transient phase changes, collective excitations or the energy relaxation within the system allow deeper insight into the complex physics governing the emergence of the broken-symmetry state. In this work, several model systems for broken-symmetry ground states and for the dynamical charge balance at interfaces have been studied. In the quantum well state (QWS) model system Pb/Si(111), the charge transfer across the Pb/Si interface leads to an ultrafast energetic stabilization of occupied QWSs, which is the result of an increase of the electronic confinement to the metal film. In addition, a coherently excited surface phonon mode is observed. In antiferromagnetic (AFM) Fe pnictide compounds, a strong momentum-dependent asymmetry of electron and hole relaxation rates allows to separate the recovery dynamics of the AFM phase from electron-phonon (e-ph) relaxation. The strong modulation of the chemical potential by coherent phonon modes demonstrates the importance of e-ph coupling in these materials. However, the average e-ph coupling constant is found to be small. The investigation of the excited quasiparticle (QP) relaxation dynamics in the high-T{sub c}4 superconductor Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+δ} reveals a striking momentum and fluence independence of the QP life times. In combination with the momentum-dependent density of excited QPs, this demonstrates the
Concentric retinitis pigmentosa: clinicopathologic correlations.
Milam, A H; De Castro, E B; Smith, J E; Tang, W X; John, S K; Gorin, M B; Stone, E M; Aguirre, G D; Jacobson, S G
2001-10-01
Progressive concentric (centripetal) loss of vision is one pattern of visual field loss in retinitis pigmentosa. This study provides the first clinicopathologic correlations for this form of retinitis pigmentosa. A family with autosomal dominant concentric retinitis pigmentosa was examined clinically and with visual function tests. A post-mortem eye of an affected 94 year old family member was processed for histopathology and immunocytochemistry with retinal cell specific antibodies. Unrelated simplex/multiplex patients with concentric retinitis pigmentosa were also examined. Affected family members of the eye donor and patients from the other families had prominent peripheral pigmentary retinopathy with more normal appearing central retina, good visual acuity, concentric field loss, normal or near normal rod and cone sensitivity within the preserved visual field, and reduced rod and cone electroretinograms. The eye donor, at age 90, had good acuity and function in a central island. Grossly, the central region of the donor retina appeared thinned but otherwise normal, while the far periphery contained heavy bone spicule pigment. Microscopically the central retina showed photoreceptor outer segment shortening and some photoreceptor cell loss. The mid periphery had a sharp line of demarcation where more central photoreceptors were near normal except for very short outer segments and peripheral photoreceptors were absent. Rods and cones showed abrupt loss of outer segments and cell death at this interface. It is concluded that concentric retinitis pigmentosa is a rare but recognizable phenotype with slowly progressive photoreceptor death from the far periphery toward the central retina. The disease is retina-wide but shows regional variation in severity of degeneration; photoreceptor death is severe in the peripheral retina with an abrupt edge between viable and degenerate photoreceptors. Peripheral to central gradients of unknown retinal molecule(s) may be defective
Does asymmetric correlation affect portfolio optimization?
Fryd, Lukas
2017-07-01
The classical portfolio optimization problem does not assume asymmetric behavior of relationship among asset returns. The existence of asymmetric response in correlation on the bad news could be important information in portfolio optimization. The paper applies Dynamic conditional correlation model (DCC) and his asymmetric version (ADCC) to propose asymmetric behavior of conditional correlation. We analyse asymmetric correlation among S&P index, bonds index and spot gold price before mortgage crisis in 2008. We evaluate forecast ability of the models during and after mortgage crisis and demonstrate the impact of asymmetric correlation on the reduction of portfolio variance.
Correlations in Relaxed Clusters of Galaxies
Directory of Open Access Journals (Sweden)
Babyk Iu.
2014-03-01
Full Text Available The correlations among different quantities in galaxy clusters, observed by Newman et al. (2013a,b, are investigated. We find an anti-correlation among the slope α, the effective radius, Re, and a correlation among the core radius rcore and Re. Moreover, the mass inside 100 kpc (mainly dark matter is correlated with the mass inside 5 kpc (mainly baryons. The listed correlations can be understood in a two phase formation model: the first dissipative phase forming the brightest cluster galaxies, and the second dissipationless phase, in which the inner density profile is flattened by the interaction of baryonic clumps and the dark matter halo through dynamical friction.
Noise correlations in cosmic microwave background experiments
Dodelson, Scott; Kosowsky, Arthur; Myers, Steven T.
1995-01-01
Many analysis of microwave background experiments neglect the correlation of noise in different frequency of polarization channels. We show that these correlations, should they be present, can lead to serve misinterpretation of an experiment. In particular, correlated noise arising from either electronics or atmosphere may mimic a cosmic signal. We quantify how the likelihood function for a given experiment varies with noise correlation, using both simple analytic models and actual data. For a typical microwave background anisotropy experiment, noise correlations at the level of 1% of the overall noise can seriously reduce the significance of a given detection.
Factorial correlators: angular scaling within QCD jets
International Nuclear Information System (INIS)
Peschanski, R.
2001-01-01
Factorial correlators measure the amount of dynamical correlation in the multiplicity between two separated phase-space windows. We present the analytical derivation of factorial correlators for a QCD jet described at the double logarithmic (DL) accuracy. We obtain a new angular scaling property for properly normalized correlators between two solid-angle cells or two rings around the jet axis. Normalized QCD factorial correlators scale with the angular distance and are independent of the window size. Scaling violations are expected beyond the DL approximation, in particular from the subject structure. Experimental tests are feasible, and thus would be welcome. (orig.)
Fully exponentially correlated wavefunctions for small atoms
Energy Technology Data Exchange (ETDEWEB)
Harris, Frank E. [Department of Physics, University of Utah, Salt Lake City, UT 84112 and Quantum Theory Project, University of Florida, P.O. Box 118435, Gainesville, FL 32611 (United States)
2015-01-22
Fully exponentially correlated atomic wavefunctions are constructed from exponentials in all the interparticle coordinates, in contrast to correlated wavefunctions of the Hylleraas form, in which only the electron-nuclear distances occur exponentially, with electron-electron distances entering only as integer powers. The full exponential correlation causes many-configuration wavefunctions to converge with expansion length more rapidly than either orbital formulations or correlated wavefunctions of the Hylleraas type. The present contribution surveys the effectiveness of fully exponentially correlated functions for the three-body system (the He isoelectronic series) and reports their application to a four-body system (the Li atom)
Energy Technology Data Exchange (ETDEWEB)
Parker, K [Atomic Weapons Research Establishment, Aldermaston (United Kingdom)
1962-03-15
The AWRE punched-card library of neutron cross-sections is described together with associated IBM-7090 programmes which process this data to give group-averaged cross-sections for use in Monte Carlo, Carlson S{sub n} and other multi-group neutronics calculations. The methods developed to deal with both isotropic and anisotropic elastic scattering are described. These include the multi-group transport approximation and the full treatment of anisotropic scattering using the Legendre polynomial moments of the scattering transfer matrix. The principles of group-constant formation are considered and illustrated by describing systems of group constants suitable for fast-reactor calculations. Practical problems such as the empirical adjustment of group constants to reproduce integral results and the collapsing of a many-group set of constants to give a few-group set are discussed. (author) [French] L'auteur decrit le fichier de cartes perforees sur lesquelles on enregistre a l'Atomic Weapons Research Establishment (AWRE) les sections efficaces neutroniques ainsi que les programmes IBM-7090 associes qui sont employes pour le traitement de ces informations, en vue d'obtenir des sections efficaces moyennes par groupe pouvant servir aux calculs de neutroniques a plusieurs groupes, effectues a l'aide des methodes de Monte-Carlo, S{sub n} de Carlson et autres methodes. L'auteur expose ensuite les methodes mises au point roda etudier la diffusion elastique, tant isotrope qu'anisotrope. Elles comprennent l'approximation de transport a plusieurs groupes, ainsi que le traitement complet de la diffusion anisotrope par les moments polynomiaux de Legendre de la matrice de transfert de la diffusion. L'auteur examine les principes de la formation des constantes de groupes; a titre d'illustration, il decrit les systemes de constantes de groupes qui se pretent aux calculs de reacteurs a neutrons rapides. Il expose quelques problemes pratiques, tels que l'ajustement empirique des
Bunches of random cross-correlated sequences
International Nuclear Information System (INIS)
Maystrenko, A A; Melnik, S S; Pritula, G M; Usatenko, O V
2013-01-01
The statistical properties of random cross-correlated sequences constructed by the convolution method (likewise referred to as the Rice or the inverse Fourier transformation) are examined. We clarify the meaning of the filtering function—the kernel of the convolution operator—and show that it is the value of the cross-correlation function which describes correlations between the initial white noise and constructed correlated sequences. The matrix generalization of this method for constructing a bunch of N cross-correlated sequences is presented. Algorithms for their generation are reduced to solving the problem of decomposition of the Fourier transform of the correlation matrix into a product of two mutually conjugate matrices. Different decompositions are considered. The limits of weak and strong correlations for the one-point probability and pair correlation functions of sequences generated by the method under consideration are studied. Special cases of heavy-tailed distributions of the generated sequences are analyzed. We show that, if the filtering function is rather smooth, the distribution function of generated variables has the Gaussian or Lévy form depending on the analytical properties of the distribution (or characteristic) functions of the initial white noise. Anisotropic properties of statistically homogeneous random sequences related to the asymmetry of a filtering function are revealed and studied. These asymmetry properties are expressed in terms of the third- or fourth-order correlation functions. Several examples of the construction of correlated chains with a predefined correlation matrix are given. (paper)
Performance highlights of the ALMA correlators
Baudry, Alain; Lacasse, Richard; Escoffier, Ray; Webber, John; Greenberg, Joseph; Platt, Laurence; Treacy, Robert; Saez, Alejandro F.; Cais, Philippe; Comoretto, Giovanni; Quertier, Benjamin; Okumura, Sachiko K.; Kamazaki, Takeshi; Chikada, Yoshihiro; Watanabe, Manabu; Okuda, Takeshi; Kurono, Yasutake; Iguchi, Satoru
2012-09-01
Two large correlators have been constructed to combine the signals captured by the ALMA antennas deployed on the Atacama Desert in Chile at an elevation of 5050 meters. The Baseline correlator was fabricated by a NRAO/European team to process up to 64 antennas for 16 GHz bandwidth in two polarizations and another correlator, the Atacama Compact Array (ACA) correlator, was fabricated by a Japanese team to process up to 16 antennas. Both correlators meet the same specifications except for the number of processed antennas. The main architectural differences between these two large machines will be underlined. Selected features of the Baseline and ACA correlators as well as the main technical challenges met by the designers will be briefly discussed. The Baseline correlator is the largest correlator ever built for radio astronomy. Its digital hybrid architecture provides a wide variety of observing modes including the ability to divide each input baseband into 32 frequency-mobile sub-bands for high spectral resolution and to be operated as a conventional 'lag' correlator for high time resolution. The various observing modes offered by the ALMA correlators to the science community for 'Early Science' are presented, as well as future observing modes. Coherently phasing the array to provide VLBI maps of extremely compact sources is another feature of the ALMA correlators. Finally, the status and availability of these large machines will be presented.
Quantifying meta-correlations in financial markets
Kenett, Dror Y.; Preis, Tobias; Gur-Gershgoren, Gitit; Ben-Jacob, Eshel
2012-08-01
Financial markets are modular multi-level systems, in which the relationships between the individual components are not constant in time. Sudden changes in these relationships significantly affect the stability of the entire system, and vice versa. Our analysis is based on historical daily closing prices of the 30 components of the Dow Jones Industrial Average (DJIA) from March 15th, 1939 until December 31st, 2010. We quantify the correlation among these components by determining Pearson correlation coefficients, to investigate whether mean correlation of the entire portfolio can be used as a precursor for changes in the index return. To this end, we quantify the meta-correlation - the correlation of mean correlation and index return. We find that changes in index returns are significantly correlated with changes in mean correlation. Furthermore, we study the relationship between the index return and correlation volatility - the standard deviation of correlations for a given time interval. This parameter provides further evidence of the effect of the index on market correlations and their fluctuations. Our empirical findings provide new information and quantification of the index leverage effect, and have implications to risk management, portfolio optimization, and to the increased stability of financial markets.
Clustering stocks using partial correlation coefficients
Jung, Sean S.; Chang, Woojin
2016-11-01
A partial correlation analysis is performed on the Korean stock market (KOSPI). The difference between Pearson correlation and the partial correlation is analyzed and it is found that when conditioned on the market return, Pearson correlation coefficients are generally greater than those of the partial correlation, which implies that the market return tends to drive up the correlation between stock returns. A clustering analysis is then performed to study the market structure given by the partial correlation analysis and the members of the clusters are compared with the Global Industry Classification Standard (GICS). The initial hypothesis is that the firms in the same GICS sector are clustered together since they are in a similar business and environment. However, the result is inconsistent with the hypothesis and most clusters are a mix of multiple sectors suggesting that the traditional approach of using sectors to determine the proximity between stocks may not be sufficient enough to diversify a portfolio.
Robustness of quantum correlations against linear noise
International Nuclear Information System (INIS)
Guo, Zhihua; Cao, Huaixin; Qu, Shixian
2016-01-01
Relative robustness of quantum correlations (RRoQC) of a bipartite state is firstly introduced relative to a classically correlated state. Robustness of quantum correlations (RoQC) of a bipartite state is then defined as the minimum of RRoQC of the state relative to all classically correlated ones. It is proved that as a function on quantum states, RoQC is nonnegative, lower semi-continuous and neither convex nor concave; especially, it is zero if and only if the state is classically correlated. Thus, RoQC not only quantifies the endurance of quantum correlations of a state against linear noise, but also can be used to distinguish between quantum and classically correlated states. Furthermore, the effects of local quantum channels on the robustness are explored and characterized. (paper)
Correlates of Pediatric CPAP Adherence
Hawkins, Stephen M.M.; Jensen, Emily L.; Simon, Stacey L.; Friedman, Norman R.
2016-01-01
pathophysiology of and to develop adherence-promoting and alternative interventions for pediatric OSA. Citation: Hawkins SM, Jensen EL, Simon SL, Friedman NR. Correlates of pediatric CPAP adherence. J Clin Sleep Med 2016;12(6):879–884. PMID:27092702
Correlated Topic Vector for Scene Classification.
Wei, Pengxu; Qin, Fei; Wan, Fang; Zhu, Yi; Jiao, Jianbin; Ye, Qixiang
2017-07-01
Scene images usually involve semantic correlations, particularly when considering large-scale image data sets. This paper proposes a novel generative image representation, correlated topic vector, to model such semantic correlations. Oriented from the correlated topic model, correlated topic vector intends to naturally utilize the correlations among topics, which are seldom considered in the conventional feature encoding, e.g., Fisher vector, but do exist in scene images. It is expected that the involvement of correlations can increase the discriminative capability of the learned generative model and consequently improve the recognition accuracy. Incorporated with the Fisher kernel method, correlated topic vector inherits the advantages of Fisher vector. The contributions to the topics of visual words have been further employed by incorporating the Fisher kernel framework to indicate the differences among scenes. Combined with the deep convolutional neural network (CNN) features and Gibbs sampling solution, correlated topic vector shows great potential when processing large-scale and complex scene image data sets. Experiments on two scene image data sets demonstrate that correlated topic vector improves significantly the deep CNN features, and outperforms existing Fisher kernel-based features.
Image correlation method for DNA sequence alignment.
Curilem Saldías, Millaray; Villarroel Sassarini, Felipe; Muñoz Poblete, Carlos; Vargas Vásquez, Asticio; Maureira Butler, Iván
2012-01-01
The complexity of searches and the volume of genomic data make sequence alignment one of bioinformatics most active research areas. New alignment approaches have incorporated digital signal processing techniques. Among these, correlation methods are highly sensitive. This paper proposes a novel sequence alignment method based on 2-dimensional images, where each nucleic acid base is represented as a fixed gray intensity pixel. Query and known database sequences are coded to their pixel representation and sequence alignment is handled as object recognition in a scene problem. Query and database become object and scene, respectively. An image correlation process is carried out in order to search for the best match between them. Given that this procedure can be implemented in an optical correlator, the correlation could eventually be accomplished at light speed. This paper shows an initial research stage where results were "digitally" obtained by simulating an optical correlation of DNA sequences represented as images. A total of 303 queries (variable lengths from 50 to 4500 base pairs) and 100 scenes represented by 100 x 100 images each (in total, one million base pair database) were considered for the image correlation analysis. The results showed that correlations reached very high sensitivity (99.01%), specificity (98.99%) and outperformed BLAST when mutation numbers increased. However, digital correlation processes were hundred times slower than BLAST. We are currently starting an initiative to evaluate the correlation speed process of a real experimental optical correlator. By doing this, we expect to fully exploit optical correlation light properties. As the optical correlator works jointly with the computer, digital algorithms should also be optimized. The results presented in this paper are encouraging and support the study of image correlation methods on sequence alignment.
Leamon, R. J.; McIntosh, S. W.
2017-12-01
Establishing a solid physical connection between solar and tropospheric variability has posed a considerable challenge across the spectrum of Earth-system science. Over the past few years a new picture to describe solar variability has developed, based on observing, understanding and tracing the progression, interaction and intrinsic variability of the magnetized activity bands that belong to the Sun's 22-year magnetic activity cycle. The intra- and extra-hemispheric interaction of these magnetic bands appear to explain the occurrence of decadal scale variability that primarily manifests itself in the sunspot cycle. However, on timescales of ten months or so, those bands posses their own internal variability with an amplitude of the same order of magnitude as the decadal scale. The latter have been tied to the existence of magnetized Rossby waves in the solar convection zone that result in surges of magnetic flux emergence that correspondingly modulate our star's radiative and particulate output. One of the most important events in the progression of these bands is their (apparent) termination at the solar equator that signals a global increase in magnetic flux emergence that becomes the new solar cycle. We look at the particulate and radiative implications of these termination points, their temporal recurrence and signature, from the Sun to the Earth, and show the correlated signature of solar cycle termination events and major oceanic oscillations that extend back many decades. A combined one-two punch of reduced particulate forcing and increased radiative forcing that result from the termination of one solar cycle and rapid blossoming of another correlates strongly with a shift from El Niño to La Niña conditions in the Pacific Ocean. This shift does not occur at solar minima, nor solar maxima, but at a particular, non-periodic, time in between. The failure to identify these termination points, and their relative irregularity, have inhibited a correlation to be
Hypothesis testing for differentially correlated features.
Sheng, Elisa; Witten, Daniela; Zhou, Xiao-Hua
2016-10-01
In a multivariate setting, we consider the task of identifying features whose correlations with the other features differ across conditions. Such correlation shifts may occur independently of mean shifts, or differences in the means of the individual features across conditions. Previous approaches for detecting correlation shifts consider features simultaneously, by computing a correlation-based test statistic for each feature. However, since correlations involve two features, such approaches do not lend themselves to identifying which feature is the culprit. In this article, we instead consider a serial testing approach, by comparing columns of the sample correlation matrix across two conditions, and removing one feature at a time. Our method provides a novel perspective and favorable empirical results compared with competing approaches. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Rod bundle burnout data and correlation comparisons
International Nuclear Information System (INIS)
Yoder, G.L.; Morris, D.G.; Mullins, C.B.
1985-01-01
Rod bundle burnout data from 30 steady-state and 3 transient tests were obtained from experiments performed in the Thermal Hydraulic Test Facility at the Oak Ridge National Laboratory. The tests covered a parameter range relevant to intact core reactor accidents ranging from large break to small break loss-ofcoolant conditions. Instrumentation within the 64-rod test section indicated that burnout occurred over an axial range within the bundle. The distance from the point where the first dry rod was detected to the point where all rods were dry was up to 60 cm in some of the tests. The burnout data should prove useful in developing new correlations for use in reactor thermalhydraulic codes. Evaluation of several existing critical heat flux correlations using the data show that three correlations, the Barnett, Bowring, and Katto correlations, perform similarly and correlate the data better than the Biasi correlation
Nuclear Matter Bulk Parameter Scales and Correlations
International Nuclear Information System (INIS)
Santos, B. M.; Delfino, A.; Dutra, M.; Lourenço, O.
2015-01-01
We study the arising of correlations among some isovector bulk parameters in nonrelativistic and relativistic hadronic mean-field models. For the former, we investigate correlations in the nonrelativistic (NR) limit of relativistic point-coupling models. We provide analytical correlations, for the NR limit model, between the symmetry energy and its derivatives, namely, the symmetry energy slope, curvature, skewness and fourth order derivative, discussing the conditions in which they are linear ones. We also show that some correlations presented in the NR limit model are reproduced for relativistic models presenting cubic and quartic self-interactions in its scalar field. As a direct application of such linear correlations, we remark its association with possible crossing points in the density dependence of the linearly correlated bulk parameter. (author)
Artificial intelligence approach to interwell log correlation
Energy Technology Data Exchange (ETDEWEB)
Lim, Jong-Se [Korea Maritime University, Pusan(Korea); Kang, Joo Myung [Seoul National University, Seoul(Korea); Kim, Jung Whan [Korea National Oil Corp., Anyang(Korea)
2000-04-30
This paper describes a new approach to automated interwell log correlation using artificial intelligence and principal component analysis. The approach to correlate wire line logging data is on the basis of a large set of subjective rules that are intended to represent human logical processes. The data processed are mainly the qualitative information such as the characteristics of the shapes extracted along log traces. The apparent geologic zones are identified by pattern recognition for the specific characteristics of log trace collected as a set of objects by object oriented programming. The correlation of zones between wells is made by rule-based inference program. The reliable correlation can be established from the first principal component logs derived from both the important information around well bore and the largest common part of variances of all available well log data. Correlation with field log data shows that this approach can make interwell log correlation more reliable and accurate. (author). 6 refs., 7 figs.
Angular correlations and high energy evolution
International Nuclear Information System (INIS)
Kovner, Alex; Lublinsky, Michael
2011-01-01
We address the question of to what extent JIMWLK evolution is capable of taking into account angular correlations in a high energy hadronic wave function. Our conclusion is that angular (and indeed other) correlations in the wave function cannot be reliably calculated without taking into account Pomeron loops in the evolution. As an example we study numerically the energy evolution of angular correlations between dipole scattering amplitudes in the framework of the large N c approximation to JIMWLK evolution (the 'projectile dipole model'). Target correlations are introduced via averaging over an (isotropic) ensemble of anisotropic initial conditions. We find that correlations disappear very quickly with rapidity even inside the saturation radius. This is in accordance with our physical picture of JIMWLK evolution. The actual correlations inside the saturation radius in the target QCD wave function, on the other hand, should remain sizable at any rapidity.
Decoherence-induced transition from photon correlation to anti-correlation
International Nuclear Information System (INIS)
Xu, Q
2014-01-01
Decoherence tends to induce the quantum-to-classical transition, which leads to a crucial obstacle in the realization of reliable quantum information processing. Counterintuitively, we propose that the decoherence due to phase decay brings about the switch from photon correlation to anti-correlation. Stronger decoherence also gives rise to an enhancement of the transition from photon correlation to anti-correlation. This breaks the conventional correlation of strong decoherence with fast decorrelation. (letters)
Quantum correlator outside a Schwarzschild black hole
Directory of Open Access Journals (Sweden)
Claudia Buss
2018-01-01
Full Text Available We calculate the quantum correlator in Schwarzschild black hole space–time. We perform the calculation for a scalar field in three different quantum states: Boulware, Unruh and Hartle–Hawking, and for points along a timelike circular geodesic. The results show that the correlator presents a global fourfold singularity structure, which is state-independent. Our results also show the different correlations in the three different quantum states arising in-between the singularities.
Reliability of Structural Systems with Correlated Elements
DEFF Research Database (Denmark)
Thoft-Christensen, Palle; Sørensen, John Dalsgaard
1982-01-01
Calculation of the probability of failure of a system with correlation members is usually a difficult and time-consuming numerical problem. However, for some types of systems with equally correlated elements this calculation can be performed in a simple way. This has suggested two new methods bas...... on so-called average and equivalent correlation coefficients. By using these methods approximate values for the probability of failure can easily be calculated. The accuracy of these methods is illustrated with examples....
Hidden neuronal correlations in cultured networks
International Nuclear Information System (INIS)
Segev, Ronen; Baruchi, Itay; Hulata, Eyal; Ben-Jacob, Eshel
2004-01-01
Utilization of a clustering algorithm on neuronal spatiotemporal correlation matrices recorded during a spontaneous activity of in vitro networks revealed the existence of hidden correlations: the sequence of synchronized bursting events (SBEs) is composed of statistically distinguishable subgroups each with its own distinct pattern of interneuron spatiotemporal correlations. These findings hint that each of the SBE subgroups can serve as a template for coding, storage, and retrieval of a specific information
Hadron correlations from recombination and fragmentation
Energy Technology Data Exchange (ETDEWEB)
Fries, Rainer J [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States)
2005-04-01
We review the formalism of quark recombination applied to the hadronization of a quark-gluon plasma. Evidence in favour of the quark recombination model is outlined. Recent work on parton correlations, leading to detectable correlations between hadrons, is discussed. Hot spots from completely quenched jets are a likely source of such correlations which appear to be jet like. It will be discussed how such a picture compares with measurement of associated hadron yields at RHIC.
Using nonlocal coherence to quantify quantum correlation
Pei, Pei; Wang, Wei; Li, Chong; Song, He-Shan
2010-01-01
We reexamine quantum correlation from the fundamental perspective of its consanguineous quantum property, the coherence. We emphasize the importance of specifying the tensor product structure of the total state space before discussing quantum correlation. A measure of quantum correlation for arbitrary dimension bipartite states using nonlocal coherence is proposed, and it can be easily generalized to the multipartite case. The quantification of non-entangled component within quantum correlati...
Particle correlations in high-multiplicity reactions
International Nuclear Information System (INIS)
Hayot, Fernand.
1976-01-01
A comprehensive review of the results obtained in the study of short range correlations in high-multiplicity events is presented: introduction of the fundamental short-range order hypothesis, introduction of clusters in nondiffractive events (only the production of identical, independent, and neutral clusters was considered); search for short range dynamical effects between particles coming from the decay of a same cluster by studying two-particle rapidity correlations in inclusive and semi-inclusive experiments; study of transverse momentum correlations [fr
Strongly correlating liquids and their isomorphs
Pedersen, Ulf R.; Gnan, Nicoletta; Bailey, Nicholas P.; Schröder, Thomas B.; Dyre, Jeppe C.
2010-01-01
This paper summarizes the properties of strongly correlating liquids, i.e., liquids with strong correlations between virial and potential energy equilibrium fluctuations at constant volume. We proceed to focus on the experimental predictions for strongly correlating glass-forming liquids. These predictions include i) density scaling, ii) isochronal superposition, iii) that there is a single function from which all frequency-dependent viscoelastic response functions may be calculated, iv) that...
Speckle pattern processing by digital image correlation
Directory of Open Access Journals (Sweden)
Gubarev Fedor
2016-01-01
Full Text Available Testing the method of speckle pattern processing based on the digital image correlation is carried out in the current work. Three the most widely used formulas of the correlation coefficient are tested. To determine the accuracy of the speckle pattern processing, test speckle patterns with known displacement are used. The optimal size of a speckle pattern template used for determination of correlation and corresponding the speckle pattern displacement is also considered in the work.
The illusionist game and hidden correlations
International Nuclear Information System (INIS)
Brida, G; Degiovanni, I P; Genovese, M; Meda, A; Olivares, S; Paris, M
2013-01-01
We suggest and demonstrate a new protocol based on correlated beams of light: the ‘optical illusionist game’. An ‘illusionist’ at first shows that if two uncorrelated light beams excited in the same Gaussian state are mixed in a beam splitter, then no correlations arise between them, as it was not present. On the other hand, when correlations with an ancillary state are exploited, the presence of the beam splitter can be unveiled. (paper)
Correlation of Helium Solubility in Liquid Nitrogen
VanDresar, Neil T.; Zimmerli, Gregory A.
2012-01-01
A correlation has been developed for the equilibrium mole fraction of soluble gaseous helium in liquid nitrogen as a function of temperature and pressure. Experimental solubility data was compiled and provided by National Institute of Standards and Technology (NIST). Data from six sources was used to develop a correlation within the range of 0.5 to 9.9 MPa and 72.0 to 119.6 K. The relative standard deviation of the correlation is 6.9 percent.
Correlation and prediction of gaseous diffusion coefficients.
Marrero, T. R.; Mason, E. A.
1973-01-01
A new correlation method for binary gaseous diffusion coefficients from very low temperatures to 10,000 K is proposed based on an extended principle of corresponding states, and having greater range and accuracy than previous correlations. There are two correlation parameters that are related to other physical quantities and that are predictable in the absence of diffusion measurements. Quantum effects and composition dependence are included, but high-pressure effects are not. The results are directly applicable to multicomponent mixtures.